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RELAT�RIO DE ACTIVIDADES 2005

RELAT�RIO DE ACTIVIDADES 2005

 2. RESEARCH TEAM AND INTERESTS

2.1. MEMBERS AND COLLABORATORS

������������� Ant�nio PASCOAL, Associate Professor (IST)

��������� ������������� SILVESTRE, Assistant Professor (IST)

������������� ������������� Paulo OLIVEIRA, Assistant Professor (IST)

������������� Ant�nio AGUIAR, Senior Researcher (IST/ISR)

������������� Rita CUNHA, Ph.D. St., FCT grantee

������������� Francisco TEIXEIRA, Ph.D. St., FCT grantee

������������� Sajjad FEKRIASL, Ph.D. St., FCT grantee

������������� Reza GHABCHELOO, Ph.D. St., FCT grantee

������������� Alex PE�AS, Ph.D. St., FCT grantee

������������� Jos� VASCONCELOS, Ph.D. St., FCT grantee

������������� S�rgio SILVA, Ph.D. St.

������������� Bruno CARDEIRA, Research Assistant, AdI grantee

������������� Bruno GUERREIRO, Research Assistant, AdI grantee

������������� Luis SEBASTI�O, Research Assistant, AdI grantee

������������� Manuel RUFINO, Research Assistant, AdI grantee

������������� Jo�o ALVES, Research Assistant, AdI grantee

������������� �������������

������������� Nuno PAULINO, Research Assistant

������������� Marco MORGADO, Research Assistant

������������� Duarte NUNES, Research Assistant

������������� Pedro GOMES, Research Assistant

������������� Pedro BATISTA, Research Assistant

������������� Loic BAMD�, Administrative Assistant

2.2. CURRENT RESEARCH INTERESTS

Introduction. Rationale for the work done at the Dynamical Systems and Ocean Robotics Laboratory (DSORL) of ISR.

There has been tremendous progress towards the development of autonomous robots for ocean exploration and exploitation. Autonomous robots do not place human lives at risk and allow access to otherwise unreachable regions of the ocean and its interfaces with the earth’s crust and the atmosphere. Equipped with advanced systems for navigation, guidance, control, and scientific data acquisition, they hold great potential to drastically simplify the task of acquiring marine data fast and in a cost-effective manner, without constant supervision of human operators. As such, they are steadily becoming the tool par excellence for ocean exploration and exploitation. Whereas most of the work done so far has been focused on the operation of surface and underwater vehicles (ocean segment), a trend is clearly visible where autonomous air vehicles (air segment) start to play an important role in ocean-related studies. Namely, by working either as single units (e.g. mapping of coastal areas and sand dunes) or in cooperation with marine vehicles (e.g. as transmission relays or as scouts to re-direct the operation of the latter).

Over the past years, the ISR/IST through its Dynamical Systems and Ocean Robotics Laboratory (DSORL) has been involved in a number of projects that have culminated with the deployment and operation of marine robots at sea. The European MARIUS/SOUV project, coordinated by ISR/IST, witnessed the development of the first civilian AUV (Autonomous Underwater Vehicle) in Europe. In the scope of the EU DESIBEL project coordinated by IFREMER, ISR/IST contributed to the development and at sea testing of an underwater shuttle for the transportation of benthic laboratories. The European ASIMOV project, also coordinated by ISR-IST, led to the development of advanced systems for the coordinated operation of the INFANTE AUV and the DELFIM ASC (Autonomous Surface Craft), both designed and built in Portugal under the auspices of the FCT. More recently, in the scope of the Portuguese CARAVELA project coordinated by IMAR-DOP/UAzores, the ISR-IST participated in the development of an autonomous research vessel for long range open ocean operation. The project is a landmark in the development of future ocean platforms that can replace normal research vessels in the more repetitive types of missions. During the past three years, ISR/IST has embarked in the development of three new marine robots: i) the DREAM ROV, for operations down to 1000 meters, in cooperation with CREMINER and the Faculty of Sciences of the University of Lisbon;� ii) MAYA, a miniaturized AUV for commercial and scientific applications, in cooperation with IMAR-DOP/UAzores and the National Institute of Oceanography, Goa, India, and iii) the DELFIM_X ASC, an improved version of the DELFIM ASC that will serve as a� platform to carry IRIS, an automatic surveying tool for the inspection of rubble-mound breakwaters, above and under the waterline.

Over the past three years, as a natural consequence of a longstanding collaboration program with the Department of Aeronautics and Astronautics of the Naval Postgraduate School of Monterey, California, USA, the ISR/IST has also started to apply some of the methodologies and technologies developed for ocean vehicles to the control of air robots (helicopters). This is justified in view of the increasing interest worldwide in the use of unmanned aerial robotic vehicles to perform airborne surveying tasks. As part of this effort, the ISR/IST has been instrumenting an unmanned robotic helicopter that will serve as an advanced platform for NGC (navigation, guidance, and control) system design, implementation, and testing. The platform is based on an industrial radio controlled helicopter that was equipped with a distributed real time computing network, a reliable wireless communication system, and sensing devices.� The activity pursued in this area is well rooted in scientific applications that require the use of autonomous air robots to accurately map coastal areas subjected to erosion, using airborne laser altimetry. In particular, project ALTICOPTER funded by the FCT envisions the use of a helicopter to map sand dunes along the Portuguese coast.�

Thee vehicles and tools that are built at IST/ISR play the dual role of i) advanced testbeds to field test new system theoretical concepts and hardware / software architectures for autonomous vehicle control, and ii) platforms for actual operations at sea, effectively paving the way for a fruitful symbiosis between marine science and technology.

In spite of the achievements made in the field of marine-related robotics, much work remains to be done to before such vehicles become ubiquitous instruments in the marine science “toolbox”. Meeting some of the challenges for advanced vehicle systems design as a contribution towards the development of faster, cheaper, and more efficient methods for the exploration and exploitation of the ocean, is one of the key objectives of the DSORL-ISR/IST. This objective called for the definition of a threefold research and development effort that addresses theoretical and practical engineering issues, as well as issues related to the interplay between marine sciences and marine technology. The main thrust of the work done at the DSORL is therefore directed along the following lines of action:

  • Contributing to furthering the knowledge in the general area of dynamical systems theory, with a special focus on nonlinear control theory and robust / adaptive control of highly uncertain systems.
  • Developing new analysis and design tools in the areas of navigation, guidance, and control (NGC) and applying them to the development of advanced systems for autonomous marine and aerial vehicles.
  • Investigating algorithms for trajectory tracking, path-following, and terrain-following control.
  • Studying and developing algorithms for feature-based navigation of autonomous underwater vehicles by exploiting the use of acoustic bathymetric terrain data and geomagnetic data.
  • Developing strategies for coordinated control of multiple autonomous vehicles (in the presence

������������� of severe communication constraints) that are well rooted in nonlinear system theory and ������������� networked control.

  • Advancing the development of software and hardware for the development of prototypes equipped with real-time operating systems for vehicle positioning, navigation, guidance, and control, as well as Mission Control.
  • Developing tools for acoustic and scientific equipment interfacing; performing actual missions at sea to transition from the laboratory to the real world and to foster the symbiosis between marine science and technology.

This work is being carried out in cooperation with institutions worldwide. Especially relevant are the cooperation links forged with India, Brazil, Norway, France, and the USA. At the same time, the group has been pursuing the execution of missions at sea to transition from the laboratory to the real world and to foster the symbiosis between marine science and technology. Missions take place in continental Portugal in the areas of Lisbon and Sines, and nearly every summer in the Azores in cooperation with the IMAR/DOP/UAzores using the prototype robots developed at ISR/IST.

Cooperative Links

The DSORL is involved in a number of projects and concerted actions with national and foreign institutions with the objective of advancing the development of engineering methodologies and equipments to the point where they can be used as versatile tools to expand our understanding of the oceans.� Representative institutions include the following:

  • Department of Mechanical Engineering and Aeronautics, Naval Postgraduate School, Monterey, CA (USA).
  • Center for Control Engineering and Computation at University of California, Santa Barbara; CA, USA.
  • Istituto Automazione Navale, Genova (Italy).
  • National Institute of Oceanography, Goa (India) – a memorandum of understanding has been signed between NIO and ISR.
  • Department of Engineering Cybernetics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
  • IFREMER (French Institute for Ocean Exploitation), France.
  • Department of Electrical Engineering of the University of Genova (Italy).
  • Department of Innovation Engineering, Univ. Lecce (Italy).
  • Department of Mechatronics, University of S�o Paulo (Brazil).
  • IMAR/DOP/UAzores - Department of Oceanography and Fisheries of the University of the Azores (Portugal).
  • CREMINER – The Geology Center of the Faculdade de Ci�ncias da Universidade de Lisboa (FCUL).
  • Instituto Geol�gico e Mineiro (IGM-Geological Survey of Portugal)
  • Laborat�rio Nacional de Engenharia Civil (Portugal).

Privileged links have been established with the IMAR/DOP/UAzores and CREMINER/FCUL, under Theme A (Techniques for Ocean Exploration) of the Laborat�rio Associado (Associated Laboratory) that is coordinated by ISR/IST. At a technological level, this concerted effort is in line with the current trend worldwide, aimed at the development of ocean sampling networks (OSN) providing a nested ocean observation capability through the coordinated control of many, mobile, networked sensor platforms. This trend shows clearly that advancements in marine robotics, communications, and information systems are steadily being brought to bear on the development of technologies to enable safer, better, faster, and far more efficient methodologies for the study of the oceans. At the same time, the plethora of engineering problems that must be tackled and solved in the context of ocean research pose considerable challenges to theoreticians and system designers.

Main Lines of Research and Development

The work reported addresses theoretical and practical issues. Striking an appropriate balance between the two factors is a hard task that requires the cooperation of many researchers / engineers, with expertise that covers a wide spectrum of technical fields. In 2005, 2 MSc and 7 PhD students, together with 5 research assistants and 4 members of the technical staff of IST were involved in the study of theoretical problems related to air and marine robotics; a group of hired Research Engineers, among which 3 (Luis Sebasti�o, Manuel Rufino, and Jo�o Alves) are senior researchers, have been contributing very actively to the research and development program of DSORL by tackling more practically oriented problems in the fields of vehicle and system development, as well as operations at sea in the Azores and Sines, together with our scientific partners in the Associated Laboratory. Worth stressing is the involvement of the IMAR/DOP/UAzores in the definition of vehicle requisites, selection of scientific sensor suites, and logistic support (lab space, support vessels and manpower).

At a theoretical level, and following the main trend established over the past years, the main lines of research that are being pursued at the DSORL include the following:

T1. Linear and nonlinear systems theory

T2. Robust Multiple-Model Adaptive Control (RMMAC): a new paradigm for robust control system design

T3. Design of Navigation, Guidance, and Control (NGC) systems for autonomous vehicles.

������������� T4. Motion Control of Single and Multiple Vehicles (air and marine robots) in the ������������� presence of communication constraints. Networked Control.

T5. Modelling, Parameter Estimation and Identification of Autonomous Underwater Vehicles (AUVs).

T6.� Multiple Vehicle Mission Control techniques

At a practical level, the emphasis is being placed on the following tasks in which the senior Research Assistants Jo�o Alves, Luis Sebasti�o, and Manuel Rufino have played leading roles

������������� P1. Design of AUVs and ASCs and on-board integration of scientific sensor suites and respective data acquisition / logging systems.

P2. Implementation of Navigation, Guidance, and Control (NGC) systems for autonomous vehicles.

P3. Hardware for coordinated navigation and motion control of multiple vehicles.

������������� P4. Hardware for Multiple Vehicle Mission Control using distributed computer architectures.

������������� P5. Tests and scientific missions with the robots developed.

The text that follows provides a brief description of some of the challenging topics for research and development listed above.

T1. Linear and nonlinear system theory

Study of theoretical tools for the analysis and design of linear and nonlinear control / filtering systems. The tools developed borrow from Linear Matrix Inequalities, Lyapunov stability theory, Backstepping techniques, ISS stability, and switching control. The applications centre around a vast range of problems that include, but are no limited to: a) path following and trajectory tracking for fully actuated and underactuated vehicles, b) speed, position, and attitude control, c) terrain tracking, and d) coordinated motion control of multiple autonomous platforms.

This line of research has received renewed impetus after Dr. Ant�nio Aguiar joined the group in mid-2005. The main lines of research that he is currently pursuing can be summarized as follows:

Nonlinear control: Many control systems of practical importance are inherently nonlinear. A common practice for control system design is to linearize the system to be controlled around some equilibrium or operating point through small perturbation state approximations. The key assumption is that the range of operation is restricted to a small region around the equilibrium on which the linear model remains valid. As a consequence, adequate control is only guaranteed in a neighborhood of the selected operating points. Moreover, performance can suffer significantly when the required operating range is large, such as when controlling an autonomous vehicle that executes maneuvers that emphasize its nonlinearity and cross-couplings. Together with Prof. Jo�o Hespanha,� from the University of California in Santa Barbara (UCLA), he derived in [AJ2] several control algorithms for motion control of autonomous vehicles (land and marine vehicles, in two and three-dimensional space) and showed that nonlinear Lyapunov-based designs can overcome the limitations mentioned above. The important common features that these designs share are the fact that they explicitly exploit the physical structure of the systems under consideration instead of “fighting” it. Moreover, the work is focused on systems that are underactuated and are therefore especially challenging since standard tools used to control nonlinear systems - such as feedback linearization and integrator backstepping - are not directly applicable.

Switched and hybrid systems: The last few years have witnessed increasing interest in the subject of hybrid control, i.e., systems that combine continuous dynamics with discrete logic. Much of this interest has been motivated by applications in such diverse fields as car automation and aeronautics, real time software, communication protocols, transportation, traffic control, power distribution, robotics, and consumer electronics. Modeling, analysis, control and synthesis of such systems pose a considerable number of challenging problems making still an active research area. Recently, a new class of switched systems was introduced and mathematical tools were developed to analyze their stability and disturbance/noise attenuation properties. This work, done in cooperation with Prof. Jo�o Hespanha (UCLA) and Prof. Ant�nio Pascoal, is summarized in [IC12]. In this work, a so-called seesaw control design methodology was proposed that yields closed-loop stability and robustness with respect to disturbance inputs. The methodology allowed for the design of a hybrid controller for an underactuated AUV that can operate in the presence of input disturbances and measurement noise. This was the culmination of a line of research on logic-based hybrid controllers to solve the stabilization problem for wheeled mobile robots and underactuated AUVs. A representative example of the work done is [AJ2], where an adaptive supervisory control algorithm was proposed for a class of nonlinear systems in the presence of possibly large modeling parametric uncertainty. The class of hybrid adaptive algorithms based on switching and logic is interesting from a theoretical standpoint and can overcome limitations of adaptive control based solely on continuous tuning.

Performance limitations: An important step in control (and plant) design process is to assess how the plant model may limit the level of achievable performance, and to examine tradeoffs leading to realistic design goals. Because of its fundamental implications, this has been a topic of enduring interest, in both classical and recent control literature. Dr. Ant�nio Aguiar�s interest in this topic is patent in [IJ1], where in cooperation with Prof. Jo�o Hespanha and Prof. Petar Kokotovic he investigated the limits of performance in reference-tracking and path-following for non-minimum phase systems and highlighted an essential difference between them. It is well-known that in the reference-tracking, for non-minimum phase systems, there exists a fundamental performance limitation in terms of a lower bound on the L2-norm of the tracking error, even when the control effort is free. In [J3] the authors showed that this is not the case for the less stringent path-following problem, where the control objective is to force the output to follow a geometric path without a timing law assigned to it. Furthermore, the same is true even when an additional desired speed assignment is imposed. This conceptual result is of great practical significance because the path-following formulation is convenient for many applications and it shows that the classical approach of recasting path-following as a reference tracking problem may introduce performance limitations that are not inherent in the original problem. This prompted a renewed interest in design of path following controllers for non-minimum phase systems. Recently he derived, together with the co-authors of [J3], analog limits of performance for a class of nonlinear systems [J2], [C3]. Following this trend, he organized a workshop on “New Developments in Control Performance Limitation Research: A Tale in the Network Age” for the 44th Conference on Decision and Control in Seville, (CDC'05), Spain, December 2005 (with Jie Chen, Rick Middleton, and Li Qiu).

Nonlinear observers: Over the last few decades there has been increasing interest in the design of observers for nonlinear systems. The extended Kalman filter is a widely used method for estimating the state of a nonlinear system. It is obtained by linearizing the nonlinear dynamics and the observation along the trajectory of the estimate. However, since it is only a local method, it often fails to converge. Several nonlinear observers using deterministic and stochastic approaches can be found in the literature: Lyapunov-like, Luenberger-like, high gain observers, sliding-mode observers, optimization-based, etc. In [J4], Dr. Ant�nio Aguiar and Prof. Jo�o Hespanha addressed the state estimation of systems with perspective outputs. In this work, minimum-energy estimators were constructed that produce an estimate of the state that is “most compatible” with the dynamics, in the sense that it requires the least amount of noise energy to explain the measured outputs. Under suitable observability assumptions, it was proved that the estimate converges globally asymptotically to the true value of the state in the absence of noise and disturbance. In the presence of noise, the estimate converges to a neighborhood of the true value of the state. Recently, this line of research led to the problem of estimating the state of a system with implicit outputs [C2]. The problem was formulated in the so-called deterministic H - infinity filtering setting by computing the value of the state that minimizes the induced L2-gain from disturbances to estimation error, while remaining compatible with the past observations. The key advantage of these approaches compared with the extended Kalman filter is that the resulting observers are globally convergent under appropriate observability assumptions and can therefore be used to design output-feedback controllers.

T2. Robust Multiple-Model Adaptive Control (RMMAC): a new paradigm for robust control system design

Following previous research efforts, the work of doctoral student Sajjad FekriAsl, supervised by Profs. Michael Athans and Ant�nio Pascoal, continued to focus on a novel Robust Multiple-Model Adaptive Control (RMMAC) architecture that explores an interesting and fruitful set of ideas set forth by Prof. Michael Athans. The new structure for robust control combines and integrates sophisticated identification methods and the state-of-the-art in robust control synthesis, using the mixed Mu- methodology for robust control of linear time-invariant systems subject to structured and unstructured uncertainty. The proposed RMMAC method does not seem to suffer from some of the ad-hoc design choices associated with the recent literature of using switching controllers using multiple-models. Moreover, RMMAC focuses upon robust-stability and robust-performance. The work has steadily progressed to a level where a methodology to design robust adaptive controllers for multiple-input multiple-ouput plants with parametric uncertainty and unmodeled dynamics is now available [AIJ7]. However, considerable work still remains to be done to fully extend the techniques developed so far for a large number of uncertain parameters. The work done was the subject of a Plenary Talk given by Prof. Michael Athans at the 16th IFAC World Congress, Praha, Czech Republic, 2005.

T3. Design of Navigation, Guidance, and Control (NGC) systems for autonomous vehicles.

This topic of research addresses the study of advanced systems for navigation, guidance, and control of autonomous vehicles using the techniques developed in T1. From a theoretical and even practical standpoint, some of the most challenging problems arise in the course of designing navigation and positioning systems for marine vehicles. Navigation refers to the problem of computing the linear position and attitude of an underwater platform and the respective linear and rotational rates. By positioning it is simply meant the problem of computing the position of an underwater platform. Recently there has also been great interest in the problem of joint attitude and position estimation (without immediate concern for the computation of the respective rates), based on so-called range/pseudo-range measurements. These three types of problems are being studied at ISR/IST. Special emphasis has been placed on the following key aspects:

i) design and fabrication of a moderate cost heading and attitude reference unit (work carried out under the supervision of Profs Paulo Oliveira and Carlos Silvestre) that has proven quite valuable in terms of evaluating different types of accelerometers and mechanical / fiber optic gyros, as well as affording hands on experience on the design and development of a unit that will equip future platforms, using hardware for real time distributed systems that is proprietary of ISR/IST. Work is also progressing on the development of a inertial navigation system aided by GPS, with applications to the control of aerial and surface vessels [IC2].

ii) study and practical evaluation of acoustics-based systems for underwater vehicle positioning by resorting to a system that consists of four surface buoys equipped with DGPS receptors and submerged underwater hydrophones (so-called GIB system). Each of the buoys receives the acoustic impulses emitted periodically by a synchronized pinger installed on-board an underwater vehicle and records their times of arrival. The buoys communicate via radio with a central station (typically on-board a support vessel) where the position of the underwater vehicle is computed. Due to the fact that position estimates are only available at the central station, this system is naturally suited for tracking applications. The emphasis has been placed on the study of estimation algorithms that can cope with outliers, latency in the measurements, and multiple acoustic trajectories. The theoretical work is being done by PhD student Alex Pe�as, under the supervision of Prof Paulo Oliveira and the co-supervision of Prof. Ant�nio Pascoal. Practical work involved the modification of the commercially-available GIB system to have direct access to the raw data at the buoys, followed by algorithm implementation and tests at sea for performance evaluation [AIJ6], [TR4]. Future work will aim at the development of a proprietary system for underwater target positioning, including the necessary systems for the emission and detection of acoustic signals.

Acoustic Underwater Positioning System

iii) Joint attitude and position estimation systems based on range/pseudo-range measurements have received the attention of the engineering community, as an alternative to more complex, expensive, and sophisticated Inertial Navigation Systems. A good feature of such systems is that they are drift-less and insensible to magnetic disturbances. The study on the limits of performance of such systems and the development of methodologies to solve the estimation of joint position and attitude problems, borrowing from tools from Riemannian geometry, have been pursued by PhD student Alex Pe�as, under the supervision of Prof Paulo Oliveira with the co-supervision of Prof. Ant�nio Pascoal and in tight cooperation with Prof. Jo�o Xavier of the Signal Processing Group [TR2], [TR3].

iii) Study and evaluation of the performance of feature based navigation algorithms. Navigation system design for the execution of long range missions with autonomous underwater vehicles (AUVs) in unstructured environments, resorting to a minimum of external sensors and yielding bounded error estimates, has been a major challenge in underwater robotics. The variations in the characteristics of the acoustic channel, coupled with noise and latency in sensor measurements, continuously degrade the accuracy of navigation systems along time, precluding their use in a number of interesting applications. External positioning systems have been proposed and successfully operated in the past and integrated in navigation systems for underwater applications. Unfortunately, all these systems provide only locally accurate measurements (a few square kilometres), take long time to deploy and are hard to calibrate, and constrain heavily the missions that can be executed with AUVs. There simply is no remedy to this situation when the vehicles execute missions in open water, far away from the seabed and the sea surface, over long distances, with no clear landmarks “in sight”.

The situation is completely different when a vehicle is asked to repeatedly survey an area where there are conspicuous landmarks (e.g. conspicuous terrain features, strong magnetic or gravimetric signatures, etc.). In this case, it is best to try and use this information to develop navigation system capable of correcting for the drift that is inherent to “inertial navigation-like” systems. This entails the use of bathymetric, geomagnetic, and gravimetric data.

To meet some of the above challenges, Prof. Paulo Oliveira continued his research effort towards the development of terrain based navigation systems (based on bathymetric maps) by resorting to the use of unsupervised optimal processing techniques of random signals, namely Principal Component Analysis (PCA) [IC4]. He also pursued the development of Multiple Model Adaptive Estimator (MMAE) Terrain Reference Navigation Systems for underwater vehicles using Eigen Analysis [IC1], [IC3]. The performance of the algorithms derived was studied for a large set of terrains carefully chosen, providing bounds on the expected stochastic performance for the problem at hand, resorting to a series of Monte Carlo experiments. The results obtained pave the way to the use of the proposed sensor in real positioning applications for underwater robotics.

In a parallel effort, doctoral student Francisco Teixeira (under the supervision of Prof. Ant�nio Pascoal) continued his research on the subject of underwater vehicle navigation using bathymetric data. In his work, he derived a new type of particle filter that effectively merges information provided by a Doppler log, an attitude unit, and a set of echosounders. In the course of his work, an efficient way was found to model the type of information provided by an echosounder as a function of the terrain (local slope, roughness, etc.). Stimulating simulation results obtained with a digital terrain map of the D. Jo�o de Castro seamount show the potential of the filter to the development of terrain based navigation systems [IC18], [TR9]. He also evaluated the performance achieved by exploiting the use of multiple echo-sounders. Recently, he started to address the problem of AUV navigation using geomagnetic data [TR10]. Interestingly enough, an extensive literature survey reveals that only a few papers on this issue have appeared in the literature. The subject is challenging both from a theoretical and practical standpoint: theoretically, it requires that tools from Geomagnetism be used (namely, upward and downward continuation of potential geomagnetic fields); the practical issues to be resolved revolve around the need to estimate and cancel out the influence of the magnetic field generated by the platform on which the measuring device (magnetometer) is installed. Contacts have been established with Dr. Dana Yoeger of the Woods Hole Oceanographic Institution, USA to share geo-referenced magnetic data acquired with the Autonomous Benthic Explorer (ABE) AUV over the D. Juan de Fuca Ridge.

AUV terrain-based navigation; Bathymetric map of the D. Jo�o de Castro seamount (Azores, Portugal)

T4. Motion Control of single and multiple vehicles (air and marine robots) in the presence of communication constraints. Networked Control.

At ISR/IST there has been considerable research activity on the problems of motion control of single and multiples autonomous vehicles. The key problems under study are summarized below.

Motion control of single autonomous vehicles: The ever increasing sophistication of autonomous vehicles is steadily paving the way for the execution of complex missions without direct supervision of human operators. A key enabling element for the execution of such missions is the availability of advance systems for motion control of autonomous vehicles. The past few decades have witnessed considerable interest in this area. The problems of motion control addressed in the literature can be roughly classified into three groups: point stabilization, where the goal is to stabilize a vehicle at a given target point with a desired orientation; trajectory tracking, where the vehicle is required to track a time parameterized reference, and path following, where the vehicle is required to converge to and follow a desired geometric path, without a timing law assigned to it. For underactuated autonomous vehicles, i.e., systems with a smaller number of control inputs than the number of independent generalized coordinates, motion control is still an active research topic. The study of these systems is motivated by the fact that it is usually costly and often impractical (due to weight, reliability, complexity, and efficiency considerations) to fully actuate autonomous vehicles. Typical examples of underactuated systems include robot manipulators, wheeled robots, walking robots, spacecraft, aircraft, helicopters, missiles, surface vessels, and underwater vehicles.

Over the past years, Dr. Ant�nio Aguiar - in cooperation with Prof. Jo�o Hespanha –has been researching the problem of motion control of underactuated autonomous vehicles and nonholonomic systems. Recently, in [AIJ2] they proposed a solution to the trajectory-tracking and path-following problem for underactuated autonomous vehicles in the presence of possibly large modeling parametric uncertainty. For a general class of vehicles moving in either two or three-dimensional space, they demonstrated how adaptive switching supervisory control can be combined with a nonlinear Lyapunov-based tracking control law to design a hybrid controller that yields global boundedness and convergence of the position tracking error to a small neighborhood, and robustness to parametric modeling uncertainty. These results are illustrated in the context of two vehicle control applications: a hovercraft (moving on a planar surface) and an underwater vehicle (moving in three-dimensional space). Collaborative work of Dr. Ant�nio Aguiar, Prof. Jo�o Hespanha, and Prof. Ant�nio Pascoal, has also led to the development of a new methodology for the design of switching control system for motion control of underactuated vehicles [IC7]. A monograph on nonlinear motion control of underactuated autonomous vehicles (co-authored by Dr. Ant�nio Aguiar, Prof. Jo�o Hespanha, and Prof. Ant�nio Pascoal) that summarizes the work done has been finalized and accepted for publication. The monograph addresses the problems of point stabilization, trajectory tracking, and path following, and includes examples of applications to marine vehicles and a hovercraft.

Visual servo control. On a complementary vein, Dr. Ant�nio Aguiar and Prof. Jo�o Hespanha have been also doing research on control systems that utilize machine vision as a feedback sensor, also known as visual-servo control. This area poses considerable challenges and opportunities in control engineering and requires substantial research work on system analysis and design. Over the last decade, visual servoing applications have increased dramatically. The use of a vision system in closed-loop control schemes increases the flexibility and accuracy of robotic systems. Depending on the setup at hand, vision-based control can be used to perform many different tasks such as navigation, manipulation, tracking, etc. However, the use of vision systems introduces significant difficulties because of its nonlinearity and its extreme sensitivity to the environment. The environment is made by objects with complex geometry (shape), complex photometry (appearance) and complex dynamics (motion, deformation). In [J4], both authors explored the use of vision to solve the estimation of position and orientation of a mobile robot that uses a monocular charged-coupled-device (CCD) camera mounted onboard to observe the apparent motion of stationary points. The estimators proposed can deal directly with the usual problems associated with vision systems such as noise, latency and intermittency of observations. They have also developed and implemented a real-time system to control a mobile robot to park at a desired target using only vision [J4]. More recently, in [C2], they have derived an observer to estimate the position and attitude of an autonomous vehicle combining the measurements from an inertial measurement unit (IMU) and from a monocular CCD camera attached to the vehicle. Future work will address similar problems in the marine world.

Path Following for Air Vehicles. Under the guidance of Prof. Carlos Silvestre, doctoral student Rita Cunha, has been addressing the problem of steering an autonomous helicopter along a predefined 3-D path, while tracking a desired velocity profile (path-following). The solution to this problem relies on the definition of a path-dependent error space to express the dynamic model of the vehicle, which is expected to exhibit a high degree of directional accuracy. The methodology adopts a polytopic Linear Parameter Varying (LPV) representation with piecewise affine dependence on the parameters to accurately model the error dynamics over a wide flight-envelope. The synthesis problem is stated as a discrete-time H2 control problem for LPV systems and solved using Linear Matrix Inequalities (LMIs). To achieve better path-following performance, a preview control technique is adopted, which amounts to introducing a feedforward term driven by future path disturbances. Implementation of the nonlinear controller is addressed within the framework of gain-scheduling control theory using the so-called D-methodology. The effectiveness of the proposed controller has so far been assessed in simulation using the full nonlinear model of a small-scale helicopter [IC5] .

Terrain Contour Tracking for AUVs and Air Vehicles. Supervised by Prof. Carlos Silvestre, doctoral student Rita Cunha and Research Associate� Nuno Paulino have addressed the problem of terrain tracking for both autonomous underwater vehicles by taking into account the terrain characteristics ahead of the vehicles, as measured by dedicated sensors (e.g. two forward� looking echosounders in the case of AUVs) [AIJ4], [IC8], [TR5], [TR16]. The methodology adopted to solve the this problem amounts to posing it as a discrete time path following control problem where a conveniently defined error state space model of the plant is augmented with altitude (above the terrain) preview data. A piecewise affine parameter-dependent model representation is used to accurately describe the vehicle linearized error dynamics for a pre-defined set of operating regions. For each region, the synthesis problem is stated as a state feedback H2 control problem for affine parameter-dependent systems and solved using Linear Matrix Inequalities (LMIs). The resulting nonlinear controller is implemented in the scope of gain-scheduled control theory using so-called D-methodology. Future work will aim at applying the results obtained to the control of the INFANTE AUV and an autonomous helicopter. nonlinear model paving the way to the implementation and evaluation in tests at sea.

Coordinated/cooperative control of a group of autonomous vehicles: The past decade has witnessed the emergence of autonomous behaviours in single mobile systems, with applications to the safe operation of ground, air, and marine vehicles in the presence of changing and unknown environmental conditions The experience thus acquired is now steadily being brought to bear on the solutions to far more complex, albeit similar problems, that arise when multiple systems must work together. This shift of attention was brought about by the introduction of the concept of multiple autonomous vehicles performing missions cooperatively as an attractive alternative to the traditional single vehicle paradigm. The multiple vehicle approach offers several advantages such as increased efficiency, performance, reconfigurability and robustness, and new emerging capabilities. Furthermore, technological advances in communications and in miniaturization of electro-mechanical systems are making possible and relatively inexpensive the deployment of groups of networked vehicles in a number of environments. Some of the potential applications include tasks that involve searching and surveying as well as exploration and mapping in harsh environments. A cooperative network of autonomous vehicles can also adapt the behavior/configuration of the network in response to the measured environment in order to improve performance and optimize the detection and measurement of fields and features of particular interest. Furthermore, each vehicle could carry only a single sensor (per environmental variable of interest) making them less complex, and consequently increasing its reliability. Notice also that sensors may require considerable power or space and these are typically at a premium. On the other hand, the coordination of autonomous vehicles involves the design of distributed control laws with limited and disrupted communication, uncertainty and imperfect or partial measurements. This is particular significant for the case of underwater vehicles. These constraints together with safety, robustness and performance are critical properties that must be directly taken into account in the design of the control algorithms.

The above problems are extremely challenging, both from a theoretical and practical standpoint, and many of the simplest ones lie at the boundary of current tools and understanding. An aspect that is likely to be particularly important is the integration of controls, communications, computing, and networks. Today, dynamic system theory provides a rich methodology and a supporting set of mathematical principles and tools for analysis and design of navigation, guidance, and control systems for single autonomous vehicles. However, in this new context, many traditional approaches may no longer work and therefore it is imperative to develop new paradigms for designing robust, high performance multi-vehicle systems. To model the integration of physical continuous systems, event-based protocols, and real-time software, a framework of choice is to use hybrid systems. From the point of view of systems implementation, the solution is clearly to explore fast paced developments in the area of embedded systems.

At ISR/IST, there has been considerable research activity in this vibrant area towards the development of algorithms for coordinated motion control of marine vehicles. The interest of the group in this area goes back to approximately 10 years ago, when the so-called ASIMOV concept was first proposed in the scope of a European project coordinated by IST. The concept involves the concerted operation of an autonomous underwater vehicle (AUV) and an autonomous surface craft (ASC).� In this scenario, an autonomous surface craft (ASC) is required to follow a desired path accurately while an autonomous underwater vehicle (AUV) operating at a fixed depth is required to follow exactly the same horizontal path (shifted in the vertical coordinate), while tracking the ASC motion along that path.� See the joint figure.

Combined autonomous surface craft / autonomous underwater vehicle control.

The quest for hydrothermal vents using multiple AUVs equipped with methane sensors.

In this example, the AUV serves as a mobile sensor suite to acquire scientific data, while the ASC plays the role of a fast communication relay between the AUV and a support ship. Thus, the ASC effectively explores the fact that high data rate underwater communications can best be achieved if the emitter and the receiver are aligned along the same vertical line. Notice how both vehicles are required to follow exactly the same type of path (shifted in the vertical), which is imposed by the scientific missions at hand. Other challenging scenarios can of course be envisioned, namely using a fleet of underwater vehicles to detect the source of a hydrothermal vent by computing on-line and following the gradient of methane concentration.

The research done at IST/ISR in this area departs from mainstream work in that it focused on Coordinated Path Following: a set of vehicles is required to converge to and follow pre-assigned paths and, once on the paths, synchronize their motion so as to reach a desired formation pattern. Related work is being pursued by the group of Prof. Thor Fossen and Prof. Kristin Pettersen at the NTNU, Norway. This motivated the work PhD student Reza Ghabcheloo supervised by Profs Ant�nio Pascoal and Carlos Silvestre), in collaboration with Prof. Isaac Kaminer of the Naval Postgraduate School, Monterey, CA, USA. He has addressed the problem of steering a fleet of mobile robots along a set of given spatial paths, while keeping a desired inter-vehicle formation pattern. This problem arises for example when multiple vehicles are required to scan a given area in cooperation. In a possible mission scenario, one of the vehicles acts a leader and follows a path accurately, while the other vehicles follow paths that are naturally determined by the formation pattern imposed. However, other inter-vehicle coordination schemes are allowed. The solution proposed addresses explicitly the dynamics of the cooperating vehicles and the constraints imposed by the topology of the inter-vehicle communications network. Lyapunov-based techniques and graph theory are brought together to yield a decentralized control structure where the information exchanged among the robots is kept at a minimum. With the set-up proposed, path following (in space) and inter-vehicle coordination (in time) are essentially decoupled. Path following for each vehicle amounts to reducing a conveniently defined error variable to zero. Vehicle coordination is achieved by adjusting the speed of each of the vehicles along its path according to information on the positions and speeds of a subset of the other vehicles, as determined by the communications topology adopted. No other information is exchanged among the robots. In his work he obtained a formal proof of asymptotic stability (convergence and stability in the sense of Lyapunov) of the coordinated path following control scheme both for land robots and fully actuated underwater vehicles [AIJ5], [AIJ8], [AIJ5], [IC7], [IC10], [IC11], [TR7], [TR14]. More recently, by exploiting fruitful collaboration links with Dr. Ant�nio Aguiar, he has been working on the extension of the above results to a very general class of vehicles (thus allowing for the consideration of underactuated marine vehicles) while addressing explicitly the problems that arise due to� communication failures and communication delays. The mathematical machinery adopted borrows from the theory of systems with Brief Instabilities. The results obtained so far hold promise to the development of formal tools to study stability and performance of the coordinated behaviour of a fleet of vehicles.

Networked control. In many complex control systems, such as manufacturing plants, autonomous vehicles, aircraft, and spacecraft, communication networks are employed to exchange information and control signals between spatially distributed controllers, sensors and actuators. These control architectures, called networked control systems (NCSs), are being adopted in many application areas for a number of reasons including their low cost, reduced weight, and power requirements, simple installation and maintenance, and higher reliability. However, using a network presents some new challenges because the network itself is a dynamical system that exhibits characteristics that traditionally have not been taken into account in control system design. These special characteristics include quantization and time-delays and are a consequence of the fact that practical channels have only a limited bandwidth. Thus, a networked controller needs to be designed to take into account the communication channel. In [AIJ1], Dr. Ant�nio Aguiar and Prof. Jo�o Hespanha addressed these problems from the point of view of the observer designer. They investigated the problem of estimating the state of continuous-time systems with perspective outputs when the measured outputs are transmitted through a network. They considered measurements that arrive at discrete-time instants, are time-delayed, noisy, and may not be complete. An observer was designed that guarantees that the estimation error satisfies an input-to-state stability-like condition with respect to noise and disturbances. These results are expected to play a relevant role in the development of advanced systems for coordinated motion control (examined above).

T5. Modeling, Parameter Estimation and Identification of AUVs (Autonomous Underwater Vehicles).

In recent years, a new line of research arose out of the interaction with Prof. Ettore Barros from the Univ. S�o Paulo, Brasil, who spent his sabbatical license at ISR/IST in 2003-2004. His research program addressed the general problem of autonomous underwater vehicle (AUV) modelling and parameter estimation as a means to predict the expected dynamic performance of AUVs and thus guide their design phase well before they can be tested at sea.� This will shorten the time of vehicle design and development and reduce drastically the costs associated with intensive hydrodynamic tank tests.

Analytical and Semi-Empirical Methods for the estimation of AUV hydrodynamic derivatives were studied and applied to the estimation of the hydrodynamic derivatives of the MAYA AUV, an autonomous vehicle that is being developed under a joint Indian-Portuguese project. The parameter estimates were used to predict the behaviour of the vehicle in the vertical plane and horizontal planes and to assess the impact of stern plane size on its expected performance. The model obtained was instrumental in developing controllers for the AUV. Their performance will be assessed during missions with the real vehicle in India, in early 2006.

In the course of this work, cooperation agreements have been established with the Department of Engineering Cybernetics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, and the National Institute of Oceanography (NIO), Dona Paula, Goa, India. The NTNU has the facilities required to run hydrodynamics tank tests, while NIO has agreed to run AUV CFD analysis using parallel computing facilities available in India. A cooperation programme has also been established with Prof. Falc�o Campos (Dept. Mechanical Engineering of IST), an expert in hydrodynamics and propeller theory, who is interested in estimating some of the key hydrodynamic parameters of the MAYA AUV with a view to designing a high-efficiency propeller for increased vehicle autonomy. This work is being coordinated by Research Assistant Luis Sebasti�o.

T6.� Multiple Vehicle� Mission Control techniques

Over the past eight years, ISR/IST has steadily been developing methodologies for Mission Control which, after implementation using dedicated hardware and software architectures, can afford end-users the tools to seamlessly programming and execute missions with robotic vehicles in a completely autonomous mode. The main bulk of the work done so far led to CORAL, a Petri Net software application that is proprietary of ISR/IST and allows for mission programming and execution in real-time. Central to the development of CORAL was the concept of Vehicle Primitive (VP), a parameterized basic “action” of the vehicle being controlled that can be offered as a “resource” to the vehicle Mission Control System (MCS). Examples of Vehicle Primitives include Heading Command Tracking, Depth Command Tracking, and Terrain Following, to name but a few.

In a great number of mission scenarios involving cooperation among multiple vehicles one must extend the tools available for single vehicles to ensure the coordinated operation of a complete fleet. Thus, one is confronted with the need to develop a set of Multi-Vehicle Primitives (MVP) that can be offered as “resources” to the Coordination Mission Control System (CMCS) in charge of the complete multi-vehicle operation. Examples include the Multi-Vehicle Primitives aimed at implementing the following:

1. Combined autonomous surface vehicle / autonomous underwater vehicle control. In this scenario, an autonomous surface craft (ASV) is required to follow a desired path accurately while an autonomous underwater vehicle (AUV) operating at a fixed depth is required to follow exactly the same horizontal path (shifted in the vertical coordinate), while tracking the ASV motion along that path. In this example the AUV serves as a mobile sensor suite to acquire scientific data, while the ASC plays the role of a fast communication relay between the AUV and a support ship. Notice how both vehicles are required to follow exactly the same type of path, which is imposed by the scientific missions at hand. Similar comments apply to the combined operation of an ASV to which a remotely operated vehicle is connected through an umbilical

2. Cooperative autonomous underwater vehicle control: video acquisition. This scenario occurs when an underwater vehicle carries a strong light source and illuminates the scenery around a second underwater vehicle that must follow a pre-determined path and acquire video images for scientific purposes.

3. Cooperative autonomous underwater vehicle control: fast acoustic coverage of the seabed. In this important case, two vehicles are required to fly above the seabed at the same or different depths, along parallel paths, and map the seabed using two copies of the same suite of acoustic sensors (e.g. sidescan, mechanically scanned pencil beam, and subbottom profiler). By requesting the two vehicles to traverse identical paths so as to make the acoustic beam coverage overlap on the seabed, large areas can be covered in a fast manner.

Clearly, these Multi-Vehicle Primitives are essentially time-driven (in opposition to event-driven) and involve dynamics that typically occur at faster rates than those of the events associated with the “higher level” Coordination Mission Control System. For example, a set of vehicles may be asked to execute a given MVP by the CMCS. However, as a reaction to the conditions of the environment, the CMCS may wish at some point to invoke a new MPV. It is up to the new MVP supervisor to trigger the set of actions aimed at transitioning between Primitives in a safe manner. In this context, one is led naturally to the need of defining a basic number of MVPs. Among these, the following have been the subject of current intensive research at� ISR/IST: path following, trajectory tracking, combined path following / trajectory tracking, and coordinated path following, as detailed in Section T4 above.

The apparent simplicity of the above examples of Primitives hides the complexity of the plethora of problems that must be solved to fully implement them. In fact, the execution of these Primitives requires that a number of Navigation, Guidance, and Control Systems be in place (on each vehicle) and that the algorithms for coordinated navigation and control yield adequate performance in the face of environment disturbances and communication failures. The importance of the latter can hardly be overemphasized, given the extremely hard constraints imposed by the marine environment and the sheer lack of high bandwidth, reliable communication links underwater.

With a view towards developing practical solutions for the implementation of Multi-Vehicle Primitives, we have been exploring the use of Petri Nets and developing hardware architectures for distributed real-time control of ocean robotic vehicles. Here, we are tacitly assuming that the “rates” of the time-driven and event-driven systems are drastically different. The work builds on previous development efforts that led to CORAL and on the work of former MSc student Rudolfo Oliveira (under the supervision of Prof. Carlos Silvestre) who solidified the extension of CORAL to deal with multiple vehicle operation. In 2005, the focus was on the completion of a real-time distributed architecture that will give support to the implementation of a Coordinated Mission Control System for the vehicles that are property of ISR/IST. This work led to the MSc thesis of� Research Assistant Jo�o Alves on Real Time Architectures for Autonomous Vehicles [TR15].

 3. RESEARCH ACTIVITIES

3.1. RESEARCH PROJECTS

Project name: Robotic Underwater Vehicles and Marine Animals Tracking Systems – RUMOS

Project leader within ISR: Prof. Paulo Oliveira (IST/ISR)

Project description: The main purpose of the project is the development of a set of devices and methodologies for precise estimation of trajectories of underwater robotic vehicles (autonomous and remotely operated) and marine animals.

In order to overcome the problems that occur due to the highly noise environment and the presence of a multitude of disturbances a number of efforts must be set forth to overcome the problem at hand.

The topics include:

i) Mission scenario characterization;

ii) Development of high gain power amplifiers for acoustic wave generation;

iii) Development of very-low noise acoustic data acquisition systems;

iv) Study and development of accurate navigation algorithms for sensor fusion;

v) Development of post-processing techniques for very precise trajectories estimation;

vi) Accurate and real-time monitoring of 3D trajectories in selected coastal and oceanic fish species.

Research Areas: Underwater Positioning Systems, Tracking Systems, Sensor Fusion, Behavior and Ecology of fishes.

Laboratories: Dynamical Systems and Ocean Robotics Lab (DSORL)

External Partners: IMAR/ Department of Oceanography and Fisheries, Univ. Azores

Initiated: December 2005

Project name: MAYASub (Development of a Small Miniaturized Autonomous Underwater Vehicles for Scientific and Commercial

Project leader within ISR: Prof. Ant�nio Pascoal (ISR / IST)

Project Coordinator: Prof. Ant�nio Pascoal (ISR / IST)

Project description: The key objective of the project is to develop and demonstrate the performance of a small, modular, autonomous underwater vehicle (AUV) for scientific and commercial applications. Envisioned missions include geological and oceanographic surveys, marine biology studies, marine habitat mapping for environmental management, inspection of harbours and estuaries, and marine pollution assessment, to name but a few. Vehicle miniaturization will be achieved by resorting to small embedded processors, miniaturized sensors, and high performance actuators. Modularity will allow for easy vehicle reconfiguration according to different mission scenarios. Reduced weight will make it possible to launch and retrieve the vehicle by resorting to small ships of opportunity. The ultimate goal of the project is the development (by a Portuguese-Indian consortium) of two copies of a highly reliable mobile platform that will act as a natural extension of its support ship, effectively allowing an operator to probe the surrounding 3D environment from the comfort of his/her lab at sea.

In 2005 the design of the systems for navigation, guidance, and control of the MAYA_type AUU was consolidated. The first tests with the control systems for the vertical and horizontal plane will take place in Goa, India in February-March 2006. At a mechanical/electrical level, the work focused on the study of a safety device for weight release upon vehicle failure detection as well as on the control plane (fins) arrangement for increased maneuvering performance.

.

The MAYA AUV – Mechanical Design of the NIO, India

Research Areas: Marine Vehicle Design, Hydrodynamic Parameter Estimation and Identification, Navigation, Guidance, and Control, Acoustic Marine Sensors, Underwater Positioning and Communications.

Laboratories: Dynamical Systems and Ocean Robotics Lab (DSORL), VISLAB

External Partners: RINAVE (PT), IMAR/DOP/Univ. Azores (PT), National Institute of Oceanography (NIO) , Dona Paula, Goa, India, System Technologies (ST), Ulverston, UK.

Initiated: January 2003

Expected conclusion: July 2007.

Classification: AdI (Ag�ncia de Inova��o).

Documents produced in 2005: [AIJ6], [AIJ9], [IC1], [IC3], [IC4], [IC10], [IC15], [IC18], [TR2], [TR3], [TR4], [TR9], [TR14], [TR15]

Project name: EXtreme ecosystem studies in the deep OCEan: Technological Developments

Project leader within ISR: Prof. Ant�nio Pascoal

Project Coordinator: Dr. Pierre Marie Sarradin, IFREMER, FR

Project description: The aim of this project is the technological development of a specific instrumentation suite allowing the study of natural or accidentally perturbed ecosystems found in the deep ocean. These ecosystems are related to the emission of reduced fluids (cold seeps, hydrothermal vents), peculiar� topographic structures (seamounts, deep corals), massive organic inputs (sunken woods) or to unpredictable events (pollution, earthquakes). Beside their insularity in the abyssal plain, the targeted ecosystems are characterised by patchy faunal distributions, unusual biological productivity, steep chemical and/or physical gradients, high perturbation levels and strong organism/habitat interactions at infra-metric scales. Their reduced size and unique biological composition and functioning make them difficult to study with conventional instrumentations deployed from surface vessels. Their study requires the use of submersibles able to work at reduced scales on the seafloor as well as the development of autonomous instruments for long-term monitoring (seafloor observatories).

The general objective of the EXOCET/D is to develop, implement and test specific instruments aimed at exploring, describing and quantifying biodiversity in deep-sea fragmented habitats and to identify links between community structure and environmental dynamics. Inboard experimental devices will complement the approach, enabling experiments on species physiology. The EXOCET/D working fields include: video and acoustic imagery; in situ analysis of habitat chemical and physical components; quantitative sampling of organisms; in vivo experiments; 4D integration of multidisciplinary data; implementation on European deep-submersibles as well as validation during demonstration actions. The work of IST/ISR focuses on the development of the acoustic systems that are required to acquire acoustic backscattering data obtained with a mechanical scanning pencil beam sonar. The data will be used for remote marine habitat classification. The final system developed by IST/ISR will be installed on-board the VICTOR ROV, property of IFREMER, for inspection of deep water hydrothermal vent communities during a cruise that will take place in August 2006. The figures below illustrate part of the activity developed in the course of the project.

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Fig. B.

������������� ������������� ������������� ������������� ������������� Fig. C

Figure B. Left: view of mechanical scanning sonar: Middle: the sonar installed underwater; Right: organisms (algae) to be identified remotely.

Figure C. Left: sonar image obtained underwater. The “image” of the organisms on the seafloor is visible; Right: data acquired showing the backscatter data. The second sequence of impulses represents “true” backscatter.

Research Areas:� Acoustic data acquisition and processing, real time-systems, navigation.

Laboratories: DSORLab

External Partners: IFREMER (FR), IMAR/DOP/Univ Azores (PT), AWI (GER), UPMC (FR), CNRS (FR), Cardiff University (UK), Heriot-Watt Univ. (UK), U. Algarve (PT), Univ. Bremen (GER), SeeByte (UK), Systea (IT), Capsum Gmbh (GER), and KC-Denmark (DK)

Initiated: January 1, 2004

Expected conclusion: December 31, 2006

Classification: EC funded project, 6th Framework Programme.

Documents produced in 2004: [TR11], [TR12], [TR13]

Project name: MEDIRES

Project leader within ISR: Prof. Carlos Silvestre (ISR / IST)

Project Coordinator: Dr. Jo�o Alfredo Santos (LNEC)

Project description: The cost of a rubble-mound breakwater, its expected behaviour, as well as the consequences of its failure, do justify the existence of a monitoring programme which helps in the decision making process relative to the timing of the maintenance, or even repair, works. However, the continuous monitoring of the status of any given breakwater stretch is not yet feasible. That is why the most common procedure consists of the periodic inspection of these structures.� The goals of the MEDIRES project are twofold:

I- To use the latest technological breakthroughs in positioning, navigation and control of surface autonomous vehicles to develop new techniques for accurate and efficient inspection of the geometry of semi-submerged structures with application to rubble mound breakwaters. This activity will end up with the development of a tool, named IRIS, for high accuracy surveying of both the above water and submerged parts of the armour layer of rubble-mound breakwaters (or semi-submerged structures, in general).� This tool that can be used in autonomous mode or equip an Autonomous Surface Craft to produce tri- dimensional surveys with the spatial regularity required to this kind of structures;

II- To condense the large volume of data from the periodic inspections into a small set of parameters that enables the characterization of the structure’s status and evolution. The definition of the parameters thresholds, needed for the structure’s diagnosis, will be based on LNEC’s past experience as well as on results from scale model tests.

The tool (IRIS) will be designed to equip the autonomous catamaran DELFIMx. Within the framework of this project, accurate path following control and navigation systems will be developed in order to guarantee the repeatability of the maneuvers so as to ensure the quality of the survey data sets obtained. Nevertheless, the IRIS can be used in standalone mode without the autonomous vehicle.

The autonomous catamaran, named DELFIMx, is capable of following pre-assigned trajectories with a high level of accuracy. It is equipped with two back electrical thrusters and can travel at a maximum speed of 5 knots. In order to determine its position and speed it uses differential GPS and an attitude reference unit. Using the information available from its motion sensor suite the catamaran DELFIMx computes its actual position and orientation and respective velocities.A real time computer network developed at the Institute for Systems and Robotics is used in the autonomous vehicle DELFIMx. This network was specially designed for multi-vehicle robotic applications, uses wireless modems, and implements TDMA (Time Division Multiple Access). The network will effectively allow an operator to supervise the IRIS tool during the survey. Figure 2 depicts the concept of the Catamaran DELFIMx equipped with the IRIS, during a typical breakwater survey. The figure shows how the tool is placed in the Catamaran and illustrates how the 2D laser range finder and the sonar profiler can be used in a breakwater survey mission.

The inspection techniques to develop within the framework of this project will be tested in Sines’ West breakwater and in the breakwater of the Avil�s port (in Ast�rias, Spain). Several surveys will be conducted during the project, to identify and tune the algorithms and tools for online data set acquisition and off-line processing.

Figure 1�������������������������������������������������������� Figure 2

So far, two surveys of the armour layer of Sines west breakwater were carried out with IRIS. The first one took place on June 2003, while the second took place in June 2004. In the 2003 survey, the first time ever IRIS was used, it become obvious that at least two not so small details had been overlooked that far.The first one was related to the measurement of the Earth magnetic field that was fundamental to find the IRIS’ heading. In order to get heavier Antifer cubes at the head of the breakwater, hematite, an iron ore, was included in the concrete aggregates. That is the cause for the darkish area at the breakwater head in the pictures of Sines west breakwater. This means that the heading measurements from the electronic compass were disturbed by the structure. This problem lead to the development of the procedure to estimate the IRIS heading that is now implemented: two GPS receivers, one at the fore and another at the aft of the support vessel give the vessel’s heading and IRIS heading.

a) ������������� b)

Figure 3. The IRIS high accuracy measuring device. a) Detail of the mechanically scanned high aperture sonar profiler; b)View of IRIS installed in the support vessel.

So far, the MEDIRES project produced a pre-prototype of the high-accuracy measuring device that is presented in Figure. 1. It surveys only the submerged part of rubble-mound breakwaters. The figure shows a detail of the mechanically scanned high aperture sonar and the IRIS pre-prototype mounted on the support vessel.

Figure 4 shows that the survey produced by IRIS is quite comprehensive. Instead of an ensemble of surveys from sections along the breakwater, one has a very good scan of the armour layer (in this part of the structure alone 63969 points were surveyed). This large number of surveyed points implies a finer detail in the description of the armour slope, as can be seen in the figure.

a) Previous Survey

b) IRIS Survey

Figure 4. a) Perspective of the surface obtained with the points previously surveyed; b) Perspective of the surface obtained with points surveyed by IRIS.

A key point in that project is the development of IRIS - a measuring device for high accuracy surveys of both the submerged and emerged parts of those structures. The surveys obtained with the pre-prototype of IRIS, which is only able to survey the submerged part of the armour layer showed that a good scan of this part of the structure can be obtained.

Research Areas:� Real Time Architectures, Inertial Navigation, laser and acoutic mapping. Laboratories: DSOR, VISLAB

External Partners: Laborat�rio Nacional de Engenharia Civil, Lisbon, Portugal. Administra��o do Porto de Sines, Sines Portugal. Autoridade do Porto de Avilez, Avilez, Espanha.

Initiated: March 1 2003

Expected conclusion: June 30 2007

Classification: AdI (Ag�ncia de Inova��o).

Documents produced in 2005: [NJ1], [TR13]

Project name: ALTICOPTER

Project leader within ISR: Prof. Carlos Silvestre (ISR / IST)

Project Coordinator: Prof. Carlos Silvestre (ISR / IST)

Project description: Today, some Unmanned Air Vehicles (UAVs) exhibit a high degree of reliability when operating in dynamic and uncertain environments and challenging operation scenarios. Among the many UAV configurations available today, helicopters are one of the most maneuverable and versatile platforms. They can takeoff and land without a runway and can hover in place. These capabilities have brought about the use of unmanned helicopters as highly maneuverable sensing platforms, allowing for the access to remote and confined locations without placing human lives at risk. For these reasons, there is currently great interest in using unmanned robotic helicopters in a wide range of applications that include crop spraying, hazardous spill inspection, fire surveillance, pollution monitoring, overhead power cables inspection, bridge and building construction inspection, etc.

This project focuses on the development of an unmanned robotic helicopter for precise airborne laser altimetry and surveying of disaster scenarios. The resulting system will be used to monitor the evolution of sand dunes and beaches as well as to demonstrate the usefulness of these platforms in disaster scenarios. Motivated by the high accuracy requirements of the envisaged applications as well as by the highly complex, coupled, and unstable dynamics of the helicopter, a whole range of research topics are being addressed within the framework of Alticopter.

������������� - Sensor based control for autonomous vehicles: Development of control laws that can react directly to ������������� sensor data in real time. The control strategies consist of converting the motion control problem into that ������������� of driving to zero a generalized error, defined in a suitable sensor set error space. Within the context of ������������� this topic, a laser based terrain following controller has already been designed and evaluated in ������������� simulation.

������������� - Path following controllers for extended flight envelope maneuvers: Study of control strategies to drive ������������� the helicopter along arbitrary paths in 3D, namely paths that can involve sudden changes on the ������������� platform’s angle of attack (e.g. 0 to 90 degrees). The theoretical tools required to address these problems ������������� borrow from nonlinear scheduling control theory.

������������� - Real-time distributed architectures for mission and vehicle control: Study and development of ������������� architectures to simplify the task of performing the concerted operation of the different systems resident ������������� on board autonomous vehicles.

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Figure 1. Vario Xtreme Helicopter equipped with control electronics. Left) Helicopter ready to takeoff; Right) Detail of the control electronics and motion sensors.

Figure 1 shows the Vario Xtreme model-scale Helicopter during the tests that took place in May 2004. These open loop tests with onboard instrumentation were carried out for acquisition of flight test data needed to calibrate the helicopter dynamic simulator.

An additional helicopter platform, the new Bergen R/C Industrial Twin shown in Figure 2. As shown in the figure, a new reinforced landing gear designed at ISR was fitted to the platform to better accommodate and isolate from vibration all onboard instrumentation. The Bergen Industrial Twin is capable of lifting a 11Kgf payload for one half hour on a tank of gas. The Industrial twin uses a twin cylinder Bergen/Zenoah - 52cc engine, producing about 8 horsepower. A single carb manifold is used for ease of mixture adjustment. A large, high efficiency fan is in place to provide cooling for the engine. Power is transmitted through a heavy duty double clutch and clutchbell to a twin main� gear. A fully hardened 10mm hollow mainshaft turns the all aluminum head and fully ballraced� aluminum blade grips. Symmetrical 810 mm V-Blades provide the lifting power. The Industrial Twin Features an aluminum torgue tube to transmit power to the aluminum tail gearbox with delrin gears and 130 mm tail blades.

Figure 2 Bergen Industrial Twin Helicopter with modified landing gear.

Research Areas: Nonlinear dynamic modeling, Guidance and Control, Inertial Navigation, Laser and Vision Mapping.

Laboratories: DSOR, VISLAB

External Partners: Instituto Geol�gico e Mineiro, Lisbon, Portugal

Initiated: May 1 2002

Conclusion: December 31 2005

Classification: FCT – Sapiens

Documents produced in 2005: [AIJ4], [IC2], [IC5], [IC8], [IC9], [TR5], [TR16]

Project Name: ObservFly

Project Coordinator: Prof. Carlos Silvestre (ISR / IST)

Project description: The primary objective of the ObservFly Project is to equip a large (3.5 m wing span) radio-controlled model airplane, developed by and property of CavadasAeromodelismo, with avionic systems that will be able to autonomously steer the airplane through a series of� predefined smooth trajectories with the goal of recording image data from a wireless camera installed on board. The avionics is vibration isolated from the fuselage using a soft suspension mechanism, which acts as a mechanical low pass filter to provide further attenuation of the aircraft vibration on the electronics. The avionics hardware is built using the low power high performance floating point Texas Digital Signal Processor (DSP) TMS320C33, which is connected to the data acquisition hardware through a dual port RAM expansion board. The onboard distributed architecture is being built around the CAN (Controller Area Network) Industrial Real Time Network. Communication with the ground station is done resorting to a Serial Link Internet Protocol over a wireless modem that allows for transmission of the aircraft status (attitude, linear and angular position, airspeed, etc.) and reception of uplink commands from the ground station in real-time. A simulation model of the Aircraft Dynamics named SimAirDyn, is also being developed and tuned for the ObservFly platform. SimAirDyn is an accurate mathematical model suitable for effective control system design and flight envelope expansion. The Airplane is modeled as a six degrees of freedom rigid body, actuated by forces and moments that are generated at the propeller, fuselage, and wings. The remaining components, namely the landing gear and the antennas, which have a smaller impact on the overall behavior of the aircraft dynamic model, are not included in the simulator and will be treated as disturbance by the control system.� The Inertial Navigation System onboard the platform will use the algorithms developed within the scope of the ASAINS project The navigation information together with the airspeed are transmitted through the downlink at a transmission rate of 1 Hz. From the Guidance and Control System point of view the Aircraft operation modes relevant for the project are autonomous takeoff, accurate stationary flight, and landing. The first two flight conditions involve controlling the platform using the information provided by the navigation system. The last and critical flight condition is the automatic landing. The controller for automatic landing will be developed using a sensor based approach. To improve the airborne data acquisition quality, special emphasis will be placed on developing 3-D guidance and control systems for accurate path following and trajectory tracking.

Aircraft Characteristics: The Aircraft is capable of lifting a 11Kgf payload for two hours on a tank of gas, The Wingspan is 3.5m and the length is 1.8m and has a takeoff distance half load of 50m. It uses a one cylinder two stroke- 60cc engine, producing about 8 horsepower.

Classification: Internal Project

3.2. POST-DOCS ACTIVITIES REPORT

3.3. THESES

3.3.1. Theses concluded

M. Sc. THESES

Theses Submitted

Research Area:� Real Time Systems

Title: Real Time Architectures for Autonomous Vehicles

Master Student:� Jo�o Alves

Advisor: Carlos Silvestre

Initiated: October 2002

Conclusion: 2005

Current Status: submitted

Abstract:

This thesis addresses some of the problems related with the conception and implementation of real-time distributed systems. The hardware architecture on which the real-time system was developed is presented and the different hardware modules and solutions for communication support are described. An overview of the CAN bus is presented and a higher layer protocol to work over the CAN bus limitations imposed by the packet size is proposed, aiming to expand the protocol's ability to handle long messages. An addressing scheme over CAN is implemented in order to tackle the problem of routing with other heterogeneous network interfaces. In addition, some solutions to incorporate different network topologies with CAN are presented. The reliable communication problem in distributed systems with reduced computational resources is addressed and a UDP based solution is the proposed and implemented. After the presentation of the different communication solutions, a flexible and modular network architecture for distributed systems integration is presented. The need for a global time base in distributed systems is introduced and the problem of clock synchronization on distributed architectures is studied. A software architecture for modular support in distributed real-time systems is proposed and it's logical and timing correctness analyzed. Finally as an example of application of the proposed architecture to the control of the autonomous underwater vehicle Infante, developed at Instituto Superior T�cnico, is presented.

Keywords: Real-time systems; CAN bus; Distributed systems; Network architectures; Protocols; Autonomous vehicles.

Members of the thesis committee:

Jo�o Pereira, Assistant Professor, Instituto Superior T�cnico, Portugal

Ant�nio Ruano, Associate Professor, Universidade do Algarve, Portugal

Carlos Silvestre, Assistant Professor, Instituto Superior T�cnico, Portugal

Documents produced in 2005: [NJ1], [TR15]

Theses Defended

Research Area: Control of Autonomous Vehicles

Title: Terrain Tracking Control Strategies for Autonomous Vehicles with application to Unmanned Helicopters

Master Student: Nuno Paulino

Advisor: Carlos Silvestre

Initiated: April 2003

Concluded: March 2005

Grant: FCT/Alticopter Project

Abstract:

This thesis addresses the problem of terrain following by a model-scale helicopter equipped with a Laser Range Scanner that provides information about the terrain profile ahead the vehicle. The methodology used to solve the terrain following control problem amounts to convert it into it as a discrete time path following control problem where state space model of the plant is augmented with the terrain preview data.

The path following control problem is then converted into an equivalent regulation problem of a conveniently defined generalized error space. Using the fact that the generalized error dynamics is time invariant along straight lines, the error dynamic is linearized and discretized, and the problem is then posed and solved under the scope of gain-scheduling control theory. The synthesis problem of each linear controller associated to each state space operating region is stated as a discrete time state feedback H2 control problem and solved using Linear Matrix Inequalities. The feedforward gain matrix is then computed using a proposed sub-optimal technique that avoids solving Linear Matrix Inequalities involving a large number of unknowns. This methodology naturally leads to an integrated guidance and control system design technique for terrain following, where the stability around equilibrium or trimming trajectories contained in the several pre-defined operating regions is guaranteed. The thesis introduces a technique to build the reference path given the terrain profile information provided by the sensor where the characteristics of the future reference are transformed into a deterministic disturbance - preview disturbance - to be used in the feed-forward part of the preview controller. The overall performance of the terrain following integrated guidance and control system is evaluated in simulation with a full non-linear model of a model-scale helicopter.

Members of the thesis committee:

Maria Isabel Ribeiro, Full Professor, Instituto Superior T�cnico, Portugal

Jos� S� da Costa, Full Professor, Instituto Superior T�cnico, Portugal

An�bal Ollero, Full Professor, Instituto Superior T�cnico, Portugal

Carlos Silvestre, Assistant Professor, Instituto Superior T�cnico, Portugal

Documents produced in 2005: [NJ1], [TR15]

3.3.2. Theses in Progress

DOCTORAL THESES

Research Area:� Guidance and Control of Dynamical Systems

Title: Sensor-Based Guidance and Control of Robotic Vehicles

Doctoral� Student:� Rita Cunha

Advisor:� Carlos Silvestre

Initiated: 2001

Expected Conclusion: 2006

Current Status: On-going

Grant: FCT Graduate Scholarship

Documents produced in 2005: [AIJ4], [IC5], [TR5]

Research Area:� Control and Navigation of Autonomous Vehicles

Title:� Integrated Design of Navigation and Control Systems for Autonomous Vehicles

Doctoral� Student:� Jos� Vasconcelos

Advisor: Carlos Silvestre and Paulo Oliveira

Initiated: 2004

Expected Conclusion: 2008

Current Status: On-going

Grant: FCT Graduate Scholarship

Documents produced in 2005: [IC2], [IC9]

Research Area: Control Theory

Title: Coordinated Path Following Control of Multiple Autonomous Vehicles

Doctoral� Student: Reza Ghabcheloo

Advisor:� Ant�nio Pascoal / Carlos Silvestre

Initiated: 2002

Expected Conclusion:� 2006

Current Status: On-going

Grant: FCT Graduate Scholarship

Documents produced in 2005: [AIJ5], [AIJ8], [IC7], [IC10], [IC11], [TR7], [TR14]

Research Area: Navigation

Title:� Landmark-Based Navigation of Autonomous Underwater Vehicles (AUVs) using Bathymetric and

Geomagnetic Information.

Doctoral� Student:� Francisco Curado Teixeira

Advisor: Ant�nio Pascoal (IST) / Hip�lito Monteiro (Geological Survey of Portugal – IGM)

Initiated: 2001

Expected Conclusion:� 2006

Current Status: On-going

Grant: FCT Graduate Scholarship

Documents produced in 2005: [IC18], [TR9], [TR10]

Research Area:� Control Theory

Title:� Robust Adaptive MIMO Control using Multiple-Model Hypothesis Testing and

Mixed Mu-Synthesis

Doctoral� Student: Sajjad Fekri Asl

Advisor:� Michael Athans / Ant�nio Pascoal

Initiated: 2002

Expected Conclusion:� 2006

Current Status: On-going

Grant: FCT Graduate Scholarship

Documents produced in 2005: [AIJ7], [IC16], [TR6]

Research Area: Navigation and Positioning Systems

Title: Navigation and Positioning Systems for Underwater Robots using Nonlinear Estimation� Techniques

Doctoral� Student:� Alex Alcocer Pe�as

Advisor:� Paulo Oliveira / Ant�nio Pascoal

Initiated: 2004

Expected Conclusion:� 2008

Current Status: On-going

Grant: FCT Graduate Scholarship

Documents produced in 2005: [AIJ6], [TR2], [TR3], [TR4]

Research Area:� Guidance and Control of Dynamic Systems

Title: Terrain Avoidance Control for Robotic Helicopters

Doctoral� Student: Bruno Guerreiro

Advisor:� Carlos Silvestre

Initiated: 2005

Expected Conclusion:� 2009

Current Status: research in progress

Documents produced in 2005

M. Sc. THESES

Research Area: Real Time Navigation Systems

Title: Real Time Architectures for Inertial Navigation Systems with application to Autonomous Vehicles.

Master Student: Bruno Cardeira

Advisor: Carlos Silvestre/Paulo Oliveira

Initiated: 2004

Expected conclusion: November 2006

Current Status: research in progress

Grant: Project MEDIRES, AdI

Documents produced in 2005

Research Area: Control of Autonomous Vehicles Systems

Title: Laser Based Obstacle Avoidance Guidance and Control Techniques for

Unmanned Catamarans.

Master Student: Pedro Gomes

Advisor: Carlos Silvestre/Antonio Pascoal

Initiated: November 2005

Expected conclusion: June 2007

Current Status: research in progress

Documents produced in 2005

3.4. ADVANCED TRAINING

������������� 3.4.1. Courses

Paulo Oliveira

������������� DYNAMIC STOCHASTIC ESTIMATION, PREDICTION, AND SMOOTHING, a one semester ������������� doctoral ������������� level course taught at IST, previously taught together with Prof. Michael Athans.

Carlos Silvestre

������������� DESIGN OF ROBUST MULTIVARIABLE FEEDBACK CONTROL SYSTEMS, a one semester ������������� doctoral level course taught together with Prof. Michael Athans.

    Pedro Aguiar

������������� NONLINEAR SYSTEMS, a one semester doctoral level course taught at IST.

3.4.2. Seminars

Seminars outside ISR:

Paulo Oliveira

“Tecnologias Aeroespaciais, Oce�nicas e Ambiente,” Dia de Reflex�o Estrat�gica do DEEC, co-author Prof. Jo�o Paulo Teixeira, Tagus Park, July 2005.

Carlos Silvestre

Mission and Vehicle Control of Marine and Aerial Vehicles at Institute for Systems and Robotics, ������������� Computer ���� Engineering Department University of California at Santa Cruz, California, USA, 19 of Agosto, 2005.

A. Pedro Aguiar

������������� �������������

Performance Limitations in Reference-Tracking and Path-Following, Workshop on “New Developments in Control Performance Limitation Research: A Tale in the Network Age” for the ������������� 44th Conference on Decision and Control in Seville, (CDC'05), Spain, December 2005.

ISR Regular seminars:

SEMINAR MEETINGS OF THE DSORL (Dynamical System and Ocean Robotics Laboratory) were held periodically during the year of 2005

ISR SEMINARS

“From Discrete Specifications to Embedded Control Software,“

Paulo Tabuada, University of Notre Dame, USA

January 2005

“Coordinated Path Following Under Communication Constraints – Part I,”

Reza Ghabcheloo, PhD. Student ISR

February 2005

“AUV Terrain Aided Navigation using Particle Filters,”

Francisco Curado, PhD. Student ISR

February 2005

“Projetos em Desenvolvimento no GATI - Grupo de Automa��o e Tecnologias da Informa��o,”

Luiz Edival de Souza e Leonardo de Mello Hon�rio, Universidade Federal de Itajub�, Brasil

February 2005

“Coordinated Path Following Under Communication Constraints – Part II,”

Reza Ghabcheloo, PhD Student, ISR

March 2005

“The Fundamental Matrix for Dipotric Cameras with Radial Distortion. Application on the Calibration of Wide Area Camera Networks,”

Jo�o Pedro Barreto, Faculdade de Ci�ncias e Tecnologia, Universidade de Coimbra

March 2005

“Unmmaned Aerial Vehicles at Seville Universit,”

Anibal Ollero, Seville University, Spain

March 2005

“Partition-Distance Methods for Image Segmentation,”

Jaime Cardoso, INESC Porto

April 2005

“Guidance, Navigation and Control of Formation Flying Spacecraft� Part I - Mission and GC Algorithm,“

Dan Dumitriu and Pedro Lima, ISR

April 2005

“Guidance, Navigation and Control of Formation Flying Spacecraft� Part II - Navigation Algorithm,“

S�nia Marques, PhD Student, ISR

May 2005

“Internet Trafic : Long Memory and multifractal ? Application to anomaly detection,”

Patrice Abry, CNRS, ENS-Lyon, France

May 2005

“R&D at IdMind - Engenharia de Sistemas, Lda ,“

Jo�o Crist�v�o, IdMind

May 2005

“Know thy self. Modeling the basic cognitive properties of the immune system,”

Jorge Carneiro, Instituto Gulbenkian de Ci�ncia

June 2005

“Multivehicle Mapping in Large Environments,”

Jos� Neira , Departamento de Informatica e Ingenieria de Sistemas, University of Zaragoza

June 2005

“An Information Theoretic Approach to the Fundamental Limitations of Feedback,”

Nuno Martins, LIDS MIT

June 2005

“Compressed Domain Video Processing with Applications to Surveillance,”

Miguel Tavares Coimbra, IEETA - Universidade de Aveiro.

July 2005

“Sistemas Aut�nomos: Investiga��o em Curso no ISEP,"

Eduardo Silva, LSA/ISEP

September 2005

“Positive 1D and 2D systems – realization problem,”

Tadeusz Kaczorek, Warsaw University of Technology,

September 2005

“Terrain Following Controller for Affne Parameter-Dependent Systems: An Application to Model-Scale Helicopters,”

Nuno Paulino, MSc., ISR

November 2005

“End-to-End Optimal Algorithms for Integrated QoS, Traffic Engineering, and Failure Recovery, “

Constantino Lagoa, Associate Professor, Pennsylvania State University

November 2005

“On the Design of Optimal and Robust Supervisors for Deterministic Finite State Automata,”

Constantino Lagoa, Associate Professor, Pennsylvania State University

December 2005

3.4.3. Reading Groups

3.4.4. Visits Abroad

�������������

Ant�nio Pascoal

Invited Scientist, National Institute of Oceanography, Dona Paula, Goa, India, January 2005 in the scope of the MAYA-Sub project of the AdI and the joint Indian-Portuguese Cooperation Program

Luis Sebasti�o

�������������

Invited Researcher, National Institute of Oceanography, Dona Paula, Goa, India, January 2005 in ������������� the scope of the MAYA-Sub project of the AdI and the joint Indian-Portuguese Cooperation ������������� Program

3.4.5. Supervision of Students enrolled in Foreign Universities

�������������

Ant�nio Pascoal

Co-advisor, Danilo de Carvalho, PhD student enrolled at UFES (Federal University of Esp�rito Santo), Vit�ria, Esp�rito Santos, Brasil. Tema geral da tese de doutoramento: Path Following and Coordinated Path Following of Multiple Fully Actuated Marine Vehicles.

3.5. CONGRESSES, MEETINGS and PRESENTATIONS

3.5.1. Invited Talks

Carlos Silvestre - Mission and Vehicle Control of Marine and Aerial Vehicles, Keynote Speaker, MarTech05 Primer Congreso Internacional de Tecnolog�a Marina, organized by the Universidade Polit�cnica da Catalunha, Vilanova i la Geltr� – Vilanova, Catalonia, Spain,� 17 to 18 of Novembre, 2005,

Carlos Silvestre - Autonomous Helicopters for Inspection and Observation Tasks: the ALTICOPTER project, Workshop on the Employment of Unmanned Vehicles in the Naval Operations, Centro de Instru��o de T�ctica Naval (CITAN), Alfeite, Portugal, 20 -22 of September, 2005.

Ant�nio Pascoal - “Vehicle and Mission Control of Single and Multiple Autonomous Marine Robots: The Present and a Vision of the Future”. Plenary Talk, International Workshop on Underwater Robotics, (IWUR2005), Genova, Italy, Nov. 11th, 2005.

Ant�nio Pascoal - “Robots of the Abyss”. Invited Talk, Festival of Science, School of Robotics, Genova, Italy, November 9, 2005.

Ant�nio Pascoal - “Vehicle and Mission Control of Single and Multiple Autonomous Marine Robots”. Invited Talk, UUV Showcase Conference, Southampton, UK, 29 September 2005

Ant�nio Pascoal - Theory and Practice of Marine Robotics in Portugal”. Invited Talk, Research and Technology Initiatives in Portugal, CITAN, Portuguese Navy, Sept. 20, 2005.

Ant�nio Pascoal - “Robotics for Ocean Exploration”. Invited Talk, VII Summer Course of Ericeira, Instituto de Cultura Europeia e Atl�ntica (ICEA), Ericeira, April 9, 2005.

Ant�nio Pascoal - “Marine Robotics: Scientific and Technological Challenges”. Invited Talk, Congress of the Sea, Nazar�, April 1, 2005.

3.5.2. Participations

Paulo Oliveira

44th IEEE Conference on Decision and Control/European Control Conference, Seville, Spain, ������������� December 2005.

������������� 4�s Jornadas Portuguesas de Engenharia Costeira e Portu�ria, Angra do Hero�smo, October 2005.

������������� AIAA Guidance, Navigation, and Control Conference, San Francisco, USA, August 2005.

������������� 16th IFAC World Congress, Prague,� Czech Rep., July 2005.

������������� 2nd Iberian Conference on Pattern Recognition and Image Analysis, Estoril, Portugal, June 2005.

Carlos Silvestre

IFAC 16th World Congress 2005, Prague Czech Republic, June 2005.

AIAA GNC 2005, San Francisco USA, August 2005.

44th IEEE Conference on Decision and Control/European Control Conference, Seville,

Spain, December 2005.

Rita Cunha

IFAC 16th World Congress 2005, Prague Czech Republic, June 2005.

Jos� Vasconcelos

AIAA GNC 2005, San Francisco USA, August 2005.

A. Pedro Aguiar

IEEE Conference on Decision and Control, Seville, Spain, December 2005.

IFAC 16th World Congress 2005, Prague Czech Republic, June 2005.

A. Pascoal

International Workshop on Underwater Robotics, Genova, Italy, 9-11 November, 2005.

IEEE Conference on Decision and Control, Seville, Spain, December 2005.

IFAC 16th World Congress 2005, Prague Czech Republic, June 2005.

R. Ghabcheloo

IEEE Conference on Decision and Control, Seville, Spain, December 2005.

12th International Conference on Advanced Robotics, ICAR 2005, Seattle, Washington, USA, 18-20 July, 2005.

3.6 SERVICIES ACTIVITIES

3.6.1. Editorial Boards

3.6.2. Advisory Boards

A. Pascoal

Consultant, Program on Platforms for Marine Monitoring, Desk-Study, Marine Institute, Galway, Ireland.

Portuguese Delegate to EurOcean: an Internet Portal for Marine Science and Technology in Europe, FCT,

Lisbon, Portugal.

Portuguese Delegate to the Marine Board of the European Science Foundation

Member, Consulting Committee of the Strategic Commission for the Oceans, in charge of submitting to the Adjunct Minister of the Prime Minister of Portugal an integrated document that is as a road map for future ������������� activities - at a national scale - on a wide range of ocean related issues, including marine science and ������������� technology.

Portuguese Representative to EurOcean: an Internet Portal for Marine Science and Technology in Europe, ������������� FCT, Lisbon, Portugal.

3.6.3. Program and Technical Committees

Paulo Oliveira

Member of the Programme Committee of the “Encontro Nacional de Rob�tica,” Coimbra, April 2005.

A. Pedro Aguiar

Member, International Federation of Automatic Control (IFAC), Technical Committee on Intelligent Autonomous Vehicles.

Ant�nio Pascoal�

Vice-Chair, International Federation of Automatic Control (IFAC), Technical Committee on Marine Applications.

Member, International Federation of Automatic Control (IFAC), Technical Committee on Intelligent Autonomous Vehicles.

Member, International Program Committee, 3th IEEE Mediterranean Conference on Control and Automation (MED-05), Cyprus.

Member, International Program Committee, 2005 IEEE International Conference on Intelligent Robots and Systems (IROS�2005), Canada.

Member, International Program Committee, "International Workshop on Underwater Robotics for Sustainable Management of Marine Ecosystems and Environmental Monitoring", Italy.

3.6.4. Chairperson

Paulo Oliveira

Session Chair, IEEE Control and ������������� Decision Conference/European Control Conference, Seville, Spain, December 2005. Session Title: Aerospace and Vehicle Control

Carlos Silvestre

Session Chair, IFAC 16th World Congress 2005, Prague Czech Republic, June 2005. Session Title: Intelligent Vehicle Control (Oral Session).

Ant�nio Pascoal

Session Chair, IFAC 16th World Congress 2005, Prague Czech Republic, June 2005. Session Title: Multiple Vehicles II.

Session Chair, IEEE Control and ������������� Decison Conference/European Control Conference, Seville, Spain, December 2005. Session Title: Control of Mechanical Systems I .

Session Chair, International Workshop on Underwater Robotics, Genova, Italy, 9-11 November, 2005. Session Title: Cooperation and Control I.

3.6.5. Reviewers

Paulo Oliveira

������������� Conferences

������������� IEEE Control and Decision Conference/European Control Conference, December 2005.

������������� Iberian Conference on Pattern Recognition and Image Analysis, June 2005.

������������� IFAC World Congress, July 2005.

������������� “Encontro Nacional de Rob�tica,” April 2005.

������������� Journals

������������� IEEE Transactions on Oceanic Engineering, November 2005.

Carlos Silvestre

������������� Journals

������������� IEEE Robotics and Automation Magazine, Institute of Electrical and Electronic Engineers.

������������� IEEE Transactions on Control Systems Technology

������������� International Jornal of Systems Science

�������������

������������� Conferences

������������� American Control Conference, ACC2005, Portland Oregon USA, June 2005

������������� 44th IEEE Conference on Decision and Control and European Control Conference ECC 2005, ������������� Seville Spain, December 2005.

������������� International Conference on Robotics and Automation, Barcelona, Spain, April, 2005

������������� 16TH IFAC World Congress, Prague Czech Republic, July, 2005

������������� IEEE/RSJ International Conference on Intelligent Robots and Systems, Canada, August, 2005

������������� 2005 International Symposium on Intelligent Control and 13th Mediterranean Conference on ������������� Control and Automation, Limassol, Cyprus, June 2005.

������������� A. Pedro Aguiar

������������� Journals

IEEE Transactions on Automatic Control.

IEEE Transactions on Robotics.

Automatica.

������������� Conferences

44th IEEE Conference on Decision and Control and European Control.

American Control Conference, ACC2005.

16th IFAC World Congress

ASME International Mechanical Engineering Congress and Exposition.

Ant�nio Pascoal

������������� Journals

������������� International Journal of Systems Science

������������� Journal of Applied Mathematics

������������� IEEE Transactions on Automatic Control

������������� Journal of Guidance, Control, and Dynamics

������������� Automatica

������������� IEEE Transactions on Control Systems Technology.

������������� Conferences

������������� American Control Conference, ACC2005

������������� IEEE Conference on Decision and Control, CDC2005

������������� 5th International Conference on Technology and Automation - ICTA'05�

������������� 16TH IFAC World Congress

������������� IROS 2005: IEEE/RSJ International Conference on Intelligent Robots and Systems

������������� MED2005 – Mediterranean Control Conference

3.6.6. Other Activities

Paulo Oliveira

Member of the Jury to select the Portuguese representatives for the Schneider Electric Expo Inici@tive 2005, Seville, Spain, May 2005.

A. Pedro Aguiar

Organizer of the workshop on “New Developments in Control Performance Limitation Research: A Tale in the Network Age'” for the 44th Conference on Decision and Control in Seville, (CDC'05), Spain, December 2005 (with Jie Chen, Rick Middleton, and Li Qiu).

A. Pascoal

Member, Workgroup on Research Vessels of the Intersectorial Oceanographic Mission / Ministry of Science and Technology, Portugal. Objective of the Workgroup: to assess the state of the scientific fleet and to define guidelines for its expansion and efficient utilization by the scientific community at large.

Member, Workgroup on Deep Sea Research of the Intersectorial Oceanographic Mission / FCT, Portugal. Objective of the Workgroup: to foster the development of deep sea marine science and technologies.

Member, SCOR (Scientific Committee on Ocean Research)� Panel on New Technologies for Observing

Marine Life, the Sloan Foundation, USA.

Member, Global Ocean Observation System (GOOS) Working Group, Intersectorial Oceanographic Comission, FCT, Lisbon, Portugal.

3.7. ACADEMIC ACTIVITIES

Paulo Oliveira

Member of the Jury of the M.Sc. Thesis of Carlos Bastos, “Controlo de uma Aeronave Robotizada no Solo,” IST, June 2005.

Ant�nio Pascoal

Member of the PhD jury of Paulo Alexandre da Silva Felisberto, “Data Assimiliation with Applications to Ocean Acoustic Tomography,” University of the Algarve, February 2005.

3.8. VISITS TO ISR

3.8.1 Distinguished Visitors

1. Under the Indo-Portuguese Cooperation Program in Science & Technology, and in the context of the bi-lateral project on the Development of a small Autonomous Underwater Vehicle within that program, the following four scientists

������������� R. Madan

������������� E. Desa

������������� P. Maurya

������������� G. Navelkar

with the Marine instrumentation Division of the National Institute of Oceanography� (NIO), Dona Paula, Goa, India visited the Institute of Systems and Robotics (ISR) for a period of 18 days, during the year of 2005. This was the third formal visit from NIO scientists under the Indo-Portuguese S&T program sponsored by GRICES Portugal The objectives of the visit were to:

1) Exchange notes and design ideas on the mechanical and electrical hardware of the two small AUVs under development at NIO and IST/ISR in the scope of the MAYA-PT project of the AdI and the MAYA-IN project of the Indian Ministry for Ocean Development.

2) To discuss topics related to the design and implementation of the systems for vehicle navigation, guidance, and control.

3) To prepare a series of tests that will take place in Goa, India, in February-March 2006.

2. Prof. Constantino Lagoa, Pennsylvania State University, USA, from October-December 2005, during his sabbatical leave. He carried our� research on System Identification and Nonlinear Control

������������� �

3.8.1 Other visits

3.9. SPECIAL EVENTS

3.10. AWARDS

3.11. PUBLICATIONS

A) M.Sc. Theses

[MT1] - Nuno Paulino, “Terrain Tracking Control Strategies for Autonomous Vehicles with Applications to Unmanned Helicopters,” Instituto Superior T�cnico, March 2005, Portugal.

B) Ph.D. Theses

C) Books

D) Books (as Editors)

E) Chapters In Books

�������������

Accepted for publication.

[CB1] - A. Pascoal, C. Silvestre , P. Oliveira. “Vehicle and Mission Control of Single and Multiple Autonomous Marine Robots,” Advances in Unmanned Marine Vehicles (Editor: G. Roberts and R. Sutton). To appear in 2006.

F) In International Journals

Published

[IJ1] – A. Aguiar, Jo�o P. Hespanha, and Petar Kokotović, “Path-Following for Non-Minimum Phase Systems Removes Performance Limitations”, IEEE Transactions on Automatic Control, Vol. 50, No. 2, Feb. 2005, pp. 234-239.

[IJ2] –F. Cardigos, A. Cola�o,� P.R. Dando, S. �vila, P.-M. Sarradin d, F. Tempera, P. Conceic�o, A. Pascoal, R. Serr�o Santos, “Shallow water hydrothermal vent field fluids and communities of the D. Jo�o de Castro Seamount (Azores),” Chemical Geology, Elsevier, 224 (2005), pp. 153-168.

Accepted for Publication

[AIJ1] - A. Pedro Aguiar and Jo�o P. Hespanha, “Minimum-Energy State Estimation for Systems with Perspective Outputs”, Accepted for publication in the IEEE Transactions on Automatic Control.

[AIJ2] - A. Pedro Aguiar and Jo�o P. Hespanha, “Trajectory-Tracking and Path-Following of Underactuated Autonomous Vehicles with Parametric Modeling Uncertainty”, Accepted for publication in the IEEE Transactions on Automatic Control.

[AIJ3] - A. Pedro Aguiar, Jo�o P. Hespanha, and Petar Kokotović, “Performance Limitations in Reference-Tracking and Path-Following for Nonlinear Systems”, Accepted for publication in Automatica.

[AIJ4] - Paulino, N., Silvestre, C., and Cunha, R., “Affine Parameter-Dependent Preview Control for Rotorcraft Terrain Following Flight”, Accepted for publication in the AIAA Journal of Guidance, Control, and Dynamics, 2006.

[AIJ5] - R. Ghabcheloo, A. Pascoal, C. Silvestre , I. Kaminer, “Coordinated Path Following Control of Multiple Wheeled Robots using Linearization Techniques,” Accepted for publication in the International Journal of Systems Science, , 2006.

[AIJ6] - A. Alcocer, P. Oliveira, A. Pascoal, “Study and Implementation of a GIB-Based Underwater Positioning System,” Accepted for publication in the IFAC Journal Control Engineering Practice, 2006.

[AIJ7] - Sajjad Fekri, Michael Athans, Antonio Pascoal, “Issues, Progress and New Results in Robust Adaptive Control,” Accepted for publication in the International Journal on Adaptive Control and Signal Processing, 2006.

[AIJ8] - R. Ghabcheloo, A. Pascoal, C. Silvestre, I. Kaminer, “Nonlinear Coordinated Path Following Control of Multiple Wheeled Robots with Bidirectional Communication Constraints,” Accepted for publication in the International Journal of Adaptive Control and Signal Processing, 2006.

[AIJ9] - L. Lapierre, D. Soetanto, A. Pascoal, “ Nonsingular Path Following Control of a Unicycle in the Presence of Parametric Modeling Ucertainties”, Accepted for publication in the International Journal of Robust and Nonlinear Control, 2006.

G) In International Conferences

[IC1] - Oliveira, P., “MMAE Terrain Reference Navigation for Underwater Vehicles using Eigen Analysis,” 44th IEEE Conference on Decision and Control and European Control Conference ECC 2005,� Seville, Spain, December 2005.

[IC2] - Vasconcelos J.F., Oliveira, P., and Silvestre C., “Inertial Navigation System Aided by GPS and Selective Frequency Contents of Vector Measurements,” AIAA Guidance, Navigation, and Control Conference and Exhibit, San Francisco, USA, August 2005.

[IC3] - Oliveira P., “Terrain Based Navigation Tools for Underwater Vehicles using Eigen Analysis,“ 16th IFAC World Congress, PDF file, Prague, Czech Rep., July 2005.

[IC4] - Oliveira P., “PCA Positioning Sensor Characterization for Terrain Based Navigation of UVs,” 2nd Iberian Conference on Pattern Recognition and Image Analysis, Estoril, June 2005.

[IC5] - R. Cunha, C. Silvestre, “A 3D Path-Following Velocity-Tracking Controller for Autonomous Vehicles”, 16TH IFAC World Congress, Prague Czech Republic,� 4-8 July, 2005.

[IC6] - C. Silvestre, A. Pascoal, “Depth Control of the Infante AUV Using Gain-Scheduled Reduced-Order Output FeedBack”, 16TH IFAC World Congress, Prague Czech Republic,� 4-8 July, 2005.

[IC7] -� Reza Ghabcheloo, Ant�nio Pascoal, Carlos Silvestre, “Nonlinear Coordinated Path Following Control of Multiple Wheeled Robots with Communication Constraints”, 12th International Conference on Advanced Robotics, ICAR 2005, Seattle, Washington, USA, 18-20 July, 2005.

[IC8] - Nuno Paulino, Carlos Silvestre, Rita Cunha, “Terrain Following Controller for Affine Parameter-Dependent Systems: An Application to Model-Scale Helicopters”, AIAA Guidance Navigation and Control Conference, San Francisco, California, USA, 1-18 August 2005.

[IC9] -� J. F. Vasconcelos, P. Oliveira, Carlos Silvestre, “Inertial Navigation System Aided by GPS and Selective Frequency Contents of Vector Measurements”, AIAA Guidance Navigation and Control Conference, San Francisco, California, USA, 15-18 August 2005.

[IC10] -� Reza Ghabcheloo, Antonio Pascoal, Carlos Silvestre, Danilo Carvalho, “Coordinated Motion Control of Multiple Autonomous Underwater Vehicles”, International Workshop on Underwater Robotics for Sustainable Management of Marine Ecosystems and Environmental Monitoring, Genoa, Italy, 9- 11 November, 2005.

[IC11] - Reza Ghabcheloo, Antonio Pascoal, Carlos Silvestre, Isaac Kaminer, “Coordinated Path Following Control of Multiple Wheeled Robots with Directed Communication Links”, 44th IEEE Conference on Decision and Control and European Control Conference, ECC 2005, Seville, Spain, 12-15 December, 2005.

[IC12] -� A. Pedro Aguiar, Jo�o P. Hespanha, and Ant�nio M. Pascoal, “Stability of switched seesaw systems with application to the stabilization of underactuated vehicles”, in Proc. of CDC’05 – 44th IEEE Conference on Decision and Control, Seville, Spain, December 2005.

[IC13] - A. Pedro Aguiar and Jo�o P. Hespanha, “State Estimation for Systems with Implicit Outputs for the Integration of Vision and Inertial Sensors”, in Proc. of CDC’05 – 44th IEEE Conference on Decision and Control, Seville, Spain, December 2005.

[IC14] - A. Pedro Aguiar, Jo�o P. Hespanha, and Petar Kokotović, “Limits of performance in reference tracking and path-following for nonlinear systems”, in Proc. of 16th IFAC World Congress, Prague, Czech Republic, July, 2005

[IC15] - I. Kaminer, A. Pascoal, O. Yakimenko, “Nonlinear Path Following Control of Fully Actuated Marine Vehicles with Parameter Uncertainy,” Proc. 16th IFAC World Congress, Praha, Czech Republic, 2005.

[IC16] - M. Athans, S. Fekri, A. Pascoal, “Issues on robust adaptive feedback control,” Invited Plenary Paper, in Proc. 16th IFAC World Congress, Praha, Czech Republic, pp. 9–39, 2005.

[IC17] - I. Kaminer, O. Yakimenko, A. Pascoal, “Coordinated Payload Delivery using High Glide Parafoil Systems,“ Proc. 18th AIAA Aerodynamic Decelerator Conference and Exhibit,� Munich, 24-26 May, 2005.

[IC18] - F. Teixeira, A. Pascoal, “AUV Terrain Aided Navigation using Particle Filters,“ Proc. International Workshop on Underwater Robotics, Genova, Italy, 9-11 November, 2005.

H) In National Journals

I) In National Conferences

[NJ1] - Santos J., Neves M., Silva L., Silvestre C., Oliveira, P., Sebasti�o L., and Alves J., “Novos Instrumentos para a Inspec��o e Diagn�stico de Quebra-mares de Taludes,” 4�s Jornadas Portuguesas de Engenharia Costeira e Portu�ria, Angra do Hero�smo, October 2005 (in portuguese).

J) In Technical Reports

[TR1] - Paulo Oliveira, “Interpolation of Signals with Missing Data using PCA,” ISR Technical Report, September 2005.

[TR2] - Alex Alcocer, Paulo Oliveira, Ant�nio Pascoal, and Jo�o Xavier, “Maximum Likelihood Attitude and Position Estimation from Pseudo-Range Measurements using Geometric Descent Optimization,” ISR Technical Report, December 2005.

[TR3] - Alex Alcocer, Paulo Oliveira, Ant�nio Pascoal, and Jo�o Xavier, “Estimation of Attitude and Position from Range only Measurements using Geometric Descent Optimization on the Special Euclidean Group,” ISR Technical Report, December 2005.

[TR4] - Alex Alcocer, P. Oliveira, A. Pascoal, “Study and Implementation of a GIB-Based Underwater Positioning System,” ISR Technical Report, July 2005.

[TR5] -� Paulino, N., Silvestre, C., and Cunha, R., “Affine Parameter-Dependent Preview Control for Rotorcraft Terrain Following Flight”, ISR Technical Report, October 2005.

[TR6] - Sajjad Fekri, Michael Athans, Antonio Pascoal, “Issues, Progress and New Results in Robust Adaptive Control,”� ISR Technical Report, November 2005.

[TR7] - R. Ghabcheloo, A. Pascoal, C. Silvestre, I. Kaminer, “Nonlinear Coordinated Path Following Control of Multiple Wheeled Robots with Bidirectional Communication Constraints,” ISR Technical Report, November 2005.

[TR8] - L. Lapierre, D. Soetanto, A. Pascoal, “ Nonsingular Path Following Control of a Unicycle in the Presence of Parametric Modeling Ucertainties”, ISR Technical Report, October 2005.

[TR9] - F. Teixeira, A. Pascoal, “AUV Terrain Aided Navigation using Particle Filters,“ Proc. International Workshop on Underwater Robotics, ISR Technical Report, July 2005.

[TR10] - F. Teixeira, A. Pascoal, “A Study on AUV Geomagnetic- Aided Navigation,“ ISR Technical Report, December 2005.

[TR11] - Luis Sebasti�o, Ant�nio Pascoal (ISR/IST),� Ana Cola�o, Frederico Cardigos (IMAR-DOP), “Acoustic Data Acquisition for� Automatic Benthic Habitat Classification (Laboratory Tests), “ Report� EXOCET.AC01.2005, October 2005.

[TR12] - Luis Sebasti�o, Ant�nio Pascoal (ISR/IST),� Ana Cola�o, Frederico Cardigos (IMAR/DOP), “Acoustic Data Acquisition for� Automatic Benthic Habitat Classification (Laboratory Tests), “� joint ISR-IST/IMAR-DOP EXOCET.AC01.2005 Report, October 2005. This work was carried out in the scope of the EXOCET project of the EU.

[TR13] - C. Silvestre, P. Oliveira, A. Pascoal, L. Sebasti�o, J. Alves, J. Santos, L. Silva, M. Neves, “An integrated system for acoustic data acquisition, storing, and processing: hardware and software architectures,” joint ISR-IST/LNEC internal Report, October 2005. This work was carried out in the scope of the MEDIRES project of the AdI, Portugal and the� EXOCET project of the EU.

[TR14] -� Reza Ghabcheloo, Antonio Pascoal, Carlos Silvestre, Danilo Carvalho, “Coordinated Motion Control of Multiple Fully Actuated Marine Vehicles”, joint ISR-IST/UFES (Brasil) Report, November 2005.

[TR15] - Jo�o Alves, C. Silvestre, “Real Time Architectures for Autonomous Vehicles,” ISR Technical Report, October 2005.

[TR16] - Nuno Paulino, C. Silvestre, “Terrain Tracking Control Strategies for Autonomous Vehicles with application to Unmanned Helicopters,” ISR Technical Report, October 2005.

 4. LABORATORY FACILITIES AND SERVICES

4.1. COMMON FACILITIES

Mechanical / Electric shop (8th Floor of ISR) - basic equipment and tools to machine mechanical pieces, assemble circuit boards, and test electrical / electronic circuitry.

4.2. LABORATORY FACILITIES

Robotic Vehicles

  • DELFIM Autonomous Surface Vehicle (ASC) - an autonomous surface craft� (Catamaran-type) ������������� to carry out experimental research in the area of ocean robotics and to perform scientific missions ������������� at sea.
  • DELFIM_X Autonomous Surface Vehicle (ASC) - an autonomous surface craft similar to the DELFIM, but with improved hydrodynamic characteristics.
  • INFANTE Autonomous Underwater Vehicle (AUV) – an autonomous underwater vehicle to carry out experimental research in the area of ocean robotics and to perform scientific missions at sea.
  • CARAVELA 2000 Autonomous Research Vessel –� prototype of an autonomous surface craft for long range missions at sea (co-owned by IST/ISR, IMAR/Dept. Oceanography and Fisheries of the Univ. Azores, RINAVE, and CONAFI)
  • VARIO XTREM R/C Helicopter - a small helicopter (payload of 4 Kg) to carry out experimental research in the area of autonomous aerial robotics.

Small Zodiac to support operations at sea.

Mechanical/ Electrical� Equipment

  • Pressure Chamber -� to test the marinization of equipment down to depths of 600 meters.
  • Crane with the capacity to handle loads of up to 2500 Kg.
  • Industrial air compressor.
  • Trailer for the transportation of marine vehicles.

Actuators and Sensors for Robotic Ocean Vehicle Development and Operation (part of the equipment is dedicated to the operation of the� INFANTE AUV and the� DELFIM and CARAVELA ASVs).

  • Actuators� - 5 electrical thrusters.
  • 3 rate gyros, 2 pendulums and 1 fluxgate (Watson's Attitude & Heading Reference Unit AHRS-C303);
  • 3 rate gyros, 3 accelerometers and 1 magnetometer (SEATEX MRU-6)
  • 3 rate gyros, 2 pendulums and 1 magnetometer (KVH attitude reference unit).
  • 1 flowmeter TSA-06-C-A (EG & G Flow Technology);
  • 2 depth cells DC 10R-C (Transinstruments);
  • 2 echosounders ST200 (Tritech);
  • 2 echosounders ST500 (Tritech);
  • 1 Sidescan sonar (System Techonologies / Tritech);
  • 1 Acoustic Modem for underwater communications� (System Techonologies / Tritech);
  • GIB� (GPS Intelligent Buoys) – GPS based underwater� positioning system, with target tracking capabilities.
  • 1 Doppler Log TSM 5740 with 4 beams in a Janus configuration, operating at 300 KHz (Thomson-ASM);
  • 1 Doppler Log, operating at 600 KHz, rated for 2000 m (RDI);
  • 1 set of 3 rate gyros, 2 pendulums and 1 directional gyro from Humphreys.
  • 1 Long Baseline Positioning System for underwater vehicle positioning - 1 transducer and 4 transponders.
  • 1 DGPS (Differential Global Positioning System)� for accurate surface vehicle navigation - 4 Motorola Encore unit and 3 FREEWAVE radios.

Hardware and Software Development Systems for Vehicle Simulation and Real-Time Vehicle Control.

  • Hardware for real-time applications - 3 Gespac 68030/68882 computers; a T805 transputer array; 4 MPL ������������� stand-alone 68020/60881 computers.
  • 3 Single Board Computers RTD/USA
  • Development System - Microware FASTRAK development software running on a SUN-Workstation; ������������� professional OS9 for Gespac development systems.

Software Tools for Navigation, Guidance, and Control System� Design.

INTEGRA - Modeling and simulation tool for the integrated analysis and design of navigation, guidance and control systems for autonomous vehicles. The software was developed at IST/ISR and is built around the commercially available package MATLAB. The package is specially geared towards the development of dynamic models of robotic ocean vehicles. Furthermore, it provides the means to assess the combined performance of navigation, guidance and control systems prior to their implementation.

General Computer Facilities.

������������� 11 Desktop PCs

������������� 7 Laptop PCs�������������

������������� 2 Laser printers

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