joao sousa - Academia.edu (original) (raw)

Papers by joao sousa

Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228)

runway at sea. The unprecedented length of the at-sea runway (up to a mile long) warrants the use... more runway at sea. The unprecedented length of the at-sea runway (up to a mile long) warrants the use of several modules. In each of these cases, there is a need for inter-vehicle communications so that each vehicle can know the status of the operation, the position of its counterparts, and whether the specific mission goals have changed. Thus the control and communication problems become inexorably tied. However, few results are available to analyze performance and stability of a closed loop system where some of the loops are closed by communicated variables. Using the above examples as a motivation, this paper examines emerging results in networked multi-vehicle systems. Recent work has taken many different approaches, such as hybrid systems, distributed control, differential games, control architectures, and artificial intelligence. The focus of this paper is on the control systems perspective. We attempt to present some current issues common to networked multivehicle systems, and to show how they have been solved to date in the perspective of the case studies. Index Terms-networked multi-vehicle systems, communications and control, hybrid systems, control architectures, multi-agent systems.

42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475)

A framework the representation and control of networked vehicle systems is presented. From set th... more A framework the representation and control of networked vehicle systems is presented. From set theory, this framework borrowed the representational power of the language of sets to capture the relations among vehicles and controllers in a way that is consistent with control design. From dynamic optimization, this framework has inherited the concepts and theories of optimality, reach set computation and control, the techniques to operate on sets and dynamic systems, and the motivation to improve the performance of increasingly complex physical processes.

Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492), 2003

This paper presents the user-assisted trajectory generation module of a control system for autono... more This paper presents the user-assisted trajectory generation module of a control system for autonomous and remotely operated vehicles. The control system is composed of three main modules: user interface, trajectory generation and feedback control. The paper reports the integrated design of the user interface and of the trajectory generation module and discusses how this design can impact the overall system performance. The approach to trajectory generation is based on the techniques from differential fl atness.

Unmanned Ground Vehicle Technology, 1999

We are developing dynamic position (DP) control and evaluation systems for semi-submersible vesse... more We are developing dynamic position (DP) control and evaluation systems for semi-submersible vessel system called a Mobile Offshore Base (MOB). In concept, the MOB is a self-propelled prepositioned floating base consisting of three to five vessels, and comprising a mile-long runway to accommodate C-17 takeoff and landing operations and allow cargo transfer from container ships. Separate MOB barges would embark toward a preposition point about 100 km offshore, assemble along a line, then execute a military mission in a variety of sea states. Specific concepts call for them to be mechanically or electronically linked, while a concept refinement uses a hybrid approach, linking them mechanically during low sea states and electronically once the environmental disturbances increase. We discuss issues and approaches with MOB control, with a focus on the overarching control architecture. We frame our discussion, however, on microsimulation techniques derived from a discipline best described as simulation of dynamically reconfigurable multi-agent hybrid dynamic systems. Specifically we describe the intended use of our microsimulation technique to evaluate various control concepts and ultimately, to test the feasibility of employing DP on the MOB.

OCEANS Conference, 2001

An automated maneuver control framework for a remotely operate vehicle (ROV) is presented. This f... more An automated maneuver control framework for a remotely operate vehicle (ROV) is presented. This framework entails a three-layered control architecture, a principled approach to design and implementation within the architecture, and hybrid systems design techniques. The control architecture is structured according to the principle of composition of vehicle motions from a minimal set of elemental maneuvers that are designed and

Proceedings - IEEE International Conference on Robotics and Automation, 2006

The C3I (Command, Control, Communication and Information) Neptus framework which is being develop... more The C3I (Command, Control, Communication and Information) Neptus framework which is being developed at the Underwater Systems and Technology Laboratory (USTL/LSTS) is presented. Neptus is a modular mixed initiative framework (human operators in the control loop) for the operation of heterogeneous teams of vehicles such as autonomous and remotely operated underwater, surface, land, and air vehicles. Neptus is composed of mission and vehicle planning, supervision, and post-mission analysis modules which are provided as services across a network. This paper focus mainly on the mission definition module with the presentation of MDL-a XML based language for mission definition.

2014 IEEE International Conference on Robotics and Automation (ICRA), 2014

Obtaining synoptic observations of dynamic ocean phenomena such as fronts, eddies, oxygen minimum... more Obtaining synoptic observations of dynamic ocean phenomena such as fronts, eddies, oxygen minimum zones and blooms has been challenging primarily due to the large spatial scales involved. Traditional methods of observation with manned ships are expensive and, unless the vessel can survey at high-speed, unrealistic. Autonomous underwater vehicles (AUVs) are robotic platforms that have been making steady gains in sampling capabilities and impacting oceanographic observations especially in coastal areas. However, their reach is still limited by operating constraints related to their energy sources. Unmanned aerial vehicles (UAVs) recently introduced in coastal and polar oceanographic experiments have added to the mix in observation strategy and methods. They offer a tantalizing opportunity to bridge such scales in operational oceanography by coordinating with AUVs in the water-column to get in-situ measurements. In this paper, we articulate the principal challenges in operating UAVs with AUVs making synoptic observations for such targeted watercolumn sampling. We do so in the context of autonomous control and operation for networked robotics and describe novel experiments while articulating the key challenges and lessons learned.

Oceans '97. MTS/IEEE Conference Proceedings

This paper presents the recent developments of the project Multiple Autonomous Underwater Vehicle... more This paper presents the recent developments of the project Multiple Autonomous Underwater Vehicles for Coastal Oceanography, of the University of Porto. The project envisages the development of a highly operational and low-cost system for scientific and environmental data collection in the Portuguese coastal waters. The project activities suggested the development of a Generalized Vehicle (GV) Control Architecture for multiple vehicles. Reconfigurability, reliability and operational effectiveness, are at the basis of this control architecture, which encompasses human intervention besides the cooperation among AUVs and other system devices. A simulation environment was developed in SHIFT, to support the design and testing of the GV control architecture. SHIFT is a new specification language for describing dynamic networks of hybrid automata, which constitute the most adequate formalism for this problem domain.

Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492), 2003

The integrated maneuver and control structures for a Remotely Operated Vehicle are presented in t... more The integrated maneuver and control structures for a Remotely Operated Vehicle are presented in the context of the developments of "IES-Inspection of Underwater Structures" project. The project concerns the design and implementation of an advanced low cost system for the inspection of underwater structures based on a Remotely Operated Vehicle (ROV). First, the subsystems of the IES system are described. Second, an example of a mission is outlined. Third, the control architecture is briefly sketched and formalized. Fourth, the design of the regulation and tracking controllers for this architecture are discussed. The design uses a non-linear Dynamic Surface Controller (DSC). This controller is coupled with a trajectory generation system for optimal performance. The ROV model is differentially flat under mild assumptions. The trajectory generation system uses this property to produce optimal trajectories. Finally, simulation runs of DSC and PID are compared in light of model parameters uncertainty. Extensions of the work are discussed as conclusions.

Proceedings of International Conference on Robotics and Automation

This paper addresses the design of a hybrid feedback control system enabling a car-like, rectangu... more This paper addresses the design of a hybrid feedback control system enabling a car-like, rectangular vehicle to perform a tight L-shaped turn manoeuvre. This case constitutes an effort towards the definition of a general purpose methodology for hybrid feedback control synthesis. The design effort encompasses the synthesis of a set of modalities and mechanisms to detect relevant events enabling the

Networks and Heterogeneous Media, 2009

Ne tw or ke d co op er at io n USTL Cooperation Does not include projects

OCEANS 2011 IEEE - Spain, 2011

Developing obstacle avoidance algorithms for low cost Autonomous Underwater Vehicles using single... more Developing obstacle avoidance algorithms for low cost Autonomous Underwater Vehicles using single beam returned echo sounder sonar is a difficult task. In this paper, we propose an intelligent obstacle avoidance algorithm that maps the obstacle, avoids it with a guarantee that it will not get stuck and efficiently traverses a path towards the destination using navigation functions. We present a complete obstacle avoidance system with the help of hybrid automata, probabilistic mapping and navigation functions. Simulation results are presented showing the validity of our approach.

OCEANS 2007 - Europe, 2007

Underwater acoustic networks can be quite effective to establish communication links between auto... more Underwater acoustic networks can be quite effective to establish communication links between autonomous underwater vehicles (AUVs) and other vehicles or control units, enabling complex vehicle applications and control scenarios. A communications and control framework to support the use of underwater acoustic networks and sample application scenarios are described for single and multi-AUV operation.

Europe Oceans 2005, 2005

This paper reports the design of a new remotely operated underwater vehicle WOV), which has been ... more This paper reports the design of a new remotely operated underwater vehicle WOV), which has been developed at the Underwater Systems and Technology Laboratory (USTL)-University of Porto. This design is contextualized on the KOS project (Kits for Underwater operations). The main issues addressed here concern directional drag minimization, symmetry, optimized thruster positioning, stability and layout of ROV components. This design is aimed at optimizing ROV performance for a set of different operational scenarios, This is achieved through modular configurations which are optimized for each different scenario.

2006 9th International Conference on Information Fusion, 2006

This paper presents the Mission Review and Analysis module of a C3I (Command, Control, Communicat... more This paper presents the Mission Review and Analysis module of a C3I (Command, Control, Communication and Information) infrastructure-the Neptus framework. This is a mix-initiative environment that it's being developed in the Underwater Systems and Technology Laboratory (USTL/LSTS) with the goal to support the coordinated operation of heterogeneous teams of vehicles. This includes autonomous and remotely operated underwater, surface, land, and air vehicles and people. People perform a fundamental role, not only in the case of remotely operated vehicles, but also with autonomous vehicles where mix-initiative operation is a requirement. The Neptus is very modular and will be heavily based on services with a distributed architecture. This paper focus mainly on the mission review and analysis where the data collected in a mission is prepared for analysis.

Collaborative Systems for Production Management, 2003

The task of coordinating business agents to accomplish complex goals, which could not be accompli... more The task of coordinating business agents to accomplish complex goals, which could not be accomplished by any of the agents on its own, is a complex one. This paper addresses the problem of coordinating companies within a general architecture for e-cooperation. This architecture articulates the interoperation of business process over the Internet with varied degrees of security requirements. The implementation infrastructure is used to support the cooperative design and construction of production facilities (spot-welding lines, assembly lines). These are typically complex systems, which are made of several subsystems (robots, machines, cells), that are designed and built by different companies in different countries. Design and construction involves several types of companies, from OEMs to small engineering houses. With this architecture we aim at improving the otherwise time consuming task of coordinating their activities, especially when models (geometric, process, and workflow models), machine programs, documentation, etc. must be exchanged frequently and secnrely.

The Mobile Offshore Base (MOB) is a large, self-propelled, floating, pre-positioned ocean structu... more The Mobile Offshore Base (MOB) is a large, self-propelled, floating, pre-positioned ocean structure formed of three to five modules and reaching up to 1,500 meters in length. It must accommodate the landing and take-off of C -17 conventional aircraft, host 3000 troops, carry 10 million gallons of fuel and provide 3 million square feet of internal configurable storage. The alignment of the modules,is maintained through the use of slew-able thrusters and/or connectors. The University of California at Berkeley’s involvement,with the ONR Mobile Offshore Base project resulted in a three-year effort meant to provide insight into the design and architecture of coordinated DP systems (systems involving the DP of a structure or vessel relative to another floating ocean structure or vessel), a simulation environment in which different MOB concepts could be tested and evaluated, and an experimental scaled platform (1:150) on which,the coordinated DP control algorithms were implemented and eval...

Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007

This video shows a brief overview over Neptus, a command and control infrastructure for heterogen... more This video shows a brief overview over Neptus, a command and control infrastructure for heterogeneous teams of autonomous vehicles. Having different types of vehicles at our laboratory and from our partners, there was an increasing need to create a common infrastructure to all these systems. Additionally, a tool to support the entire mission life cycle (Planning, Execution, Review and Dissemination) was lacking. Neptus was created to provide vehicle independence and seamless inter-systems communications. Currently, Neptus has been already tested with Remotely Operated Vehicles, Autonomous Underwater Vehicles, Unmanned Air Vehicles, Autonomous Surface Vehicles and Wireless Sensor Networks. Some of these systems were operated simultaneously by various operating consoles that were sharing the same communication infrastructure. The received data was being relayed to a web server that allowed for the real-time mission following by using a common web browser.

2013 European Control Conference (ECC), 2013

Path following is the simplest desired autonomous navigation capability for UAVs. Several approac... more Path following is the simplest desired autonomous navigation capability for UAVs. Several approaches have been developed in the literature for path following. However, there is no adequate information on the comparison analysis of these algorithms. In this paper, we compare five path following algorithms that are easy to implement, take less implementation time and are robust to disturbances. The comparison of these guidance laws is carried out through simulations using the total cross-track error and control effort performance metrics.

2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2015

Supervision and control of Autonomous underwater vehicles (AUVs) has traditionally been focused o... more Supervision and control of Autonomous underwater vehicles (AUVs) has traditionally been focused on an operator determining a priori the sequence of waypoints of a single vehicle for a mission. As AUVs become more ubiquitous as a scientific tool, we envision the need for controlling multiple vehicles which would impose less cognitive burden on the operator with a more abstract form of human-in-the-loop control. Such mixed-initiative methods in goal-oriented commanding are new for the oceanographic domain and we describe the motivations and preliminary experiments with multiple vehicles operating simultaneously in the water, using a shore-based automated planner.

Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228)

runway at sea. The unprecedented length of the at-sea runway (up to a mile long) warrants the use... more runway at sea. The unprecedented length of the at-sea runway (up to a mile long) warrants the use of several modules. In each of these cases, there is a need for inter-vehicle communications so that each vehicle can know the status of the operation, the position of its counterparts, and whether the specific mission goals have changed. Thus the control and communication problems become inexorably tied. However, few results are available to analyze performance and stability of a closed loop system where some of the loops are closed by communicated variables. Using the above examples as a motivation, this paper examines emerging results in networked multi-vehicle systems. Recent work has taken many different approaches, such as hybrid systems, distributed control, differential games, control architectures, and artificial intelligence. The focus of this paper is on the control systems perspective. We attempt to present some current issues common to networked multivehicle systems, and to show how they have been solved to date in the perspective of the case studies. Index Terms-networked multi-vehicle systems, communications and control, hybrid systems, control architectures, multi-agent systems.

42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475)

A framework the representation and control of networked vehicle systems is presented. From set th... more A framework the representation and control of networked vehicle systems is presented. From set theory, this framework borrowed the representational power of the language of sets to capture the relations among vehicles and controllers in a way that is consistent with control design. From dynamic optimization, this framework has inherited the concepts and theories of optimality, reach set computation and control, the techniques to operate on sets and dynamic systems, and the motivation to improve the performance of increasingly complex physical processes.

Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492), 2003

This paper presents the user-assisted trajectory generation module of a control system for autono... more This paper presents the user-assisted trajectory generation module of a control system for autonomous and remotely operated vehicles. The control system is composed of three main modules: user interface, trajectory generation and feedback control. The paper reports the integrated design of the user interface and of the trajectory generation module and discusses how this design can impact the overall system performance. The approach to trajectory generation is based on the techniques from differential fl atness.

Unmanned Ground Vehicle Technology, 1999

We are developing dynamic position (DP) control and evaluation systems for semi-submersible vesse... more We are developing dynamic position (DP) control and evaluation systems for semi-submersible vessel system called a Mobile Offshore Base (MOB). In concept, the MOB is a self-propelled prepositioned floating base consisting of three to five vessels, and comprising a mile-long runway to accommodate C-17 takeoff and landing operations and allow cargo transfer from container ships. Separate MOB barges would embark toward a preposition point about 100 km offshore, assemble along a line, then execute a military mission in a variety of sea states. Specific concepts call for them to be mechanically or electronically linked, while a concept refinement uses a hybrid approach, linking them mechanically during low sea states and electronically once the environmental disturbances increase. We discuss issues and approaches with MOB control, with a focus on the overarching control architecture. We frame our discussion, however, on microsimulation techniques derived from a discipline best described as simulation of dynamically reconfigurable multi-agent hybrid dynamic systems. Specifically we describe the intended use of our microsimulation technique to evaluate various control concepts and ultimately, to test the feasibility of employing DP on the MOB.

OCEANS Conference, 2001

An automated maneuver control framework for a remotely operate vehicle (ROV) is presented. This f... more An automated maneuver control framework for a remotely operate vehicle (ROV) is presented. This framework entails a three-layered control architecture, a principled approach to design and implementation within the architecture, and hybrid systems design techniques. The control architecture is structured according to the principle of composition of vehicle motions from a minimal set of elemental maneuvers that are designed and

Proceedings - IEEE International Conference on Robotics and Automation, 2006

The C3I (Command, Control, Communication and Information) Neptus framework which is being develop... more The C3I (Command, Control, Communication and Information) Neptus framework which is being developed at the Underwater Systems and Technology Laboratory (USTL/LSTS) is presented. Neptus is a modular mixed initiative framework (human operators in the control loop) for the operation of heterogeneous teams of vehicles such as autonomous and remotely operated underwater, surface, land, and air vehicles. Neptus is composed of mission and vehicle planning, supervision, and post-mission analysis modules which are provided as services across a network. This paper focus mainly on the mission definition module with the presentation of MDL-a XML based language for mission definition.

2014 IEEE International Conference on Robotics and Automation (ICRA), 2014

Obtaining synoptic observations of dynamic ocean phenomena such as fronts, eddies, oxygen minimum... more Obtaining synoptic observations of dynamic ocean phenomena such as fronts, eddies, oxygen minimum zones and blooms has been challenging primarily due to the large spatial scales involved. Traditional methods of observation with manned ships are expensive and, unless the vessel can survey at high-speed, unrealistic. Autonomous underwater vehicles (AUVs) are robotic platforms that have been making steady gains in sampling capabilities and impacting oceanographic observations especially in coastal areas. However, their reach is still limited by operating constraints related to their energy sources. Unmanned aerial vehicles (UAVs) recently introduced in coastal and polar oceanographic experiments have added to the mix in observation strategy and methods. They offer a tantalizing opportunity to bridge such scales in operational oceanography by coordinating with AUVs in the water-column to get in-situ measurements. In this paper, we articulate the principal challenges in operating UAVs with AUVs making synoptic observations for such targeted watercolumn sampling. We do so in the context of autonomous control and operation for networked robotics and describe novel experiments while articulating the key challenges and lessons learned.

Oceans '97. MTS/IEEE Conference Proceedings

This paper presents the recent developments of the project Multiple Autonomous Underwater Vehicle... more This paper presents the recent developments of the project Multiple Autonomous Underwater Vehicles for Coastal Oceanography, of the University of Porto. The project envisages the development of a highly operational and low-cost system for scientific and environmental data collection in the Portuguese coastal waters. The project activities suggested the development of a Generalized Vehicle (GV) Control Architecture for multiple vehicles. Reconfigurability, reliability and operational effectiveness, are at the basis of this control architecture, which encompasses human intervention besides the cooperation among AUVs and other system devices. A simulation environment was developed in SHIFT, to support the design and testing of the GV control architecture. SHIFT is a new specification language for describing dynamic networks of hybrid automata, which constitute the most adequate formalism for this problem domain.

Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492), 2003

The integrated maneuver and control structures for a Remotely Operated Vehicle are presented in t... more The integrated maneuver and control structures for a Remotely Operated Vehicle are presented in the context of the developments of "IES-Inspection of Underwater Structures" project. The project concerns the design and implementation of an advanced low cost system for the inspection of underwater structures based on a Remotely Operated Vehicle (ROV). First, the subsystems of the IES system are described. Second, an example of a mission is outlined. Third, the control architecture is briefly sketched and formalized. Fourth, the design of the regulation and tracking controllers for this architecture are discussed. The design uses a non-linear Dynamic Surface Controller (DSC). This controller is coupled with a trajectory generation system for optimal performance. The ROV model is differentially flat under mild assumptions. The trajectory generation system uses this property to produce optimal trajectories. Finally, simulation runs of DSC and PID are compared in light of model parameters uncertainty. Extensions of the work are discussed as conclusions.

Proceedings of International Conference on Robotics and Automation

This paper addresses the design of a hybrid feedback control system enabling a car-like, rectangu... more This paper addresses the design of a hybrid feedback control system enabling a car-like, rectangular vehicle to perform a tight L-shaped turn manoeuvre. This case constitutes an effort towards the definition of a general purpose methodology for hybrid feedback control synthesis. The design effort encompasses the synthesis of a set of modalities and mechanisms to detect relevant events enabling the

Networks and Heterogeneous Media, 2009

Ne tw or ke d co op er at io n USTL Cooperation Does not include projects

OCEANS 2011 IEEE - Spain, 2011

Developing obstacle avoidance algorithms for low cost Autonomous Underwater Vehicles using single... more Developing obstacle avoidance algorithms for low cost Autonomous Underwater Vehicles using single beam returned echo sounder sonar is a difficult task. In this paper, we propose an intelligent obstacle avoidance algorithm that maps the obstacle, avoids it with a guarantee that it will not get stuck and efficiently traverses a path towards the destination using navigation functions. We present a complete obstacle avoidance system with the help of hybrid automata, probabilistic mapping and navigation functions. Simulation results are presented showing the validity of our approach.

OCEANS 2007 - Europe, 2007

Underwater acoustic networks can be quite effective to establish communication links between auto... more Underwater acoustic networks can be quite effective to establish communication links between autonomous underwater vehicles (AUVs) and other vehicles or control units, enabling complex vehicle applications and control scenarios. A communications and control framework to support the use of underwater acoustic networks and sample application scenarios are described for single and multi-AUV operation.

Europe Oceans 2005, 2005

This paper reports the design of a new remotely operated underwater vehicle WOV), which has been ... more This paper reports the design of a new remotely operated underwater vehicle WOV), which has been developed at the Underwater Systems and Technology Laboratory (USTL)-University of Porto. This design is contextualized on the KOS project (Kits for Underwater operations). The main issues addressed here concern directional drag minimization, symmetry, optimized thruster positioning, stability and layout of ROV components. This design is aimed at optimizing ROV performance for a set of different operational scenarios, This is achieved through modular configurations which are optimized for each different scenario.

2006 9th International Conference on Information Fusion, 2006

This paper presents the Mission Review and Analysis module of a C3I (Command, Control, Communicat... more This paper presents the Mission Review and Analysis module of a C3I (Command, Control, Communication and Information) infrastructure-the Neptus framework. This is a mix-initiative environment that it's being developed in the Underwater Systems and Technology Laboratory (USTL/LSTS) with the goal to support the coordinated operation of heterogeneous teams of vehicles. This includes autonomous and remotely operated underwater, surface, land, and air vehicles and people. People perform a fundamental role, not only in the case of remotely operated vehicles, but also with autonomous vehicles where mix-initiative operation is a requirement. The Neptus is very modular and will be heavily based on services with a distributed architecture. This paper focus mainly on the mission review and analysis where the data collected in a mission is prepared for analysis.

Collaborative Systems for Production Management, 2003

The task of coordinating business agents to accomplish complex goals, which could not be accompli... more The task of coordinating business agents to accomplish complex goals, which could not be accomplished by any of the agents on its own, is a complex one. This paper addresses the problem of coordinating companies within a general architecture for e-cooperation. This architecture articulates the interoperation of business process over the Internet with varied degrees of security requirements. The implementation infrastructure is used to support the cooperative design and construction of production facilities (spot-welding lines, assembly lines). These are typically complex systems, which are made of several subsystems (robots, machines, cells), that are designed and built by different companies in different countries. Design and construction involves several types of companies, from OEMs to small engineering houses. With this architecture we aim at improving the otherwise time consuming task of coordinating their activities, especially when models (geometric, process, and workflow models), machine programs, documentation, etc. must be exchanged frequently and secnrely.

The Mobile Offshore Base (MOB) is a large, self-propelled, floating, pre-positioned ocean structu... more The Mobile Offshore Base (MOB) is a large, self-propelled, floating, pre-positioned ocean structure formed of three to five modules and reaching up to 1,500 meters in length. It must accommodate the landing and take-off of C -17 conventional aircraft, host 3000 troops, carry 10 million gallons of fuel and provide 3 million square feet of internal configurable storage. The alignment of the modules,is maintained through the use of slew-able thrusters and/or connectors. The University of California at Berkeley’s involvement,with the ONR Mobile Offshore Base project resulted in a three-year effort meant to provide insight into the design and architecture of coordinated DP systems (systems involving the DP of a structure or vessel relative to another floating ocean structure or vessel), a simulation environment in which different MOB concepts could be tested and evaluated, and an experimental scaled platform (1:150) on which,the coordinated DP control algorithms were implemented and eval...

Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007

This video shows a brief overview over Neptus, a command and control infrastructure for heterogen... more This video shows a brief overview over Neptus, a command and control infrastructure for heterogeneous teams of autonomous vehicles. Having different types of vehicles at our laboratory and from our partners, there was an increasing need to create a common infrastructure to all these systems. Additionally, a tool to support the entire mission life cycle (Planning, Execution, Review and Dissemination) was lacking. Neptus was created to provide vehicle independence and seamless inter-systems communications. Currently, Neptus has been already tested with Remotely Operated Vehicles, Autonomous Underwater Vehicles, Unmanned Air Vehicles, Autonomous Surface Vehicles and Wireless Sensor Networks. Some of these systems were operated simultaneously by various operating consoles that were sharing the same communication infrastructure. The received data was being relayed to a web server that allowed for the real-time mission following by using a common web browser.

2013 European Control Conference (ECC), 2013

Path following is the simplest desired autonomous navigation capability for UAVs. Several approac... more Path following is the simplest desired autonomous navigation capability for UAVs. Several approaches have been developed in the literature for path following. However, there is no adequate information on the comparison analysis of these algorithms. In this paper, we compare five path following algorithms that are easy to implement, take less implementation time and are robust to disturbances. The comparison of these guidance laws is carried out through simulations using the total cross-track error and control effort performance metrics.

2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2015

Supervision and control of Autonomous underwater vehicles (AUVs) has traditionally been focused o... more Supervision and control of Autonomous underwater vehicles (AUVs) has traditionally been focused on an operator determining a priori the sequence of waypoints of a single vehicle for a mission. As AUVs become more ubiquitous as a scientific tool, we envision the need for controlling multiple vehicles which would impose less cognitive burden on the operator with a more abstract form of human-in-the-loop control. Such mixed-initiative methods in goal-oriented commanding are new for the oceanographic domain and we describe the motivations and preliminary experiments with multiple vehicles operating simultaneously in the water, using a shore-based automated planner.