This paper describes an architecture for the remote operation of a mobile platform by multiple us... more This paper describes an architecture for the remote operation of a mobile platform by multiple users using Internet. A client/server approach, developed using Java, provides the users with multiple control and sensing functionalities. Experimental results obtained under regular network traffic are presented.
Abstract This paper describes the control of a car-like mobile robot using a hybrid strategy. The... more Abstract This paper describes the control of a car-like mobile robot using a hybrid strategy. The aim of this work is to develop a behavior based control paradigm for the control of semi-autonomous robots such that mission goals can be loosely specified. Simulation results ...
This paper describes the control of robot teams in the framework of Hilbert spaces. The paper foc... more This paper describes the control of robot teams in the framework of Hilbert spaces. The paper focus are the intrinsic properties of robot control architectures, namely the conditions under which a generic mission can be successfully executed.
An architecture for the assignment of tasks in a multirobot system is presented. The tasks arriva... more An architecture for the assignment of tasks in a multirobot system is presented. The tasks arrival times and order are not known, and no statistical distributions are assumed. Furthermore, the execution of tasks cannot be preempted and hard deadlines are imposed on both their assignment and conclusion times. The architecture design is inspired by economic markets and a performance measure, similar to market prices, is introduced. A theoretical analysis of the architecture operation is presented and the results are applied to the dimensioning of an active surveillance system for the UPC campus at Barcelona, Spain.
We present a procedure for the estimation of bids in auction protocols. This class of protocols i... more We present a procedure for the estimation of bids in auction protocols. This class of protocols is of interest to multiagent systems because they can be used to coordinate the assignment of tasks to agents. The main idea is to take advantage of methods for the synthesis of task execution controllers that rely on the availability of value functions. These provide a natural way to obtain the bid values for a given task. The approach is demonstrated on an active surveillance system, where mobile robots must approach and identify humans, and conduct patrols. The Partially Observable Markov Decision Process (POMDP) framework is used to compute policies for the execution of tasks by each agent, the task bid values are obtained directly from the respective value functions. Several simulation examples are presented for an urban surveillance environment, illustrating the applicability of our ideas. Agent POMDP Model Task A Arrival of tasks Auctioneer Auction Protocol POMDP Model Task B POMDP Model Task D POMDP Model Task C Agent POMDP Model Task A POMDP Model Task B POMDP Model Task D POMDP Model Task C Agent POMDP Model Task A POMDP Model Task B POMDP Model Task D POMDP Model Task C
This paper presents a hybrid architecture for robot control supported on basic concepts from the ... more This paper presents a hybrid architecture for robot control supported on basic concepts from the geometry of Hilbert spaces and nonsmooth calculus. The architecture develops in two classic layers. A supervising layer chooses which motion strategies to apply from a set contained in an execution layer.
In this article we explain the architecture for the environment and sensors that has been built f... more In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted. Sensors 2010, 10 2275
AbstractWe consider the problem of task assignment and execution in multirobot systems, by propo... more AbstractWe consider the problem of task assignment and execution in multirobot systems, by proposing a procedure for bid estimation in auction protocols. Auctions are of interest to multirobot systems because they provide a flexible way to coordinate the assignment of tasks to ...
This paper describes the application of basis concepts in semiotics and nonsmooth systems to robo... more This paper describes the application of basis concepts in semiotics and nonsmooth systems to robot control. The resulting framework yields a vocabulary of movements tailored to the control of semi-autonomous robots. Semiotics provides a set of classes of objects to model the interactions among humans. The paper proposes the use of these semiotic objects to model human-robot interactions, accounting for features such as semantics and ambiguity. Mathematical models for the objects are presented including objects to generate paths for the robot to follow and operators to act on such objects. Experiments with single and multiple robots illustrating the main aspects of the proposed framework are presented.
This paper describes a hybrid architecture for robot control supported on basic properties of Hil... more This paper describes a hybrid architecture for robot control supported on basic properties of Hilbert spaces. The proposed architecture is in the class of behavior based paradigms, with the control objectives specified as goal sets to be reached by the robot. This characteristic is well adapted to the control of semi-autonomous robots as tasks can be loosely specified by external operators using goal regions in the workspace where to steer the robots. Simulation results on the control of a car-like robot are presented.
Single And Multiple Robot Control: A Geometric Approach
Abstract: This report presents an approach to the control of single and multiple robot systems ba... more Abstract: This report presents an approach to the control of single and multiple robot systems based on basicgeometry properties of Hilbert spaces.
This paper presents a study on two kinematic structures for dynamically stable biped locomotion. ... more This paper presents a study on two kinematic structures for dynamically stable biped locomotion. The two legs, each with three degrees of freedom, are connected through a rigid waist. The dynamics of both structures is modelled by partitioning the six dof kinematic chain in a 3 dof supporting leg and a 3 dof balance leg. A low complexity model is obtained by simplifying the dynamics of the balance leg not accounting for rotational dynamics. It is shown that the overall model produces good results under the point mass assumption for each link and a standard robust control algorithm.
. This paper proposes an architecture to achieve cooperative behaviour among a set of robotic dev... more . This paper proposes an architecture to achieve cooperative behaviour among a set of robotic devices. The architecture, with a pure reactive nature privileges the use of local decision mechanisms instead of centralized ones. The performance assessment for the execution of a class of ...
The ever increasing desire for fully autonomous robotics triggered in recent years the interest i... more The ever increasing desire for fully autonomous robotics triggered in recent years the interest in the study of the interactions between robots and between humans and robots. The long term goal of this research field is the operation of heterogeneous teams of robots and humans using common interaction principles, such as a common form of natural language.
Experiments on Cooperative Behaviour Between Two Mobile Manipulators
Experiments on cooperative behaviour between two mobile manipulators ? ... Instituto Superior Tec... more Experiments on cooperative behaviour between two mobile manipulators ? ... Instituto Superior Tecnico / Instituto de Sistemas e Robotica IST - Torre Norte, Av. Rovisco Pais 1, P 1096 Lisboa CODEX, Portugal ... Abstract. This paper describes an experiment on cooperation ...
This paper describes an architecture for the remote operation of a mobile platform by multiple us... more This paper describes an architecture for the remote operation of a mobile platform by multiple users using Internet. A client/server approach, developed using Java, provides the users with multiple control and sensing functionalities. Experimental results obtained under regular network traffic are presented.
Abstract This paper describes the control of a car-like mobile robot using a hybrid strategy. The... more Abstract This paper describes the control of a car-like mobile robot using a hybrid strategy. The aim of this work is to develop a behavior based control paradigm for the control of semi-autonomous robots such that mission goals can be loosely specified. Simulation results ...
This paper describes the control of robot teams in the framework of Hilbert spaces. The paper foc... more This paper describes the control of robot teams in the framework of Hilbert spaces. The paper focus are the intrinsic properties of robot control architectures, namely the conditions under which a generic mission can be successfully executed.
An architecture for the assignment of tasks in a multirobot system is presented. The tasks arriva... more An architecture for the assignment of tasks in a multirobot system is presented. The tasks arrival times and order are not known, and no statistical distributions are assumed. Furthermore, the execution of tasks cannot be preempted and hard deadlines are imposed on both their assignment and conclusion times. The architecture design is inspired by economic markets and a performance measure, similar to market prices, is introduced. A theoretical analysis of the architecture operation is presented and the results are applied to the dimensioning of an active surveillance system for the UPC campus at Barcelona, Spain.
We present a procedure for the estimation of bids in auction protocols. This class of protocols i... more We present a procedure for the estimation of bids in auction protocols. This class of protocols is of interest to multiagent systems because they can be used to coordinate the assignment of tasks to agents. The main idea is to take advantage of methods for the synthesis of task execution controllers that rely on the availability of value functions. These provide a natural way to obtain the bid values for a given task. The approach is demonstrated on an active surveillance system, where mobile robots must approach and identify humans, and conduct patrols. The Partially Observable Markov Decision Process (POMDP) framework is used to compute policies for the execution of tasks by each agent, the task bid values are obtained directly from the respective value functions. Several simulation examples are presented for an urban surveillance environment, illustrating the applicability of our ideas. Agent POMDP Model Task A Arrival of tasks Auctioneer Auction Protocol POMDP Model Task B POMDP Model Task D POMDP Model Task C Agent POMDP Model Task A POMDP Model Task B POMDP Model Task D POMDP Model Task C Agent POMDP Model Task A POMDP Model Task B POMDP Model Task D POMDP Model Task C
This paper presents a hybrid architecture for robot control supported on basic concepts from the ... more This paper presents a hybrid architecture for robot control supported on basic concepts from the geometry of Hilbert spaces and nonsmooth calculus. The architecture develops in two classic layers. A supervising layer chooses which motion strategies to apply from a set contained in an execution layer.
In this article we explain the architecture for the environment and sensors that has been built f... more In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted. Sensors 2010, 10 2275
AbstractWe consider the problem of task assignment and execution in multirobot systems, by propo... more AbstractWe consider the problem of task assignment and execution in multirobot systems, by proposing a procedure for bid estimation in auction protocols. Auctions are of interest to multirobot systems because they provide a flexible way to coordinate the assignment of tasks to ...
This paper describes the application of basis concepts in semiotics and nonsmooth systems to robo... more This paper describes the application of basis concepts in semiotics and nonsmooth systems to robot control. The resulting framework yields a vocabulary of movements tailored to the control of semi-autonomous robots. Semiotics provides a set of classes of objects to model the interactions among humans. The paper proposes the use of these semiotic objects to model human-robot interactions, accounting for features such as semantics and ambiguity. Mathematical models for the objects are presented including objects to generate paths for the robot to follow and operators to act on such objects. Experiments with single and multiple robots illustrating the main aspects of the proposed framework are presented.
This paper describes a hybrid architecture for robot control supported on basic properties of Hil... more This paper describes a hybrid architecture for robot control supported on basic properties of Hilbert spaces. The proposed architecture is in the class of behavior based paradigms, with the control objectives specified as goal sets to be reached by the robot. This characteristic is well adapted to the control of semi-autonomous robots as tasks can be loosely specified by external operators using goal regions in the workspace where to steer the robots. Simulation results on the control of a car-like robot are presented.
Single And Multiple Robot Control: A Geometric Approach
Abstract: This report presents an approach to the control of single and multiple robot systems ba... more Abstract: This report presents an approach to the control of single and multiple robot systems based on basicgeometry properties of Hilbert spaces.
This paper presents a study on two kinematic structures for dynamically stable biped locomotion. ... more This paper presents a study on two kinematic structures for dynamically stable biped locomotion. The two legs, each with three degrees of freedom, are connected through a rigid waist. The dynamics of both structures is modelled by partitioning the six dof kinematic chain in a 3 dof supporting leg and a 3 dof balance leg. A low complexity model is obtained by simplifying the dynamics of the balance leg not accounting for rotational dynamics. It is shown that the overall model produces good results under the point mass assumption for each link and a standard robust control algorithm.
. This paper proposes an architecture to achieve cooperative behaviour among a set of robotic dev... more . This paper proposes an architecture to achieve cooperative behaviour among a set of robotic devices. The architecture, with a pure reactive nature privileges the use of local decision mechanisms instead of centralized ones. The performance assessment for the execution of a class of ...
The ever increasing desire for fully autonomous robotics triggered in recent years the interest i... more The ever increasing desire for fully autonomous robotics triggered in recent years the interest in the study of the interactions between robots and between humans and robots. The long term goal of this research field is the operation of heterogeneous teams of robots and humans using common interaction principles, such as a common form of natural language.
Experiments on Cooperative Behaviour Between Two Mobile Manipulators
Experiments on cooperative behaviour between two mobile manipulators ? ... Instituto Superior Tec... more Experiments on cooperative behaviour between two mobile manipulators ? ... Instituto Superior Tecnico / Instituto de Sistemas e Robotica IST - Torre Norte, Av. Rovisco Pais 1, P 1096 Lisboa CODEX, Portugal ... Abstract. This paper describes an experiment on cooperation ...
Uploads
Papers by Joao Sequeira