Jerome Jouffroy | University of Southern Denmark (original) (raw)
Papers by Jerome Jouffroy
This paper presents a formation modelling scheme based on a set of inter-body constraint function... more This paper presents a formation modelling scheme based on a set of inter-body constraint functions and Lagrangian multipliers. Formation control for a fleet of marine craft is achieved by stabilizing the auxiliary constraints such that the desired formation configuration appears. In the proposed framework we develop robust control laws for marine surface vessels to counteract unknown, slowly varying, environmental disturbances
Proceedings of OCEANS 2005 MTS/IEEE
This article presents a method for formation control of marine surface vessels inspired by Lagran... more This article presents a method for formation control of marine surface vessels inspired by Lagrangian mechanics. The desired formation configuration is given as a set of constraint functions. The functions are treated analytically and by using feedback from the imposed constraint functions, constraint forces arise. Since the constraint functions are designed for a desired effect, the forces can be seen as control laws. These forces act so that the constraint functions are satisfied in order to keep the formation assembled during operations. Examples of constraint functions that can be used to maintain a formation are presented. Simulations with surface vessel models have been performed to illustrate the proposed method
Modeling, Identification and Control: A Norwegian Research Bulletin, 2010
This paper introduces a methodology for differential nonlinear stability analysis using contracti... more This paper introduces a methodology for differential nonlinear stability analysis using contraction theory (Lohmiller and Slotine, 1998). The methodology includes four distinct steps: the descriptions of two systems to be compared (the plant and the observer in the case of observer convergence analysis, the plant and the controller in the case of tracking controller analysis), the definition of an abstract system common to the two systems and denoted as the "virtual system", and the convergence study of the virtual system using its virtual dynamics representation. The approach is illustrated on several simple examples.
IFAC Proceedings Volumes, 2007
Diffusion-based trajectory observers have been recently proposed as a simple and efficient framew... more Diffusion-based trajectory observers have been recently proposed as a simple and efficient framework to solve diverse smoothing problems in underwater navigation. For instance, to obtain estimates of the trajectories of an underwater vehicle given position fixes from an acoustic positioning system and velocity measurements from a DVL. The observers are conceptually simple and can easily deal with the problems brought about by the occurrence of asynchronous measurements and dropouts. In its original formulation, the trajectory observers depend on a user-defined constant gain that controls the level of smoothing and is determined by resorting to trial and error. This paper presents a methodology to choose the observer gain by taking into account a priori information on the variance of the position measurement errors. Experimental results with data from an acoustic positioning system are presented to illustrate the performance of the derived observers.
Despite their interesting dynamic and controllability properties, sailing vehicles have not been ... more Despite their interesting dynamic and controllability properties, sailing vehicles have not been much studied in the control community. In this paper, we investigate motion planning of such vehicles. Starting from a simple dynamic model of sailing vessels in one dimension, this paper first considers their associated controllability issues, with the so-called no-sailing zone as a starting point, and it links them with a motion planning strategy using two-point boundary value problems as the main mathematical tool. This perspective is then expanded to do point-to-point maneuvers of sailing vehicles in the plane, that is, automatic path generation combined with computation of control input profiles. Simulations are presented to illustrate the potential of the approach.
2019 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM)
2018 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM)
Modeling, Identification and Control: A Norwegian Research Bulletin
This paper considers the on-line implementation of the modulating function method, for parameter ... more This paper considers the on-line implementation of the modulating function method, for parameter and state estimation, for the model of an air-handling unit, central element of HVAC systems. After recalling the few elements of the method, more attention is paid on issues related to its on-line implementation, issues for which we use two different techniques. Experimental results are obtained after implementation of the algorithms on a heat flow experiment, and they are compared with conventional techniques (conventional tools from Matlab for parameter estimation, and a simple Luenberger observer for state estimation) for their validation.
OCEANS'11 MTS/IEEE KONA, 2011
Autonomous Lagrangian profilers are widely used as measurement and monitoring platforms. In their... more Autonomous Lagrangian profilers are widely used as measurement and monitoring platforms. In their current mode of operation, the profilers usually drift passively at their parking depth before making a vertical profile to go back to the surface. This paper presents a control strategy to actively select and use tidal currents so that a profiler can autonomously reach a desired destination. After presenting the profiler and possible modifications for a coastal environment, we introduce simple mathematical models for the profiler and its environment. We then present a feedback controller that, taking into account the direction of oscillating tidal currents, is able to steer the profiler to any horizontal location. For illustration, we also give a few simulation results using tidal current data from the North Sea.
OCEANS'11 MTS/IEEE KONA, 2011
Page 1. Modeling and Nonlinear Heading Control ... Simulation results are briefly presented to il... more Page 1. Modeling and Nonlinear Heading Control ... Simulation results are briefly presented to illustrate the approach. ... Note that, in the following discussion, we consider the vehicle to evolve in calm waters, ie the motions due to waves and environmental disturbances are ignored. ...
2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016
IFAC Proceedings Volumes, 2012
IFAC Proceedings Volumes, 2010
IFAC Proceedings Volumes, 2002
While the use of Lyapunov function candidates for integrator backstepping has been extensively st... more While the use of Lyapunov function candidates for integrator backstepping has been extensively studied in the literature, little research has been conducted regarding the applicability of the so-called incremental stability approaches. This note addresses the problem of the use of an incremental approach, i.e. contraction theory, to the integrator backstepping design on the methodological aspect. After briefly recalling basic results from contraction theory, a full contraction-based integrator backstepping procedure is presented. An example is given to illustrate the method.
9th IFAC Conference on Manoeuvring and Control of Marine Craft, 2012, 2012
Autonomous sailing platforms or sailing robots are a class of autonomous surface vehicles using o... more Autonomous sailing platforms or sailing robots are a class of autonomous surface vehicles using only the wind as their means of propulsion. In order to adapt to harsh conditions at sea, a robust design of an autonomous sailing platform is presented in this paper. The proposed sailing robot consists of a hull to which are attached a fixed and rigid sail, and an internal moving weight system used for steering. The control objective is to maintain a desired heading angle for the platform by automatically controlling the movable mass. Two different weight balancing mechanisms, i.e. a so-called linear weight mechanism and a pendulum mechanism, are introduced together with the mathematical model of the vehicle, exposed to ocean currents and wind variations. Furthermore, to allow maneuverability, dimensioning of the mass weight and the vehicle beam (or the pendulum length) are considered through simple nonlinear controllability properties using flatness theory. Finally, we present an exponentially stable heading controller based on backstepping and contraction theory, and which explicitly takes into account the presence of currents.
Proceedings of the 2009 Ieee International Conference on Systems Man and Cybernetics, Oct 11, 2009
ABSTRACT Sailing vessels such as sailboats but also landyachts are vehicles representing a real c... more ABSTRACT Sailing vessels such as sailboats but also landyachts are vehicles representing a real challenge for automation. However, the control aspects of such vehicles were hitherto very little studied. This paper presents a simplified dynamic model of a so-called landyacht allowing to capture the main elements of the behavior of surface sailing vessels. We then propose a path generation scheme and a controller design for a well-known and fundamental maneuver in sailing referred to as tacking. Simulation results are presented to illustrate the approach.
2003 European Control Conference, Sep 1, 2003
On the contrary to Lyapunov theory, contraction theory studies system behavior independently from... more On the contrary to Lyapunov theory, contraction theory studies system behavior independently from a specific attractor, thus leading to simpler computations when verifying exponential convergence of nonlinear systems. To check the contraction property, a condition of negativity on the Jacobian of the system has to be fulfilled. In this paper, attention is paid to results for which the negativity condition can be relaxed, i.e. the maximum eigenvalue of the Jacobian may take zero or positive values. In this issue, we present a theorem and a corollary which sufficient conditions enable to conclude when the Jacobian is not uniformly negative definite but fulfils some weaker conditions. Intended as an illustrative example, a nonlinear underwater vehicle observer, which Jacobian is not uniformly negative definite, is presented and proven to be exponentially convergent using the new criterion.
2015 IEEE Conference on Control Applications (CCA), 2015
2013 European Control Conference, Jul 17, 2013
This paper presents a formation modelling scheme based on a set of inter-body constraint function... more This paper presents a formation modelling scheme based on a set of inter-body constraint functions and Lagrangian multipliers. Formation control for a fleet of marine craft is achieved by stabilizing the auxiliary constraints such that the desired formation configuration appears. In the proposed framework we develop robust control laws for marine surface vessels to counteract unknown, slowly varying, environmental disturbances
Proceedings of OCEANS 2005 MTS/IEEE
This article presents a method for formation control of marine surface vessels inspired by Lagran... more This article presents a method for formation control of marine surface vessels inspired by Lagrangian mechanics. The desired formation configuration is given as a set of constraint functions. The functions are treated analytically and by using feedback from the imposed constraint functions, constraint forces arise. Since the constraint functions are designed for a desired effect, the forces can be seen as control laws. These forces act so that the constraint functions are satisfied in order to keep the formation assembled during operations. Examples of constraint functions that can be used to maintain a formation are presented. Simulations with surface vessel models have been performed to illustrate the proposed method
Modeling, Identification and Control: A Norwegian Research Bulletin, 2010
This paper introduces a methodology for differential nonlinear stability analysis using contracti... more This paper introduces a methodology for differential nonlinear stability analysis using contraction theory (Lohmiller and Slotine, 1998). The methodology includes four distinct steps: the descriptions of two systems to be compared (the plant and the observer in the case of observer convergence analysis, the plant and the controller in the case of tracking controller analysis), the definition of an abstract system common to the two systems and denoted as the "virtual system", and the convergence study of the virtual system using its virtual dynamics representation. The approach is illustrated on several simple examples.
IFAC Proceedings Volumes, 2007
Diffusion-based trajectory observers have been recently proposed as a simple and efficient framew... more Diffusion-based trajectory observers have been recently proposed as a simple and efficient framework to solve diverse smoothing problems in underwater navigation. For instance, to obtain estimates of the trajectories of an underwater vehicle given position fixes from an acoustic positioning system and velocity measurements from a DVL. The observers are conceptually simple and can easily deal with the problems brought about by the occurrence of asynchronous measurements and dropouts. In its original formulation, the trajectory observers depend on a user-defined constant gain that controls the level of smoothing and is determined by resorting to trial and error. This paper presents a methodology to choose the observer gain by taking into account a priori information on the variance of the position measurement errors. Experimental results with data from an acoustic positioning system are presented to illustrate the performance of the derived observers.
Despite their interesting dynamic and controllability properties, sailing vehicles have not been ... more Despite their interesting dynamic and controllability properties, sailing vehicles have not been much studied in the control community. In this paper, we investigate motion planning of such vehicles. Starting from a simple dynamic model of sailing vessels in one dimension, this paper first considers their associated controllability issues, with the so-called no-sailing zone as a starting point, and it links them with a motion planning strategy using two-point boundary value problems as the main mathematical tool. This perspective is then expanded to do point-to-point maneuvers of sailing vehicles in the plane, that is, automatic path generation combined with computation of control input profiles. Simulations are presented to illustrate the potential of the approach.
2019 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM)
2018 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM)
Modeling, Identification and Control: A Norwegian Research Bulletin
This paper considers the on-line implementation of the modulating function method, for parameter ... more This paper considers the on-line implementation of the modulating function method, for parameter and state estimation, for the model of an air-handling unit, central element of HVAC systems. After recalling the few elements of the method, more attention is paid on issues related to its on-line implementation, issues for which we use two different techniques. Experimental results are obtained after implementation of the algorithms on a heat flow experiment, and they are compared with conventional techniques (conventional tools from Matlab for parameter estimation, and a simple Luenberger observer for state estimation) for their validation.
OCEANS'11 MTS/IEEE KONA, 2011
Autonomous Lagrangian profilers are widely used as measurement and monitoring platforms. In their... more Autonomous Lagrangian profilers are widely used as measurement and monitoring platforms. In their current mode of operation, the profilers usually drift passively at their parking depth before making a vertical profile to go back to the surface. This paper presents a control strategy to actively select and use tidal currents so that a profiler can autonomously reach a desired destination. After presenting the profiler and possible modifications for a coastal environment, we introduce simple mathematical models for the profiler and its environment. We then present a feedback controller that, taking into account the direction of oscillating tidal currents, is able to steer the profiler to any horizontal location. For illustration, we also give a few simulation results using tidal current data from the North Sea.
OCEANS'11 MTS/IEEE KONA, 2011
Page 1. Modeling and Nonlinear Heading Control ... Simulation results are briefly presented to il... more Page 1. Modeling and Nonlinear Heading Control ... Simulation results are briefly presented to illustrate the approach. ... Note that, in the following discussion, we consider the vehicle to evolve in calm waters, ie the motions due to waves and environmental disturbances are ignored. ...
2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016
IFAC Proceedings Volumes, 2012
IFAC Proceedings Volumes, 2010
IFAC Proceedings Volumes, 2002
While the use of Lyapunov function candidates for integrator backstepping has been extensively st... more While the use of Lyapunov function candidates for integrator backstepping has been extensively studied in the literature, little research has been conducted regarding the applicability of the so-called incremental stability approaches. This note addresses the problem of the use of an incremental approach, i.e. contraction theory, to the integrator backstepping design on the methodological aspect. After briefly recalling basic results from contraction theory, a full contraction-based integrator backstepping procedure is presented. An example is given to illustrate the method.
9th IFAC Conference on Manoeuvring and Control of Marine Craft, 2012, 2012
Autonomous sailing platforms or sailing robots are a class of autonomous surface vehicles using o... more Autonomous sailing platforms or sailing robots are a class of autonomous surface vehicles using only the wind as their means of propulsion. In order to adapt to harsh conditions at sea, a robust design of an autonomous sailing platform is presented in this paper. The proposed sailing robot consists of a hull to which are attached a fixed and rigid sail, and an internal moving weight system used for steering. The control objective is to maintain a desired heading angle for the platform by automatically controlling the movable mass. Two different weight balancing mechanisms, i.e. a so-called linear weight mechanism and a pendulum mechanism, are introduced together with the mathematical model of the vehicle, exposed to ocean currents and wind variations. Furthermore, to allow maneuverability, dimensioning of the mass weight and the vehicle beam (or the pendulum length) are considered through simple nonlinear controllability properties using flatness theory. Finally, we present an exponentially stable heading controller based on backstepping and contraction theory, and which explicitly takes into account the presence of currents.
Proceedings of the 2009 Ieee International Conference on Systems Man and Cybernetics, Oct 11, 2009
ABSTRACT Sailing vessels such as sailboats but also landyachts are vehicles representing a real c... more ABSTRACT Sailing vessels such as sailboats but also landyachts are vehicles representing a real challenge for automation. However, the control aspects of such vehicles were hitherto very little studied. This paper presents a simplified dynamic model of a so-called landyacht allowing to capture the main elements of the behavior of surface sailing vessels. We then propose a path generation scheme and a controller design for a well-known and fundamental maneuver in sailing referred to as tacking. Simulation results are presented to illustrate the approach.
2003 European Control Conference, Sep 1, 2003
On the contrary to Lyapunov theory, contraction theory studies system behavior independently from... more On the contrary to Lyapunov theory, contraction theory studies system behavior independently from a specific attractor, thus leading to simpler computations when verifying exponential convergence of nonlinear systems. To check the contraction property, a condition of negativity on the Jacobian of the system has to be fulfilled. In this paper, attention is paid to results for which the negativity condition can be relaxed, i.e. the maximum eigenvalue of the Jacobian may take zero or positive values. In this issue, we present a theorem and a corollary which sufficient conditions enable to conclude when the Jacobian is not uniformly negative definite but fulfils some weaker conditions. Intended as an illustrative example, a nonlinear underwater vehicle observer, which Jacobian is not uniformly negative definite, is presented and proven to be exponentially convergent using the new criterion.
2015 IEEE Conference on Control Applications (CCA), 2015
2013 European Control Conference, Jul 17, 2013