The Experts below are selected from a list of 112314 Experts worldwide ranked by ideXlab platform

François Chaumette - One of the best experts on this subject based on the ideXlab platform.

  • Visual servoing from spheres with paracatadioptric cameras
    2008
    Co-Authors: R. Tatsambon Fomena, François Chaumette
    Abstract:

    A paracatadioptric camera consists of the coupling of a parabolic mirror with a telecentric lens which realizes an orthographic projection to the image sensor. This type of camera provides large field of view images and has therefore potential applications for mobile and aerial robots. This paper is concerned with visual servoing using paracatadioptric cameras. A new optimal combination of visual features is proposed for visual servoing from spheres. Using this combination, a classical control law is proved to be globally stable even in the presence of Modeling Error. Experimental and simulation results validate the proposed theoretical results.

  • Visual servoing from two special compounds of features using a spherical projection model
    2008
    Co-Authors: R. Tatsambon Fomena, François Chaumette
    Abstract:

    This paper is concerned with the use of a spherical projection model to design optimal visual features for visual servoing. Here two special targets are considered: a sphere marked with two points on its surface and a sphere marked with a tangent vector to a point on its surface. For these targets we propose a new minimal set of six visual features which can be computed on classical perspective cameras. Using the new set, a classical control method is proved to be globally stable even in the presence of Modeling Error. In comparison with the previous set originally proposed for the second target, the new set draws a better camera trajectory. Finally, simulation and experimental results confirm the validity of the proposed theoretical results.

  • Visual Servoing from Spheres using a Spherical Projection Model
    Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007
    Co-Authors: Romeo Tatsambon Fomena, François Chaumette
    Abstract:

    In this paper, we investigate the use of a spherical projection model to search for optimal visual features for visual servoing. A new minimal set of three visual features is proposed for visual servoing from spheres using any central catadioptric system. Using this set of features, a classical control method is proved to be globally stable even in the presence of Modeling Error and locally stable to calibration Errors on perspective cameras. Using this type of cameras, experimental results are presented and validate the proposed theoretical results.

  • ICRA - Visual Servoing from Spheres using a Spherical Projection Model
    Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007
    Co-Authors: Romeo Tatsambon Fomena, François Chaumette
    Abstract:

    In this paper, we investigate the use of a spherical projection model to search for optimal visual features for visual servoing. A new minimal set of three visual features is proposed for visual servoing from spheres using any central catadioptric system. Using this set of features, a classical control method is proved to be globally stable even in the presence of Modeling Error and locally stable to calibration Errors on perspective cameras. Using this type of cameras, experimental results are presented and validate the proposed theoretical results.

Romeo Tatsambon Fomena - One of the best experts on this subject based on the ideXlab platform.

  • Visual Servoing from Spheres using a Spherical Projection Model
    Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007
    Co-Authors: Romeo Tatsambon Fomena, François Chaumette
    Abstract:

    In this paper, we investigate the use of a spherical projection model to search for optimal visual features for visual servoing. A new minimal set of three visual features is proposed for visual servoing from spheres using any central catadioptric system. Using this set of features, a classical control method is proved to be globally stable even in the presence of Modeling Error and locally stable to calibration Errors on perspective cameras. Using this type of cameras, experimental results are presented and validate the proposed theoretical results.

  • ICRA - Visual Servoing from Spheres using a Spherical Projection Model
    Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007
    Co-Authors: Romeo Tatsambon Fomena, François Chaumette
    Abstract:

    In this paper, we investigate the use of a spherical projection model to search for optimal visual features for visual servoing. A new minimal set of three visual features is proposed for visual servoing from spheres using any central catadioptric system. Using this set of features, a classical control method is proved to be globally stable even in the presence of Modeling Error and locally stable to calibration Errors on perspective cameras. Using this type of cameras, experimental results are presented and validate the proposed theoretical results.

Abdulmotaleb El Saddik - One of the best experts on this subject based on the ideXlab platform.

  • robust control of four rotor unmanned aerial vehicle with disturbance uncertainty
    IEEE Transactions on Industrial Electronics, 2015
    Co-Authors: Shafiqul Islam, Abdulmotaleb El Saddik
    Abstract:

    This paper addresses the stability and tracking control problem of a quadrotor unmanned flying robot vehicle in the presence of Modeling Error and disturbance uncertainty. The input algorithms are designed for autonomous flight control with the help of an energy function. Adaptation laws are designed to learn and compensate the Modeling Error and external disturbance uncertainties. Lyapunov theorem shows that the proposed algorithms can guarantee asymptotic stability and tracking of the linear and angular motion of a quadrotor vehicle. Compared with the existing results, the proposed adaptive algorithm does not require an a priori known bound of the Modeling Errors and disturbance uncertainty. To illustrate the theoretical argument, experimental results on a commercial quadrotor vehicle are presented.

  • Nonlinear adaptive control for quadrotor flying vehicle
    Nonlinear Dynamics, 2014
    Co-Authors: Shafiqul Islam, Abdulmotaleb El Saddik
    Abstract:

    In this work, we deal with autonomous tracking and disturbance rejection problem of quadrotor vehicle flying in uncertain environment. The vehicles kinematic and Modeling Error uncertainties are associated with external disturbance, inertia, mass, and nonlinear aerodynamic forces and moments. The proposed method integrate the techniques from adaptive control and robust control theory. Robust and adaptive control algorithms for translational and orientation tracking are derived using Lyapunov method. It is shown in our analysis that the altitude, position, and attitude tracking Errors are bounded and their bounds asymptotically converge to zero in Lyapunov sense. Simulation results on a commercial quadrotor flying vehicle are given to demonstrate the effectiveness of theoretical arguments for real world application.

Roger Ghanem - One of the best experts on this subject based on the ideXlab platform.

  • reduced chaos decomposition with random coefficients of vector valued random variables and random fields
    Computer Methods in Applied Mechanics and Engineering, 2009
    Co-Authors: Christian Soize, Roger Ghanem
    Abstract:

    We develop a stochastic functional representation that is adapted to problems involving various forms of epistemic uncertainties including Modeling Error and data paucity. The new representation builds on the polynomial Chaos decomposition and eventually yields a Karhunen-Loeve expansion with random multiplicative coefficients. In this expansion, one set of uncertainty is captured in the usual manner, as uncorrelated scalar random variables. Another component of the uncertainty, statistically independent from the first, is captured by constructing the, usually deterministic, functions in the KL expansion as random functions. We think of the first set of uncertainties as associated with a coarse scale model, and of the second set as associated with subscale fluctuations not captured in the coarse scale description.

Hiroshi Fujimoto - One of the best experts on this subject based on the ideXlab platform.

  • proposal of state dependent minimum variance estimation of load side external torque considering Modeling and measurement Errors
    International Symposium on Industrial Electronics, 2018
    Co-Authors: Shota Yamada, Hiroshi Fujimoto
    Abstract:

    Sensorless external force/torque estimation is required for force/torque control in cooperative robots and human-support robots. Since the sensorless estimation suffers from Modeling Errors, we have proposed a novel load -side external torque observer, which has a gain determining the balance of the Modeling Error effects between the motor side and the transmission part in our previous study. This paper proposes a systematic design method of the gain determining the robustness based on the priori knowledge of the reliability of the plant parameters and the sensor measurements. The advantages of the proposed design method are validated by the simulations and experiments.

  • Minimum Variance Estimation of Load-side External Torque Using Load-side Encoder and Torque Sensor
    2018 57th Annual Conference of the Society of Instrument and Control Engineers of Japan (SICE), 2018
    Co-Authors: Shota Yamada, Hiroshi Fujimoto
    Abstract:

    Sensorless external force/torque estimation is required for force/torque control in cooperative robots and human-support robots. Our group has proposed a novel load-side external torque observer using load-side encoder information, which can reduce the measurement noise effects and Modeling Error effects of the motor side and the transmission part in our previous study. Based on the fact that most of the cooperative robots in industry have torque sensors, this paper proposes a load-side external torque observer using encoders' information and torque sensor's information for robust estimation against Modeling Errors and measurement noises. The advantages of the proposed observer are validated by the simulations and experiments.