The Experts below are selected from a list of 21540 Experts worldwide ranked by ideXlab platform

Wenjie Dong - One of the best experts on this subject based on the ideXlab platform.

Jeanjacques E Slotine - One of the best experts on this subject based on the ideXlab platform.

  • decentralized adaptive control for collaborative manipulation of rigid bodies
    IEEE Transactions on Robotics, 2021
    Co-Authors: Preston Culbertson, Jeanjacques E Slotine, Mac Schwager
    Abstract:

    In this work, we consider a group of robots working together to manipulate a rigid object to track a Desired Trajectory in $\text{SE}(3)$ . The robots do not know the mass or friction properties of the object, or where they are attached to the object. They can, however, access a common state measurement, either from one robot broadcasting its measurements to the team, or by all robots communicating and averaging their state measurements to estimate the state of their centroid. To solve this problem, we propose a decentralized adaptive control scheme wherein each agent maintains and adapts its own estimate of the object parameters in order to track a reference Trajectory. We present an analysis of the controller’s behavior, and show that all closed-loop signals remain bounded, and that the system Trajectory will almost always (except for initial conditions on a set of measure zero) converge to the Desired Trajectory. We study the proposed controller’s performance using numerical simulations of a manipulation task in 3-D, as well as hardware experiments which demonstrate our algorithm on a planar manipulation task. These studies, taken together, demonstrate the effectiveness of the proposed controller even in the presence of numerous unmodeled effects, such as discretization errors and complex frictional interactions.

  • decentralized adaptive control for collaborative manipulation of rigid bodies
    arXiv: Robotics, 2020
    Co-Authors: Preston Culbertson, Jeanjacques E Slotine, Mac Schwager
    Abstract:

    In this work, we consider a group of robots working together to manipulate a rigid object to track a Desired Trajectory in $SE(3)$. The robots have no explicit communication network among them, and they do no know the mass or friction properties of the object, or where they are attached to the object. However, we assume they share data from a common IMU placed arbitrarily on the object. To solve this problem, we propose a decentralized adaptive control scheme wherein each agent maintains and adapts its own estimate of the object parameters in order to track a reference Trajectory. We present an analysis of the controller's behavior, and show that all closed-loop signals remain bounded, and that the system Trajectory will almost always (except for initial conditions on a set of measure zero) converge to the Desired Trajectory. We study the proposed controller's performance using numerical simulations of a manipulation task in 3D, and with hardware experiments which demonstrate our algorithm on a planar manipulation task. These studies, taken together, demonstrate the effectiveness of the proposed controller even in the presence of numerous unmodelled effects, such as discretization errors and complex frictional interactions.

  • approximate jacobian adaptive control for robot manipulators
    International Conference on Robotics and Automation, 2004
    Co-Authors: Chien Chern Cheah, Chao Liu, Jeanjacques E Slotine
    Abstract:

    Research so far on Trajectory tracking control of robot has assumed that the kinematics of the robot is known exactly. In this paper, a new approximate Jacobian adaptive controller is proposed for Trajectory tracking of robot with uncertain kinematics and dynamics. It is shown that the robot end effector is able to converge to a Desired Trajectory with the uncertain kinematics and dynamics parameters being updated online by parameter update laws. Experimental results are presented to illustrate the performance of the proposed controllers.

Eric Rogers - One of the best experts on this subject based on the ideXlab platform.

  • Trajectory Tracking Control for Autonomous Underwater Vehicles Based on Fuzzy Re-Planning of a Local Desired Trajectory
    IEEE Transactions on Vehicular Technology, 2019
    Co-Authors: Xing Liu, Mingjun Zhang, Eric Rogers
    Abstract:

    This paper investigates the Trajectory tracking control problem for autonomous underwater vehicles whose initial starting position differs substantially from that specified by the Desired Trajectory. This scenario is very likely to cause serious chattering in the control output, especially in the early stages, when the large tracking error is the input to the controller. A novel Trajectory tracking control strategy is developed based on fuzzy re-planning of a local Desired Trajectory. At each time instant, a local Desired Trajectory is reconstructed based on the AUV's current position and that specified by the original Desired Trajectory at a future time. Also the control effort is computed based on the local Desired Trajectory, rather than the original one. Moreover, the interval between each time instant is determined by a new single-input fuzzy model, where the input is determined by the distance between AUV's current and Desired trajectories and the change in the distance. Finally, the effectiveness of the new control strategy is verified by simulation-based case studies using an actual vehicle model as a necessary step prior to experimental validation.

John Hauser - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Trajectory tracking control for wind turbines during operating region transitions
    2013 American Control Conference, 2013
    Co-Authors: John Hauser
    Abstract:

    Control systems for wind turbines have become an active area of research over the past decade as the wind industry has grown and more turbines are installed. Properly sited turbines experience many transitions between below rated operation, where the goal is to extract maximum energy from the wind, and rated speed operation, where the goal is to regulate the power capture to the rated power of the turbine. Many of the largest structural loads are induced during the transition between these operating regions. This paper focuses on using preview wind speed measurements to schedule, optimize, and track a Desired Trajectory of the wind turbine states and inputs during region transitions between below-rated and above-rated operation. The goal of this control system is to reduce the structural loading on the turbine components through smoother region transitions. The wind speed preview measurements are used to generate an initial Desired Trajectory of the turbine. This Trajectory is optimized by finding a regulation Trajectory that lies on the turbine Trajectory manifold which is close to the Desired Trajectory in a weighted L2 sense. The regulation Trajectory is then used as a reference for a time-varying linear quadratic optimal controller.

Liu Yanzhu - One of the best experts on this subject based on the ideXlab platform.

  • the robust control scheme for free floating space manipulator to track the Desired Trajectory in jointspace
    Acta Mechanica Solida Sinica, 2001
    Co-Authors: Liu Yanzhu
    Abstract:

    The control of a free-floating space manipulator system is discussed. With the augmentation approach, the nonlinear parameterization problem of the dynamic equations of the space manipulator system is overcome. Based on the results, the robust control scheme for free-floating space manipulator with uncertain payload parameters to track the Desired Trajectory in jointspace is proposed, and the global convergence of the tracking is verified by using the Laypunov method. The proposed control scheme is computationally simple, because we choose to make the controller robust to the uncertain inertial parameters rather than explicitly estimate them online. In particular, it needn't control the position and attitude of the floating base. A two-link planar space manipulator system is simulated to verify the control scheme proposed.

  • robust adaptive control for free floating space manipulator to track Desired Trajectory in jointspace
    Chinese Quarterly of Mechanics, 2001
    Co-Authors: Liu Yanzhu
    Abstract:

    In this paper, the control problem of free-floating space manipulator system with uncertain parameters was studied. Because the base of space manipulator is not controlled and it is free-floating, the dynamic equations of space manipulator system no longer be linearly parameterized. It results the control of space manipulator system becomes very difficult. Based on the idea of augmentation approach, the difficulty proposed above is overcome, and the robust adaptive control scheme for space manipulator to track the Desired Trajectory in jointspace was developed. The asymptotic stability of the control scheme was proved with Lyapunov method. The proposed control scheme can be applied to the design of the control system of manipulator used in the cabin. A two-link planar space manipulator system is simulated to verify the proposed control scheme.

  • dynamic and variable structure control for space manipulator to track Desired Trajectory in workspace
    Chinese Quarterly of Mechanics, 2000
    Co-Authors: Liu Yanzhu
    Abstract:

    In this paper, the kinematics and dynamics of free-floating space manipulator systems are analyzed. By use of the method of multibody dynamics, the dynamic equations and the kinematic Jacobi relationship of space manipulator are established. Based on the results, the control problem for space manipulator to track the Desired Trajectory in workspace is discussed. Because of the high structure complexity and the parameter uncertainty of space manipulator systems, the scheme of variable structure control with better robustness to uncertainty and disturbance is proposed. The advantages of the control scheme proposed are that it needn' t to control the position and attitude of the base. To show the feasibility of the proposed control scheme, a simulation study of three-link planar space manipulator system is presented .