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Clément Gosselin - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic Point-To-Point Trajectory Planning for Three Degrees-of-Freedom Cable-Suspended Parallel Robots Using Rapidly Exploring Random Tree Search
    Journal of Mechanisms and Robotics, 2020
    Co-Authors: Xiang Sheng, Haibo Gao, Zhen Liu, Clément Gosselin
    Abstract:

    Abstract This paper proposes a dynamic Point-to-Point Trajectory planning technique for three degrees-of-freedom (DOFs) cable-suspended parallel robots. The proposed technique is capable of generating feasible multiple-swing trajectories that reach Points beyond the footprint of the robot. Tree search algorithms are used to automatically determine a sequence of intermediate Points to enhance the versatility of the planning technique. To increase the efficiency of the tree search, a one-swing motion primitive and a steering motion primitive are designed based on the dynamic model of the robot. Closed-form expressions for the motion primitives are given, and a corresponding rapid feasibility check process is proposed. An energy-based metric is used to estimate the distance in the Cartesian space between two Points of a dynamic Point-to-Point task, and this system’s specific distance metric speeds up the coverage. The proposed technique is evaluated using a series of Monte Carlo runs, and comparative statistics results are given. Several example trajectories are presented to illustrate the approach. The results are compared with those obtained with the existing state-of-the-art methods, and the proposed technique is shown to be more general compared to previous analytical planning techniques while generating smoother trajectories than traditional rapidly exploring randomized tree (RRT) methods.

  • dynamic Point to Point Trajectory planning of a three dof cable suspended mechanism using the hypocycloid curve
    IEEE-ASME Transactions on Mechatronics, 2018
    Co-Authors: Pascal Diongauvin, Clément Gosselin
    Abstract:

    This paper proposes a dynamic Trajectory planning technique for the Point-to-Point motion of three-degree-of-freedom cable-suspended mechanisms. The Trajectory path is inspired from a hypocycloid curve that is embedded in the plane defined by the acceleration vector at the initial Point and the final Point. The proposed motion ensures zero instantaneous velocity at each of the endPoints and continuity of the acceleration, while positive cable tensions are guaranteed through a proper choice of the number of arcs of the hypocycloid. The Trajectory can be used in sequence to connect consecutive target Points that may lie beyond the static workspace of the mechanism. Compared to previously proposed approaches, the technique developed in this paper produces very large regions of attainable target Points. In particular, it is proven that horizontal trajectories are always feasible, for any prescribed target Point. Simulation results of an example Trajectory are included in order to illustrate the approach, along with a video demonstration of an experimental validation performed using a prototype.

  • Dynamic Point-to-Point Trajectory Planning Beyond the Static Workspace for Six-DOF Cable-Suspended Parallel Robots
    IEEE Transactions on Robotics, 2018
    Co-Authors: Xiaoling Jiang, Eric Barnett, Clément Gosselin
    Abstract:

    This paper proposes a Point-to-Point dynamic Trajectory planning technique for reaching a series of poses with a six-degree-of-freedom (six-DOF) cable-suspended parallel robot. Each Trajectory segment is designed to have zero translational and rotational velocity at its endPoints; transitions between segments have translational and rotational acceleration continuity. This formulation facilitates the synthesis of trajectories that extend beyond the static workspace of the robot. A basis motion is introduced, which is a mathematical function that can be adapted for each coordinate direction along each Trajectory segment. Kinematic constraints are satisfied through the selection of the coefficients for this function. Dynamic constraints are imposed by defining feasible regions within the workspace for each segment endPoint, based on the previous endPoint. Spherical linear interpolation (SLERP) is used to produce singularity-free, optimally interpolated rotational Trajectory segments. An experimental implementation is presented using a six-DOF prototype and a supplementary video file is included to demonstrate the results.

  • dynamic Point to Point Trajectory planning of a three dof cable suspended parallel robot
    IEEE Transactions on Robotics, 2014
    Co-Authors: Clément Gosselin, Simon Foucault
    Abstract:

    This paper presents two Trajectory-planning approaches for the Point-to-Point motion of planar two-degree-of-freedom (dof) cable-suspended parallel mechanisms. The proposed techniques can be used to plan trajectories that extend beyond the static workspace of the mechanism. Trajectories are specified as a list of target Points that must be reached in sequence, with a zero velocity at each of the target Points. In the first technnique, polynomial trajectories are designed to connect the target Points, while the second approach uses trigonometric functions. Both techniques ensure continuity of the accelerations. Based on the dynamic model of the robot, algebraic inequalities are obtained that represent the constraints on cable tensions. These inequalities are used to determine the feasibility of the planned trajectories. Polynomial trajectories must be discretized in order to verify feasibility, while trajectories that are based on trigonometric functions can be verified globally, based on a set of simple algebraic equations. Example trajectories are given in order to illustrate the approach. An experimental validation is also presented using a two-dof prototype, and two video extensions are provided to demonstrate the results.

Sunil K Agrawal - One of the best experts on this subject based on the ideXlab platform.

  • differential flatness based planning and control of a wheeled mobile manipulator theory and experiment
    IEEE-ASME Transactions on Mechatronics, 2011
    Co-Authors: Chin Pei Tang, P T Miller, Venkat Krovi, Sunil K Agrawal
    Abstract:

    This paper presents a differential-flatness-based integrated Point-to-Point Trajectory planning and control method for a class of nonholonomic wheeled mobile manipulator (WMM). We demonstrate that its kinematic model possesses a feedback-linearizable description due to the flatness property, which allows for full-state controllability. Trajectory planning can then be simplified and achieved by polynomial fitting method in the flat output space to satisfy the terminal conditions, while control design reduces to a pole-placement problem for a linear system. The method is then deployed on our custom-constructed WMM hardware to evaluate its effectiveness and to highlight various aspects of the hardware implementation.

Simon Foucault - One of the best experts on this subject based on the ideXlab platform.

  • dynamic Point to Point Trajectory planning of a three dof cable suspended parallel robot
    IEEE Transactions on Robotics, 2014
    Co-Authors: Clément Gosselin, Simon Foucault
    Abstract:

    This paper presents two Trajectory-planning approaches for the Point-to-Point motion of planar two-degree-of-freedom (dof) cable-suspended parallel mechanisms. The proposed techniques can be used to plan trajectories that extend beyond the static workspace of the mechanism. Trajectories are specified as a list of target Points that must be reached in sequence, with a zero velocity at each of the target Points. In the first technnique, polynomial trajectories are designed to connect the target Points, while the second approach uses trigonometric functions. Both techniques ensure continuity of the accelerations. Based on the dynamic model of the robot, algebraic inequalities are obtained that represent the constraints on cable tensions. These inequalities are used to determine the feasibility of the planned trajectories. Polynomial trajectories must be discretized in order to verify feasibility, while trajectories that are based on trigonometric functions can be verified globally, based on a set of simple algebraic equations. Example trajectories are given in order to illustrate the approach. An experimental validation is also presented using a two-dof prototype, and two video extensions are provided to demonstrate the results.

Chin Pei Tang - One of the best experts on this subject based on the ideXlab platform.

  • differential flatness based planning and control of a wheeled mobile manipulator theory and experiment
    IEEE-ASME Transactions on Mechatronics, 2011
    Co-Authors: Chin Pei Tang, P T Miller, Venkat Krovi, Sunil K Agrawal
    Abstract:

    This paper presents a differential-flatness-based integrated Point-to-Point Trajectory planning and control method for a class of nonholonomic wheeled mobile manipulator (WMM). We demonstrate that its kinematic model possesses a feedback-linearizable description due to the flatness property, which allows for full-state controllability. Trajectory planning can then be simplified and achieved by polynomial fitting method in the flat output space to satisfy the terminal conditions, while control design reduces to a pole-placement problem for a linear system. The method is then deployed on our custom-constructed WMM hardware to evaluate its effectiveness and to highlight various aspects of the hardware implementation.

Gwitae Park - One of the best experts on this subject based on the ideXlab platform.

  • zero moment Point Trajectory modelling of a biped walking robot using an adaptive neuro fuzzy system
    IEE Proceedings - Control Theory and Applications, 2005
    Co-Authors: Dongwon Kim, Samjun Seo, Gwitae Park
    Abstract:

    A bipedal architecture is highly suitable for a robot built to work in human environments since such a robot will find avoiding obstacles a relatively easy task. However, the complex dynamics involved in the walking mechanism make the control of such a robot a challenging task. The zero-moment Point (ZMP) Trajectory in the robot's foot is a significant criterion for the robot's stability during walking. If the ZMP could be measured on-line then it becomes possible to create stable walking conditions for the robot and here also stably control the robot by using the measured ZMP, values. ZMP data is measured in real-time situations using a biped walking robot and this ZMP data is then modelled using an adaptive neuro-fuzzy system (ANFS). Natural walking motions on flat level surfaces and up and down a 10/spl deg/ slope are measured. The modelling performance of the ANFS is optimized by changing the membership functions and the consequent part of the fuzzy rules. The excellent performance demonstrated by the ANFS means that it can not only be used to model robot movements but also to control actual robots.

  • fuzzy modeling of zero moment Point Trajectory for a biped walking robot
    International Conference on Knowledge-Based and Intelligent Information and Engineering Systems, 2004
    Co-Authors: Dongwon Kim, Nak Hyun Kim, Samjun Seo, Gwitae Park
    Abstract:

    The biped walking robot has almost the same mechanisms as a human and is suitable for moving in an environment which contains stairs, obstacles, etc. However, the complex dynamics involved make the biped robot control a challenging task. For the stability of the biped walking robot, the zero moment Point (ZMP) Trajectory in the robot foot support area is a significant criterion. If the ZMP during walking can be measured, it is possible to realize stable walking and to stably control the biped robot by the use of the measured ZMP. In this paper, actual ZMP data are measured in real time situations from practical biped walking robot and the obtained ZMP data are modeled by TS-type fuzzy system. By the simulation results, the TS-type fuzzy system can be effectively used to model practical biped walking robot.