摘要:

AbstractThis article presents two new adaptive schemes for the motion control of robot manipulators. The proposed controllers are very general and computationally efficient because they do not require knowledge of either the mathematical model or the parameter values of the manipulator dynamics, and are implemented without calculation of the robot inverse dynamics or inverse kinematic transformation. It is shown that the control strategies are globally stable in the presence of bounded disturbances, and that in the absence of disturbances the ultimate bound on the size of the tracking errors can be made arbitrarily small. Computer simulation results are given for a PUMA 560 manipulator, and demonstrate that accurate and robust trajectory tracking can be achieved by using the proposed controllers. Experimental results are presented for an IMI Zebra Zero manipulator and confirm that the control schemes provide a simple and effective means of obtaining high‐performance trajectory tracking. © 1995 John Wiley&Sons, I

ISSN:0741-2223    

DOI:10.1002/rob.4620120802

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe mathematical formulation of optimal trajectory planning for a space robot docking with a moving target is derived. The calculus of variations is applied to the problem so that the optimal robot trajectory can be obtained directly from the target information without first planning the trajectory of the end‐effector. The nonlinear two‐point boundary value problem resulting from the problem formulation is solved numerically by a globally convergent homotopy algorithm. The algorithm guarantees convergence to a solution for an arbitrarily chosen initial guess. Numerical simulation for three examples demonstrates the approach. © 3995 John Wiley&Sons,

ISSN:0741-2223    

DOI:10.1002/rob.4620120803

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSeveral authors have noted that if the robot inertia matrix D(q) can be factored as NT(q)N(q) where N(q) is the Jacobian of a function Q(q), then Q and P = N(q)q define a canonical transformation relative to which the robot dynamics are linear except for gravity terms. In this article, we show that necessary and sufficient condition for the existence of such a factorization is that the Riemannian curvature of the robot inertia matrix D(q) vanish identically. We use this result to generate feedback linearization and approximate feedback linearization control laws that require fewer calculations than the usual method of computed torque. © 1995 John Wiley&Sons, Inc

ISSN:0741-2223    

DOI:10.1002/rob.4620120804

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSolving current formulations of the time‐optimal point‐to‐point motion problem for robotic manipulators is a computationally intensive task. Thus, most existing solutions are not suitable for on‐line motion planning applications, such as the interception of moving targets, where time‐optimality of the motion is advantageous. A novel technique is proposed in this article that separates the time‐optimal point‐to‐point motion problem into the following two sub‐problems: (1) selection of a near‐time‐optimal path between the two endpoints, and (2) generation of time‐optimal motion along the selected path (i.e., constrained continuous path motion). Although our approach uses known path‐constrained time‐optimal‐motion algorithms for the second sub‐problem, a new method is proposed for the selection of near‐time‐optimal paths. Based on a study of the characteristics of global‐time‐optimal paths, the near‐optimal path is selected as a minimum‐curvature joint spline, tangent to one of the manipulator's acceleration directions at the start point, and tangent to the required manipulator velocity direction at the end point. The algorithm for determining the overall near‐optimal path is described herein, along with an example. Simulation test results and computation‐time studies indicate that the proposed method is suitable for on‐line motion p

ISSN:0741-2223    

DOI:10.1002/rob.4620120805

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe number of the control actuators used by the inverse kinematics and dynamics algorithms that have been developed in the literature for generating redundant robot joint trajectories is equal to the number of the degrees of freedom of the manipulator. In this article, an inverse dynamics algorithm that performs the tasks using only a minimum number of actuators is proposed. The number of actuators is equal to the dimension of the task space, and the control forces are solved simultaneously with the corresponding system motion. It is shown that because all degrees of freedom are not actuated, the control forces may lose the ability to make an instantaneous effect on the end‐effector acceleration at certain configurations, yielding the dynamical equation set of the system to be singular. The dynamical equations are modified in the neighborhood of the singular configurations by utilizing higher‐order derivative information, so that the singularities in the numerical procedure are avoided. Asymptotically stable inverse dynamics closed‐loop control in the presence of perturbations is also discussed. The algorithm is further generalized to closed chain manipulators. Three‐link and two‐link redundant planar manipulators are analyzed to illustrate the validity of the approach. © 2995 John Wiley

ISSN:0741-2223    

DOI:10.1002/rob.4620120806

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:0741-2223    

DOI:10.1002/rob.4620120801

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY