A novel contour error compensator for 3-PRPS platform

Using a mathematical model to represent the nonlinear characteristics in dy namics of robot manipulators is rather difficult. To reduce the Cartesian s pace contour error, this study presents a novel contour error compensator i nfluenced by the parameter and unstructured uncertainties in robot manipula tors. The proposed compensator is based on the strategy of a Cartesian spac e cross-coupled control and the transform relations between Cartesian space and joint space. In addition, the joint space compensated control effort d erives reducing the Cartesian space contour error. Consequently, the contou r error can be reduced via the theoretical analysis. Moreover, a PC based, 3-PRPS platform control system is constructed to closely examine the effect s of the controller. Experiment results indicate that the controller can re duce the contour error as expected. Furthermore, the forward and the invers e kinematics are derived, along with the forward kinematics solved using th e numerical method. The work space of the platform is also described in a t hree-dimensional Cartesian space. (C) 2000 John Wiley & Sons, Inc.