Abstract: A new tuning method of constant PID parameters for parallel manipulator is investigated. Considering the mechatronics coupling, characteristics of the whole workspace and variable inertia load along with the pose, three trajectories with different weights are selected. Then inverse kinematics and inverse dynamic model are set up by using vector method and virtual power principle. Making the minimized following trajectory errors of end effector as optimized goal, the controller parameters could be tuned. An example is adopted with one parallel manipulator-Diamond which is developed by Tianjin University, and the values of controller parameters can be given according to the above theory. The problem that the multiobjective functions contradict each other is also solved. At last, a series of experiments are done for validating the correctness and validity of the theory.

Key words: Parallel manipulator, Parameter tuning, Servo system, average integral optical density, digital image processing, grinding blade dihedral angle, integral optical density, optical density, polyhedral abrasive grains