Study on High Accuracy Control System for a Hybrid Seven-Bar Actuator

Hybrid seven bar actuator is a typical planar parallel robot. It remains with position control following system. Position control accuracy of system determines the profile accuracy of hybrid actuator. According to the characteristics of the hybrid seven bar actuator, incorporating the grey prediction, repetitive control and the conventional PID control, a design method of the Grey prediction Repetitive PID control algorithm (GRPID) is presented for the first time. The hybrid control algorithm can estimate unsure parameters and disturbance of system using grey prediction, and compensate control in terms of the prediction results, and this may improve control quality and robustness of repetitive control for controlling periodic motion. The simulation results show that this algorithm has better performances than that of the conventional repetitive control system. It indicates the control method has better application effect for hybrid actuator taking on a characteristic of periodic motion.