Study and implementation on high accuracy servo system for robot joint

Abstract

In the industrial application, robot joint is required to satisfy the measures of performance of fast response speed, running stably and high accuracy. Torque-ripple control of the motor and the position controller are the main issue of the high accuracy servo drive systems. At first in this paper, relationship of duty cycle value, back EMF and torque is analyzed, and a way based on off-line back EMF is introduced to eliminate torque ripple. Then as for the high accuracy position servo control system in the control system, this paper designs a fuzzy adaptive PID controller to track position trajectories, and presents the principle and composition of the controller. The method can reduce the overflow of system output and improve the speed of reaching stability state in system. Experimental results based on a single-chip microcomputer XC167CI control system and a power MOSFET inverter-fed motor drive system are presented to illustrate the effectiveness of the proposed method for the control. Finally, the general controller is applied into the inspection robot used for power transmission line, which can achieve satisfactory performances.