Analysis of Nonlinear PID Controller for Tracking Performance of Ball Screw Drive

Abstract

In control system industry, it is crucial to have good tracking performance at higher speed. However, cutting force disturbances in machining affect the performance. Therefore, a good controller is important to compensate the disturbances. The focus area in this paper is to evaluate the tracking performance of Nonlinear PID (NPID) controllers based on two conditions. The first condition is based on a bounded nonlinear gain, K(e) and secondly is based on constructing two parameters of integral controlled quantity, Ui and differential control efficient, Kd. The performance measures for this research are 10mm for every 0.4Hz and 0.7Hz of reference input to evaluate the tracking performance of the controllers. This research focuses on the comparison of two sets of the condition of NPID controllers for x-axis of ball screw drive. There are three analyses to classify the performances; maximum tracking error, root means square error (RMSE) and error reduction. The results show that NPID based on a bounded nonlinear gain K(e) has better tracking performance than NPID based on Ui and Kd. NPID controller (K(e) based) successfully reduced 33%-37% of error compared to NPID controller (Ui and Kd based). The designed controllers can have an adaptive algorithm to improve the adaptation of the controllers to the system as the recommended purposes.