A Digital Compensator Design for Electrohydraulic Single-Rod Cylinder Position Control Systems

Abstract

A digital compensator using a forward algorithm, F(z−1 ), and a feedback algorithm, H(z−1 ), is developed for an electrohydraulic position control system incorporating an underlapped servovalve and a single-rod cylinder. The main problems encountered with designing such a closed-loop system are discussed, and it is shown how the filter coefficients may be easily determined for a particular class of open-loop transfer function. An excellent comparison between theory and experiment is obtained and it is deduced that one coefficient only need be changed in the forward algorithm for such gain-change dominant systems.