Hybrid Fuzzy PID Control of Hydraulic Robot

Abstract

This paper presents a fuzzy tracking control methodology for hydraulic control system of robot with generalized pulse modulation (GPCM) control by combining the merits of fuzzy logic and conventional linear control theory. The hydraulic control systems with GPCM control have the high nonlinearity and uncertain dynamics, therefore the simple linear or nonlinear differential equations cannot sufficiently represent corresponding practical system. The designed controllers based on the model cannot guarantee the good performance such as stability and robustness. A hybrid of fuzzy and PID control algorithm is proposed as the solution. The control algorithm is separated into two parts: fuzzy control and PID control. The fuzzy controller is used to control the piston when the piston is near the desired position, and PID controller is applied when the piston is far away the target position. The hybrid fuzzy PID is implemented on computer and applied to control the arms of hydraulic robot with GPCM control. The results from the experiments show that the proposed hybrid fuzzy PID control has good performance.