Intelligent Electro-Pneumatic Position Tracking System Using Improved Mode-Switching Sliding Control With Fuzzy Nonlinear Gain

Abstract

In this paper, a mode-switching sliding controller with the nonlinear gain generated by a fuzzy logic controller is put forward to enhance the tracking performance in an electro-pneumatic position control system which includes four solenoid ON-OFF valves and a double rod-end cylinder. The proposed method is designed to increase the response speed and reduce the overshoots by utilizing the nonlinear gain which is determined by a fuzzy logic controller. In addition, several improvements are made in the mode-switching sliding controller originally from previous works. The mode-switching strategy is totally redesigned and a hysteresis control scheme is introduced to the new mode-switching sliding controller. Moreover, the improved controller is properly combined with the fuzzy nonlinear gain. Simulation and experiments with various kinds of input are carried out to verify the effectiveness of the proposed method. All the experiments are conducted on a field programmable gate array platform, and the experimental results validate the reliability of the novel scheme.

Keywords

• Electro-pneumatic position control
• fuzzy logic control
• nonlinear gain
• ON–OFF valve
• sliding mode control