A New Time-Delay Compensating Scheme for Electro-Hydraulic Systems

Abstract

Operating time delay in the solenoid valves is very common for practical electro-hydraulic servo systems. It may sometimes cause performance degradation or even instability if it isn't treated carefully during control system designs. We propose in this paper a non-model-based design approach for hydraulic actuating systems based on a new time-delay compensation scheme. In the proposed system, two types of controllers are combined: a fuzzy-PID controller used to ensure primary tracking performance and an adaptable wavelet compensator used to compensate for the time delay resulting from the control valve. Performance of the proposed design is widely verified on a newly developed simulation platform to show its effectiveness.

Keywords:

• hydraulic system
• position control
• time-delay
• fuzzy control
• wavelet neural network