A new time-delay compensation scheme for hydraulic systems

Operating delay time in the solenoid valves is common in the practical electro-hydraulic servo systems. This may sometimes cause closed-loop instability if it wasn't treated carefully in the control system designs. We propose 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; one is a fuzzy-PID controller used to ensure tracking performance, the other one is 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.