An Intelligent Electro-Hydraulic Servo Drive Positioning

The goal of the research is to develop a closed loop control system for position control of electrohydraulic servo drive useful for practical application. The research was performed based on the theory of adaptive feedback systems. The proposed new control structure consists of three parts. The first part is actually a feed-forward digital filter in the form of an inverse model of the system, which enables a perfect reference tracking behaviour. The second part is a position feedback fuzzy logic controller designed as a self-learning system, which possesses an ability of automatic tuning and is able to cope with parameter and load changes of the control loop. The third part is the so called switching integrator involved to improve steady state errors and ensure precise final positioning. The effectiveness is proven by laboratory experimental investigations.