Adaptive Control of Electrohydraulic Servo System

Electro hydraulic servo system, one of the important drive systems in industrial sector as it possess some merits such as high power to weight ratio, precise and fine control, small size, good load matching, high environmental stiffness, fast dynamic performances and wide adjustable speed range. It can be angular displacement, velocity or force control system depending on variable to be controlled. The objective of Adaptive Control is to achieve and to maintain acceptable level of performance when plant model parameters are unknown or vary. The system considered for the study consists of a hydraulic motor as actuator with a load attached to its shaft. The dynamics of hydraulic systems are highly nonlinear and make control design for precise output tracking very challenging. Also the hydraulic parameters may vary due to temperature changes and external load, friction, and noise effects result in unacceptable tracking errors. In this paper, A Model reference adaptive control with feed forward configuration is implemented in the system. Simulation results are presented to show the performance of Model Reference Adaptive Control (MRAC) with feedforward configuration