Designing low-chattering sliding mode controller for an electrohydraulic system

Sliding mode controllers of first and second orders have been designed for linear motion tracking for an eletrohydraulic actuation system having deadband and other nonlinear features like cylinder stiction, hysterisis and Stribeck characteristics. An input linearized structure has been developed to formulate sliding mode controllers, or SMC, of orders 1 and 2 for the nonlinear system. The applied SMC is coupled with a simple integral compensator for attenuating both the chatter of the input signal and any steady state error of the output. Real-time experiments have been carried out that show the first-order controller as better above 1.4Hz tracking and the second-order controller as better below 1.4Hz.