Dynamic Compensation for the Deadzone of the Electro-hydraulic Proportional Position Servo Control System

摘要

The valve-controlled motor eletrohydraulic proportional servo system driving static loadtorque has severe time-varying deadzone and gain nonlinearities in the presence of the load torquevariations. An experimental comparison study was made between several control methods. Experimentalresults show that the high gain control causes instability; the integral control aggravates stick slip andintroduces hunting; the fixed deadzone compensation greatly reduces the positioning error when the loadtorque is a constant, but it causes poor positioning accuracy when the load torque varies greatly. Thedynamic deadzone compensation based on the error e(t) and error-in-change ?e(t) can significantlyimprove the positioning precision over a wide range of load torque.