Position Control of Valve-Controlled Cylinder Based on CRL-DIARC

The control difficulties of electro-hydraulic system are high dynamic order, nonlinear model and uncertain model parameters. In order to achieve higher performance position control, it is necessary to design advanced nonlinear controller to ensure the control performance of the system. Aiming at the demand of high-precision position control of electro-hydraulic system particularly in scenarios with significant initial errors and complex disturbance, the state space equation of valve-controlled cylinder system is first established, and then the backstepping control framework is used to design the controller of the electro-hydraulic system. An exponential reaching law with constant velocity reaching compensation term sliding mode control method and integral sliding mode control method is used to construct the sliding surface and the direct/indirect adaptive robust control (DIARC) is used in each step of backstepping control, which developes DIARC with composite reaching law (CRL-DIARC). Finally, PID controller, DARC (direct adaptive robust control) controller, DIARC and CRL-DIARC controller are simulated and compared. The simulation results show that CRL-DIARC controller can effectively improve the position tracking performance of valve-controlled cylinders.