Modelling and simulation of unidirectional proportional pump-controlled asymmetric cylinder position control system with model predictive control algorithm

Unidirectional proportional pump-controlled asymmetric cylinder systems are widely used on industry machines, but the analysis and synthesis of such systems is very hard due to the nonlinearity caused by the different working areas of cylinder piston. The limit of one-way flow control ability of the pump and the working pressure make the problem more complex. It is very hard to find an effective method to solve this problem with the existing theory of electro-hydraulic servo control. To simplify the analysis and realize the no overshooting position control, this paper presents a third order state-space model with input and output constraints to depict the dynamic behavior of the system. A specially designed model predictive controller is used to guarantee that the output of the system has no overshooting. The results of the simulation experiments show that the proposed method can realize the high precision position control under multiple constraints effectively.