Nonovershooting position control for unidirectional proportional pump controlled asymmetric cylinder with proportional controller

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 one-way flow control ability of the unidirectional proportional pump makes the problem more complex. To realize the nonovershooting position control and simplify the system analysis and synthesis, this paper presented a third order mathematic model to depict the dynamic behavior of the unidirectional proportional pump-controlled asymmetric cylinder. A specially designed proportional controller is used to guarantee that the step response of the system is nonovershooting, and that the system performance can be analyzed with the classic linear control theory. Based on the condition of stability, the index of stable error and the condition of the third order system´s nonovershooting step response, a numerical algorithm for nonovershooting proportional gain determining is given. The experiments are carried out, and the results show that the proposed method is valid.