Nonlinear dynamic analysis and control of a hydraulic press electro-hydraulic servo system

Abstract

The internal electro-hydraulic servo system of a hydraulic press is affected by the non-linear friction, and it becomes non-linear, unstable under vibration. In this study, the dynamic behavior and control of such a system were investigated. A mathematical model was first built and then proportional-integral-derivative control and sliding mode control were applied. Particle swarm optimization was used to find the optimal gain values and proportional-integral-derivative control parameters to control and stabilize the system. Sliding mode control was used for interactive comparison to demonstrate that the controller could avert chaos and restore stable periodic motion. A circuit was designed and assembled for the experimental confirmation of the results. The results showed that control of nonlinear behavior was better with sliding mode control than proportional-integral-derivative. This study can serve as a reference for the further investigation of hydraulic press electro-hydraulic servo systems.