Research On The Control Method Of The Serial Type Pump-Value Coordinated Electro-Hydraulic Servo System

The electro-hydraulic servo system has been widely used in industrial application since its fast response and highest control accuracy. However, The efficiency of electro-hydraulic servo system is low because of its throttling principle,causing great loss in energy, having been restricted in many fields for its further applications and going against the trend of green sustainable development.In order to improve the efficiency of electro-hydraulic servo system, this paper will study Pump-valve coordinated control to balance between the high performance of valve control system and the high efficiency of pump control system. Finally, this paper chooses the serial type pump-value coordinated electro-hydraulic servo system.The control strategy of the serial type pump-value coordinated electro-hydraulic servo system is studied. The flow-adaptive and time-interval control strategy as well as pressure-adaptive and time-interval control strategy is put forward to meet the flow and pressure of the load.The system mathematical model of the serial type pump-value coordinated electro-hydraulic servo system will be built in this paper to research its properties and the influence of the changes of the system parameters on the value-control system. The conclusion will be brought forth, which will reveal that the changes of system parameters effects directly the open loop gain and stability of value-control system.According to the conclusion, the control strategy of the value-control system will be further studied. The Hinf robust and self-adaptive controller will be designed in this paper.The MIT self-adaptive control algorithm exist defect, which is liable to failure due to the initial state of value-control system. According to the defect of the MIT self-adaptive control algorithm, the system pressure will be measured to give a initial value to the MIT self-adaptive control algorithm. And the saturated integrator will be used. The simulation of the Hinf robust and self-adaptive controller will be implemented to verify the control effect.The system parameters will be identified to obtain mathematical model. The PID controller, the Hinf robust controller, Hinf robust with self-adaptive controller and the modified Hinf robust with self-adapative controller will be designed based on themathematical model of value-control system. The experiment will be implemented based on the XPC Target Real-time simulation environment to verify the control effect of these controller.Experimental results show that the modified Hinf robust with self-adapative controller which coping with the Perturbation model has the same control effect with the Hinf robust controller which coping with the nominal model.The experiment shows that the modified Hinf robust with self-adapative controller has the better stability, the comparatively strong robust and the ability of restrain disturbing.The experimental results indicate that the modified Hinf robust with self-adapative controller is perfect for the serial type pump-value coordinated electro-hydraulic servo system thanks to effect is excellent.