Electro-hydraulic servo system with predictive control

Propellent is a primary propulsive power source of the space navigation and missile weapon. In order to safely produce, transform and use it, its characteristics of friction sensitivity must be known very well. The results of test and analysis show that the precision of load force is the most important factor which affects the testing results profoundly. Considering the performance of the load system in which the asymmetric hydraulic cylinder is controlled by symmetrical electro-hydraulic proportional valve, load flow of hydraulic is newly defined in the paper. On this basis, the mathematical model of the electro-hydraulic proportional servo force control system is then established. The great volume and friction of cylinder make the system have pure time delay, traditional PID strategy can not satisfy the control qualification in the load system, a Smith predictive controller is designed and used in the control system. Results of simulation and experiments demonstrate that strong robustness and high precision are obtained in applications.