Research On Passive Electric Hydraulic Servo System Of The Valve Control Oscillation Motor

Passive electric hydraulic servo system is a kind of hardware-in-the-loop simulation equipment which is used to simulate the load torque of aircraft during the flight under the experimental conditions. The system is a typical electro-hydraulic load simulator. With the change of world situation, and the more important of national defense construction, higher requirements to the torque loading’s precision and dynamic frequency response of passive electric hydraulic servo system are raised. In this paper, passive electric hydraulic servo system is analyzed and researched deeply. Meanwhile, the control strategy which improved the control performance of the system is proposed.In the paper, the composition and working principle of the passive electric hydraulic servo system are expounded and two mathematical models are set up basing on the mechanism modeling method. By comparing the two methods, precise mathematical model is selected as a basis to analyze the control system. The reason that impacts the generation of surplus torque is found through analyzing the mathematical model. To eliminate surplus torque’s effect on the system, traditional linear PID controller is used to improve the tracking precision. A new compensation structure is put forward by comparing the different common compensation methods which bases on feed-forward compensation principle. Through simulation analysis, this compensation structure can well restrain the interference of surplus torque and reduce the differential order of compensation link which is easy to implement in physical. To dispel the difficulty of parameter adjustment under the PID control and the limitations of application in the small loading gradient, a new optimal predicted controller based on the information optimal fusion estimation theorem is designed. By comparing the simulations, the tracking precision and the inhibition effect of surplus torque have been further improved. Meanwhile, the effectiveness of this method is validated. Combined with the designed hardware circuit and software of control system, the experimental platform is set up which is used to verify the designed control method. Experimental results show that all indicators of the system meet the design requirement. Also, it is further verified that the accuracy and effectiveness of this control system.