Steering Gear Dynamic Loading System Control Simulation Study

The rudder dynamic loading system is simulative equipment simulating the aerodynamic torque loads on the flight vehicle under laboratory conditions. It is used to detect and check all kinds of performance index of the rudder driving system, such as dynamic performances, control precision, system reliability etc. With the development of national defense industry, not only the demand for loading simulator is growing, but also the request of its technical index become higher. The object of research is electrical torque loading simulator. Because it is a kind of typical passive torque loading system, it is inevitable that large surplus torque will be caused by strong disturbance of rudder displacement. Furthermore, since its actuator is permanent magnet DC servo motors, it has many unique characteristics comparing with electro-hydraulic loading simulator. Aiming at special and general problems of the motor torque loading simulator, this dissertation puts forward effective control methods to improve the system performancesAfter summarizing the basic operational principle and development of load simulator, it turns out that the key problem of loading simulator is eliminating the surplus torque. Then the mathematical model of loading simulator is established and the static and dynamic performance is analyzed in detail. Differential forward PID is introduced to improve frequency band and structure invariance principle to eliminate surplus torque. Good compensation effect can be learned from linear constant system. In the dissertation, the nonlinear ingredients of loading system are analyzed. It is obvious that the conventional control method can not solve those problems. In Chapter IV, according to the learning characteristic and the function approximation ability of neural network, a hybrid control scheme based on speed feed-forward control is proposed. The simulation results showed that the hybrid controller could improve the dynamic loading performances fairly through identification and control. Adaptive sliding mode variable structure control method was applied to load simulator in Chapter V. Sliding mode variable structure control is a nonlinear control method that is complete independence on sliding mode and disturbance outside together with parameter vibration. The control arithmetic is simple and convergent in the whole. The simulation result shows that the scheme improves the dynamic performance of the loading system effectively and enables the rapidity and tracking accuracy.Finally, the merits and flaws of the different control laws in this system are analyzed. It can provide some new information in electric loading system's further investigation.