Controller Design And Application Research Of The High Frequency Motion Simulation System

According to development needs of the modern military weapons, the demand ofthe missile’s speed and attack precision is higher and higher, the structure design of themissile’s shape is more and more slender, at this time the elasticity vibration of theprojectile jitter can’t be ignored, so the requirement for motion simulation system isstricter and stricter, in this paper a new kind of motion simulation system that can notonly track large angle maneuvering but also track the small value of high frequencydithering signal is proposed.First, make sure the structure of the high frequency motion simulation system, itconsists of the traditional three-axis turntable and a Stewart platform fixed on the innerring of it, the system uses the compound axis control strategy, the three axis turntable isused for tracking large Angle attitude changes, and the Stewart platform is used fortracking missile’s high frequency jitter, the output of two systems added together isserved as the output of the high frequency motion simulation system.Secondly, the kinematics reverse solution, position positive solutions of Stewartplatform and the dynamics model was analyzed, and according to the special way towork of Stewart platform, we will design a kind of instruction resolving method suitablefor the Stewart platform.Then, according to the structure, work mode and application requirements of thehigh frequency motion simulation system, the disturbance which is caused by thethree-axis turntable and Stewart platform working together is analyzed, also, theinterference factors introduced by complex structure of Stewart platform is analyzed,and then, based on these influence factors the disturbance observer, a notch filter andinterference force feedforward compensation scheme is put forward, these is conduciveto the high frequency motion simulation system to realize high precision tracking.In the end, according to the large changing of parameter, complex interference, andthe high tracking accuracy of Stewart platform’s characteristics, the sliding modecontroller which has good quickness, strong robustness and high tracking accuracycharacteristics is designed, and the reaching law, the saturation function and disturbanceobserver are designed to weaken the high-frequency vibration introduced by slidingmode control. The stability and tracking precision performance characteristics of slidingmode control is analyzed from the perspective of theory, and the relation of the slidingmode control and feedforward control designed on frequency domain is analyzed, itproves that the sliding mode control can effectively improve the system trackingprecision and frequency band width. According to the linear motor’s parameters of Stewart platform a sliding mode controller is designed, the simulation results show thatthe sliding mode control is advantageous to the system to achieve high precisiontracking requirements.