Design And Implementation For Variable Universe Fuzzy Control Strategy Of Electric Rudder Servo System

Rudder servo system in missile is an important component in the missile flight control system. The traditional analog rudder controller restricts the application of the state of the art control strategy. This limitation leads to the complicated structure and has a negative influence on the overall performance of the rudder servo system as well. The control performance of the brushless DC motor, which serves as the execution mechanism in the rudder system, has a crucial impact on the rudder system response. Based on this situation, the author proposed a digital variable universe fuzzy controller so as to improve the controlling quality of the rudder system.The author firstly analyzed the composition and the working characteristics of the whole rudder servo system. According to the feature of the rudder system, the author proposed a hardware based rudder controller using DSP and FPGA as the central control unit. The objective is to appropriately allocate the system resources when realizing the control algorithm, thus enhance the flexibility, speed and the reliability of the entire control system.In respect of the controlling strategy, the author improved the traditional PID algorithm based on the location-current loop control structure. In the loop of location, a variable universe fuzzy PID control strategy is proposed based on the elastic factor so that two problems are well solved: 1. The balance between the speed and the stability of the regular PID control strategy, 2. The balance between control rules and the control accuracy due to the deterministic universe control strategy deviation and the large range of the deviation.The author analyzed the system stability and the dynamic performance of the single rudder servo system. Besides, the author designed the system model with basis of Matlab and Simulink, and compared the characteristics of the system response and the control performance of the three control strategies. In addition, the proposed controller is applied in practical rudder servo system and the system response under the circumstances of both unloaded and loaded is measured and analyzed. The results show that the position tracking can be preferably attained by applying the proposed strategy. The reliability, real time property and the scalability of the system are prominently enhanced.