Control System Design And Implementation For Two-dimensional Airborne Position Stabilized Platform

Research on airborne stabilized platforms has developed rapidly in recent years at home and abroad, mainly used in the front / lower / side object detection systems,missiles and precision-guided weapons, kinetic systems on aircraft and ships and so on.The main function of the stabilization and tracking platform is to track the target accurately and eliminate the influence of the disturbance from the carrier. When the mechanical system and hardware circuit of the platform is determined, the merits of the servo control system directly determines the performance stabilized platform, so the design and implementation of stabilization and tracking control system becomes core and key technology of airborne stabilized platform. In this paper, the study of the stability mechanism and platform control system model is analyzed, the control system based on disturbance observer is designed, and the control system is implemented on embedded hardware system.This thesis focus on the stabilization and tracking servo control system of the airborne antenna stabilization platform, this thesis has mainly completed the following work:1 The structure and working principle of the two-dimensional airborne position stabilized platform, The reference frames of the carrier aircraft and reference rotating frames are established, the movement rule of pitch and azimuth axis two frames is derived, the principle of angular motion isolation is analyzed, and the compensation angle of rotation rate is given. According to the coordinate system transformation among the ground, the carrier aircraft and the antennas, the reference angle is deduced when space target position changes. The model for each axis control system is established, the factors affecting the accuracy and stability of the platform are analyzed,the performance requirements of antenna stabilization platform are discussed.2 Due to the importance of the speed and stability servo loop, so the input-output relationship of the rate stabilization loop is analyzed, the carrier aircraft disturbances and torque disturbances are the important factors that affect the accuracy of platform stability. The function of the velocity loop and position loop is described from the whole platform. In order to suppress the influence of external interference on the stability of precision, the velocity stabilization loop control method based on disturbance observer is proposed. The principle of the disturbance observer is analyzed, and the design of low-pass filter is discussed. The simulation experiment results show that the disturbanceobserver can effectively suppress the influence of disturbances such as friction torque and carrier aircraft disturbances. Since the tracking performance of the PID controller is limited by time and object recognition accuracy issue, the feedforward control is introduced to the PID controller, simulation analysis proves that the method can effectively improve the tracking accuracy.3 The hardware circuitry based on SX95 T is designed, how to acquire the gyro and encoder data is discussed. The proposed algorithm is implemented on the FPGA.