機載雷達偵照系統之視線控制

Abstract

雷達是利用反射波來偵測遠方目標物並獲得其方位的一種裝置。機載雷達由於飛機載具本身的運動、受到大氣亂流的干擾或飛機本身結構的震動等，造成雷達掃瞄軌跡的偏移，致使雷達搜索性能降低。為了改善此一現象，雷達必須針對飛機運動的變化修正雷達掃瞄路徑軌跡，以消除其運動誤差。本論文主旨在於實現機載雷達天線穩定系統，於雷達天線基座上加裝一個可作兩軸旋轉之環架式機構，利用此機構補償飛機姿態的變化，使天線視線能夠固定對著某一方位。在此系統中，藉由視線控制的演算法產生穩定天線所需的命令，並利用陀螺儀及角度感測器作為回授訊號之感測器，進而設計控制器以降低追蹤誤差。

Radar is a device of using electromagnetic waves to detect the presence of the target and extract its location and relative velocity. The airborne radar deviates from its predicted trajectory by pilot-induced maneuvers, atmospheric gusts disturbance and structural vibrations, and will decrease the detection efficiency of radar. In order to improve the problem, we have to compensate the motion uncertainty of aircraft and correct the motion deviation of radar. The purpose of the thesis is to implement the antenna stabilization system of airborne radar. By setting up a two-axis gimbal mechanism on the antenna pedestal, we can compensate the changing attitudes of aircraft and stabilize the antenna line-of-sight in a designated earth-fixed location. Algorithm used for line-of-sight control generates commands to stabilize and point antenna. The gyroscope and encoders are taken as the sensors of feedback signals in this system. PID controller is developed to minimize tracking error and improve system performance.