滾轉飛彈複合控制系統設計

Abstract

本論文主要探討攔截飛彈在定速滾轉的條件下進行尾翼搭配側向推力的複合控制系統設計。複合控制以尾翼為主制動器，輔助致動器則是由環狀排列於彈體的180個微型發動機產生側向推力，藉此改善純尾翼控制的攔截效果。考慮飛彈為定速滾轉時造成俯仰及偏航方向的耦合現象，因此必須同時對兩個方向進行尾翼控制器的設計。由於飛彈定速滾轉，在一般攔截的情況下，體座標兩軸的加速度命令均有明顯週期性訊號的成分。根據飛彈在定速滾轉下的線性模式，設計線性解耦控制器，除了達到暫態響應的要求外，亦因在迴路加入內模式而對弦波式的週期性命令有零誤差的穩態跟蹤效果。微型發動機則是參考愛國者三型飛彈的配置方式，在數量有限且每個發動機為一次性的使用條件下，藉由滾轉的特性選擇適當的點火邏輯演算法，並且搭配順滑模控制來進行側向推力的輔助控制，使得複合控制可以有較快速的響應，滿足在目標有較高的機動性的情況下，依舊能夠達成直接命中的需求。

This thesis investigates a blended controller design method for spinning missile interceptors, which includes two actuators, the tail fins and lateral thrust. The tail fin controller provides tracking of acceleration command in a general engagement situation. The lateral thrust controller is used to enhance tracking performance which may be inadequate with tail fin acting alone. The required lateral thrust is supplied using 180 micro thrusters placed in circular ring, around the front section of the interceptor. In order to make use of the micro thrusters more efficiently, the interceptor controlled to spin at a fixed rate. In general engagement, slow ranging acceleration commands in inertial coordinate induce periodic component in body coordinate. We design a linear decoupling controller by linear dynamics of spinning missile. Besides reaching the demand of transient response, we add the internal model for tracking of sinusoidal periodic command perfectly in steady state. The lateral thrust designed using sliding mode control theory is nonlinear and provides fast and robust system response. A firing logic algorithm which takes into account accuracy and propellant usage is proposed and compared with several algorithms in the literature. Simulation results show that the designed blended controller give satisfactory performance in a hit-to-kill scenario.