基于EKF的导弹制导系统故障检测

EKF-Based Fault Detection for Guided Missiles Flight Control System

制导系统是影响地空导弹制导精度和杀伤概率的关键环节,系统复杂,执行器和传感器故障多发,严重影响整个武器系统的可靠性,为了对制导系统故障诊断的准确性进行优化,在考虑外界扰动的条件下,针对制导系统中非线性闭环系统的执行器与传感器故障,提出了一种采用扩展卡尔曼滤波的故障检测方法和x^2检验的故障评价方法。首先,对带有扰动项的制导系统非线性故障模型进行欧拉离散化,然后对离散化后的故障模型设计扩展卡尔曼滤波器的残差产生器,并在忽略泰勒展开高次项的情况下,利用x2检验对残差进行评价,实现了对导弹制导系统的故障准确检测。最后,对升降舵故障进行了仿真,结果证明了改进方法的有效性。

The guided missile flight control system is essential for guidance accuracy and kill probability. It is complicated and fragile. Since actuator faults and sensor faults could seriously affect the security and reliability of the system,fault detection for missiles flight control system is of great significance. This paper deals with the problem of fault detection for the closed-loop nonlinear model of the guided missiles flight control system in the presence of disturbance. First,the Eulerian-discrete fault model of flight control system in the presence of disturbance is set up,and then the residual generation is designed based on the extended Kalman filter（ EKF） for the Eulerian-discrete fault model. After that,the Chi-square test is selected for the residual evaluation and the fault detention task for guided missile closed-loop system is accomplished. Finally,simulation results are provided to illustrate the effectiveness of the approach proposed in the case of elevator fault separately.