冗余捷联惯组故障诊断等价向量的补偿

Parity Vector Compensation for FDI in Redundant-IMUs

摘要:

运载火箭作机动飞行时,陀螺和加速度计输出中引入的与机动状态相关的动态误差项会严重影响冗余捷联惯组故障诊断的效果,增大误警率；研究验证了利用卡尔曼滤波估计动态误差以补偿等价向量的方法,滤波补偿能够减弱由于运载火箭机动引起的动态误差项,利用补偿后的等价向量成功检测到未补偿时难以检测的故障；同时也发现了陀螺的补偿效果不如加速度计补偿效果好的现象；深入研究后发现,试验陀螺的随机误差偏大,掩盖了动态误差；得到了当传感器的随机误差项是动态误差项的5倍以上时可不进行误差补偿的有用结论。

Abstract:

The output of IMU contains dynamic errors, related to the maneuver state of the rocket, which influence negatively the fault diagnosis. The method is studied, that using Kalman filter to estimate the linear combinations of the dynamic errors to compensate the parity vector, which is used to make fault diagnosis decision. Simulations show that the method is successful. But the compensation result of accelerometers is better than the gyros’. The problem is solved by intensive research. The strong random noise of the gyros covers the dynamic errors, which makes the compensation results worse. Finally, a conclusion drawn that there is no need to compensate the parity vector, when random noise is 5 times more than dynamic errors.