冗余惯组故障检测与隔离的广义似然比解耦矩阵构造新方法

冗余惯组可提高运载火箭制导系统的可靠性,惯性器件发生故障会污染导航信息,需要进行在线故障检测和隔离。面对安装矩阵一定的成套冗余捷联惯组,使用Potter算法构造解耦矩阵的广义似然比故障检测方法,无法检测并隔离特定轴故障,提出选择正交投影矩阵的极大无关组来构造解耦矩阵,采用全数字仿真对改进方法进行验证。结果表明,新方法克服了成套惯组同轴共基座安装时某个轴向无法故障检测的问题,且故障检测性能没有降低。该方法为运载火箭制导系统在线故障检测技术提供了一种新思路。

New decoupling matrix method for generalized likelihood fault detection and isolation of redundant IMU

Integrating multiple inertial sensors by using appropriate redundant configurations can greatly enhance the guidance system's reliability.Failure of the inertial device will pollute the navigation information, which needs to be detected and isolated.The existing generalized likelihood test (GLT) method with Potter decoupling matrix constructed cannot detect and isolate the faults of several strapdown inertial measurement units along a specific axial direction, because Potter method does not satisfy linear correlation conditions.This paper proposes construction of the decoupling matrix by selecting the maximal linearly independent systems of the orthogonal projection array and then orthogonalizing and unitizing the maximal uncorrelated set.Numerical simulation performs of several configurations of redundant strapdown inertial measurement unit to verify the fault detection and isolation effects of the improved generalized likelihood test method.The simulation results show that the improved generalized likelihood test method can detect and isolate the faults of several configurations of redundant strapdown inertial measurement unit.This method provides a new idea for the on-line fault monitoring technology of the launch vehicle guidance system.