一种高可靠捷联惯性测量单元布局

冗余传感器惯性测量单元通过传感器余度配置能够有效提高惯导系统的可靠性,同时对运动的重复测量为降低传感器测量误差和提高导航性能提供了必要条件。一种新型9传感器惯性测量单元,在实现9传感器最佳导航性能布局的同时,保障了每个方向的平动或者转动均可同时由5个传感器进行测量,使其可靠性等同于6套并行工作的单轴独立惯导系统。利用GLT(Generalized LikelihoodTest)方法和Monte Carlo模拟完成了该惯性测量单元故障检测、隔离性能研究。分析结果表明,该惯性测量单元的平均无故障时间为正十二面体6传感器惯性测量单元的1.4倍,为三轴正交配置惯性测量单元的3.8倍,传感器测量随机误差造成的影响分别降低13%和40%。因此,该布局特别适合于对长使用寿命、高安全性、高可用性有严格要求的应用领域。

A strapdown IMU configuration with high reliability

With multi sensors configuration,a redundant sensor IMU(Inertial Measurement Unit) can increase the reliability of INS(Inertial Navigation System),and its repetitive measurements on the same movement provide the necessary condition to lower the sensor measurement error and improve navigation accuracy of INS.In this paper,a novel 9-sensor IMU configuration is presented,which can guarantee every single translational and rotational movement be simultaneously measured by 5 sensors,and its IMU’s reliability is equal to that of 6 individual IRS working in parallel.GLT(Generalized Likelihood Test) and Monte Carlo simulation is made to obtain the capability of fault detection and isolation.The simulation results show that MTBF of the presented IMU is 1.4 times more than that of 6-sensor dodecahedron IMU and 3.8 times more than that of 3-sensor orthogonal IMU,and the influences caused by sensors’ measurement random error are reduced by 13% and 40% respectively compared with those of 6-sensor dodecahedron IMU and 3-sensor orthogonal IMU.As a result,it can be used in such applications where there are critical requirement on long-life,high safety,maintainability and availability.