惯性平台自标定中惯性仪表安装误差可观测性分析

Observability analysis for misalignments of inertial sensors in inertial platform self-calibration

针对惯性平台自标定中惯性仪表安装误差可观测性问题,深入研究了系统模型与平台坐标系对惯性仪表安装误差可观测性的影响。根据不同系统动力学模型和观测量构建四种系统模型。从可观测性定义出发,分析与判断惯性仪表安装误差在不同系统模型和不同平台坐标系下的可观测性。理论分析和仿真结果均表明惯性仪表安装误差在以下两种情况完全可观:观测量为平台框架角和加速度计输出,系统动力学模型为框架角模型,平台坐标系以平台六面体为基准定义;观测量为加速度输出,系统动力学模型为姿态角或失准角模型,平台坐标系以加速度计敏感轴为基准定义。

For the observability of inertial sensor misalignments in inertial platform self-calibration problem, the effects of the system model and platform coordinate frame on observability were analyzed. Based on different system dynamic models and measurement vectors, four system models were built. The observability of inertial sensors misalignments in different models with different definitions of platform coordinate frame was investigated. The theory conclusions and simulation results show that the system is observable only in two conditions : the system measurement models are bu ilt up with platform angles and accelerometer triad outputs, the system dynamic model is built up with platform angles and the platform coordinate frame should be defined with the benchmark hexahedron of platform ; the system measurement models are built up only with accelerometers triad outputs, the system dynamic models are built up with platform attitude or misalignment models and the platform coordinate frame should be defined with the accelerometer sensor axes.