调制型捷联惯导系统可观测性分析及在线标定技术研究

Observability analysis and research on the on-line calibration technique for modulated strapdown inertial navigation system

针对调制型捷联惯导系统(modulated strapdown inertial navigation system,MSINS),提出了惯性组件(inertial navigation unit,IMU)的在线标定路径设计原则。首先根据IMU输出误差模型建立了系统误差模型,而后利用该模型,分析了载体无加速运动且转台静止情况下的可观测性,分析结果表明该状态下有一半状态量不可观测;针对该现象,对系统模型进行了能观测性分解,通过分解结果观察无法估计的状态量,并且得到了分解后系统的可观测性矩阵,在此基础上,推导了满足该矩阵满秩的IMU运动原则,由此归纳出IMU在线标定路径设计原则;最后,利用仿真试验验证了该方法的正确性,半实物仿真试验验证了该方法的工程适用性。

According to the basic principle of the modulated strapdown inertial navigation system （MSINS）, the design principle of on-line calibration trajectory is improved.Firstly,the system error model is established based on the inertial navigation unit （IMU）output error model.And then,the system observability is analyzed in the case of no accelerated motion and no turntable rotating.The results show that half of the state amounts are unobserved.In order to solve the problem,the unobserved state amounts are selected by observability de-composition.And the IMU movement principle,which makes the observability decomposition matrix full rank, is derived.The principle of the on-line calibration trajectory is improved on the basis.Finally,its effectiveness is demonstrated by simulations and turntable experiments.The results show that this design principle can fur-ther compensate for the IMU errors and improve the MSINS accuracy.