一种常规机动下机载SINS/GPS组合导航系统的可观测性分析

为保证机载捷联惯组的导航精度能够达到要求，需要对惯组定期进行返厂标定，成本高、周期长，也影响载机的使用效率，故而机载惯组在线标校技术的研究一直在不断进行中。对大中型运输机的机载惯组而言，由于其机体较大、机动能力较差，很难完成诸如S机动等复杂的机动动作，故而需要对其常规飞行机动状态下机载SINS/GPS组合导航系统的可观测性进行分析。利用GPS提供的速度和位置信息作为外部观测量来设计Kalman滤波器，采用基于分段线性定常系统(PWCS)的奇异值分解法(SVD)，对飞机静止、起降、匀速飞行、匀加减速飞行、转弯等一系列常规机动条件下系统的可观测性和可观测度进行研究。通过Matlab仿真和转台实验，验证了组合导航系统可观测性分析结论的有效性，可为机载惯组的在线标校提供一定参考。

Research on Observability of an Airborne SINS/GPS Integrated Navigation System in Conventional Maneuvering

In order to ensure the navigation accuracy of the airborne strapdown IMU can meet the requirements, the airborne strapdown IMU needs to be regularly returned to the factory for calibration which has high cost and long cycle, and also affects the use efficiency of the aircraft carrier. Therefore, the research on the online calibration technology of the airborne strapdown IMU has been continuously carried out. As for the airborne strapdown IMU of large and medium-sized transport aircraft, it is difficult to complete complex maneuvers such as S-maneuver due to its large airframe and poor maneuvering ability. Therefore, it is necessary to analyze the observability of the airborne SINS/GPS integrated navigation system in the conventional flight maneuvering state. The velocity and position information provided by GPS is used as external observation to design Kalman filter. The singular value decomposition(SVD) method based on piece-wise constant system(PWCS) is used to study the observability and observability degree of the system under a series of conventional maneuvering conditions, such as stationary, takeoff and landing, uniform flight, uniform acceleration and deceleration flight, and turning. Through Matlab simulation and experiment on rotary table, the observability analysis conclusion validity of the integrated navigation system is verified, and it can provide some theoretical basis for the online calibration of airborne strapdown IMU.