一种弹载单轴旋转式捷联惯导系统在架标定方法

An on-launcher Calibration Method for Missile-borne Single-axis Rotation Strapdown Inertial Navigation System

捷联惯导系统经长时间存放,其模型参数相对实验室标定值会产生较大变化,导致系统无法满足导航精度要求。为适应弹载捷联惯导系统长期稳定使用的需求,降低定期标定的保障成本,提出了一种弹载单轴旋转式捷联惯导系统在架标定方法。该方法通过分析不同机动状态与惯导待标定参数的激励关系设计标定路径,采用状态变换扩展卡尔曼滤波(STEKF)估计各状态量,并在计算速度观测量时考虑了外杆臂误差的影响。仿真结果表明,该方案可在10 min内实现陀螺仪和加速度计零偏以及刻度因数的标定,且在有振动噪声干扰的情况下,STEKF模型的估计精度优于卡尔曼滤波(KF)模型。STEKF模型估计得到的状态量相对误差均小于15%,加速度计各项参数相对误差均小于8%。通过外场试验验证,该标定方法可较准确地标定出惯导零偏和刻度因数。

Due to prolonged storage,the model parameters of the strapdown inertial navigation system undergo changes compared to the laboratory calibration results,resulting in the system being unable to meet the navigation accuracy requirements.In order to meet the demand for the parameter stability of missile-borne strapdown inertial navigation systems and reduce the guarantee cost of regular calibration,an on-launcher calibration method for missile-borne single-axis rotation strapdown inertial navigation system is proposed.This method designs a calibration path by analyzing the excitation relationship between different maneuvering states and the parameters of inertial navigation to be calibrated.The state transformation extended Kalman filter(STEKF)is used to estimate state variables,and the influence of outer lever arm error is considered when calculating velocity observations.The simulation results show that this scheme can calibrate the bias and the scale factor error of gyroscope and accelerometer within 10 min,the estimation accuracy of the STEKF model is better than that of the KF model in the presence of vibration noise interference.The relative errors of the state variables estimated by the STEKF model are all less than 15%,and the relative error of each parameter for the accelerometer is less than 8%.Field experiment verifies that this method can accurately calibrate the bias and the scale factor error of the strapdown inertial navigation system.