基于IMU标定补偿的列车组合定位优化方法

GNSS/INS组合方式是下一代列控系统定位技术的发展趋势,但由于惯导系统累计误差较大,使得列车处于卫星信号失锁环境下定位性能降低。为解决这个问题,针对微机械惯性测量单元IMU确定性误差的3个主要误差项:非正交误差、零偏误差、刻度因数,建立加速度计和陀螺仪的误差模型,在此基础上详细推导标定原理并提出标定方案。将误差补偿结果应用于京沈高速铁路试验现场并由试验结果分析可知:该方法能有效提高IMU的测量精度,相较于补偿前测量误差降低80%以上;补偿之后的惯导系统在40s时间内的导航速度误差小于1m/s,位置误差在10m之内,满足定位需求,具有实际意义的工程应用价值。

Optimization Method for Integrated Train Positioning Accuracy Based on IMU Calibration Compensation

GNSS/INS integration method is the development trend of positioning technology for next generation train control system.However,the accumulation of excessive errors from the inertial navigation system causes the reduction of the positioning performance of the train in the satellite signal failure environment.In order to solve this problem,this paper focused on the three main error items of IMU’s deterministic error,including non-orthogonal error,zero offset error and scale factor,and established the error models of accelerometer and gyroscope.In addition,the calibration principle was deduced from the above formula and a calibration scheme was proposed.The application of the error compensation results to the test site of the Beijing-Shenyang high speed rail demonstrates that the method can effectively improve the measurement accuracy of the IMU,and reduce the measurement error by more than 80%compared with the measurement error before compensation.After the compensation,the inertial navigation system has a navigation speed error of less than 1 m/s in 40 s,and a position error of less than 10 m,which meets the positioning requirements and has practical engineering application value.