一种惯性测量单元非正交安装的单轴转位方法

摘要

针对单轴旋转式捷联惯导系统中旋转轴方向惯性器件误差导致系统误差积累的问题,提出一种惯性测量单元非正交安装的单轴转位方法,该方法不但可消除旋转轴垂直方向惯性器件误差对导航精度的影响,而且可减小旋转轴方向惯性器件误差引起的导航误差.基于单轴旋转调制原理,推导了非正交安装方法和正交安装方法的陀螺常值漂移和加速度计零偏在单轴旋转下引起的姿态误差,并对其进行分析,结果表明,在陀螺仪和加速度计常值漂移及零偏相同的情况下,非正交安装方法与正交安装方法相比,安装斜角为10°时72h的定位误差降低约50％.%In single-axis strapdown inertial navigation system,the inertial measurement unit (IMU) error along the rotating axis is accumulated with time.To solve this problem,a single-axis rotation modulation method for the non-orthogonal installation of IMU is proposed.By applying the proposed installation method,not only the effect of navigation accuracy due to IMU errors in the orthogonal direction of the rotating axis can be eliminated,but also the navigation error caused by IMU errors in the rotating axis direction can be reduced.Based on the theory of single-axis rotation modulation,the pose errors caused by the constant drift of gyroscope and the zero bias of accelerometer are deduced and analyzed under single-axis rotation by two different methods,namely,the orthogonal rotation and the non-orthogonal rotation.Simulation results show,compared with the orthogonal installation,the 72 h navigation accuracy in case the installation angle is 10° can be improved by 50％ under the same conditions of constant drift and zero bias.