斜置惯性测量单元的一体化标定技术

IMU integrated calibrating technique with skewed sensor axes

针对陀螺和加速度计均倾斜安装的低精度惯性测量单元,将三个 MEMS 加速度计组件和三个光纤陀螺组件分别考虑为一个整体,提出了一体化标定技术,将传统的零位、比例因子、安装误差等参数等效考虑为一个转换矩阵。根据实验得到的低精度斜置惯性测量单元的温度特性和非线性的经验公式,提出了补偿温度特性和非线性的一体化标定模型。利用速率转台和大理石平板在不同温度下进行测试,采用多元线性回归,得到了实用的角速度模型与加速度模型。实时补偿效果表明,当温度从 0℃到 24℃变化时,在±60(°)/s 转速内角速度误差小于 0.02 (°)/s,加速度误差小于 0.003g。

The low-cost inertial measurement unit （IMU） includes three skewed fiber-optics gyroscopes （FOG） and three skewed MEMS accelerometers. Considering three FOGs and three accelerometers respectively as a whole, an integrated calibrating technique was advanced in which an equivalent transfer matrix replaced the traditional bias, the scale factor and the misalignment errors. Based on the experimental formulas for the low-cost skewed IMU＇s temperature dependency and non-linearity, a new integrated calibrating model was developed which could compensate its temperature dependency and non-linearity. After testing in different temperature with rate table and marble plat, two applied models of angular velocity and acceleration were got via multiple linear regressions. The real-time compensation shows that the skewed IMU＇s angular velocity error is less than 0.02 （°）/s with operating range of ＋60 （°）/s, and its acceleration error is less than 0.003g for the temperature range（0℃to24℃）.