A Stepwise Simple Self-Calibration Method for Low-Cost MEMSIMU.

The low-cost MEMS-IMU is affected by the biases, the scale factors and the misalignment errors, which will cause the measurement errors of the IMU, and then cause the large system errors. Traditional calibration method based on laboratory turntable is complicated and expensive, so it has become a trend to study the self-calibration method without relying on special equipment such as turntable. In traditional self-calibration methods, 12 full error parameters of accelerometer are usually estimated at one time with optimization estimation algorithm, which will cause the problem of high complexity, long estimation time and low accuracy. In this paper, we proposed a stepwise self-calibration method by estimating the biases and other 9 error parameters step by step, under which the estimation accuracy can be improved and the algorithm complexity can also be reduced. In addition, considering the characteristics of gyroscope biases successive start fluctuation, online calibration strategy of the gyroscope biases is also adopted. Turntable experiment shows that the 24 error parameters of accelerometer and gyroscope can be calibrated quickly in 8 minutes by the method proposed in this paper. The estimation efficiency is 10~20 times faster than that of one-time estimation method. The calibration errors of the accelerometer are within 0.2 m/s, the calibration errors of the gyroscope are within 0.5 °/s, and the calibration accuracy is more than 95%.