Self-calibration of odometer's scale factor in vehicle navigation system

In this paper, a calibration scheme for odometer's scale factor based on zero velocity update (ZUPT) algorithm for strapdown inertial navigation system (SINS) is proposed. The main factors affecting navigation accuracy in short time after initial alignment of SINS are analyzed. The residual horizontal misalignment angles and upside accelerometer bias of SINS are estimated with ZUPT, and the corrected position information of SINS is used for the calibration of odometer's scale factor. The results of real calibration show that with the scheme, the high calibration accuracy of odometer's scale factor can be achieved with the constant speed driving of vehicle. The longitudinal measurement accuracy of calibrated odometer used for dead reckoning can reach 0.02% when tire inflation temperature is unchanged.