Abstract:

A multi-position calibration method in outer field is presented based on extended observation to improve the accuracy of the vehicle-based strapdown inertial navigation system (SINS) and shorten the calibration time, according to the vehicle-based SINS using characteristics. With the extended information of gyroscope and analysis about observability, a new outer filed calibration method is designed based on the traditional calibration method, then experiments are conducted. The experiment results show that, after introducing the equivalent gyroscope error, the upright gyroscope drift observation increases from 0.0006 to 0.9999, whose rate of convergence is faster with the improved accuracy and speed of initial alignment. The result of the outer field calibration can match the theoretical value, and the error is less than 15%. It has definite value to engineering application.