Anti-interference backtracking parameter identification alignment approach for strapdown inertial navigation system

Since the parameter identification alignment approach of strapdown inertial navigation system has such problems as the convergent time is long and the azimuth error is affected by the initial value of recursive calculation, an identification alignment algorithm for backtracking parameters is proposed by the consistency of the formulae, in which the positive and negative direction sequences are obtained by storing and processing the alignment data of gyros and accelerometers. Based on the anti-interference coarse alignment in inertial reference frame, the negative and positive direction identification alignment is used repeatedly in the fine alignment algorithm of backtracking parameter identification alignment. Experiment results confirm that, by the new alignment algorithm, the azimuth error can be reduced by 75% without increasing alignment time.