A New Online-Identification Algorithm for Odometer´s Scale Factor

A identification in a nonlinear stochastic system - strapdown inertial navigation system is addressed. A new online-identification algorithm of odometer´s scale factor is proposed. From zero velocity update (ZUPT), the velocity errors in inertial navigation system propagate in the Schuler loops, and based the slow-varying property of velocity errors, the algorithm identifies the odometer´s scale factor using the changes of velocity during a short time. A tracking differentiator and a fadeout memory LMS algorithm is adopted in the identification to make the algorithm more practicable. The algorithm can track the odometer´s scale factor varying with time, and therefore be suitable for navigation case in which a vehicle runs a long time and roads vary a lot. Simulation indicates that this new algorithm can identify the odometer´s scale factor fast with small errors, so as to improve the accuracy of navigation.