An Improved Attitude Determination-Based Alignment for Odometer-Aided In-Motion SINS

In-motion coarse alignment is an important part for the odometer (OD)-aided strapdown inertial navigation system (SINS). In this paper, an improved attitude determination (AD) based alignment algorithm for OD aided in-motion SINS is proposed. Firstly, improved vector observations are proposed to reduce the model errors of the vector observations in the conventional AD-based alignment. Secondly, in order to address the side effects on the coarse alignment caused by faulty odometer measurement information, a linear state-space model is proposed, and then an OD measurement information detection and isolation procedure is established. The results of simulation experiments show that the improved alignment algorithm can effectively suppress the side effects due to the faulty OD measurement information, and the improved alignment algorithm has shorter convergence time and higher accuracy than the conventional AD-based alignment method.