Research Of Navigation Algorithm In The SINS

The measure axes of gyros and accelerometers are mounted to the vehicle directly in strapdown inertial navigation system (SINS). Because of vehicle's dynamics, angular and linear vibrations of the measure axes would be arised. That result in the noncommutativity during the computation of navigation parameters. The noncommutativities are called by coning error in attitude algorithm, sculling in velocity algorithm and scrolling in position algorithm respectively. This thesis introduced usual frames and the basic theory for SINS. Several strapdown algorithms were designed to reduce the noncommutativity effectively.Study on attitude-updating algorithm. Coning errors were analyzed here. Attitude updating algorithm based on quaternion and rotation vector were studied respectively. After optimizing sample-compensation algorithms and deducing recurrent algorithm, a two-ample iteration algorithm was derived. Simulations were used to analyze the performance of each algorithm.Study on velocity-updating algorithm. Making various kinds of algorithm optimized under the classical sculling environment. That minimizes the excursion rate. The iteration compensation algorithm and recrrent compensation algorithm were deduced. The computational accuracy for every algorithm was evaluated through simulations.Study on Position-updating algorithm. The scrolling error in the position updating calculation is discussed and the scrolling compensation algorithms are optimized under the classical sculling environment.