Research On Kalman Filter For Strapdown Attitude & Heading Measurement System

Under the background of RLG Strapdown Attitude&Heading Measurement System(SAHMS) software design, the method of initial alignment using Kalman filter is extensively studied in this dissertation. In particular, this dissertation have a primary study in the field that how to apply Kalman filter method to the alignment of SAHMS in stationary state and alignment of marine SAHMS in moorage. The main work is as follows:Firstly, a kind of methods of initial alignment using Kalman filter is set up, in which velocity error is used as exterior value of observation. The general error model of SAHMS is studied, Kalman filter method is applied to make the optimization estimation of attitude errors and build the "digital platform".Secondly, the approach of alignment of SAHMS in stationary state is put forward. Both simulation and experiment validate the efficiency of the algorithm.Finally, based on the analysis of lever arm correction, the approach of alignment of marine SAHMS in moorage is proposed. Lever arm error is corrected through calculating the length of lever arm, which is equivalent to move the SAHMS to the swinging center, then Kalman filter method can be applied for self-alignment using the information that the velocity of swinging center approximate to zero. Initial alignment of SAHMS located in swinging center(no need of lever arm correction) is studied by simulation and experiment. Only simulation is done for alignment of SAHMS which is not located in swinging center (lever arm correction must be done). Simulation and experiment illustrate the efficiency of alignment algorithm.