Semi-physical simulation system of autonomous optical navigation for Mars-approaching phase

Strategy of autonomous optical navigation for Mars-approaching phase and its semi-physical simulation method were studied. First, the dynamics model was set up based on the reference orbit preliminarily designed in a Mars exploration mission. Second, the observation model and an EKF filtering algorithm were developed. Then, a semi-physical simulation system was founded including five modules: an orbit producer, a Mars simulator, a camera system, an autonomous optical navigation module and a display module. The position and velocity were solved using simulated observation data, and the results of several deferent conditions were listed. Influence of initial orbit error and camera parameters were analyzed, which validated the practicability of the simulation system.