A precise vision-based navigation method for autonomous soft landing of lunar explorer

During the entry, descent and landing (EDL) phase of the lunar explorer with a high degree of accuracy, the dual quaternion and the unscented Kalman filter (UKF) based vision navigation method is presented, in order to accomplish navigation task. The lunar explorer´s pose estimation method is developed through dual-quaternion calculation. The state equation is derived according to the dynamic model of the lunar explorer during the power descent phase, and the measurement equation is derived by constructing feature points triangle. Because of the nonlinear property of the state function and measurement function, the UKF method is used to estimate the pose of lunar explorer. Simulations demonstrate the validity of the proposed method.