Vision-aided inertial navigation for pin-point landing on Mars

A vision-aided inertial navigation algorithm is proposed within an EKF framework for spacecraft precision entry, descent and landing on Mars. By combing vision information with inertial measurement, it can not only avoid error accumulation of the IMU dead reckoning, but also obtain accurate and robust sate estimation in a real-time and high rate fashion. A special procedure based on state augmentation is developed to account for the delays of image processing. The problem associated with the sparse measurement information during the descent terminal phase is addressed as well by processing the previously unknown features. Simulation results demonstrate that the proposed integrated navigation system can provide high-precision motion information required by the upcoming planetary exploration missions.