Abstract: Aiming at the characteristics of multi body motion and surface terrain uncertainty during the Mars landing process of Tianwen 1 probe, a collaborative control strategy of coarse hazard avoidance and parachute backshell assembly avoidance, and a fine hazard detection strategy of laser 3D imaging combined with binocular stereo vision are proposed. The hazard detection and avoidance system hardware configuration, flight sequence, hazard detection and avoidance algorithms are also introduced. The effectiveness of the proposed hazard detection and avoidance strategy is demonstrated through the special suspending and hazard avoidance ground experiment. The work of this paper may provide certain reference for the landing process of subsequent Mars sample return missions and manned Mars exploration missions.

Key words: Tianwen 1 probe, Guidance, navigation and control (GNC), Hazard detection and avoidance, Entry, descent and landing (EDL)