Soft-landing control for a six-legged mobile repetitive lander

The primary mode of extraterrestrial exploration is a robotic system comprising a lander and a rover. However, the lander is immovable, and the rover has a restrictive detection area because of the difficulties of reaching complex terrains, such as those with deep craters. In this study, a six-legged mobile repetitive lander with landing and walking functions is designed to solve these problems. First, a six-legged mobile repetitive lander and its structure are introduced. Then, a soft-landing method based on compliance control and optimal force control is addressed to control the landing process. Finally, the experiments are conducted to validate the soft-landing method and its performances. Results show that the soft-landing method for the six-legged mobile repetitive lander can successfully control the joint torques and solve the soft-landing problem on complex terrains, such as those with steps and slopes.