Simulation and Experimental Validation on Touchdown Dynamics of Lunar and Planetary Lander with Translation-Rotation Motion Converting Mechanism

摘要

Landing systems which are adaptable to different kinds of terrain conditions are required to achieve touchdown on rough and inclined terrains. Classical passive landing gears are prone to tip-over when landing on highly uneven and inclined areas. To prevent the lander from overturning, it is necessary to make landing gear adaptable to wide variety of terrain condition. In order to achieve a robust landing on incline, we propose a new mechanism. In general, spacecraft tip over from the torque that is generated by the difference between the forces acting on each leg. However, it is difficult to synchronize the forces acting on all the landing legs. Here, we focus on the difference between the forces acting on each leg. In the case of touchdown on an incline, the forces acting on the upper leg is larger than on any other leg. Therefore, if we can convert this force to torque that opposes the direction of rotating of the spacecraft, it becomes possible to prevent the spacecraft from tipping over. We propose a translation-rotation motion conversion mechanism to enact the above methodology. The effectiveness is validated by simulation and experiment.