Compliant leg designs for attenuating impact of airdrop landing of quadruped robots

摘要

Most airdropped cargos use a combination of one or more parachutes and an impact attenuation system to land safely. The latter adds cost, weight and complexity. However, by using their legs for impact attenuation, quadruped robots may not need such a system. In this study, three types of leg configurations were considered for impact attenuation. Using simple lumped element models for simulation and analysis, it was decided that a compliant three-segmented leg configuration with a linear spring on each leg would yield both good walking and impact attenuation performance. Via series of tests with a small scale 20 cm-tall robot, the simulation model was validated, and it was shown that the test robot experienced 7.9 G-acceleration when dropped from height of 37.85 cm. In contrast, when equipped with rigid legs the robot experienced a 14.7 G-acceleration when dropped at 10% of the same height. Our leg design method can be used for impact attenuation of airdrop landings for larger robots.