SpinyHand: Contact Load Sharing for a Human-Scale Climbing Robot Shiquan Wang∗ † Hannah S. Stuart Hao Jiang∗ Assistant Professor Tae Myung Huh Dept. of Mechanical Engineering Danning Sun University of California Wilson Ruotolo 2521 Hearst Avenue Matthew Miller Berkeley, California, 94709 USA Will R. T. Roderick
[email protected] Graduate Research Assistant Dept. of Mechanical Engineering Stanford University 424 Panama Mall, Bldg 560 Stanford, California, 94305 USA Mark R. Cutkosky Professor Dept. of Mechanical Engineering Stanford University 416 Escondido Mall, Bldg 550 Stanford, California, 94305 USA
[email protected] recent years, a number of climbing robots have used claws We present a hand specialized for climbing unstructured or arrays of miniature spines to climb steep and even vertical rocky surfaces. Articulated fingers achieve grasps commonly surfaces like concrete and stucco walls [1–12]. Most of these used by human climbers. The gripping surfaces are equipped platforms are limited to relatively uniform surfaces. A large with dense arrays of spines that engage with asperities on robot, with long legs, can traverse complex surfaces by step- hard rough materials. A load-sharing transmission system ping over obstacles and bridging gaps. However, it becomes divides the shear contact force among spine tiles on each increasingly challenging to obtain sufficient traction with in- phalanx to prevent premature spine slippage or grasp failure. creasing robot size, denoted by L, because mass grows as L3 Taking advantage of the hand’s kinematic and load-sharing while foot contact area grows as L2. Failure can be catas- properties, the wrench space of achievable forces and mo- trophic for a large climbing robot when it falls from heights ments can be computed rapidly.