Fault-tolerant gait generation for locked joint failures

This paper addresses the issue of tolerating a locked joint failure in gait planning for hexapod robots which have symmetric structures and legs in the form of an articulated arm with three revolute joints. A locked joint failure is one for which a joint cannot move and is locked in place. If a failed joint is locked, the workspace of the resulting leg is constrained, but hexapod walking machines have the ability to continue static walking. A strategy of fault tolerant tripod gait is proposed. In particular, a periodic gait is proposed as a special form of the proposed algorithm and its existence and efficiency are analytically proven. A case study on applying the proposed scheme to the standard tripod gait verifies its applicability and capability.