Fault tolerance criteria and walking capability analysis of a novel parallel-parallel hexapod break walking robot

Abstract

SUMMARY Fault tolerance is a very important issue for legged robots, especially in some harsh environments. One of the most fragile parts is the actuation system. There are two common faults of robot actuators: (1) the motor is locked and could not move anymore; (2) the motor is uncontrollable and can be treated as a passive joint. In this paper, we first discuss all fault combinations of a single leg of a hexapod walking robot with parallel-parallel mechanism topology. Then, the leg tolerable criterion is brought out, which defines whether a leg is fault tolerant. After that, the fault tolerance of the whole robot is researched, and we found that the robot can walk with one tolerable leg or two opposite tolerable legs. Finally, relative simulation results are given, which show the robot walk with one or two broken legs.