Improving the Navigability of a Hexapod Robot Using a Fault-Tolerant Adaptive Gait

Abstract

This paper encompasses a study on the development of a walking gait for fault tolerant locomotion in unstructured environments. The fault tolerant gait for adaptive locomotion fulfills stability conditions in opposition to a fault (locked joints or sensor failure) event preventing a robot to realize stable locomotion over uneven terrains. To accomplish this feat, a fault tolerant gait based on force-position control is proposed in this paper for a hexapod robot to enable stable walking with a joint failure. Furthermore, we extend our proposed fault detection and diagnosis (FDD) method to deal with the critical failure of the angular rate sensors responsible for the attitude control of the robot over uneven terrains. A performance analysis of straight-line walking is carried out which shows that the proposed FDD-based gait is capable of generating an adaptive walking pattern during joint or sensor failures. The performance of the proposed control is established using dynamic simulations and real-world experiments on a prototype hexapod robot.

Object carrying of hexapod robots with integrated mechanism of leg and arm

“…Actually, we can use the other five legs to implement walking while one leg remains leaving ground with gripping objects. That has been demonstrated by researchers who do research on fault tolerant gaits [25][26][27]. We also designed a gait to implement this method to carry objects.…”

Hexagonal hexapod robot foot-modeled dynamics simulation analysis

“…Feng et al [8] study the robot leg and foot end of the analysis of the structure, but they do not study the analysis of the foot terminal friction during walk. Asif [9] et al the analysis of the foot terminal friction during walk, but they do not give the exact mechanics model.…”

Gait and trajectory rolling planning and control of hexapod robots for disaster rescue applications

“…Asif et al [20] proposed a method that is to increase the number of supporting legs according to the roughness of terrain in order to increase stability. Other researchers [21][22][23][24] focused on the analysis of fault tolerant gait as one or more legs are prevented from supporting and swing. Grzelczyk et al [25][26][27] discussed the application of central pattern generators (CPGs) on hexapod robots to get stable and low energy consumption gaits.…”