A free gait controller designed for a heavy load hexapod robot

Fusheng Zha,Junyi Shi,Penglong Zheng,Wei Guo,Chen Chen

doi:10.1177/1687814019838369

Abstract

As macroscopic rough terrains are time varying and full of local topographic mutations, stable locomotions of legged robots moving through such terrains in a fixed gait form can be hardly obtained. This problem becomes more severe as the size and weight of the robot increase. An ideal pre-planned gait changing method can also be hardly designed due to the same limitations. Aiming to solve the problem, a new kind of free gait controller applied to a large-scale hexapod robot with heavy load is developed. The controller consists of two parts, a free gait planner and a gait regulator. Based on the observed macro terrain changes, the free gait planner adopts the macro terrain recognition method and the status searching method for selecting the best leg support status automatically. The gait regulator is adopted for the correction of the selected status to cope with local topographic mutations. Detailed simulation experiments are presented to demonstrate that, with the designed controller, the adopted hexapod robot can change moving gaits automatically in terms of the terrain conditions and obtain stable locomotions through rough terrains.

Highlights

Compared with wheeled robots, bionic legged robots achieve better motion performances using discontinuous ground support.[1,2,3] For the goal of large load field transportations, legged robots in large size and weight are developed
The importance of heavy load robots walking on rough terrains with free gait is addressed
The main theoretical contribution of this article is the establishment of a free gait controller

Summary

Introduction

Bionic legged robots achieve better motion performances using discontinuous ground support.[1,2,3] For the goal of large load field transportations, legged robots in large size and weight are developed. If leg j is currently in the swing status and its target foot landing position in the coxal coordinate system is BDj, the kinematic margin of leg j in target support status can be expressed as shown in equation (9)

Results

Conclusion