Novel method of gait switching in six-legged robot walking on continuous-nondifferentiable terrain by utilizing stability and interference criteria

Continuous-nondifferentiable terrains are extremely challenging for the environment adaption of six-legged robots. Previous researches have focused on gait planning methods to improve inherent ability of legged robots to walk over moderate terrains.However,most six-legged robots utilize relatively monotonic gait so that they still cannot well adapt tough terrains. As a result,the current legged robots easily get stuck and fall when encountering continuous-nondifferentiable terrains,such as stairs.Therefore,a method of gait switching is proposed so that six-legged robots can flexibly generate multiple gaits to adapt complex terrains. This study investigated the relationship between six-legged robot gait topologies and physical constraints,such as robot stability and robot-terrain interference. The proposed gait switcher can generate 0-6,1-5,2-4 and 3-3 gaits,which is instructed by the stability and interference criteria. Simulations and experiments were performed on a novel six-legged robot Hexa-XIII that succeeded climbing stairs over 45°. The effectiveness of the gait switching method is validated by the experiment results.