A gait planning approach for locomotion stability of four-legged robots

In this paper, we present a method to plan gait for a four legged robot that we specially design for realizing stability locomotion. Gait is crucial to the four legged robot locomotion, especially when the robot intends to get through irregular terrains adaptively. Compare to six legged robot or more leg robot, four legged robot easily loses its stability and slip up. We firstly analyze the locomotion of four legged animal and get six typical gaits that animal frequently uses. Then, we propose an algorithm to get the first and second hip joint angle, knee joint angle according to the relation between foot workplace and gait which robot walk is used. Especially we analyze the stability margin of walk gait and give a method to change the stability margin when robot uses walk gait, this method can easily make four legged robot walk stability. Finally, we successfully demonstrate our method by a simulation.