Stable walking of a quadruped robot on uneven terrains with friction constraints

One of advantages of legged robots rather than wheeled robots is their mobilability on uneven terrains. To achieve reliable motion and improve performance characteristics of these robots in such environments, COG path planning is one of the main issues which must be taken into account. In this paper, a new stability criterion is introduced to ensure the robot stability on uneven terrains. To avoid feet slippage, the friction cone is approximated by a pyramid and is applied into optimization problem leading to a linear form. The validity of the proposed algorithm is performed by simulation analysis of a quadruped robot.