A spatial single loop kinematotropic mechanism used for biped/wheeled switchable robots

In this paper, we propose a novel biped walking robot on the basis of a spatial eight-bar mechanism. The kinematotropic characteristic of the mechanism is investigated and the geometric constrains deriving the kinematotropy are specified. The mechanism possesses two motion branches with different degrees of freedom. A detailed kinematic analysis is presented for both motion branches. A biped/wheeled switchable robot is further designed. In the motion branch I, the mechanism is used as a biped walking mechanism. In the motion branch II, it is utilized as a wheeled robot and completes the switch process between two modes. At last, we demonstrate the gait motion of the robot in the biped mode and the switch process.