Quadruped Robot with Reduced Number of Actuators

摘要

This paper describes a highly general discussion of the classification of the function of a quadruped walking robot, and necessity number of active degrees of freedom (DOF) for each function is revealed. Specific number of active DOF is shown for reduced function quadruped robots. For example, leg function of forward/backward/curve/turn on uneven terrain requires 2 DOF. Omni-directional walk on uneven terrain realizes by 3 DOF as for the leg function. Additional number of DOF contributes to control internal forces of the legs. Controlling internal pushing/pulling forces between 4 supporting legs requires 3 additional DOF on 3 DOF of swing leg. As for the body movement, controlling a center of the gravity (CG) in forward/backward, sideways, vertical directions requires 1 DOF individually. Body attitude control of two horizontal axes, and vertical axis requires 1 DOF each. Popular quadruped robot with 12 DOF is the one that have all above DOF. On the second, concrete mechanisms for reduced DOF quadruped are shown. A 3 DOF mechanisms for forward/backward/curve/turn locomotion on uneven terrain, and a 4 DOF one for omni-directional locomotion are designed. Latter one follows a more easily realistic 5 DOF design.A gait generating algorithm for reduced function quadruped is also shown. Finally, the experiments of trial manufactured 3 DOF and 5 DOF quadrupeds show a validity of discussions.