Quadruped Walking Robot with Reduced Degrees of Freedom

Abstract

We advocate the effectiveness of a walking robot to have a structure with a reduced DOF, not based on a model of real animals, to make the robot lightweight and practical, and discuss a technique for reducing the active degrees of freedom (DOF) of a quadruped walking robot as an example for realizing such objectives. If functions required of a quadruped walking robot are properly organized and the required active DOF is examined, 4 active DOF make it possible to select an arbitrary position on uneven terrain and to move in all directions. We describe a mechanism with 4 active DOF and 2 passive DOF as an example of concrete configurations for quadruped walking robots with 4 active DOF. A robot with a reduced active DOF, namely with 3 active DOF and 2 passive DOF, has a capability to reach an arbitrary position at an arbitrary angle on uneven terrain. An actual mechanical model was manufactured as an experimental model, and a walking experiment was conducted. The mechanical model turned out to be about one-4th in weight compared to a conventional biomimetic model of the same size. Based on the walking experiment, it was confirmed that this mechanical model can carry a load up to 4 times its own weight.