Joint space position/torque hybrid control of the quadruped robot for locomotion and push reaction

Abstract

This thesis proposes an algorithm for Joint space position/torque hybrid control of a mammal-type quadruped robot, and presents experiments to verify its performance. With this control algorithm, the robot could conduct both locomotion and push reaction without fully torque controlled. Based on the natural friction dynamics of the legged robot, we showed that reaction to a typical push in horizontal direction does not require full force control in the frontal plane. Furthermore, the joint configuration of the mammal-type quadruped robot makes position/force hybrid control in Cartesian space can be directly corresponded to Joint space position/torque hybrid control. We conducted experiments to show that this approach is effective to stabilize the robot while it is walking and being disturbed by push. From the result, we can conclude that the mammal type quadruped can be designed without torque controllability of Hip roll joints, which can have much more joint design option, while locomotion and push reaction capability of total system is remained.