Design of a redundantly actuated hip mechanism

Abstract

In humanoid robotic system, many human-body motions such as walking, running, and jumping require large power. As one effort to achieve such high power-to-weight ratio, this paper proposes a new hip design using parallel kinematic chain involving redundant actuators. The kinematics for the hip mechanism is derived and a kinematic index to measure force transmission ratio is introduced. It is demonstrated through simulation that incorporation of redundant actuator into the hip mechanism enhances the power of the mechanism approximately 4 times of the minimum actuation. And the validity of the simulation result was verified through experimental works. Copyright © 2006 by The Japan Society of Mechanical Engineers.