Design and Prototyping of a Shape-Changing Rigid-Body Human Foot in Gait

Abstract

Traditional ankle-foot devices such as prostheses or robotic feet seek to replicate the physiological change in shape of the foot during gait using compliant mechanisms. In comparison, rigid-body feet tend to be simplistic and largely incapable of accurately representing the geometry of the human foot. Rigidbody mechanisms offer certain advantages over compliant mechanisms which may be desirable in the design of ankle-foot devices, including the ability to withstand greater loading, the ability to achieve more drastic shape-change, and the ability to be synthesized from their kinematics, allowing for realistic functionality without a priori characterization of the external loading conditions of the foot. This work focuses on applying the methodology of shape-changing kinematic synthesis to design and prototype a multi-segment rigid-body foot device capable of matching the dynamic change in shape of the human foot in gait.