Biomimetic leg design for untethered quadruped gallop

摘要

Ohio State and Stanford Universities are cooperating to better understand quadrupedal galloping through the design of a self-contained quadrupedal robot. The leg for this quadruped was first designed at Ohio State University (OSU). A second-generation leg is being tested at Stanford University. The Stanford leg incorporates important characteristics of a quadruped leg. These characteristics are grouped into three categories: biomimetic design, design for simulation and control, and design for experimentation. Important biomimetic design characteristics include minimal impact loss, elastic energy storage, and low inertia. Important characteristics for simulation and control include freedom from tether forces, high structural rigidity, and uncoupled actuation. To facilitate experimentation, the leg should resist the vibration of constant galloping, and be rapid to fabricate. The Stanford leg design is intended to improve on the OSU leg design with respect to these characteristics. Two improvements are most significant. The cable linkage, which works against a large spring to flex the knee, has been uncoupled from the front-to-back hip actuator. By using design and construction techniques common to the light aircraft industry, the stiffness of the leg structure has increased while the mass of the leg has remained constant. 1