Track-Linkage-Based Compliant Robot for High Obstacle Overcoming Capability With Stable Motion

Abstract

In this study, we proposed a track-linkage mechanism, comprising an inverse 4-bar linkage with a compliant link aimed at enhancing stability and mobility when overcoming high obstacles. Previous track mechanisms demonstrate high obstacle traversal performance; however, significant variations in the height and pitch of the main body's center of mass result in unstable movement. To address these issues, the X-Track was introduced, designed to effectively overcome high obstacles without requiring additional motor control or sensors. Stability was analyzed through kinematics, and the relationship between stiffness and mobility was confirmed through quasi-static analysis. Multibody dynamics simulations were conducted to evaluate the mobility and stability of the X-Track. The reliability of the simulation was validated through prototype experiments, and mobility was confirmed through field tests of actual stairs. In future work, by optimizing the velocity for each track based on changes induced by ground contact, increased mobility and stability are expected.