Design and Analysis of a Novel Planar Robotic Leg for High-Speed Locomotion

This paper presents the mechanical design and analysis of a novel leg mechanism that has only one active degree of freedom (DOF). The proposed mechanism is intended towards simplifying the mechanical and control complexity identified with the robotic legs implemented on quadrupedal platforms capable of dynamic locomotion. First, a survey of high-speed and reduced DOF legged robotic systems is presented to elucidate the design challenges and determine system requirements. Drawing from these requirements, a novel design of a six-bar leg mechanism with a single DOF is proposed. The novelty of the mechanism lies in its ability to trace a path that accommodates the execution of trot-gait by the quadrupedal platform realized by integrating the proposed leg. The kinematics of the mechanism is formulated and a multi-body model is used to perform a series of case studies on the sensitivity of the foot trajectory to the leg's dimensional parameters. Preliminary work on optimization of the foot trajectory is then performed. This research will ultimately assist the future design of quadrupedal robots to test the ability of spatial robotic tails in stabilizing and maneuvering the platform.