Abstract
Vibration-driven locomotion systems can be used to design microrobots, and improving locomotion performance has been one of the research focuses. Integrating the bistability and the vibration-driven mechanism to enhance the locomotion performance of the robot is investigated in this paper. A three-module vibration-driven locomotion robot connected by two bistable pre-buckling beams is designed and modeled as a nonlinear lumped-mass system. Due to the discontinuity caused by the dry friction, numerical approaches are employed in this research, which not only reveals the effects of the actuation parameters on the bistable dynamics and the steady-state locomotion of the robot, but also uncovers the unique merits that the bistability brings to the robot. On the one hand, results reveal that the robot exhibits different locomotion modes corresponding to different levels of the average steady-state velocity. By changing the initial conditions of the system, the robot can fast-switching between different locomotion modes. On the other hand, the robot can adapt to variable payloads and maintain effective locomotion, which is an advantage that traditional linear systems do not have. The findings of this paper would provide a design basis and useful guidelines for the development of bistable vibration-driven locomotion robots, which will advance the state of the art.
