Inertial Propulsion Robot Using the Shape Characteristics of a Streamlined Body Frame

Abstract

We have been investigating a crawling-like loco-motion robot to make it efficiently slide forward based on a simple system and control mechanisms on a slippery level surface, where the motion of the center of mass plays an important role. In this paper, we induce an effective motion of the center of mass considering a streamlined body shape of a locomotion robot in which a pendulum is installed. First, we derive the equation of motion and a control input to achieve a desired motion of the inner pendulum. Second, we formulate constraint conditions between the streamlined body and a slippery floor. Third, we demonstrate the numerical simulation, and the robot steadily slides forward by adopting the streamlined shape as the body frame. Fourth, we verify the numerical results through experiments, and the experimental results exhibit a similar tendency compared with the numerical results. Fifth, we find a local minimum value of locomotion efficiency based on Bayesian optimization which is a class of machine-learning-based optimization, and we achieve exceedingly efficient locomotion of the robot on the slippery floor at the local minimum in both the simulation and experiment.