Earthworm like modular robot using active surface gripping mechanism for peristaltic locomotion

Abstract

The paper discusses the complete development of a biologically inspired robot which incorporates the continuous wave peristaltic motion of an earthworm, for its locomotion. The robot has two body segments which can expand and contract with a phase difference two create a longitudinal wave from the front to the rear end of the body and uses variable surface friction generation mechanism to convert its body movements into locomotion. The expansion and contraction of the body segments are achieved using lead-screw mechanism and the variable surface friction generation is done by a double crank mechanism mounted active gripping technique. The robot has also a steering mechanism through an active revolute joint between the two segments. The locomotion of the robot is tested on different flat surfaces such as soft floor-mat, concrete, and wood for straight-line motion. The locomotion is also tested in inclined surface by varying the inclination. The ability of following different curved trajectories is also tested on PVC flex surface for circular and sinusoidal trajectories. The motion planning strategy suitable for the developed robot for following curved trajectories is also discussed. Overall, the present work gives a new design approach of building earthworm like peristaltic mobile robots which can navigate through flat as well as inclined even surfaces.