An Electro-pneumatic Shape Morphing Rolling Robot with Variable Locomotion Modes

Abstract

Mobile robots with accurate and fast rolling loco-motion capabilities would greatly enhance their adaptability in dynamic environments. Inspired by organisms capable of rolling locomotion, this paper presents a lightweight shape morphable rolling robot which integrates an origami skeleton with muscle-like pneumatic pouches as drivers and electroadhesion (EA) pads as anchors. The origami skeleton of the robot is a hexag-onal loop structure composed of polyethylene terephthalate (PET) panels with flexural hinges between them. Pneumatic pouch actuators are embedded between the panels to change the configuration of the skeleton. The flat panels of the origami skeleton house electroadhesion actuators which can adhere to different surfaces with different slopes and materials. Two sequential control schemes are proposed that enable the robot to move forward and backward accurately by controlling the air pressure in the pouches and voltage supplied to the EA pads. Using combined actuation of pneumatic pouches and EA pads, the robot is able to roll on both horizontal and inclined surfaces as well as transit from horizontal to fully vertical surfaces. The robot shows less than 1% error in positioning after one complete forward and backward rolling cycle. Owing to its use of thin sheet materials for skeleton and pouch actuators and EA pads, the robot is lightweight weighing only 25 g. These unique properties of the robot will enable the deployment of such versatile mobile robots to conduct tasks remotely in challenging environments.