A Boundary-Constrained Swarm Robot with Granular Jamming

This paper describes a new type of compliant and configurable soft robot, a boundary-constrained swarm. The robot consists of a sealed flexible membrane that constrains both a number of mobile robotic subunits and passive granular material. The robot can change the volume fraction of the sealed membrane by applying a vacuum, which gives the robot the ability to operate in two distinct states: compliant and jammed. The compliant state allows the robot to surround and conform to objects or pass through narrow corridors. Jamming allows the robot to form a desired shape; grasp, (a) manipulate, and exert relatively high forces on external objects; and achieve relatively higher locomotion speeds. Locomotion is achieved with a combination of whegs (wheeled legs) and vibration motors that are located on the robotic subunits. The paper describes the mechanical design of the robot, the control methodology, and its object handling capability.