Development of Particle Flow-Based Inflatable Robot Body for Shape Rigidity Modulation

Disaster robots are needed to perform various tasks through narrow gaps between building debris to be used for rescue. A soft material-based disaster robot can have easy access to the rescue site through the narrow gaps. To ensure the robust control and better performance of the soft robot operation, a joint stiffness modulation mechanism is required. In this paper, we have proposed a noble stiffness modulation mechanism that includes shape change and self-assembly by using a particle flow-based inflatable robot body. We analyzed the particle filling completion time by injecting air and particles at a constant pressure into the soft chamber depending on several parameters (the size of the particle, the size of the reservoir, the volume ratio between the chamber volume and the total volume of the particle, and the injected air pressure). Of these, the most dominant factors influencing the completion time were particle size and pressure. It was observed that the smaller the size of the particle, the shorter time. The completion time tended to decrease as the air pressure increased.