Hydraulic-driven soft robot for entering into small gap fed by indirect information of contacting state

Abstract

The soft robot which has an elastic body has increased interest because of its prospects with regard to entering into small gaps such as in rubble by deforming the body according to a contacting object like an amoeba. One of the issues regarding the soft robot is the locomotion ability and another is effective usage of an appropriate sensor because the present actuator or sensor has a rigid body that prevents the deformation of the robot. This paper describes water-driven robot that generates friction locally to kick or pull the body, and it explains indirect sensing for the soft robot. A water pressure sensor is adopted to indirectly measure the contact information, and is attached near the flexible body. Because the sensor does not prevent deformation by setting an appropriate position, the body can deform according to a shape of a contact obstacle, and the sensor indicates a difference in the shape of the obstacles by moving under the obstacle. The paper also describes a feedback controller by using the pressure information that avoids break of the body inflated by water.