Exploiting Distributed Tactile Sensors to Drive a Robot Arm through Obstacles

Robots operating in unstructured environments must be capable of safely handling unexpected collisions with objects existing in the surrounding area, possibly without stopping the task execution. This letter proposes a tactile feedback control law allowing the robot to apply bounded contact forces in reaction to physical collisions while performing a task. As a use-case scenario, the problem of driving a robot arm through obstacles to reach a known target position in the space is considered. Intensities and locations of multiple and simultaneous contacts between the robot and the environment are detected using large area tactile sensors covering the robot body. It will be shown that the robot is capable of controlling the end-effector position and of reacting to unexpected collisions by regulating the interaction forces applied to the environment. The method has been validated on a Baxter robot partially covered with 3495 distributed tactile elements, operating in an unknown environment.