Using intentional contact to achieve tasks in tight environments

Skin technology enabled a powerful way to sense the environment in robotic systems. It allows simplifying the formulation of safety tasks such as collision avoidance between the robot, the environment and surrounding objects. In this paper, a hierarchy policy based on tactile feedback is proposed to let a robot interact with its environment while performing a set of tasks. Such policy lets the safety tasks as collision avoidance and physical interaction, be reduced to simple potential field rules fed directly with tactile feedback which keeps computation demand low. In this context, the concept of 'Intentional Contact' is introduced to escape from classic undesired equilibrium points produced by local minima in the potential fields. Allowed contact with the environment empowers a robot to modify its surroundings in order to fulfil the main task. Such contact is permitted as long as the generated force remains under a specific limit, otherwise, a reactive action is taken to reduce it. This new concept is validated in simulation and on a real robot.