New-Tech Europe Magazine | May 2016

imagine the robot saying “Ouch!” louder and louder each time: The robot’s tactile system is using a “nervous robot-tissue model that is inspired by the human skin structure” to decide how much pain they should feel for a given amount of force. Just like human neurons, the model transmits pain information in repetitive spikes if the force exceeds a certain threshold, and the pain controller reacts after classifying the information into light, moderate, or severe pain. In the [light] pain class, such contacts occur that may harm the robot or prevent it from performing the task. The robot “feels” uncomfortable and shall smoothly retract until the contact event is over and return thereafter. Strong collisions are covered in the [moderate] pain class. The robot “feels” moderate pain, shall quickly retract, and more distant until the contact event is over. Then, it may move back. The [severe] pain class covers all contacts in which the robot may be damaged and thus needs some sort of “help”. In order to prevent making the damage worse, the robot switches to gravity compensation with additional damping for dissipation, improving the safety of the robot and the environment by its strictly passive behavior. In terms of both bio-inspiration and control, this paper is just the first step towards a pain-based reflex controller for robots, but as sinister as it sounds, it’s something that most robots could get a lot of use out of, especially given the overall increase in robot autonomy and collaboration with human workers. Keeping robots from hurting people is certainly a top priority, but even Asimov would agree that keeping robots from hurting themselves is also important if we want to have them around us. “An Artificial Robot Nervous System to Teach Robots How to Feel Pain and Reflexively React to Potentially Damaging Contacts,” by Johannes Kuehn and Sami Haddadin from Leibniz University in Hannover, was presented last week at ICRA 2016 in Stockholm, Sweden. Leibniz University of Hannover Evan Ackerman

states and disturbances, rate the potential damage they may cause to it, and initiate appropriate countermeasures, i.e., reflexes. In order to tackle this demanding requirement, the human antetype shall serve as our inspiration, meaning that human pain-reflex movements are used for designing according robot pain sensation models and reaction controls. We focus on the formalization of robot pain, based on insights from human pain research, as an interpretation of tactile sensation. This video shows a prototype of the controller running on a Kuka arm equipped with a BioTac tactile fingertip sensor (it can sense pressure and also temperature). I find that it helps if you

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