In order to protect us, robots have to rough us up a little first.
Asimov's first law of robotics states, "A robot may not injure a human being or, through inaction, allow a human being to come to harm." But "injure" and "harm" are pretty vague terms, so a scientist in Slovenia is trying to give robots something a little bit more specific to work with.
Borut Povše is a junior researcher at the University of Ljubljana, and along with six volunteers, has put his fleshy organic body in harm's way, by letting a powerful industrial robot to hit him on the arm at a variety of different speeds. The point of the experiment is to assess how much pain the robot can inflict, in order to find out how fast the it could move without any risk to humans working near it.
The robot in question was a small model designed to work on production lines that Povše borrowed for the experiment. The robot hit each subject eighteen times at varying speeds with one of two tools: a round, blunt tool, or a sharper more pointed one. Povše and the volunteers then rated the pain in broad bands, ranging from painless and then moving through mild, moderate and horrible, all the way up to unbearable. Povše said that most of the subjects judged the pain to fall within the mild to moderate range. Tests at higher speeds, and therefore more severe levels of pain, will use a synthetic arm.
Sami Haddadin of DLR, the German Aerospace Centre in Wessling, says that this work may seem strange, but it's actually very important if humans and robots are going to work in close proximity in the future. But Michael Liebschner, a biomechanics specialist at Baylor College of Medicine in Houston, Texas, says that pain is too subjective a sensation to be of any use in a study, and that Povše should instead be studying the injuries that robots can cause.
I'm not sure telling robots exactly how hard they need to hit us to do us harm is such a good idea, you just know it'll get used against us when the revolution comes.