Collision avoidance for a two-arm robot by reflex actions: Simulations and experimentations

This paper addresses the problem of collision avoidance between the two arms of a two-arm robot. In our case, the problem is solved through the reflex action theory. In fact, one arm is protected by virtual protection zones. When an unscheduled event occurs, in other words when the second arm is going to collide with the first one, the shape of the protection zones is modified. Then, a motion is computed for the first arm to rebuild the initial shape of the protection zones. The use of different shapes for the protection zones is explained and justified. Several strategies to compute the motion are proposed and discussed. Finally, this method is tested in simulation and on real experiments for different kinds of two-arm robots: planar manipulators, PUMA 560 robots and parallelogram robots.