Dynamic Collision Avoidance of Industrial Cooperating Robots Using Virtual Force Fields

This article presents an approach to dynamic collision avoidance of industrial robots working in a shared workspace. It is based on artificial potential or force fields generated by virtual charges which are placed on the moving obstacles e.g. on other manipulators. The positions of the charges will be calculated in real time using CAD data of the obstacles and measured values of its positions. Between different groups of virtual charges artificial forces act on manipulators and hinder their collision by shifting robot motions. This is performed by means of impedance control. The artificial forces acting on the robot generate position offsets in the manipulator path defined by target impedance. All algorithms are implemented with a real robot system and experimental results are presented.