Abstract: In order to prevent robot colliding to human, and improve robot safety during motion, a method of robot safe motion planning based on minimized danger index is proposed. The motion planning of robot is divided into four steps which include global path safe planner, real-time safe trajectory planner, real-time anti-collision controller and goal re-searching. The danger degree can be estimated based on the robot inertia, the distance and relative speed between robot and human during every planning step, and it described as danger index. The motion of robot can be planned by minimizing the danger index. A mathematic model including a 3 degree of freedom robot and human is established. Every motion planning step is simulated in Matlab. To further verify the validity of the planning algorithm, a safe motion planning experiment platform of industrial robot is established, and safe avoiding collision is realized based on minimized danger index. The simulation and experiment results show that this robot safe motion planning method based on minimized danger index is capable of ensuring human safety in coexistence environment of robot and human.

Key words: danger index, goal re-searching, real-time anti-collision control, robot safety, safe motion planning