End-effector obstacle avoidance using multiple dynamic variables

Generating flexible collision-free reaching movements is a standard task for autonomous articulated robots that is critical especially when such systems interact with humans in a service robotics setting. Current solutions are still challenging to put into practice. Here we generalize an approach first used to plan end-effector movement that is based on attractor dynamical systems. We show, how different contributions to the motion planning dynamics can be formulated in constraint-specific reference frames and then transformed into the frame of the joint velocity vector. We implement this system on an 8 DoF redundant manipulator and show its feasibility in a simulation. A systematic experiment with randomly generated obstacle scenes characterizes the performance of the system. Especially challenging configurations of obstacles are discussed to illustrate how the method solves these cases.