Graph-Based Potential Field For The End-Effector Control Within The Torque-Based Task Hierarchy

In the article, a reactive torque-based hierarchical task-space control for a robot with multiple redundant DOFs is presented that is suitable to plan, validate and execute a humanoid upper-body motion in human oriented environment. The strategy consists of: (i) joint limit avoidance, (ii) self-collision avoidance using repulsive force fields with additional environment collision avoidance, (iii) end-effector task with a specified discrete potential field with tricubic interpolation and (iv) a posture task on the lowest priority. The proposed approach is verified for Velma - a robot with a humanoid upper-body.