Progressive Automation of Repetitive Tasks Involving both Translation and Rotation

Progressive automation aims at quick and easy programming of repetitive tasks by means of kinesthetic demonstration from an operator. In this paper we address the general case, where the operator demonstrates a task involving motion of both the robot’s wrist position and its orientation, so that the robot progressively transitions from manual into autonomous operation based on the agreement level between consecutive demonstrations. Utilizing unit quaternions, we propose a method that combines dynamic movement primitives for encoding the task space motion with variable stiffness control for continuous role allocation, enabling an operator to easily program task by demonstration. We verify experimentally that a pick and place task with changes in the position and the orientation can be programmed with the proposed method in less than a minute.