On compensation of passive joint friction in robotic manipulators: Modeling, detection and identification

The progress made in friction compensation in robotics was concentrated on friction losses in the actuated joints. Today new mechanisms with a considerable number of passive joints, such parallel manipulators are emerging. This paper opens the discussion on the influence of passive joint friction (PJF) in robot´s dynamics and its impact on control performance. It gives a basic framework on the modeling, detection and identification of such phenomena. All proposed methods pass on additional sensors and use only the actuators for detection and compensation. Due to its dependency on the robot´s configuration, even small magnitudes of PJF can affect the system behavior, especially at unfavorable poses. To the best knowledge of the authors, the problem of PJF-compensation was not addressed systematically in literature yet