Use of mechanical impedance in sensing object-end effector interaction

This paper outlines an innovative approach for the on-line sensing of mechanical impedance at the interface of a robotic end effector and an object that is being manipulated or processed. Motor current and the displacement encoder signals of the effectors may be processed to obtain the impedance information. A model for the mechanical interactions between the end effector and the object is developed. The model is useful in model identification, model-based control, and performance evaluation. The prototype system is described and typical experimental results using an industrial robot, are presented