Slip detection of robotic hand based on vibration power of pressure center

This paper proposes an incipient slip detection method for a robotic hand based on the vibration power of the pressure center. Firstly, an array-type pressure sensor was planted into the soft skin of the robotic hand to measure the stick-slip vibration component of the pressure center generated in the process of slip of the grasped object. Secondly, the vibration power of the pressure center was calculated based on the measured stick-slip vibration component, and was used as a slip-detection function to judge the incipient slip of the grasped object. Finally, in order to use the same threshold value to judge incipient slip for different grasping forces, a weight coefficient was experimentally identified and used in the slip-detection function. The effectiveness of the proposed slip detection method was verified by experimental results, which showed that incipient slip can be detected by the proposed slip-detection function with the same threshold value for various materials, different slipping speeds grasping forces. In addition, multiple iterations of the experiment had demonstrated that the slip detection is repeatable.