The Relationship Between Incremental Changes in Orientation and Slip Speed Estimation Using the Fingerprint Effect

The fingerprint effect, wherein vibrations are produced with frequencies related to the speed of a surface sliding across fingerprint ridges and the period of those ridges, has been studied for use in both slip detection and texture recognition. Here, we use a simple bioinspired sensor with parallel, straight, fingerprint-like ridges and a single ferroelectric ceramic transducer to show that the fingerprint effect is orientation dependent and that, if the orientation is known, it can be used to estimate slip speed. Our results, obtained at sliding speeds of 15 mm/s, 20 mm/s, and 25 mm/s and orientations from 0° – 90°, clearly demonstrate this dependence. Additionally, we use our results to run a simulation, using MATLAB software, of real-time slip speed estimation. The simulation shows that the fingerprint effect can be used for real-time slip-speed estimation.