Artificial Tactile Sensor With Pin-type Module for Depth Profile and Surface Topography Detection

Abstract

Haptic sensors based on piezoelectric sensor arrays with pin-type modules which have high responses and dynamic sensing capabilities are designed and studied for surface topography measurements. Unlike the human finger, most flexible tactile sensor designs do not detect the depth information of surfaces well, which change at the mm level despite the fact that they have a good sensitivity for pressure or force. To enhance the ability to detect depth information of the surfaces of objects, a piezoelectric sensor combining a pin-type module with excellent monitoring in the depth direction by spring is developed in this paper. Because spike types of piezoelectric signals do not match a specific surface topography directly, a signal processing method that reconstructs the surface topography is studied considering the piezoelectric working principle and spring dynamics. According to the sensor design, it can detect 3 mm depth changes with a two-dimensional plane structure at mm-level resolutions. The results show that the proposed sensor could measure various shapes and depth profiles precisely via a sliding motion, and the surface topography is reconstructed through highly accurate measurement results, similar to a human.