An Optical Tactile Sensor for Measuring Force Values and Directions for Several Soft and Rigid Contacts

Abstract:
The implementation of robots to manipulate with soft or fragile objects requires usage of high sensible tactile sensors. For many applications, beside the force magnitude, the direction is also important. This paper extends already available ideas and implementations of 3D-tactile sensors. Our sensor can detect a wide range of forces, the direction of forces and shifting forces along the sensor surface for several contact points simultaneously. The amount of capabilities in a single sensor is unique. The underlying concept is a pressure-to-light system. A camera provides images of a structure, which generates geometric shapes on the images according to external acting forces. The shapes are well convenient for image processing and give the ability to use them as reference for the forces. After describing our approach very detailed we show experiments for evaluation, e.g. applying it to grab objects carefully. Finally the future work is discussed, where we plan to bring the sensor to anthropomorphic robot hands.