COMPlacent: A Compliant Whisker Manipulator for Object Tactile Exploration

Handling fragile objects requires minimally invasive interaction skills in order to avoid any permanent deformation, alternation or damages. Such need is often required in tactile exploration tasks. In this paper, we propose an innovative whisker manipulator (COMPlacent), which is designed to accomplish tactile exploration with minimum intrusiveness. The design is inspired by biological whiskers observed in animals, where whiskers are used as means of tactile exploration in an analogous way as fingers are. Artificial whiskers are compliant but robust, which mitigates contact forces by bending or conforming to the object surface. The intrusiveness is further reduced by reactive control, which is implemented based on tactile sensors and actuators installed on each whisker. This allows the whisker to be retracted from the object surface, so that the energy transferred by contacts is minimized. The tactile sensor is designed to be ultrasensitive, which allows it to gather contact information with high fidelity. By modeling contact pressure as a time-series signal, a machine learning framework is leveraged to discriminate object properties including shape and texture. Evaluation experiments were conducted on real objects, which successfully demonstrates object classification at an accuracy of 97.3%, and texture discrimination accuracy of 92.1%.