Influence of Vibrissa Morphology on Artificial Tactile Sensors for Surface Texture Detection

Abstract

AbstractAnimals, e.g. rats and cats, have different types of tactile hairs. One type are the mystacial vibrissae. They are located around the snout and in combination with the follicle‐sinus complex they are powerful tactile sensors. With them, animals are able to detect the distance to an object, recognize the object shape and determine the surface texture. Adapting the natural example, the goal is to design an artificial tactile sensor with a similar functionality. In the course of this, a model for surface texture detection is developed. The vibrissa is modeled as an Euler‐Bernoulli bending beam, incorporating large deflections. The contact, between vibrissa and surface, is modeled using Coulomb's law of friction. The mechanical modeling results in a nonlinear, system of first order differential equations. Solving the boundary‐value problem by applying a shooting method, a quasi‐static simulation is performed. Some first relations between the vibrissa morphology and the surface contact are analyzed. With view to an artificial sensor, the change of the reaction forces and moments at the base of the vibrissa due to the surface contact is the point of focus. Out of the reaction forces, the coefficient of static friction between vibrissa and surface is determined. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)