Signal Tuning of Observables at the Support of a Vibrissa-like Tactile Sensor in Different Scanning Scenarios

Rodents like rats and mice use their mystacial vibrissae for tactile perception. Several information of objects varying in (geometrical) size can be detected. For instance, the animals are able to recognize the shape of an object as well as to determine very fine surface textures by contacting the object with their vibrissae. The vibrissal kinematics differ in these tasks, the vibrissae can be brushed/swept against an object (protraction and retraction) or they can be dabbed against it. Here, a vibrissa inspired sensor (cylindrical spring steel wire) is swept along a rectangular object. Examining the influence of the displacement of the sensor support on the measured signals, translational and rotatory scanning scenarios are analyzed in simulations and experiments. In a first step, a frictionless contact between sensor and object is assumed. Then, friction is taken into account. In dependence on the scanning scenario the measured signal is amplified. Furthermore, the orientation of the sensor within one sweep is important in case of the frictional contact. The results imply that the scanning scenario and sensor orientation can be used to tune the measured signals.