Passive sensing and active sensing of a biomimetic whisker

Rodents demonstrate an outstanding capability of texture discrimination and shape recognition with their whiskers (vibrissae). Many neurophysiological and behavioural studies reported that active whisking plays a critical role on tactile perception. However, the role and limitation of passive sensing has not been studied in detail. In this paper, we compare passive sensing and active sensing for distance estimation. Our experiments reveal that the estimation of force or contact distance through passive sensing is significantly impaired by noisy sensor readings of deflection angles, and so it is hard to obtain high-fidelity information about force and distance. In contrast, active sensing by whisking or robot movement provides precise distance information.