The effect of whisker movement on radial distance
estimation: A case study in comparative robotics

Abstract

Whisker movement has been shown to be under active control in certain specialist
animals such as rats and mice. Though this whisker movement is well characterized,
the role and effect of this movement on subsequent sensing is poorly understood. One
method for investigating this phenomena is to generate artificial whisker deflections with
robotic hardware under different movement conditions. A limitation of this approach
is that assumptions must be made in the design of any artificial whisker actuators,
which will impose certain restrictions on the whisker-object interaction. In this paper
we present three robotic whisker platforms, each with different mechanical whisker
properties and actuation mechanisms. A feature-based classifier is used to simultaneously
discriminate radial distance to contact and contact speed for the first time. We show
that whisker-object contact speed predictably affects deflection magnitudes, invariant
of whisker material or whisker movement trajectory. We propose that rodent whisker
control allows the animal to improve sensing accuracy by regulating contact speed induced
touch-to-touch variability.