Active Touch with a Biomimetic 3D-Printed Whiskered Robot

We propose a new design of active tactile whiskered robot: the actuated TacWhisker array, analogous to motile tactile vibrissae such as the rodent macrovibrissae. The design is particularly simple, being completely 3D-printed, only having one motor to actuate all 10 whiskers, and utilizing optical tactile sensing to transduce whisker deflections into bending moments. This robot is used to investigate active touch on a simple localization task where the robot seeks to move the whisker array to centre on a stimulus while perceiving its location. Active localization with a threshold-crossing decision rule was found to rapidly improve the perceptual errors with successive whisks. Curiously, although the sensing is dominated by the whisker motion, this does not appreciably affect performance on this simple task. Overall, the robot promises to give a simple embodiment of whisker-based active touch to give insight into the mechanisms underlying perception in the mammalian brain.