A Biologically Inspired Passive Antenna for Steering Control of a Running Robot

Inspired by nature’s effective use of tactile feedback for rapid maneuvering, we have designed a passive, highly compliant tactile sensor for Sprawlette, a hexapedal running robot. To bridge the gap between between biology and design, we have taken initial steps toward understanding how the cockroach, Periplaneta americana, uses antenna feedback to control its orientation as it runs along a wall. First, we have developed a simple template model for antenna-based wall following. Our model indicates that a naive proporitional (P) controller based purely on headto-wall distance may not be sufficient to stabilize rapid locomotion. However, the model can be stabilized with additional feedback based on the rate that the roach is converging to or diverging from the wall. This rate, or “tactile flow” information can be incorporated into a proportional-derivative (PD) style controller. To test the Pvs. PD-control hypotheses, we have collected initial cockroach data that seems to support the idea that the rate of convergence to the wall is indeed being used for controlling body orientation. Based on the model, and on our initial observations of the cockroach, we have designed and calibrated our tactile sensor to measure Sprawlette’s angle and distance relative to a straight wall. Empirically, stabilizing Sprawlette during wall following does indeed require tactile flow, as predicted.