ThermalSkin: A Distributed Sensor for Anemotaxis Robot Navigation

Abstract

This paper presents a biomimetic thermal anemometer called ThermalSkin to measure airflow intensity and direction around solid structures. The ThermalSkin airflow sensing system is based on the information provided by a network of small thermal anemometers (thermal "scales") placed around an airflow deflecting structure. This approach is inspired by the wet finger approach used by old men to estimate the direction of the wind. In this method, the coldest part of the finger (the part with higher thermal dissipation rate) points in the upwind direction. Although the system has been developed for robotics, its principle is general allowing a straight adaptation for most applications requiring the measurement of fluid intensity and direction around a solid body. The scale elements are smart thermal anemometers able to measure the wind intensity near their surfaces. Each scale is composed by a constant temperature self-heated thermistor, the respective signal conditioning circuit and a Microchip PIC microcontroller that interfaces with a LIN-based network. The simple (3-wire bus) and smart structure of the system provides a framework easy to set-up and calibrate. A central controller gathers data from each sensing element and estimates the local airflow vector.