Wirelessly interrogable surface acoustic wave sensors for vehicular applications

Abstract

Wirelessly interrogated passive surface acoustic wave (SAW) sensors for measurements in a rough environment are shown. These can be applied when remote readout is necessary and other sensors cannot withstand heat, dirt, mechanical vibration, and/or electromagnetic interference. Applications of passive SAW sensors for sensing tasks, especially in vehicles are discussed. The implementation of SAW sensors for measurements of torque and speed of revolution on transmission shafts is discussed. We present measurements of railway disc brake temperature by on-disc SAW sensors and wireless measurement of the air pressure in the tires of road vehicles in motion. The applied SAW sensors, the corresponding interrogation systems and an algorithm for signal processing are described. Estimations of measurement errors and results of measurements are discussed.