Smart Highways-Based Piezoelectric Vehicle Speed Sensor

Abstract

In this chapter, the authors proposed a piezoelectric based vehicle speed sensor. The sensors produce pulses when stressed by a vehicle's front and back wheels, passed over them. Due to the vehicle physical dimension, the sensor pulse, due to the back wheel stressing, has some delay time as compared with the front wheel sensing pulse, due to the front wheel stressing. The time delay between these pulses is estimated using microcontroller program. Then, the program computes the vehicle speed from the distance to time delay ratio.