Ultrasonic resonators are used as sensors in a variety of applications. They are relatively small and very suitable-for measuring distance, because the ultrasonic wave length is short.
In vehicles, ultrasonic resonators are used as a “Back Sonar,” which monitors the rear of the vehicle as a driving assistance system. Based on market demands for the capability to monitor the vehicle's circumference and also its four corners, ultrasonic wave technology has been further developed.
This paper introduces ultrasonic sensors and other related technologies that have been applied to the development of the vehicle circumference monitoring system.