거리측정용 초음파센서 음원생성부 설계에 관한 연구

A new highly-directional ultrasonic range sensor is proposed to detect an obstacle. In the sensor, the parametric acoustic array, a nonlinear effect of media between two intensive waves, is applied to improve directivity. Particularly, we introduce a novel method to model the tranducer part for generating high amplitude waves consisted of two frequencies. The model combines the continnum model of bar and the compatibility condition between a piezoelectric actuator and linear horn. By using the model method, we could design the transducer to utilize two emitting primary frequency. The proposed transduce has shows a HPBW of less than 5° at 40㎑ that is much higher directivity than general ultrasonic range spatial sensor. Also, we could check that it has a primary wave of more than 125 ㏈ and a secondary difference wave of 90 ㏈.