나선형 파동유도관 결합을 통한 초음파센서의 탐지범위 개선

Abstract

This paper presents a method to improve the detectable range of an ultrasonic sensor for distance measurements by coupling the sensor with a helical waveguide. In particular, this study aimed to decrease the effective length of circularly curved waveguides, in addition to reducing the minimum and maintaining the maximum detectable distances. To this end, finite element analyses were used to predict the ultrasound propagation in a waveguide with a uniform circular cross-section along the spiral path. Two types of cross-sectional sizes were compared: one with a diameter identical to that of the sensor face and another with a diameter twice this value. Furthermore, experiments were performed with fabricated prototypes to evaluate the detectable range by measuring the minimum and maximum detectable distances. Notably, by coupling the helical waveguide with the ultrasonic sensor, the minimum detectable distance was reduced to 1/3 times that for a sensor without the waveguide, while the maximum detectable distance was maintained. Moreover, the effective length of the helical waveguide was decreased, as compared with that of linear or circularly curved waveguides.