title: Design of an ultrasonic sensor for measuring distance and detecting obstacles.
abstract: This paper introduces a novel method for designing the transducer of a highly directional ultrasonic range sensor for detecting obstacles in mobile robot applications. The transducer consists of wave generation, amplification, and radiation sections, and a countermass. The operating principle of this design is based on the parametric array method where the frequency difference between two ultrasonic waves is used to generate a highly directional low-frequency wave with a small aperture. The aim of this study was to design an optimal transducer to generate the two simultaneous longitudinal modes efficiently. We first derived an appropriate mathematical model by combining the continuum model of a bar and countermass with the compatibility condition between a piezoelectric actuator and a linear horn. Then we determined the optimal length of the aluminum horn and the piezoelectric actuator using a finite element method. The proposed sensor exhibited a half-power bandwidth of less than+/-1.3 degrees at 44.8 kHz, a much higher directivity than existing conventional ultrasonic range sensors.
authors.affiliation: Department of Mechanical Engineering, Changwon National University, 9 Sarim-dong Changwon, Gyeongnam 641-773, Republic of Korea. chong@changwon.ac.kr
authors.forename: Jongkyu
authors.initials: J
authors.lastname: Park
authors.forename: Yub
authors.initials: Y
authors.lastname: Je
authors.forename: Haksue
authors.initials: H
authors.lastname: Lee
authors.forename: Wonkyu
authors.initials: W
authors.lastname: Moon
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D011825:Radar / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*