弯曲振动超声换能器在陆地自主车上的应用

Application of Flexural Vibration Ultrasonic Sensors to Autonomous Land Vehicle

因为作用距离较短,所以超声波传感器一般用于机器人低速运行在静态环境中进行的短距离测量,无法作为高速行驶陆地自主车的前视传感器来使用。为解决问题,根据超声换能器功率高、频率低时,发射的超声波衰减慢、传播距离远的原理,基于能改善传统压电换能器和磁致伸缩换能器的声匹配、提高气介式超声换能器辐射声功率及效率的弯曲振动换能器,研制了一种高功率、低频率、作用距离远的超声传感器,其波束角为9°,最大作用距离可超过35m,经实验测定,超声传感器在最大量程处测量数据稳定、指向性强,完全能够满足在高速行驶的陆地自主车进行远距离测距的要求。

Due to the short effective distance, the ultrasonic sensor is merely used for short distance measurement on a slowly moving robot in a static circumstance, and cannot be used as an anterior sensor for high speed Autonomous Land Vehicle. A long distance measurement ultrasonic sensor with high power and low frequency is presented, its beam angle is 9°, and the maximal distance is over 35m. It is based on two principles： first the attenuation of ultrasonic can be slower so the distance can be longer when the power is＇higher and frequency is lower; secondly the use of flexural vibration ultrasonic sensor can improve the sound matching of traditional piezoelectric transducer and magnetoconstriction transducer, besides, it can increase the sound power and efficiency of air - coupled ultrasonic sensor. The experiment indicates that the novel sensor can detect the object in 35m stably and the directivity pattern is good for detecting, so it can be used for long distance measurement on fast moving Autonomous Land Vehicle.