超音波定位系統與定位誤差分析

Ultrasonic Positioning System and Deviation Analysis

盧樹台(Shuh-Tai Lu)

《先進工程學刊》 3卷1期 (2008/01) Pp. 21-28

https://doi.org/10.29948/JAE.200801.0004

摘要

本論文提出一種創新的超音波感測系統，可以計算出凌空障礙物的座標位置，以協助盲胞做凌空障礙物的感測與預警。此種超音波感測系統是利用三個超音波接收器，安排成直角等腰三角形排列，並且在直角三角形斜邊的中央放置一個超音波發射器。超音波感測系統配合發射和接收電路，再經由三個超音波接收器所接收的回波訊號時間差，可以計算出凌空障礙物的座標位置。由於超音波在空氣中衰減速度快，加上溫度與濕度都可能會造成測距誤差，影響凌空障礙物的座標計算。因此，本論文採限定在盲人前方1至2公尺、±15度的範圍內，探討此超音波感測系統的測距誤差，與計算凌空障礙物座標所產生誤差的影響，以作為後續實作系統之參考。

關鍵字

超音波 ； 位置測量 ； 誤差分析

並列摘要

A novel positioning system is introduced in this paper. With the help of the system the blind can get early warning of where the obstacle is. The system has three ultrasonic sensors and an ultrasonic emitter. Three sensors are located at different apex of a right triangle and an ultrasonic emitter is located at center of hypotenuse. With the circuits of emitter and the sensors, obstacles in front of the blind can be detected by using time-of-flight of the ultrasonic wave. Because of amplitude recession, temperature, and humidity can influence the measurement accuracy, deviation analysis becomes very important for the ultrasonic positioning system. A cone with angle of ±15°, 1 meter to 2 meters in front of the sensors has been evaluated as a test region for the system. Some simulation results and conclusions are also given in this paper.

並列關鍵字

ultrasonic ； position measurement ； deviation analysis