Implementation of An Ultrasonic Distance Measurement System Based on A Binary Amplitude-Shift-Keyed(BASK) Modulation Technique

• Main Authors: Yau-Cheng Tsai, 蔡燿丞
• Other Authors: M.S. Young
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/41531916228018486940

碩士 === 國立成功大學 === 電機工程學系碩博士班 === 91 === A high accurate Binary Amplitude-Shift-Keyed (BASK) modulated ultrasonic distance measurement system for use in isothermal air is developed. In this paper, we present a simple but efficient algorithm based upon phase shifts generated by three ultrasonic waves with different frequencies. By the proposed method, we can conduct longer distance measurement than the phase-shift method and get higher accuracy results compared with the time-of-flight (TOF) method. Our microcontroller-based system includes two important parts. One is BASK modulation signal generator and the other is a phase meter by which phase shifts of the three different frequency signals are obtained. Data is sent to PC via RS232 serial ports and then recorded and analyzed with LabVIEW. The main advantages of this distance measurement system are high accuracy in long distance measurement, low cost and easily implemented with cheap and common ultrasound transducers.