ISSN: 0090-3973
Page Count: 8

Ultrasonic Signal-Transmission Techniques for Compact Microtunneling Systems

Honjoh, K
Senior engineer,Technical Assistance & Support Center, Nippon Telegraph and Telephone Corp. (NTT),

Hoshiya, K
Senior research engineer,Integrated Information & Energy Systems Labs., NTT,

Nakano, S
research engineer,Integrated Information & Energy Systems Labs., NTT,

Kuwano, H
Senior manager,NTT,

Abstract

This paper describes ultrasonic transmission techniques for sensor signals transmitted through water-filled pilot pipes for underground microtunneling systems. Underwater ultrasonic waves are used for transmitting the orientation and location signals of a remote-controlled machine. We have investigated the relationship between ultrasonic transmission loss and frequency with propagation distance in water-filled pipes. Digital signals can be transmitted at 100 bps for more than 50 m in 80-mm-diameter steel pipes by using underwater ultrasonic pulse waves above 300 kHz. A compact prototype ultrasonic transmitter and receiver were developed, making it possible to transmit and receive 8-bit signals through flowing water in the pilot pipes by processing their signal waveforms. Field trials demonstrated a range of signal transmission of pitching angle data over a 40-m distance for an actual compact microtunneling system.

Keywords:
ultrasonic attenuation, soil particles, air bubbles, frequency, flow rate, pulse signal, pilot pipe, micro-tunneling

Paper ID: JTE12049J
DOI: 10.1520/JTE12049J
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