DocumentCode :
1212580
Title :
Design of digital polarity correlators in a multiple-user sonar ranging system
Author :
Nakahira, Kenji ; Kodama, Tetsuji ; Furuhashi, Takeshi ; Maeda, Hiroshi
Author_Institution :
Dept. of Electr. Eng., Nagoya Univ., Japan
Volume :
54
Issue :
1
fYear :
2005
Firstpage :
305
Lastpage :
310
Abstract :
Pulsed ultrasonic distance measurement systems are frequently used in robotics applications thanks to their low cost and small size. The pulse compression techniques, originally developed by radar engineers, were adopted to eliminate frequent misreadings caused by crosstalk or external ultrasound sources. However, a few problems become apparent when implementing the pulse compression techniques in robotics applications. First, due to the implementation of correlation functions, the complexity of the total system may significantly increase. Second, if the piezoelectric transducer is excited by a chirp signal, efficiency is reduced due to the narrow bandwidth. In this paper, we present a digital polarity correlator designed for binary coded frequency shift keyed signals which increase the number of different sequences having the same length in a restricted band. The digital signal processing system is integrated into a single programmable logic device. Experimental measurements have been made, and a good agreement with reference data has been obtained with noise added.
Keywords :
binary codes; correlators; digital signal processing chips; distance measurement; frequency shift keying; mobile robots; modulation coding; programmable logic devices; pulse compression; sonar signal processing; binary coded frequency shift keyed signals; binary sequences; chirp signal; correlation functions; digital polarity correlators; digital signal processing system; external ultrasound sources; multiple-user sonar ranging system; piezoelectric transducer; programmable logic device; pulse compression techniques; pulsed ultrasonic distance measurement systems; radar engineers; robotics applications; sonar sensing; Correlators; Costs; Crosstalk; Distance measurement; Pulse compression methods; Pulse measurements; Radar; Robots; Sonar measurements; Ultrasonic imaging;
fLanguage :
English
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9456
Type :
jour
DOI :
10.1109/TIM.2004.839753
Filename :
1381831
Link To Document :
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