title: A multi-frequency method for ultrasonic ranging.
abstract: This paper presents a method for ultrasonic ranging based on the cross-correlation of two multi-frequency signals. The stimulus signal is composed by multiple sine-wave bursts/segments, each containing a different frequency and an integer number of periods. The frequency of each sine-wave burst is different from that of the adjacent bursts, but it is very close to the transducer resonant frequency. The time-of-flight (TOF) is estimated by finding the maximum of the cross-correlation. Interpolation is used to increase the measurement resolution. The experimental error corresponding to two standard deviations, for a range up to 1 m, is less than 0.3 mm.
authors.affiliation: Instituto de Telecomunicações/Instituto Superior Técnico, University of Lisbon, Portugal. Electronic address: ricardo.queiros@ieee.org.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Queirós
authors.affiliation: Instituto de Telecomunicações/Instituto Superior Técnico, University of Lisbon, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Corrêa Alegria
authors.affiliation: Instituto de Telecomunicações/Instituto Superior Técnico, University of Lisbon, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Silva Girão
authors.affiliation: Instituto de Telecomunicações/Instituto Superior Técnico, University of Lisbon, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Cruz Serra
keywords: Cross-correlation; Time-of-flight; Ultrasonic distance measurement