An ultrasonic array sensor for spacecraft leak direction finding

Abstract

We have developed an ultrasonic array sensor useable for locating air leaks in manned spacecraft and have found that this sensor locates leaks in a 1-m 2 plate to within 2 cm. The sensor consists of a 63-element multiplexed array plus a reference element, all constructed from a single PZT disc and a printed circuit board. Cross-correlations of signals from the array elements with signals from the single reference element provide a measurement of the leak noise passing through the spacecraft skin under the array. A spatial Fourier transform reveals the dominant direction of propagation. Triangulation from multiple sensor locations can be used to find the source of the leak. We have developed an ultrasonic array sensor useable for locating air leaks in manned spacecraft and have found that this sensor locates leaks in a 1-m 2 plate to within 2 cm. The sensor consists of a 63-element multiplexed array plus a reference element, all constructed from a single PZT disc and a printed circuit board. Cross-correlations of signals from the array elements with signals from the single reference element provide a measurement of the leak noise passing through the spacecraft skin under the array. A spatial Fourier transform reveals the dominant direction of propagation. Triangulation from multiple sensor locations can be used to find the source of the leak.

Research on Leakage Location of Spacecraft in Orbit Based on Frequency Weighting Matrix Beamforming Algorithm by Lamb Waves

“…For a collision with a time point of occurrence, location can be performed by calculating the time difference of arrival. To solve the above problems, Holland et al [9,10] carried out research on cross-correlation and two-dimensional Fourier transform techniques to determine air leakages on the International Space Station (ISS). In the study, two 16 × 16 sensor arrays were applied to locate a leak.…”

Localization of a continuous CO2leak from an isotropic flat-surface structure using acoustic emission detection and near-field beamforming techniques

“…Cui et al investigated an empirical mode decomposition (EMD) and cross correlation method to improve the accuracy of localization [12]. Holland et al developed an ultrasonic array sensor and a spatio-temporal Fourier transform technique based f-k analysis of cross correlations to find the leak direction in a manned spacecraft [13][14][15]. It is worth noting that two or more peak points with similar amplitude may appear and lead to a large localization error when calculating TDOA using the cross-correlation technique in some cases.…”

A New Method of Using Sensor Arrays for Gas Leakage Location Based on Correlation of the Time-Space Domain of Continuous Ultrasound

“…However, this method is easily affected by the structure of the detected object and background noise, so it has a large location error under normal circumstances. Holland et al proposed an 8 × 8 sensor array to collect ultrasonic signals of orbiting spacecraft leaks [ 20 , 21 , 22 , 23 ], and calculated the intensity distribution of the wave number diagram (k-domain) of the collected signal, to estimate the direction of the sound source. Meanwhile, two sets of array orientation results are used to locate the leakage.…”

“…A large amount of experimental results indicate that this algorithm can stably locate leakage sources in real-time. Compared with the previous location method [ 20 , 21 , 22 ], it can achieve higher location accuracy with a smaller number of sensors in one array, and has better real-time detection properties.…”