US-20260126334-A1 - METHOD AND PORTABLE DEVICE FOR DETECTING LEAKS IN A PIPE

Abstract

A method for electro-acoustic detection of a leak in a pipe conveying a fluid, implemented by a portable device and includes: a step of acquiring a sound signal emitted by the pipe by means of a microphone; a step of processing the signal in real-time with a frequency analysis of the signal by means of a periodogram and extracting features of the signal, including the entropy, a damage-sensitive feature referred to as DSF and a centered frequency corresponding to the barycenter of the periodogram; a step of applying a Kalman filter to estimate residuals; a step of principal component analysis allowing modeling a normal signal of the pipe and of detecting any leak by comparing the signal observed in the normal signal; and an alert and/or notification step in case of detection of a leak.

Inventors

• FABRICE GAUTIER

Assignees

• ALCOM TECHNOLOGIES

Dates

Publication Date

20260507

Application Date

20241107

Claims (8)

1. 1 . A method for electro-acoustic detection of a leak in a pipe conveying a fluid, comprising: a step of acquiring a sound signal emitted by the pipe by means of a microphone; and a step of processing the signal in real-time; characterized in that the signal processing step comprises: a step of frequency analysis of the signal by means of a periodogram allowing estimating the power spectral density of said signal; and a step of extracting features of the signal, including the entropy, a damage-sensitive feature referred to as DSF and a centered frequency corresponding to the barycenter of the periodogram; and in that it comprises, after the steps hereinabove: a step of applying a Kalman filter to estimate residuals corresponding to leak-revealing signals, these residuals being acoustic signatures revealing the presence of a leak in the pipe; a principal component analysis step allowing modeling a normal signal of the pipe and detecting any leak by comparing the observed signal with the normal signal; and a step of presenting the results and alerting and/or notifying in case of detection of a leak; and in that it is entirely implemented by a portable device comprising the microphone
2. 2 . The method according to claim 1 , wherein the entropy of the signal is computed with an approximate entropy model.
3. 3 . The method according to claim 1 , wherein the feature DSF is computed from an autoregressive model of the signal.
4. 4 . The method according to claim 3 , wherein the autoregressive model of the signal is an integrated moving-average model having so-called ARIMA coefficients, and the feature DSF is equal to the ratio between the first ARIMA coefficient and the square root of the sum of the squares of the first three ARIMA coefficients.
5. 5 . The method according to claim 1 , wherein the step of principal component analysis of the signal implements artificial intelligence algorithms to improve leak detection by assigning a weight to each feature computed in the feature extraction step.
6. 6 . The method according to claim 4 , wherein: the step of principal component analysis of the signal implements artificial intelligence algorithms to improve leak detection by assigning a weight to each feature computed in the feature extraction step; and the weights and the coefficients used in the computations are optimized by a genetic algorithm for each implementation after a training period.
7. 7 . A portable device comprising a microphone and computing means in the form of a microprocessor, for implementing a method for detecting leaks in a pipe according to claim 1 .
8. 8 . The portable device according to claim 7 , comprising a smartphone-type mobile terminal connected to the microphone the method being executed in a dedicated mobile application.

Description

BACKGROUND Field The present disclosure relates to the field of devices for processing signals, in particular acoustic signals emitted upon a fluid-structure interaction, and relates, more particularly, to a method for detecting a leak in a pipe conveying any fluid and to a portable device for implementing such a method. The present disclosure finds a direct, yet non-exclusive, application in the detection of leaks in a drinking water network. Brief Description of Related Developments Pipes, especially those intended for supplying under pressure such as water pipes in a drinking water network or industrial fluid pipes in factories, are subject to various defects that might lead to the apparition of leaks. These leaks compromise the normal operation of the pipes and may have serious consequences both in technical terms and in economic and environmental terms. The detection of these leaks often proves to be an arduous task, in particular because of the difficulty of access to the pipes, sometimes buried, and of the size of these. Some “artisanal” solutions are based on the human analysis of the sound emitted by a pipe and recorded with a microphone or probed with a stethoscope. These solutions are tedious, barely accurate and require the intervention of technicians having a great expertise. Document U.S. Pat. No. 4,309,576 describes a listening device for locating water leaks, comprising a manually-actuated rod having a grip at one end for manually positioning the listening device. An acoustic sensing apparatus is mounted at the other end of the rod, and it comprises an audio tone transducer made of ceramic which is operatively connected to an amplifier-receiver which has a level indicator on which visual leak signals could be seen. The acoustic sensing apparatus is also connected to a headset to allow hearing the leaks. The transducer comprises a diaphragm made of brass directly fastened to a threaded pin for mounting in the rod. There are solutions so-called invasive because they require the introduction of an object into the pipe to carry out the leak detection. For example, methods are known using a photonic detection technology which transforms an optical fiber cable running along a network of water pipes into thousands of vibration sensors, capable of detecting a disturbance over the entire length of the pipe. Document FR2935800 describes a method for detecting leaks in an underground liquid pipe, in particular a water pipe, according to which: a gas is injected through a diffuser into the liquid of the pipe, the content of which gas in the atmosphere is low, and the pathway of the pipe is covered at the surface with a detection system to measure, at successive points, the injected gas content in the air, an abnormally high content being a leak indication. This solution is obviously extremely expensive and very impractical. Document EP2710291 describes a system for identifying leaks in the construction of hoses for liquids, composed of at least one detection unit positioned proximate to at least one outlet point of said hose construction and comprising an acoustic sensor and a wireless communication unit, of an electronically-controlled closure unit installed on an inlet point of the hose construction, the unit comprising a valve, an acoustic sensor and a wireless communication unit arranged so as to transmit water flow rate data and to receive control signals, and of a controller network device for receiving the measurement data from all sensors. The controller is programmed to detect leaks when it identifies differences between the liquid flow rate measured at the inlet point and the flow rate measured at the outlet points. Document WO2004/063623 describes a method and a device allowing detecting possible leaks in a pipeline. The pipeline is continuously monitored by acoustic monitoring means, and the acoustic events indicating a possible leak are recorded. The pipeline is also equipped with means for continuous monitoring of the temperature, periodically or on demand. According to this solution, it is estimated that a leak is likely when an acoustic event indicates a possible leak at one location and if, approximately at the same time, a temperature difference higher than a predetermined value is detected between this location and the adjacent locations. In this solution, the temperature may be monitored by a satellite, an aircraft or a drone. Document EP2028471 describes a leak detector enabling an accurate and stable detection of the presence and of the position of a leak in an underground water pipe. The leak detector includes a vibration detector having a sensor incorporating a piezoelectric element, a main body of the detector incorporating voltage amplifiers for amplifying the voltage of an output signal and several types of noise suppression units for suppressing noises from the output signal and an earphone. The main body of the detector has a display unit for displaying detected sound data o