Wavelet-based Burst Event Detection and Localization in Water Distribution Systems

In this paper we present techniques for detecting and locating transient pipe burst events in water distribution systems. The proposed method uses multiscale wavelet analysis of high rate pressure data recorded to detect transient events. Both wavelet coefficients and Lipschitz exponents provide additional information about the nature of the signal feature detected and can be used for feature classification. A local search method is proposed to estimate accurately the arrival time of the pressure transient associated with a pipe burst event. We also propose a graph-based localization algorithm which uses the arrival times of the pressure transient at different measurement points within the water distribution system to determine the actual location (or source) of the pipe burst. The detection and localization performance of these algorithms is validated through leak-off experiments performed on the WaterWiSe@SG wireless sensor network test bed, deployed on the drinking water distribution system in Singapore. Based on these experiments, the average localization error is 37.5 m. We also present a systematic analysis of the sources of localization error and show that even with significant errors in wave speed estimation and time synchronization the localization error is around 56 m.Singapore-MIT Alliance for Research and Technolog

Burst Detection and Localization using Discrete Wavelet Transform and Cross-Correlation

[ES] La ruptura súbita en los sistemas de distribución de agua provoca gran pérdida de este recurso natural, interrumpe el abastecimiento, daña las calles y edificaciones y aumenta la transmisión de enfermedades infecciosas. En este artículo se propone un nuevo algoritmo que permite la detección y localización automática de rupturas súbitas en los sistemas de distribución de agua. En cuanto a la detección, la novedad consiste en usar el criterio de correlación wavelet para computar la decisión estadística y compararla con un umbral de detección. La novedad en la localización consiste en usar el operador estadístico correlación cruzada. El algoritmo se implementó en Octave y fue validado con 32 señales adquiridas en el laboratorio en una tubería de acero de 26.7 m de longitud. En 16 señales se provocó ruptura súbita las cuales fueron detectadas bajo una probabilidad de falsos positivos de 2 %. No se presentaron falsos positivos en las 16 señales donde solamente estaba la presencia de ruido.[EN] Burst in water distribution systems causes great loss of this natural resource, interrupts the water supply, damages the streets, builds and increases the transmission of infectious diseases. In this paper we propose a new algorithm that allows the detection and automatic localization of burst in water distribution systems. As for detection, the novelty is to use the wavelet correlation criterion to compute the statistical decision and compare it with a detection threshold. The novelty in the localization is to use the statistical operator cross-correlation. The algorithm was implemented in Octave and was validated with 32 signals acquired in the laboratory in a 26.7 m long steel pipe. In 16 signals burst were triggered which were detected under a false positive probability of 2 %. No false positives were present on the 16 signals where only noise was present.Trutié-Carrero, E.; Valdés-Santiago, D.; León-Mecías, Á.; Ramírez-Beltrán, J. (2018). Detección y Localización de Ruptura Súbita mediante Transformada Wavelet Discreta y Correlación Cruzada. Revista Iberoamericana de Automática e Informática industrial. 15(2):211-216. https://doi.org/10.4995/riai.2017.8738OJS211216152Cedeño, A., Trujillo, R., 2013. Estudio comparativo de técnicas de reducción de ruido en se-ales industriales mediante transformada wavelet discreta y selección adaptativa del umbral. Revista Iberoamericana de Automática e Informática Industrial RIAI 10, 143-148. https://doi.org/10.1016/j.riai.2013.03.003Donoho, D. L., Johnstone, J. M., 1994. Ideal spatial adaptation by wavelet shrinkage. Biometrika 81, 425-455. https://doi.org/10.1093/biomet/81.3.425Eaton, J. W., Bateman, D., Hauberg, S., Wehbring, R., 2014. GNU Octave version 3.8.1 manual: a high-level interactive language for numerical computations. CreateSpace Independent Publishing Platform.Ebacher, G., Besner, M.-C., Prévost, M., Allard, D., 2010. Negative pressure events in water distribution systems: Public health risk assessment based on transient analysis outputs. In: Water Distribution Systems Analysis 2010. pp. 471-483.Grinstead, C. M., Snell, J. L., 1997. Introduction to Probability. American Mathematical Society.Luo, Jun; Liu, G. H. Z., 2016. Damage detection for shear structures based on wavelet spectral transmissibility matrices under nonstationary stochastic excitation. Structural Control and Health Monitoring. https://doi.org/10.1002/stc.1862Mallat, S., 1999. A Wavelet Tour of Signal Processing. Academic Press. Martini, A., Troncossi, M., Rivola, A., 2013. Vibration monitoring as a tool for leak detection in water distribution networks. In: International Conference Surveillance 7.Meniconi, S., Brunone, B., Ferrante, M., Capponi, C., Pedroni, M., Zaghini, M., Leoni, F., 2014. Transmission Main Survey by Transient Tests: The Case of Villanova Plan in Mantova (I). Procedia Engineering 89. https://doi.org/10.1016/j.proeng.2014.11.454Mounce, Stephen R.; Mounce, R. B. B. J. B., 03 2012. Identifying sampling interval for event detection in water distribution networks. Journal of Water Resources Planning and Management 138. https://doi.org/10.1061/(ASCE)WR.1943-5452.0000170Oppenheim, A. V., Schafer, R. W., 2010. Discrete-Time Signal Processing. Prentice Hall.Proakis, J. G., Manolakis, D. G., 2006. Digital signal processing: principles, algorithms, and applications. Prentice-Hall.Rathnayaka, S., Shannon, B., Rajeev, P., Kodikara, J., 2016. Monitoring of pressure transients in water supply networks. Water Resources Management 30 (2), 471-485. https://doi.org/10.1007/s11269-015-1172-ySrirangarajan, S., Allen, M., Preis, A., 2013. Wavelet-based burst event detection and localization in water distribution systems. Journal of Signal Processing Systems 72, 1-16. https://doi.org/10.1007/s11265-012-0690-6Srirangarajan, S., Iqbal, M., Lim, H. B., Allen, M., Preis, A., Whittle, A. J., 2011. Water main burst event detection and localization. In: Water Distribution Systems Analysis 2010. Tucson, Arizona, United States. https://doi.org/10.1061/41203(425)119Ye, G., Fenner, R. A., 2011. Kalman filtering of hydraulic measurements for burst detection in water distribution systems. Journal of Pipeline Systems Engineering and Practice 2, 14-22. https://doi.org/10.1061/(ASCE)PS.1949-1204.0000070Ye, G., Fenner, R. A., 2014. Study of burst alarming and data sampling frequency in water distribution networks. Journal ofWater Resources Planning and Management 140, 06014001-1-06014001-7. https://doi.org/10.1061/(ASCE)WR.1943-5452.0000394Zadkarami, M., Shahbazian, M., Salahshoor, K., 2017. Pipeline leak diagnosis based on wavelet and statistical features using dempster-shafer classifier fusion technique. Process Safety and Environmental Protection 105, 156-163. https://doi.org/10.1016/j.psep.2016.11.002Zan, T. T. T., Wong, K.-J., Lim, H. B., Whittle, A., 2011. A frequency domain burst detection technique for water distribution systems. In: 2011 IEEE Sensors Proceedings. pp. 1870-1873. https://doi.org/10.1109/ICSENS.2011.612732

Sensor Networks for Monitoring and Control of Water Distribution Systems

Water distribution systems present a significant challenge for structural monitoring. They comprise a complex network of pipelines buried underground that are relatively inaccessible. Maintaining the integrity of these networks is vital for providing clean drinking water to the general public. There is a need for in-situ, on-line monitoring of water distribution systems in order to facilitate efficient management and operation. In particular, it is important to detect and localize pipe failures soon after they occur, and pre-emptively identify ‘hotspots’, or areas of the distribution network that are more likely to be susceptible to structural failure. These capabilities are vital for reducing the time taken to identify and repair failures and hence, mitigating impacts on water supply. WaterWiSe is a platform that manages and analyses data from a network of intelligent wireless sensor nodes, continuously monitoring hydraulic, acoustic and water quality parameters. WaterWiSe supports many applications including dynamic prediction of water demand and hydraulic state, online detection of events such as pipe bursts, and data mining for identification of longer-term trends. This paper describes the WaterWiSe@SG project in Singapore, focusing on the use of WaterWiSe as a tool for monitoring, detecting and predicting abnormal events that may be indicative of structural pipe failures, such as bursts or leaks.Singapore-MIT Alliance for Research and Technology. Center for Environmental Sensing and Modelin

Pattern Recognition and Clustering of Transient Pressure Signals for Burst Location

[EN] A large volume of the water produced for public supply is lost in the systems between sources and consumers. An important-in many cases the greatest-fraction of these losses are physical losses, mainly related to leaks and bursts in pipes and in consumer connections. Fast detection and location of bursts plays an important role in the design of operation strategies for water loss control, since this helps reduce the volume lost from the instant the event occurs until its effective repair (run time). The transient pressure signals caused by bursts contain important information about their location and magnitude, and stamp on any of these events a specific "hydraulic signature". The present work proposes and evaluates three methods to disaggregate transient signals, which are used afterwards to train artificial neural networks (ANNs) to identify burst locations and calculate the leaked flow. In addition, a clustering process is also used to group similar signals, and then train specific ANNs for each group, thus improving both the computational efficiency and the location accuracy. The proposed methods are applied to two real distribution networks, and the results show good accuracy in burst location and characterization.Manzi, D.; Brentan, BM.; Meirelles, G.; Izquierdo Sebastián, J.; Luvizotto Jr., E. (2019). Pattern Recognition and Clustering of Transient Pressure Signals for Burst Location. Water. 11(11):1-13. https://doi.org/10.3390/w11112279S1131111Creaco, E., & Walski, T. (2017). Economic Analysis of Pressure Control for Leakage and Pipe Burst Reduction. Journal of Water Resources Planning and Management, 143(12), 04017074. doi:10.1061/(asce)wr.1943-5452.0000846Campisano, A., Creaco, E., & Modica, C. (2010). RTC of Valves for Leakage Reduction in Water Supply Networks. Journal of Water Resources Planning and Management, 136(1), 138-141. doi:10.1061/(asce)0733-9496(2010)136:1(138)Campisano, A., Modica, C., Reitano, S., Ugarelli, R., & Bagherian, S. (2016). Field-Oriented Methodology for Real-Time Pressure Control to Reduce Leakage in Water Distribution Networks. Journal of Water Resources Planning and Management, 142(12), 04016057. doi:10.1061/(asce)wr.1943-5452.0000697Vítkovský, J. P., Simpson, A. R., & Lambert, M. F. (2000). Leak Detection and Calibration Using Transients and Genetic Algorithms. Journal of Water Resources Planning and Management, 126(4), 262-265. doi:10.1061/(asce)0733-9496(2000)126:4(262)Pérez, R., Puig, V., Pascual, J., Quevedo, J., Landeros, E., & Peralta, A. (2011). Methodology for leakage isolation using pressure sensitivity analysis in water distribution networks. Control Engineering Practice, 19(10), 1157-1167. doi:10.1016/j.conengprac.2011.06.004Jung, D., & Kim, J. (2017). Robust Meter Network for Water Distribution Pipe Burst Detection. Water, 9(11), 820. doi:10.3390/w9110820Colombo, A. F., Lee, P., & Karney, B. W. (2009). A selective literature review of transient-based leak detection methods. Journal of Hydro-environment Research, 2(4), 212-227. doi:10.1016/j.jher.2009.02.003Choi, D., Kim, S.-W., Choi, M.-A., & Geem, Z. (2016). Adaptive Kalman Filter Based on Adjustable Sampling Interval in Burst Detection for Water Distribution System. Water, 8(4), 142. doi:10.3390/w8040142Christodoulou, S. E., Kourti, E., & Agathokleous, A. (2016). Waterloss Detection in Water Distribution Networks using Wavelet Change-Point Detection. Water Resources Management, 31(3), 979-994. doi:10.1007/s11269-016-1558-5Guo, X., Yang, K., & Guo, Y. (2012). Leak detection in pipelines by exclusively frequency domain method. Science China Technological Sciences, 55(3), 743-752. doi:10.1007/s11431-011-4707-3Holloway, M. B., & Hanif Chaudhry, M. (1985). Stability and accuracy of waterhammer analysis. Advances in Water Resources, 8(3), 121-128. doi:10.1016/0309-1708(85)90052-1Sanz, G., Pérez, R., Kapelan, Z., & Savic, D. (2016). Leak Detection and Localization through Demand Components Calibration. Journal of Water Resources Planning and Management, 142(2), 04015057. doi:10.1061/(asce)wr.1943-5452.0000592Zhang, Q., Wu, Z. Y., Zhao, M., Qi, J., Huang, Y., & Zhao, H. (2016). Leakage Zone Identification in Large-Scale Water Distribution Systems Using Multiclass Support Vector Machines. Journal of Water Resources Planning and Management, 142(11), 04016042. doi:10.1061/(asce)wr.1943-5452.0000661Mounce, S. R., & Machell, J. (2006). Burst detection using hydraulic data from water distribution systems with artificial neural networks. Urban Water Journal, 3(1), 21-31. doi:10.1080/15730620600578538Covas, D., Ramos, H., & de Almeida, A. B. (2005). Standing Wave Difference Method for Leak Detection in Pipeline Systems. Journal of Hydraulic Engineering, 131(12), 1106-1116. doi:10.1061/(asce)0733-9429(2005)131:12(1106)Liggett, J. A., & Chen, L. (1994). Inverse Transient Analysis in Pipe Networks. Journal of Hydraulic Engineering, 120(8), 934-955. doi:10.1061/(asce)0733-9429(1994)120:8(934)Caputo, A. C., & Pelagagge, P. M. (2002). An inverse approach for piping networks monitoring. Journal of Loss Prevention in the Process Industries, 15(6), 497-505. doi:10.1016/s0950-4230(02)00036-0Van Zyl, J. E. (2014). Theoretical Modeling of Pressure and Leakage in Water Distribution Systems. Procedia Engineering, 89, 273-277. doi:10.1016/j.proeng.2014.11.187Izquierdo, J., & Iglesias, P. . (2004). Mathematical modelling of hydraulic transients in complex systems. Mathematical and Computer Modelling, 39(4-5), 529-540. doi:10.1016/s0895-7177(04)90524-9Lin, J., Keogh, E., Wei, L., & Lonardi, S. (2007). Experiencing SAX: a novel symbolic representation of time series. Data Mining and Knowledge Discovery, 15(2), 107-144. doi:10.1007/s10618-007-0064-zNavarrete-López, C., Herrera, M., Brentan, B., Luvizotto, E., & Izquierdo, J. (2019). Enhanced Water Demand Analysis via Symbolic Approximation within an Epidemiology-Based Forecasting Framework. Water, 11(2), 246. doi:10.3390/w11020246Meirelles, G., Manzi, D., Brentan, B., Goulart, T., & Luvizotto, E. (2017). Calibration Model for Water Distribution Network Using Pressures Estimated by Artificial Neural Networks. Water Resources Management, 31(13), 4339-4351. doi:10.1007/s11269-017-1750-2Adamowski, J., & Chan, H. F. (2011). A wavelet neural network conjunction model for groundwater level forecasting. Journal of Hydrology, 407(1-4), 28-40. doi:10.1016/j.jhydrol.2011.06.013Brentan, B., Meirelles, G., Luvizotto, E., & Izquierdo, J. (2018). Hybrid SOM+ k -Means clustering to improve planning, operation and management in water distribution systems. 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Pattern recognition and clustering of transient pressure signals for burst location

A large volume of the water produced for public supply is lost in the systems between sources and consumers. An important-in many cases the greatest-fraction of these losses are physical losses, mainly related to leaks and bursts in pipes and in consumer connections. Fast detection and location of bursts plays an important role in the design of operation strategies for water loss control, since this helps reduce the volume lost from the instant the event occurs until its effective repair (run time). The transient pressure signals caused by bursts contain important information about their location and magnitude, and stamp on any of these events a specific "hydraulic signature". The present work proposes and evaluates three methods to disaggregate transient signals, which are used afterwards to train artificial neural networks (ANNs) to identify burst locations and calculate the leaked flow. In addition, a clustering process is also used to group similar signals, and then train specific ANNs for each group, thus improving both the computational efficiency and the location accuracy. The proposed methods are applied to two real distribution networks, and the results show good accuracy in burst location and characterization111

A novel pipeline leak detection technique based on acoustic emission features and two-sample Kolmogorov–Smirnov test.

Pipeline leakage remains a challenge in various industries. Acoustic emission (AE) technology has recently shown great potential for leak diagnosis. Many AE features, such as root mean square (RMS), peak value, standard deviation, mean value, and entropy, have been suggested to detect leaks. However, background noise in AE signals makes these features ineffective. The present paper proposes a pipeline leak detection technique based on acoustic emission event (AEE) features and a Kolmogorov–Smirnov (KS) test. The AEE features, namely, peak amplitude, energy, rise-time, decay time, and counts, are inherent properties of AE signals and therefore more suitable for recognizing leak attributes. Surprisingly, the AEE features have received negligible attention. According to the proposed technique, the AEE features are first extracted from the AE signals. For this purpose, a sliding window was used with an adaptive threshold so that the properties of both burst- and continuous-type emissions can be retained. The AEE features form distribution that change its shape when the pipeline condition changes from normal to leakage. The AEE feature distributions for leak and healthy conditions were discriminated using the two-sample KS test, and a pipeline leak indicator (PLI) was obtained. The experimental results demonstrate that the developed PLI accurately distinguishes the leak and no-leak conditions without any prior leak information and it performs better than the traditional features such as mean, variance, RMS, and kurtosis

Case study: a smart water grid in Singapore

As aging water distribution infrastructures encounter failures with increasing frequency, there is a real need for integrated, on-line decision-support systems based on continuous in-network monitoring of hydraulic and water quality parameters. Such systems will form the basis of a Smart Water Grid, allowing water utilities to improve optimization of system operation, manage leakage control more effectively, and reduce the duration and disruption of repairs and maintenance. WaterWiSe is an integrated, end-to-end platform for real-time monitoring of water distribution systems that addresses these needs. This paper describes how WaterWiSe's sensing and software platforms have helped improve the operational efficiency of the water supply system in downtown Singapore

Leakage Detection In Pipeline Using Wavelength

Nowadays natural gas transport and distribution is a complex and currently growing and increasing. Natural gas produced from well need to transport in a great distance before reaching it point of use. The pipeline is designed to quickly and efficiently transport the gas from its origin to the high demand area. Either pipelines transportation for water supply or natural gas, leakage is unacceptable problem. Small leak along the pipeline is hard to detect. The objective of this study is to build the test rig galvanized iron and MDPE pipelines. Besides that, the main objective is to determine the leak detection in gas pipeline using wavelet-based filtering. . Main point of each journal is compared in order to determine the problems arise from the previous research. It is then follow by the methodology which will discuss further in this chapter. From methodology, it is known that the data taken can be analysing through Daisy Lab and Math lab software  Wavelet and cross correlation is used to analyse the signal in Matlab. From the result, it show that the leak can be identified based on the peak of amplitude of the signal. The result for galvanized iron pipe is not acceptable due to short pipeline length. Thus it can be concluded that leak can be determined using wavelet-based filtering. As the conclusions, the propose technique can be used to determine the leak in pipeline

Methods and Systems for Fault Diagnosis in Nuclear Power Plants

This research mainly deals with fault diagnosis in nuclear power plants (NPP), based on a framework that integrates contributions from fault scope identification, optimal sensor placement, sensor validation, equipment condition monitoring, and diagnostic reasoning based on pattern analysis. The research has a particular focus on applications where data collected from the existing SCADA (supervisory, control, and data acquisition) system is not sufficient for the fault diagnosis system. Specifically, the following methods and systems are developed. A sensor placement model is developed to guide optimal placement of sensors in NPPs. The model includes 1) a method to extract a quantitative fault-sensor incidence matrix for a system; 2) a fault diagnosability criterion based on the degree of singularities of the incidence matrix; and 3) procedures to place additional sensors to meet the diagnosability criterion. Usefulness of the proposed method is demonstrated on a nuclear power plant process control test facility (NPCTF). Experimental results show that three pairs of undiagnosable faults can be effectively distinguished with three additional sensors selected by the proposed model. A wireless sensor network (WSN) is designed and a prototype is implemented on the NPCTF. WSN is an effective tool to collect data for fault diagnosis, especially for systems where additional measurements are needed. The WSN has distributed data processing and information fusion for fault diagnosis. Experimental results on the NPCTF show that the WSN system can be used to diagnose all six fault scenarios considered for the system. A fault diagnosis method based on semi-supervised pattern classification is developed which requires significantly fewer training data than is typically required in existing fault diagnosis models. It is a promising tool for applications in NPPs, where it is usually difficult to obtain training data under fault conditions for a conventional fault diagnosis model. The proposed method has successfully diagnosed nine types of faults physically simulated on the NPCTF. For equipment condition monitoring, a modified S-transform (MST) algorithm is developed by using shaping functions, particularly sigmoid functions, to modify the window width of the existing standard S-transform. The MST can achieve superior time-frequency resolution for applications that involves non-stationary multi-modal signals, where classical methods may fail. Effectiveness of the proposed algorithm is demonstrated using a vibration test system as well as applications to detect a collapsed pipe support in the NPCTF. The experimental results show that by observing changes in time-frequency characteristics of vibration signals, one can effectively detect faults occurred in components of an industrial system. To ensure that a fault diagnosis system does not suffer from erroneous data, a fault detection and isolation (FDI) method based on kernel principal component analysis (KPCA) is extended for sensor validations, where sensor faults are detected and isolated from the reconstruction errors of a KPCA model. The method is validated using measurement data from a physical NPP. The NPCTF is designed and constructed in this research for experimental validations of fault diagnosis methods and systems. Faults can be physically simulated on the NPCTF. In addition, the NPCTF is designed to support systems based on different instrumentation and control technologies such as WSN and distributed control systems. The NPCTF has been successfully utilized to validate the algorithms and WSN system developed in this research. In a real world application, it is seldom the case that one single fault diagnostic scheme can meet all the requirements of a fault diagnostic system in a nuclear power. In fact, the values and performance of the diagnosis system can potentially be enhanced if some of the methods developed in this thesis can be integrated into a suite of diagnostic tools. In such an integrated system, WSN nodes can be used to collect additional data deemed necessary by sensor placement models. These data can be integrated with those from existing SCADA systems for more comprehensive fault diagnosis. An online performance monitoring system monitors the conditions of the equipment and provides key information for the tasks of condition-based maintenance. When a fault is detected, the measured data are subsequently acquired and analyzed by pattern classification models to identify the nature of the fault. By analyzing the symptoms of the fault, root causes of the fault can eventually be identified