Real time leak detection and isolation in pipelines: a comparison between Sliding Mode Observer and algebraic steady state method

The purpose of this paper is to compare two different algorithms used to detect and isolate water leaks in a pipeline. One method is based on a Sliding Mode Observer and the second method is an Algebraic method obtained from the pipeline model in steady state. Because of the simplicity of both methods, they can be easily implemented. The methods were tested offline with real time data and the Algebraic method was also implemented online. Satisfactory results are shown through some experiments.Consejo Nacional de Ciencia y Tecnologí

Real Time Leak Isolation in Pipelines Based on a Time Delay Neural Network

In this paper, the one leak isolation problem in a water pipeline is tackled using a Time Delay Neural Network. This scheme comes as an alternative to achieve better computing performance since the classical model-based methods usually have high workloads due to the pipe mathematical model complexity compared with the leak dynamics speed. The Neural Network structure could have better time performance exploiting the parallel architecture of some electronics devices like an FPGA. The authors propose a scheme where, due to the difficulty in obtaining training data from a real pipeline, a mathematical model is used to generate synthetic training data. Such training data is obtained using different leak magnitudes and leak positions and it is also corrupted by random noise in order to emulate real data pipe. Finally, to show the potentiality of this method, some results are presented by using real-noisy databases coming from a pipeline prototype.Following the classical leak diagnosis hypothesis, only flow and pressure sensor at both ends of the aqueducts are used for the treatment.ITESO, A.C

An algebraic observer for leak detection and isolation in plastic pipelines

In the continuation of authors' studies on leak diagnosis in pipelines, a new model-based Leak Detection and Isolation (LDI) algorithm is designed. This system only uses measures of flow and pressure coming from sensors placed at the ends of a pipeline. The present approach is based on a finite nonlinear pipeline model, and extended with variables related to the leak. On this basis, the purpose here is to investigate the use of a so-called algebraic observer to estimate the leak position and its magnitude. The corresponding observer design is thus presented, and its performances are illustrated both with simulation results, and experimental ones, with data taken from a real pipeline prototype.Consejo Nacional de Ciencia y TecnologíaInstitut Universitaire de FranceUniversidad Nacional de Colombi

Control óptimo aguas abajo de un canal de laboratorio

En este trabajo se presentan los resultados obtenidos al aplicar un regulador Óptimo Lineal Gaussiano en el control aguas abajo de un canal de laboratorio de dos tramos localizado en el laboratorio de la Escuela Superior de Ingenieros en Sistemas Industriales Avanzados de la región Rhone Alpes en Francia. Los resultados obtenidos ponen de manifiesto que es posible implementar el control aguas abajo en un canal mediante equipo electrónico. El regulador óptimo usado muestra satisfactorios resultados en el control del nivel aguas abajo al final de cada tramo

Colorado River Irrigation District

Presented at SCADA and related technologies for irrigation district modernization: a USCID water management conference on October 26-29, 2005 in Vancouver, Washington.Includes bibliographical references.The Colorado River Irrigation District is the last irrigation district and water user on the Colorado River. It obtains 80% of the allocated volume to the district from the Colorado River. The inflow to the district presents fluctuations. The first 27 km of the mail canal are used as buffer reservoir. Between 2002 and 2004 to improve water management, the National Water Commission, Mexican federal agency responsible of water reclamation, installed a remote monitoring system for the head control structures. The system was integrated around MODBUS as communication protocol, Lookout from National Instruments as man machine interface, SCADAPack from Control Microsystems as remote terminal units, "The Probe" from Milltronics as level sensors, Transpak potentiometer transmitters for gate opening and MDS 4710 and 4910 radios from Microwave Data Systems for communication. The remote monitoring system installed was complemented with the remote operation of one control structures. The system starts operation on February of 2005. The remote monitoring system reduces the time required to know, to quantify and to correct the flow and level fluctuations present on the head control structures

Two-leak isolation in water distribution networks based on k-NN and linear discriminant classifiers

In this paper, the two-simultaneous-leak isolation problem in water distribution networks is addressed. This methodology relies on optimal sensor placement together with a leak location strategy using two well-known classifiers: k-NN and discriminant analysis. First, zone segmentation of the water distribution network is proposed, aiming to reduce the computational cost that involves all possible combinations of two-leak scenarios. Each zone is composed of at least two consecutive nodes, which means that the number of zones is at most half the number of nodes. With this segmentation, the leak identification task is to locate the zones where the pair of leaks are occurring. To quantify the uncertainty degree, a relaxation node criterion is used. The simulation results evidenced that the outcomes are accurate in most cases by using one-relaxation-node and two-relaxation-node criteria.The APC was funded by Tecnológico de MonterreyPeer ReviewedPostprint (published version

Developpement et analyse d'outils pour la conception des systemes de commande robuste

Available from INIST (FR), Document Supply Service, under shelf-number : T 83290 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Calibration of Fitting Loss Coefficients for Modelling Purpose of a Plastic Pipeline

International audienceMotivated by the sensitivity of model-based monitor- ing algorithms to the so-called Equivalent Straight Length (ESL) of a pipeline, this paper proposes an experiment- based calibration of this parameter and also for the val- ues of the Fitting Loss Coefficients (FLC). This comes as an alternative to achieve a better description of the real flow behavior in a pipeline than the modelling obtained by using the FLC from the manufacturer data-sheet. The proposed calibration method relies on a flow mod- elling, and Kalman observer-based estimation of the FLC of a pipeline. The friction coefficient in the model is es- timated by the explicit so-called Swamee-Jain equation. The approach only assumes sensors of flow and pressure at the ends of the duct. Experimental results are presente

Online implementation of a leak isolation algorithm in a plastic pipeline prototype

International audienceIn this paper, a real-time applica- tion of a Leak Detection and Isolation (LDI) al- gorithm for a plastic pipeline is presented. This LDI algorithm is fed with flow and pressure sig- nals coming from sensors placed at the ends of the pipeline. It uses a flow observer based on a model obtained from the Method of Charac- teristics, and it is designed in order to assure an acceptable real-time leak isolation by taking into account various practical difficulties. In particular it incorporates an adaptation law for the friction coefficient in order to compensate for possible variations. The whole scheme is successfully tested on a plastic pipeline proto- type, transporting water and built as a possible benchmark

Leak Isolation Based on Extended Kalman Filter in a Plastic PipelineUnder Temperature Variations with Real-Data Validation

International audienceThe present work is motivated by the purpose of considering a more realistic scenario than in former studieson the problem of leak isolation within a plastic pipeline, when the water can be affected by temperature changes. In order to address this situation, a state observer approach based on a model including temperature effect and an Extended Kalman Filter is proposed. Noting indeed that temperature affects some equivalent straight length of the pipe, which is used in the model, the observer estimates it together with the leak coefficients. This approach only considers head pressure and flow rate measurements coming from pipeline ends, likewise, water temperature measurement at upstream tank. Results with real data obtained from a pipeline prototype are shown in two different ways in order to illustrate the performance of proposed leak isolation system, as compared to the traditional approaches found at literature