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Leak Localization in open water Channels. Workshop on irrigation channels and related problems. N.Bedjaoui, E.Weyer and G. Bastin. Nadia Bedjaoui. Outline. Problem statement Objective of this work Leak localization methods Application Conclusion. Outline. Problem statement
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Leak Localization in open water Channels Workshop on irrigation channels and related problems N.Bedjaoui, E.Weyer and G. Bastin Nadia Bedjaoui
Outline • Problem statement • Objective of this work • Leak localization methods • Application • Conclusion
Outline • Problem statement • Objective of this work • Leak localization methods • Application • Conclusion
Outline • Problem statement • Objective • Methods • Application Problem statement • Irrigation channel = supply water to users for irrigation purposes • Supply done with less water losses possible • Manual control large water losses • Automatic control minimizes these losses • Additional water losses due to the presence of leaks • Leak =wasted water left definitively from the channel
Outline • Problem statement • Objective • Methods • Application Problem statement Types of leaks in irrigation channels • Failures in the civil engineering:Affect the walls of the channel
Outline • Problem statement • Objective • Methods • Application Problem statement Types of leaks in irrigation channels • Failures in the civil engineering:Affect an escape gate
Outline • Problem statement • Objective • Methods • Application Problem statement Types of leaks in irrigation channels • Unpredicted offtakes Affect the farmer offtakes
Outline • Problem statement • Objective • Methods • Application Problem statement • Important to • Detect the presence of the leak • Estimate the size of the leak • Localize the position of the leak
Outline • Problem statement • Objective • Methods • Application Problem statement Leak Detection + Estimation(E. Weyer& G. Bastin 2008) • Based on mass-balance model • Idea :Do the measurements check the model? • CUSUM algorithm: quick detection+ no faulse alarm • Impossible leak localization
Outline • Problem statement • Objective of this work • Leak localization methods • Application • Conclusion
Outline • Problem statement • Objective • Methods • Application Objective of this work • Interest: leak localization • Leak is already detected and estimated by CUSUM algorithm (Weyer & Bastin 2008) • Investigatation of two methods • Model used: Saint Venant model as Hyperbolic Partial DifferentialEquations PDE • Method (1) bank of Nonlinear Saint-Venant models • Method (2) bank of Nonlinear Observers
Outline • Problem statement • Objective of this work • Leak localization methods • Method (1) using a bank of pure models • Modelling: Saint Venant is hyperbolic PDE • Method (2) using a bank on observers • Observer objective • Observer structure • Observer Design • Application • Conclusion
Outline • Problem statement • Objective • Methods (1) • Application • Conclusion Method (1): Modelling Q(t,0) Y(t,0) Y(t,L) Q(t,L) P0(t) Pool PL(t) Upstream Gate w xl Leak Downstream Gate L x x=0 x=L
Outline • Problem statement • Objective • Methods (1) • Application • Conclusion Method (1): Modelling • Saint Venant Equations • Boundary conditions (x=0 & x=L)(=Gate equations) • Overshot gate • Offtake
Outline • Problem statement • Objective • Methods (1) • Application • Conclusion Method (1):Modelling Two coupled quasi-linearHyperbolic PDE • subcritical flow
Outline • Problem statement • Objective • Methods (1) • Application • Conclusion Method (1):Modelling • Initial Conditions (in t=0) • Boundary Conditions (in x=0 & x=L)
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer Method (2): using a bank of Observers Objective of the observer: • From any Initial Conditions (t=0) • Using the only measurements Y(t,0) & Y(t,L) • The estimation error converges to zero
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer Method (2): using a bank of Observers • Observer structure • Boundary conditions
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer Method (2): using a bank of Observers • Observer design 1) Linearized model 2) Formulating the estimation problem as a control problem 3) Using the results on boundary control to determine the boundary conditions of the observer that achieves good estimation
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer • Observer design 1) Linearized model around an equilibrium -Deviations from the equilibrium -Linearized model
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer • Observer design 1) Linearized observer around an equilibrium -Deviations from the equilibrium -Linearized observer Estimation error
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer 2) Formulating the estimation problem as a control problem -Control objective: regulate the deviations to 0 using boundary inputs -Estimation problem: regulate the estimation error to 0 using the boundary output errors
Summary on boundary control of Saint Venant equations -Linear case + non-homogenous terms -Linear case +non-homogenous terms [ Bastin et al 2008] small enough for Saint Venant Subcritical flow -Quasi-linear case +non-homogenous terms [ Prieur et al 2008] small enough & sufficiently small
Outline • Problem statement • Objective • Methods (2) • Application • Conclusion Method (2):Observer Method (2): using a bank of Observers • Initial Conditions (t=0) • Boundary Conditions (x=0 & x=L)
Localization scheme • Method 1 • Method 2
Outline • Introduction • Problem statement • Objective of this work • Leak localization methods • Method based on models • Method based on observers • Application of the 2 methods • Description of the system of application • Results and observations with • Simulated data • Real data • Conclusion
Application of the 2 methods • Description of the system of application Farm Farm Gate 1 Gate 2 Gate 3 Gate 4 Gate 5 Gate 6 Topview of Coly 6 L=943m, delay=5mn, Silde slope=2 Bottom width=1.80m Gate width=1.91m
Scenario yx0 qx0 yxL qxL px0 Pool 5 pxL Gate 4 dxL Gate 5 Offtake Section=35
Application on simulated data • Scenario yx0 qx0 yxL qxL px0 Pool 5 pxL Gate 4 dxL Gate 5 Offtake Section=35
Outline • Introduction • Problem statement • Objective of this work • Leak localization methods • Method based on models • Method based on observers • Application of the 2 methods • Description of the system of application • Results and observations with • Simulated data • Real data • Conclusion
Application on real data • Scenario yx0 qx0 yxL qxL px0 Pool 5 pxL Gate 4 dxL Gate 5 Offtake
Outline • Introduction • Problem statement • Objective of this work • Leak localization methods • Method based on models • Method based on observers • Application of the 2 methods • Description of the system of application • Results and observations with • Simulated data • Real data • Conclusion
Localization scheme • Method 1 • Method 2
Conclusion • Objective: Leak localization • Investigate two methods for leak localization • Method (1) based on pure models • Method (2) based on observers • Design of observer: - Characteristic method • The estimation problem is written as boundary control problem for the linearized system • Convergence of the observer can be fixed by the gains
Conclusion (2/2) • Both methods give similar results • Leak localization is too sensitive: • Model uncertainty • Offset on measurments • Time Starting detection • Feedback control
Conclusion (2/2) 2) Réconciliation de données globale Appliquée à un bief avec retards discrétisés : Filtre de Kalman détection de prélèvements+défauts Combinaison locale -globale Distinction défaut -prélèvement 3) Observateurs à entrées inconnues et H Cas général des systèmes à retards • Retards dans l’état et les entrées • Retards variants dans le temps • Méthode testée avec succès sur le canal de Gignac