Model predictive control of resonance sensitive irrigation canals

Saving water is an economic and ecological need. One way to save water is to reduce losses in irrigation networks by canal automation. The goal of canal automation is to make the right amount of water to at arrive in the right time. In order to achieve this goal, one of the ways is controlling the gates in the irrigation network by some control algorithm. In this work the control of a specific type of canal pools is studied: short and flat pools that are prone to resonance. The downstream water level control of this type of canals is investigated using the example of the 3-reach laboratory canal of the Technical University of Catalonia. Numerical and experimental studies are carried out to investigate the following: the choice of models for predictive control, the possibility to achieve offset-free control while using gravity offtakes and the best choice of control action variables. The objective of this work is to develop a well performing centralized model predictive controller (MPC) for the laboratory canal that is able to handle known and unknown setpoint changes and disturbances, and also to draw further conclusions about controller design for this type of canals. A recently developed model for resonant canals, the Integrator Resonance, is implemented and successfully tested experimentally for the first time. A new method to achieve offset free control for model predictive control is developed and tested numerically and experimentally. A choice of control variables are tested: As opposed to the discharge which is generally used as the control action variable, a state space model is formulated by using the gate opening as control variable without the need of water level measurement downstream of the gates. The results are summarized and conclusions are presented for control of short and flat canals that are prone to resonance

An Integration of a Buffering Assessment Model Using Fuzzy Logic with Lean Management for Improving Highway Construction Process

This research develops an integration system framework of Last Planner system, and a proper buffering assessment model called FLBM using fuzzy logic. It focuses on increasing the reliability of buffers to match the actual degree of variation. Simulation of the model was accomplished in MATLAB using sample data to verify the model theoretically. A case study was simulated through FLBM to validate the credibility of the model

Experimental design and verification of a centralized controller for irrigation canals

This thesis aims to develop a predictive control for irrigation canals to improve the management of water resources. Water is necessary for life and it is a scarce good that we need for drinking, in the agriculture, etc. At the same time, it can constitute a serious threat in particular areas due to the difficulty to grow foods by the increasing of prolonged droughts. The agriculture holds an important part of the food chain and the water resources for agriculture are important, the problem is the water transport systems present low efficiencies in practice. The yield agriculture has to be optimized, because the goal of an operational water manager is to deliver the water to the irrigation sites accurately and efficiently. To improve the efficiency of the water transport systems is necessary to invest in automating the operation of irrigation canals. In order to fulfill these objectives, we define an overall control diagrams scheme in chapter 5 which splits the management of the canal control in different blocks. The management of a canal start from setting the demand delivery accurately taking into account the crops necessities during an irrigation cycle and establishing the gate trajectories for controlling the canal in each time step. In an ideal case, the system would be controlled but some factors which could deviated the desired state for the canal from the real canal state, as for instance, a disturbance introduced into the canal. In that circumstances, it would be necessary to introduce in our overall control diagram, other algorithms which could aid the watermaster to restore the desired state of the canal. These algorithms, developed and tested for us, are the CSI and GoRoSoBo algorithms. The first one defines a powerful tool in the management of a canal. The Watermaster establishes the gates positions and fixes the desired water level at checkpoints to fulfill a scheduled demand. In that sense, when someone introduce a disturbance into the canal perturbs the water level at checkpoints, so the scheduled deliveries cannot fulfilled by the watermaster. In such case, the water level measurements at these checkpoints could be sent to the CSI algorithms which calculates the real extracted flow and the current canal state along the canal, that is, the water level and velocity in all cross-sections of the canal. This task is performed by the CSI algorithm which has been designed in this thesis and tested in numerous numerical examples (chapter 7) and experimentally in a laboratory canal of the Technical University of Catalonia (chapter 8). The last one is the essential tool in the management of a canal, that is, a control algorithm operating in real-time. The GoRoSoBo algorithm (Gómez, Rodellar, Soler, Bonet) is a feedback control algorithm which calculates the optimum gates trajectories for a predictive horizon taking into account the current canal state obtained by CSI as well as the scheduled demands and the previous gate trajectories. GoRoSoBo has been designed in this thesis and tested in several numerical examples (chapter 10) as the Test-Case proposed by the ASCE Task Committee on Canal Automation Algorithms (chapter 11). In that sense, we propose a centralized control performance to manage the canal control. In addition to these two main contributions, many other smaller developments, minor results and practical recommendations for irrigation canal automation are presented throughout this thesis.Aquesta tesi té com a objectiu principal desenvolupar un control predictiu per a canals de reg i d'aquesta manera fer una aportació a la gestió dels recursos hídrics. L'aigua és un bé escàs i necessari per a la vida. És un recurs que fem un ús habitual d'ell, per consum propi, a la industria, com a font d'energia, a la agricultura.... .Un recurs tan preuat en zones amb escassetat per sequeres prologades constitueix un problema important, ja que afecta al desenvolupament de la zona. Concretament al sector de la agricultura pot provocar una davallada dels cultius i la incapacitat de cobrir les necessitats de la zona. L'agricultura és una part important de la cadena alimentària i els recursos hídrics per a l'agricultura són imprescindibles. Un greu problema a la agricultura son els baixos rendiments dels cultius moltes vegades relacionats amb sistemes de transport d'aigua poc eficients. La gestió dels recursos hídrics ha de ser optimitzada per obtenir rendiments competitius, ja que l'objectiu d'un gestor d'aigua és lliurar l'aigua de reg amb precisió i eficiència. Per millorar l'eficiència dels sistemes de transport d'aigua és necessari invertir en l'automatització dels canals de reg. Per complir aquests objectius, es defineix un esquema general de control al capítol 5, que divideix la gestió del control de canal en diferents blocs. La gestió d'un canal de reg s'inicia amb la programació de les demandes hídriques dels agricultors tenint en compte les necessitats dels diferents cultius durant un cicle de reg. Amb aquesta informació el watermaster tindria que establir les trajectòries de comporta o les accions de control per lliurar les demanades hídriques requerides als diferents punts del canal. En un cas ideal, el sistema seria controlat però a la realitat alguns factors externs podrien desviar l'estat desitjat del real, com per exemple extraccions de cabal desconeguts. En aquest cas, caldria introduir en el nostre diagrama general de control, altres algoritmes que podrien ajudar al WaterMaster a restablir l'estat desitjat. Aquests algoritmes, desenvolupats i testejats per nosaltres, són els algoritmes CSI i GoRoSoBo. CSI defineix una poderosa eina en la gestió d'un canal. El Watermaster estableix les posicions de les comportes i fixa el nivell d'aigua desitjat per complir amb les demandes hídriques programades en diferent punts del canal. En aquest sentit, quan algú introdueix una pertorbació altera el nivells de l'aigua al llarg del canal modificant els lliuraments programats inicialment de tal manera que no es podrien complir. En aquest cas, les mesures dels nivells d'aigua en diferents punts de control podrien ser enviats al algoritme CSI que tenint en compte aquest informació, les trajectòries de comporta i les demandes previstes calcularia el caudal real extret per les estructures de control i l'estat hidrodinàmic del canal, és a dir, el nivell de l'aigua i la velocitat en totes les seccions del canal. Aquesta tasca es duu a terme mitjançant l'algorisme CSI que ha estat dissenyat en aquesta tesi i provat en nombrosos exemples numèrics (capítol 7) i experimentalment en un canal de laboratori de la Universitat Politècnica de Catalunya (capítol 8). L'altre algorisme (GoRoSoBo) és l'eina essencial en la gestió d'un canal, és a dir, un algoritme de control que opera en temps real. GoRoSoBo (Gómez, Rodellar, Soler, Bonet) és un algorisme de control de retroalimentació (feedback) que calcula les trajectòries de comporta òptimes per un horitzó de predicció tenint en compte l'estat hidrodinàmic del canal en el moment actual i els caudals reals d'extracció obtinguts per CSI, així com les demandes programades i les trajectòries de comporta anteriors. GoRoSoBo ha estat dissenyat en aquesta tesi i provat en diversos exemples numèrics (capítol 10), així com als casos de prova proposats pel ASCE (Clemmens et a., 1998) (capítol 11) amb resultats excel·lent