Manuel Rijo

ADAPTIVE AND NON-ADAPTIVE MODEL PREDICTIVE CONTROL OF AN IRRIGATION CHANNEL

The performance achieved with both adaptive and non-adaptive Model Predictive Control (MPC) when applied to a pilot irrigation channel is evaluated. Several control structures are considered, corresponding to various degrees of centralization of sensor information, ranging from local upstream control of the different channel pools to multivariable control using only proximal pools, and centralized multivariable control relying on a global channel model. In addition to the non-adaptive version, an adaptive MPC algorithm based on redundantly estimated multiple models is considered and tested with and without feedforward of adjacent pool levels, both for upstream and downstream control. In order to establish a baseline, the results of upstream and local PID controllers are included for comparison. A systematic simulation study of the performances of these controllers, both for disturbance rejection and reference tracking is shown.

Local Automatic Control Modes in an Experimental Irrigation Canal

The paper presents twolocal PI automatic control modes developed,tuned and verified in an experimentalautomatic canal. The canal was used as aphysical model and it will support furtherstudies on canal automation domain. Thecontrol algorithms are installed in localPLCs with the objective of controlling thewater depths immediately upstream anddownstream of the corresponding checkgates. The strategy adopted to tune the PIcontrollers was to compare the frequencyresponse of the state space model, whichrelies on the linearized Saint-Venantequations, with a simple model consideringeach canal pool as a reservoir (reservoirmodel). The obtained results for thecontrol gains were validated by fieldtests. A few simulation results are alsopresented as well as the experimentalfacility and the main configuration of theSCADA developed for the canal supervisionand monitoring.

Control of a water delivery canal with cooperative distributed MPC

This article addresses the problem of controlling pool levels in a water delivery canal using a novel cooperative distributed MPC control algorithm that incorporates stability constraints. According to a distributed control strategy, a local control agent is associated to all canal gates (actuators). In order to achieve cooperative action, each control agent computes the corresponding gate position (manipulated variable) by performing the minimization of a cost function that considers not only its local control objectives, but also the ones of their immediate neighbors. For this purpose, a MPC algorithm with stability constraints is used (SIORHC). At the beginning of each sampling interval, local control agents exchange information with their neighbors and adjust their decisions in an iterative way. The resulting distributed MPC is denoted D-SIORHC and yields a stable closed-loop. Experimental results are provided to show the influence of the controller configuration parameters on the resulting performance.

Supervision and Water Depth Automatic Control of an Irrigation Canal

A supervisory and control system developed for a Portuguese irrigation canal system equipped with motorized sluice gates and buffer reservoirs is presented. The article discusses the development and tuning of the canal systems controllers: manual controllers for direct control of gate position and gate flow controllers, which maintain discharge at predefined values; automatic controllers for water depth control upstream from check structures. System hydraulics was simulated using an unsteady flow open-channel model based on the complete Saint-Venant equations. After field calibration and validation, the model was used for tuning the water depth controllers. The automatic upstream water depth control is based on local proportional-integral controllers. Controller gains were determined using optimization tools provided by the hydraulic simulator. These procedures tune the controller parameters globally, considering a given set of inflow variations. Finally, the paper presents simulated control tests results and an analysis of controller performances. Under the test conditions, the controller was able to drive water levels back to their setpoint rapidly and without instabilities and also guaranteeing stable gates movement.

Multi-Platform Controller Interface for SCADA Application

Abstract This paper concerns the development of a SCADA-Controller Interface (SCI) application for an open-channel experimental facility. Water delivery canals are complex and spatially distributed systems. The proposed application is to be applied to test control algorithms developed by several research groups with different technical approaches. The proposed interface allows the development of controllers in different environments – C/C++, MATLAB/Simulink, and GNU Prolog – and may be easily extended to other environments. The experimental facilities with the used instrumented canal, the programmable logic controller (PLC) network and the SCADA system are also described in this paper. Finally, some software experimental results are presented.

Distributed LQG control of a water delivery canal with feedforward from measured consumptions

This work addresses the design of distributed LQG controllers for water delivery canals that include feedforward from local farmer water consumptions. The proposed architecture consists of a network of local control agents, each connected to one of the canal pools and sharing information with their neighbors in order to act in a coordinated way. In order to improve performance, the measurement of the outflow from each pool is used as a feedforward signal. Although the feedforward action is local, it propagates due to the coordination procedure. The paper presents the distributed LQG algorithm with feedforward and experimental results in a large scale pilot water delivery canal.

Multivariable and Distributed LQG Control of a Water Delivery Canal

AbstractThis paper addresses the problem of the development of a distributed linear quadratic Gaussian (LQG) controller for a water delivery canal. The control structure proposed relies on a set of LQG control agents interconnected through a communication network. Each of these local control agents controls a canal reach made of a pool and the corresponding downstream gate and receives information (output signal and control moves) only from the corresponding canal reach and the ones that are adjacent to it. An algorithm is proposed to achieve coordinated action of the different local control agents. This distributed control structure is compared with centralized multivariable LQG control. Several aspects with incidence on performance are addressed, including the modification of the quadratic cost to ensure a constraint on closed-loop poles, the use of a nonlinear filter to limit noise effects, and the impact of a quantization commonly forced in gate position. Experimental results obtained in a pilot canal...

Flow Rate Measurements under Sluice Gates

AbstractSluice gates are commonly used in canals for control and measurement of the flow. The discharge under sluice gates can be determined through the energy-momentum method (EM), the orifice flo...