Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/1126
2015-08-03T21:56:59ZWater demand forecasting for the optimal operation of large-scale drinking water networks: the Barcelona case study
http://hdl.handle.net/2117/76478
Water demand forecasting for the optimal operation of large-scale drinking water networks: the Barcelona case study
Sampathirao, Ajay Kumar; Grosso Pérez, Juan Manuel; Sopasakis, Pantelis; Ocampo-Martínez, Carlos; Bemporad, Alberto; Puig Cayuela, Vicenç
Drinking Water Networks (DWN) are large-scale multiple-input multiple-output systems with uncertain disturbances (such as the water demand from the consumers) and involve components of linear, non-linear and switching nature. Operating, safety and quality constraints deem it important for the state and the input of such systems to be constrained into a given domain. Moreover, DWNs' operation is driven by time-varying demands and involves an considerable consumption of electric energy and the exploitation of limited water resources. Hence, the management of these networks must be carried out optimally with respect to the use of available resources and infrastructure, whilst satisfying high service levels for the drinking water supply. To accomplish this task, this paper explores various methods for demand forecasting, such as Seasonal ARIMA, BATS and Support Vector Machine, and presents a set of statistically validated time series models. These models, integrated with a Model Predictive Control (MPC) strategy addressed in this paper, allow to account for an accurate on-line forecasting and flow management of a DWN.
2014-01-01T00:00:00ZOn the assessment of tree-based and chance-constrained predictive control approaches applied to drinking water networks
http://hdl.handle.net/2117/76384
On the assessment of tree-based and chance-constrained predictive control approaches applied to drinking water networks
Grosso Pérez, Juan Manuel; Maestre Torreblanca, José María; Ocampo-Martínez, Carlos; Puig Cayuela, Vicenç
Water systems are a challenging problem because of their size and exposure to uncertain influences such as the unknown demands or the meteorological phenomena. In this paper, two different stochastic programming approaches are assessed when controlling a drinking water network: chance-constrained model predictive control (CC-MPC) and tree-based model predictive control (TB-MPC). Under the former approach, the disturbances are modeled as stochastic variables with non-stationary uncertainty description, unbounded support and quasi concave probabilistic distribution. A deterministic equivalent of the related stochastic problem is formulated using Boole’s inequality and a uniform allocation of risk. In the later approach, water demand is modelled as a disturbance rooted tree where branches are formed by the most probable evolutions of the demand. In both approaches, a model predictive controller is used to optimise the expectation of the operational cost of the disturbed system.
2014-01-01T00:00:00ZOutput-feedback model predictive control of sewer networks through moving horizon estimation
http://hdl.handle.net/2117/28546
Output-feedback model predictive control of sewer networks through moving horizon estimation
Joseph Duran, Bernat; Ocampo-Martínez, Carlos; Cembrano Gennari, Gabriela
Based on a simplified control-oriented hybrid linear delayed model, model predictive control (MPC) of a sewer network designed to reduce pollution during heavy rain events is presented. The lack of measurements at many parts of the system to update the initial conditions of the optimal control problems (OCPs) leads to the need for estimation techniques. A simple modification of the OCP used in the MPC iterations allows to formulate a state estimation problem (SEP) to reconstruct the full system state from a few measurements. Results comparing the system performance under the MPC controller using full-state measurements and a moving horizon estimation (MHE) strategy solving a finite horizon SEP at each time instant are presented. Closed-loop simulations are performed by using a detailed physically-based model of the network as virtual reality.
2014-01-01T00:00:00ZAn application of chance-constrained model predictive control to inventory management in hospitalary pharmacy
http://hdl.handle.net/2117/28475
An application of chance-constrained model predictive control to inventory management in hospitalary pharmacy
Maestre Torreblanca, José María; Velarde, Pablo; Jurado, Isabel; Ocampo-Martínez, Carlos; Isla Tejera, Beatriz; del Prado, José Ramón
Inventory management is one of the main tasks that the pharmacy department has to carry out in a hospital. It is a complex problem that requires to establish a tradeoff between different and contradictory optimization criteria. The complexity of the problem is increased due to the constraints
that naturally arise in this type of applications. In this paper, which corresponds to preliminary works performed to implement advanced control techniques for pharmacy management in two Spanish hospitals, we propose and assess chance-constrained model predictive control (CC-MPC) as a mean to relieve this issue.
2014-01-01T00:00:00ZChance-constrained model predictive control applied to inventory management in hospitalary pharmacy
http://hdl.handle.net/2117/28328
Chance-constrained model predictive control applied to inventory management in hospitalary pharmacy
Maestre Torreblanca, José María; Ocampo-Martínez, Carlos
This extended abstract addresses the preliminary results of applying uncertainty handling strategies and advanced control techniques to the inventary management of hospitality pharmacy. Inventory management is one of the main tasks that a pharmacy department has to carry out in a hospital. It is a complex problem because it requires to establish a tradeoff between contradictory optimization criteria. The final goal of the proposed research is to update the inventory management system of hospitals such that it is possible to reduce the average inventory while maintaining preestablished clinical guarantees.
2014-01-01T00:00:00ZOn the comparison of predictive control and command governor approaches for operational management of drinking water networks: a case study
http://hdl.handle.net/2117/27912
On the comparison of predictive control and command governor approaches for operational management of drinking water networks: a case study
Tedesco, Francesco; Ocampo-Martínez, Carlos; Cassavola, Alessandro; Puig Cayuela, Vicenç
This paper evaluates the application of command governor (CG) strategy for the operational control of drinking water networks (DWN) given their large-scale and complex nature, the permanent and relevant effect of the disturbances (water demands) and their marginal stability feature. Moreover, the performance improvement offered by CG is compared with the application of model predictive control for the same management purposes and in the same context. The paper also discusses the effectiveness of both strategies and highlights the advantages of each approach. The Barcelona DWN is considered as case study for the undertaken assessment analysis.
2014-01-01T00:00:00ZCombining CSP and MPC for the operational control of water networks: Application to the Richmond case study
http://hdl.handle.net/2117/27677
Combining CSP and MPC for the operational control of water networks: Application to the Richmond case study
Sun, Congcong; Puig Cayuela, Vicenç; Cembrano Gennari, Gabriela
This paper presents the combination of linear Model Predictive Control (MPC) with Constraint Satisfaction Problem (CSP) for the operational control of drinking water networks. The methodology has been divided into two functional layers: First, a CSP algorithm is used to transfer non-linear pressure equations of drinking water networks (DWNs) into linear constraints, which can enclose feasible solution of the hydraulic non-linear problem during the optimizing process. Then, a linear MPC with added linear constraints is solved to generate control strategies which consider control objectives. Finally, the proposed approach is simulated using Epanet to represent the real DWNs. PLIO, which is a generic operational tool for controlling water networks that uses non-linear MPC, is used for validation. The Richmond water system is used as a case study.
2014-01-01T00:00:00ZReal-time monitoring and control for efficient management of drinking water networks: Barcelona case study
http://hdl.handle.net/2117/27629
Real-time monitoring and control for efficient management of drinking water networks: Barcelona case study
Cembrano Gennari, Gabriela; Puig Cayuela, Vicenç; Ocampo-Martínez, Carlos; Quevedo Casín, Joseba Jokin; Mirats Tur, Josep Maria; Meseguer Amela, Jordi; Ariño Tarrago, Ramon; López Martínez, Silvia
Drinking water utilities in urban areas are facing new challenges in their real-time operation: limited water resources, intensive energy requirements, a growing population, a costly and ageing infrastructure, increasingly stringent regulations, and increased attention towards the environmental impact of water use. The efficient use of resources is becoming a priority for water managers and the recent advances in ICT technologies can provide solutions to this end. Real-time management in water networks may be considered as a process comprising two different levels: (i) Monitoring, which is concerned with the observation and estimation of the current state of a system and the detection/diagnosis of abnormal situations. It is achieved through sensors and communications technology, together with mathematical models; and (ii) Control, related to computing and applying the best admissible control strategies for network actuators. Optimal control seeks to optimize a given set of operational goals related to the network performance, such as efficiency in resource use, environmental impact, etc.
Real-time monitoring and control techniques can significantly improve the use of water and energy resources in water networks. This paper addresses the developments of the European project EFFINET, which proposes a novel integrated water resource management system based on advanced ICT technologies of automation and telecommunications for improving the efficiency of drinking water networks in terms of water use, energy consumption, water loss minimization, and water quality guarantees by addressing the real-time monitoring and control levels.
2014-01-01T00:00:00ZHybrid control-oriented modeling of combined sewer networks: Barcelona case study
http://hdl.handle.net/2117/27606
Hybrid control-oriented modeling of combined sewer networks: Barcelona case study
Joseph Duran, Bernat; Ocampo-Martínez, Carlos; Cembrano Gennari, Gabriela
A hybrid linear model for real-time optimization-based control of a combined sewer network has been developed to be used for the minimization of pollution during storm events. The model takes into account delays and attenuation in sewers together with piecewise linear approximations for flow over weirs, overflows in junctions and flow re-entering the network after overflows. Using the proposed model, an Optimal Control Problem (OCP) is formulated, which can be efficiently solved by means of a mixed integer linear or quadratic programming problem. The performance of a Model Predictive Control (MPC) strategy solving consecutive OCPs is assessed by means of closed-loop simulations using a physically-based complex model as virtual reality.
2014-01-01T00:00:00ZCoordinating multi-layer MPC for complex water systems
http://hdl.handle.net/2117/27605
Coordinating multi-layer MPC for complex water systems
Sun, Congcong; Puig Cayuela, Vicenç; Cembrano Gennari, Gabriela
In this paper, coordinating technique for the multi-layer model predictive control (MPC) of complex water network is proposed. A multi-layer topology structure resulting from a functional decomposition of water network is briefly presented. Inside each layer, a MPC based controller is used. Between the related two layers, a multi-layer coordinating mechanism is provided to generate control strategies which consider objectives and time scales of both layers. Optimal Path Method (OPM) is used to estimate aggregated water price for the whole layer. The case study is the Catalunya Regional Water Network. Simulation results based on an aggregate model of this network are provided.
2014-01-01T00:00:00Z