IPS - ESCE – DML - Comunicações em congressos
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- A closed-loop control scheme for a class of piecewise affine systemsPublication . Nabais, João; Pina, Luís; Silva, Miguel; Ayala Botto, Miguel
- Qualitative comparison between two open water canal modelsPublication . Nabais, João; Ayala Botto, Miguel
- As marcas de distribuidor num contexto de recessão.Publication . Xara-Brasil, Duarte; Marreiros, Cristina; Dionísio, Andreia
- A importância da marca Portugal e da marca região de vinhos na internacionalização de um produtorPublication . Xara-Brasil, Duarte; Cravidão, Mário
- Linear model for canal poolsPublication . Nabais, João; Ayala Botto, MiguelWater is vital for human life.Water is used widespread from agricultural to industrial as well as simple domestic activities. Mostly due to the increase on world population, water is becoming a sparse and valuable resource, pushing a high demand on the design of efficient engineering water distribution control systems. This paper presents a simple yet sufficiently rich and flexible solution to model open-channels. The hydraulic model is based on the Saint-Venant equations which are then linearized and transformed into a state space dynamic model. The resulting model is shown to be able to incorporate different boundary conditions like discharge, water depth or hydraulic structure dynamics, features that are commonly present on any water distribution system. Besides, due its computational simplicity and efficient monitoring capacity, the resulting hydraulic model is easily integrated into safety and fault tolerant control strategies. In this paper the hydraulic model is successfully validated using experimental data from a water canal setup.
- Flexible framework for modeling water conveyance networksPublication . Nabais, João; Duarte, José; Ayala Botto, Miguel; Rijo, ManuelA flexible framework for modeling different water conveyance networks is presented. The network is modeled using a linear canal pool model based on the Saint-Venant equations to describe transportation phenomenon occurring in open channels. This model is used as a link to connect different nodes defined by gates or reservoirs. The linear pool model has interesting features namely the pool axis monitoring, the inflow along the pool axis and the ability to consider different boundary conditions. Based on these characteristics canal pool observers for leak detection and localization can be developed. It is shown that based on a finite difference scheme a good performance is obtained for low space resolution. The modeling framework is validated with experimental data from a real canal property of the Evora University. This is a challenging configuration due ´ to its strong canal pool coupling.
- Uma abordagem de marketing para os pequenos produtores de vinhoPublication . Xara-Brasil, Duarte; Cravidão, Mário
- Modular modeling for large scale canal networksPublication . Nabais, João; Lourenço, João; Ayala Botto, Miguel
- Sensor fault tolerant architecture for irrigation canalsPublication . Nabais, João; Mendonça, Luís F.; Ayala Botto, Miguel
- New Fault Isolation Architecture for Irrigation CanalsPublication . Nabais, João; Mendonça, Luís; Ayala Botto, MiguelIrrigation is one of the most consuming water resources in human activity. As water conveyance systems are commonly spatially distributed and crossing large regions it is important to guarantee their best efficiency. A fault diagnosis architecture is an important tool to increase efficiency in water conveyance systems. In the presence of leaks, unauthorized water extractions or water level sensor faults, the service level can be severely compromised. Recent literature deal with these situations as a unique fault of water extraction type. Isolating correctly each fault is important to access the real current state of the irrigation canals and proceed in accordance to restore its nominal conditions. This paper proposes a fault diagnosis architecture to distinguish common faults in water canals, considering either unexpected water extractions, gate faults and downstream water level sensor errors. The architecture is based on geometric and hydraulic parameters and therefore can be extended to existent irrigation canals. The proposed fault isolation architecture is an important tool to support maintenance services and be extended to fault tolerant controllers.