[ ] SIENA

Stimulation Initiative for European Neural Applications

Esprit Project 9811



Case Studies of Successful Applications



Drinking Water Supply Management

Company background

Canal de Isabel II (CYII) is a public company responsible for regulation ,supply, treatment and distribution of drinking water over the whole are of Comunidad de Madrid (Madrid Region). Drinking water treated and distributed in Madrid in 1993 was of around 498.03 Hm3. In addition, Canal de Isable II has an annual capacity of waste water treatment of 202 Hm3. Canal de Isabel II high technology input in all company role is considerable, especially concerning water networks management.

Description of the problem

CYII has installed hundred of sensors in different autonomous station to measure water consumption. These measures are transmitted to the control centre to be processed. With these data the water requirements in different zones are calculated. However, within this scheme they want to solve three different problems. The first one is sensor validation that leads to missing values in the measurements and requires technical verification. Therefore, a sensor validation system is required to minimise this maintenance task. The second problem consist of estimating these missing values as a function of other variables that were actually measured. This can be done using a model that relates these variables and that could give an estimation of one variable as a function of the others. Finally, the third problem consists of estimating the future consumption using the past history of the variable along with another important variables such as temperature or rainfall measurements.

Neural Network Application

In order to give a solution to the above mentioned problems a neural network approach has been used due to its flexibility for modelling non-linear systems. Fuzzy logic technique was used for sensor validation while neural network was chosen for subsystem modelling and water consumption forecasting. Sensor validation gives a confidence level of sensor measurements which is used by the control engineers as an indication of possible fails. On the other hand, models of the different subsystems of the network is used not only as a second validation of the sensor measurements but also as a way to estimate sensor values when they are out of service. Neural networks are also used along with state space reconstruction techniques to make predictions of water consumption. Short term range forecasting (2 hours) along with long term range prediction (24 hours) are given so that engineers have an estimation of the future network charge and they can take control decision on the system.

Benefits

The IIC-system provides not only confidence on sensor measurements that ensure control engineers the current state of the network but also estimates future values of the network. Of course, not all variables can be predicted or modelled, because there are variables whose evolution do not follow any underlying model. However, neural network models increases the confidence on the measurements and therefore it leads to a saving in time and money for CYII.

Generalisation

Although, the sensor validation system along with subsystem modelling and variable forecasting have been installed in a water supplier company the technology used in this project can be used without minor changes in other industrial sectors where the state of the plant depends on different sensor measurements such as Chemical Reactors or industrial environments.

Contact persons

Francisco Cubillo, Canal de Isabel II - Santa Engracia, 125 - 28003 Madrid - Spain - Phone: +34 1 445 10 00; Fax: +34 1 446 31 01.

Alberto Pérez, Instituto de Ingeniería del Conocimiento - IIC Unversidad Autónoma de Madrid - Módulo C-XVI planta 2 - 28049 Madrid - Spain - Phone: +34 1 397 39 73; Fax: +34 1 397 39 72; alberto@irene.iic.uam.es.