Canal de Provence

Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Measurement network on hydraulic system includes many sensors subject to failure or deviation, and spread over a huge area. In addition discharge and volume measurements in open channel hydraulic networks are characterized by large uncertainties. To overcome this kind of problem, in process control industrial applications, data reconciliation is more and more used. The objective of the data reconciliation is to take advantage of information redundancy on a system to make a cross-checking of real-time measurements. Using this information redundancy, a data reconciliation module allows to detect inconsistent measurements, measurement deviations and provides corrected values whether the initial measurements are valid, biased or invalid. A derived consequence is to better schedule the maintenance of sensors. A data reconciliation module, based on the measurements from the hydraulic network, has been recently developed and implemented in the SCP's supervisory system. The software has initially been used on a daily basis to check the measured flow on the main canal. It has then been adapted in order to run every 15 minutes on a distribution network including pipes, canals, and tanks. The paper presents first the theory of the Canal de Provence data reconciliation application. The basic model is an hydraulic network with a series of nodes corresponding to balance equations (inflows, outflows, and storage). Constrained data reconciliation is used in order to satisfy the non-negativity of the hydraulic variables and the mass balance relations. The results are corrected values for measured variables and proposed values for non-measured quantities. A statistical analysis of the results is performed. This analysis allows to evaluate the uncertainties attached to the estimated flows and volume values. It allows also to detect invalid measurements, drift of sensors and to decide which maintenance operations to perform. Secondly, field examples are presented: measured and re-estimated flow values with their standard deviations, detection of invalid sensors, performed maintenance operation. The data reconciliation is situated just after the measurement process and takes place in the decision process for diagnosis, identification and control

Multi-variable approach for the command of Canal de Provence Aix nord water supply subsystem, A

Presented during the USCID water management conference held on October 13-16, 2004 in Salt Lake City, Utah. The theme of the conference was "Water rights and related water supply issues."Includes bibliographical references.The Canal de Provence is fully user oriented. Water users can take the water freely without respecting neither rotation nor any sort of priority allocation. Its structure. consisting of main free flow canals and pressurized distribution networks. is well adapted to this strategy. The main canal must be able to face the regime variations coming from this kind of distribution. The current regulation conception first split the whole system into a series of assumed independent sub-systems. The multi-variable aspect is then taken into account by a coordination of the sub-systems adjustment, carrying the discharge correction from downstream to upstream. The Aix nord branch control presents interesting characteristics such as many different hydraulic entities (free surface canals. reservoirs. pumping stations) and operating constraints (levels in reservoirs. optimization of pumping costs). A real multi-variable approach will allow managing all gate and pump operations and all constraints at the same time. leading to a global optimisation of the whole system. The MIMO (Multi Input - Multi Output) model is established from transfer functions. the coefficients of which are deduced from the physical and geometrical characteristics of the system. A Linear Quadratic Regulator is computed and tested on a complete non-linear numerical model of the hydraulic system. The system to be controlled includes many discrete commands (pump operations) that are not managed by a classical optimal control. These commands are treated apart, leading to calculated perturbations that are introduced in the regulator.Proceedings sponsored by the U.S. Department of the Interior, Central Utah Project Completion Act Office and the U.S. Committee on Irrigation and Drainage

Influence of Canal Geometry and Dynamics on Controllability

This paper presents the results of the Task Committee on Canal Automation Algorithms with regard to the influence of canal properties on the controllability of irrigation canals. While the control provided by individual algorithms was not evaluated, studies were performed to illustrate inherent hydraulic limitations—the inability of canal pools to recover rapidly from disturbances or flow perturbations. Studies were performed in nondimensional form to develop a better understanding of how pool properties influence pool response. Three such studies were performed. First, nondimensional backwater curves were developed for a range of canal conditions. The second study involved the propagation of waves initiated at the upstream end of a canal pool, as this is influenced by downstream boundary conditions. Finally, the response of pools to downstream withdrawals was examined in terms of their sluggish recovery even when the correct flow change is applied upstream. These results will help in understanding how canal properties influence the ability of operators to effectively control a canal either manually or automatically, and should influence future design practices

Catalogue des cas-tests avec justification des motifs

In this first report of a research for RENAULT, a preliminary list of benchmarks is defined.Etude de faisabilité de la simulation numérique de l'usinag

Describing the motion of the tool

In the frame of the development of a simulation tool for machining, this report is devoted to the description of the tool motion.Etude de faisabilité numérique de l'usinag

Taking account of the fact that the stiffness of the work varies during the machining

In the frame of the feasability study of machining simulation, this report is devoted to the study of the stiffness variation during the machining processEtude de faisabilité de la simulation numérique de l'usinag

Modelling the cutting forces

In the frame of the feasability study of a machining simulation, this report is devoted to the prediction of the cutting forces.Etude de faisabilité de la simulation numérique de l'usinag

Procedures for the identification of the load parameters

In the frame of the feasability study of a machining simulation, this report describes how to compute the nodal components of the cutting forces on the finite element mesh.Etude de faisabilité de la simulation numérique de l'usinag

benchmark catalogue

This report describes the benchmarks which have been done with the machining simulation prototype.Etude de faisabilité de la simulation numérique de l'usinag