2,910 research outputs found
Sliding mode predictive control for chemical proces with time delay
16th IFAC World Congress Praga (República Checa), 03/07/2005A design of a novel model predictive controller is presented. The proposed Sliding Mode Predictive Control (SMPC) algorithm combines the design technique of Sliding-Mode Control (SMC) with Model based Predictive Control (MPC). The SMPC showed a considerable robustness improvement with respect to MPC in the presence of time delay, and showed an enhanced ability to handle set point changes in a nonlinear process. Its robustness was evaluated using a robustness plot, its performance was judged using a single input single output nonlinear mixing tank process with variable time delay
Adaptive control of a solar furnace for material testing
IFAC Adaptive Systems in Control and Signal Processing. Glasgow. Scotland. UK. 26/08/1998This paper presents an adaptive control system for controlling the temperature of a solar furnace, which is a high solar concentrating facility made up of heliostats tracking the sun and reflecting solar radiation onto a static parabolic concentrating system at the focal spot of which a high percentage of the solar energy collected by the collector system is concentrated in a small area. A large attenuator (shutter) placed between the collector system and the concentrator serves to control the amount of solar energy used for heating the samples placed at the focal spot. The paper shows the results obtained in the application of adaptive PI controllers to a solar furnace, incorporating feedforward action, anti-windup and slew rate constraint handling mechanisms
An Educational plant based on the Quadruple-tank process
7TH IFAC SYMPOSIUM ON ADVANCES IN CONTROL. 21/06/2006. MADRIDThis paper presents an experimental tank system developed at the University ofSeville for process control education. This plant is based on the well known quadruple-tank process and some modifications have been done in order to obtain a wide rangeof applications. The quadruple tank process is a multivariable laboratory plant of inter-connected tanks that can be easily configured to exhibit the effect of multivariable zero(minimum and non-minimum phase) on the system behavior, as well as the effect of nonlinear dynamics, saturation, constraints, etc.In the real plant implementation, the original structure of the process has been modifiedto offer a wide variety of uses for both educational and research purposes.Thus, differentplants can be configured such as one single tank, two or three cascaded tanks, a mixtureprocess and hybrid dynamics. Moreover the dynamics parameters of each tank can be setup by tuning the cross-section of the outlet hole of the tank. Furthermore, the real plant hasbeen implemented using industrial instrumentation and a PLC for the low level control.Supervision and control of the plant is carried out in a computer by means of OPC (Olefor Process Control) which allows one to connect the plant with a wide range of controlprograms such as LabView, Matlab or industrial SCADA.Ministerio de Ciencia y Tecnología DPI 2004-0744
A language for real time simulation of processes with boolean inputs and outputs
This paper deals with the problem of real time simulation of processes with boolean inputs and outputs. A language for this purpose and the programs that processes it is presented. The language allows the description of processes with simultaneous evolutions as a timed petri net type of description is used. Random failures can also be Introduced in the behaviour of the model. The language allows the control of a semlgraphic CRT in order to facilitate the task of following the model behaviour
Retrieving leaf area index from multi-angular airborne data
This work is aimed to demonstrate the feasibility of a methodology for retrieving bio-geophysical variables
whilst at the same time fully accounting for additional information on directional anisotropy. A model-based approach
has been developed to deconvolve the angular reflectance into single landcovers reflectances, attempting
to solve the inconsistencies of 1D models and linear mixture approaches. The model combines the geometric optics
of large scale canopy structure with principles of radiative transfer for volume scattering within individual
crowns. The reliability of the model approach to retrieve LAI has been demonstrated using data from DAISEX-
99 campaign at Barrax, Spain. Airborne data include POLDER and HyMap data in which various field plots
were observed under varying viewing/illumination angles. Nearly simultaneously, a comprehensive field data set
was acquired on specific crop plots. The inversions provided accurate LAI values, revealing the model potential
to combine spectral and directional information to increase the likely accuracy of the retrievals. In addition, the
sensitivity of retrievals with the angular and spectral subset of observations was analysed, showing a high consistency
between results. This study has contributed to assess the uncertainties with products derived from satellite
data like SEVIRI/MSG
Multi-robot task allocation problem with multiple nonlinear criteria using branch and bound and genetic algorithms
The paper proposes the formulation of a single-task robot (ST), single-robot task (SR), time-extended assignment (TA), multi-robot task allocation (MRTA) problem with multiple, nonlinear criteria using discrete variables that drastically reduce the computation burden. Obtaining an allocation is addressed by a Branch and Bound (B&B) algorithm in low scale problems and by a genetic algorithm (GA) specifically developed for the proposed formulation in larger scale problems. The GA crossover and mutation strategies design ensure that the descendant allocations of each generation will maintain a certain level of feasibility, reducing greatly the range of possible descendants, and accelerating their convergence to a sub-optimal allocation. The proposed MRTA algorithms are simulated and analyzed in the context of a thermosolar power plant, for which the spatially distributed Direct Normal Irradiance (DNI) is estimated using a heterogeneous fleet composed of both aerial and ground unmanned vehicles. Three optimization criteria are simultaneously considered: distance traveled, time required to complete the task and energetic feasibility. Even though this paper uses a thermosolar power plant as a case study, the proposed algorithms can be applied to any MRTA problem that uses a multi-criteria and nonlinear cost function in an equivalent way. The performance and response of the proposed algorithms are compared for four different scenarios. The results show that the B&B algorithm can find the global optimal solution in a reasonable time for a case with four robots and six tasks. For larger problems, the genetic algorithm approaches the global optimal solution in much less computation time. Moreover, the trade-off between computation time and accuracy can be easily carried out by tuning the parameters of the genetic algorithm according to the available computational power.Unión Europea 789051Ministerio de Ciencia, Innovación y Universidades IJC2018-035395-
La colección «Plantes De La Province De Grenada» de Pedro del Campo, en el herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial, Madrid (España)
CARRASCO, M. A., PEREA, D., ARAGÓN, C. F. & GARCÍA-CAMACHO, R. 2002. La Colección «Plantes de da Province de Grenada» de Pedro del Campo, en el herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial, Madrid (España). Bot. Complutensis 26: 93-103. En este trabajo presentamos una colección de plantas con interés histórico hallada en el herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial (Madrid). Fueron recolectadas en Granada por Pedro del Campo, distribuidas por E. Bourgeau en sus exsiccata de 1852 y utilizadas por Willkomm y Lange para establecer la distribución de las especies en la obra Prodromus florae hispanicae, según consta expresamente en ella. Además, muchos de estos materiales proceden de las localidades clásicas citadas por Boissier.CARRASCO, M. A., PEREA, D., ARAGÓN, C. F. & GARCÍA-CAMACHO, R. 2002. The sets «Plantes de la Province de Grenada» from Pedro del Campo, in the herbarium of Real Colegio Alfonso XII of San Lorenzo de El Escorial (Madrid, Spain). Bot. Complutensis 26: 93-103. This paper focuses on a set of plants, found in the Real Colegio Alfonso XII historical herbarium of San Lorenzo de El Escorial (Madrid). These plants which belonged to Pedro del Campo, were distributed in exsiccata by Bourgeau in 1852. The historical importance of these sheets is enhanced as they were used for Willkomm and Lange in order to establish the species corology in the classic Prodromus florae hispanicae, as clearly stated in that work. Furthermore, many of these sheets were collected in the localities cited by Boissier
Somatotype and digital dermatoglyphic in mexican football players
La valoración de la forma corporal y de las capacidades físicas es una
necesidad para la selección, clasificación y entrenamiento de los jugadores de
futbol. El presente estudio examinó en futbolistas profesionales mexicanos (N =
49) la relación entre clases de somatotipo y clases de capacidades físicas de
acuerdo a dermatoglifia dactilar. Las frecuencias de clases de somatotipo y
clases de capacidad física fueron comparadas entre subgrupos de futbolistas.
Una mayor proporción de futbolistas se caracterizó por somatotipo mesomorfo
balanceado con dermatoglifia tipo 2 y 3 correspondiente a fuerza, fuerza explosiva y velocidad. Esto es consistente con hallazgos previos en futbolistas
chilenos y brasileños, extendiendo por tanto la evidencia disponible acerca de
somatotipo y dermatoglifia en futbolistas latinoamericanosEvaluating body shape and capacities is needed for selection, classification and
training of football players. The present study examined in Mexican male
football players (N = 49) the relationship between types of somatotype and
types of physical capacities according to digital dermatoglyphics. The
frequencies of types of somatotype and of physical capacities were compared
between football players subgroups. A higher proportion of football players was
characterised by a balanced mesomorph somatotype with dermatoglyphic type
2 and 3 corresponding to strength, explosive strength and velocity. This is
consistent with previous findings in Chilenean and Brazilian footballers,
Therefore extending the available evidence of somatotype and dermatoglyphics
in Latin American football player
Studies for the application of an adaptative controller to hydroturbine generators
This paper describes some studies made towards the automatization of hydroturbine generators with microcomputers. The overall design will include an automata controlling the starting-up and shutting-down procedure as well as an self-tuning regulator for the speed control. A self-tuning regulator based on the classical pole-assignment-method is studied. The algorithm uses a fast procedure for solving the polynomial equation implicit to selfturner regulator. This procedure is very simple from a computational point of view as only applications of elementary transformations on a 2 x 2 polynomial matrix are needed.The algorithm has been programmed on a Digital PDP 1103 computer and applied to some test problems
Simulador de redes eléctricas
Se presenta un simulador de redes eléctricas para el entrenamiento de operadores de centros de control de las mismas. El simulador es el resultado de una primera fase de un proyecto de investigación de UNESA, e incorpora las funciones fundamentales para redes pequeñas. El simulador se ha implementado sobre un computador de 16 bits y dispone de dos consolas semigráficas para el instructor y operador desde donde se puede actuar sobre la red y seguir la evolución de la misma
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