Other affiliations: Ferdowsi University of Mashhad
Bio: Vicente Feliu-Batlle is an academic researcher from University of Castilla–La Mancha. The author has contributed to research in topic(s): Control theory & PID controller. The author has an hindex of 16, co-authored 66 publication(s) receiving 1050 citation(s). Previous affiliations of Vicente Feliu-Batlle include Ferdowsi University of Mashhad.
TL;DR: In this paper, a shunt active power filter based on a pulsewidth modulation dc-to-ac voltage source converter has been designed to compensate harmonic currents of nonlinear loads connected to the mains.
Abstract: This paper presents the detailed design, analysis, and application of the controller for a shunt active power filter based on a pulsewidth modulation dc-to-ac voltage source converter. The controller is mainly tailored to compensate harmonic currents of nonlinear loads connected to the mains. However, it can also achieve reactive-power compensation and mains-current balancing when required. The controller has a two-layer structure. The outer layer generates the current references for the inner layer. The former uses a plug-in discrete-time repetitive algorithm for current-harmonic compensation, a proportional-integral algorithm to maintain the dc-capacitor voltage in spite of unmodeled losses and a reactive-power-reference generator. The inner layer uses state-feedback with integral action for current control. The repetitive controller is justified to improve the tracking of the periodic current references required by the active filters. The stability of the resulting closed-loop system is studied and some indication of the system robustness is given. The proposed controller has been tested in a prototype with balanced and unbalanced nonlinear loads. A discrete-time model of the filter has been used from the beginning. The microcomputer delay when calculating the controller output and the delay due to the anti-aliasing filters have been included in the inner system state-variable model
01 Jun 2007-Control Engineering Practice
TL;DR: In this article, a robust fractional order controller is proposed for controlling main irrigation canals with variable dynamical parameters based on robust PIDs, which exhibit the same robustness as the previous PID to time delay and gain changes.
Abstract: A new method is proposed for controlling main irrigation canals with variable dynamical parameters based on robust fractional order controllers. A methodology for designing PID controllers robust to changes in the time delay and the gain is presented first. Then this method is generalized to design fractional controllers that exhibit the same robustness as the previous PID to time delay and gain changes, but are noticeably more robust to variations in the dominant time constant of the process. This method is applied to control main irrigation canals. Extensive numerical simulations using the dynamic model of a real canal were carried out. Then experimental results were obtained in a prototype canal that proved the effectiveness of the proposed control method in terms of performance and robustness.
01 Mar 2009-Journal of Process Control
TL;DR: In this article, the authors proposed a new methodology to design fractional integral controllers combined with Smith predictors, which are robust to high frequency model changes, in particular, special attention is paid to time delay changes.
Abstract: This paper proposes a new methodology to design fractional integral controllers combined with Smith predictors, which are robust to high frequency model changes. In particular, special attention is paid to time delay changes. These controllers show also less sensitivity to high frequency measurement noise and disturbances than PI or PID controllers. This methodology is applied to design controllers for water distribution in a main irrigation canal pool. Simulated results of standard PI and PID controllers plus a Smith predictor, and the controller developed in this paper are compared when applied to the dynamical model of a real main irrigation canal pool showing that our controller exhibits better and more robust features than these. Moreover our controller is compared with other more complex control techniques as predictive control and robust H∞ controllers, exhibiting better or similar performances than these.
TL;DR: In this article, the authors proposed a new strategy for the control of water distribution in an irrigation main canal pool characterized by large time-varying time delays using fractional order PI controllers combined with Smith predictors that yield control systems which are robust to changes in the process time delay.
Abstract: This paper proposes a new strategy for the control of water distribution in an irrigation main canal pool characterized by large time-varying time delays. Time delays may change drastically in an irrigation main canal pool as a consequence of variations in its hydraulic operation regime. An original methodology is developed to design fractional order PI controllers combined with Smith predictors that yield control systems which are robust to changes in the process time delay. This methodology is applied to solve the problem of effective water distribution control in an irrigation main canal pool. Simulated results of standard PI and PID controllers plus a Smith predictor are compared with the controller developed in this paper when applied to the dynamic model of a real irrigation main canal pool. The simulation results show that the proposed controller outperforms standard controllers in terms of performance and robustness.
TL;DR: In this article, a simple fractional order controller combined with a Smith predictor scheme was proposed for controlling the temperature of a steel slab reheating furnace, where the preheating zone of this process was obtained from an identification procedure applied in an industrial furnace.
Abstract: This paper proposes a simple fractional order controller combined with a Smith predictor scheme for controlling the temperature of a steel slab reheating furnace. The dynamic model of the preheating zone of this process is obtained from an identification procedure applied in an industrial furnace. This identification procedure yields a second order plus time delay transfer function which undergoes large time delay changes. A fractional order integral controller combined with a Smith predictor is therefore designed. Simulated results compare the performances of the proposed fractional order controller with a standard PI controller, also combined with a Smith predictor, an LQR controller, and an H ∞ robust controller, in the case of the nominal process, and when the time delay varies. Four performance indexes have been used in this comparison: three related to the output performance (settling time, overshooting, and integral absolute error (IAE)), and a fourth one related to the control effort (TV). The analysis of these indexes shows that the simple fractional order controller provides lower values of the compared indexes when time delay becomes much higher than the nominal value.
••01 Jan 2015
01 Jan 1994
TL;DR: The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images.
Abstract: MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.
01 Nov 1981
TL;DR: In this paper, the authors studied the effect of local derivatives on the detection of intensity edges in images, where the local difference of intensities is computed for each pixel in the image.
Abstract: Most of the signal processing that we will study in this course involves local operations on a signal, namely transforming the signal by applying linear combinations of values in the neighborhood of each sample point. You are familiar with such operations from Calculus, namely, taking derivatives and you are also familiar with this from optics namely blurring a signal. We will be looking at sampled signals only. Let's start with a few basic examples. Local difference Suppose we have a 1D image and we take the local difference of intensities, DI(x) = 1 2 (I(x + 1) − I(x − 1)) which give a discrete approximation to a partial derivative. (We compute this for each x in the image.) What is the effect of such a transformation? One key idea is that such a derivative would be useful for marking positions where the intensity changes. Such a change is called an edge. It is important to detect edges in images because they often mark locations at which object properties change. These can include changes in illumination along a surface due to a shadow boundary, or a material (pigment) change, or a change in depth as when one object ends and another begins. The computational problem of finding intensity edges in images is called edge detection. We could look for positions at which DI(x) has a large negative or positive value. Large positive values indicate an edge that goes from low to high intensity, and large negative values indicate an edge that goes from high to low intensity. Example Suppose the image consists of a single (slightly sloped) edge:
TL;DR: In this paper, a considerable collection of totally free of expense Book for people from every single stroll of life has been gathered to gather a sizable library of preferred cost-free as well as paid files.
Abstract: Our goal is always to offer you an assortment of cost-free ebooks too as aid resolve your troubles. We have got a considerable collection of totally free of expense Book for people from every single stroll of life. We have got tried our finest to gather a sizable library of preferred cost-free as well as paid files. Whatever our proffesion, the art of electronics can be excellent resource for reading. Find the existing reports of word, txt, kindle, ppt, zip, pdf, as well as rar in this site. You can definitely check out online or download this book by below. Currently, never miss it. This is really going to save you time and your money in something should think about. If you're seeking then search around for online. Without a doubt there are several these available and a lot of them have the freedom. However no doubt you receive what you spend on. An alternate way to get ideas would be to check another the art of electronics. GO TO THE TECHNICAL WRITING FOR AN EXPANDED TYPE OF THIS THE ART OF ELECTRONICS, ALONG WITH A CORRECTLY FORMATTED VERSION OF THE INSTANCE MANUAL PAGE ABOVE.
01 Jul 2008-Control Engineering Practice
TL;DR: In this article, a method for tuning the PI λ D μ controller is proposed to fulfill five different design specifications, including gain crossover frequency, phase margin, and iso-damping property of the system.
Abstract: This paper deals with the design of fractional order PI λ D μ controllers, in which the orders of the integral and derivative parts, λ and μ , respectively, are fractional. The purpose is to take advantage of the introduction of these two parameters and fulfill additional specifications of design, ensuring a robust performance of the controlled system with respect to gain variations and noise. A method for tuning the PI λ D μ controller is proposed in this paper to fulfill five different design specifications. Experimental results show that the requirements are totally met for the platform to be controlled. Besides, this paper proposes an auto-tuning method for this kind of controller. Specifications of gain crossover frequency and phase margin are fulfilled, together with the iso-damping property of the time response of the system. Experimental results are given to illustrate the effectiveness of this method.