1,682 research outputs found
Distributed Control of Power Grids
No full textThis chapter provides a short introduction to the part of this volume dealing with distributed control of power grids. A brief description of some of the challenges facing existing power grids from a control perspective is given. The research community dealing with distributed control of power grids is highly active, and there already exists a vast literature on the topic. A coverage of this literature with any pretense of full or partial completeness would be difficult (if not impossible) and is not in any way attempted in this brief introduction
Safe distancing in the time of COVID-19
No full textThe spread of viruses such as SARS-CoV-2 brought new challenges to our society, including a stronger focus on safety across all businesses. Many countries have imposed a minimum social distance among people in order to ensure their safety. This brings new challenges to many customer-related businesses, such as restaurants, offices, theaters, etc., on how to locate their facilities (tables, seats etc.) under distancing constraints. We propose a parallel between this problem and that of locating wind turbines in an offshore area. The discovery of this parallel allows us to apply Mathematical Optimization algorithms originally designed for wind farms, to produce optimized facility layouts that minimize the overall risk of infection among customers. In this way we can investigate the structure of the safest layouts, with some surprising outcomes. A lesson learned is that, in the safest layouts, the facilities are not equally distanced (as it is typically believed) but tend to concentrate on the border of the available area—a policy that significantly reduces the overall risk of contagion
The Math Diet:Weigh your food and lose body weight
No full textTræt af slankekure? Træt af at tælle kalorier? Træt af ’det-må-du-ikke-spise’ og yoyovægt?Matematisk vægttab har de seneste år taget slankekurstrætte danskere med storm. Nu kommer bogen bag succesen.Det matematiske vægttab udnytter, at kroppen hver eneste dag naturligt taber sig en lille smule. Metoden er simpel: Du må spise, hvad du har lyst til – slik, kager og chips. Eneste regel er, at du i dag skal veje mindre, end du gjorde i går.Matematisk vægttab arbejder derfor hverken med kalorietælling eller afvisning af bestemte former for mad. Tværtimod viser bogen, at du kan tabe dig med matematisk præcision, mens du spiser alle dine livretter.Og dermed er der matematisk garanti for vægttab.Professor Jakob Stoustrup er en af verdens førende eksperter i reguleringsteori, og han har udviklet metoden matematisk vægttab på baggrund af avancerede, matematiske formler. I bogen gør han de avancerede beregninger bag metoden lette at forstå, mens hans sundhedsuddannede datter Anna Lei Stoustrup fortæller, hvorfor du får det nemmeste og sundeste vægttab ved at kombinere matematisk vægttab med sund mad og motion.Som inspiration til et sundt vægttab med Matematisk vægttab indeholder bogen både et træningsprogram og 50 lækre opskrifter.This book presents a method for losing weight based on control theory. The algorithm uses body weight measurements as a basis for computing every day an amount of food. Consuming this amount of food ensures that a daily weight target is followed with mathematical precision
Sequential convex relaxation for convex optimization with bilinear matrix equalities
No full textWe consider the use of the nuclear norm operator, and its tendency to produce low rank results, to provide a convex relaxation of Bilinear Matrix Inequalities (BMIs). The BMI is first written as a Linear Matrix Inequality (LMI) subject to a bi-affine equality constraint and subsequently rewritten into an LMI subject to a rank constraint on a matrix affine in the decision variables. The convex nuclear norm operator is used to relax this rank constraint. We provide an algorithm that iteratively improves on the sum of the objective function and the norm of the equality constraint violation. The algorithm is demonstrated on a controller synthesis example.Accepted Author ManuscriptTeam Raf Van de Pla
Online identification of continuous bimodal and trimodal piecewise affine systems
No full textThis paper investigates the identification of continuous piecewise affine systems in state space form with jointly unknown partition and subsystem matrices. The partition of the system is generated by the so-called centers. By representing continuous piecewise affine systems in the max-form and using a recursive Gauss-Newton algorithm for a suitable cost function, we derive adaptive laws to online estimate parameters including both subsystem matrices and centers. The effectiveness of the proposed approach is demonstrated with a numerical example.Accepted Author ManuscriptTeam Bart De Schutte
Integrated dynamic modelling and multivariable control of HVAC components
No full textThe field of energy efficiency in buildings offers challenging opportunities from a control point of view. Heating, Ventilation and Air-Conditioning (HVAC) units in buildings must be accurately controlled so as to ensure the occupants' comfort and reduced energy consumption. While the existing HVAC models consist of only one or a few HVAC components, this work involves the development of a complete HVAC model for one thermal zone. Also, a novel multivariable control strategy based on PI auto-tuning is proposed by combining the aforementioned model with optimization of the desired (time-varying) equilibria. One of the advantages of the proposed PI strategy is the use of time-varying input equilibria and zone setpoint temperature, which can lead to important energy savings. A comparison with a baseline control strategy with constant setpoint temperature is presented: the comparison results show good tracking performance and improved energy efficiency in terms of HVAC energy consumption.Accepted Author ManuscriptOLD Intelligent Control & RoboticsTeam Bart De Schutte
An architecture for implementation of multivariable controllers
Get PDFBrowse > Conferences> American Control Conference, Prev | Back to Results | Next » An architecture for implementation of multivariable controllers 786292 searchabstract Niemann, H. ; Stoustrup, J. ; Dept. of Autom., Tech. Univ., Lyngby This paper appears in: American Control Conference, 1999. Proceedings of the 1999 Issue Date : 1999 Volume : 6 On page(s): 4029 - 4033 vol.6 Location: San Diego, CA Meeting Date : 02 Jun 1999-04 Jun 1999 Print ISBN: 0-7803-4990-3 References Cited: 7 INSPEC Accession Number: 6403075 Digital Object Identifier : 10.1109/ACC.1999.786292 Date of Current Version : 06 august 2002 Abstract An architecture for implementation of multivariable controllers is presented in this paper. The architecture is based on the Youla-Jabr-Bongiorno-Kucera parameterization of all stabilizing controllers. By using this architecture for implementation of multivariable controllers, it is shown how it is possible to change from one multivariable controller to another multivariable controller online in a smooth way with guarantee for closed loop stability. This includes also the case where the controllers are unstable. Gain scheduled controllers can be implemented in this architecture. The general architecture for smooth online changes of multivariable controllers can also handle the start up and close down of multivariable systems. Furthermore, the start up of unstable multivariable controllers can also be handled in this architecture. Finally, implementation of (unstable) controllers as a stable Q parameter in a Q-parameterized controller can also be achieved
Energy Management for Fuel Minimization in Hybrid Fuel Cell All-Electric Aircraft: Modeling, Estimation, and Control of Nonlinear Systems
No full textThis work presents the development and integration of an Energy Management System (EMS) with a propulsioncontroller for an All-Electric Aircraft powered by a fuel cell, a lithium-ion battery, and a supercapacitor. Offlineoptimization identifies the optimal fuel cell current and the optimal cruise velocity, which serve as design targets forreal-time control. The EMS is implemented as a proportional–integral (PI) controller designed to minimize hydrogen consumption while ensuring that the battery and supercapacitor state of charge (SoC) are depleted exactly atthe end of a predefined mission distance. The propulsion PI controller maintains the desired cruise velocityand supplies the propulsion power demand to the EMS. A simplified Matlab model combining the EMS and propulsiondynamics is developed to demonstrate the approach. Simulation results show that the propulsion controller isable to track the aircraft velocity with minimal errors. The EMS on the other hand is not able to efficientlydistribute the current between the three components
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