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Control of systems with limited capacity

Solyom, Stefan LU (2004) In PhD Theses TFRT-1069.
Abstract (Swedish)
Popular Abstract in Swedish

Alla regler system kan betraktas som system med begränsad kapacitet. Detta arbetet består av fyra delar. Den första delen betraktar reglering av låsningsfria bromsar (ABS). Den andra delen betraktar en tuning metod för PID regulatorer. Den tredje delen beskriver servoproblemet för styckvislinjära system samt en anti-windup syntes metod. Den sista delen beskriver ett spänningstabiitet problem i elkraftsystem.
Abstract
Virtually all real life systems are such that they present some kind of limitation on one or many of its variables, physical quantities. These systems are designated in this thesis as systems with limited capacity. This work is treating control related problems of a subclass of such systems, where the limitation is a critical factor.



The thesis is composed of four parts. The first part is treating the control of tire slip in a braking car. The Anti-lock Braking System (ABS) is an important component of a complex steering system for the modern car. In the latest generation of brake-by-wire systems, the controllers have to maintain a specified tire slip for each wheel during braking. This thesis proposes a design model and... (More)
Virtually all real life systems are such that they present some kind of limitation on one or many of its variables, physical quantities. These systems are designated in this thesis as systems with limited capacity. This work is treating control related problems of a subclass of such systems, where the limitation is a critical factor.



The thesis is composed of four parts. The first part is treating the control of tire slip in a braking car. The Anti-lock Braking System (ABS) is an important component of a complex steering system for the modern car. In the latest generation of brake-by-wire systems, the controllers have to maintain a specified tire slip for each wheel during braking. This thesis proposes a design model and based on that a hybrid controller that regulates the tire-slip. Simulation and results from drive tests are presented. In the second part, a design method for robust PID controllers is presented for a class of systems with limited capacity. Robustness is ensured with respect to a cone bounded static nonlinearity acting on the plant. Additional constraints on maximum sensitivity are also considered. The design procedure has been successfully applied in the synthesis of the proposed ABS controller. The third part studies the trajectory convergence for a general class of nonlinear systems. The servo problem for piecewise linear systems is presented. Convex optimization is used to describe the behavior of system trajectories of a piecewise linear system with respect to some input signals. The obtained results are then applied for the study of anti-windup compensators. The last part of the thesis is treating the problem of voltage stability in power systems. Voltage at the load end of a power system has to be controlled within prescribed tolerances. In case of emergencies such as sudden line failures, this task ca n be very challenging. The main contribution of this chapter is a method for improving the stability properties of the power system by dynamic compensation of the reference load voltage. Moreover, a complete compensation scheme is proposed where load shedding is the secondary control variable. This control scheme is shown to stabilize different power system models. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Professor Hill, David, Hong Kong
organization
publishing date
type
Thesis
publication status
published
subject
keywords
voltage collapse, power systems, anti-windup, piecewise linear systems, synthesis, ABS, PID control, LMI, Automation, robotics, control engineering, Automatiska system, robotteknik, reglerteknik
in
PhD Theses
volume
TFRT-1069
pages
153 pages
publisher
Department of Automatic Control, Lund Institute of Technology (LTH)
defense location
Lundmarksalen, Astronomihuset, Lund
defense date
2004-08-20 10:15
ISSN
0280-5316
language
English
LU publication?
yes
id
1bf46acc-40d2-4349-8113-a5bf819d66c6 (old id 21799)
date added to LUP
2007-05-28 14:43:27
date last changed
2016-09-19 08:44:58
@phdthesis{1bf46acc-40d2-4349-8113-a5bf819d66c6,
  abstract     = {Virtually all real life systems are such that they present some kind of limitation on one or many of its variables, physical quantities. These systems are designated in this thesis as systems with limited capacity. This work is treating control related problems of a subclass of such systems, where the limitation is a critical factor.<br/><br>
<br/><br>
The thesis is composed of four parts. The first part is treating the control of tire slip in a braking car. The Anti-lock Braking System (ABS) is an important component of a complex steering system for the modern car. In the latest generation of brake-by-wire systems, the controllers have to maintain a specified tire slip for each wheel during braking. This thesis proposes a design model and based on that a hybrid controller that regulates the tire-slip. Simulation and results from drive tests are presented. In the second part, a design method for robust PID controllers is presented for a class of systems with limited capacity. Robustness is ensured with respect to a cone bounded static nonlinearity acting on the plant. Additional constraints on maximum sensitivity are also considered. The design procedure has been successfully applied in the synthesis of the proposed ABS controller. The third part studies the trajectory convergence for a general class of nonlinear systems. The servo problem for piecewise linear systems is presented. Convex optimization is used to describe the behavior of system trajectories of a piecewise linear system with respect to some input signals. The obtained results are then applied for the study of anti-windup compensators. The last part of the thesis is treating the problem of voltage stability in power systems. Voltage at the load end of a power system has to be controlled within prescribed tolerances. In case of emergencies such as sudden line failures, this task ca n be very challenging. The main contribution of this chapter is a method for improving the stability properties of the power system by dynamic compensation of the reference load voltage. Moreover, a complete compensation scheme is proposed where load shedding is the secondary control variable. This control scheme is shown to stabilize different power system models.},
  author       = {Solyom, Stefan},
  issn         = {0280-5316},
  keyword      = {voltage collapse,power systems,anti-windup,piecewise linear systems,synthesis,ABS,PID control,LMI,Automation,robotics,control engineering,Automatiska system,robotteknik,reglerteknik},
  language     = {eng},
  pages        = {153},
  publisher    = {Department of Automatic Control, Lund Institute of Technology (LTH)},
  school       = {Lund University},
  series       = {PhD Theses},
  title        = {Control of systems with limited capacity},
  volume       = {TFRT-1069},
  year         = {2004},
}