Off-campus UMass Amherst users: To download campus access theses, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users: Please talk to your librarian about requesting this thesis through interlibrary loan.
Theses that have an embargo placed on them will not be available to anyone until the embargo expires.
Electrical & Computer Engineering
Master of Science in Electrical and Computer Engineering (M.S.E.C.E.)
Year Degree Awarded
All physically realizable systems are subject to saturations of one form or another. Control systems having saturations are susceptible to the nonlinear problem of reset-windup if the controllers within those systems contain one or more integrators. Reset-windup is a condition whereby the integrator continues to integrate the feedback error and add to the control signal, even in the presence of a decreasing error signal. This phenomenon can lead to excessive overshoot in the system in response to large setpoint changes.
This paper discusses the problem of reset-windup in detail and presents several methods for correcting this problem in continuous-time systems as discussed in existing controls literature. Two approaches to the elimination of reset-windup are discussed in detail: the conventional anti-reset windup (CAW) scheme and the override signal (OS) scheme. The application of these methods to continuous-time systems is reviewed for simple example systems. The paper then proposes implementations of these methods for discrete-time systems, discusses problems associated with these implementations, including the phenomenon of "chatter", and presents design criteria to make these implementations useful. Finally, the practical application of antireset-windup compensation is discussed through the design of a digital controller for an existing system.
Douglas P. Looze