The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
Aalto

Fault Diagnostics and Vibration Control of Paper Winders

Timo Virtanen

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Automation and Systems Technology for public examination and debate in Auditorium AS1 at Helsinki University of Technology (Espoo, Finland) on the 2nd of December, 2006, at 12 noon.

Dissertation in PDF format (ISBN 951-22-8468-5)   [5968 KB]
Dissertation is also available in print (ISBN 951-22-8467-7)

Abstract

A Level-to-Level Minimization (LLM) algorithm based on Boolean algebra was developed and compared to the Quine-McCluskey algorithm based on the manipulation of truth tables of logic functions. The minimization with Boolean laws can save much computing time and memory with certain types of logic functions when compared to the methods based on truth tables. A Multilevel Product-Of-Sums net model is introduced as well. A practical example demonstrates the use of the methods in the paper winders.

Two different case studies of model-based fault diagnostics are introduced. The first deals with tension control of a paper web and the latter the hydraulic force control of a rider roll. A very detailed simulation model of a rider roll is used to examine the effects of various types of faults in a hydraulic system.

The theories of the delayed resonators and active resonator absorbers were further developed. The new methods make it possible to control both resonance frequency and damping factor. A cascade-controlled delayed resonator was also developed to broaden the operating range of actively controlled mass dampers. Stability issues were considered as well. An active damping application based on a hydraulic actuator was also developed. This method was tested with a full-scale pilot winder.

Keywords: fault diagnostics, vibration control, paper winding, PLC, Boolean algebra

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© 2006 Helsinki University of Technology

Last update 2011-05-26