The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 10, 1996
Filed:
Nov. 10, 1994
Edwin M Heaven, North Vancouver, CA;
Christopher B Lynch, Burnaby, CA;
Par O Hallman, North Vancouver, CA;
Measurex Devron Inc., North Vancouver, CA;
Abstract
A caliper profile control system for a paper machine provides reduced start up times after sheet breaks to bring the caliper profile across the sheet to within the desired limits. The method comprises the steps of scanning at predetermined intervals across the width of the paper sheet to monitor thickness error of the sheet from predetermined limits and change in the thickness error between the intervals, in each of a plurality of zones across the sheet. A control change signal is determined for each of the zones based on the error and the change in error using an exponential function of the magnitude of the error to maximize the change in the error and reduce integral action when the error is large. The control signal is used to reduce the error in each zone and the integral action is increased as the error decreases until the predetermined limits are met.