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:
Mar. 07, 2006
Filed:
Oct. 24, 2003
Lahoucine Ettaleb, Pointe-Claire, CA;
Alain André Roche, Montréal, CA;
Lahoucine Ettaleb, Pointe-Claire, CA;
Alain André Roche, Montréal, CA;
Pulp and Paper Research Institute of Canada, Pointe-Claire, CA;
Abstract
A method and apparatus to perform an automatic diagnosis for the poor performance of a control loop, and to determine whether or not the malfunctioning is caused principally by a poor adjustment of the controller tuning parameters. The method makes use of the fact that a poorly tuned control loop amplifies disturbances in a narrow frequency range around the so-called resonant frequency. The method comprises measuring an error in a control loop over time to determine a power spectral density of the error, determining a best fit analytical function describing the power spectral density and measuring a diagnostic value from a difference between the best fit analytical function and the power spectral density of the error.