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:
Feb. 24, 2004
Filed:
Sep. 04, 2002
Kari Saarinen, Kaarnatie, FI;
Michal Orkisz, Ul. Zakatek, PL;
ABB Research Ltd., Zurich, CH;
Abstract
The present invention relates to a method of determining speed of rotation of a motor. The method involves collecting samples with a measuring sensor at a sampling frequency, set on the basis of mechanical vibration of the motor, for the duration of a measurement period and storing the samples in the memory of a data carrier as measurement data of a fixed format. The speed of rotation of the motor is determined from the measurement data by determining the cycle length of a periodic vibration signal in the time domain by means of a maximum likelihood estimate calculated by maximizing a maximum likelihood function adjusted to the measurement data, the speed of rotation being obtained from the frequency point where the maximum likelihood function obtains its maximum value.