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:
May. 18, 1999
Filed:
Dec. 29, 1997
Young Il Jin, Changwon, KR;
Jin Han Lee, Changwon, KR;
Abstract
A method for detecting the direction and displacement of a rod member of a hydraulic cylinder assembly is provided. The hydraulic cylinder assembly includes a plurality of magnetic sensors for outputting a magnetic field variation signal disposed adjacent a hydraulic cylinder. The plurality of magnetic sensors cooperate with a plurality of magnetic projections equally spaced along a rod member for producing the magnetic field variation signal. The signal is converted from a sine wave into a square wave by using a microprocessor. The edges of the converted square wave are counted to accurately detect a direction and displacement amount. The method further includes the steps of ignoring a square wave edge caused by disturbance, if the square wave edge occurs prior to a pre-set time, wherein the pre-set time is based on the average time interval for previous edges. The method further includes the step of generating a correction edge when no edge is detected during the pre-set time interval. The method still further includes the step of detecting successive correction edges for determining an absolute position of the hydraulic stroke.