SYSTEM AND METHOD FOR MAGNETICALLY SENSING POSITION OF MOVING COMPONENT

• Main Authors: PABLO GARCIA, DONALD C ARNTZ
• Format: Patent
• Language: English
• Published: 15.12.2011
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

PROBLEM TO BE SOLVED: To provide a piston rod sensing system in which the strength of a rod is not adversely effected and a magnetically encoded signal is not erased.SOLUTION: Information is magnetically recorded in a plurality of tracks in the region of the magnetic hard layer on the piston rod. Magnetic-field sensors are arranged in the tracks in the magnetically recorded region. The magnetic-field sensors arranged on the tracks sense the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. The magnetically recorded information is relatively encoded. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track piston rod movement when the machinery is off.