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US 12,203,785 B2Granted
Measuring system and pressure medium cylinder comprising a measuring system
AssigneeVan Halteren Technologies Boxtel B.V.
InventorLeo Caspers
Life of this patent
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AssigneeVan Halteren Technologies Boxtel B.V.
InventorLeo Caspers
Estimating the term…
The linear measuring system includes one part of a (usually steel) rod, beam or strip that is profiled with a trapezium like (subset of a) De Bruijn sequence. Each element of the alphabet is represented by a discrete height of the profile. The profile can be coated with a material with low magnetic susceptibility to enable the application on a piston rod of a pressure medium cylinder. The second part of the measuring system reads the subsequences of the main sequence by using the signals of arrays of linear Hall effect sensors, placed in a magnetic field as input for a signal processing algorithm. With a look-up table, the position of this second part of the measuring system with respect to the profile is determined. An interpolation algorithm can be used to improve the resolution to well below the sequence pitch.
A measuring system for determining the position of a piston rod of a pressure medium cylinder relative to a reference point, wherein the measuring system has a code track that is applied to the piston rod, runs along the piston rod, and is formed by grooves and plateaus running in the circumferential direction in a base material of the piston rod, and wherein the measuring system has at least a first sensor system that is stationary relative to the reference point and has a plurality of sensor elements that are arranged parallel to and radially spaced apart from the piston rod, and wherein each sensor element scans a limited number of code elements, characterized in that, to form the code track, at least trinary code elements are used, which form a De Bruijn sequence and/or a De Bruijn subsequence.
Dependencies are inferred from the claim text.