Method and apparatus for wire rope distance measurement
AssigneeNDT Technologies, Inc.
InventorHerbert R. Weischedel
Life of this patent
Estimating the term…
Abstract
Measuring distance along a wire rope, by steps that include moving the wire rope across a sensor head; counting rotations of a rotary encoder driven by the moving wire rope; detecting a first distance marker crossing the sensor head at a first position of the wire rope; detecting a second distance marker crossing the sensor head at a second position of the wire rope; and establishing calibration parameters for producing a calibrated distance measurement corresponding to any output of the rotary encoder, based at least on correlating a known distance between the first and second distance markers to a counted number of pulses of the rotary encoder between the first and second positions of the wire rope.
Claims20
A method for measuring distance along a wire rope, said method comprising:
- moving the wire rope across a sensor head;
- counting pulses of a rotary encoder driven by the moving wire rope;
- detecting a first distance marker crossing the sensor head at a first position of the wire rope;
- detecting a second distance marker crossing the sensor head at a second position of the wire rope;
- and
- establishing calibration parameters for producing a calibrated distance measurement corresponding to an output of the rotary encoder, based at least on correlating a known distance between the first and second distance markers to a counted number of pulses of the rotary encoder between the first and second positions of the wire rope.
An apparatus for measuring distance along a wire rope that travels along a measurement path, said apparatus comprising:
- a first sensor head;
- an incremental rotary encoder that is spaced apart from the first sensor head to define the measurement path, and is disposed to contact a wire rope moving along the measurement path;
- and
- a distance calibrator that is configured to count rotations of the incremental rotary encoder as the wire rope moves along the measurement path, to detect a first distance marker via the first sensor head at a first position of the wire rope along the measurement path, to detect a second distance marker via the first sensor head at a second position of the wire rope along the measurement path, and to establish calibration parameters that correlate the counted rotary encoder pulses between the first and second positions of the wire rope to a known distance between the first and second distance markers.
An apparatus for measuring distance along a wire rope that travels a measurement path, said apparatus comprising:
- first and second magnetic sensor heads disposed along and defining the measurement path;
- an incremental rotary encoder disposed to contact a wire rope that travels along the measurement path;
- first and second magnetizing coils disposed between the first and second sensor heads and spaced apart by a known distance along the measurement path;
- and
- a distance calibrator that is configured to energize the first and second magnetizing coils for inducing respective first and second magnetic markers at an initial position of the wire rope, to detect the first magnetic marker via one of the first or second magnetic sensor heads at a first position of the wire rope, to detect the second magnetic marker via the same one of the first or second magnetic sensor heads at a second position of the wire rope, to count pulses of the incremental rotary encoder as the wire rope moves from the first position to the second position along the measurement path, and to establish calibration parameters that correlate the counted rotations to a known distance between the first and second magnetic markers.
Dependencies are inferred from the claim text.