Buried service detection
AssigneeCable Detection Limited
InventorSimon BRANSON
Life of this patent
Estimating the term…
Abstract
Some embodiments of the invention relate to a mobile detection device for an evaluation of a distance value from the device to an occluded AC-current carrying structure according to its emanated magnetic field, like a location of underground services. The device may include multiple detection coils arranged with a spacing with respect to one another and an electronic signal evaluation unit for detecting the structure according to an electrical signal induced in the detection coils by the magnetic field and to evaluate the distance value according to a difference of the electrical signal in-between at least two of the detection coils.
Claims23
A mobile detection device for an evaluation of a distance/depth value from the device to an occluded AC-current carrying structure according to its emanated magnetic field, with
- a plurality of detection coils, each comprising at least one winding of an electrically conductive material, which are arranged at a fixed location with a spacing with respect to one another;
- and
- an electronic signal evaluation unit for detecting the structure according to an electrical signal induced in the plurality of detection coils by the magnetic field and evaluating the distance value according to a difference of the electrical signal in-between at least two of the plurality of detection coils;
- wherein the the mobile detection device comprises:
- a calibration unit built to configure one of the plurality of detection coils as transmitter for a calibration field by applying an electrical excitation signal, which calibration field is detected by the remaining of the plurality detection coils and
- wherein calibration parameters for the plurality of detection coils are determined by the calibration unit based on the detected calibration field.
A calibration method for a mobile detection device which comprises a plurality of detection coils for an evaluation of a distance value from the detection device to an occluded AC-current carrying structure according to the structures emanated magnetic field, the method comprising:
- applying an electrical excitation signal to one of the plurality of detection coils, which then acts as a magnetic field transmitter for a calibration field;
- receiving and evaluating the calibration field by the remaining detection coil of the plurality of detection coils, which is done multiple times with a permutation of the plurality of detection coils usage for transmitting or receiving;
- and
- determining calibration parameters for at least two of the plurality of detection coils is done by a calibration unit, based on a set of the evaluated calibration fields from each permutation.
A non-transitory computer program product comprising program code stored on a machine-readable medium, or computer-data-signal embodied as an electromagnetic wave, for a calibration of a detection device, built for executing:
- an applying of an excitation signal to one detection coil of the detection device for emanating a calibration field,
- a receiving of the calibration field by at least one other coil of the detection device and storing a field value, wherein the applying and receiving is done alternately for the detection coils of the detection device, preferably to cover all possible permutations, and
- a calculating of calibration parameters for the detection device based on the field values.
Dependencies are inferred from the claim text.