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KR-102963470-B1 - Device and method for determining dimensional data relating to an object

KR102963470B1KR 102963470 B1KR102963470 B1KR 102963470B1KR-102963470-B1

Abstract

The present invention relates to a method for determining dimensional data, particularly thickness data, related to a plate-shaped object or a strand-shaped object, in particular a pipe, wherein the method comprises: - A step of emitting terahertz radiation by a first transmitter to one or more locations on the surface of an object at one or more times; - Includes the step of receiving the terahertz radiation emitted from the first transmitter by the first receiver after the radiation has passed through an object one or more times, and - A step of emitting terahertz radiation having a bandwidth of less than 5% of the carrier frequency of the terahertz radiation by a second transmitter at multiple times the surface of an object and/or multiple locations on the surface of the object; - A step of receiving the terahertz radiation emitted from the second transmitter by the second receiver after the radiation has passed through an object one or more times; and - Further includes the step of determining the dimensions of an object from the terahertz radiation received by the second receiver, and/or from the temporal and/or spatial variation of the terahertz radiation received by the second receiver in consideration of the terahertz radiation received by the first receiver. In addition, the present invention relates to a device for determining dimensional data related to a plate-shaped or strand-shaped object.

Inventors

  • 콜야 토비아스 슈
  • 힐마르 볼테

Assignees

  • 시코라 게엠베하

Dates

Publication Date
20260512
Application Date
20230307
Priority Date
20220309

Claims (20)

  1. A method for determining dimensional data related to a plate-shaped object (34) or a strand-shaped object (18), - A step of emitting terahertz radiation by a first transmitter (10) to one or more locations on the surface of an object (18, 34) at one or more times; and - A method comprising the step of receiving the radiation by the first receiver (10) after the terahertz radiation emitted from the first transmitter (10) has passed through the object (18, 34) at least once, - A step of emitting terahertz radiation having a bandwidth of less than 5% of the carrier frequency of the terahertz radiation by the second transmitter (12) at multiple times to multiple locations on the surface of the object and/or on the surface of the object (18, 34); - A step of receiving the radiation by the second receiver (12) after the terahertz radiation emitted from the second transmitter (12) has passed through the object (18, 34) at least once; and - Further includes the step of determining the dimensions of an object (18, 34) from the terahertz radiation received by the second receiver (12), and/or from the temporal and/or spatial variation of the terahertz radiation received by the second receiver (12) in consideration of the terahertz radiation received by the first receiver (10), and A method characterized in that the bandwidth of the terahertz radiation emitted from the first transmitter (10) is greater than 10% of the carrier frequency of the terahertz radiation.
  2. delete
  3. A method according to claim 1, characterized in that the bandwidth of the terahertz radiation emitted from the second transmitter (12) is less than 3% of the carrier frequency of the terahertz radiation.
  4. A method according to claim 1, wherein the first transmitter (10) and the first receiver (10) are formed by the first transmitter/receiver (10), and/or the second transmitter (12) and the second receiver (12) are formed by the second transmitter/receiver (12).
  5. A method according to any one of claim 1, 3, or 4, wherein a first reflector (22) for terahertz radiation emitted from a first transmitter (10) is arranged on one side of an object (18, 34) opposite the first transmitter (10), and/or a second reflector (24) for terahertz radiation emitted from a second transmitter (12) is arranged on one side of an object (18, 34) opposite the second transmitter (12).
  6. A method according to any one of claim 1, 3, or 4, wherein the second transmitter (12) and the second receiver (12) rotate around the object (18, 34) and/or are transposed along the object (18, 34), and/or a plurality of second transmitters (12) and second receivers (12) are arranged around the object (18, 34) or along the object (18, 34).
  7. A method according to any one of claim 1, 3, or 4, characterized in that the second transmitter (12) emits terahertz radiation onto the surface of an object (18, 34) at an inclined angle of incidence.
  8. A method characterized in that, in any one of claim 1, 3, or 4, the dimensions of the object (18, 34) are determined by taking into account the refractive index of the object (18, 34).
  9. A method according to claim 8, characterized in that the refractive index of an object (18, 34) is determined from terahertz radiation received by a first receiver (10).
  10. A method according to any one of claim 1, 3, or 4, characterized in that the dimensions of the object are determined from the phase change of terahertz radiation emitted from the first and/or second transmitter (10, 12) caused while the radiation passes through the object (18, 34).
  11. A method characterized in that, in any one of claim 1, 3, or 4, the defect of the object (18, 34) is inferred based on the rapid signal change of the terahertz radiation signal received by the second receiver (12).
  12. A device for determining dimensional data related to a plate-shaped or strand-shaped object (18, 34), - A first transmitter (10) that emits terahertz radiation at one or more locations on the surface of an object (18, 34) at one or more times; and - A device comprising a first receiver (10) that receives terahertz radiation emitted from a first transmitter (10) after the radiation has passed through an object (18, 34) at least once, - A second transmitter (12) that emits terahertz radiation having a bandwidth of less than 5% of the carrier frequency of the terahertz radiation at multiple times on the surface of an object and/or at multiple locations on the surface of the object (18, 34); - A second receiver (12) that receives the terahertz radiation emitted from the second transmitter (12) after it has passed through the object (18, 34) at least once; and - Further includes an evaluation device (26) for determining the dimensions of an object (18, 34) from terahertz radiation received by the second receiver (12), and/or from temporal and/or spatial variation of terahertz radiation received by the second receiver (12) in consideration of terahertz radiation received by the first receiver (10), and A device characterized in that the bandwidth of the terahertz radiation emitted from the first transmitter (10) is greater than 10% of the carrier frequency of the terahertz radiation.
  13. delete
  14. A device according to claim 12, characterized in that the bandwidth of the terahertz radiation emitted from the second transmitter (12) is less than 3% of the carrier frequency of the terahertz radiation. Radioactivity.
  15. An apparatus according to claim 12, characterized in that the first transmitter (10) and the first receiver (10) are formed by the first transmitter/receiver (10), and/or the second transmitter (12) and the second receiver (12) are formed by the second transmitter/receiver (12).
  16. An apparatus characterized in that, in any one of claim 12, 14, or 15, a first reflector (22) for terahertz radiation emitted from a first transmitter (10) is arranged on one side of an object (18, 34) opposite the first transmitter (10), and/or a second reflector (24) for terahertz radiation emitted from a second transmitter (12) is arranged on one side of an object (18, 34) opposite the second transmitter (12).
  17. An apparatus characterized in that, in any one of claim 12, 14, or 15, a rotation and/or transverse device is provided for rotating the second transmitter (12) and the second receiver (12) around the object (18, 34) during measurement and/or transposing the second transmitter (12) and the second receiver (12) along the object (18, 34) during measurement, and/or a plurality of second transmitters (12) and second receivers (12) are arranged around the object (18, 34) or along the object (18, 34).
  18. A device according to any one of claim 12, 14, or 15, characterized in that the second transmitter (12) is arranged to emit terahertz radiation onto the surface of an object (18, 34) at an inclined angle of incidence.
  19. A device characterized in that, in any one of claim 12, 14, or 15, the evaluation device (26) additionally determines the dimensions of the object (18, 34) by taking into account the refractive index of the object (18, 34).
  20. In claim 19, the evaluation device (26) is further characterized by determining the refractive index of an object (18, 34) from terahertz radiation received by the first receiver (10).

Description

Device and method for determining dimensional data relating to an object The present invention relates to a method for determining dimensional data, particularly thickness data, associated with a plate-shaped object or a strand-shaped object, particularly a pipe, the method comprising the steps of: emitting terahertz radiation by a first transmitter to one or more locations on the surface of an object at one or more times; and receiving the radiation by a first receiver after the terahertz radiation emitted from the first transmitter has passed through the object one or more times. In addition, the present invention relates to a device for determining dimensional data associated with a plate-shaped or strand-shaped object, the device comprising a first transmitter designed to emit terahertz radiation to one or more locations on the surface of an object at one or more times, and a first receiver designed to receive the radiation after the terahertz radiation emitted from the first transmitter has passed through the object one or more times. For example, dimensional data related to plate-shaped or strand-shaped objects, such as pipes, can be measured using terahertz radiation, also known as millimeter waves. Such dimensional data includes, for instance, diameter or thickness, particularly wall thickness. Terahertz radiation signals are emitted by a transmitter toward the object to be measured. The emitted radiation signals pass through the object and are then reflected from the object's boundary surfaces. Subsequently, the terahertz radiation is received by a receiver. Due to the object, the radiation signal is manipulated by reflection, scattering, absorption, and refraction. The resulting changes in the terahertz radiation signal allow for the derivation of conclusions about the object to determine dimensional data, and specifically enable the evaluation of reflection at the object's boundary layer. Furthermore, the object delays the terahertz radiation signal due to its higher density relative to propagation in the air. Therefore, by measuring the delay of the radiation signal, and knowing the object's orientation and refractive index, the absolute value of the object's dimensions can be determined. This applies particularly to plate-shaped or strand-shaped objects, such as pipes. However, to evaluate reflections at the boundary layer of an object, the bandwidth of the terahertz radiation used is required to allow for the resolution of individual boundary layers. When the dimensions to be measured are small, such as low wall thicknesses, strict requirements exist regarding the bandwidth of the terahertz radiation used. The required bandwidth is approximately equal to twice the product of the speed of light, the refractive index, and the distance to the structure being analyzed, for example, the boundary surface being analyzed. Depending on the size of the structure, this may require a bandwidth in the 100 GHz range. This makes the terahertz transmitters and receivers required to reliably measure small structures complex and more expensive. Additionally, special approval procedures are often required. Costs increase if these types of transmitters and receivers are arranged, for example, around the pipe being measured. This is often desirable only when the goal is to irradiate the object to measure it as perfectly as possible. Another problem arises from disturbances in the geometric structure, particularly defects such as bubbles, concave grooves, and protrusions. To detect defects, DE 10 2016 105 599 A1 proposes radiating terahertz radiation onto the boundary surface of the object to be measured at a non-vertical angle, so that reflections from the test object and reflections toward the transmitter and receiver occur only at the defects of the object. Alternatively, to exclude reflections caused by the boundary surface of the object from the measurement, the main reflected radiation may be suppressed by an aperture. DE 20 2021 100 416 U1 proposes an evaluation device for detecting defects in strand-shaped products transported along a transport direction, and the evaluation device is designed to infer defects in strand-shaped products from transient changes in terahertz radiation signals received by one or more receivers. FIG. 1 illustrates an apparatus according to the present invention for performing the method according to the present invention in a first application scenario. Figure 2 illustrates the device of Figure 1 in a second application scenario. FIG. 3 illustrates a graph for showing defect detection according to the present invention. Unless otherwise specified, the same reference numeral in a drawing represents the same object. The device illustrated in FIG. 1 includes a first transmitter (10) for emitting terahertz radiation and a first receiver (10) for receiving terahertz radiation emitted from the first transmitter (10). Additionally, the device also includes a second transmitter (12) for e