TOPOLOGY DETERMINATION OF A FILLING MATERIAL SURFACE WITH UNIFORM LINE SCANNING

Abstract

A fill level measurement device for determining a topology of a filling material surface is provided, including an antenna apparatus including an array of radiator elements and a rotatable mount configured to rotate the antenna apparatus about an axis that is in parallel with the array, such that a plurality of emission angles of the antenna apparatus are electronically and mechanically settable relative to the filling material surface without local overscanning occurring.

Claims

1.-12. (canceled)

13. A fill level measurement device for determining a topology of a filling material surface, comprising: an antenna apparatus comprising an array of radiator elements configured to transmit and/or receive electromagnetic signals; and a first rotatable mount configured to rotate the antenna apparatus about a non-vertical axis, wherein the device is configured to electronically and mechanically set a plurality of emission angles and/or receiving angles of the antenna apparatus relative to the filling material surface.

14. The fill level measurement device according to claim 13, wherein the non-vertical axis is in parallel with the array.

15. The fill level measurement device according to claim 13, wherein the array is a unidimensional array that extends in a longitudinal direction, and wherein the axis is in parallel with the longitudinal direction.

16. The fill level measurement device according to claim 13, wherein the device is further configured to set the plurality of emission angles and/or receiving angles electronically by digital beam-forming processes.

17. The fill level measurement device according to claim 13, wherein the device is further configured to set the plurality of emission angles and/or receiving angles electronically by analogue phase shifters and/or by analogue switches.

18. The fill level measurement device according to claim 13, further comprising an additional rotatable mount configured to rotate the antenna apparatus about a shaft that is not in parallel with the array.

19. The fill level measurement device according to claim 18, wherein the additional shaft is a vertical shaft.

20. The fill level measurement device according to claim 13, wherein the antenna apparatus is inclined in a longitudinal extension direction thereof relative to a horizontal direction, such that an angle between the longitudinal extension direction of the antenna apparatus and the horizontal direction is not equal to 0°.

21. The fill level measurement device according to claim 13, further comprising a power supply and a communications interface configured to connect the fill level measurement device to a two-wire line, by which interface the fill level measurement device is supplied with power for measurement operation and by which measured data is transmittable to a remote control unit.

22. A method for determining a topology of a filling material surface, comprising: providing a fill level measurement device; electronically and mechanically setting a first emission angle of an antenna apparatus of the fill level measurement device, the antenna apparatus comprising an array of radiator elements configured to transmit and/or receive electromagnetic signals; detecting an echo curve at the first emission angle; rotating the antenna apparatus about a non-vertical axis in parallel with the array; detecting another echo curve at a second emission angle; and determining the topology of the filling material surface by recording the echo curve and the another echo curve when the first emission angle and the second emission angle are different.

23. The method according to claim 22, further comprising determining, by the fill level measurement device, a viscosity of a moving liquid.

24. The method according to claim 22, further comprising determining, by the fill level measurement device, a mass or a volume of a medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1A shows a fill level measurement device according to an embodiment of the invention that is installed in a container.

[0029] FIG. 1B shows a scan pattern that can be achieved by rotating the antenna apparatus about a vertical (second) axis and by means of electronic beam control.

[0030] FIG. 2 shows an example of a unidimensional array antenna.

[0031] FIG. 3A shows a fill level measurement device in a container according to another embodiment of the invention.

[0032] FIG. 3B shows a scan pattern that can be achieved by rotating the antenna about an axis that is in parallel with the array of the antenna.

[0033] FIG. 4A shows a unidimensional array antenna according to an embodiment of the invention comprising a parabolic trough as the main reflector and a hyperbolically formed counter reflector.

[0034] FIG. 4B is a side view of the antenna from FIG. 4A.

[0035] FIG. 5A shows an antenna apparatus according to an embodiment of the invention.

[0036] FIG. 5B shows the antenna apparatus from FIG. 5A after the antenna apparatus has rotated about the (first) axis.

[0037] FIG. 6 shows a flow diagram of a method according to an embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0038] The views in the drawings are schematic and not to scale. When, in various figures, the same reference signs are used, they identify identical or corresponding elements. However, identical or corresponding elements may also be denoted by different reference signs.

[0039] FIG. 1 shows a fill level measurement device 100 for determining a topology of a surface 101 of a filling material or bulk material 110. The fill level measurement device 100 is attached to the container 111 and comprises an antenna apparatus 102 that can rotate about the axis 121 by means of a rotatable mount. This axis 121 is in parallel with the longitudinal extension of the antenna assembly 102. The rotational direction about the axis 121 is indicated by the arrow 120.

[0040] The antenna apparatus 102 is for example designed as a (unidimensional or two-dimensional) array antenna and has a main emission direction 104 that is typically perpendicular to the plane of the array. The emission direction 104 and in particular the angle β 117 formed between the emission direction 104 and the rotational axis 121 can be set by electronic beam control.

[0041] The antenna apparatus transmits an electromagnetic transmission signal 112, which is reflected by the filling material surface 101 and is radiated back to the antenna apparatus 102. The antenna apparatus receives the signal that is radiated back, and the high-frequency and electronics unit connected thereto forms an echo curve therefrom.

[0042] The fill level measurement device comprises an additional rotatable mount 103, by means of which the antenna apparatus 102 is connected to the main body 116 of the fill level measurement device and by means of which the antenna apparatus 102 can be rotated about the vertical axis, as indicated by the arrow 118.

[0043] The direction of the vertical axis is denoted by reference numeral 123 and the horizontal direction by reference numeral 122.

[0044] The fill level measurement device makes it possible to carry out a rapid and comparatively cost-effective method for detecting a topology of the filling material surface 101, since the main emission direction 104 of the fill level measurement device 100 is not changed purely mechanically or purely electronically, but instead this is carried out by a combined mechanical and electronic change in direction. For example, an electronic line scanner (antenna apparatus 102) is used that can be steered mechanically about the vertical (second) rotational axis and also about the (first) rotational axis 121.

[0045] According to FIG. 2, the line scanner 102 consists of a transceiver unit 201, which may consist of m (m=2, 3, 4, etc.) transmitting and/or receiving antenna elements (also referred to as radiator elements or patches) 202 arranged beside one another in a line. In this case, the y axis 203 extends along the longitudinal extension of the antenna apparatus, and the x axis 204 extends perpendicularly thereto within the plane of the antenna apparatus.

[0046] By electronically processing the individual signals from the transceiver units, the antenna characteristics of this line can be digitally influenced such that the main receiving direction can be steered in one dimension. A line has a narrow antenna opening angle in the y direction of 3 degrees, for example. Appropriate methods for beam steering are known to a person skilled in the art and are described in detail in the technical literature under the keywords “antenna array” and “digital beam forming”.

[0047] The unidimensional antenna 201 can achieve very effective focusing of the resulting antenna characteristics in the direction of the Y extension 203 by using the subsequent algorithms for digital beam forming.

[0048] The rotational axis on which the line scanner is positioned extends in the vertical direction, i.e. in parallel with the surface normal of the container cover 106 (cf. FIG. 1A). The line scanner, which is attached to the rotatable shaft 103 at an angle 107, for example 45 degrees to the container cover, can scan a line 108 of the filling material surface 101 from the cross section of the container 109 by means of mechanical rotation and electronic beam forming (cf. FIG. 1B). In addition to a round cross section, the container may also have a polygonal cross section, or may be any other shape.

[0049] Using this angular position, a scanning pattern according to FIG. 1B is achieved. However, this pattern has the drawback that the scanning density depends on the distance from the centre. While the scanning density is highest in the centre, the density of scanned points decreases towards the edge.

[0050] FIG. 3A shows an antenna apparatus 102 arranged such that it can be used as a line scanner. Here, the individual antenna elements may be in a wide range of forms. For example, the antenna apparatus may be constructed as an array formed by horn radiators, patch antennas or planar Yagi antennas.

[0051] Alternatively or in addition to the vertical rotary shaft 103, as shown in FIG. 1A, a rotational axis 121 is provided that is arranged in parallel with the plane of the antenna assembly 102. In this way, a different scan pattern can be achieved, for example that which is shown in FIG. 3B, or a combination of the scan patterns from FIG. 1B and 3B.

[0052] By combining mechanical and electronic beam steering, a topology can be detected in a cost-effective and time-optimised manner. Unevenly distributed point scanning can be prevented by a rotatably mounted axis 121 that is not in parallel with the surface normal of the container cover, but is preferably perpendicular thereto (cf. FIG. 3A) or, as in the embodiment in FIG. 1A, inclined relative thereto. For example, this axis extends in parallel with the longitudinal extension 203 of the array antenna (see FIG. 2).

[0053] Here, the antenna line can scan a pattern, as shown in FIG. 3B, by means of a clockwise and anticlockwise movement. In this case, the mechanical steering of the line scanner is carried out in the y direction and the electronic steering in the x direction. The individual scan lines 301 thus no longer have any points of intersection and result in a scan pattern having parallel lines in the cross section 302 of the container, and this leads to a shorter scanning time for topology detection.

[0054] Another possibility involves continuously rotating the antenna apparatus 102 about the axis 121. An advantage of the constant and uniform rotation is a lower mechanical load on the steered components.

[0055] FIG. 4A and 4B show another embodiment of an antenna apparatus 102, of which the line scanner consists of a parabolic trough 401 as the main reflector and a hyperbolic rail 402 as the counter reflector. The individual antenna elements 202 are formed by horn radiators, patch antennas or Yagi antennas, for example. The parabolic trough improves the focus of the antenna characteristics in the x direction 204, and this can lead to a higher local resolution of the scanned topology.

[0056] In this case, the transmission signal 403 is emitted by the antenna elements 202 in the direction of the counter reflector 402 and is reflected thereby, and is then reflected again by the surface of the parabolic trough 401.

[0057] The parabolic trough 401 may also be designed without a counter reflector 402, the power-supply elements 202 being positioned in the focal point of the parabolic trough in this case and the parabolic trough rotating about the power-supply elements, as shown in FIG. 5A and 5B by the arrow 501. In this embodiment, the inner surface is parabolically formed and coated with metal in the region of the shaded area of the trough 401. The outer cross section may be circular, however. Advantageously, the steered components do not contain electrical components, and this means that the number of sliding contacts that are susceptible to wear can be reduced.

[0058] In order to protect against dust and deposit build-up, a radome 502 in the form of a cylindrical roller can be used that surrounds the respective antenna elements and is connected to the mechanically rotated components. A piece of mechanical equipment 503 may be provided, for example in the form of a plate or brush, which is used to remove deposit build-ups from the radome. The radome is transparent to the emitted and received high-frequency energy 504.

[0059] The antenna apparatus 102 is fastened to the housing of the fill level measurement device by means of two suspension means 505, 506. The two suspension means do not have to be in parallel.

[0060] FIG. 5B shows the antenna apparatus from FIG. 5A, with the parabolic trough being rotated anticlockwise by approximately 20 degrees.

[0061] FIG. 6 is a flow diagram of a method according to an embodiment of the invention. In step 601, a fill level measurement device is provided that is fastened to a container. In step 602, a first emission angle of an antenna apparatus of the fill level measurement device is electronically and mechanically set, following which an echo curve is detected at the first emission angle in step 603. In step 604, the antenna apparatus is then rotated about an axis which is in parallel with the array of the antenna apparatus. In step 605, another echo curve is recorded at a second emission angle. The topology of the filling material surface can be determined from echo curves of this type that are recorded at different emission angles.

[0062] It should additionally be pointed out that “comprising” does not exclude the possibility of further elements or steps, and “a”, “an” or “one” does not exclude the possibility of a plurality. It should further be noted that features or steps which have been described with reference to one of the above embodiments may also be used in combination with other features or steps of other above-described embodiments. Reference signs in the claims shall not be deemed to have a limiting effect.