Level radar equipment with adaptive transmission power adjustment

Abstract

The present invention provides a level radar device with adaptive, angle-dependent transmission power regulation, which calculates the maximum allowable transmission power of the transmission signal based on the radiation direction of the transmission signal and the radiation characteristics of an antenna arrangement.

Description

Technical Field

[0001] The present invention relates to a level radar system, and in particular to a level radar device for adaptively adjusting transmission power, a level radar antenna for such a level radar device, a method for adaptively adjusting the transmission power of the level radar device, a program element, and a computer-readable medium. Background Art

[0002] Level radar devices used to determine the level of filling materials or the height or volume of bulk materials use high-frequency electromagnetic signals radiated toward the filling material as transmission signals. These devices typically operate inside containers within factories or outside closed containers installed in open areas.

[0003] The operation of these devices is based on the emission and reception of high-frequency electromagnetic radio signals, which are usually in the frequency bands specified for this purpose in Europe and the United States around 6 GHz, 10 GHz, 24 GHz or between 57 GHz and 64 GHz, or in the range of 75 GHz to 85 GHz.

[0004] In order to "protect" other spectrum users and ensure the coexistence of different radio services, there are various regulatory requirements. In particular, it is important to protect primary radio services from interference, especially those that should be protected from secondary radio services or short-range radio applications (short-range devices (SRD)). Level radar equipment belongs to short-range radio applications. For example, primary radio services are directional radio services for communication and data transmission, broadcasting services, aeronautical radio services or radio astronomy stations. For this purpose, for example, specific installation conditions must be observed for radar level equipment in open areas, and the directivity of the antennas used must also comply with specific standards (see standard EN 302 279 V2.1.1, Chapter 4.6). Summary of the Invention

[0005] An object of the present invention is to provide a level radar device that avoids excessive interference radiation.

[0006] A first aspect of the present invention relates to a level radar device configured for adaptive transmission power regulation. The level radar device includes an antenna assembly configured to radiate a transmission signal toward a filler material or bulk material. A radiation angle determination device is provided to determine the radiation direction of the transmission signal. Furthermore, the level radar device includes a control device configured to adjust the maximum permissible transmission power of the transmission signal based on the radiation direction determined by the device and the radiation characteristics of the antenna assembly.

[0007] Since the maximum transmission power of the device can be changed when the device is tilted or the radiation direction of the transmitted signal changes, the adjustment of the transmission power can be performed adaptively.

[0008] In addition to mechanical tilting of the device, the radiation direction according to embodiments of the present invention can also be varied by electronic beam steering. In this case, an antenna group or array antenna is provided, the individual radiating elements of which are controlled accordingly.

[0009] According to an embodiment of the present invention, the filling level radar device comprises a data memory in which the radiation characteristics of the antenna device and / or calculation rules for calculating the radiation characteristics are stored.

[0010] The data storage device can also be located outside the level radar device, for example, in the cloud or on a server that is in communication with the measuring device. In particular, the necessary calculation of the maximum permissible transmit power of the transmitted signal can be performed outside the measuring device, and the measuring device is then informed only of the final result so that it can adjust the transmit power according to the specified rules.

[0011] According to another embodiment of the present invention, the level radar device comprises a communication interface, wherein the control device is configured to request the radiation characteristic from the external device via the communication interface.

[0012] According to another embodiment of the present invention, the level radar device comprises an identification device configured to identify the antenna device.

[0013] For example, the identification device comprises its own data memory which is mounted on the antenna device and stores identification data of the antenna device.The identification device can be configured to transmit identification data for identifying the antenna device to the control device of the measuring apparatus.

[0014] For example, an RFID chip can be used for this purpose.

[0015] According to another embodiment of the present invention, the radar level measurement device comprises a positioning device configured to determine a position of the level radar device, wherein the control device is configured to adjust the transmission power of the transmission signal based on the position of the level radar device.

[0016] Thus, for example, the measuring device can determine in which country it is located and, based on the result of this determination, determine which regulations regarding the emission of radar signals are currently being complied with.

[0017] According to another embodiment of the present invention, the control device is configured to adjust the transmission power of the transmission signal based on an angle of the radiation direction of the transmission signal relative to the surface of the filling material.

[0018] Thus, for example, it is possible to configure the transmission power to be higher when the main radiation direction of the antenna is oriented perpendicular to the surface of the filling material than when the main radiation direction of the transmitted signal is oriented not perpendicular to the surface of the filling material. In the latter case, a non-negligible portion of the transmitted signal passes through the antenna after reflection from the surface of the filling material.

[0019] According to another embodiment of the present invention, the radiation angle determination device includes a tilt sensor, so that the radiation angle can be determined very efficiently and accurately.

[0020] Another aspect of the present invention relates to a level radar antenna for use in a level radar device as described above and below. The level radar antenna includes a data memory mounted on the level radar antenna and storing identification data for the level radar antenna. The data memory is configured to transmit the identification data, used to identify the level radar antenna, to a control device of the level radar device.

[0021] Another aspect of the present invention relates to a method for adaptively adjusting the transmission power of a level radar device. In this method, a radiation angle determination device determines the radiation direction of a transmission signal from an antenna device. Based on the radiation direction determined in this manner and the radiation characteristics of the antenna device used, a control device adjusts the transmission power of the transmission signal so that the transmission power does not exceed the maximum permissible value under these conditions. The control device can be provided in the level radar device or, at least partially, in an external device. The antenna device is then used to radiate the transmission signal toward the filler material at a transmission power corresponding to the maximum permissible transmission power or less.

[0022] Another aspect of the present invention relates to a program element which, when executed on a control device of the fill level radar device, instructs the fill level radar device to execute the steps described above and below.

[0023] Another aspect of the invention relates to a computer-readable medium, on which a program element as described above is stored.

[0024] For example, the computer program may be loaded or stored in the main memory of a data processing device, such as a data processor, wherein the data processing device may also be part of an embodiment of the present invention. The data processing device may be configured to perform the steps of the above-described method. Furthermore, the data processing device may be configured to automatically execute the computer program or method and / or to process user input. The computer program may also be provided via a data network, such as the Internet, and downloaded from such a data network into the main memory of the data processing device. The computer program may also include an update to an existing computer program, thereby enabling the existing computer program to perform the above-described method, for example.

[0025] The computer-readable storage medium may be, in particular but not necessarily, a non-volatile medium that is particularly suitable for storing and / or distributing computer programs. The computer-readable storage medium may be a CD-ROM, DVD-ROM, optical storage medium, solid-state medium, or the like, which is provided together with or as part of other hardware. Alternatively or additionally, the computer-readable storage medium may also be distributed or distributed in other forms, for example, via a data network such as the Internet or other wired or wireless telecommunications systems. For example, the computer-readable storage medium may be configured as one or more data packets.

[0026] The following describes embodiments of the present invention with reference to the accompanying drawings. The accompanying drawings are schematic and not drawn to scale. If the same reference numerals are used in the following description of the drawings, these reference numerals represent the same or similar elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A measuring arrangement with a fill level radar device is shown.

[0028] Figure 2A A further measuring arrangement with a tilted level radar device is shown.

[0029] Figure 2B A possible dependency of transmit power and tilt angle is shown.

[0030] Figure 3 A level radar device according to an embodiment is shown.

[0031] Figure 4 A level radar device according to another embodiment is shown.

[0032] Figure 5 A level radar device according to another embodiment is shown.

[0033] Figure 6 A level radar device according to another embodiment is shown.

[0034] Figure 7 A flow chart showing a method according to an embodiment is shown. DETAILED DESCRIPTION

[0035] Figure 1 The diagram shows a measurement setup with a fill level radar device 102 for measuring bulk material levels. Many radio receivers receive signals from a low elevation angle relative to the receiving antenna. This is particularly true with terrestrial directional radio services 101, which have an almost horizontal transmission and reception direction, or with mobile radio services.

[0036] The radar level measuring device 102 is usually operated in an open-air location with an antenna orientation pointing vertically downward (plumb). In this orientation, the main radiation direction 103 of the combined transceiver antenna 104 of the level measuring device 102 and the main reception direction 105 of the receiving antenna 106 of the directional radio link 101 are perpendicular to each other.

[0037] In this case, it can be assumed that the signal decoupling of the two radio services is maximum and therefore the influence of the level sensor 102 on the directional radio receiver 106 or the directional radio transmitter 107 is minimal. In this case, for example, the level sensor 102 can only interfere with the directional radio receiver 106 through multipath propagation caused by reflection, diffraction, scattering but resulting in additional signal attenuation or directly through the side lobes of the level radar antenna. In the antenna pattern, the directivity coefficient of the side lobes within the range of about 90° to the main radiation direction is very small compared to the directivity coefficient (Richtfaktoren) of the main radiation direction 103, especially in the case of the level radar antenna 104 with high directivity. Therefore, in both cases, the potential interference at the position of the receiver 106 is significantly reduced. Suitable antenna variants of the level radar device with high directivity are, for example, horn transmitters, waveguide transmitters, antennas with dielectric lenses, parabolic antennas, planar antennas and antenna groups.

[0038] However, in some cases, it may be necessary to pivot the entire radar level sensor with the antenna installed, or only the antenna, or only the main radiation direction of the antenna by a certain angle 206 relative to the vertical direction, so that the echo signal is completely reflected back from the surface of the filling material. Figure 2A This is shown in Figure 1. For example, in the case of a phased antenna array, only the main radiation direction can be pivoted. By adjusting, for example, integrated phase shifters, electronic radiation pivoting can be achieved without changing the mechanical mounting angle of the antenna relative to the vertical.

[0039] In particular, pivoting the entire antenna, or at least the antenna main lobe, is advantageous when measuring non-flat filling material surfaces 201 with a specific deposition angle 202. The level sensor 102 is oriented so that the main radiation direction of the combined transceiver antenna 104 points toward the tip of the material pile and preferably perpendicular to the surface to be measured. If the level sensor were mounted with its main radiation direction pointing vertically downward, most of the signal power would be reflected from the inclined bulk material surface 201 and would no longer return to the level sensor 102. In this case, level measurement would no longer be possible, or only possible with a significantly reduced signal-to-noise ratio, thereby also reducing the measurement certainty.

[0040] However, when the level radar antenna is tilted away from the vertical and / or the main lobe of the electronically pivoted antenna is tilted away from the vertical, the potential interference to other spectrum users and radio services increases again. This is because the level radar now radiates in the horizontal direction 205 via side lobes with a higher directivity coefficient, i.e., the interference level at the external receiver is higher than when the level radar antenna is oriented vertically downward. In this context, it should be noted that in directional antennas commonly used in level radar systems, the directivity coefficient of the side lobes decreases sharply as the angle with the main radiation direction increases.

[0041] By tilting the level radar antenna and / or electronically pivoting the main lobe of the phased antenna array, optimal reflection conditions can be created on the filler material surface, thereby ensuring optimal measurement reliability. Adaptive transmit power regulation is also provided to minimize potential interference with other radio services. The measuring device 102 may include a communication interface 207 through which it exchanges data with an external device 208, such as a server or cloud.

[0042] The possibility of tilting the main radiation direction of the antenna relative to the vertical makes it possible, on the one hand, to ensure optimal reflection conditions, for example when measuring bulk material surfaces with a specific stacking angle 202, i.e., as much of the transmitted signal as possible is reflected back toward the antenna of the level measuring device. On the other hand, in order not to increase potential interference with other spectrum users, the transmission power of the level sensor can be reduced depending on the tilt angle of the main radiation direction relative to the vertical and the radiation characteristics of the antenna used. Thus, in the case of optimal reflection conditions on the filling material surface, reliable measurements with sufficient measurement reliability can be ensured even with reduced transmission power. For example, Figure 2B As shown, the transmission power of the level measuring device can be reduced in multiple stages as the inclination angle of the main radiation direction of the antenna relative to the vertical direction increases.

[0043] Figure 2B The curve is given by the radiation characteristics of the antenna used and the maximum transmission power of the level sensor 102 .

[0044] When the antenna's main radiation direction is oriented vertically downward (0°), it transmits at the highest power P0. Within the angle range from 0° up to the tilt angle α1, the transmitted power drops to the value P1. Within the angle range from α1 up to α2, it drops to the value P2, and so on.

[0045] according to Figure 3In the illustrated embodiment, the electronic or control device 301 of the level radar device 300 includes a power supply 302 for supplying power to all components of the electronic device 301, a control and evaluation device 303, a high-frequency component 304, and an angle determination device 305. For example, the angle determination device may comprise a commercially available electronic tilt sensor, which may be configured with a surface mount technology (SMT) and integrated into the electronic device 301 or directly onto or in the antenna 306. Of course, mechanical or electromagnetic devices are also conceivable, which electronically, inductively, capacitively, or optically detect the position of the antenna 306 relative to the vertical.

[0046] In the case of a phased antenna array, the direction of the main lobe is determined by adjusting the mechanical mounting angle of the integrated phase shifters and the antenna plane relative to the vertical. In this case, the angle determination device preferably comprises a tilt sensor and a calculation rule for determining the main radiation direction relative to the antenna plane from the individual adjustments of the phase shifters.

[0047] A combined transmitting and receiving antenna 306 is connected to the electronics 301. However, separate transmitting and receiving antennas can also be used in this case. The radar sensor 300 is typically installed by a professional and optimally pointed at the filler material surface 201 to be measured. It may be necessary to mechanically tilt the antenna 306 and / or electronically tilt the antenna's main lobe to achieve optimal reflection conditions on the filler material surface. An angle determination device 305 detects the tilt angle of the antenna's main radiation direction relative to the vertical and transmits this value to the control and evaluation device 303. Based on the radiation characteristics of the antenna used (which can be stored in a memory area 307 of the control and evaluation device 303 as a calculated formula or tabular value and stored in the factory during sensor manufacturing), the control and evaluation device 303 determines the maximum possible transmission power in this case to avoid interference with other components of the radio services 106, 107 that may be located nearby and therefore particularly vulnerable to harmful radiation emitted by the radar level sensor.

[0048] The control and evaluation device 303 reports the maximum possible transmission power or any lower transmission power to the high-frequency component 304. For example, the desired transmission power is adjusted at the high-frequency component 304 by appropriately adjusting a variable attenuator or an amplifier with variable gain.

[0049] During the lifecycle of the radar level sensor 102, requirements may change at the measurement location, requiring reconfiguration of the level sensor. To facilitate reconfiguration, the level sensor typically allows the electronics 301 and / or antenna 306 to be replaced and optimally adapted to the new measurement situation. If the antenna 306 and / or electronics 301 are replaced, the correct antenna data must be stored again in the memory 307. Ideally, the appropriate antenna data would already be in the memory 307 and only need to be selected and activated. While an operator can perform this process when reconfiguring the sensor and replacing the antenna and / or electronics, manual intervention carries the risk of incorrect adjustments, as there are often antenna variants that appear identical but have significantly different directional characteristics. In the worst case, such incorrect operation can lead to increased electromagnetic energy radiation from the radar level sensor, which can cause undesirable interference with other radio services.

[0050] To avoid this situation, another exemplary embodiment of a radar level sensor 400 is proposed. Here, an antenna device 402 is equipped with an identification device 403 that allows the antenna to be clearly identified. The identification device 403, which is installed on or in the antenna or in a coupling member belonging to the antenna, includes a data memory 405 and is read by a reader 404 located in the electronic device 401 or transmits identification data to the antenna device. Therefore, the antenna variant used in each case can be clearly identified and the antenna characteristics of the antenna variant can also be clearly identified, and the emission level can be automatically reduced according to the inclination angle of the main radiation direction detected by the angle determination device 305. Preferably, the communication between the identification device 403 and the reader 404 is carried out wirelessly using any radio technology for data transmission (for example, using RFID technology (radio frequency identification)). Of course, other short-range radio technologies such as Bluetooth, ZigBee, WLAN, etc. are also applicable. Similarly, the identification device 403 can be read wired. However, this requires an additional plug connection between the electronic device 401 and the antenna 402.

[0051] If new antenna variants are added during the product life cycle of the radar level sensor or the antenna design is changed which has an impact on the directional characteristics, the correct antenna data may become unavailable in the memory 307 of the sensors 300 and 400 installed at the measuring location, and the correct antenna data must be stored in the memory again after the antenna is correspondingly replaced at the measuring location. This is only possible with external access (e.g. via a wired or wireless communication connection) and requires a service call, which experience has shown requires considerable effort. In order to remedy this, Figure 5 Another exemplary embodiment is presented in .

[0052] In this embodiment, the antenna data is stored in a database 503, which can be located anywhere. The data in the memory 504 can be accessed and updated at any time without the need for expensive service calls. When replacing the antenna 402 on the radar level sensor 500, as previously described, Figure 4 In the exemplary embodiment shown, a new antenna is first automatically identified. The correct antenna data is then transmitted, for example wirelessly, from a database to the level sensor. Using the antenna data and the inclination of the antenna main lobe relative to the vertical, as determined by the angle determination device 305 , the control and evaluation device 303 determines the maximum possible transmission power for this situation and adjusts this transmission power or an arbitrarily lower transmission power in the high-frequency component 304 . The current antenna data is preferably requested from the level sensor 500 via a wireless communication connection to the level sensor 500 and the corresponding transmitting and receiving devices 502 , 505 in the database 503 . A cellular connection is suitable, for example.

[0053] In order to improve the coordination with other radio services (especially primary radio services) and thus make full use of the limited radio spectrum, another exemplary embodiment is proposed. Figures 3 to 5 The radar level sensor 600 of any one of the exemplary embodiments of the present invention further comprises a positioning device 601 (e.g. GPS, GLONASS, Galileo, mobile radio) and a radio interface 602. The level sensor determines its own precise position on the surface of the earth via the positioning device 601 and transmits the position to a central server 603 via wireless communication interfaces 602, 605. The central server comprises a database 604 comprising position data of all radio services that should be protected from harmful radiation from the level sensor. For example, the position data are position data of the transmitter 107 and the receiver 106 of the primary and / or secondary radio services. Figures 3 to 5 As shown in the exemplary embodiment in , if the radar level sensor is located near such a radio service, the transmission power is reduced according to the inclination angle and antenna characteristics. If there are no transmitters or receivers of the radio service to be protected within the range of the level sensor, the transmission power is not reduced during the level measurement. This method is particularly advantageous if regulatory agencies allocate spectrum in the future and add new radio services installed near the radar level sensor. However, to do this, the level sensor 600 needs to regularly check the database 604 with the location data of the radio service to be protected via the wireless interfaces 602 and 605.

[0054] The key feature of the present invention is the introduction of adaptive transmit power control in the radar level sensor, based on the antenna's main radiation direction relative to the plumb bob and the radiation characteristics of the antenna in use. This control determines the maximum compatible transmit power in this situation and adjusts the actual transmit power used to a value less than or equal to the maximum compatible transmit power without increasing the noise level at the locations of other spectrum users. To this end, an angle determination device is integrated into the level measuring device to detect deviations of the antenna's main radiation direction from the plumb bob. Furthermore, access to the radiation characteristics of the antenna in use is essential.

[0055] Figure 7 A flow chart of a method according to one embodiment is shown. In step 701, the radiation direction of the transmitted signal of the antenna device is determined, for example, using a radiation angle determination device integrated into the level measuring device. In step 702, the control device retrieves data describing the radiation characteristics of the antenna device from a memory. Alternatively or additionally, the control device calculates the radiation characteristics of the antenna device using a calculation rule. In step 703, the maximum permissible transmission power of the transmitted signal is then calculated based on the radiation direction and the radiation characteristics, and in step 704, the transmission power is adjusted so that it at most corresponds to the maximum permissible transmission power.

[0056] In addition, it should be noted that "comprising" and "having" do not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. It should also be noted that features or steps described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims should not be considered as limitations.

[0057] CROSS-REFERENCE TO RELATED APPLICATIONS

[0058] The disclosures in European Patent Application No. 19 173 513.3 from which this application claims priority are incorporated herein by reference in their entirety.

Claims

1. A level radar device configured for adaptive transmission power adjustment, comprising: an antenna device configured to radiate a transmission signal toward the filler material; a radiation angle determining device, configured to determine a main radiation direction of the transmitted signal; A control device is configured to reduce the transmission power of the transmission signal in response to an increase in the inclination angle of the main radiation direction relative to the vertical direction and the radiation characteristics of the antenna device so as not to increase potential interference with other radio services.

2. The level radar device according to claim 1, further comprising: A data memory in which the radiation characteristic of the antenna arrangement or a calculation rule for calculating the radiation characteristic is stored.

3. The level radar device according to claim 1 or 2, further comprising: Communication interface, The control device is configured to request the radiation characteristic from an external device through the communication interface.

4. The level radar device according to claim 1 or 2, further comprising: An identification device is configured to identify the antenna device.

5. The level radar device according to claim 4, in, The identification device includes a data memory, which is mounted on the antenna device and stores identification data of the antenna device; The identification device is configured to transmit the identification data for identifying the antenna device to the control device.

6. The level radar device according to claim 1 or 2, further comprising: a positioning device configured to determine a position of the level radar device; The control device is configured to adjust the maximum transmission power of the transmission signal based on the position of the level radar device.

7. The level radar device according to claim 1 or 2, in, The control device is configured to adjust the maximum transmission power of the transmission signal based on an angle of the main radiation direction of the transmission signal relative to the surface of the filling material.

8. The level radar device according to claim 1 or 2, in, The radiation angle determination device includes a tilt sensor.

9. A level radar antenna for a level radar device according to any one of claims 1 to 8, comprising: a data storage device mounted on the level radar antenna and storing identification data of the level radar antenna; The data storage device is configured to transmit the identification data for identifying the filling level radar antenna to the control device of the filling level radar apparatus.

10. A method for adaptively adjusting the transmission power of a level radar device, comprising the following steps: Determining the main radiation direction of the transmitted signal of the antenna device by the radiation angle determination device; reducing, by a control device, the transmission power of the transmission signal in response to an increase in the inclination angle of the main radiation direction relative to the vertical direction and the radiation characteristics of the antenna device so as not to increase potential interference with other radio services; Using the antenna device, the transmission signal is radiated toward the filling material at a transmission power of at most a maximum allowed transmission power.

11. A computer-readable medium having a program element stored thereon, wherein when the program element is executed on a control device of a level radar device, the program element instructs the level radar device to execute the following steps: Determining the main radiation direction of the transmitted signal of the antenna device by the radiation angle determination device; reducing, by a control device, the transmission power of the transmission signal in response to an increase in the inclination angle of the main radiation direction relative to the vertical direction and the radiation characteristics of the antenna device so as not to increase potential interference with other radio services; Using the antenna device, the transmission signal is radiated toward the filling material at a transmission power of at most a maximum allowed transmission power.

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