radar device

Abstract

Radar device (10) with - an antenna array (12) comprising at least a first antenna (14) and a second antenna (16), - at least a first transceiver (18) and a second transceiver (20) where Both the first transceiver (18) and the second transceiver (20) are in signal contact with the first antenna (14) and the second antenna (16).

Description

[0001] The present invention relates to a radar device with an antenna array comprising at least a first antenna and a second antenna.

[0002] Such radar systems are used in various mobile and stationary applications to detect objects such as obstacles, people, items, and the like. For example, an autonomous guided vehicle (AGV) used in automated processes in factory halls or warehouses can be equipped with such a radar system to detect and avoid obstacles. The radar system can determine the distance, direction, and / or size of the obstacle. A transceiver controls the antenna array to transmit radio waves, for example, in a directed manner, and to detect radio waves reflected back from objects.

[0003] For autonomous vehicles and other applications, safety-related sensors may be required that enable reliable self-monitoring. Such safety sensors typically require hardware redundancy to reliably detect fault conditions.

[0004] Modern radar systems often use pre-built transceivers (i.e., transmitter-receivers) that lack redundancy. While doubling both the transceiver and the antenna array would create the redundancy required for safety-related applications, this would result in a much larger radar system.

[0005] The object underlying the invention is therefore to provide a radar device which can be used in safety-related applications, but can still be designed to be compact.

[0006] This problem is solved by a radar device according to claim 1.

[0007] The radar device according to the invention comprises an antenna array having at least a first antenna and a second antenna. The radar device also comprises at least a first transceiver and a second transceiver. Both the first transceiver and the second transceiver are in signal communication with the first and second antennas, respectively.

[0008] The invention is based on the understanding that the antenna array does not need to be doubled to enable redundant hardware. Instead, according to the invention, two transceivers are used, both connected to the same antennas. Thus, two transceivers utilize the same antenna array. This allows the data acquired by the first transceiver to be compared with the data acquired by the second transceiver in order to detect malfunctions in the radar system. These malfunctions could, for example, be interference from one of the transceivers or a mechanical fault in the antenna array.

[0009] As will be explained in more detail later, when operating both transceivers simultaneously, the antenna can be divided between the transceivers, for example by time-division multiplexing or frequency-division multiplexing.

[0010] According to the invention, a duplication of almost the entire system and in particular the signal processing is thus made possible, whereby the size of the radar device remains almost unchanged.

[0011] In general, radar systems are used to detect objects. To do this, the transceivers activate the antenna array and transmit radio waves into the monitored area. If an object is present in the monitored area, some of the radio waves can be reflected back by the object and received by the antenna array. The reflected radio signal can then be detected by the transceivers, and information about the object's presence, position, and other characteristics can be deduced from the signal. Furthermore, the relative velocity of the object to the radar system can be determined by measuring the Doppler shift in the frequency of the received radio waves relative to the transmitted radio waves.

[0012] By detecting objects using radar, objects can be reliably detected even in difficult visibility conditions, such as snow, rain, fog or dust.

[0013] The radar device can then output information about the detected objects, for example to the vehicle control system of a vehicle on which the radar device is mounted. The radar device can also be used in stationary applications, such as with a welding machine, to detect the correct insertion of a workpiece and / or the absence of people near the workpiece.

[0014] The radar device can therefore be trained to detect objects at a distance of less than 100 m, in particular at a distance of less than 50 or 10 m.

[0015] Further developments of the invention can be found in the description, the drawings and the dependent claims.

[0016] According to a first embodiment, the first transceiver is configured to use the first antenna as a transmitting antenna and the second antenna as a receiving antenna. Furthermore, the second transceiver can be configured to use the second antenna as a transmitting antenna and the first antenna as a receiving antenna. Thus, the first and second antennas are each used for dual purposes: once as a transmitting antenna, i.e., for radiating radio waves, for one transceiver, and once as a receiving antenna, i.e., for receiving the reflected radio waves, for the other transceiver.

[0017] According to another embodiment, the first transceiver and the second transceiver are configured to use the first and / or the second antenna sequentially and / or in different frequency ranges. Thus, time-division multiplexing and / or frequency-division multiplexing can be performed.

[0018] In time-division multiplexing (TDM), for example, the first transceiver can use the first antenna for transmission for a predetermined period, such as 100 ms. Afterwards, the second transceiver can use the first antenna for another predetermined period, also for example, 100 ms, to receive. The same applies to the second antenna. TDM can be so fast that the first and second transceivers can detect objects in the monitored area virtually simultaneously.

[0019] Frequency division multiplexing can be used as an alternative or in addition to time division multiplexing. Frequency division multiplexing allows the first and second transceivers to use different frequencies, enabling both transceivers to simultaneously use the antenna array for transmitting and receiving radio signals.

[0020] According to a further embodiment, the first antenna comprises a first connection for the first transceiver and a second connection for the second transceiver, preferably separate from the first connection. Alternatively or additionally, the second antenna can comprise a first connection for the first transceiver and a second connection for the second transceiver, preferably separate from the first connection. The transceivers can accordingly be connected to their respective antennas via separate leads. Similarly, the transceivers can be connected to their respective sub-antennas (described below) via separate leads. For example, in patch antennas, the first and second connections can be located opposite each other, for example, with respect to a point of symmetry or an axis of symmetry of the patch antenna.

[0021] Alternatively, it is also possible that the two transceivers are connected to their respective antennas (or sub-antennas) via the same feed line, at least partially. Accordingly, there can be one feed line leading to the antenna, which then splits, with sections of the feed lines leading to the two transceivers.

[0022] According to another embodiment, the first antenna and / or the second antenna comprises several sub-antennas. As explained later, these sub-antennas can, for example, be individual patch antennas. The sub-antennas can then be controlled separately by the transceivers, for example, to achieve directional characteristics. Directional characteristics can be achieved, for example, by introducing a phase shift between the signals of the individual sub-antennas. The sub-antennas can also be read out separately by the transceivers, enabling angular resolution of the received signal. In this way, the radar can scan different parts of the area to be monitored sequentially and, if necessary, detect objects present there.

[0023] In principle, the first antenna can therefore encompass or refer to all sub-antennas used by the first transceiver for transmitting. Similarly, the second antenna can encompass or refer to all sub-antennas used by the first transceiver for receiving.

[0024] According to another embodiment, the antenna array includes a third antenna which is in signal communication with the first and second transceivers. The third antenna can be used as a receiving antenna by both the first and second transceivers. Preferably, the third antenna is not used as a transmitting antenna.

[0025] The third antenna can also have sub-antennas. The descriptions of the sub-antennas of the first and second antennas, as well as the design of the first and second antennas, apply accordingly to the third antenna.

[0026] According to another embodiment, the first antenna and the second antenna have the same number of sub-antennas. Accordingly, the first and second antennas can each have, for example, 2, 3, 4, 5, 6, 7, or 8 sub-antennas. Alternatively, it is also possible for the first and second antennas to have a different number of sub-antennas. In particular, the number of sub-antennas can differ by one. For example, the first antenna can have four sub-antennas and the second antenna can have three sub-antennas.

[0027] With a different number of antennas, the first transceiver can, for example, transmit and receive with a different number of sub-antennas compared to the second transceiver.

[0028] Furthermore, it is possible that all the sub-antennas are identical. For example, each sub-antenna can comprise several patch antennas, each of which is identical (within the sub-antenna). The sub-antennas themselves can also be identical to each other. Alternatively, it is possible that the sub-antennas are at least partially different. For example, the number of patch antennas in the respective sub-antennas can differ.

[0029] The patch antennas of a sub-antenna can be arranged in a straight line, one after the other. This straight line can, in particular, be parallel to a line passing through the first and second transceivers. The sub-antennas can be arranged parallel and / or at regular intervals next to each other. Any other arrangement is, of course, also possible.

[0030] The individual antennas allow for directional control and thus antenna gain. These antennas can also perform a technique called "beamforming," which enables the detection of an object's angular position and / or angle size. Based on the signal propagation time from transmission to reception of the reflected signal, the object's distance can also be determined.

[0031] According to a further embodiment, the first antenna and / or the second antenna comprise one or more patch antennas, which at least partially, particularly in plan view, have, for example, a symmetrical, preferably a point-symmetrical, shape. As already explained above, the partial antennas can therefore be patch antennas and / or comprise several patch antennas. Preferably, the radar device comprises exclusively patch antennas. A patch antenna can, for example, be designed as a flat metal surface on a circuit board. Below the patch antenna, on another plane (i.e., on another layer) of the circuit board, a large-area metallization can be provided, which causes the radiation of radio signals in a preferred direction.

[0032] Preferably, the shape of the antennas and the arrangement of the first and second transceivers can be axially and / or point-symmetric, with the axis of symmetry or the point of symmetry being located midway between the first and second transceivers.

[0033] According to a further embodiment, the connection between the first transceiver and the first antenna and / or the second antenna comprises a microstrip line. Similarly, the connection between the second transceiver and the first antenna and / or the second antenna can comprise a microstrip line. The microstrip line can be formed by a longitudinal metallization on a printed circuit board. The antennas, the microstrip line, and the transceivers are preferably arranged, particularly on the same side, on the same printed circuit board.

[0034] The radio waves emitted and received by the antennas can, for example, have a frequency between 20 and 100 GHz, preferably between 60 and 62 GHz.

[0035] The first and second transceivers may in particular be pre-made radar ICs, i.e. integrated circuits with a separate package, with the transceivers being soldered onto the circuit board.

[0036] Preferably, the connections between the transceivers and the antennas, i.e., for example, the microstrip lines, are designed so that there are no crossings of the connections. In this way, crosstalk and unwanted radiation can be avoided.

[0037] According to another embodiment, the first antenna and the second antenna (and optionally also the third antenna) are arranged between the first and second transceivers. Accordingly, the transceivers can be positioned above and below the antennas in a top view. This can result in a point-symmetrical configuration. Such a configuration simplifies the arrangement of the connections or microstrip lines, since the antennas or partial antennas on one side only need to be connected to one transceiver.

[0038] It is also possible that the transceivers are located on the same side of the first and / or second antenna. In this case, the aforementioned branches can be used in the connections between the antenna and the transceiver.

[0039] According to a further embodiment, the radar device comprises a control unit which is in signal communication with both the first transceiver and the second transceiver and is configured to compare data acquired by the first transceiver with data acquired by the second transceiver.

[0040] According to another embodiment, the control unit is designed to output an error signal when a difference is detected between the data acquired by the first transceiver and the data acquired by the second transceiver.

[0041] The control unit can be configured to compare one or more different parts of the transceiver data. For example, the control unit can compare the signal levels of the received radio waves, the signal travel time to and from the object, and / or the direction from which the signals are received.

[0042] It is also possible for the control unit to compare the data at a more abstract level. For example, the control unit can be configured to check whether an object has been detected by both the first and second transceivers. If a difference in the data is detected—for instance, if the difference in signal levels between the first and second transceivers exceeds a predetermined threshold, or if one transceiver fails to detect an object while the other reports one—an error signal can be issued. This error signal can then trigger a safety-related action, such as stopping or slowing down the machine or vehicle to which the radar device is attached.

[0043] According to another embodiment, the first and second transceivers are identical in construction. Accordingly, the first and second transceivers can be the same type of integrated circuit. Using identical transceivers ensures a high degree of comparability of the data acquired by the transceivers.

[0044] The radar device described herein can also be used in a radar array. The radar array can comprise several radar devices, which are arranged, in particular, side by side and / or adjacent to each other. The individual radar devices in the array can then be used for smaller angular ranges in order to increase the overall angular resolution of the array.

[0045] A further subject of the disclosure is a method for operating a radar device in which at least a first transceiver and a second transceiver are connected to a first and a second antenna, and both the first transceiver and the second transceiver transmit and / or receive radio signals via the first and the second antenna.

[0046] The descriptions of the radar device apply accordingly to the procedure. This applies in particular to advantages and embodiments. Furthermore, it is understood that all features mentioned herein can be combined unless explicitly stated otherwise.

[0047] The invention is described below purely by way of example with reference to the drawings. They show: Fig. 1 schematically a radar device and an object detected by the radar device; Fig. 2 a radar device with a first embodiment of an antenna array; Fig. 3 a radar device with a second embodiment of an antenna array; Fig. 4 a radar device with a third embodiment of an antenna array; Fig. 5 a radar device with a fourth embodiment of an antenna array; Fig. 6 a radar device with a fifth embodiment of an antenna array, wherein the transceivers are arranged on the same side of the antenna array.

[0048] Fig. Figure 1 shows a radar device 10 with an antenna array 12, which has a first antenna 14 and a second antenna 16.

[0049] The radar device 10 comprises a first transceiver 18 and a second transceiver 20, which are each connected to the first and second antennas 14, 16 in terms of signal technology.

[0050] An example is Fig. Figure 1 shows a transmitted signal 22, which is emitted into a room to be monitored and there encounters an object 24. A portion of the transmitted signal 22 is reflected back by the object 24 as a received signal 26 to the radar device 10 and received there by the antenna array 12. The received signal 26 at a given time can, for example, be detected by the first transceiver 18, whereupon the first transceiver 18 detects the object 24.

[0051] The first transceiver 18 and the second transceiver 20 are connected to a control unit 30 via data lines 28. The control unit 30 receives data acquired by the transceivers 18 and 20 and compares it. For example, if the first transceiver 18 indicates that an object has been detected, but the second transceiver 20 does not, an error occurs, in which case the control unit 30 outputs an error signal via an interface 32.

[0052] Fig. Figure 2 shows a top view of a radar device with a first embodiment (shown specifically here) of the antenna array 12 with patch antennas 36. The antenna array 12 comprises seven sub-antennas 34, each of which includes six patch antennas 36. The patch antennas 36 are each square in shape and all have the same shape and size.

[0053] Six patch antennas 36 connected in series form a sub-antenna 34. A microstrip line 40 can also be provided between the individual patch antennas 36 as a connection between them. The patch antennas 36 of a sub-antenna 34 are arranged in a straight line one behind the other. The sub-antennas 34 are arranged parallel to each other at regular intervals. Other arrangements are of course also possible.

[0054] It can be seen that the first transceiver 18 uses three of the sub-antennas 34 as transmitting antennas (the three in Fig. 2 sub-antennas 34 shown on the right). These three sub-antennas 34 together form the first antenna 14. Three further sub-antennas 34 (in Fig. The sub-antennas 34 of the first antenna 14 are used by the first transceiver 18 as receiving antennas and accordingly form the second antenna 16. The sub-antennas 34 of the first antenna 14 are used by the second transceiver 20 as receiving antennas, whereas the sub-antennas 34 of the second antenna 16 are used by the second transceiver 20 as transmitting antennas.

[0055] The middle partial antenna 34 is used by both transceivers 18, 20 as a receiving antenna and thus forms a third antenna 38. Both transceivers 18, 20 therefore transmit with three partial antennas 34 each and receive with four partial antennas 34.

[0056] Each sub-antenna 34 is connected to one of the transceivers 18, 20 via a microstrip line 40. The microstrip lines 40 and the patch antennas 36 are arranged on a single circuit board 42. The transceivers 18, 20 are implemented as chips or radar ICs and are soldered onto the circuit board 42.

[0057] In the area below the patch antennas 36 a backplane 44 (i.e. a metallization on another layer of the circuit board 42) is attached to enable directional radiation of the transmit signal 22.

[0058] Fig. Figure 3 shows a second embodiment of the antenna array 12. In the embodiment of Fig. 3 was compared to Fig. 2. One partial antenna 34 is removed on the left side. Accordingly, the first transceiver 18 uses only three partial antennas 34 for receiving instead of four. The second transceiver 20 uses only two partial antennas 34 for transmitting.

[0059] Fig. Figure 4 shows a third embodiment of the antenna array 12. In comparison to the embodiment of Fig. Each sub-antenna 34 comprises only 4 patch antennas 36. By using fewer patch antennas 36 arranged in a straight line, the transmitted signal 22 is less strongly focused in the direction of the straight line. This can result in a different scanning range or a different area to be monitored.

[0060] Fig. Figure 5 shows a fourth embodiment of the antenna array 12. This embodiment differs from the embodiment of Fig. 4 in that two sub-antennas 34 of the first antenna 14 have only two patch antennas 36 connected in series. This can result in a different radiation characteristic for the transmit signal 22 and also a different reception characteristic for the receive signal 26.

[0061] In the embodiments of the Fig. In embodiments 2 to 5, the antenna array 12 is located between the first transceiver 18 and the second transceiver 20. At least in the embodiments according to Fig. Furthermore, parts 2-4 are symmetrically formed.

[0062] Fig. Figure 6 now shows a fifth embodiment in which both transceivers 18, 20 are arranged on the same side of the antenna array (for example, on the circuit board 42). In the embodiment of Fig. In 6, only a first antenna 14 and a second antenna 16 are present, each comprising only one sub-antenna 34 with three patch antennas 36 connected in series. The microstrip lines 40, which connect the sub-antennas 34, include a branch 46 such that each of the sub-antennas 34 is connected, at least partially, to the first transceiver 18 and also to the second transceiver 20 via the same microstrip line 40.

[0063] By using two transceivers 18, 20, which use the same antenna array 12, redundancy can be created without significantly increasing the size of the radar 10. The radar 10 can therefore be used in safety-related applications, since in particular the control unit 30 can detect faults in the radar 10 and output a corresponding fault signal. List of reference symbols 10 radar unit 12 antenna array 14 first antenna 16 second antenna 18 first transceiver 20 second transceiver 22 Transmission signal 24 objects 26 Received signal 28 data lines 30 control unit 32 interface 34 partial antenna 36 Patch antenna 38 third antenna 40 microstrip lines 42 ladder map 44 Backplane 46 Junction

Claims

[1] Radar device (10) with - an antenna array (12) having at least a first antenna (14) and a second antenna (16), - at least a first transceiver (18) and a second transceiver (20) where both the first transceiver (18) and the second transceiver (20) are in signal connection with the first antenna (14) and the second antenna (16), respectively. [2] Radar device (10) according to claim 1, wherein the first transceiver (18) is designed to use the first antenna (14) as a transmitting antenna and the second antenna (16) as a receiving antenna and the second transceiver (20) is designed to use the second antenna (16) as a transmitting antenna and the first antenna (14) as a receiving antenna. [3] Radar device (10) according to claim 1 or 2, wherein the first transceiver (18) and the second transceiver (20) are designed to use the first and / or second antenna (16) sequentially and / or in different frequency ranges. [4] Radar device (10) according to one of the preceding claims, wherein the first antenna (14) comprises a first connection for the first transceiver (18) and a second connection, separate from the first connection, for the second transceiver (20), and / or wherein the second antenna (16) comprises a first connection for the first transceiver (18) and a second connection, separate from the first connection, for the second transceiver (20). [5] Radar device (10) according to one of the preceding claims, wherein the first antenna (14) and / or the second antenna (16) comprises a plurality of sub-antennas (34). [6] Radar device (10) according to one of the preceding claims, wherein the antenna array (12) comprises a third antenna (38) which is in signal connection with the first and the second transceiver (20), wherein the first and / or the second transceiver (20) are preferably designed to use the third antenna as a receiving antenna. [7] Radar device (10) according to claim 5 or 6, wherein the first antenna (14) and the second antenna (16), and preferably the third antenna (38), have the same or different numbers of sub-antennas (34), wherein the partial antennas (34) are preferably each identical or at least partially different. [8] Radar device (10) according to one of the preceding claims, wherein the first antenna (14) and / or the second antenna (16) comprise one or more patch antennas (36) which at least partially have a symmetrical, preferably a point-symmetrical shape. [9] Radar device (10) according to one of the preceding claims, wherein the connection between the first transceiver (18) and the first antenna (14) and / or the second antenna (16) and / or the connection between the second transceiver (20) and the first antenna (14) and / or the second antenna (16) a microstrip line (40). [10] Radar device (10) according to one of the preceding claims, wherein the first antenna (14) and / or the second antenna (16) is arranged between the first transceiver (18) and the second transceiver (20). [11] Radar device (10) according to one of the preceding claims, comprising a control unit (30) which is in signal connection with both the first transceiver (18) and the second transceiver (20) and is designed to compare data acquired by the first transceiver (18) with data acquired by the second transceiver (20). [12] Radar device (10) according to claim 11, wherein the control unit (30) is designed to output an error signal upon detection of a difference between the data acquired by the first transceiver (18) and the data acquired by the second transceiver (20). [13] Radar device (10) according to one of the preceding claims, wherein the first transceiver (18) and the second transceiver (20) are identical in construction.

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