Radar sensor assembly and motor vehicle

Abstract

The invention relates to a radar sensor arrangement (1) for detecting an object. The invention relates to a radar sensor assembly (1) comprising:-an antenna assembly (2) having a receiving circuit (5) with a plurality of receiving antennas (6A, 6B, 6C, 6D) and a transmitting circuit (3) with a plurality of transmitting antennas (4A, 4B, 4C),-a central control circuit (7) with a microcontroller (8). The microcontroller (8) is configured for operating the antenna assembly (2) in one of predetermined, at least two different operating modes. The invention also relates to a motor vehicle.

Description

Technical Field

[0001] This invention relates to a radar sensor assembly for identifying objects. The invention also relates to a motor vehicle that includes the radar sensor assembly. Background Technology

[0002] Radar technology has been well-known since the early 20th century. Radar technology is based on the principle of emitting electromagnetic waves, receiving the echoes of the emitted electromagnetic waves, and analyzing the received signals according to various standards as needed. Depending on the specific implementation, various information about the object causing the echo reflection can be obtained. For example, radar technology can be used for localization. Furthermore, information about the relative motion between the transmitter and the object, information about the absolute velocity of either, or information about the object's outline can be obtained (depending on the implementation).

[0003] The application of radar in automotive technology is becoming increasingly important. One reason for this is the desire to improve vehicle autonomy, which has driven the further development of automotive sensors.

[0004] Currently, radar sensor assemblies for equipment such as vehicles are offered as out-of-the-box systems that provide a high level of detection range and lateral resolution for object recognition.

[0005] For various reasons (not just regulatory ones), these radar sensor components can operate, for example, in a frequency range between 24 GHz and 81 GHz, with radar sensors operating in the range between 77 GHz and 81 GHz being a common variant. The frequency range mentioned is sometimes referred to as mmWave (millimeter wave) in English due to the wavelength of the emitted electromagnetic waves.

[0006] The advantages of using radar sensors are: since the basic working principle is to obtain information by using the echo of electromagnetic waves, the information that can be obtained exceeds the results that can be obtained by using ultrasonic sensors; and compared with using lidar systems, radar sensors have the advantage of lower procurement costs.

[0007] As more and more sensors are deployed (for example, on motor vehicles), the fundamental requirement to ensure that sensors operate for as long as possible becomes more important. Summary of the Invention

[0008] Therefore, the object of the present invention is to make the practicality of radar wave-based sensors more flexible and improved.

[0009] This objective is achieved by a radar sensor assembly having the features of claim 1 and a motor vehicle having the features of claim 20.

[0010] The radar sensor assembly according to the present invention is used to identify objects.

[0011] A radar sensor assembly includes an antenna assembly with receiving and transmitting circuitry. The receiving circuitry has multiple receiving antennas, and the transmitting circuitry has multiple transmitting antennas. For example, the antenna assembly may be specified to have three transmitting antennas and four receiving antennas; this configuration is found in some commercially available radar sensors.

[0012] The radar sensor assembly also features a central control circuit with a microcontroller. This microcontroller-equipped control circuitry controls the receiving and transmitting circuits, and, when necessary, analyzes and / or selects received signals and forwards them to other computing units for analysis, such as a central controller connected to the microcontroller in the vehicle.

[0013] According to the present invention, the microcontroller is configured to operate the antenna assembly in one of at least two preset different operating modes. The first operating mode is an energy-saving mode, and the second operating mode is a detection mode.

[0014] According to the present invention, by programming the microcontroller accordingly, an energy-saving mode is set in addition to the detection mode (which may also be called the normal mode), which is accompanied by a lower power consumption.

[0015] Therefore, according to the present invention, the radar sensor assembly can be switched from an energy-saving mode to a conventional detection mode by driving the antenna assembly with a microcontroller; and / or the radar sensor assembly can be switched from a conventional detection mode to an energy-saving mode by driving it with a microcontroller.

[0016] For example, it can be specified that in energy-saving mode, the transmitting circuit operates according to the first transmitting control sequence of the transmitting antenna, while in detection mode, the transmitting circuit operates according to the second transmitting control sequence of the transmitting antenna. Here, the driving and control process triggered by the first transmitting control sequence is less than that of the second transmitting control sequence.

[0017] For example, it can be specified that the first and second transmit control sequences cover a time period of equal duration. However, within this same time period, the first transmit control sequence specifies that one or more transmit antennas are not controlled more frequently than in the second transmit control sequence. Alternatively, it can be expressed as follows: within the same time period, the number of times the transmit antennas are controlled in the first transmit control sequence is generally less than the number of times controlled in the second transmit control sequence. In the transmission operation of radar sensor components, it can be specified that the transmit control sequence predefines the order in which the transmit antennas are controlled, and this sequence is repeated.

[0018] Therefore, for example, it can be specified that in the second transmit control sequence, N control time points are set within a one-second time period, where n control processes are triggered at each control time point when there are n transmit antennas. In this specific example, n control processes are executed at N Hz. Alternatively, it can be specified that in the first control sequence, N control time points are set within a one-second time period, where only one control process is triggered at each control time point when there are n transmit antennas; that is, only one transmit antenna is controlled at a single control time point, where "N" and "n" represent positive integers greater than 0. Therefore, in the first transmit control sequence, one or more transmit antennas are not controlled more frequently than in the second transmit control sequence.

[0019] Specifically, it can be specified that the first launch control sequence and the second launch control sequence have the same number of control processes per unit time. Furthermore, it can be preferably specified that the first launch control sequence and the second launch control sequence have the same length.

[0020] For example, it can be specified that the microcontroller is configured to sequentially (meaning at least at one control time point, preferably at more than one control time point, particularly preferably at each control time point) not control at least one of the plurality of transmit antennas during the first transmit control sequence. In other words, this means that the first transmit control sequence specifies that the transmit antennas are controlled according to time, such that there is at least one control time point where at least one of the transmit antennas of the plurality of transmit antennas is not controlled. Preferably, the microcontroller is configured such that during the first transmit control sequence, and in each control process of the transmit control sequence, at least one of the transmit antennas of the plurality of transmit antennas is not controlled.

[0021] Because the transmission control sequence is configured such that at least one transmission antenna is not controlled at each control time point, and if necessary, at multiple control time points, and preferably at each control time point, the energy requirement for transmitting signals in energy-saving mode is lower compared to the case where each antenna is controlled at each control time point. Another advantage of the method according to the invention is that development can be achieved in many places by configuring the control, and theoretically, existing radar sensors can be given the described advantages through targeted configuration.

[0022] Preferably, at least one antenna is driven at each driving control time point. This achieves a reduction in energy demand compared to normal operation without incurring excessive delays when analyzing moving objects. In other words, the impact on temporal resolution is minimal during radar sensor operation.

[0023] Particularly preferably, during the first transmit control sequence, exactly one of the transmit antennas is controlled sequentially (meaning at least at one control time point, preferably at more than one control time point, and particularly preferably at each control time point). This means that exactly one transmit antenna is controlled at each control time point in the first transmit control sequence; using this approach, the energy consumption for transmitting signals is minimized to a large extent. Specifically, a set of control processes is preferably implemented in the first transmit control sequence, in which the transmit antennas of the transmit circuit are controlled sequentially for transmission. Thus, in the transmit control sequence, each transmit antenna is controlled exactly once, and then, if necessary, one of the transmit antennas is controlled a second time.

[0024] In the first transmit control sequence, each transmit antenna is controlled exactly once, and then the first transmit control sequence is repeated. This improved scheme is particularly preferred. Therefore, this embodiment specifies that the number of preset control time points and control processes in the first transmit control sequence is exactly the same as the number of transmit antennas in the antenna assembly. Thus, if the antenna assembly has, for example, three transmit antennas, according to this embodiment, in the transmit control sequence, each of the three transmit antennas is controlled exactly once, and then the first transmit control sequence is repeated, that is, the duration and frequency are the same as in the case of the antenna assembly in power-saving mode. When the antenna assembly switches to detection mode, the second transmit control sequence is preferably of the same length, so the number of set control time points is the same as the number of transmit antennas, where, for example, each transmit antenna is controlled at each control time point. That is, for example, in the case of three transmit antennas and three control time points, three transmit antennas are controlled, and then the second transmit control sequence is repeated. This is the same consideration that, according to this consideration, as long as the antenna assembly is operating in detection mode, all antennas will be controlled at a predetermined control frequency.

[0025] Unlike the first transmit control sequence, in the simplest case, a second transmit control sequence can be predefined (based on the second transmit control sequence, the transmit antenna control in the detection mode is predefined), such that each transmit antenna in the existing transmit antennas is continuously controlled according to the transmit frequency, that is, controlled without interrupting the control time points. In contrast, in the energy-saving mode, a defined sequence is set for each transmit antenna in the existing transmit antennas, these sequences being referred to above as the first transmit control sequence, and these sequences specify, for example, that at least one transmit antenna in the transmit antennas is not controlled during at least one step of a sequence, and preferably, at least one transmit antenna in the plurality of transmit antennas is not controlled during each control process of the sequence. The length of the sequence is determined by design and can be freely chosen by those skilled in the art. For example, it can be specified that the transmit control sequence has N control time points, and the transmit control sequence is repeated after completing N control processes, thereby executing the same transmit control process again.

[0026] The above description of the operation of a transmitting circuit with a transmitting antenna under the first and second transmitting control sequences can be applied in a completely similar way to the operation of a receiving circuit with a receiving antenna under the first and second receiving control sequences.

[0027] For example, it can be specified that in energy-saving mode, the receiving circuit operates with the first receiving control sequence of the receiving antenna, while in detection mode, the receiving circuit operates with the second receiving control sequence of the receiving antenna. Here, the first receiving control sequence triggers fewer control processes than the second receiving control sequence.

[0028] For example, it can be specified that the first and second receive control sequences cover the same time period, but within the same time period, the first receive control sequence specifies that one or more receiving antennas are not controlled more frequently than in the second receive control sequence. In the receiving operation of the radar sensor assembly, it can be specified that the receive control sequence pre-sets the control order of the receiving antennas and repeatedly executes this sequence.

[0029] Therefore, for example, it can be specified that in the second receive control sequence, N control time points are set within a one-second time period, where n control processes are triggered at each control time point when there are n receive antennas. In this specific example, n control processes are executed at N Hz. Furthermore, it can be specified that in the first control sequence, N control time points are set within a one-second time period, where only one control process is triggered at each control time point when there are n receive antennas, i.e., only one receive antenna is controlled at each control time point, where "N" and "n" represent positive integers > 0. Therefore, in this receive control sequence, the situation where one or more receive antennas are not controlled is more frequent than in the second receive control sequence.

[0030] Specifically, it can be specified that the first receiving drive sequence and the second receiving drive sequence have the same number of drive processes per unit time. Preferably, it can also be specified that the first receiving drive sequence and the second receiving drive sequence have the same length.

[0031] For example, it can be specified that the microcontroller is configured to sequentially (meaning at least at one control time point, preferably at more than one control time point, particularly preferably at each control time point) not control at least one of the plurality of receiving antennas during the first receive control sequence. In other words, this means that the first receive control sequence specifies that the receiving antennas are controlled according to time, such that there is at least one control time point at which at least one of the plurality of receiving antennas is not controlled. Preferably, the microcontroller is configured such that during the first receive control sequence, at least one of the plurality of receiving antennas is not controlled in each control process of the receive control sequence.

[0032] Since the set receive control sequence specifies that at least one receive antenna is not controlled at each control time point in the receive control sequence, and if necessary, even at multiple control time points, and preferably at each control time point in the receive control sequence, the energy requirement for transmitting signals in the energy-saving mode is lower compared to the case where each antenna is controlled at each control time point.

[0033] Preferably, at least one antenna is driven at each driving control time point. This achieves a reduction in energy demand compared to normal operation without incurring excessive delays when analyzing moving objects. In other words, the impact on temporal resolution is minimal during radar sensor operation.

[0034] It is particularly preferred that during the first receive drive sequence, exactly one of the receiving antennas is driven sequentially (meaning at least at one drive time point, preferably at more than one drive time point, particularly preferably at each drive time point), which means that exactly one receiving antenna is driven at each drive time point of the first receive drive sequence; this approach greatly reduces the energy consumption used to receive signals.

[0035] Specifically, in the first receive drive sequence, a set of drive processes is preferably executed, in which the receiving antennas of the receiving circuit are driven sequentially to perform reception. Therefore, in the receive drive sequence, each receiving antenna is driven exactly once, and then, if necessary, one of the receiving antennas is driven a second time.

[0036] In the first receive control sequence, each receiving antenna is controlled exactly once, and then the first receive control sequence is repeated. Therefore, this embodiment specifies that the number of control time points and control processes in the first receive control sequence is exactly the same as the number of receiving antennas in the antenna assembly. Thus, if the antenna assembly has, for example, three receiving antennas, according to this embodiment, each of the three receiving antennas is controlled exactly once in the receive control sequence, and then the first receive control sequence is repeated. That is, the duration and frequency are the same as when the antenna assembly operates in power-saving mode. When the antenna assembly switches to detection mode, the second receive control sequence is preferably of the same length, so the number of control time points is exactly the same as the number of receiving antennas. For example, each receiving antenna is controlled at each control time point; that is, for example, three receiving antennas are controlled when there are three receiving antennas and the duration is three control time points. The second receive control sequence is then repeated. This is consistent with the consideration that, according to this consideration, as long as the antenna assembly operates in detection mode, all antennas will be controlled at a predetermined control frequency.

[0037] Unlike the first receive control sequence, in the simplest case, a second receive control sequence (based on the second receive control sequence, pre-defined in the detection mode) can be defined so that each of the existing receive antennas is continuously controlled according to the receiving frequency, that is, controlled without interrupting the control time points. In contrast, in the energy-saving mode, a defined sequence is set for each of the existing receive antennas, these sequences being referred to above as the first receive control sequence, and these sequences specify, for example, that at least one receive antenna is not controlled during at least one step of a sequence, and preferably, at least one of the plurality of receive antennas is not controlled during each control process of the sequence. The length of the sequence is determined by design and can be freely chosen by those skilled in the art. For example, it can be specified that the receive control sequence has N control time points, and the receive control sequence is repeated after completing N control processes, thereby executing the same receive control process again.

[0038] In principle, the operation of the transmitting circuit and the receiving circuit can be parallel. Specifically, it can be specified that the first transmitting control sequence and the first receiving control sequence have the same number of control processes; and / or the second transmitting control sequence and the second receiving control sequence have the same number of control processes. In particular, the first transmitting control sequence and the second transmitting control sequence, as well as the first receiving control sequence and the second receiving control sequence, all have the same number of control time points.

[0039] According to a preferred improvement, the transmit power for a single driven antenna is set higher during the drive control process in the first operating mode than during the drive control process in the second operating mode. Preferably, the transmit power for a single driven antenna in the drive control process in the first operating mode is higher than in each drive control process in the second operating mode. Particularly preferably, the transmit power for a single driven antenna in each drive control process performed in the first operating mode is higher than in the case of the second operating mode.

[0040] This specifically means that, for one or more (preferably all) transmit drive processes in the first operating mode, the one or more transmit antennas driven to transmit signals are driven at a higher transmit power for a single driven antenna than in the second operating mode. This means that, at a given drive time point in the first operating mode, the drive of the transmit antenna according to the above description (if such drive is indeed performed) is at a higher transmit power relative to the second operating mode. This may apply to at least one drive time point, but may also apply to multiple or all drive time points.

[0041] For example, it can be specified that in the first operating mode, the transmit drive sequence has at least one high-power drive, preferably exactly one high-power drive, in which the transmit antenna, preferably exactly one transmit antenna, operates at a higher transmit power for a single driven antenna than is specified for each drive process in the second operating mode.

[0042] This, for example, in one implementation means that: in a first operating mode, in the transmit drive sequence, one or exactly one drive process of a single transmit antenna (preferably exactly one transmit antenna) is performed with an enhanced transmit power for a single driven antenna, while other drive processes in the transmit drive sequence in the first operating mode are performed with a predetermined first transmit power for a single driven antenna. In a second operating mode, the drive processes of the transmit drive sequence are performed with a predetermined second transmit power for a single driven antenna. It is conceivable that the predetermined first transmit power and the predetermined second transmit power for a single driven antenna are the same or only slightly different, for example, differing from each other by + / - 10% of the higher of the two values. The decisive factor here is that one or more of the aforementioned drive processes of the transmit antenna are performed with an enhanced transmit power that is enhanced compared to the first and second transmit power for a single driven antenna, for example, at least twice as high. For example, it can be specified that exactly one drive control process in exactly one drive control process of exactly one transmit antenna is executed with an enhanced transmit power, wherein the enhanced transmit power is the maximum transmit power of the radar sensor assembly or at least 80% of the maximum transmit power. The first total transmit power (i.e., the total transmit power of the sum of the first transmit powers predetermined for a single driven antenna in one drive control process) and the second total transmit power (i.e., the total transmit power of the sum of the second transmit powers predetermined for a single driven antenna in one drive control process) are small for each drive control process, for example, between 10% and 75% of the maximum transmit power of the radar sensor assembly. If, as preferred, the predetermined first transmit power and the predetermined second transmit power for a single driven antenna are the same or only slightly different (e.g., differing from each other by + / - 10% of the higher of the two values), then since the first drive control sequence triggers fewer drive control processes than the second drive control sequence, less energy conversion is required in the first drive control sequence compared to the second drive control sequence, i.e., lower energy demand.

[0043] In the first operating mode, which is an energy-saving mode, transmitting a signal at a higher transmission power compared to the transmission power in the second operating mode seems to contradict the implementation of the first operating mode as an energy-saving mode, and is therefore counterintuitive. The transmission signal in the first operating mode and the transmission power in the second operating mode are determined as follows: since the number of drive control processes in the first operating mode is less than the number of drive control processes in the second operating mode, although high-power drive control is performed in the first operating mode, energy-saving characteristics are still achieved overall in the first operating mode compared to the second operating mode.

[0044] The advantage of performing high-power drive control in the first operating mode is that it allows for the acquisition of radar information at a greater distance. This information can then be used, for example, to analyze whether to switch from energy-saving mode to detection mode.

[0045] Preferably, the transmission frequency bandwidth used in the drive control process of the first operating mode is smaller than that in the second operating mode. This can be achieved, for example, by having each drive control process in the first operating mode have a smaller transmission frequency bandwidth than each drive control process in the second operating mode; that is, any bandwidth of the drive control process in the first operating mode is smaller than any bandwidth of the drive control process in the second operating mode. While a smaller bandwidth results in lower range resolution, on the other hand, if information is needed for analysis to identify approaching signals at relatively long distances and to switch to detection mode upon detection, high range resolution is not particularly meaningful. Setting a small bandwidth gives the detected signal advantageous characteristics, especially reducing the analysis burden on the microcontroller of the radar sensor assembly, thus contributing to the desired energy-saving effect. Therefore, combining relatively high transmission power with relatively low frequency bandwidth presents advantages.

[0046] Particularly preferably, the sampling rate for sampling the received signal is lower in the first operating mode compared to the second operating mode. This results in a lower analytical burden at the microcontroller level, which in turn contributes to lower power consumption.

[0047] In a preferred improvement of the radar sensor assembly, for example, it can be specified that multiple sampling rate schemes are stored in the storage device of the central control circuit. The sampling rate depends on a parameter of the radar response; more precisely, the sampling rate depends on one parameter of the radar response or multiple parameters of the radar response. Therefore, the sampling rate is selected based on the analysis of the radar response. This approach allows the sampling rate to be adjusted according to predefined parameters. These predefined parameters can be derived empirically and stored in the storage device, for example, through a reference scenario that simulates the expected application scenario through empirical exercises.

[0048] In another embodiment, it can be specified that in a first operating mode, each of the plurality of transmit antennas is configured with a different chirp to drive the transmit antenna; and / or in a second operating mode, each of the plurality of transmit antennas is configured with a different chirp to drive the transmit antenna. By setting different chirs for each antenna, the analysis of the received signal can be improved.

[0049] Alternatively or additionally, it may be specified that a first chirp configuration is configured in a first operating mode to drive the transmitting antenna, and a second chirp configuration is configured in a second operating mode to drive the transmitting antenna. Preferably, all receiving antennas are driven in the same manner in the first operating mode, the second operating mode, or both operating modes.

[0050] It is particularly preferred that the first chirp configuration is established such that, for one transmitting antenna, for multiple transmitting antennas, or for all transmitting antennas, a driving process with higher transmitting power and narrower transmitting frequency bandwidth for a single driven antenna and a driving process with lower transmitting power and wider transmitting frequency bandwidth for a single driven antenna are alternately performed.

[0051] Alternatively, it can be specified that a first chirp configuration is established, for one transmit antenna, for multiple transmit antennas, or for all transmit antennas, alternating between a first drive process with a first transmit power and a first transmit frequency bandwidth for a single driven antenna and a second drive process with a second transmit power and a second transmit frequency bandwidth for a single driven antenna, wherein the second transmit power is zero watts or close to zero watts, for example, the transmit power for a single driven antenna is no more than 5% of the maximum transmit power of the radar sensor assembly, and the second bandwidth is zero Hz or close to zero Hz, for example, no more than 5% of the maximum bandwidth; alternatively or additionally, the second bandwidth is preferably less than 100 Hz. This practice is referred to below as "ghost chirps". In particular, it can be specified that the term "alternating" includes: only every nth drive process is a first drive process, and between two such drive processes, a number of n-1 second drive processes are performed, where n represents a positive integer greater than or equal to 2, and n is preferably a number from 3 to 10, for example, 5. This approach achieves significant energy demand for transmitting radar signals only in relatively rare cases (i.e., every nth transmission) through low-consumption methods. This method is based on the assumption that, unlike detection mode, there is no need for data with higher temporal resolution in energy-saving mode. Preferably, the same analysis procedure, especially the same mathematical filtering, is used in both the first and second operating modes. Although the minimum bandwidth and transmit power are zero or near zero Hz and zero watts, the second drive process is also actually performed, thus allowing analysis to be performed in the same manner in both modes, especially using the same filter chain. To avoid errors in analysis performed via radar reception after the transmission of the phantom chirp, it is preferable that the radar sensor assembly is designed to artificially enrich the received signal chain with data (preferably using Reed-Solomon codes) for a specific (e.g., empirically determined) time period after the transmission of the phantom chirp. This makes the analysis less prone to error and more accurate overall.

[0052] To switch to detection mode at an appropriate time, the microcontroller is configured to: retrieve signals detected as radar responses by the receiving circuitry while the antenna assembly is operating in power-saving mode and perform analysis, wherein the microcontroller switches from power-saving mode to detection mode when the analysis indicates that predetermined criteria are met. Predetermined criteria may include, for example, inferring from the analysis, an obstacle, the approach of a user, or the user's intention to open the door. This can be determined, for example, by matching the detected radar response with empirically determined characteristic radar responses stored on or in memory connected to the microcontroller. The door lock can be actuated based on alternative or additional criteria.

[0053] For example, if, within a predetermined time period (e.g., one second, five seconds, ten seconds, or one minute), the radar response (i.e., the signal detected by the receiving circuitry) infers that there are no objects nearby (e.g., by means that a lower threshold for the received signal is not exceeded within a certain time period), it can, for example, switch back from detection mode to energy-saving mode. For instance, as an alternative or additional criterion for switching from detection mode to energy-saving mode, the recognition of door locking could be used, whereby the vehicle's corresponding control unit notifies the microcontroller of the radar sensor assembly of this situation with a corresponding output signal.

[0054] Preferably, the antenna assembly and the control circuitry with the microcontroller are arranged on the same printed circuit board, as this allows the radar assembly to be delivered as a compact mount, for example, to a motor vehicle manufacturer.

[0055] A particularly preferred approach is to arrange the antenna assembly and the control circuitry with a microcontroller on the same chip, forming a so-called system-on-a-chip (SoC). In such a design, the aforementioned advantages of being available as a mounting component are combined with the advantages of miniaturization, thereby increasing flexibility in terms of mounting options.

[0056] Preferably, the radar sensor assembly is designed for radar operation with radar waves in the millimeter range, and particularly preferably, the wavelength of the emitted radar waves is between 1 mm and 20 mm.

[0057] Preferably, the radar sensor assembly is designed for radar operation using radar waves with frequencies between 20 GHz and 100 GHz, particularly preferably between 77 GHz and 81 GHz. One concept of the invention is to provide a motor vehicle in which a radar sensor assembly of the above design is arranged to identify objects. The radar sensor assembly may be specifically arranged in a door handle or pillar (e.g., B-pillar), or in a design element.

[0058] Particularly preferred is that the radar sensor assembly is coupled to the vehicle's controller, and the vehicle has a keyless-entry vehicle access system coupled to the controller for authenticating the operator carrying a wireless ID transmitter. The microcontroller of the radar sensor assembly is preferably configured to switch from power-saving mode to detection mode only under the additional condition that the microcontroller receives an acknowledgment signal from the controller confirming successful authentication of the ID transmitter within radio range. For example, the keyless-entry vehicle access system can be designed as a system that transmits a polling wake-up signal, wherein the ID transmitter is configured to initiate an authentication session upon receiving the wake-up signal. For example, at the point of successful authentication, or immediately after, or within a predetermined time interval after, the controller can output an acknowledgment signal to the microcontroller of the radar sensor assembly, for example, stored as a flag within the microcontroller, and the presence of this flag is only checked if a predetermined criterion for the antenna assembly's operation to switch from power-saving mode to detection mode is met; if present, the operation of the antenna assembly is switched to detection mode. Attached Figure Description

[0059] Further details, features, and advantages of the radar sensor assembly of the present invention for a motor vehicle according to the present invention can be derived from the following description taken in conjunction with the accompanying drawings, in which exemplary embodiments of the invention are shown.

[0060] It should be understood that the features described above and those further elaborated below can be used not only in the given combinations, but also in other combinations or individually. In the accompanying drawings:

[0061] Figure 1 : A schematic diagram illustrating one embodiment of a radar sensor assembly according to the present invention;

[0062] Figure 2 : Show Figure 1 A schematic diagram of the drive and control operation of the transmitting circuit of the radar sensor assembly in power-saving mode;

[0063] Figure 3 : Show Figure 1 A schematic diagram of the drive and control operation of the transmitting circuit of the radar sensor assembly when it is in detection mode;

[0064] Figure 4 : Shows the contents Figure 1 A schematic diagram of a motor vehicle with a radar sensor assembly of the type shown. Detailed Implementation

[0065] Figure 1A schematic diagram of radar sensor assembly 1 is shown. The radar sensor assembly includes antenna assembly 2. The antenna assembly includes transmitting circuit 3 with three transmitting antennas 4A, 4B, and 4C. Additionally, the antenna assembly includes receiving circuit 5 with four receiving antennas 6A, 6B, 6C, and 6D. A central control circuit 7 with microcontroller 8 is connected to the antenna assembly.

[0066] The microcontroller 8 is used to control the antenna circuit and is configured to operate the antenna assembly in one of two different predetermined operating modes, wherein the first operating mode is an energy-saving mode and the second operating mode is a detection mode.

[0067] Energy-saving mode in Figure 2 The diagram illustrates the control of the transmit antennas in power-saving mode through a transmit control sequence. The transmit control sequence has six time points 1 to 6, displayed on the t-axis. For each control time point, the currently controlled transmit antenna is indicated by a marker in the graph (row A, row B, or row C, depending on the antenna). At each control time point, exactly one transmit antenna is controlled sequentially; more precisely, each transmit antenna undergoes the same number of control processes (two in the illustrated case).

[0068] exist Figure 3 In the detection mode shown, the transmitting circuit operates with a second transmit drive sequence for the transmitting antennas, wherein this transmit drive sequence is defined in six drive processes, and all three antennas are driven in each of these drive processes. This means the following result: In Figure 2 The first launch control sequence shown triggers six control processes, while... Figure 3 The second transmit drive sequence shown triggers eighteen drive processes. This means that fewer drive processes are triggered in the first transmit drive sequence than in the second, thus achieving the desired energy-saving effect. The illustrations of the receive drive sequence in energy-saving mode and detection mode should be understood as being the same as in... Figure 2 and Figure 3 The illustrations seen are similar, of course, when using according to Figure 1 When designing radar sensor components, four receiving antennas should be taken into account.

[0069] from Figure 4 The image shows a motor vehicle 9, which includes a radar sensor assembly 1, used to identify objects. The radar sensor assembly 1 is, for example, located in a B-pillar 10.

[0070] The radar sensor assembly 1 is connected to the vehicle's controller 11. The operator carrying the wireless ID transmitter 12 is authenticated by the vehicle's keyless entry system, and the controller notifies the microcontroller of the radar sensor assembly 1 of this. The microcontroller is configured to enter detection mode only if it has received an acknowledgment signal from the controller 11 within a predetermined time period confirming successful authentication of the ID transmitter 12 within its radio range.

Claims

1. A radar sensor assembly (1) for identifying objects, wherein, The radar sensor assembly (1) has at least the following features: - Antenna assembly (2), the antenna assembly having: A receiving circuit (5) with multiple receiving antennas (6A, 6B, 6C, 6D) and a transmitting circuit (3) with multiple transmitting antennas (4A, 4B, 4C). - A central control circuit (7) with a microcontroller (8), the central control circuit being connected to the receiving circuit (5) and the transmitting circuit (3), The microcontroller (8) is configured to operate the antenna assembly in one of at least two predetermined operating modes. The first operating mode is the energy-saving mode, and the second operating mode is the detection mode.

2. The radar sensor assembly (1) according to claim 1, wherein, The microcontroller (8) is configured to: In the energy-saving mode, the transmitting circuit (3) is operated in the first transmit drive sequence of the transmitting antennas (4A, 4B, 4C), and In the detection mode, the transmitting circuit (3) is operated with the second transmission control sequence of the transmitting antennas (4A, 4B, 4C). The number of drive control processes triggered by the first launch drive control sequence is less than the number of drive control processes triggered by the second launch drive control sequence.

3. The radar sensor assembly (1) according to claim 2, wherein, The microcontroller (8) is configured to: in the energy-saving mode, sequentially not drive at least one of the plurality of transmit antennas (4A, 4B, 4C) during the first transmit drive sequence. Preferably, the microcontroller (8) is configured to: in the energy-saving mode, not drive at least one of the plurality of transmit antennas (4A, 4B, 4C) at each drive time point of the transmit drive sequence during the first transmit drive sequence.

4. The radar sensor assembly (1) according to claim 2 or claim 3, wherein, The microcontroller (8) is configured to sequentially drive exactly one of the transmitting antennas (4A, 4B, 4C) during the first transmit drive sequence in the energy-saving mode, preferably, each of the transmitting antennas has the same number of drive processes in a transmit drive sequence.

5. The radar sensor assembly (1) according to any one of the preceding claims, wherein, The microcontroller (8) is configured to: In the energy-saving mode, the receiving circuit (5) is operated in the first receiving drive sequence of the receiving antennas (6A, 6B, 6C, 6D), and In the detection mode, the receiving circuit (5) is operated with the second receiving drive sequence of the receiving antennas (6A, 6B, 6C, 6D). The number of drive control processes triggered by the first received drive control sequence is less than the number of drive control processes triggered by the second received drive control sequence.

6. The radar sensor assembly (1) according to claim 5, wherein, The microcontroller (8) is configured to: in the energy-saving mode, sequentially not drive at least one of the plurality of receiving antennas (6A, 6B, 6C, 6D) during the first receiving drive sequence; preferably, the microcontroller (8) is configured to: in the energy-saving mode, not drive at least one of the plurality of receiving antennas (6A, 6B, 6C, 6D) at each drive time point of the receiving drive sequence during the first receiving drive sequence.

7. The radar sensor assembly (1) according to claim 5 or claim 6, wherein, The microcontroller (8) is configured to sequentially drive exactly one of the receiving antennas (6A, 6B, 6C, 6D) during the first receiving drive sequence in the energy-saving mode, preferably, each of the receiving antennas (6A, 6B, 6C, 6D) has the same number of drive processes in a receiving drive sequence.

8. The radar sensor assembly (1) according to any one of the preceding claims, wherein, The drive control process in the first operating mode has a higher transmit power for a single driven antenna than the drive control process in the second operating mode. Preferably, the drive control process in the first operating mode has a higher transmit power for a single driven antenna than each drive control process in the second operating mode. Particularly preferably, each drive control process performed in the first operating mode has a higher transmit power for a single driven antenna compared to the case in the second operating mode.

9. The radar sensor assembly according to claim 8, wherein, In the first operating mode, the transmit drive sequence has at least one high-power drive, in which the transmit antenna is operated at a higher transmit power for a single driven antenna than that specified for a single driven antenna in each drive process in the second operating mode, preferably, the transmit drive sequence has exactly one such high-power drive.

10. The radar sensor assembly (1) according to any one of the preceding claims, wherein, Compared to the second operating mode, the drive and control process in the first operating mode has a smaller transmission frequency bandwidth. Preferably, each drive and control process performed in the first operating mode has a smaller transmission frequency bandwidth compared to the second operating mode.

11. The radar sensor assembly (1) according to any one of the preceding claims, wherein, The sampling rate for sampling the received signal is lower in the first operating mode compared to the second operating mode.

12. The radar sensor assembly (1) according to any one of the preceding claims, wherein, Multiple sampling rate schemes are stored in the storage device of the central control circuit, wherein the sampling rate depends on the parameters of the radar response, so that the sampling rate is selected based on the analysis of the radar response.

13. The radar sensor assembly (1) according to any one of the preceding claims, wherein, In the first operating mode, a different chirp is configured for each of the plurality of transmitting antennas to drive the transmitting antenna, and / or, wherein, In the second operating mode, a different chirp is configured for each of the plurality of transmitting antennas to drive the transmitting antenna.

14. The radar sensor assembly (1) according to any one of the preceding claims, wherein, In the first operating mode, the first chirp configuration is configured to drive the transmitting antenna, and In the second operating mode, the second chirp configuration is configured to drive the transmitting antenna.

15. The radar sensor assembly (1) according to claim 14, wherein, The first chirp configuration specifies that a drive process with higher transmit power and narrower transmit frequency bandwidth for a single driven antenna and a drive process with lower transmit power and wider transmit frequency bandwidth for a single driven antenna are performed alternately.

16. The radar sensor assembly (1) according to claim 14, wherein, The first chirp configuration specifies that a first drive control process with a first transmit frequency bandwidth and a first transmit power for a single driven antenna and a second drive control process with a second transmit frequency bandwidth and a second transmit power for a single driven antenna are performed alternately, wherein the second transmit power is zero watts or close to zero watts and the second transmit frequency bandwidth is zero hertz or close to zero hertz.

17. The radar sensor assembly (1) according to any one of the preceding claims, wherein, The microcontroller (8) is configured to: When the antenna assembly (2) is operating in the energy-saving mode, it retrieves and analyzes the radar response detected by the receiving circuit (5). When the analysis indicates that the predetermined criteria are met, the microcontroller (8) switches from the energy-saving mode to the detection mode.

18. The radar sensor assembly (1) according to claim 17, wherein, The predetermined standards include: The approach of an obstacle, the approach of a user, or the user's intention to open a door can be identified, for example, by whether the detected radar response matches an empirically determined characteristic radar response stored on the microcontroller or in a memory connected to the microcontroller.

19. The radar sensor assembly (1) according to any one of the preceding claims, characterized in that, The antenna assembly (2) and the control circuit (7) with microcontroller (8) are arranged on the same printed circuit board.

20. The radar sensor assembly (1) according to any one of the preceding claims, characterized in that, The antenna assembly (2) and the control circuit (7) with the microcontroller (8) are arranged on the same chip and form a system-on-a-chip.

21. A motor vehicle (9) comprising a radar sensor assembly according to any one of claims 1 to 20 for identifying objects.

22. The motor vehicle (9) according to claim 21, wherein, The radar sensor assembly is arranged in the door handle or in the pillar, or the radar sensor assembly is arranged in a design element, particularly in the B-pillar (10).

23. The motor vehicle (9) according to claim 21 or claim 22, wherein, The radar sensor assembly is connected to the controller (11) of the motor vehicle (9), wherein the motor vehicle (9) has a keyless vehicle access system for identifying an operator carrying a wireless ID transmitter (12), wherein the microcontroller (8) of the radar sensor assembly is configured to enter the detection mode only if the microcontroller (8) receives an acknowledgment signal from the controller during a predetermined time period to confirm that the ID transmitter (12) within the radio range has been successfully authenticated.

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