Method for operating a radar sensor device for a motor vehicle, radar sensor device, and motor vehicle

Abstract

The invention relates to a method for operating a radar sensor device (2) for a motor vehicle (1), comprising the steps of providing a first radar sensor unit (6) of the radar sensor device (2) having a first detection range (29); providing a second radar sensor unit (7) of the radar sensor device (2) having a second detection range, different from the first detection range (29); arranging first sensor elements (25) of the first radar sensor unit (6) alternately with second sensor elements (26) of the second radar sensor unit (7) on a component (28) of the motor vehicle (1), at least in certain regions; and, emitting first radar radiation (4) by means of the first sensor elements (25) and simultaneously emitting second radar radiation by means of the second sensor elements (26). The invention also relates to a radar sensor device (2) and to a motor vehicle (1).

Description

[0001] Description

[0002] Method for operating a radar sensor device for a motor vehicle, radar sensor device and motor vehicle

[0003] The invention relates to a method for operating a radar sensor device for a motor vehicle according to the applicable patent claim 1. Furthermore, the invention relates to a radar sensor device and a motor vehicle.

[0004] Due to physical relationships, the angular resolution of a radar system is determined by the size of its antenna aperture. Current radar systems are usually modules measuring approximately 10 x 10 cm. 2, limited by the ability to integrate into motor vehicles. The angular resolution is therefore limited to approximately 2 degrees at best. The resolution improves proportionally with the size of the aperture. If two objects are to be resolved in angles, especially azimuth and elevation, an aperture extended in two directions is required.

[0005] The second important parameter in an antenna array is the spacing between the elements. This determines the unambiguously measurable angular range. Larger antenna spacing leads to ambiguities, particularly so-called secondary peaks, in angle measurements. Modern automotive radar systems therefore use so-called virtual antenna elements. Such a virtual element is created by combining a transmitting antenna with a receiving channel, precisely at the center of the connection vector. With n transmitting antennas and m receiving antennas, a virtual array of a maximum of n x m elements can be created. This principle is also commonly known as multiple input multiple output (MIMO).

[0006] To detect the surroundings as reliably as possible, the sensor requires the highest possible signal-to-noise ratio and stable signal generation. This is particularly necessary for large apertures with a thinned antenna array to clearly detect targets. The design of an individual array is optimized for a specific application, such as Short Range Radar (SRR), Middle Range Radar (MRR), or Long Range Radar (LRR), so optimal target detection is not possible if the specific array is used in another application.

[0007] US 6 151 539 A describes an autonomous vehicle and a method for controlling the same, comprising an input unit for receiving one or more driving orders, a route planning unit containing at least one position determining device and a digital road map, a vehicle path generation unit, an array of sensors containing at least one distance sensor for detecting objects and at least one distance sensor for detecting status features of the route, a collision avoidance unit, a vehicle status detection unit, a vehicle control unit and a unit for controlling the vehicle actuator system on the basis of signals generated by the vehicle control unit, wherein the array of sensors comprises at least two substantially horizontally aligned distance sensors at the front of the vehicle, at least one distance sensor in the rear area of ​​the vehicle, at least one trackable,a distance sensor on the roof of the vehicle directed towards the roadway, ultrasonic sensors and / or microwave radar sensors arranged on each side of the vehicle, and at least one camera located in the front and rear of the vehicle.

[0008] US 2007 156286 A1 describes a mobile robot with a rangefinder and a stereo vision system. The mobile robot is capable of autonomously navigating urban terrain, creating a map based on the rangefinder data, and communicating the map to the operator during multiple operator-selectable exploration operations. The mobile robot uses a U-transform technique to identify linear features in its environment and then orients itself to the identified linear features to navigate through the urban terrain. At the same time, a scaled vector field histogram technique is applied to the combination of rangefinder and stereo image data to detect and avoid obstacles encountered by the mobile robot during outdoor navigation.Additionally, the missions performed by the mobile robot may include constraint parameters based on distance traveled or elapsed time to ensure the completion of autonomous operations. US 2012 154 785 A1 describes a vehicle collision avoidance system comprising a system controller, a pulsed laser transmitter, an array of independent lidar sensor units, a cabling infrastructure, internal memory, a scene processor, and a data communication port. The described invention is capable of developing a 3D scene into object data for targets within the scene from multiple lidar sensor units coupled to a centralized lidar-based collision avoidance system. The key lidar elements are integrated into standard headlight and taillight assemblies.Articulated lidar sensors capture the terrain that comes into view around a bend, at the crest of a hill, or at the bottom of a valley. A central laser transmitter can be split into multiple optical outputs and routed through fibers to illuminate portions of the 360° field of view around the vehicle. The fibers can also serve as amplifiers to increase the optical intensity delivered by a single main laser.

[0009] The object of the present invention is to provide a method, a radar sensor device and a motor vehicle by means of which an environment of the motor vehicle can be detected in an improved manner.

[0010] This object is achieved by a method, a radar sensor device, and a motor vehicle according to the independent patent claims. Advantageous embodiments are specified in the subclaims.

[0011] One aspect of the invention relates to a method for operating a radar sensor device for a motor vehicle. A first radar sensor device of the radar sensor device is provided with a first detection range, and a second radar sensor device of the radar sensor device is provided with a second detection range of the radar sensor device that differs from the first detection range. First sensor elements of the first radar sensor device are arranged, at least in some regions, alternately with second sensor elements of the second radar sensor device on a component of the motor vehicle, and first radar radiation is emitted by means of the first sensor elements and simultaneously second radar radiation is emitted by means of the second sensor elements.

[0012] In particular, this allows for improved detection of the surroundings of the motor vehicle. In particular, this allows for improved resolution in the relevant field of view, especially in the so-called field of view (FoV). Furthermore, increased accuracy in target detection can be achieved. In particular, the radar sensor device can thus provide simultaneous short-range radar, middle-range radar, and long-range radar in a single radar sensor device. Furthermore, redundancies can be incorporated to protect against damage to / failure of individual antenna elements or sensor elements.

[0013] In particular, “alternately arranged” means that, for example, a first antenna element of the first radar sensor device is arranged on the component, for example on a shock absorber of the motor vehicle. A sensor element of the second radar sensor device can then be arranged thereafter. A sensor element of the first radar sensor device can then, in turn, be arranged thereafter, and so on. The sensor elements of the first radar sensor device do not have to have the same number of sensor elements as the sensor elements of the second radar sensor device. In particular, in the present case, the sensor elements on the shock absorber are to be arranged essentially in the transverse direction of the vehicle. It is of course also possible for the sensor elements to be arranged in the vertical direction, for example on a tall pillar of the motor vehicle.

[0014] According to an advantageous embodiment, the first radar sensor device is provided as a short-range radar, and the second radar sensor device is provided as a long-range radar. Alternatively, a radar sensor device can also be provided as a medium-range radar. In particular, joint transmission can generate a radar beam with improved detection. It is also possible for the two radar sensor devices to be operated independently of one another in a different operating mode, rather than simultaneously. Thus, an improved radar sensor device can be provided, which in particular improves environmental detection.

[0015] A further advantageous embodiment provides that each sensor element is provided as an electronic-photonic co-integrated chip. In particular, a miniaturized photonic co-integrated chip can thus be integrated into a coherently distributed, thinned array, which is provided, in particular, over a large area on the motor vehicle. In this case, cohesion of the optically transmitted radar signal on the electronic-photonic co-integrated semiconductor circuit can be realized in at least two different frequencies. In particular, the generation of an FMCW signal as well as the entire signal processing or evaluation is carried out by a central station of the radar sensor device. Each transmitting and receiving module, in other words, each sensor element, can in particular be formed from an electronic-photonic co-integrated chip, in particular a so-called EPIC chip.Silicon photonics technology, for example, is used for cointegration. This enables the monolithic integration of photonic components, high-frequency electronics, and digital electronics on a single chip. The technical innovation of such a chip lies in particular in what is known as signal transmission of, for example, gigahertz signals using an optical carrier signal in the terahertz range. The central station generates an optical carrier frequency. The signal to be transmitted is modulated onto this frequency at one-eighth of the radar frequency and sent via optical fiber to the antenna chips or sensor elements. The frequency is multiplied eightfold at these, allowing the radar radiation to be emitted by the antenna chips. Signal detection occurs in the opposite direction. Thus, reliable environmental detection can be realized using the electronic-photonic cointegrated chips.

[0016] It is further advantageous if the radar sensor devices are provided in a bumper of the motor vehicle and / or a glass device of the motor vehicle and / or a roof device of the motor vehicle. In particular, the radar sensor devices can also be provided on other components of the motor vehicle. In particular, 360° environmental detection can thus be realized. Of course, other installation locations are also possible, such as a door of the motor vehicle, door handles, sills, ABC pillars, or the like. Thus, reliable environmental detection of the motor vehicle can be carried out based on the radar sensor devices.

[0017] A further advantageous embodiment provides that radar radiation is emitted by means of a sensor element and reflected radar radiation is received. In other words, a sensor element can be designed as both a transmitting antenna and a receiving antenna. In particular, the combination of an electronic-photonic co-integrated chip has the advantage that the sensor elements can be made essentially very small and, at the same time, environmental detection can be advantageously realized. Furthermore, it has proven advantageous if, in order to generate radar radiation by means of one of the radar sensor devices, a respective optical carrier signal is generated by means of a respective electronic computing device and the optical carrier signal is transmitted to the sensor elements. The carrier signal can thus be transmitted to the sensor elements via an optical fiber.

[0018] A further advantageous embodiment provides for the optical carrier signal to be transmitted to the sensor elements by means of a gigahertz synthesis unit. In particular, the optical carrier signal is converted into a gigahertz spectrum by the gigahertz synthesis unit, and the optical carrier signal is generated in the terahertz frequency range. It can then be provided that one-eighth of the radar frequency is modulated onto the optical carrier signal by means of the gigahertz synthesis unit. This allows for simple monitoring of the environment.

[0019] Furthermore, it has proven advantageous to use the radar sensor device to detect the vehicle's surroundings. For example, object detection can also be performed based on the radar sensor device. This makes it possible to monitor the vehicle's surroundings.

[0020] It is also advantageous if the first radar sensor device is provided with a higher number of first sensor elements than the second radar sensor device.

[0021] In particular, the number of sensor elements is provided depending on which radar radiation is to be emitted by the first radar sensor device and the second radar sensor device. The same number of sensor elements can also be provided by the first radar sensor device and the second radar sensor device. This allows for improved emission of a radar sensor beam.

[0022] It is also advantageous if the first radar radiation and the second radar radiation are emitted in response to a control signal. Thus, in particular, a first operating mode can be provided in which the first radar radiation and the second radar radiation are emitted essentially simultaneously in order to be able to carry out the previously described method accordingly.

[0023] It can further be provided that, depending on a further control signal, the first radar radiation and the second radar radiation are emitted independently of one another. Thus, the radar sensor device can be operated in a second operating mode in which the first radar radiation and the second radar radiation are emitted, in particular independently of one another in terms of time. Thus, an additional operating mode can be provided in which the radar sensor devices can be operated independently of one another. The radar sensor device can thus be operated with great flexibility.

[0024] It is also advantageous if the first sensor elements are provided with a different shape than the second sensor elements. For example, the sensor elements can have different sizes. Thus, different transmission characteristics can be provided based on the different sensor elements.

[0025] A further aspect of the invention relates to a radar sensor device having at least a first radar sensor device and a second radar sensor device, wherein the radar sensor device is designed to carry out a method according to the preceding aspect. In particular, the method is carried out using the radar sensor device.

[0026] Yet another aspect of the invention relates to a motor vehicle having at least one radar sensor device according to the preceding aspect.

[0027] For example, the motor vehicle can be provided in a substantially at least partially automated or fully automated manner.

[0028] Advantageous embodiments of the method are to be regarded as advantageous embodiments of the radar sensor device and the motor vehicle. The radar sensor device and the motor vehicle, in particular, have specific features for carrying out corresponding method steps.

[0029] The invention also includes further developments of the radar sensor device according to the invention and of the motor vehicle according to the invention, which have features as already described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the radar sensor device according to the invention and of the motor vehicle according to the invention are not described again here. The invention also encompasses combinations of the features of the described embodiments.

[0030] For use cases or application situations that may arise during the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and / or a request to enter user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0031] Exemplary embodiments of the invention are described below. Shown are:

[0032] Fig. 1 is a schematic perspective view of an embodiment of a motor vehicle with an embodiment of a radar sensor device;

[0033] Fig. 2 is a schematic block diagram according to an embodiment of a radar sensor device;

[0034] Fig. 3 is a schematic block diagram according to an embodiment of a radar sensor device; and

[0035] Fig. 4 is a further schematic block diagram of an embodiment of a radar sensor device.

[0036] The exemplary embodiments explained below are preferred exemplary embodiments of the invention. In the exemplary embodiments, the described components each represent individual, independently considered features of the invention, which also further develop the invention independently of one another and are thus also to be considered as components of the invention, either individually or in a combination other than that shown. Furthermore, the described exemplary embodiments can also be supplemented by further features of the invention already described.

[0037] In the figures, functionally identical elements are provided with the same reference numerals.

[0038] Fig. 1 shows a schematic perspective view of an embodiment of a motor vehicle 1 with an embodiment of a radar sensor device 2. The radar sensor device 2 is designed to detect an environment 3 of the motor vehicle 1. In particular, Fig. 1 shows that the radar sensor device 2 is designed to emit at least a first radar radiation 4. Furthermore, Fig. 1 shows a jointly emitted radar radiation 5, which is generated in particular based on the method described below.

[0039] Fig. 2 shows in particular a schematic block diagram according to an embodiment of a radar sensor device 2 or at least one radar sensor device 6, 7 (Fig. 3) of the radar sensor device 2.

[0040] The following exemplary embodiment shows, in particular, that the method can be implemented on the basis of electronic-photonic co-integrated chips 8. In particular, the electronic-photonic co-integrated chips 8, which can also be referred to as EPIC chips, are provided as sensor elements 9.

[0041] Fig. 2 shows in particular that the radar sensor devices 6, 7 have at least one central station 10. The central station 10 has at least one processor device 11 and a control interface 12. Furthermore, a row waveguide grating 13 is optionally shown. Furthermore, a low-level signal processor unit 14 is optionally shown. Furthermore, a digital interface 15, for example in the form of an analog-to-digital converter, is shown. The elements presented are in particular electronic elements. Furthermore, the central station 10 also has photonic components. For example, a feedback loop 16 can optionally be provided here. Furthermore, a laser device 17, a gigahertz synthesis unit 18, an optical control unit 19, an optical switch 20 and an optical detection device 21 are shown.In particular, corresponding optical signals 22 are sent from the optical switch 20 to the EPIC chips 8. Optical return signals 23 are, in turn, sent from the EPIC chips 8 to the optical detection unit 21. Furthermore, an electronic output signal 24 to the EPIC chips 8 is also shown.

[0042] In particular, Fig. 3 shows the central station 10 with transmitter and receiver chips on the right side in a co-integrated design. In the electronic-photonic integrated circuits, in particular the EPIC chips 8, the photonic components, such as the grating coupler and the photodiode for the transmitter, as well as two grating couplers, a photodiode, and a modulator for the receiver, are shown, while the electronic components are preferably shown on the left side. The central station 10 generates an optical carrier signal. This is fed into the gigahertz synthesis unit 18, and the synthesized gigahertz signal is transmitted via fiber in the optical spectral range to the EPIC chips 8, for example, to be emitted as a 77 gigahertz signal. Signal detection occurs in the reverse direction. All data is processed on the central station 10.

[0043] Fig. 3 shows a schematic view of an embodiment of the radar sensor device 2. In the following exemplary embodiment, it is shown in particular that the radar sensor device 2 can have a first radar sensor device 6 and a second radar sensor device 7. It is further shown that the radar sensor devices 6, 7 can have different sensor elements 25, 26. For example, the first radar sensor device 6 has first sensor elements 25 for emitting first radar radiation 4, and the second radar sensor device 7 has second radar sensor elements 26 for emitting second radar radiation. In particular, it is shown here that the radar sensor elements 25, 26 are arranged essentially alternately, at least in a partial region 27. In other words, a first sensor element 25 is adjacent to a second sensor element 26, wherein the second sensor element 26 is in turn adjacent to a first sensor element 25.

[0044] Furthermore, a component 28 of the motor vehicle 1 is shown, for example, in which the sensor elements 25, 26 are arranged. The component 28 can be, for example, a shock absorber or bumper, a glass device, or a roof device.

[0045] Fig. 3 shows in particular the method for operating the radar sensor device 2. The first radar sensor device 6 is provided with a first detection range 29. The second radar sensor device 7 is provided with a second detection range that is different from the first detection range 29. The first sensor elements 25 of the first radar sensor device 6 are arranged alternately with the second sensor elements 26 of the second radar sensor device 7, at least in some areas. The first radar radiation 4 is emitted by means of the first sensor elements 25 and the second radar radiation is emitted simultaneously by means of the second sensor elements 26, so that a common range 30 is achieved.

[0046] For example, it can be provided that the first radar sensor device 6 is provided as a short-range radar and the second radar sensor device 7 is provided as a long-range radar. Furthermore, it can be provided that radar radiation is emitted and reflected radar radiation is received by means of a sensor element 25, 26, whereby the sensor element 25, 26 is thus essentially designed as a transmitting antenna and a receiving antenna.

[0047] Furthermore, Fig. 3 shows that, for example, the first radar sensor device 6 is provided with a higher number of sensor elements 25 than the second radar sensor device 7.

[0048] Fig. 4 shows a further schematic view according to an embodiment of the radar sensor device 2. In the present case, the embodiment from Fig. 3 is shown in particular. In particular, an outer emission lobe 31 is shown, which is generated when the sensor elements 25, 26 are operated simultaneously. In particular, a first operating mode can be provided by means of the radar sensor device 2, in which the sensor elements 25, 26 emit simultaneously. This occurs in particular as a function of a control signal for the corresponding radar sensor device 2 or for the radar sensor devices 6, 7. It is also possible to provide a second operating mode, wherein the first radar radiation 4 and the second radar radiation are again operated independently of one another as a function of a further control signal.

[0049] Furthermore, Fig. 4 shows that the first sensor elements 25 are provided with a different shape than the second sensor elements 26. Overall, Figs. 1 to 4 thus show that a fully coherent sensor can be distributed three-dimensionally and in a 360° dimension around the motor vehicle 1. Additional positioning of antennas and photonic chips in the original array can be realized alongside it. The antennas can be shaped differently to cover additional sensor modalities. Online switching of individual / multiple antenna elements and chips from the second array, in other words the second radar sensor device 7, can be realized in order to obtain a desired array pattern, such as from short-range radar to long-range radar. The target, in particular an object in the environment 3, is then detected, and the corresponding targets, for example the distance to it, are calculated.This can, in turn, be passed on to a higher-level environment model. Reference symbol list.

[0050] motor vehicle

[0051] Radar sensor device

[0052] Environment first radar radiation common radar radiation first radar sensor device second radar sensor device

[0053] Epic chip

[0054] Sensor elements

[0055] Central station

[0056] Processor setup

[0057] Control interface

[0058] Line waveguide grating

[0059] Low-level signal processor device

[0060] Digital interface

[0061] Feedback Loop

[0062] Laser

[0063] Gigahertz synthesis unit optical control device optical switch optical detection device optical output signal optical input signal electronic output signal first sensor elements second sensor elements

[0064] Sub-area

[0065] Component first detection range common detection range radar lobe

Claims

Patent claims 1. A method for operating a radar sensor device (2) for a motor vehicle (1), comprising the steps: Providing a first radar sensor device (6) of the radar sensor apparatus (2) with a first detection range (29); Providing a second radar sensor device (7) of the radar sensor device (2) with a second detection range different from the first detection range (29); At least partially alternating arrangement of first sensor elements (25) of the first radar sensor device (6) with second sensor elements (26) of the second radar sensor device (7) on a component (28) of the motor vehicle (1); and - Emitting first radar radiation (4) by means of the first sensor elements (25) and simultaneously emitting second radar radiation by means of the second sensor elements (26).

2. Method according to claim 1, characterized in that the first radar sensor device (6) is provided as a short-range radar and the second radar sensor device (7) is provided as a long-range radar.

3. Method according to claim 1 or 2, characterized in that a respective sensor element (25, 26) is provided as an electronic-photonic co-integrated chip (8).

4. Method according to one of the preceding claims, characterized in that the radar sensor devices (6, 7) are provided in a bumper of the motor vehicle (1) and / or a glass device of the motor vehicle (1) and / or a roof device of the motor vehicle (1).

5. Method according to one of the preceding claims, characterized in that radar radiation is emitted by means of a sensor element (25, 26) and reflected radar radiation is received.

6. Method according to one of the preceding claims, characterized in that in order to generate a radar radiation by means of one of the radar sensor devices (6, 7), a respective optical carrier signal is generated by means of a respective electronic computing device and the optical carrier signal is transmitted to the sensor elements (25, 26).

7. Method according to claim 6, characterized in that the optical carrier signal is transmitted to the sensor elements (25, 26) by means of a gigahertz synthesis unit (18).

8. Method according to one of the preceding claims, characterized in that an environmental detection for the motor vehicle (1) is carried out by means of the radar sensor device (2).

9. Method according to one of the preceding claims, characterized in that the first radar sensor device (6) is provided with a higher number of first sensor elements (25) than the second radar sensor device (7).

10. Method according to one of the preceding claims, characterized in that the first radar radiation (4) and the second radar radiation are emitted as a function of a control signal.

11. Method according to claim 10, characterized in that the first radar radiation (4) and the second radar radiation are emitted independently of one another in dependence on a further control signal.

12. Method according to one of the preceding claims, characterized in that the first sensor elements (25) are provided with a different shape than the second sensor elements (26).

13. Radar sensor device (2) with at least a first radar sensor device (6) and a second radar sensor device (7), wherein the radar sensor device (2) is designed to carry out a method according to one of claims 1 to 12.

14. Motor vehicle (1) with at least one radar sensor device (2) according to claim 13.

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