Method for determining at least one target information of a target object of a sensor system based on an environmental reconstruction of an environment of the sensor system, as well as sensor system and vehicle

Abstract

The invention relates to a method for determining at least one item of target information of a target object of a sensor system (2) which has a plurality of transmitting antennas (3) and a plurality of receiving antennas (4), wherein - in one transmission process, several electrical transmission signals (40 to 43) with different frequencies are transmitted simultaneously from the several transmission antennas (3) into an environment (18), - electrical reception signals (54 to 57) based on the transmitted electrical transmission signals (40 to 43) are received by the plurality of reception antennas (4), - on the basis of the received electrical reception signals (54 to 57), antenna positions of the plurality of transmitting antennas (3) and antenna positions of the plurality of receiving antennas (4), a virtual antenna array (39) having a plurality of virtual receiving antennas (61) is generated, - an environmental reconstruction of the environment (18) is carried out on the basis of the virtual antenna array (39), and - at least one target information is determined on the basis of the environmental reconstruction. Furthermore, the invention relates to a sensor system (2) and a vehicle (1).

Description

[0001] The present invention relates to a method for determining at least one item of target information of a target object using a sensor system which has a plurality of transmitting elements and a plurality of receiving elements.

[0002] Furthermore, the invention relates to a sensor system with a plurality of transmitting antennas, a plurality of receiving antennas and an electronic computing device.

[0003] Furthermore, the invention relates to a vehicle with a corresponding sensor system.

[0004] For example, WO 2022 / 228916 A1 discloses a radar sensor device configured as a single-chip system. A transmit path of the sensor device, a receive path of the radar sensor device, an optical input of the transmit device, an optical output, an antenna, and a digital interface unit of the radar sensor device are arranged on the single-chip system.

[0005] Furthermore, DE 10 2022 202028 A discloses a radar sensor device for a vehicle. This device comprises a transmitting device for transmitting radar transmission signals and a receiving device for receiving reception signals. The radar sensor device has at least one antenna structure, which has two opposing and spaced-apart metallic structural elements, where both of them are at least one antenna structure, which generates the electrical radar transmission signal and modulates the received electrical reception signal depending on the metallic structural elements.

[0006] Furthermore, US 10,686,523 B1 discloses a photonic integrated circuit which has both optical and electrical components to perform optical and electrical signal processing

[0007] An object of the present invention is to improve the detection of a target object in the environment of a sensor system by determining more comprehensive information regarding the target object and the environment.

[0008] This problem is solved by a method, a sensor system, and a vehicle according to the independent patent claims. Useful further developments arise from the dependent patent claims.

[0009] One aspect of the invention relates to a method for determining at least one item of target information of a target object of a sensor system having a plurality of transmitting antennas and a plurality of receiving antennas, wherein - In particular, in one transmission process, several electrical transmission signals with different frequencies are transmitted simultaneously from the several transmitting antennas into an environment, - In particular, electrical reception signals based on the transmitted electrical transmission signals are received by the plurality of receiving antennas, - In particular, based on the received electrical reception signals, antenna positions of the plurality of transmitting antennas and antenna positions of the plurality of receiving antennas, a virtual antenna array is generated, which has a plurality of virtual receiving antennas and a plurality of virtual receiving antennas, - In particular, an environmental reconstruction of the environment is carried out based on the virtual antenna array, and - In particular, at least one target information is determined on the basis of the environmental reconstruction.

[0010] The proposed method allows a sensor system to be used more efficiently and, in particular, more versatilely, since target information about a target object in the sensor system's environment can be acquired better and, in particular, more precisely. The virtual antenna array can be generated by simultaneously transmitting or emitting multiple frequency-shifted electrical transmission signals into the environment per transmission request. In other words, for each transmission process, the sensor system emits one electrical transmission signal each with several or a predetermined number of transmission antennas, i.e., transmission elements. These electrical transmission signals have different frequencies from one another, so that the electrical transmission signals are frequency-shifted from one another.Through the simultaneous transmission or emission of the frequency-shifted electrical transmission signals, an improved and, in particular, more efficient generation of a virtual antenna array can be achieved. The generation of virtual antenna arrays is particularly advantageous for signal processing and thus for environmental detection.

[0011] Based on the transmitted and received signals, several virtual antenna elements or a virtual antenna array can be set up, so that, for example, the resolution of the sensor system can be increased.

[0012] The electrical transmission signals emitted in the vicinity of the transmission system can in turn be reflected or re-radiated accordingly, so that at least some electrical reception signals corresponding to the electrical transmission signals can be received by several or at least some of the several reception antennas.

[0013] For the generation or creation of the virtual antenna array, particularly on the system side, the received electrical signals, the respective real antenna positions of the multiple, particularly real, transmitting antennas, and the real antenna positions of the multiple, particularly real, receiving antennas can be taken into account.

[0014] The virtual antenna array offers the primary advantage that, compared to the area antennas of a real antenna array of the sensor system, the virtual antenna array can have more transmitting antennas and more receiving antennas. Thus, the number of virtual transmitting antennas and virtual receiving antennas is greater, in particular many times greater, than the number of real transmitting antennas and real receiving antennas. This makes it easier and, in particular, more cost-effective to use and manufacture the real sensor system. It can now be manufactured to obtain more comprehensive information regarding the target object, in particular regarding the environment, and, for example, to expand the information content of target information regarding potential target objects. The virtual antenna array, in particular the more detailed ones, can be used to reconstruct the environment.For this purpose, in addition to the single transmission process, a multitude of consecutive transmission processes and the corresponding transmitted and received signals can be taken into account. This allows, above all, the detection of the spatial extent of the target object in the environment, such as in a vehicle environment when the sensor system is used in the automotive sector. Through environmental reconstruction, i.e., a virtual three-dimensional modeling of the environment based on the virtual antenna array, reliable detection of extended structures, such as target objects, in the vicinity of the sensor system can be carried out. Through environmental reconstruction, for example, a height profile of these structures, such as the target object, can be better estimated.

[0015] In particular, the present method offers advantages in increasing the comfort of the sensing process and, for example, improving the reliability of the sensor system, regardless of the weather conditions in the sensor system's vicinity. The virtual antenna array and the resulting environmental reconstructions enable robust environmental sensing for mapping and localization. By simultaneously simulating signals with excessive frequency shifts and the resulting virtual antenna array, descriptors can be detected within a three-dimensional environmental model, such as the environmental reconstruction, for mapping and localization.

[0016] The proposed method is particularly useful when the sensor system is used in the automotive sector. There, the sensor system can be used primarily to detect objects located next to a moving vehicle, i.e., while the vehicle is in motion. Using the proposed method, the transmitting and receiving antennas can be arranged on the side of the vehicle, for example, along the B-pillar. This allows for improved environmental detection by radiating radiation from the side of the vehicle, i.e., toward the passenger side and the front.

[0017] For environmental reconstruction, i.e., the modeling of a three-dimensional virtual environment based on the real environment, the simultaneous transmission of frequency-shifted transmission signals can be carried out at specific intervals during the vehicle's movement. This allows for continuous environmental detection using one or more virtual antenna arrays. This allows for a reconstruction of the environment. Based on this environmental reconstruction or the reconstructed environment, target objects located there can be detected more accurately and precisely, so that the information content of the target, such as a radar target, can be expanded or made more comprehensive.

[0018] In one embodiment, it is provided that a respective received electrical reception signal, which is assigned to a respective virtual reception antenna of the virtual antenna array, is mixed with a carrier signal on which the plurality of mutually frequency-shifted electrical transmission signals pass. In other words, the electrical reception signal relating to the associated reception antennas is mixed with the original transmission signal, i.e. in particular the electrical carrier signal. Based on the carrier signal, which can be provided by a central computing device of the sensor system, the mutually frequency-shifted electrical transmission signals can be generated. In other words, the respective reception signal can be mixed by multiplying it by the original transmission signal, i.e. the carrier signal.Thus, a corresponding mixed signal, such as a beat signal, can be generated, which is required for the calculation of the virtual antenna array and in particular for the environmental reconstruction.

[0019] In one embodiment, a distance spectrum is determined for each virtual receiving antenna based on the received signal associated with the respective receiving antenna and mixed with the carrier signal. Using this distance spectrum, which can also be referred to as a "range spectrum," distance information can be generated or calculated for a respective virtual receiving antenna based on the mixed received signal. In particular, a respective distance spectrum can be generated for each virtual receiving antenna. Thus, corresponding distance information regarding a respective virtual receiving antenna can be provided.

[0020] In one embodiment, it is provided that a respective distance spectrum of a respective virtual receiving antenna is decomposed into partial spectra depending on a transmitted electrical transmission signal corresponding to the reception rules and the transmitter antenna transmitted by this electrical transmission signal. This allows a decomposition of the distance spectrum depending on the corresponding real transmitting antenna. Thus, a selection is made based on the real transmitting antenna and, in particular, the frequency deviations of the respective transmitter antenna. This is because the transmitting antennas transmit electrical transmission signals that are frequency-shifted relative to one another, so that a respective signal is transmitted between two transmitting antennas that experiences or has a frequency deviation compared to the others.This allows the frequency spectrum of each virtual receiving antenna to be selected based on the respective real transmitting antenna that emitted the corresponding signal. This is particularly advantageous for environmental reconstruction and, in particular, for three-dimensional environmental modulation.

[0021] In one embodiment, it is provided that the partial spectra of a respective virtual receiving antenna are also projected onto a virtual, spatial grid model relating to the environmental reconstruction, with which the environment can be modeled three-dimensionally, the dependence on the transmitting antenna corresponding to a respective partial spectrum of the partial spectra. In other words, a spatial grid model can also be implemented here by projecting the partial spectra of a respective virtual receiving antenna. For example, a position can be defined as the starting point for a respective transmission process. This position can in turn be used as a reference for generating the virtual spatial grid model. In other words, a virtual or software-based modulation or reconstruction of the environment can be carried out with the aid of the grid model.Thus, on the system side, target objects can be projected into the spatial grid model based on the received signals and the corresponding partial spectra, which may contain distance information regarding the target object.

[0022] Based on the various partial spectra, the spatial extent of the target object can be characterized or provided. This is particularly advantageous for determining target information, as it allows for the determination of more comprehensive information regarding the environment and, in particular, the target object or multiple target objects. For example, the partial spectra of each virtual receiving antenna can be projected onto a discrete, three-dimensional volume grid, such as the virtual spatial grid model, depending on the transmitting antenna corresponding to the respective partial spectrum. This can be advantageously used for environmental reconstruction.In one embodiment, the virtual spatial grid model is divided into multiple volume pixels, with a respective partial spectrum of the partial spectra being assigned to a respective virtual receiving antenna based on a relationship between the corresponding transmitting antenna and the virtual spatial grid model, to a volume pixel of the multiple volume pixels. Based on the respective partial spectra, which contain distance information, a respective volume pixel can be provided or filled with information. In other words, each volume pixel of the grid model contains corresponding information, so that corresponding information regarding the target object can be determined.

[0023] For example, the grid model can be square, so that the respective volume pixels can be cuboid-shaped. Depending on the grid model in question, in particular depending on the environment, any number of volume pixels can be combined to generate the grid model. Thus, depending on the virtual antenna array, at least some of the volume pixels can be provided with corresponding information regarding the environment detection and, in particular, the target direction.

[0024] In one embodiment, phase compensation filtering is performed for a respective sub-spectrum to compensate for a phase position of the respective sub-spectrum in the virtual, spatial peak model. The phase bundle compensation filtering of a respective sub-spectrum is performed based on the transmitting antenna of the virtual receiving antenna of the respective sub-spectrum corresponding to the respective sub-spectrum and a frequency of the electrical transmission signal emitted by the transmitting antenna corresponding to the respective sub-spectrum. Thus, a respective sub-spectrum can be filtered so that a compensation of a respective phase position or phase can be performed.For filtering, the transmitting antenna corresponding to the partial spectrum, the virtual receiving antenna of the partial spectrum, and the frequency of the electrical signal emitted by the corresponding transmitting antenna can be taken into account. In particular, phase compensation filtering can compensate for distance-related phase shifts in the projected or projected partial spectrum on the grid model. This allows for more efficient environmental modeling or reconstruction.

[0025] One embodiment provides for the integration of the individual partial spectra of a respective receiving antenna, to which phase compensation filtering has been performed. This results in the integration of the filtered projections of all partial spectra. This allows, for example, a filtered data structure to be assigned to a respective receiving antenna, which corresponds, for example, to a measurement position and the spatial grid model or grid model at this measurement position.

[0026] A further aspect of the invention relates to a sensor system with a plurality of transmitting antennas, a plurality of receiving antennas, and an electronic computing device, wherein the sensor system is designed to carry out or execute a method according to the preceding aspect or an advantageous development thereof. Thus, the method mentioned above can be carried out with the sensor system just described.

[0027] With the help of the sensor system, for example, an environmental reconstruction, particularly a three-dimensional environmental reconstruction, of the sensor system's environment can be performed. In particular, for the reconstruction of the environment, a synthetic aperture can be constructed and the received signals can be reconstructed using a virtual antenna array.

[0028] In particular, the sensor system can be used to perform frequency conversion of a terahertz carrier signal into the gigahertz frequency range after optical signal transmission and, conversely, reception of gigahertz signals with modulation on terahertz carrier signal.

[0029] In particular, the proposed sensor system can be used in motor vehicles. In particular, the sensor system can be used, for example, in at least partially autonomously operated motor vehicles, especially in fully autonomously operated motor vehicles. Such automated driving requires reliable environmental perception, which can be achieved by the sensor system. The environment can be detected using sensors such as radar, lidar, and cameras. These could be examples of the sensor system's application areas. The sensor system can perform a holistic 360-degree three-dimensional detection of the environment, allowing all static and dynamic objects to be detected.

[0030] The sensor system can, for example, be used to improve environmental detection regarding the side areas of a vehicle.

[0031] The sensor system can be used as an alternative to Lidar, since Lidar in particular plays a key role in redundant, robust environment detection, as this type of sensor can measure distances and angles more precisely in environment detection and can also be used for classification.

[0032] In particular, the sensor system can be used in at least partially autonomous vehicles, but especially in fully autonomous vehicles. However, to enable such automated driving, reliable environmental perception is essential. The environment is recorded using sensors such as radar, lidar, or cameras. A holistic 360-degree three-dimensional recording of the environment is particularly important so that all static and dynamic objects can be detected. The sensor system can be used for this purpose. In particular, lidar plays a key role in redundant, robust environment detection, as this type of sensor can measure distances more precisely in environment detection and can also be used for classification. However, these lidar sensors are cost-intensive and their construction complex.360-degree three-dimensional environment detection is particularly problematic, as it requires either many smaller individual sensors, which typically operate with many individual light sources and detector elements, or large lidar sensors. Furthermore, lidar sensors are susceptible to weather influences such as rain, fog, or direct sunlight. This sensor system can remedy this.

[0033] Radar sensors and sensor systems are also established in automotive engineering and deliver reliable and fail-safe data in all weather conditions. Even poor visibility conditions, such as rain, fog, snow, dust, or darkness, barely affect their detection reliability. However, the current state of the art has limited resolution; in particular, standard radars currently in use are only designed with an angular resolution of approximately 2 degrees. To meet the requirements for increased automation in automotive engineering with safe driving functions, the sensor system is designed to deliver three-dimensional images with a high angular resolution in the range of 0.1 degrees and below, with high immunity to disturbances from their surroundings.This cannot be achieved with conventional radar technology according to the state of the art, as the resolution of such systems is too low. The sensor system according to the invention advantageously intervenes precisely in this area.

[0034] The sensor system can be designed as a photonic radar sensor device, which achieves an increase in resolution by cointegrating electronic and photonic components into a single semiconductor chip. The tracking of an FMCW signal as well as all signal processing and evaluation are performed at the central station. Each transmit and receive module has an electronic-photonic cointegrated chip, a so-called EPIC chip. Silicon photonics technology is used for the cointegration. This enables the monolithic integration of photonic components, radio-frequency electronics, and digital electronics together on a single chip. The technical innovation of such a system lies in the signal transmission of gigahertz signals using the optical carrier signal in the terahertz frequency range.A central station, which can also be referred to as a central electronic processing unit, generates an optical carrier frequency in terahertz. The transmitted signal is modulated at one-eighth the radar frequency and sent via the optical fiber to the antenna chips. Frequency multiplication occurs there, allowing the radar radiation to be emitted by the antenna chips. Signal detection occurs in the opposite direction. All data is processed at the central station.

[0035] However, such a design is very complex in the implementation of gigahertz electronics at the chip level. In particular, the on-chip frequency multiplication following detection by a photodiode is technically challenging and poses a significant challenge with regard to gigahertz signal generation with a high signal-to-noise ratio and the lowest possible jitter. The gigahertz signal must be extensively stabilized in subsequent steps. Furthermore, gigahertz electronics are cost-intensive. Furthermore, high performance requirements are placed on the optical carrier, especially the laser, since a high level of optical power is required to generate a high-precision gigahertz signal, making single-phase loops difficult to implement for a radar array with many distributed radar semiconductor chips.In particular, two photonic-electronic semiconductor chips are still required for each transmit and receive channel, which leads to additional costs. The above-mentioned problems are at least partially, and in particular completely, solved by the sensor system according to the invention.

[0036] In particular, the invention utilizes an optical interface to couple the radiation of the laser device, which can also be configured as a CW laser, into a photonic semiconductor. This can be the optical transmission signal or a carrier signal of the CW laser.

[0037] The generation of the FMCW signal, as well as all signal processing and evaluation, are carried out by a central station, for example, the computer. Each transmit and receive module consists of an electronic-photonic cointegrated chip (so-called "EPIC chip"), and silicon photonics technology is used for cointegration. This enables the monolithic integration of photonic components, radio-frequency electronics, and digital electronics on a single chip ("electronic-photonic cointegration"). The technical innovation of such a system lies in the signal transmission of GHz signals using an optical carrier signal in the THz frequency range. A central station generates an optical carrier frequency (THz). The signal to be transmitted is modulated onto this frequency at 1 / 8 of the radar frequency and sent to the antenna chips via optical fiber.The frequency is multiplied eightfold on these, allowing the radar radiation to be emitted by the antenna chips. Signal detection occurs in the opposite direction. All data is processed at the central station.

[0038] The principle of electronic-photonic cointegration in a single chip, with silicon-on-insulator regions for the photonic components and bulk silicon regions for the electronic circuits, is a globally unique technology. Especially at high data rates, it enables high signal quality with low parasitic interference. The connection of the RF circuits for the radar antennas, including the frequency multiplier, to the optical transceiver can be implemented without additional wire or flip-chip bonding. Furthermore, chips can be optically and electrically tested at the wafer level, enabling a high yield in the subsequent module design. This technology enables extremely compact form factors and thus has significant relevance for the application of optical technologies based on silicon photonics in the automotive industry.

[0039] The hurdle to the productive use of optical fibers lies in the lack of scalability of currently available technologies. This scalability to large volumes is made possible by the technology for highly integrated manufacturing of electronic photonic integrated circuits. The result is a significant reduction in assembly costs and a more efficient cost structure. The development of data center solutions has resulted in comprehensive libraries of electronic and photonic components for data transmission at high bandwidths, which will be utilized in the project.

[0040] For example, the sensor system, especially for environment detection, can be - In particular, an optical device for generating an optical carrier signal, a transmitting device which has a plurality of transmitting units, wherein - In particular, the transmitting device is designed to transmit electrical transmission signals based on the optical carrier signal, comprising: - In particular, a first transmission path of the transmission device, which is designed to provide a first electrical transmission signal, which is based on the optical carrier signal, to a first transmission unit of the plurality of transmission units, which is arranged on the first transmission path, - In particular, at least one second transmission path of the transmission device, which is different from the first transmission path and is designed to generate a second electrical transmission signal based on the optical carrier signal and to provide it to a second transmission unit of the plurality of transmission units, which is arranged on the second transmission path, wherein - In particular, the transmitting device is designed to generate the second electrical transmission signal in such a way that the second electrical transmission signal has a second frequency which is different from a first frequency of the first electrical transmission signal, and - In particular, the transmitting device is designed to transmit the first electrical transmission signal with the first transmitting unit and the second electrical transmission signal with the second transmitting unit simultaneously in one transmission process.

[0041] A further aspect of the invention relates to a vehicle with a sensor system according to the preceding aspect or an advantageous further development.

[0042] For example, the vehicle may be manually operated, partially autonomous, or fully autonomous. In other words, the vehicle may be a highly automated vehicle.

[0043] In particular, the vehicle may be a motor vehicle, such as a passenger car or a truck.

[0044] For example, the sensor system can be provided with a real antenna array, which in turn has several antenna elements, such as the transmitting and receiving antennas, which are distributed on the vehicle at a distance from one another. For example, these can be arranged in the area of ​​a B-pillar of the vehicle. This allows for the most efficient detection of the vehicle's surroundings. The distributed arrangement of the individual antenna elements on the vehicle, in particular, enables 360-degree detection of the surroundings.

[0045] For example, the antenna elements of the antenna array can be configured in a sparse array configuration. In particular, the antenna elements of the antenna array can be arranged on the vehicle in a sparsely populated or weakly populated configuration.

[0046] Embodiments of individual aspects of the invention are to be considered advantageous embodiments of other aspects. In particular, the respective embodiments of individual aspects can be considered advantageous embodiments of all other aspects. This also applies in reverse.

[0047] Advantageous embodiments of the method(s) are to be regarded as advantageous embodiments of the sensor system and the vehicle. The sensor system and the vehicle have specific features that enable implementation of the method or an advantageous embodiment thereof.

[0048] 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.

[0049] The invention also includes further developments of the sensor system according to the invention and the vehicle according to the invention that have features already described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the sensor system according to the invention and the vehicle according to the invention are not described again here.

[0050] The invention also includes combinations of the features of the described embodiments.

[0051] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 a schematic representation of a vehicle with a sensor system which has antenna elements of an antenna array arranged distributed on the vehicle; Fig. 2 a schematic representation of a block diagram of the sensor system from Fig. 1; Fig. 3 a schematic representation of the vehicle from Fig. 1, where a real antenna array and a virtual antenna array for environment detection are shown; Fig. 4 shows an exemplary representation of the vehicle during a movement, whereby a simultaneous transmission of frequency-shifted signals takes place at respective measuring positions in order to generate a grid model with regard to the space to be reconstructed; Fig. 5 shows a schematic representation of the mutually frequency-shifted electrical transmission signals of the transmission process; Fig. 6 shows starting from the Fig. 5 a further representation of the electrical transmission signals, where the signals overlap in modulation ranges; Fig. 7 shows a schematic representation of the transmitter device to which the plurality of transmitting antennas may belong; Fig. 8 shows a schematic representation of the receiving device, which may, for example, have several receiving antennas; Fig. 9. shows an exemplary representation of the virtual antenna array, which may have a plurality of virtual receiving antennas generated by a computer; Fig. 10 shows a schematic representation of partial spectra of a distance spectrum of a virtual receiving antenna; Fig. 11 shows a schematic representation of the grid model for the environmental reconstruction, where information is transferred to individual areas of the grid model based on the partial spectra; Fig. 12 shows starting from the Fig. 11 a detailed view of how the individual partial spectra are projected into the grid model; Fig. 13 shows schematically how the respective partial spectra are filtered with respect to the grating model in order to compensate for the respective phase positions with respect to the grating model; and Fig. 14 shows an exemplary process for environmental reconstruction based on a virtual antenna array.

[0052] 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.

[0053] In the figures, functionally identical elements are provided with the same reference numerals.

[0054] The Fig. Figure 1 shows various schematic views (front view, rear view, side view) of a vehicle 1, which may be a motor vehicle. The vehicle 1 includes, for example, a sensor system 2.

[0055] The sensor system 2 can, for example, be a radar system or an environmental sensor system of the vehicle 1. For this purpose, the sensor system 2 can be communicatively networked with one or more driver assistance systems or other vehicle systems. For example, the sensor system 2 can be a radar sensor or a lidar sensor or another type of sensor, particularly for vehicles. In addition to the use of the sensor system 2 in the vehicle 1, it can also be used in systems external to the vehicle.

[0056] For example, the sensor system 2 has at least one antenna array or multiple antenna arrays. The antenna array can in turn be formed from a plurality of antenna elements, such as multiple transmitting antennas 3 and multiple receiving antennas 4. The antenna elements can be arranged at a distance from one another on the vehicle 1, particularly for 360-degree surroundings detection.

[0057] The Fig. Figure 2 shows a conceivable embodiment of the sensor system 2. The sensor system 2 can comprise at least one radar sensor device 5 and a central electronic computing device 6. For example, the radar sensor device 5 and the central electronic computing device 6 can be separate and physically distinct units. The radar sensor device 5 can, for example, comprise the at least one antenna array. Otherwise, the antenna array can function as the radar sensor device 5.

[0058] The central electronic computing device 6 is a central processing unit. For example, the central electronic computing device 6 can generate an electrical control signal with which a laser device 7 can be actuated or controlled. The laser device 7 can be a CW laser, for example. With the help of the laser device 7, an optical transmission signal or a carrier signal 8 can be generated. The optical transmission signal 8 can in particular be referred to as an optical carrier signal in the terahertz frequency range. The central electronic computing device 6 can, for example, generate the optical carrier frequency. The signal to be transmitted is modulated onto this optical carrier frequency with one eighth of a radar frequency and transmitted, for example, to the radar sensor device 5. In this way, an eightfold frequency increase can take place.Again, with the aid of the radar sensor device 5, signals in the gigahertz frequency range can be received and transmitted to the central electronic computing device 6.

[0059] For example, the central electronic computing device 6 can be coupled to an optical input 10 and an optical output 11 of the radar sensor device 5 via at least one optical fiber 9. Thus, bidirectional signal transmission can occur between the central electronic computing device 6 and the radar sensor device 5.

[0060] For example, the central electronic computing device 6 can be referred to as an electronic evaluation unit.

[0061] The central electronic computing device 6 can further comprise an optical receiving unit 12, which is configured to receive an optical output signal 13 provided by the optical output 11 of the radar sensor device 5. Thus, the central electronic computing device 6 can be coupled to the radar sensor device 5 via an optical fiber or electronic interface, such as Ethernet. In particular, multiple radar sensor devices or antenna arrays can be coupled to the central electronic computing device 6. For example, the central electronic computing device 6 can comprise a processing unit 14 or a computing unit, with which the received optical output signal can be processed. Thus, signal acquisition and subsequent data processing of the received output signal 11 can be carried out.

[0062] In particular, the central electronic computing device 6 can have or provide all necessary control signals, data processing signals, modules and interfaces.

[0063] For example, in addition to the optical input 10 and the optical output 11, the radar sensor device 5 can have at least one transmitting device 15, each of which can be a transmitting antenna of the plurality of transmitting antennas 3, and at least one receiving device 16, each of which can be a receiving antenna of the plurality of receiving antennas 4. Thus, the radar sensor device 5 has a receiving module and / or transmitting module. In particular, the transmitting device 15 and the receiving device 16 can be integrated on one and the same chip. It is also conceivable for them to be located on different semiconductor chips.

[0064] With the aid of the transmitting device 15, an electrical radar transmission signal 17, which is based on the optical transmission signal 8, can be transmitted into an environment 18 of the vehicle 1. Thus, a corresponding radar signal 17 can be transmitted depending on the optical transmission signal 8. If this signal 17 is reflected in the environment 18 by objects such as road users, roads, trees, or other objects, an electrical reception signal 19 corresponding to the electrical radar transmission signal 17 and reflected in the environment 18 can be received.

[0065] For example, the transmitting device 15 may have at least one antenna or one antenna unit or several antennas for transmitting.

[0066] For example, the transmitted radar transmission signal 17 or electrical transmission signal and the received reception signal 19 can be in the terahertz frequency range or gigahertz frequency range. Thus, with the aid of the sensor system 2, a frequency conversion of a terahertz carrier signal, in particular a transmission signal 8, into the gigahertz frequency range for transmission can be performed. Conversely, the reception of gigahertz signals can be performed with modulation onto the terahertz carrier signal. For example, the transmission device 15 can have at least one grating coupler and one photodiode for transmission. The reception device 16 can, for example, have two jitter couplers, a photodiode, and a modulator for reception.

[0067] Sensor system 2 can be modulated at 1 / 8 of the radar frequency and transmitted via optical fiber to the antenna chips or antenna elements. These undergo a special frequency multiplication by eight, allowing the radar radiation to be emitted from the antenna chips. Signal detection can optionally be performed in the reverse direction. All data can be processed at the central station.

[0068] The Fig. 3 shows a further embodiment of the sensor system 2. Here, the sensor system also has the computing device 6, which in this embodiment can have a different configuration or equipment.

[0069] The sensor system 2 specifically comprises a plurality of transmitting-receiving units, such as the transmitting and receiving antennas 3, 4, which can be arranged distributed on the vehicle 1, in particular for environmental detection.

[0070] The transceiver units or antenna elements can be used for both transmitting and receiving signals. Thus, the transceiver units are combined units for transmitting and receiving signals.

[0071] In particular, such a transmitting / receiving unit can be referred to as a transmitting and receiving module. This can be referred to or formed from an electronic-photonic co-integrated chip (so-called "EPIC chip"). The computing device 6, which can be referred to as the central processing unit, can also be formed from an electronic-photonic co-integrated chip. In particular, the computing device 6 is a physically and / or spatially separate unit from the transmitting / receiving units.

[0072] For example, the computing device 6 can have an optical unit or the laser device 7 or a laser. In particular, the optical unit can be designed as an optical source or as a CW laser. With the help of the optical unit, the optical transmission signal 8 or a carrier signal can be generated and thus provided. The optical transmission signal 8 can in particular be designed as an optical carrier signal in the terahertz frequency range. The computing device 6 can, for example, generate the optical carrier frequency. The signal to be transmitted can be modulated onto this optical carrier frequency with one-eighth of a radar frequency and transmitted, for example, to the transceiver units. In this way, frequency multiplication can take place. In turn, signals in the gigahertz frequency range can be received with the help of the transceiver units.

[0073] For example, the computing device 6 can be connected to a respective transmitting / receiving unit via a fiber optic cable 9, forming an optical transmission link. Signals, in particular optical signals, can be transmitted from the computing device 6 to the individual transmitting / receiving units via the fiber optic cable 9. In order to be able to send received signals from the transmitting / receiving units back to the computing device 6 for evaluation or signal processing, a respective transmitting / receiving unit can be optically coupled to the computing device 6 via an optical return channel 20.

[0074] The electrical transmission signal 17 can be transmitted, in particular into the environment 18, by at least one of the transmission / reception units. An electrical reception signal 19 corresponding to the electrical transmission signal 17 can also be received by the transmission / reception unit. For example, the transmission signal 17 can be reflected by an object in the environment 18 of the vehicle 1 and thus received as an electrical reception signal 19. The reception signal 19, which can be referred to as a radar signal, for example, can be transmitted or transferred to the computing device 6 for evaluation or signal processing. For this purpose, the electrical reception signal can be converted into an optical reception signal 21 by means of the transmission / reception unit. For example, this can be transmitted via the return channel 9 of the computing device 4. By means of an optical-electrical converter unit 22 orThe detector unit of the computing device 6 can convert the optical received signal 21 into an electrical signal 23. Unit 22 can be used, for example, for optical detection. For this purpose, the conversion can be performed, for example, via homodyne detection or heterodyne detection. Furthermore, unit 22 can perform a phase measurement and / or a phase length measurement.

[0075] Digitization can then again be performed via a digital interface 24. In particular, an analog-to-digital conversion can be performed here. For this purpose, the digital interface 24 can have an analog-to-digital converter. A processing unit 14 can be arranged downstream. This can be used, for example, for signal processing, particularly for a "low-level signal." For example, a Fast Fourier Transformation ("FFT") can be used for this purpose. The digitized, processed electrical signal 23 can then be made available to a CPU 25 of the computing device 6. In this case, radar information or environmental information contained in the electrical signal 23 can be evaluated or processed, respectively.Furthermore, an electrical return channel 26 can be provided, which provides feedback from at least one of the transmitting-receiving units to the computing device 6 and in particular to the digital interface 24.

[0076] In order to be able to carry out the most stable and low-noise environmental detection or detection of the sensor system 2, the optical transmission signal 8 can be adapted by means of frequency synthesis or gigahertz frequency synthesis. For this purpose, the computing device 6 can have a synthesis unit 27. For this purpose, the optical transmission signal 8 can be fed to or transmitted to the synthesis unit 27. For example, modulation can be carried out before the optical transmission signal 8 is made available to the synthesis unit 27. For this purpose, a modulator or modulation unit 28 can be provided. This can be designed, for example, as an arbitrary generator or arbitrary function generator (AWG). After the synthesis unit 27, for example, an optical control unit 29 and an optical switch or

[0077] A distributor 30 may be provided in the computing device 6 in order to make appropriately processed signals from the synthesis unit 27 available to the transmitting / receiving units via the fiber optic cable 9. Furthermore, a control unit 31 may be controlled by the evaluation unit 25, in particular to monitor or control the generation of the optical transmission signal. Furthermore, a control unit or feedback loop 32 may be provided.

[0078] Furthermore, the computing device 6 is electrically connected to the transmitting / receiving units via an electrical transmission path 33. An electrical control signal 34 for controlling or driving the transmitting / receiving units or antenna elements 4 can be transmitted via this electrical transmission path 33.

[0079] In particular, the computing device 6 serves to generate an optical carrier signal, the optical transmission signal 8, and feed it into a gigahertz frequency synthesis unit, e.g., the synthesis unit 27. The synthesized gigahertz signal can be transmitted in the optical spectral range via fiber, i.e., the fiber optic cable 9, to the transceiver units, so that, for example, a 77 gigahertz signal can be emitted or transmitted by the transceiver units. Signal detection, in turn, can be performed in the reverse direction. All data can be processed or processed in the computing device 6.

[0080] In the presentation in the Fig. 3, the optical carrier signal 8 can be referred to as an optically frequency-modulated carrier signal. This can be fed into a gigahertz frequency synthesis unit, such as synthesis unit 27, and the synthesized gigahertz signal can be forwarded in the optical spectral range to the transmitting device 15 to be imitated, for example, as a 77 GHz signal.

[0081] The Fig. Figure 4 illustrates an exemplary embodiment of the present invention. The present invention is particularly advantageous when a spatial extent of objects in the surroundings of the vehicle 1 is to be detected. In other words, the vehicle 1 is moving and, for example, is traveling along a trajectory 35.

[0082] For example, several transmitter antennas 3 and receiver antennas 4 can be arranged as a real antenna array 36 in the area of ​​the B-acid of the vehicle 1, so that an environment detection can be carried out to the side of the vehicle 1. Furthermore, the sensor system 2 can have further transmitter and receiver antennas, which in turn can be distributed on the vehicle 1, as already explained above. Here, the invention advantageously enables a reliable detection of outgoing structures in the vehicle's environment and an estimation of the height profiles of these structures. For this purpose, an environment reconstruction, in particular a three-dimensional environment reconstruction of the environment 18, is carried out. Here, a virtual, spatial grid model 37 is used. As in the Fig. As shown in Figure 4, this virtual grid model 37 can consist of rectangular or cuboid volume pixels.

[0083] Since the real antenna array 36 may be sparsely populated due to cost and / or space reasons, a virtual antenna array 39 is generated for the creation or generation of the grid model 37 and in particular for the environmental reconstruction.

[0084] According to the following figures, it will now be explained how the environment reconstruction can be carried out so that target information of target objects in the environment 18 can be determined on the basis of the environment reconstruction. Fig. 5 shows various frequency signal curves of electrical transmission signals 40 to 43.

[0085] For the computer-based generation of the virtual antenna array 39, a simultaneous transmission or emission of the electrical transmission signals into the environment 18 takes place. These electrical transmission signals can in turn be transmitted in time with the transmission antennas 3, in particular the transmission antennas of the real antenna array 36. As in the Fig. As shown in Figure 5 by way of example, each transmitting antenna 3 transmits the electrical transmission signals 40 to 43 in a transmission process or transmission cycle.

[0086] As in the Fig. 5, these electrical transmission signals 40 to 43 are frequency-shifted relative to one another. In particular, these electrical transmission signals 40 to 43 can be referred to as frequency-modulated signals, in particular, the electrical transmission signals 40 to 43 can pass on the optical signal 8. For example, with the Fig. Figure 5 shows that each transmission signal, i.e., signals 40 to 43, can be provided as a Sharp sequence via frequency modulation. Each transmitting antenna 3 transmits a frequency-modulated signal whose frequency differs from the transmission frequencies of the other transmitting antennas by the frequency deviation Δf.

[0087] For example, the transmitter signal with regard to the electrical transmission signals 40 to 43 can be defined as follows: sT(t)=cos(2πΦ(t))

[0088] For each transmitting antenna 3, the respective phase modulation can be mathematically described using the following equations. Φ(t)=f0t+12αt2 Φ1(t)=(f0+Δf)t+12αt2 Φ2(t)=(f0+2Δf)t+12αt2 ΦK−1(t)=(f0+(K−1)Δf)t+12αt2

[0089] The following formula can be used to determine the slope of the frequency ramp. α=ΔfTCh

[0090] The variables used previously are described below. f0 carrier frequency Δf frequency deviation α Slope of the frequency ramp T CH Modulation duration of a chirp s T (t) Transmission signal Φ K -1(t) Phase modulation of a respective transmitting antenna

[0091] In the Fig. 6 shows another possibility regarding the generation or provision of the electrical transmission signals 40 to 43. Contrary to the design in the Fig. 5, the electrical transmission signals 40 to 43 can be designed with overlapping modulation ranges. This approach enables the coverage of several overlapping frequency bands as well as the creation of larger virtual devices. The other statements regarding the Fig. 5 apply analogously here.

[0092] In the Fig. Figure 7, for example, shows how the transmitting device 15, to which the respective transmitting antennas 3 can be associated, is depicted. Any number of transmitting antennas 3 can be associated with the transmitting device 15. As shown in this illustration, the transmitting antennas 3 can be arranged on a chip or on a circuit with respect to the transmitting device 15. It is also conceivable for the transmitting antennas 3 to be arranged as separate units and thus comprise separate electrical circuits.

[0093] For example, the optical carrier signal 8 can be provided and transferred or converted into an electrical or electronic domain by means of a photodiode 44. Thus, a corresponding electrical or electronic signal is present, which in turn can be used as the output base transmission signal for modulating the individual electrical transmission signals 40 to 43. This electrical base transmission signal can optionally be amplified, for example, by means of an amplifier or electronic amplifier 45.

[0094] For example, each transmitting antenna 3 can be assigned to a respective transmission path, so that a corresponding electrical transmission signal 40 to 43 can be provided for each transmission path. For this purpose, frequency conversion units 46 to 48 can be provided in each transmission path and thus upstream of a respective transmitting antenna 3. With a respective frequency conversion unit 46 to 48 or a respective frequency converter, the optical carrier signal 8 can be converted into an electrical range and frequency-modulated accordingly for a respective transmitting antenna 3, so that each transmitting antenna 3 transmits a signal that is frequency-shifted compared to the other signals.Thus, in a respective transmission path, the frequency deviation by which the respective electrical transmission signal 40 to 43 differs at each transmission antenna 3 can be generated by means of a respective frequency conversion unit 46 to 48 depending on the optical carrier signal 8.

[0095] In particular, the mutually frequency-shifted electrical transmission signals 40 to 43 can be transmitted by all transmission antennas 3, in particular the transmission antennas of the real antenna array 36, per transmission process.

[0096] As already mentioned, the vehicle 1 can be a moving vehicle along a trajectory 35. Thus, at certain measuring positions 49 (compare Fig. 4) a transmission process can be performed in each case. Thus, a transmission process can be performed in relation to the various measuring positions 49, in which, in particular, electrical transmission signals 40 to 43 that are frequency-shifted relative to one another can be transmitted by all transmitting antennas 3.

[0097] In the Fig. 8 shows a further embodiment of the receiving device 16. Here, similar to the transmitting device 15, either all receiving elements 4 can be arranged on one chip or an integrated circuit (IC), or each receiving antenna 4 can have its own chip. In this case, a respective receiving path can be assigned to a respective receiving antenna 4. An electrical amplifier can be arranged for each receiving path and thus after a respective receiving antenna 4. For example, each incoming reception 54 to 57 can be mathematically modulated as a superposition of the time-delayed and frequency-divergent electrical transmission signals 40 to 43. The frequency-modulated original signal, in particular the optical carrier signal 8, can be used as the reference signal for the mixing process.This process can be carried out, for example, using an electronic unit 85, which can be a "mixer." For this purpose, the procedure described in . Fig. 8, the respective received signals 54 to 57 are fed to unit 58. Additionally, a carrier signal 59 can be fed to unit 58. Carrier signal 59 can be converted from optical carrier signal 8, in particular by a photodiode 60. A corresponding signal can then be transmitted downstream of unit 58, for example, to computing device 6.

[0098] For example, an I / Q modulation (not shown here) can be used to generate the beat signal considered for further processing. In other words, such a beat signal can be generated with respect to each received signal 54 to 57.

[0099] For example, such a beat signal can be defined as follows. sB(t,l)=∑k=0K−1exp(−2πj(kΔf+ατ(k,l))t−(f0+kΔf)τ(k,l))

[0100] The following definitions apply to the following variables. τ runtime delay t Index receiving antenna k Index transmitting antenna K Number of transmitting antennas s B (t, l) beat signal

[0101] In the following Fig. Figure 9 now schematically illustrates how the virtual antenna array 39 is generated or produced based on the temporally transmitted electrical transmission signals 40 to 43, for example, by means of the transmitting device 15, and the received reception signals 54 to 57, for example, by means of the receiving device 16. Above all, the virtual antenna array 39 can be formed based on the antenna manifold of the underlying physical or real transmitting / receiving antennas 3, 4. For example, the virtual antenna array 39 can have a plurality of virtual receiving antennas 61. Above all, the virtual antenna array 39 offers the advantage of having a larger number of virtual receiving antennas 61 compared to the real antenna array 36. At least the number of virtual receiving antennas 61 is many times greater than the real receiving antennas 4.

[0102] Furthermore, for example, in the Fig. 9 shows that the virtual antenna array 39 can be structured as a logical group characterized by the physical antenna positions of a receiving antenna 4 and all transmitting antennas 3. In particular, the virtual antenna array 39 can be generated based on the received electrical signals 54 to 57, the real antenna positions of the transmitting antennas 3, and the real antenna positions of the receiving antennas 4.

[0103] The underlying reception signal of a respective virtual reception antenna 61 can, for example, be determined by means of the Fig. 8 explained beat signal.

[0104] In the Fig. 10, for example, shows the corresponding generated distance spectrum 62, or range spectrum, for a virtual receiving antenna 61. This distance spectrum 62 can be written, for example, using the following formula: SB(u,l)=F{sB(t,l)}

[0105] To determine the distance spectrum 62, the electrical and, in particular, mixed reception signals 63 associated with this virtual reception antenna 62 can be taken into account. Due to the frequency conversion of the optical carrier signal 8 by a significant multiple of the chirp bandwidth, the distance spectrum 62 of the underlying reception channel or the reception antenna 61 can be separated by the imposed frequency deviation.

[0106] In other words, as in the Fig. 10, partial spectra 64 to 67 are generated or separated. In other words, the distance spectrum 62 is broken down or separated into a plurality of partial spectra 64 to 67. The partial spectra can be different spectral ranges of the distance spectrum 62. Above all, an assignment of emitted transmission signals, i.e. the transmission signals 40 to 43, to the spectral range within the spectrum of a virtual reception channel can be carried out. In other words, different electrical transmission signals 40 to 43 can be received by the respective reception antenna 4 and thus by the respectively associated virtual reception antenna 63. These, in turn, each have a different frequency deviation from one another, so that on this basis, the virtual reception antenna is broken down into partial spectra based on the respective different frequency deviations of the transmission signals 40 to 43.In other words, each of these partial spectra 64 to 67 can be selected with respect to the different frequencies or bandwidths of the transmission signals 40 to 43. For example, the transmission signal 43 can be considered or considered correspondingly for the partial spectrum 64, the transmission signal 62 for the partial spectrum 65, the transmission signal 41 for the partial spectrum 66, and the corresponding transmission signal 40 for the partial spectrum 67.

[0107] In the following Fig. Figure 11 now explains how, using a projection principle, the distance spectrum 62 of a virtual receiving antenna 61 is to be projected onto a respective volume pixel 38 within the three-dimensional grid model 37. The basis of the projection is, for example, a linear interpolation of the distance spectrum 62 as a function of the time delay that corresponds to the distance between the transmitting antenna 3, the volume pixel coordinates in the grid model 37, and the virtual receiving antenna 61.

[0108] In other words, the spectral value of a respective partial spectrum 64 to 67 is projected onto the spatial coordinate corresponding to the distance within the grid model 37. The distance spectrum 62 can therefore contain distance information. Above all, a reference can be established here in the relationship, which can be considered based on the respective measurement positions 49 during a respective transmission process. As shown in the Fig. 11, the position, in particular the relative position, of the respective transmitter antenna 3 can be considered for the assignment of a respective partial spectrum 64 to 67 to a volume pixel 38. As shown in the Fig. 4, the vehicle 1 moves along the trajectory 35 and signals can be transmitted and received at the respective measuring positions 49 in relation to the trajectory 35. Thus, as in the Fig. 4, a partial area 68 of the filter model 37 can be generated with respect to a respective measurement position 49. If the vehicle 1 now continues to travel, a partial area of ​​the spatial grid 37 can then be generated for the next measurement position 49. Thus, a reconstruction of the environment 18 can be carried out.

[0109] The following equations can be used to describe a projection of the spectral value onto a spatial coordinate corresponding to the distance within the grid model. SB(uv,l)=SB(u,l)+x1−xΔx(SB(u,l)−SB(u+1,l)) x=τ(k,l)c0 x1=uΔx τ(k,l)=‖pTx,k−pH‖2+‖pTx,l−pH‖2c0

[0110] In the Fig. Figure 12 now shows, by way of example, how the respective partial spectra 64 to 67 can be projected, instructed, or incorporated into the grid model 37. Thus, an environment modulation or an environment reconstruction can be performed.

[0111] In the Fig. Figure 13 now provides an example of how compensation for the distance-dependent fiber position of the projected partial spectrum 64 to 67 on the grid model 3 can be performed with respect to ambient modulation. For this purpose, a filtering process, i.e., filtering, can be performed. In particular, phase compensation filtering is performed here. For this purpose, the partial spectra 64 to 67 of a respective virtual antenna element 61 can be filtered.

[0112] The phase position of the projection can depend on the superposition of the phases resulting from the distance of the transmitting antennas 3 to the volume pixel coordinate and the receiving antenna 4. Consequently, the filter for compensating this phase position can take these influencing factors into account. Additionally, the individual frequency response of the corresponding transmitting antenna 3 can also be included in the analysis. After filtering, the filled projections and thus the filtered partial spectra 64 to 67 can be integrated.

[0113] For this purpose, for example, a filter function h(I) can be used to compensate for the phase position of individual partial spectra, as can be described with the following equations. Influencing factors can include the antenna positions of all transmitting antennas 3, the antenna position of the receiving antenna 4 under consideration, and the transmission frequency including the transmitting antenna. The index I refers to the currently considered virtual receiving antenna 61. h(l)=∑k=0Kexp(−2πj(f0+kΔf)τ(k,l)) τ(k,l)=‖pTx,k−pH‖2+‖pRx,l−pH‖2c0

[0114] Thus, phase image compensation filtering can be performed with this filter function.

[0115] In the Fig. 14 now explains an exemplary process with regard to the environment, for the construction by, for example, laterally installed antenna arrays in the vehicle 1.

[0116] In an optional step S10, a MIMO method can be applied. This is achieved by simultaneously transmitting frequency-converted or frequency-shifted transmission signals, such as the electrical transmission signals 40 to 43. This step S10 primarily takes place at a measurement position 49. This measurement position can, in turn, have the coordinates X, Y, and Z.

[0117] In a subsequent optional step S11, after the simultaneous imitation of the electrical transmission signals 40 to 43, the corresponding reception signals 54 to 57 can be received. Subsequently, the reception of a respective reception signal 54 to 57 can be mixed by multiplying it by the carrier signal 59.

[0118] In the optional subsequent step S12, a range spectrum or the distance spectrum 62 can be calculated for each virtual receiving antenna 61.

[0119] Subsequently, in an optional step S13, the frequency spectrum or the distance spectrum 62 can be decomposed into the partial spectra 64 to 67 depending on the frequency shifts and assignment of the corresponding transmitting antennas 3.

[0120] In a subsequent optional step S14, the projection of the partial spectra 64 to 67 of the virtual receiving antenna 61 onto the spatial grid model 37 in relation to the current measurement position 94 can then take place.

[0121] In a subsequent optional document S15, a calculation of a phase compensation filter for phase compensation of the projected partial spectrum 64 to 65 can be carried out. In this case, the receiving position of the virtual receiving antenna 61, the position of the corresponding transmitting antenna 3 and the transmitting frequency with respect to these correspondents 3 can be taken into account.

[0122] In a subsequent step S16, the compensation of the phase position within the spatial grid model 37 can be carried out for each partial spectrum 64 to 67.

[0123] In a subsequent step S17, an integration of the filtered projections of all partial spectra 64 to 67 can be carried out.

[0124] In a subsequent step S18, steps S14 to S17 are carried out for all virtual receiving antennas 61.

[0125] After the partial spectra 64 to 67 have been projected into the grid model 67 for each virtual receiving antenna 61 for this measuring position 49, the integration of the filtered projection of all virtual receiving antennas 61 takes place in an optional step S19.

[0126] Finally, in a next step S20, steps S10 to S19 can be performed for the subsequent measurement position 49 along the trajectory 35. In other words, steps S10 to S19 are performed for a respective measurement position and thus for the respective transmission process.

[0127] The following optional steps describe the invention in other words for reconstructing a detected three-dimensional environment by constructing a synthetic aperture and reconstructing the received signals by a virtual antenna array along the trajectory 35 of a vehicle 1: 1. Fully coherent 3D sensor along the vehicle B-pillar; 2. Simultaneous transmission of frequency-modulated transmission signals (transmission signals 40 to 43) of different frequencies from all transmitting antennas 3; 3. Generation of a virtual antenna array 39 by applying the MIMO method; 4. Mixing the receive signal 54 to 57 of each virtual receive channel (receive antenna 61) with the original transmit signal (carrier signal 59), which is not subject to any further frequency conversion; 5. Repeating the transmission process at equidistant intervals to construct a synthetic aperture; 6. Calculation of the range spectrum 62 for all virtual receive channels; 7. Decomposition of the range spectra depending on the frequency deviations of each transmitting antenna 3; 8. Projecting the resulting partial spectra 64 to 67 of each virtual channel onto a discrete three-dimensional volume grid 37 depending on the transmitting antenna corresponding to the partial spectrum; 9. Backprojection by filtering the association of volume pixel 38 and projected spectral value from range spectrum: a. Filter calculation based on measurement position 49 corresponding transmit antenna position, transmit frequency, 3D coordinate of the volume pixel and virtual receive antenna 61 b. Applying the filter to the phase of the corresponding volume pixel c. Storage of the filter value in a data structure equivalent to the three-dimensional space grid model for each subspectrum 10. Integration of the data structures of each sub-spectrum so that each virtual receiving channel can be assigned a filtered data structure corresponding to a measurement position and the spatial grid model at that measurement position; 11. Perform steps (7), (8) and (9) for each virtual receive channel; 12. Integration of the data structures of the back-projected three-dimensional spatial grid models of all virtual receiving channels. Each measurement position is thus assigned a spatial grid model and a data structure consisting of the sum of the filtered spectral projections onto this spatial grid model. 13. Repeat steps (5) to (11) for each new measuring position; 14. Integration of the magnitudes at the same spatial grid coordinates over all measurement positions.

[0128] In other words, the present invention can be used to construct a synthetic apparatus and reconstruct the detected environment 18. For this purpose, the vehicle 1 can generate a virtual antenna array within a measurement cycle and detect the environment 80 laterally to the vehicle's direction at equidistant intervals. In other words, a detection process and subsequent signal processing process take place for a respective measurement position 49. A three-dimensional grid model, such as grid model 37, of the environment 18 serves as the basis for the spatial projection of the distance spectrum of received signals and as the basis for the reconstruction of a three-dimensional amplitude map for capturing spatially extended structures. Thus, with the help of the filled or information-enhanced grid model 37, an improved detection of the environment, in particular of the spatially extended structures therein, such as target objects, can be achieved.

[0129] In particular, the transmitting antennas 3 and the receiving antennas 4 can be arranged as miniaturized, photonically cointegrated radar chips in a coherently distributed, thinned array 36 along the vehicle's B-pillar. By simultaneously transmitting frequency-modulated signals with different frequency bands, the virtual antenna array 39 can then be generated for a respective transmission cycle using the MIMO method. Subsequently, measurements can be performed at spatially equidistant intervals to determine the measurement positions 49, construct a synthetic aperture, and reconstruct the environment 18 into a three-dimensional environment map such as the grid model 37. List of reference symbols 1 vehicle 2 Sensor system 3 antenna array 4 antenna elements 5 Radar sensor device 6 central electronic computing device 7 optical device 8 optical carrier signal 9 Fiber optic 10 optical input 11 optical output 12 Receiving unit 13 Output signal 14 Processing unit 15 Transmitter 16 Reception device 17 electrical transmission signal 18 Surroundings 19 electrical reception signal 20 return channel 21 optical reception signal 22 optical-electrical converter unit 23 electrical signal 24 digital interface 25 CPU 26 electrical return channel 27 Synthesis unit 28 Modulator 29 optical control unit 30 optical distributors 31 Control unit 32 a feedback loop 33 electrical transmission line 34 electrical control signal 35 Trajectory 36 virtual antenna array 37 virtual spatial grid model 38 volume pixels 39 virtual antenna array 40 to 43 electrical transmission signals 44 photodiode 45 amplifiers 46 to 48 frequency conversion unit 49 measuring positions 50 to 53 amplifiers 54 to 57 electrical reception signals 58 electronic unit 49 59 carrier signal 60 photodiodes 61 virtual receiving antenna 63 Distance spectrum 63 beat signal 64 to 67 sub-spectra S10 to S20 steps QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 228916 A1

[0004] DE 10 2022 202028 A

[0005] US 10, 686, 523 B1

[0006]

Claims

[1] Method for determining at least one item of target information of a target object of a sensor system (2) which has a plurality of transmitting antennas (3) and a plurality of receiving antennas (4), wherein - in one transmission process, several electrical transmission signals (40 to 43) with different frequencies are transmitted simultaneously from the several transmission antennas (3) into an environment (18), - electrical reception signals (54 to 57) based on the transmitted electrical transmission signals (40 to 43) are received by the plurality of receiving antennas, - on the basis of the received electrical reception signals (54 to 57), antenna positions of the plurality of transmitting antennas (3) and antenna positions of the plurality of receiving antennas (4), a virtual antenna array (39) having a plurality of virtual receiving antennas (61) is generated, - an environmental reconstruction of the environment (18) is carried out on the basis of the virtual antenna array (39), and - at least one target information is determined on the basis of the environmental reconstruction. [2] Method according to claim 1, wherein a respective received electrical reception signal (54 to 57) which is assigned to a respective virtual reception antenna (61) of the virtual antenna array (39) is mixed with a carrier signal (59) on which the plurality of mutually frequency-shifted electrical transmission signals (40 to 43) are based. [3] Method according to claim 2, wherein a distance spectrum (62) is determined for each virtual receiving antenna (61) on the basis of the received signal (54 to 57) associated with the respective receiving antenna (61) and mixed with the carrier signal. [4] Method according to claim 3, wherein a respective distance spectrum (62) of a respective virtual receiving antenna (61) is broken down into partial spectra (64 to 67) depending on a transmitted electrical transmission signal (40 to 43) corresponding to the received signal (54 to 57) and on the transmitting antenna (3) transmitting this electrical transmission signal (40 to 43). [5] Method according to claim 4, wherein the partial spectra (64 to 67) of a respective virtual receiving antenna (61) are projected onto a virtual, spatial grid model (37) relating to the environment reconstruction, with which the environment (18) can be modulated three-dimensionally, depending on the transmitting antenna (3) corresponding to a respective partial spectrum of the partial spectra (64 to 67). [6] Method according to claim 5, wherein the virtual spatial grid model (37) is divided into a plurality of volume pixels (38), wherein a respective partial spectrum of the partial spectra (64 to 67) of a respective virtual receiving antenna (61) is assigned to a volume pixel of the plurality of volume pixels (38) on the basis of a relation between the corresponding transmitting antenna (3) and the virtual spatial grid model (37). [7] Method according to claim 5 or 6, wherein for a respective partial spectrum (64 to 67) a phase compensation filtering is carried out to compensate for a phase position of the respective partial spectrum in the virtual, spatial grid model (37), wherein the phase compensation filtering of a respective partial spectrum (64 to 67) is carried out on the basis of the transmitting antenna (3) corresponding to the respective partial spectrum (64 to 67), the virtual receiving antenna (61) of the respective partial spectrum (64 to 67) and a frequency of the electrical transmission signal (40 to 43) transmitted by the transmitting antenna (3) corresponding to the respective partial spectrum (64 to 67). [8] Method according to claim 7, wherein the individual partial spectra (64 to 67) of a respective receiving antenna (61) in which the phase compensation filtering was carried out are integrated. [9] Sensor system (2) with a plurality of transmitting antennas (3), a plurality of receiving antennas (4) and an electronic computing device (6), wherein the sensor system (2) is designed to carry out a method according to one of the preceding claims. [10] Vehicle (1) with a sensor system (2) according to claim 9.

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