Method for determining target information, sensor system and vehicle

Abstract

The invention relates to a method for determining at least one piece of target information of a target object of a sensor system (2) having a plurality of transmitting antennas (3) and a plurality of receiving antennas (4), in which a plurality of transmitted signals (40 to 43), which are frequency-shifted relative to one another, are simultaneously transmitted by the plurality of transmitting antennas (3) into an environment (18) during a transmission process, receiving electrical receive signals (54 to 57) based on the transmitted electrical transmit signals (40 to 43) by the plurality of receive antennas (4), generating a virtual antenna array (39) having a plurality of virtual receive antennas (61) based on the received electrical receive signals (54 to 57), the antenna positions of the plurality of transmit antennas (3) and the antenna positions of the plurality of receive antennas (4), -performing an environment reconstruction of the environment (18) on the basis of the virtual antenna array (39), and-determining at least one piece of target information on the basis of the environment reconstruction. The invention also relates to a sensor system (2) and a vehicle (1).

Description

Technical Field

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

[0002] The invention further relates to a sensor system having a plurality of transmitting antennas, a plurality of receiving antennas and an electronic computing device.

[0003] The invention also relates to a vehicle having a corresponding sensor system. Background Art

[0004] For example, patent document WO 2022 / 228916 A1 discloses a radar sensor device designed as a single-chip system. The sensor device's transmit path, receive path, transmit device's optical input, optical output, antenna, and digital interface unit are arranged on the single-chip system.

[0005] Furthermore, patent document DE 10 2022 202028 A discloses a radar sensor device for a vehicle. The device comprises a transmitting device for transmitting a radar outgoing signal and a receiving device for receiving a received signal. The radar sensor device comprises at least one antenna structure having two metallic structural elements arranged opposite each other and spaced apart from each other, both of which constitute at least one antenna structure for generating an electrical radar outgoing signal from the metallic structural elements and modulating a received electrical received signal.

[0006] Furthermore, patent document US Pat. No. 10,686,523 B1 discloses a photonic integrated circuit having optical and electrical components for performing optical and electrical signal processing. Summary of the Invention

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

[0008] This object is achieved by a method, a sensor system, and a vehicle according to the independent claims. Advantageous developments are given in the dependent claims.

[0009] One aspect of the invention relates to a method for determining at least one target information item of a target object of a sensor system having a plurality of transmitting antennas and a plurality of receiving antennas, wherein

[0010] - in particular, during transmission, a plurality of transmission signals which are frequency-shifted relative to one another are simultaneously emitted into the environment by a plurality of transmission antennas,

[0011] - receiving an electrical receive signal based on the transmitted electrical send signal, in particular by a plurality of receive antennas,

[0012] - generating a virtual antenna array with a plurality of virtual receive antennas and a plurality of virtual receive antennas, in particular based on the received electrical receive signal, the antenna positions of the plurality of transmit antennas and the antenna positions of the plurality of receive antennas,

[0013] - performing an environmental reconstruction of the environment based on, inter alia, a virtual antenna array, and

[0014] At least one object information item is determined, in particular based on the environment reconstruction.

[0015] The proposed method allows for more efficient and, in particular, more comprehensive use of sensor systems, as target information about target objects in the sensor system's environment can be better, and in particular, more accurately, detected. A virtual antenna array can be generated by simultaneously transmitting or sending multiple, frequency-shifted electrical transmission signals into the environment for each transmission request. In other words, for each transmission operation, the sensor system transmits the electrical transmission signals or transmission signals via multiple or a predetermined number of transmitting antennas, i.e., transmitting elements. These electrical transmission signals have different frequencies relative to one another, resulting in frequency shifts relative to one another. By transmitting or sending the frequency-shifted electrical transmission signals simultaneously or at the same time, an improved and, in particular, more efficient, virtual antenna array can be generated. The creation of a virtual antenna array is particularly advantageous for signal processing and, therefore, for environmental monitoring.

[0016] Based on the transmitted and received signals, a plurality of virtual antenna elements or virtual antenna arrays can be constructed, so that, for example, the resolution capability of the sensor system can be increased as a result.

[0017] Electrically transmitted signals emitted in the environment of the transmitting system may be reflected or re-emitted accordingly, so that at least some electrical receive signals corresponding to the electrical transmitted signals may be received by the plurality of receive antennas or at least some of the plurality of receive antennas.

[0018] For the generation or production of the virtual antenna array, in particular on the system side, the received electrical signals, the corresponding real antenna positions of a plurality of, in particular real transmitting antennas, and the real antenna positions of a plurality of, in particular real receiving antennas can be taken into account.

[0019] The primary advantage of a virtual antenna array is that it can have more transmitting antennas and more receiving antennas than a real antenna array of a sensor system. Consequently, the number of virtual transmitting antennas and receiving antennas is greater, in particular, several times greater than the number of real transmitting antennas and receiving antennas. This makes it simpler and more cost-effective to use and manufacture a real sensor system, thereby obtaining more comprehensive information about target objects, in particular about the environment, and, for example, expanding its information content with target information about potential target objects. This allows, in particular, a more finely divided virtual antenna array to perform an environmental reconstruction of the environment. To this end, in addition to a single transmitted operation, multiple consecutive transmitted operations and the corresponding transmitted and received signals can also be considered. This allows, primarily when the sensor system is used in the automotive sector, to detect the spatial dimensions of target objects in the environment, such as in the vehicle environment. Environmental reconstruction, i.e., virtual three-dimensional modeling of the environment based on the virtual antenna array, allows for reliable detection of extended structures, such as target objects, in the sensor system environment. Environmental reconstruction, for example, allows for better estimation of the height profile of these structures, such as target objects.

[0020] In particular, the present method offers the advantage of increased comfort during the detection process and improved reliability of the sensor system, for example, independent of weather conditions in the sensor system's environment. The virtual antenna array and the resulting or performed environment reconstruction allow for robust environmental detection for mapping and localization. By simultaneously simulating signals with excessively long frequency offsets and the resulting virtual antenna array, detection and description can be performed within a three-dimensional environment model, such as the environment reconstruction, for mapping and localization purposes.

[0021] The proposed method can be used in particular when the sensor system is used in the automotive sector. The sensor system can be used to detect objects located near the vehicle, particularly moving objects, while the vehicle is in motion, i.e., while the vehicle is moving forward. The proposed method allows the transmitting and receiving antennas to be arranged transversely on the vehicle, for example, along the B-pillars. This allows for better environmental detection from the vehicle's transverse direction, i.e., with respect to the passenger side and the front.

[0022] For environmental reconstruction, i.e., modeling a three-dimensional virtual environment based on a real environment, simultaneous transmission of signals with frequency offsets relative to one another can be performed at defined time intervals during the vehicle's forward travel. This allows for continuous environmental monitoring based on one or more virtual antenna arrays. This allows for environmental reconstruction. Based on this environmental reconstruction or the reconstructed environment, target objects located therein can be detected better and / or more precisely, allowing target information, such as radar targets, to be expanded or designed more extensively in terms of their information content.

[0023] In one embodiment, the respective received electrical receive signals associated with the respective virtual receive antennas of the virtual antenna array are mixed with a carrier signal, based on which a plurality of frequency-shifted electrical transmit signals are derived. In other words, the electrical receive signals associated with the associated receive antennas are mixed with the original transmit signal, in particular, the electrical carrier signal. Based on the carrier signal, which can be provided by a central processing unit of the sensor system, the frequency-shifted electrical transmit signals can be generated. In other words, the mixing of the respective receive signals can be performed by multiplication with the original transmit signal, in other words, the carrier signal. This can generate a corresponding mixed signal, such as a beat signal, which is required for calculating the virtual antenna array and, in particular, for reconstructing the surroundings.

[0024] In one embodiment, a range spectrum is determined for each virtual receive antenna based on a received signal associated with the respective receive antenna and mixed with a carrier signal. This range spectrum (also referred to as a "range spectrum") allows distance information to be generated or calculated for the respective virtual receive antenna based on the mixed received signal. In particular, a corresponding range spectrum can be generated for each virtual receive antenna. Thus, corresponding distance information for the respective virtual receive antenna can be provided.

[0025] In one embodiment, the respective range spectrum of the respective virtual receiving antenna is decomposed into sub-spectra based on the emitted electrical transmitted signal corresponding to the received signal and the transmitting antenna that emitted the electrical transmitted signal. Thus, the range spectrum can be decomposed based on the corresponding real transmitting antenna. The selection is therefore based on the real transmitting antenna and, in particular, the frequency offset of the respective transmitting antenna. This is because the transmitting antennas emit electrical transmitted signals that are frequency-shifted relative to one another, so that between two transmitting antennas, the respective signal experiences or has a frequency offset compared to the others. Therefore, the spectrum of each virtual receiving antenna can be selected based on the respective real transmitting antenna that has emitted the transmitted signal corresponding to the virtual receiving antenna. This is particularly advantageous for environment reconstruction and, in particular, for three-dimensional environment modeling.

[0026] In one embodiment, the sub-spectra of the corresponding virtual receive antenna are also projected onto a virtual spatial grid model related to environmental reconstruction based on the transmit antenna corresponding to the corresponding sub-spectra from the multiple sub-spectra. The grid model can be used to model the environment in three dimensions. In other words, the sub-spectra of the corresponding virtual receive antenna can be projected onto the spatial grid model. For example, a location can be determined as a starting point relative to the corresponding transmission process. This can serve as a reference for generating the virtual spatial grid model. In other words, the grid model can be used to model or reconstruct the environment virtually or in software technology. Therefore, on the system side, a target object can be projected onto the spatial grid model based on the received receive signal and the corresponding sub-spectra. The sub-spectra can contain distance information about the target object.

[0027] According to different sub-spectra, the spatial range of the target object can be characterized or provided. This is particularly advantageous for determining target information, because more extensive information about the environment and in particular a target object or multiple target objects can be determined thereby. For example, the sub-spectra of each virtual receiving antenna can be projected onto a discrete three-dimensional volume grid, such as a virtual space grid model, according to the transmitting antenna corresponding to the corresponding sub-spectra. This can be advantageously used for environmental reconstruction of the environment. In one embodiment, it is provided that the virtual space grid model is subdivided into a plurality of volume pixels, wherein the corresponding sub-spectra of the sub-spectra of the corresponding virtual receiving antenna are allocated to the volume pixels in the plurality of volume pixels based on the relationship between the corresponding transmitting antenna and the virtual space grid model. According to the corresponding sub-spectra that can contain distance information, information can be set or filled in the corresponding volume pixel. In other words, each volume pixel of the grid model contains corresponding information, so that corresponding information about the target object can be determined thereby.

[0028] For example, the grid model can be designed as a square, which in turn allows the corresponding volume pixels to be designed as cuboids. Depending on the current grid model, and in particular depending on the environment involved, any number of volume pixels can be combined to generate the grid model. Thus, corresponding information about the detected environment, and in particular the target direction, can be provided to at least some of the volume pixels based on the virtual antenna array.

[0029] In one embodiment, phase-compensation filtering is performed on the corresponding sub-spectrum to compensate for the phase of the corresponding sub-spectrum in a virtual spatial grid model, wherein the phase-compensation filtering of the corresponding sub-spectrum is performed based on the transmitting antenna corresponding to the corresponding sub-spectrum, the virtual receiving antenna of the corresponding sub-spectrum, and the frequency of the electrical signal emitted by the transmitting antenna corresponding to the corresponding sub-spectrum. Thus, the corresponding sub-spectrum can be filtered so that corresponding phase and / or phase compensation can be performed. The transmitting antenna corresponding to the sub-spectrum, the virtual receiving antenna of the sub-spectrum, and the frequency of the electrical signal emitted by the corresponding transmitting antenna can be taken into account for the filtering. In particular, the phase-compensation filtering can compensate for the distance-induced phase of the projected or projected sub-spectrum on the grid model. This allows for better environmental modeling or reconstruction.

[0030] In one embodiment, the individual sub-spectra of the corresponding receive antennas that have undergone phase compensation filtering are integrated. Thus, the filtered projections of all sub-spectra are integrated. This allows, for example, a filtered data structure to be assigned to the corresponding receive antennas, which corresponds to, for example, a measurement location and a spatial grid model or grid model at that measurement location.

[0031] Another aspect of the present invention relates to a sensor system having multiple transmitting antennas, multiple receiving antennas, and an electronic computing device, wherein the sensor system is designed to execute or implement the method according to the aforementioned aspects or advantageous developments thereof. Thus, the method mentioned at the outset can be executed by the sensor system just described.

[0032] The sensor system can be used to reconstruct the environment of the sensor system, in particular a three-dimensional environment. 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.

[0033] In particular, the sensor system can be used to perform a frequency conversion of a terahertz carrier signal into the gigahertz frequency range after the transmission of the optical signal, and conversely receive the gigahertz signal modulated onto the terahertz carrier signal.

[0034] In particular, the proposed sensor system can be used in motor vehicles. In particular, the sensor system can be used, for example, in vehicles that are operated at least partially unmanned, and in particular, in vehicles that are operated completely unmanned. This type of automated driving requires reliable environmental perception, which can be achieved using the sensor system. Sensors such as radar, lidar, and cameras can be used to detect the surroundings or environment. This is an example of an application area for the sensor system. The sensor system can perform a complete 360-degree three-dimensional detection of the environment, thereby detecting all static and dynamic objects.

[0035] By means of the sensor system, for example, improved detection of the surroundings in the lateral area of the vehicle can be performed.

[0036] This sensor system can be used as an alternative to lidar, since lidar in particular plays an important role in redundant, robust environmental detection, since this sensor type measures distances and angles more precisely in environmental detection and can also be used for classification.

[0037] In particular, sensor systems can be used, for example, in vehicles that are at least partially unmanned, or even completely unmanned. However, reliable environmental perception is essential for achieving such automated driving. Sensors, such as radar, lidar, or cameras, are used to detect the surroundings or environment. Of particular importance is a complete 360-degree, three-dimensional image of the environment, enabling the detection of all static and dynamic objects. Sensor systems can be used for this purpose. Lidar, in particular, plays a key role in redundant and robust environmental monitoring, as this sensor type measures distances more accurately and can also be used for classification. However, these lidar sensors are costly and complex. 360-degree, three-dimensional environmental monitoring is particularly problematic, as it requires either numerous smaller individual sensors, which typically operate with multiple separate light source and detector elements, or a large lidar sensor. Furthermore, lidar sensors are susceptible to weather conditions such as rain, fog, or direct sunlight. Sensor systems can provide a remedy for this.

[0038] Radar sensors or sensor systems are also established in automotive manufacturing and provide reliable and fail-safe data in all weather conditions. Even poor visibility conditions such as rain, fog, snow, dust, or darkness have little impact on their perception reliability. However, according to the prior art, resolution has been limited. In particular, the series radars used were designed only to have an angular resolution of approximately 2 degrees. To meet the requirements of higher levels of automation in automotive manufacturing for safe driving functions, sensor systems are required to provide three-dimensional images with high angular resolution in the range of 0.1 degrees or less and high insensitivity to interference in their environment. Conventional radar technology according to the prior art cannot achieve this because the resolution of such systems is too low. The sensor system according to the present invention advantageously intervenes precisely.

[0039] The sensor system can be designed as a photonic radar sensor system, achieving increased resolution by integrating electronic and photonic components on a single semiconductor chip. FMCW signal tracking, as well as all signal processing and evaluation, takes place at the central station. Each transmitting and receiving module features an electronic-photonic co-integrated chip, known as an Epic chip. Silicon photonics technology is used for the co-integrated chip. This allows for the monolithic integration of photonic components, high-frequency electronics, and digital electronics on the chip. The technical innovation of this system lies in the transmission of gigahertz signals using an optical carrier signal in the terahertz frequency range. The central station, also known as the central electronic processing unit, generates the terahertz optical carrier frequency. The transmitted signal, at one-eighth the radar frequency, is modulated to this frequency and sent via optical fiber to the antenna chip. Frequency multiplication occurs on the chip, allowing radar radiation to be emitted from the antenna chip. Signal detection is performed in reverse. All data is processed at the central station.

[0040] However, this design is very complex to implement in chip-scale gigahertz electronics. In particular, the frequency multiplication performed on the chip after detection by the photodiodes is technically challenging and poses a significant challenge in generating gigahertz signals with a high signal-to-noise ratio and the lowest possible jitter. Consequently, gigahertz signals must be stabilized in a complex further step. Furthermore, gigahertz electronics are expensive. Furthermore, high power requirements are imposed on optical carriers, particularly lasers, as a high amount of optical power is required to generate high-precision gigahertz signals. This makes single-phase ring circuits for radar arrays with multiple distributed radar semiconductor chips difficult to implement. In particular, two photonic electronic semiconductor chips are required for the corresponding transmit and receive channels, which leads to further costs. The aforementioned problems are at least partially, and in particular completely, addressed by the sensor system according to the present invention.

[0041] In particular, the invention utilizes the fact that the radiation of a laser device, which can be designed in particular as a CW laser, is introduced into a photonic semiconductor via an optical interface. This can be the optical transmission signal or carrier signal of the CW laser.

[0042] The generation of the FMCW signal as well as the entire signal processing and evaluation are performed by a central station, such as a computing device. Each transmitting and receiving module is composed of an electronic-photonic co-integrated chip (so-called "EPIC chip"), and silicon photonics technology is used for the co-integration. This allows the photonic structural elements, high-frequency electronics and digital electronics to be integrated monolithically on the chip ("electronic-photonic co-integrated"). The technical innovation of this system lies in the signal transmission of gigahertz signals via an optical carrier signal in the terahertz frequency range. The central station generates the optical carrier frequency (terahertz). The signal to be transmitted, which has 1 / 8 of the radar frequency, is modulated to this frequency and sent to the antenna chip via optical fiber. The frequency is multiplied eight times on the chip so that the radar radiation can be emitted from the antenna chip. Signal detection is carried out in the opposite way. All data is processed at the central station.

[0043] The principle of electron-photon co-integration in a chip, which features a silicon-on-insulator region for the photonic components and a bulk silicon region for the electronic circuits, is a unique technology worldwide. This allows for high signal quality with low parasitic interference, particularly at high data rates. High-frequency circuits (including frequency multipliers) for radar antennas can be connected to the optical transceiver without the need for additional wires or flip-chip bonding. Furthermore, the chip can be optically and electrically tested at the wafer level, enabling high yields in further module designs. This technology enables extremely compact form factors, which are highly relevant for the application of optical technologies based on silicon photonics in the automotive industry.

[0044] The barrier to productive use of optical fiber lies in the lack of scalability of the technology currently available. This scalability to large volumes is enabled by highly integrated manufacturing techniques for electronic and photonic integrated circuits. The result is a significant reduction in the cost of building the technology and a more efficient cost structure. Data center solutions are developed using a broad library of electronic and photonic components for high-bandwidth data transmission, which are used in this design.

[0045] For example, a sensor system, particularly for environmental detection, may include

[0046] - an optical device, in particular for generating an optical carrier signal, a transmitting device having a plurality of transmitting units, wherein

[0047] In particular, the transmitting device is designed to transmit an electrical outgoing signal based on the optical carrier signal, and has:

[0048] a first transmission path, in particular a transmission device, which is designed to provide a first electrical transmission signal based on an optical carrier signal to a first transmission unit of a plurality of transmission units arranged on the first transmission path,

[0049] - at least one second transmission path of the transmission device, in particular different from the first transmission path, which is designed to generate a second electrical transmission signal based on the optical carrier signal and to supply it to a second transmission unit of the plurality of transmission units arranged on the second transmission path, wherein

[0050] In particular, the transmitting device is designed to generate a second electrical output signal such that the second electrical output signal has a second frequency that is different from the first frequency of the first electrical output signal, and

[0051] In particular, the transmitting device is designed to simultaneously transmit a first electrical transmit signal via the first transmitting unit and a second electrical transmit signal via the second transmitting unit during a transmission process.

[0052] Another aspect of the invention relates to a vehicle having a sensor system according to the aforementioned aspect or an advantageous development thereof.

[0053] For example, the vehicle can be a manually operated vehicle, a partially unmanned vehicle, or a fully unmanned vehicle. In other words, the vehicle can be a highly automated vehicle.

[0054] In particular, the vehicle may be a motor vehicle, such as a bus or a truck.

[0055] For example, the sensor system can include a true antenna array, which in turn includes multiple antenna elements, such as transmitting and receiving antennas, distributed and spaced apart on the vehicle. For example, they can be located in the B-pillar area of the vehicle. This allows for the most efficient possible detection of the vehicle's surroundings. The distributed arrangement of the individual antenna elements on the vehicle allows for 360-degree environmental detection, in particular.

[0056] For example, the antenna elements of the antenna array may be configured in a “sparse array” configuration. In particular, the antenna elements of the antenna array may be arranged on the vehicle in a sparse or lightly spaced configuration.

[0057] Embodiments of individual aspects of the present invention may be considered advantageous embodiments of other aspects. In particular, corresponding embodiments of individual aspects may be considered advantageous embodiments of all other aspects. And vice versa.

[0058] Advantageous embodiments of the method are considered to be advantageous embodiments of the sensor system and the vehicle. To this end, the sensor system and the vehicle have relevant features that enable the method or its advantageous embodiments to be carried out.

[0059] For application cases or application scenarios that may occur in the method and are not explicitly described here, provision may be made for outputting an error message and / or a request for user feedback and / or setting standard settings and / or a predetermined initial state according to the method.

[0060] The present invention also includes further developments of the sensor system according to the present invention and the vehicle according to the present invention, which have the same features as those already described in conjunction with the further developments of the method according to the present invention. Therefore, the corresponding further developments of the sensor system according to the present invention and the vehicle according to the present invention will not be described in detail.

[0061] The invention even comprises combinations of features of the described embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The following describes an embodiment of the present invention.

[0063] Figure 1 A schematic diagram shows a vehicle having a sensor system with antenna elements of an antenna array distributed over the vehicle;

[0064] Figure 2 Show Figure 1 Schematic diagram of the sensor system;

[0065] Figure 3 Show Figure 1 Schematic diagram of a vehicle, wherein a real antenna array for environment detection and a virtual antenna array relative thereto are shown;

[0066] Figure 4 An exemplary view shows a vehicle traveling in forward motion, wherein frequency-shifted signals are simultaneously transmitted to the corresponding measurement positions in order to thereby generate a grid model of the space to be reconstructed;

[0067] Figure 5 A schematic diagram of electrical transmitted signals that are frequency-shifted relative to each other illustrating the transmission process;

[0068] Figure 6 Shown from Figure 5 Another view of the initial electrically emitted signal, wherein here the signals overlap in the modulation region;

[0069] Figure 7 A schematic diagram illustrating a transmitting device that may include multiple transmitting antennas;

[0070] Figure 8 A schematic diagram showing a receiving device, which may have, for example, multiple receiving antennas;

[0071] Figure 9An exemplary diagram illustrating a virtual antenna array that may have multiple virtual receive antennas generated based on a computer;

[0072] Figure 10 A schematic diagram showing a sub-spectrum of a range spectrum of a virtual receiving antenna;

[0073] Figure 11 A schematic diagram of a grid model for environmental reconstruction is shown, wherein information is transferred to individual regions of the grid model based on subspectra;

[0074] Figure 12 Shown from Figure 11 A detailed view of the beginning, showing how a single subspectrum is projected onto the mesh model;

[0075] Figure 13 schematically illustrating how the respective sub-spectra are filtered in terms of the grid model to compensate for the respective phases relative to the grid model; and

[0076] Figure 14 An exemplary process for virtual antenna array-based environment reconstruction is shown. DETAILED DESCRIPTION

[0077] The embodiments described below are preferred embodiments of the present invention. In these embodiments, the components described are each individual, independently discussed features of the present invention, which also independently improve the present invention and thus also constitute components of the present invention individually or in combinations other than those shown. Furthermore, the embodiments described can also be supplemented by other already described features of the present invention.

[0078] Functionally identical elements are provided with the same reference numerals in each case in the figures.

[0079] Figure 1 Various schematic views (front view, rear view, side view) of a vehicle 1 , which may be a motor vehicle, are shown. The vehicle 1 comprises, for example, a sensor system 2 .

[0080] Sensor system 2 can be, for example, a radar system or an environmental sensor system of vehicle 1. To this end, sensor system 2 can be networked and communicated with one or more driver assistance systems or other vehicle systems. For example, sensor system 2 can be a radar sensor, a lidar sensor, or another type of sensor, particularly for use in a vehicle. In addition to being used in vehicle 1, sensor system 2 can also be used in systems external to the vehicle.

[0081] For example, sensor system 2 has at least one antenna array or multiple antenna arrays. The antenna array can in turn be composed of multiple antenna elements, for example, multiple transmitting antennas 3 and multiple receiving antennas 4. The antenna elements can be arranged spaced apart and distributed on vehicle 1, particularly for 360-degree environmental detection.

[0082] Figure 2 A possible embodiment of a sensor system 2 is shown. Sensor system 2 may include at least one radar sensor device 5 and a central electronic computing device 6. For example, radar sensor device 5 and central electronic computing device 6 may be separate and physically separate units. Radar sensor device 5 may, for example, include at least one antenna array. Alternatively, an antenna array may serve as radar sensor device 5.

[0083] The central electronic computing device 6 is a central unit. For example, the central electronic computing device 6 can generate an electrical control signal that can be used to activate or control a laser device 7. The laser device 7 can be, for example, a CW laser. Laser device 7 can be used to generate an optical transmission signal or carrier signal 8. The optical transmission signal 8 can be specifically referred to as an optical carrier signal in the terahertz frequency range. The central electronic computing device 6 can, for example, generate an optical carrier frequency. The signal to be transmitted, which has an eighth of the radar frequency, is modulated onto this optical carrier frequency and transmitted, for example, to the radar sensor device 5. This increases the frequency eightfold. Signals in the gigahertz frequency range can also be received by the radar sensor device 5 and transmitted to the central electronic computing device 6.

[0084] For example, central electronic computer 6 can be coupled to light input 10 and light output 11 of radar sensor device 5 via at least one glass fiber 9. Bidirectional signal transmission is thus possible between central electronic computer 6 and radar sensor device 5.

[0085] For example, the central electronic computing device 6 may be designated as an electronic evaluation unit.

[0086] Central electronic computing device 6 may also include a light receiving unit 12, which is configured to receive optical output signal 13 provided via optical output 11 of radar sensor device 5. Central electronic computing device 6 can thus be coupled to radar sensor device 5 via optical fibers or an electronic interface, such as Ethernet. In particular, multiple radar sensor devices or antenna arrays can be coupled to central electronic computing device 6. For example, central electronic computing device 6 may include a processing unit 14 or a computing unit, which can process the received optical output signal. Signal detection and subsequent data processing of received output signal 11 can thus be performed.

[0087] In particular, the central electronic computing device 6 can have or provide all necessary control signals, data processing signals, modules and interfaces.

[0088] For example, in addition to optical input 10 and optical output 11, radar sensor device 5 may also include at least one transmitting device 15 and at least one receiving device 16. The at least one transmitting device 15 may be one of the plurality of transmitting antennas 3, and the at least one receiving device 16 may be one of the plurality of receiving antennas 4. Thus, radar sensor device 5 includes a receiving module and / or a transmitting module. In particular, transmitting device 15 and receiving device 16 may be integrated on the same chip. It is also conceivable that they may be located on different semiconductor chips.

[0089] By means of transmitting device 15, an electrical radar transmission signal 17 based on optical transmission signal 8 can be transmitted into an environment 18 of vehicle 1. Thus, a corresponding radar signal 17 can be emitted based on optical transmission signal 8. If this signal 17 is then reflected by objects in environment 18, such as traffic participants, roads, trees, or other objects, an electrical reception signal 19 corresponding to electrical radar transmission signal 17 and reflected in environment 18 can be received.

[0090] For example, the transmitting device 15 for transmitting may have at least one antenna or antenna unit or a plurality of antennas.

[0091] 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 the gigahertz frequency range. Therefore, the terahertz carrier signal, in particular the transmission signal 8, can be frequency-converted to the kilohertz frequency range for transmission using the sensor system 2. Conversely, the gigahertz signal can be received by modulation onto the terahertz carrier signal. For example, the transmitting device 15 can have at least one grating coupler and a photodiode for transmission. The receiving device 16 can have, for example, two jitter couplers, a photodiode, and a modulator for reception.

[0092] The sensor system 2 can modulate the signal at 1 / 8 the radar frequency and transmit it via optical fiber to the antenna chip or antenna element. Frequency octupling is typically performed on the chip, allowing radar radiation to be emitted from the antenna chip. Signal detection can optionally be performed in reverse. All data can be processed at a central location.

[0093] Figure 3 A further embodiment of a sensor system 2 is shown. Here, the sensor system also has a computing device 6 which can have a different configuration or equipment in this embodiment.

[0094] The sensor system 2 has, in particular, a plurality of transmitting and receiving units, such as transmitting and receiving antennas, which can be distributed, for example, on the vehicle 1 , in particular for detecting the surroundings.

[0095] The transmitting-receiving unit or antenna element can be used to send signals, and can also be used to transmit and / or receive signals. The transmitting-receiving unit is therefore a combined unit for transmitting and receiving signals.

[0096] In particular, such a transmit-receive unit may be referred to as a transmit and receive module. This may be referred to as an electronic-photonic co-integrated chip (a so-called "EPIC chip") or may be formed thereof. The computing device 6 , which may be referred to as the central unit, may also be formed by the EPIC chip. In particular, the computing device 6 is a unit physically and / or spatially separated from the transmit-receive unit.

[0097] For example, the computing device 6 can include an optical unit or laser device 7 or laser. In particular, the optical unit can be designed as a light source or CW laser. The optical unit can be used to generate and thus provide an optical transmission signal 8 or carrier signal. The optical transmission signal 8 can 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, which has one-eighth the radar frequency, can be modulated onto this optical carrier frequency and transmitted, for example, to the transceiver unit. This allows for frequency multiplication. The transceiver unit can also receive signals in the gigahertz frequency range.

[0098] For example, the computing device 6 can be connected to the corresponding transceiver units via a glass fiber 9 as an optical transmission path. Signals, in particular optical signals, can be transmitted from the computing device 6 to the individual transceiver units via the glass fiber 9. In order to be able to transmit the signals received by the transceiver units back to the computing device 6 for evaluation or signal processing, the corresponding transceiver units can be optically coupled to the computing device 6 via an optical return channel 20.

[0099] An electrical transmit signal 17 can be transmitted, in particular, into an environment 18 via at least one transmit-receive unit. Similarly, an electrical receive signal 19 corresponding to the electrical transmit signal 17 can also be received by the transmit-receive unit. For example, the transmit signal 17 can be reflected by objects in the environment 18 of the vehicle 1 and thus received as the electrical receive signal 19. The receive signal 19, which can be referred to as a radar signal, can be sent or transmitted to the computing device 6 for evaluation or signal processing. To this end, the transmit-receive unit can convert the electrical receive signal into an optical receive signal 21. This can be transmitted, for example, via the return channel 9 of the computing device 4. The optical receive signal 21 can then be converted back into an electrical signal 23 by an optoelectronic converter unit 22 or detector unit of the computing device 6. This unit 22 can, for example, be used for optical detection. For this purpose, the conversion can be performed, for example, by homodyne or heterodyne detection. Furthermore, this unit 22 can perform phase and / or phase length measurements.

[0100] Subsequently, digitization can be performed again via the 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. The processing unit 14 can then be arranged. This can be used, for example, for signal processing, in particular in the case of "low-level signals". For this purpose, a fast Fourier transform ("FFT") can be used, for example. The digitized electrical signal 23 can then be supplied to the CPU 25 of the computing device 6. In particular, the radar information or environmental information contained in the electrical signal 23 can be evaluated or processed here. In addition, an electrical return channel 26 can be provided, which provides feedback from at least one of the transmitting and receiving units to the computing device 6, and in particular to the digital interface 24.

[0101] In order to enable the sensor system 2 to perform environmental detection or detection as stable and low-noise as possible, the optical transmission signal 8 can be adapted by 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 input or transmitted to the synthesis unit 27. For example, the optical transmission signal 8 can be modulated before it is provided to the synthesis unit 27. For this purpose, a modulator or modulation unit 28 can be provided. This can be configured as an arbitrary waveform generator or arbitrary function generator (AWG), for example. For example, an optical control unit 29 and an optical switch or distributor 30 can be provided in the computing device 6 after the synthesis unit 27 to provide the correspondingly processed signal of the synthesis unit 27 to the transmitting and receiving unit via the glass fiber 9. In addition, the control unit 31 can be controlled by the evaluation unit 25 so that the generation of the optical transmission signal can be monitored or controlled in particular. In addition, a control unit or feedback loop 32 can be provided.

[0102] Furthermore, the computing device 6 is electrically connected to the transmitting / receiving unit via an electrical transmission path 33. Electrical control signals 34 can be transmitted via this electrical transmission path 33 for controlling or activating the transmitting / receiving unit or the antenna element 4.

[0103] In particular, computing device 6 is used to generate an optical carrier signal, i.e., optical transmission signal 8, and feed it to a gigahertz frequency synthesis unit, such as synthesis unit 27. The synthesized gigahertz signal can be transmitted to the transmitter-receiver unit via optical fiber, i.e., glass fiber 9, within the spectral range, so that, for example, a 77 gigahertz signal can be transmitted or emitted by the transmitter-receiver unit. Signal detection can also be performed in the reverse manner. All data can be processed or manipulated in computing device 6.

[0104] exist Figure 3In the diagram, optical carrier signal 8 may be referred to as an optical frequency modulated carrier signal. This signal may be fed into a gigahertz frequency synthesis unit, such as synthesis unit 27, and the synthesized gigahertz signal may be forwarded to transmitting device 15 within the spectral range to be simulated as a 77 GHz signal, for example.

[0105] Figure 4 An exemplary embodiment of the invention is shown. The invention is particularly advantageous when the spatial extent of objects in the vehicle environment of vehicle 1 is to be detected. In other words, vehicle 1 is in motion and is traveling along trajectory 35, for example.

[0106] For example, the vehicle 1 is provided with a plurality of transmitting antennas 3 and receiving antennas 4 as a real antenna array 36 in the B-pillar area, so that the environment can be detected laterally from the vehicle 1. In addition, the sensor system 2 can have further transmitting and receiving antennas, which, as described above, can also be distributed on the vehicle 1. Advantageously, the invention enables reliable detection of structures in the vehicle environment to the end and estimation of the height profile of these structures. For this purpose, an environmental reconstruction, in particular a three-dimensional reconstruction of the environment 18, is performed. A virtual spatial grid model 37 is used here. Figure 4 As shown by way of example, the virtual mesh model 37 can be seen to be composed of rectangular or hexahedral volume pixels.

[0107] For cost reasons and / or space reasons, the real antenna array 36 may be sparsely arranged, so a virtual antenna array 39 is generated for the creation or generation of the grid model 37 and in particular for the environment reconstruction.

[0108] In the following figures, it is now explained how the environment reconstruction is performed so that target information of a target object in the environment 18 can be determined based on the environment reconstruction. Figure 5 The diagram shows various frequency signal curves of the electrical output signals 40 to 43 .

[0109] For the computer-based generation of the virtual antenna array 39, electrical emission signals are transmitted or emitted simultaneously or at the same time into the environment 18. These electrical emission signals can be emitted in time by the transmitting antennas 3, in particular the transmitting antennas of the real antenna array 36. Figure 5 As shown by way of example in FIG, each transmitting antenna 3 transmits an electrical transmission signal 40 to 43 during a transmission process or transmission cycle.

[0110] like Figure 5 As shown, these electrical signals 40 to 43 are frequency-shifted relative to one another. In particular, these electrical signals 40 to 43 can be referred to as frequency-modulated signals. In particular, the electrical signals 40 to 43 can be passed over the optical signal 8. For example, by Figure 5It is shown that each transmitted signal, ie, signals 40 to 43, can be provided as a Sharp sequence by frequency modulation. Each transmitting antenna 3 transmits a frequency-modulated signal, the frequency of which differs from the transmission frequency of the other transmitting antennas by a frequency deviation Δf.

[0111] For example, the following can be defined as transmission signals with respect to the electrical transmission signals 40 to 43:

[0112]

[0113] For a corresponding transmit antenna 3, the corresponding phase modulation can be mathematically described by the following equation.

[0114]

[0115]

[0116]

[0117]

[0118] The slope of the frequency ramp can be determined by the following formula.

[0119]

[0120] The variables used previously are described below.

[0121]

[0122] Figure 6 Another possibility for generating or providing electrical output signals 40 to 43 is shown in FIG. Figure 5 In contrast to the embodiment in FIG. 4 , the electrically transmitted signals 40 to 43 can be designed with overlapping modulation ranges. This approach allows the coverage of multiple overlapping frequency bands and the creation of a larger virtual device. Figure 5 The other descriptions of apply analogously here.

[0123] exist Figure 7 , for example, shows a transmitting device 15 and the associated corresponding transmitting antennas 3. Any number of transmitting antennas 3 can be assigned to the transmitting device 15. As shown in this diagram, the transmitting antennas 3 can be arranged on a chip or on a circuit in the transmitting device 15. It is also conceivable that the transmitting antennas 3 are arranged as independent units and thus consist of independent circuits.

[0124] For example, an optical carrier signal 8 can be provided and converted or transformed electrically or electronically by means of a photodiode 44. Thus, a corresponding electrical or electronic signal is present, which in turn can be used as a basic transmission signal for modulating the individual electrical output signals 40 to 43. This electrical basic transmission signal can be optionally amplified, for example, by an amplifier or an electronic amplifier.

[0125] For example, each transmitting antenna 3 can be associated with a corresponding transmission path, so that a corresponding electrical transmission signal 40 to 43 can be provided for each transmission path. For this purpose, a frequency conversion unit 46 to 48 can be provided in each transmission path and thus upstream of the corresponding transmitting antenna 3. The optical carrier signal converted into the electrical range can be frequency-modulated for the corresponding transmitting antenna 3 by the corresponding frequency conversion unit 46 to 48 or the corresponding frequency converter, so that each transmitting antenna 3 transmits a signal that is frequency-shifted compared to the other signals. Consequently, a frequency deviation is generated in the corresponding transmission path by the corresponding frequency conversion unit 46 to 48 based on the optical carrier signal 8, and the corresponding electrical transmission signals 40 to 43 at each transmitting antenna 3 differ by this frequency deviation.

[0126] In particular, for each transmission process, electrical transmission signals 40 to 43 can be emitted from all transmission antennas 3 , in particular the transmission antennas of the real antenna array 36 , which are frequency-shifted relative to one another.

[0127] As mentioned above, the vehicle 1 can be a vehicle moving along the trajectory 35. Therefore, the transmission process can be carried out for each of the determined measurement positions 49 (see Figure 4 ). A transmission process is thus respectively carried out relative to different measuring positions 49 , wherein in particular electrical transmission signals 40 to 43 which are frequency-shifted relative to one another can be emitted from all transmission antennas 3 .

[0128] Figure 8 Another variant design of the receiving device 16 is now shown in . Here, similar to the case of the transmitting device 15, all receiving elements 4 can be arranged on a chip or an integrated circuit (IC), or each receiving antenna 4 can have its own chip. In this case, the corresponding receiving path can be assigned to the corresponding receiving antenna. For each receiving path and therefore after the corresponding receiving antenna 4, an electrical amplifier can be arranged. For example, each input reception 54 to 57 can be mathematically modulated as a superposition of time-delayed and frequency-divergent electrical transmission signals 40 to 43. In this case, the frequency-modulated original signal, in particular the optical carrier signal 8, can be used as a reference signal for the mixing process. This process can be carried out, for example, with the aid of an electronic unit 85, which can be a "mixer". For this purpose, as Figure 8As shown in the example, the corresponding received signals 54 to 57 can be input to a unit 58. In addition, a carrier signal 59 can also be supplied to the unit 58. The carrier signal 59 can be converted from an optical carrier signal 8 by a photodiode 60, in particular. The corresponding signal can then be transmitted downstream of the unit 58, for example, to a computing device 6.

[0129] For example, an I / Q modulation (not shown here) can generate a clock signal that is taken into account for further processing. In other words, such a clock signal can be generated in each of the received signals 54 to 57.

[0130] For example, such a clock signal can be defined as follows.

[0131]

[0132] To this end, the following definitions are understood using the following variables.

[0133]

[0134] In the following Figure 9 Schematically, the diagram now illustrates how a virtual antenna array 39 is generated or produced based on, for example, electrical transmit signals 40 to 43 transmitted over time by a transmitter 15 and receive signals 54 to 57 received by a receiver 16. In particular, the virtual antenna array 39 can be designed based on the antenna manifold of the underlying physical or real transmit / receive antennas 3, 4. For example, the virtual antenna array 39 can include a plurality of virtual receive antennas 61. In particular, the virtual antenna array 39 offers the advantage of having a greater number of virtual receive antennas 61 than the real antenna array 36. The number of virtual receive antennas 61 is at least several times greater than the number of real receive antennas 4.

[0135] In addition, for example Figure 9 , the virtual antenna array 39 is structured as a logical group, characterized by the physical antenna positions of the 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.

[0136] The received signal based on the corresponding virtual receiving antenna 61 can be obtained, for example, by Figure 8 The interpreted beat signal corresponds to

[0137] exist Figure 10 In FIG. 6 , for example, the associated generated distance spectrum 62 or range spectrum, Range-Spektrum, is shown for the virtual receiving antenna 61. The distance spectrum 62 can be expressed, for example, by the following formula:

[0138]

[0139] To determine the range spectrum 62, the electrical and, in particular, mixed, received signal 63 associated with the virtual receiving antenna 62 can be considered. Due to the frequency conversion of the optical carrier signal 8 to an integer multiple of the chirp bandwidth, the range spectrum 62 of the underlying receiving channel or receiving antenna 61 can be separated by the applied frequency deviation.

[0140] In other words, Figure 10 As shown, sub-spectra 64 to 67 can be generated or separated. In other words, the range spectrum 62 is decomposed or separated into a plurality of sub-spectra 64 to 67. The sub-spectra can be different spectral ranges of the range spectrum 62. In particular, the transmitted transmission signals, namely, the transmitted signals 40 to 43, can be assigned to spectral ranges within the spectrum of the virtual receive channel. In other words, different electrical transmitted signals 40 to 43 can be received by the respective receive antennas 4, and therefore also by the respectively associated virtual receive antennas 63. These signals, in turn, have different frequency deviations relative to one another, so that, based on the different frequency deviations of the transmitted signals 40 to 43, they are decomposed into sub-spectra in the virtual receive antennas. In other words, each of these sub-spectra 64 to 67 can be selected for a different frequency or bandwidth of the transmitted signals 40 to 43. For example, the transmitted signal 43 can be considered or observed for sub-spectra 64, the transmitted signal 62 for sub-spectra 65, the transmitted signal 41 for sub-spectra 66, and the corresponding transmitted signal 40 for sub-spectra 67.

[0141] In the following Figure 11 In the following, it is now explained how the distance spectrum 62 of the virtual receiving antenna 61 is projected onto the corresponding volume pixel 38 in the three-dimensional mesh model 37 by means of the projection principle. The basis for the projection is, for example, a linear interpolation of the distance spectrum 62 according to the time delay corresponding to the distance between the transmitting antenna, the volume pixel coordinates in the mesh model 37 and the virtual receiving antenna.

[0142] In other words, the spectral values of the respective sub-spectra 64 to 67 are projected onto spatial coordinates corresponding to the distances within the grid model 37. The distance spectrum 62 can thus contain distance information. In particular, a reference can be established in this context, which can be taken into account during the respective emission process based on the respective measurement position 49. Figure 11 As shown by way of example, the position, in particular the relative position, of the corresponding transmitting antennas 3 can be taken into account for assigning the corresponding sub-spectra 64 to 67 to the volume pixel 38. Figure 4 As shown by way of example in FIG, the vehicle 1 moves along a trajectory 35 and can send corresponding reception signals for corresponding measurement positions 49 relative to the trajectory 35. Figure 4As schematically shown, a subregion 68 of the filter model 37 can be generated for the respective measurement position 49. If the vehicle 1 continues to travel, a subregion of the spatial grid 37 can be generated again for the next measurement position. Thus, a reconstruction of the environment 18 can be performed.

[0143] The projection of the spectral values onto the spatial coordinates corresponding to the distance within the grid model can be described by the following equation.

[0144]

[0145]

[0146]

[0147]

[0148] Figure 12 , it is now shown by way of example how the respective sub-spectra 64 to 67 are projected or indicated or incorporated into the grid model 37. Thus, an environment modeling or environment reconstruction can be performed.

[0149] exist Figure 13 Here, an example is now described of how the projected sub-spectra 64 to 67 are compensated for the distance-dependent fiber layers on the grid model 3 with respect to the environment model. For this purpose, a filtering process, i.e., filtering, can be performed. In particular, phase compensation filtering is performed. For this purpose, the sub-spectra 64 to 67 of the corresponding virtual antenna element 61 can be filtered.

[0150] The phase of the projection can depend on the superposition of phases resulting from the distances of the transmit antenna 3 to the volume pixel coordinates and the receive antenna 4. The filter can therefore compensate for this phase by taking these influencing factors into account. Additionally, the individual frequency columns corresponding to the transmit antenna 3 can also be taken into account. After filtering, the filled projections and thus the filtered sub-spectra 64 to 67 are integrated.

[0151] For this purpose, for example, the filter function h(l) can be used to compensate the phase of the individual subspectra, as described by the following equation. Influencing factors can be the antenna positions of all transmit antennas, the antenna position of the considered receive antenna 4, and the transmit frequency of the transmit antennas. The continuous index l here refers to the currently considered virtual receive antenna 61.

[0152]

[0153] Therefore, phase image compensation filtering can be performed by this filter function.

[0154] exist Figure 14An exemplary process in terms of an environment is now explained for a system constructed by, for example, a transversely mounted antenna array in vehicle 1 .

[0155] In optional step S10 , a MIMO method can be applied. This is done by transmitting a frequency-converted or frequency-shifted transmit signal simultaneously with the electrical transmit signals 40 to 43 . In particular, step S10 is performed at a measurement location 49 . This measurement location can in turn have coordinates X, Y, and Z.

[0156] In a subsequent optional step S11 , after simultaneous simulation of the electrical outgoing signals 40 to 43 , the corresponding received signals 54 to 57 can be received. The reception of the corresponding received signals 54 to 57 can then be mixed by multiplication with a carrier signal 59 .

[0157] In an optional subsequent step S12 , a range spectrum or distance spectrum can be calculated for each virtual receiving antenna 61 .

[0158] Subsequently, an optional step S13 may decompose the frequency spectrum or range spectrum 62 into sub-spectra 64 to 67 according to the frequency offset and the allocation of the corresponding transmit antennas 3 .

[0159] In a subsequent optional step S14 , the sub-spectra 64 to 67 of the virtual receive antenna 61 may be projected onto the spatial grid model 37 relative to the current measurement position 94 .

[0160] In a subsequent optional step S, a phase compensation filter can be calculated for phase compensation of the projected sub-spectra 64 to 65. The reception position of the virtual reception antenna 61, the position of the corresponding transmission antenna 3 and the transmission frequency relative to these counterparts 3 can be taken into account.

[0161] In a subsequent step S16 , a compensation of the phase within the spatial grid model 37 can be performed for each sub-spectrum 64 to 67 .

[0162] In a subsequent step S17 , an integration of the filtered projections of all sub-spectra 64 to 67 can be performed.

[0163] In subsequent step S18 , steps S14 to S17 are respectively executed for all virtual receiving antennas 61 .

[0164] After the sub-spectra 64 to 67 have been projected for each virtual receiving antenna 61 for the measurement position 49 into the grid model 67 , in an optional step S19 the filtered projections of all virtual receiving antennas 61 are integrated.

[0165] Finally, in the next step S20, steps S10 to S19 can now be carried out for the subsequent measurement position 49 along the trajectory 35. In other words, steps S10 to S19 are carried out for the respective measurement position and thus for the respective transmission process.

[0166] The following describes the optional steps of the invention, in other words, for reconstructing the detected three-dimensional environment by constructing a synthetic aperture along the trajectory 35 of the vehicle 1 and by reconstruction of the signals received by the virtual antenna array:

[0167] 1. 3D fully coherent sensors along the vehicle's B-pillar;

[0168] 2. Simultaneously transmitting frequency-modulated transmission signals of different frequencies from all transmitting antennas 3 (transmitting signals 40 to 43);

[0169] 3. Generate a virtual antenna array 39 by applying the MIMO method;

[0170] 4. The received signals 54 to 57 of each virtual receiving channel (receiving antenna 61) are mixed with the original transmitted signal (carrier signal 59) without further frequency conversion;

[0171] 5. Repeat the transmission process at equally spaced intervals to construct a synthetic aperture;

[0172] 6. Calculate the range spectrum 62 for all virtual receiving channels;

[0173] 7. Decompose the range spectrum based on the frequency deviation of each transmitting antenna 3;

[0174] 8. Projecting the resulting sub-spectra 64 to 67 of each virtual channel onto the discrete three-dimensional volume grid 37 according to the transmit antenna corresponding to the sub-spectra;

[0175] 9. Backprojection is performed by correlation of the filtered volume pixels 38 and the projected spectral values from the range spectrum:

[0176] a. Filter calculation based on the measurement position 49, the corresponding transmit antenna position, the transmit frequency, the 3D coordinates of the volume pixel and the virtual receive antenna 61

[0177] b. Apply the filter to the corresponding volume pixel

[0178] c. For each sub-spectrum, store the filter value in a data structure equivalent to a three-dimensional space grid model

[0179] 10. Integrate the data structure of each sub-spectrum so that each virtual receiving channel can be assigned a filtered data structure corresponding to a measurement location and a spatial grid model at the measurement location;

[0180] 11. Perform steps (7), (8), and (9) for each virtual receiving channel;

[0181] 12. A data structure of the back-projected three-dimensional spatial grid model integrating all virtual receiving channels. Each measurement location 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;

[0182] 13. Repeat steps (5) to (11) for each new measurement location;

[0183] 14. A quantity integrated over the same spatial grid coordinates at all measurement locations.

[0184] In other words, the present invention enables the construction of a synthetic aperture and the reconstruction of the detected environment 18. To this end, vehicle 1 can generate a virtual antenna array during a measurement cycle and detect the environment 80 at equidistant distances transverse to the vehicle direction. In other words, a detection process is performed at the corresponding measurement position 49, followed by a signal processing process. A three-dimensional grid model of the environment 18, such as grid model 37, serves as the basis for the spatial projection of the range spectrum of the received signal and for the reconstruction of a three-dimensional amplitude map to understand spatially extended structures. Thus, the detection of the environment, particularly spatially extended structures such as target objects, can be improved using a populated or information-enhanced grid model 37.

[0185] In particular, the transmitting antennas 3 and receiving antennas 4 can be arranged as miniaturized photonic co-integrated radar chips in a coherently distributed sparse array 36 along the vehicle's B-pillars. By simultaneously transmitting frequency-modulated signals with different frequency offsets, a virtual antenna array 39 can then be generated for the corresponding transmission period using a MIMO approach. Subsequently, measurements performed at spatially equidistant distances can be used to construct a synthetic aperture and reconstruct the environment 18 into a three-dimensional environment map, such as a mesh model 37.

[0186] Reference Signs List

[0187] 1 vehicle

[0188] 2-sensor system

[0189] 3-antenna array

[0190] 4 antenna elements

[0191] 5 radar sensor device

[0192] 6Central electronic computing equipment

[0193] 7 Optical equipment

[0194] 8 optical carrier signals

[0195] 9. Fiberglass

[0196] 10 optical input port

[0197] 11 Optical output port

[0198] 12 receiving units

[0199] 13 output signal

[0200] 14 processing units

[0201] 15 launchers

[0202] 16 receiving device

[0203] 17 Electricity sends a signal

[0204] 18 Environment

[0205] 19 Electrical receiving signal

[0206] 20 Return Channel

[0207] 21 optical receiving signal

[0208] 22 photoelectric converter units

[0209] 23 electrical signals

[0210] 24 digital interfaces

[0211] 25CPU

[0212] 26 electrical return channels

[0213] 27 synthesis units

[0214] 28 modulator

[0215] 29 Optical control unit

[0216] 30 optical splitters

[0217] 31 control unit

[0218] 32 Feedback Loop

[0219] 33 Electrical transmission path

[0220] 34 electrical control signals

[0221] 35 tracks

[0222] 36 virtual antenna arrays

[0223] 37 Virtual Space Grid Model

[0224] 38 volume pixels

[0225] 39 virtual antenna array

[0226] 40 to 43 electric signals

[0227] 44 photodiodes

[0228] 45 amplifier

[0229] 46 to 48 frequency conversion units

[0230] 49 measurement positions

[0231] 50 to 53 amplifiers

[0232] 54 to 57 electrical receiving signals

[0233] 58 Electronic Unit 49

[0234] 59 carrier signal

[0235] 60 photodiodes

[0236] 61 virtual receiving antennas

[0237] 63 Distance Spectrum

[0238] 63 beat signal

[0239] 64 to 67 sub-scores

[0240] Steps S10 to S20.

Claims

1. A method for determining at least one target information item of a target object of a sensor system (2), the sensor system having a plurality of transmitting antennas (3) and a plurality of receiving antennas (4), wherein - during the transmission process, a plurality of electrical transmission signals (40 to 43) which are frequency-shifted relative to one another are simultaneously transmitted by a plurality of transmission antennas (3) into the environment (18), - receiving, by a plurality of receiving antennas, electrical reception signals (54 to 57) based on the transmitted electrical transmission signals (40 to 43), - generating a virtual antenna array (39) having a plurality of virtual receiving antennas (61) based on the received electrical receiving signals (54 to 57), the antenna positions of the plurality of transmitting antennas (3) and the antenna positions of the plurality of receiving antennas (4), - performing an environmental reconstruction of the environment (18) based on a virtual antenna array (39), and - determining at least one target information based on the environment reconstruction.

2. The method according to claim 1, wherein The respective received electrical receive signals (54 to 57) corresponding to the respective virtual receive antennas (61) of the virtual antenna array (39) are mixed with a carrier signal (59) on which a plurality of electrical transmit signals (40 to 43) that are frequency-shifted relative to one another are based.

3. The method according to claim 2, wherein A range spectrum (62) is determined for each virtual receiving antenna (61) based on a received signal (54 to 57) associated with the corresponding receiving antenna (61) and mixed with a carrier signal.

4. The method according to claim 3, wherein A respective range spectrum (62) of a respective virtual receiving antenna (61) is decomposed into sub-spectra (64 to 67) according to an emitted electrical transmission signal (40 to 43) corresponding to a received signal (54 to 57) and a transmitting antenna (3) which emits the electrical transmission signal (40 to 43).

5. The method according to claim 4, wherein The sub-spectra (64 to 67) of the corresponding virtual receiving antenna (61) are projected onto a virtual spatial grid model (37) related to the environment reconstruction according to the transmitting antenna (3) corresponding to the corresponding sub-spectra in the plurality of sub-spectra (64 to 67), and the environment (18) can be three-dimensionally modeled through the grid model.

6. The method according to claim 5, wherein The virtual space grid model (37) is subdivided into a plurality of volume pixels (38), wherein a corresponding sub-spectrum of the sub-spectrum (64 to 67) of a corresponding virtual receiving antenna (61) is allocated to one volume pixel in the plurality of volume pixels (38) based on a relationship between a corresponding transmitting antenna (3) and the virtual space grid model (37).

7. The method according to claim 5 or 6, wherein Phase-compensation filtering is performed on the corresponding sub-spectra (64 to 67) to compensate the phase of the corresponding sub-spectra in the virtual spatial grid model (37), wherein Phase-compensation filtering of the corresponding sub-spectrum (64 to 67) is performed based on the transmit antenna (3) corresponding to the corresponding sub-spectrum (64 to 67), the virtual receive antenna (61) of the corresponding sub-spectrum (64 to 67), and the frequency of the electrical transmit signal (40 to 43) transmitted by the transmit antenna (3) corresponding to the corresponding sub-spectrum (64 to 67).

8. The method according to claim 7, wherein The respective sub-spectra (64 to 67) of the corresponding receiving antenna (61) for which phase-compensation filtering has been performed are integrated.

9. A sensor system (2) comprising 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 the method according to one of the preceding claims.

10. A vehicle (1) having a sensor system (2) according to claim 9.

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