Central unit for a photonic radar system, photonic radar system, vehicle and method for manufacturing a central unit

Abstract

The invention relates to a central unit (1) for a photonic radar system (40), comprising an optical transmitter unit (2) configured to generate an optical transmission signal (10) and to provide it at at least one optical output (7) for at least one radar sensor device (41), an optical receiver unit (3) configured to receive an optical output signal (11) from the radar sensor device (41), an electrical radar signal generation unit (4) configured to generate an electrically modulated radar signal (12) and to provide it to the optical transmitter unit (2), an electrical evaluation unit (5) configured to evaluate the received optical output signal (11) and to determine radar information (25) derived therefrom, and a communication interface (6) configured to provide the radar information (25), wherein the electrical radar signal generation unit (4),The electrical evaluation unit (5) and the communication interface (6) are implemented at least in groups as an integrated circuit (30), and wherein the optical transmitting unit (2) and the optical receiving unit (3) are implemented as a photonically integrated circuit (31) or an electronically photonically integrated circuit (32). Furthermore, the invention relates to a photonic radar system (40), a vehicle (50), and a method for manufacturing the central unit (1).

Description

[0001] The invention relates to a central unit for a photonic radar system, a photonic radar system, a vehicle and a method for manufacturing a central unit.

[0002] For automated driving, the safest possible environmental perception is essential. This involves capturing the environment using sensors such as radar, lidar, and / or cameras. A comprehensive 360° 3D environmental perception is particularly important, enabling the detection of all static and dynamic objects. Lidar, in particular, can measure precise distances and be used for classification. However, these sensors are expensive and complex to design. 360° 3D environmental perception is especially challenging, as it requires either numerous small individual sensors, typically using many individual light sources and detector elements, or the installation of large sensors (e.g., Velodyne VLC 32). Furthermore, lidar systems are susceptible to weather conditions such as rain, fog, or direct sunlight.

[0003] Radar sensors have been established in the automotive sector for years, delivering reliable and fail-safe data in all weather conditions. Even poor visibility due to rain, fog, snow, dust, and darkness hardly affects their accuracy. However, their resolution has been limited; radar systems currently in series production have a resolution of approximately 2°. To meet the requirements for Levels 4 and 5 of automated driving with safe driving functions, radar sensors must provide high-resolution, three-dimensional images in the range of 0.1° and below, with high insensitivity to environmental interference. This cannot be achieved with conventional radar technology, as the resolution of such systems is too low.

[0004] WO 2022 / 228916 A1 describes a radar sensor device comprising a transmit path and a receive path, an optical input configured to receive an optical transmission signal; an optical output configured to provide an optical output signal; an antenna configured to transmit an electrical signal and receive an electrical input signal; and a digital interface unit configured to switch between the transmit path and the receive path. The radar sensor device is configured as a system-on-chip, and the transmit path, the receive path, the optical input, the optical output, the antenna, and the digital interface unit are integrated on the system-on-chip. Furthermore, a radar system, a motor vehicle, a method for operating a radar sensor device, and a method for manufacturing a radar sensor device are also described.

[0005] DE 10 2022 202 023 A1 describes a radar sensor device for a vehicle, comprising an optical input for receiving a first optical transmission signal and a second optical transmission signal different from the first optical transmission signal; a transmitter for emitting an electrical radar transmission signal based on the first and / or second transmission signal; a receiver for receiving an electrical reception signal corresponding to the radar transmission signal; and a transformation device comprising at least one quantum element, wherein the transformation device is configured to couple the received signal, the first and second optical transmission signals into the quantum element, the quantum element being configured to generate an optical output signal depending on the coupled received signal, the first and second optical transmission signals.Furthermore, a radar system, a vehicle, and a procedure are described.

[0006] The invention is based on the objective of improving a photonic radar system.

[0007] The invention achieves the problem by a central unit for a photonic radar system with the features of claim 1, a photonic radar system with the features of claim 8, and a method for manufacturing a central unit with the features of claim 11. Advantageous embodiments of the invention are set forth in the dependent claims.

[0008] In particular, a central unit for a photonic radar system is provided, comprising an optical transmitter unit configured to generate an optical transmission signal and provide it to at least one optical output for at least one radar sensor device of the radar system, an optical receiver unit configured to receive an optical output signal from the at least one radar sensor device via at least one optical input, an electrical radar signal generation unit configured to generate an electrically modulated radar signal and provide it to the optical transmitter unit, an electrical evaluation unit configured to evaluate the received optical output signal and determine radar information derived therefrom, and a communication interface configured to provide the derived radar information.wherein the electrical radar signal generation unit, the electrical evaluation unit and the communication interface are implemented at least in groups as an integrated circuit, and wherein the optical transmitting unit and the optical receiving unit are implemented as a photonically integrated circuit or an electronically photonically integrated circuit.

[0009] Furthermore, in particular a photonic radar system is created, comprising a central unit according to one of the described embodiments, at least one radar sensor device, and at least one optical waveguide associated with the at least one radar sensor device, wherein the central unit and the at least one radar sensor device are connected by means of the at least one optical waveguide.

[0010] Furthermore, in particular a method for manufacturing a central unit according to one of the described embodiments is provided, wherein the electrical radar signal generation unit, the electrical evaluation unit and the communication interface are manufactured at least in groups as an integrated circuit, and wherein the optical transmitting unit and the optical receiving unit are manufactured as a photonically integrated circuit or an electronically photonically integrated circuit.

[0011] The central processing unit (CPU), the photonic radar system, and the method enable a more compact design of the CPU and, consequently, the photonic radar system. In particular, installation space can be saved. Furthermore, manufacturing costs for the CPU can be reduced, as different designs and chip types are no longer required. Manufacturing can also be improved in terms of efficiency, especially through simplified automation. This is achieved by implementing electronic components, such as the electrical radar signal generation unit, the electrical evaluation unit, and the communication interface, at least in groups as integrated circuits. This is further achieved by implementing optical or photonic components, such as the optical transmitter and the optical receiver, as photonically integrated circuits or electronically photonically integrated circuits.

[0012] In particular, it may be provided that all electronic components relating to the functions of the central unit are or will be combined into a single integrated circuit.

[0013] In particular, it may be provided that all optical or photonic components relating to the functions of the central processing unit are or will be combined into a single photonically integrated circuit or electronically photonically integrated circuit.

[0014] For example, the optical transmission signal is an optical carrier signal in the THz frequency range. For example, the optical output signal can be described as, or comprise or represent, a radar echo signal.

[0015] For example, the central processing unit, particularly in the configuration described below as a single-chip system, can be implemented as a hybrid BI-CMOS (SIGE) or CMOS (SIN) circuit. This combines conventional transistors and waveguide structures and / or electro-optical modulators within the silicon. The single-chip system also includes a package that encloses the chip. The manufacturing process accordingly also includes packaging of the integrated circuit or chip.

[0016] For example, silicon photonics technology can be used for the cointegration of photonic and electronic components, particularly in the single-chip system configuration described below. This enables the monolithic integration of photonic components, high-frequency electronics, and digital electronics together on a single integrated circuit or chip. Such a system offers the advantage that GHz signals can be transmitted using an optical carrier signal in the THz frequency range.

[0017] The communication interface is primarily used for communication with a vehicle, especially with the vehicle's control system and / or driver assistance systems. The communication interface can, for example, be an interface for connecting to a CAN bus, a FlexRay bus, or another suitable communication bus.

[0018] It may be provided that an additional electrical communication interface is included, via which electrical configuration and / or control signals can be transmitted between the central unit and the at least one radar sensor device. However, it may also be provided that the configuration and / or control signals are transmitted via the at least one optical fiber. Frequency division multiplexing and / or time division multiplexing methods known per se may be used for this purpose.

[0019] A radar sensor device can, for example, be designed as in the aforementioned WO 2022 / 228916 A1.

[0020] The central processing unit can, for example, track an FMCW signal and perform all signal processing and evaluation. The radar sensor(s) can be used for transmitting and receiving.

[0021] In particular, the central processing unit (CPU) can generate an optical carrier frequency in the terahertz frequency range. The signal to be transmitted, especially the optical transmission signal, is modulated onto this carrier frequency, for example, with one-eighth of the radar system's frequency, and sent to the radar sensor device via optical phase, amplitude, or frequency modulation. There, the signal is amplified eightfold, enabling the radar radiation to be emitted by the radar sensor device's antenna. Signal detection occurs via the reverse process. All data is processed, in particular, on or by the CPU.

[0022] The central processing unit (CPU) is coupled to the optical input and output of the radar sensor device via one or more optical fibers (e.g., fiber optic cables). Consequently, the optical transmission signal generated by the CPU is coupled into the optical fiber and transmitted to the optical input of the radar sensor device via optical signal transmission. Thus, the carrier signal or radar driver signal is transmitted via optical transmission paths. The optical fiber can be a fiber optic cable. The CPU is also coupled to the optical output via an optical fiber. As a result, the radar sensor device, particularly a modulation unit of the radar sensor device, can couple the optical output signal into the optical fiber and transmit it to the CPU for processing the received radar signals.

[0023] In one embodiment, the electrical radar signal generation unit, the electrical evaluation unit, the communication interface, the optical transmitter unit, and the optical receiver unit are designed as an electronically-photonically integrated circuit. Such integration of both the electrical and photonic components allows the central unit to be even more compact and further improves manufacturing. Multiple chips with electronically-photonically integrated circuits can also be provided, which can be combined in a single package, for example, using special assembly methods. However, a single chip is particularly well-suited.

[0024] In one embodiment of the method, it is accordingly provided that the electrical radar signal generation unit, the electrical evaluation unit, the communication interface, the optical transmitting unit and the optical receiving unit are manufactured as an electronically-photonically integrated circuit.

[0025] In a further developed embodiment, the electronically photonically integrated circuit is designed as a single-chip system. This allows for full integration, enabling a very compact central processing unit. It also eliminates an assembly step required with multiple chips, thus simplifying manufacturing.

[0026] In a further developed embodiment of the method, it is accordingly provided that the central unit is manufactured as a single-chip system.

[0027] In one embodiment, the electrical radar signal generation unit comprises a clock and a modulation unit, wherein the clock is configured to generate and provide an electrical clock signal, and wherein the modulation unit is configured to generate the electrically modulated radar signal. This allows an electrically modulated radar signal to be provided, which is then used to modulate an optical carrier signal in order to generate and provide the optical transmission signal.

[0028] In one embodiment, the electrical evaluation unit comprises an analog-to-digital converter and a high-performance computing unit. The high-performance computing unit is configured to evaluate the optical output signal digitized by the analog-to-digital converter and to determine the radar information from it. This provides sufficiently fast signal processing, which is particularly necessary with increased radar system resolution due to the associated increase in data volume. The high-performance computing unit can, for example, include at least one digital signal processor (DSP), at least one graphics processing unit (GPU), at least one FPGA, and / or at least one application-specific integrated circuit (ASIC), or something comparable. The specific design of the high-performance computing unit is determined in particular by the signal processing steps to be performed.

[0029] In one embodiment, the optical transmitting unit comprises at least one laser and at least one electro-optical modulator, wherein the at least one electro-optical modulator is configured to modulate light generated by the at least one laser using the electrically modulated radar signal and to generate the optical transmission signal from this.

[0030] In one embodiment, the optical receiving unit comprises at least one photodiode configured to convert and provide the received optical output signal from the at least one radar sensor device into an electrical output signal. This provides an electrical output signal that can be evaluated by the evaluation unit.

[0031] Furthermore, a vehicle is created, comprising at least one photonic radar system according to one of the described embodiments. The vehicle is, in particular, a motor vehicle. However, the vehicle can also be any other land, rail, water, air, or space vehicle.

[0032] In one embodiment of the vehicle, the photonic radar system comprises a plurality of radar sensor devices, the radar sensor devices being distributed over at least a portion of the vehicle's surface. In particular, the radar sensor devices are arranged on the surface in such a way as to enable the highest possible resolution of environmental sensing, at least for relevant areas of the environment.

[0033] The invention is explained in more detail below with reference to preferred embodiments and the figures. These show: Fig. 1 a schematic representation of embodiments of the central unit for a photonic radar system; Fig. 2 a schematic representation of another embodiment of the central unit for a photonic radar system; Fig. 3 a schematic representation of an embodiment of the photonic radar system; Fig. 4 a schematic representation of one embodiment of the vehicle.

[0034] The Fig. Figure 1 shows a schematic representation of embodiments of the central unit 1 for a photonic radar system 40. The central unit 1 comprises an optical transmitter 2, an optical receiver 3, an electrical radar signal generation unit 4, an electrical evaluation unit 5 and a communication interface 6.

[0035] The optical transmitting unit 2 is designed to generate an optical transmission signal 10 and to provide it at at least one optical output 7 for at least one radar sensor device 41 of the radar system 40.

[0036] The optical receiving unit 3 is configured to receive an optical output signal 11 from the at least one radar sensor device 41 via at least one optical input 8.

[0037] The electrical radar signal generation unit 4 is designed to generate an electrically modulated radar signal 12 and to provide it to the optical transmitting unit 2.

[0038] The electrical evaluation unit 5 is designed to evaluate the received optical output signal 11 and to determine radar information 25 derived from it.

[0039] Communication interface 6 is configured to provide the derived radar information 25. Communication interface 6 is, for example, an interface for a CAN bus or a FlexRay bus.

[0040] The electrical radar signal generation unit 4, the electrical evaluation unit 5, and the communication interface 6 are implemented, at least in groups, as an integrated circuit 30. The optical transmitter unit 2 and the optical receiver unit 3 are implemented as a photonically integrated circuit 31 or an electronically-photonically integrated circuit 32.

[0041] For the sake of clarity, only one optical transmitter 2 and one optical receiver 3 are shown. However, it is specifically intended that the central unit 1 has one optical transmitter 2 and one optical receiver 3 for each radar sensor device 41. It is also possible for components to be shared. For example, it may be possible to first generate a single modulated optical signal to create the optical transmission signal 10, which is then split into several optical transmission signals 10 by means of a 1:N switch or 1:N divider, and these are then supplied to the respective radar sensor devices 41.

[0042] The central unit 1 may also include a control unit 9, which performs monitoring and control functions. For example, this control unit 9 can control the sequence of radar measurements, monitor components of the radar system 40 for possible faults, initiate countermeasures, and / or perform maintenance and / or calibration work. The control unit 9 is also part of the integrated circuit 30. The control unit 9 is electrically connected, in particular, to the electrical radar signal generation unit 4 and the electrical evaluation unit 5.

[0043] It may also be provided that an electrical communication interface (not shown) is provided, via which electrical configuration and / or control signals 13 can be transmitted between the central unit 1 and the at least one radar sensor device 41. The communication interface can, for example, be provided by the control unit 9. However, it may also be provided that configuration and / or control signals 13 are also transmitted via the at least one optical fiber, whereby frequency-division multiplexing and / or time-division multiplexing methods known per se may be used.

[0044] It is specifically provided that the electrical radar signal generation unit 4 comprises a clock 14 and a modulation unit 15. The clock 14 is configured to generate and provide an electrical clock signal 16. The clock signal 16 is supplied, in particular, to the modulation unit 15 and the evaluation unit 5. The clock signal 16 ensures, in particular, temporal synchronization within the central unit 1 or the radar system 40. The modulation unit 15 is configured to generate the electrically modulated radar signal 12. This is done, for example, by generating a ramp. The modulation unit 15 is controlled, for example, by the control unit 9.

[0045] In particular, it is provided that the electrical evaluation unit 5 has an analog-to-digital converter 17 and a high-performance computing unit 18, wherein the high-performance computing unit 18 is configured to evaluate the optical output signal 11 digitized by means of the analog-to-digital converter 17 (or the digitized electrical output signal 22, see below) and to determine the radar information 25 from it.

[0046] It is specifically provided that the optical transmitting unit 2 comprises at least one laser 19 and at least one electro-optical modulator 20. The at least one electro-optical modulator 20 is configured to modulate light generated by the at least one laser 19 using the electrically modulated radar signal 12 and to generate the optical transmission signal 10 from this.

[0047] It is specifically provided that the optical receiving unit 3 has at least one photodiode 21, which is configured to convert and provide the received optical output signal 11 of the at least one radar sensor device 41 into an electrical output signal 22. The electrical output signal 22 can be further processed by means of additional components 23, such as an amplifier (e.g., a transimpedance amplifier) ​​and / or a filter, and is then supplied to the evaluation unit 5, in particular the analog-to-digital converter 17. Furthermore, it may be provided that IQ demodulation takes place.

[0048] The Fig. Figure 2 shows a schematic representation of another embodiment of the central unit 1 for a radar system 40. The central unit 1 is basically the same as the one in the Fig. The embodiment shown in Figure 1 is configured as follows. However, in this embodiment, the electrical radar signal generation unit 4, the electrical evaluation unit 5, the communication interface 6, the optical transmitter unit 2, and the optical receiver unit 3 are designed as an electronically photonically integrated circuit 32. The control unit 9 is also, in particular, part of the electronically photonically integrated circuit 32. Specifically, the electronically photonically integrated circuit 32 is designed as a single-chip system 33. In particular, all electronic and photonic components are then integrated.

[0049] The Fig. Figure 3 shows a schematic representation of the radar system 40. The radar system 40 is, for example, arranged in a vehicle 50. The radar system 40 comprises a central unit 1 and at least one radar sensor device 41. The at least one radar sensor device 41 can, for example, be designed like the radar sensor device described in the aforementioned WO 2022 / 228916 A1. The central unit 1 and the radar sensor devices 41 are connected to each other by means of optical fibers 42 for both a forward and a return channel. An additional electrical connection (not shown) can also be provided, for example, to transmit electrical configuration and / or control signals. The radar information 25 can, for example, be provided to a vehicle control unit 51 and / or an assistance system 52 of the vehicle 50.Based on the radar information 40, the vehicle control system 51 and / or the assistance system 52 can, for example, perform object recognition in the environment and / or plan a trajectory for a semi-automated or automated drive of the vehicle 50.

[0050] The Fig. Figure 4 shows a schematic representation to illustrate an embodiment of the radar system 40. The radar system 40 has a plurality of radar sensor devices 41, wherein the radar sensor devices 41 are arranged distributed at least over a part of a surface of the vehicle 50 (for the sake of clarity, not all of the radar sensor devices 41 shown are marked with their own reference numeral).

[0051] The central unit 1 can be manufactured in particular by means of the method described in this disclosure, wherein the electrical radar signal generation unit 4, the electrical evaluation unit 5 and the communication interface 6 are manufactured at least in groups as an integrated circuit 30, and wherein the optical transmitter unit 2 and the optical receiver unit 3 are manufactured as a photonically integrated circuit 31 or an electronically photonically integrated circuit 32. The control device 9 can also be manufactured as part of the integrated circuit 30.

[0052] It can be provided that the electrical radar signal generation unit 4, the electrical evaluation unit 5, the communication interface 6, the optical transmitter unit 2, and the optical receiver unit 3 are manufactured as an electronically photonically integrated circuit 32. The control unit 9 can also be manufactured as part of the electronically photonically integrated circuit 32.

[0053] It may further be envisaged that the central processing unit 1 is manufactured as a single-chip system 33. All electronic and photonic components are then manufactured and integrated monolithically. Reference symbol list 1 Central processing unit 2 optical transmitter units 3 optical receiving units 4 electric radar signal generation units 5 electrical evaluation unit 6 Communication interface 7 optical output 8 optical inputs 9 Control unit 10 optical transmission signal 11 optical output signal 12 electrically modulated radar signal 13 Configuration and / or control signals 14 clock generators 15 modulation units 16 clock signal 17 Analog-to-Digital Converters 18 High-performance computing equipment 19 lasers 20 electro-optical modulator 21 Photodiode 22 electrical output signal 23 additional components 25 Radar information 30 integrated circuit 31 photonically integrated circuit 32 electronically-photonically integrated circuits 33 Single-chip system 40 radar systems 41 Radar sensor device 42 optical fibers 50 vehicles 51 Vehicle control 52 Assistance systems QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] WO 2022 / 228916 A1 [0004, 0019, 0049] DE 10 2022 202 023 A1

[0005]

Claims

[1] Central unit (1) for a photonic radar system (40), comprising: an optical transmitting unit (2) which is configured to generate an optical transmission signal (10) and to provide it at at least one optical output (7) for at least one radar sensor device (41) of the radar system (40), an optical receiving unit (3) which is configured to receive an optical output signal (11) from the at least one radar sensor device (41) via at least one optical input (8), and an electrical radar signal generation unit (4) which is configured to generate an electrically modulated radar signal (12) and to provide it to the optical transmitting unit (2), an electrical evaluation unit (5) which is configured to evaluate the received optical output signal (11) and to determine radar information (25) derived therefrom, and a communication interface (6) which is set up to provide the derived radar information (25), wherein the electrical radar signal generation unit (4), the electrical evaluation unit (5) and the communication interface (6) are implemented at least in groups as an integrated circuit (30), and wherein the optical transmitting unit (2) and the optical receiving unit (3) are designed as a photonically integrated circuit (31) or an electronically photonically integrated circuit (32). [2] Central processing unit (1) according to claim 1, characterized by , that the electrical radar signal generation unit (4), the electrical evaluation unit (5), the communication interface (6), the optical transmitting unit (2) and the optical receiving unit (3) are designed as an electronically photonically integrated circuit (32). [3] Central processing unit according to claim 2, characterized by, that the electronically photonically integrated circuit (32) is designed as a single-chip system (33). [4] Central processing unit (1) according to any of the preceding claims, characterized by , that the electrical radar signal generation unit (4) comprises a clock generator (14) and a modulation unit (15), wherein the clock generator (14) is configured to generate and provide an electrical clock signal (16), and wherein the modulation unit (15) is configured to generate the electrically modulated radar signal (12). [5] Central processing unit (1) according to any of the preceding claims, characterized by , that the electrical evaluation unit (5) comprises an analog-to-digital converter (17) and a high-performance computing unit (18), wherein the high-performance computing unit (18) is configured to evaluate the optical output signal (11) digitized by means of the analog-to-digital converter (17) and to determine the radar information (25) from it. [6] Central processing unit (1) according to any of the preceding claims, characterized by , that the optical transmitting unit (2) comprises at least one laser (19) and at least one electro-optical modulator (20), wherein the at least one electro-optical modulator (20) is configured to modulate light generated by the at least one laser (19) using the electrically modulated radar signal (12) and to generate the optical transmission signal (10) from this. [7] Central processing unit (1) according to any of the preceding claims, characterized by , that the optical receiving unit (3) has at least one photodiode (21) which is configured to convert and provide the received optical output signal (11) of the at least one radar sensor device (41) into an electrical output signal (22). [8] Photonic radar system (40), comprising: a central processing unit (1) according to any one of claims 1 to 7, at least one radar sensor device (41), and at least one of the optical waveguides (42) associated with at least one radar sensor device (41), wherein the central unit (1) and the at least one radar sensor device (41) are connected by means of the at least one optical waveguide (42). [9] Vehicle (50) comprising at least one photonic radar system (40) according to claim 8. [10] Vehicle (50) according to claim 9, characterized by , that the photonic radar system (40) comprises a plurality of radar sensor devices (41), wherein the radar sensor devices (41) are arranged distributed over at least a part of a surface of the vehicle (50). [11] Method for manufacturing a central unit (1) according to any one of claims 1 to 7, wherein the electrical radar signal generation unit (4), the electrical evaluation unit (5) and the communication interface (6) are manufactured at least in groups as an integrated circuit (30), and wherein the optical transmitting unit (2) and the optical receiving unit (3) are manufactured as a photonically integrated circuit (31) or an electronically photonically integrated circuit (32). [12] Method according to claim 11, characterized by , that the electrical radar signal generation unit (4), the electrical evaluation unit (5), the communication interface (6), the optical transmitting unit (2) and the optical receiving unit (3) are manufactured as an electronically photonically integrated circuit (32). [13] Method according to claim 11 or 12, characterized by , that the central processing unit (1) is manufactured as a single-chip system (33).

Images