Method for generating a frequency-modulated transmission signal for a transmission device, computer program product, computer-readable storage medium, transmission device and detection apparatus
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-07
- Publication Date
- 2026-04-08
Smart Images
Figure EP2024062662_05122024_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Method for generating a frequency-modulated transmission signal for a transmission device, computer program product, computer-readable storage medium, transmission device and detection device
[0003] The invention relates to a method for generating a frequency-modulated transmission signal for a transmission device of a detection device for transmitting the transmission signal into an environment of the detection device. Furthermore, the invention relates to a corresponding computer program product, a corresponding computer-readable storage medium, a corresponding transmission device, and a corresponding detection device.
[0004] Radar sensor devices for motor vehicles are already known from automotive engineering. In particular, such radar sensor devices are used in, for example, at least partially autonomous vehicles, but especially also in fully autonomous vehicles. However, to enable such automated driving, reliable environmental perception is essential. The environment is recorded using sensors such as radar, lidar, and cameras. A holistic 360-degree three-dimensional recording of the environment is particularly important so that all static and dynamic objects can be detected. Lidar, in particular, plays a key role in redundant, robust environmental detection, as this type of sensor can precisely measure distances in environmental detection and can also be used for classification. However, these lidar sensors are cost-intensive and complex to construct.360-degree three-dimensional environment detection is particularly problematic, as it requires either many smaller individual sensors, which typically operate with many individual light sources and detector elements, or large lidar sensors. Furthermore, lidar sensors are susceptible to weather influences such as rain, fog, or direct sunlight.
[0005] Radar sensors and radar sensor devices are also well-established in automotive engineering and deliver reliable and fail-safe data in all weather conditions. Even poor visibility conditions such as rain, fog, snow, dust, or darkness barely affect their detection reliability. However, the current state of the art has limited resolution; in particular, series-produced radars currently in use are only designed with a resolution of approximately 7 degrees. To meet the requirements for increased automation in automotive engineering with safe driving functions, radar sensor devices are designed to deliver three-dimensional images with high resolution in the range of 0.1 degrees and below, with high immunity to interference from their surroundings.This cannot be achieved with conventional radar technology according to the state of the art, as the resolution of such systems is too low.
[0006] In particular, photonic radar sensor devices are already known that achieve an increase in resolution by cointegrating electronic and photonic components into a single semiconductor point. The tracking of an FMCW signal, as well as the entire signal processing and evaluation, are performed by a central station. Each transmit and receive module has an electronic-photonic cointegrated chip, a so-called EPIC chip. Silicon photonics technology is used for the cointegration. This enables the monolithic integration of photonic components, radio-frequency electronics, and digital electronics together on a single chip. The technical innovation of such a system lies in the signal transmission of gigahertz signals using the optical carrier signal in the terahertz frequency range.A central station, which can also be referred to as a central electronic computing device, generates an optical carrier frequency in terahertz. The signal to be transmitted is modulated onto this carrier frequency at one-eighth of the radar frequency and sent to the antenna chips via optical phase shift. The frequency is then multiplied eightfold, allowing the radar radiation to be emitted by the antenna chips. Signal detection occurs in the opposite direction. All data is processed at the central station. However, such a design is very complex in the implementation of gigahertz electronics at the chip level. In particular, the frequency quadrupling that takes place on the chip after detection by a photodiode is technically challenging and represents a significant effort in terms of gigahertz signal generation with a high signal-to-noise ratio and the lowest possible jitter. The gigahertz signal must therefore be stabilized in complex further steps.Furthermore, gigahertz electronics are cost-intensive. Furthermore, high performance requirements are placed on the optical carrier, especially a laser, since high optical power is required to generate a high-precision gigahertz signal, making a single-phase loop difficult to implement for a radar array with many distributed radar semiconductor chips. In particular, two different photonic-electronic semiconductor chips are still required for each transmit and receive channel, resulting in further cost increases.
[0007] As already described, photonic radar systems or lidar systems based on frequency-modulated continuous waves (FMCW) are known from the state of the art. These systems can be designed, for example, as frequency-modulated continuous wave radar or frequency-modulated continuous wave lidar.
[0008] These systems require optical frequency-modulated continuous wave signals for operation. These are often generated using a continuous wave (CW) laser and a subsequent intensity modulator, such as a Mach Zehnder modulator, controlled by an electrical signal. Any phase jumps are translated directly into the optical signal. These jumps can lead to problems in signal processing during evaluation.
[0009] A solution to this problem can be found in current technology, for example, in optical mode-locked sources such as a Kerr resonator or mode-locked lasers (MLL - multi-line lasers). The output signal of these sources is already phase-stabilized. However, Kerr oscillators, which are particularly easy to integrate, deliver very little power. In contrast, MLLs, which were previously impossible to integrate, deliver high power, but also radiate increased thermal energy.
[0010] In particular, when using Kerr oscillators as pulse sources, both oscillators are already pumped with an optical FMCW signal. Furthermore, it is known that the pulse source is used to compensate for the nonlinearity of an existing FMCW laser signal.
[0011] A disadvantage of these known systems is that they require existing FMCW laser signals. Furthermore, the systems are difficult to stabilize thermally, as the two optical rings, for example, must be thermally coupled. Furthermore, it is known that the pulse sources are not used to stabilize the FMCW ramp, but rather for an advantageous embodiment of signal localization. Furthermore, it is known, for example, in photonic radar systems, that the optical signal must be converted into an electrical signal. This is usually done using a photodiode. However, due to the lack of double-sideband modulation, the photodiode cannot generate any temporally modified signal.WO 2022 / 157191 A1 relates to a radar sensor device for a motor vehicle with at least one central electronic computing device which is designed to generate an electrical control signal for a transmitting device, a laser device which, depending on the electrical control signal, generates an optical transmission signal for transmission to the transmitting device, with a transformer device with at least one first optical ring resonator which generates a pulse train depending on the optical transmission signal, wherein the transformer device is designed to generate an electrical transmission signal depending on the pulse train, with the transmitting device which is designed to transmit the electrical transmission signal, and with a receiving device for receiving an electrical reception signal for transmitting the electrical reception signal to the central electronic computing device.
[0012] JP 2019 039972 A describes generating a signal, such as a microwave and a millimeter wave, with suppressed phase noise, in a frequency-variable state without specifically requiring a stable optical frequency comb reference light source.
[0013] CN 114 36 19 31 A discloses a very low noise electro-optical frequency comb generating device, comprising: an optical frequency comb module for generating an optical frequency comb; the continuous laser module is used to output a stable frequency reference laser and a continuous laser for electro-optical modulation; a feedback module for locking the optical frequency comb to the reference laser and for locking the continuous laser to the optical frequency comb; the microwave frequency generating module is used to receive the optical frequency comb and convert the optical frequency comb into a microwave signal; and the electro-optical modulation module is used to receive the microwave signal to perform electro-optical modulation on the continuous laser to generate an electro-optical frequency comb.
[0014] The object of the present invention is to provide a method, a corresponding computer program product, a corresponding computer-readable storage medium, a corresponding transmitting device and a corresponding detection device by means of which a frequency-modulated continuous wave signal can advantageously be generated.
[0015] This object is achieved by a method, a corresponding computer program product, a corresponding computer-readable storage medium, a corresponding transmitting device, and a corresponding detection device according to the independent patent claims. Advantageous embodiments are specified in the subclaims.
[0016] One aspect of the invention relates to a method for generating a frequency-modulated transmission signal for a transmitting device of a detection apparatus for transmitting the transmission signal into an environment of the detection apparatus. A frequency comb is generated by means of an optical mode-locked source of the transmitting device. At least one frequency line in the generated frequency comb is filtered by means of a first optical filter device of the transmitting device. A frequency-modulated transmission signal is generated by means of a photodiode of the transmitting device as a function of the filtered frequency comb, wherein the transmission signal is generated proportional to the frequency difference from the filtered frequency line.
[0017] In particular, an optical bandpass filter is proposed that filters out at least one frequency line, in particular a finite plurality of frequency lines, from the frequency comb. The frequency-modulated transmission signal is generated based on the filtered frequency comb. The frequency-modulated transmission signal is, in particular, a frequency-modulated continuous wave (FMCW) signal.
[0018] In particular, the detection device can be designed for a so-called continuous-wave radar, especially a frequency-modulated continuous-wave radar, as well as for a frequency-modulated continuous-wave lidar. For distance measurement in particular, corresponding sawtooth or triangular functions are usually used for this purpose. In the embodiment of the continuous-wave radar, this can be a radar system that differs from a pulsed radar in that the transmitting device operates continuously for the duration of the measurement process. In particular, with the so-called continuous-wave radar, the transmitted frequency is modulated. Based on the continuous-wave radar, for example, a contactless speed measurement based on the Doppler effect or even a motion detector can be used accordingly.Continuous-wave radar devices can also be used, for example, for distance or altitude measurement, or as short-range navigation radar on ships or boats. The frequency-modulated transmission signal is thus a periodically frequency-modulated signal, which allows for a high degree of accuracy in a measurement that is essentially linear over time. Continuous-wave radar, however, is only one of several applications. The transmission device can also be used for radio-based communication, for example.
[0019] In particular, it is thus provided that the optical mode-locked source generates the frequency comb, with a finite number of frequency lines being filtered out from this frequency comb and the selection of these lines being separated. The photodiode then generates the signal to be transmitted based on the filtered signal, which is in particular proportional to the frequency difference of the selected lines.
[0020] In particular, any desired modulation, such as a frequency-modulated ramp, can be generated using an optical mode-locked source. This signal is already phase-stabilized due to its generation method.
[0021] In contrast to the state of the art, for example, no separate laser device is required to generate the frequency-modulated signal. Since only lines from a mode-locked source are required, the system also does not require thermal stabilization. Furthermore, based on the proposed method, a time-variable signal can be generated within the photodiode. Thus, for example, a photonic radar can be realized.
[0022] It should be noted in particular that the proposed detection device can be used not only in automotive engineering, but also, for example, in corresponding production facilities for monitoring a manufacturing process. In particular, in addition to the radar device, a radio device or, more generally, a communication device for wireless communication based on the generated transmission signal can also be provided.
[0023] According to an advantageous embodiment, at least one second optical filter device is provided, wherein at least one further frequency line is filtered by means of the second optical filter device. In particular, these signals can then be combined and transmitted together to the photodiode. Based on the different frequencies, the frequency-modulated transmission signal can again be reliably generated by the photodiode.
[0024] Furthermore, it has proven advantageous if at least one further frequency line is filtered by means of the first optical filter device. In particular, it is thus provided that at least two frequency lines, in particular more than two frequency lines, for example, three or more frequency lines, are filtered out by means of the one optical filter device. This makes it possible for the frequency-modulated transmission signal to be reliably generated by means of the photodiode using a single optical filter device.
[0025] A further advantageous embodiment provides for at least two frequency lines to be brought closer together by means of an optical dispersive element of the transmitting device. In particular, depending on the repetition frequency of the optically modulated source, the selected lines can be brought closer together using the optional dispersive optical element. The decomposition of light into its wavelength components is called dispersion. An element with this property is called a dispersive element. This makes it possible to generate different frequency-modulated transmission signals.
[0026] It is further advantageous if at least two frequency lines are further separated by means of an optical dispersive element of the transmitting device. In particular, depending on the repetition frequency of the optically modulated source, the selected lines can be separated from each other using the optional dispersive optical element. This makes it possible to generate different frequency-modulated transmission signals.
[0027] A further advantageous embodiment provides for the dispersive element to be arranged downstream of the optical filter device in the beam path. This allows the dispersive element to reliably spread or converge the frequency lines further based on the already filtered signal, thereby enabling improved transmission signal generation.
[0028] A further advantageous embodiment provides that the dispersive element is arranged in the beam path upstream of the optical filter device. The frequency comb is thus already compressed or expanded, for example, by the dispersive element, which allows for improved filtering. It is also advantageous if a frequency ramp is generated as the frequency-modulated transmission signal. The frequency ramp is in particular a substantially triangular transmission signal. In this case, descending or ascending frequency ramps can be generated. With the ascending frequency ramp, the frequency of the transmitted signal thus increases over time. With the descending frequency ramp, the frequency, in turn, decreases over time. The proposed method can therefore be advantageously used, for example, in a continuous-wave radar or a continuous-wave lidar.
[0029] According to an advantageous embodiment, heterodyne detection is performed in the photodiode. Heterodyne detection is a signal processing method for detecting waves of an unknown frequency by mixing them with waves of a reference frequency. In particular, this allows for reliable analysis of the corresponding signals. Alternatively, homodyne detection can also be performed. This is a method for detecting the modulation of an oscillation by mixing them with a nearly identical reference frequency. Thus, corresponding detection can be realized in different ways.
[0030] Furthermore, it has proven advantageous if the detection device is provided as a photonic radar device or as a lidar device. Alternatively or additionally, the detection device can also be used for a communication device, for example a radio device. Thus, the method / transmission device can be used highly flexibly in different situations where appropriate transmission signals are required. A radio signal can be understood here and below as electromagnetic waves whose frequencies are less than or equal to 3 THz and which propagate in space without artificial guidance. Corresponding frequency ranges for the radio signal can correspond to low-frequency waves, radio waves, or microwaves. For example, the frequency of the electromagnetic waves can be between 3 Hz and 3 THz, in particular between 100 MHz and 100 GHz.A well-known type of lidar system is a so-called laser scanner, in which a laser beam is deflected by a light deflection device, allowing different deflection angles of the laser beam to be achieved. The light deflection device can, for example, contain a rotatably mounted mirror. Alternatively, the light deflection device can have a mirror element with a tiltable and / or pivotable surface. The mirror element can, for example, be designed as a microelectromechanical system (MEMS). The emitted laser beams can be partially reflected in the environment, and the reflected portions can in turn strike the laser scanner, in particular the light deflection device, which can direct them onto a detector unit of the laser scanner. Each optical detector of the detector unit generates, in particular, an associated detector signal based on the portions detected by the respective optical detector.Based on the spatial arrangement of the respective detector, together with the current position of the light deflection device, in particular its rotational position or its tilt and / or pivot position, the direction of incidence of the detected reflected components can be determined. An evaluation unit can also, for example, perform a time-of-flight measurement to determine the radial distance of the reflecting object. Alternatively or additionally, a method can be used to determine the distance by evaluating a phase difference between emitted and detected light.
[0031] Other types of lidar systems are flash lidar systems. These are non-scanning systems that do not require such a light deflection arrangement. The laser light generated by the light source is scattered by an optical element, so that it is emitted in a single flash over a wide angle. This creates a high degree of flexibility and application possibilities for the method and the transmitting device.
[0032] The presented method is, in particular, also a computer-implemented method. Therefore, a further aspect of the invention relates to a computer program product with program code means that cause an electronic computing device, when the program code means are processed by the electronic computing device, to perform a method according to the preceding aspect.
[0033] Yet another aspect of the invention relates to a computer-readable storage medium having at least one computer program product according to the preceding aspect.
[0034] Furthermore, the invention also relates to a transmitting device for a detection device for generating a frequency-modulated transmission signal for transmitting the transmission signal to an environment of the detection device, comprising at least one optical mode-locked source, a first optical filter device, and a photodiode. The transmitting device is configured to carry out a method according to the preceding aspect. In particular, the method is carried out by means of the transmitting device.
[0035] For example, the transmitting device additionally has an electronic computing device in order to generate the frequency comb or to adjust the filter device accordingly.
[0036] A computing unit / electronic computing device can be understood, in particular, as a data processing device that contains a processing circuit. The computing unit can therefore, in particular, process data to perform computing operations. This may also include operations for performing indexed access to a data structure, for example, a look-up table (LUT).
[0037] The computing unit may, in particular, contain one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more single-chip systems (SoCs). The computing unit may also contain one or more processors, for example one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The computing unit may also include a physical or virtual network of computers or other of the aforementioned units.
[0038] In various embodiments, the computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.
[0039] A memory unit can be a volatile data memory, for example a dynamic random access memory (DRAM) or a static random access memory (SRAM), or a non-volatile data memory, for example a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory or flash EEPROM, a ferroelectric random access memory (FRAM), a magnetoresistive random access memory,MRAM (magnetoresistive random access memory) or phase-change random access memory (PCRAM).
[0040] The invention also relates to a detection device with at least one transmitting device according to the preceding aspect.
[0041] Yet another aspect of the invention relates to a motor vehicle with a detection device according to the preceding aspect. The motor vehicle can be designed, for example, as an at least partially electrically powered motor vehicle or as a fully electrically powered motor vehicle. Furthermore, the motor vehicle can be designed as an at least partially autonomous motor vehicle or as a fully autonomous motor vehicle.
[0042] For use cases or application situations that may arise during the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and / or a request to enter user feedback is issued and / or a default setting and / or a predetermined initial state is set.
[0043] The invention also includes further developments of the transmitting device according to the invention that have features already described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the transmitting device according to the invention are not described again here.
[0044] For example, the detection device can be designed for a vehicle guidance system. Therefore, one aspect also relates to an electronic vehicle guidance system with a corresponding detection device. An electronic vehicle guidance system can be understood as an electronic system that is configured to guide a vehicle fully automatically or fully autonomously, in particular without requiring intervention in the control system by a driver. The vehicle automatically performs all required functions, such as steering, braking, and / or acceleration maneuvers, the observation and detection of road traffic, and corresponding reactions. In particular, the electronic vehicle guidance system can implement a fully automatic or fully autonomous driving mode of the motor vehicle according to level 5 of the classification according to SAE J3016.An electronic vehicle guidance system can also be understood as an advanced driver assistance system (ADAS), which supports the driver in partially automated or semi-autonomous driving. In particular, the electronic vehicle guidance system can implement a partially automated or semi-autonomous driving mode according to levels 1 to 4 of the SAE J3016 classification. Here and below, "SAE J3016" refers to the corresponding standard in the April 2021 version.
[0045] The at least partially automated vehicle guidance may therefore include driving the vehicle according to a fully automated or fully autonomous driving mode of Level 5 according to SAE J3016. The at least partially automated vehicle guidance may also include driving the vehicle according to a partially automated or semi-autonomous driving mode according to Levels 1 to 4 according to SAE J3016.
[0046] Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures can be encompassed by the invention not only in the respectively specified combination, but also in other combinations. In particular, the invention can also encompass embodiments and combinations of features that do not have all the features of an originally formulated claim. Furthermore, the invention can encompass embodiments and combinations of features that go beyond the combinations of features set out in the backreferences to the claims or deviate from them.
[0047] The invention also includes combinations of the features of the described embodiments.
[0048] Exemplary embodiments of the invention are described below. Figure 1 shows a schematic plan view of an embodiment of a motor vehicle with an embodiment of a detection device with an embodiment of a transmitting device;
[0049] Fig. 2 is a schematic block diagram according to an embodiment of the transmitting device; and
[0050] Fig. 3 is yet another schematic block diagram according to an embodiment of the transmitting device.
[0051] The exemplary embodiments explained below are preferred exemplary embodiments of the invention. In the exemplary embodiments, the described components each represent individual, independently considered features of the invention, which also further develop the invention independently of one another and are thus also to be considered as components of the invention, either individually or in a combination other than that shown. Furthermore, the described exemplary embodiments can also be supplemented by further features of the invention already described.
[0052] In the figures, functionally identical elements are provided with the same reference numerals.
[0053] Fig. 1 shows a schematic plan view of an embodiment of a motor vehicle 1. The motor vehicle 1 can be designed as an at least partially electrically operated motor vehicle 1 or as a fully electrically operated motor vehicle 1. In particular, the motor vehicle 1 can also be designed as an at least partially assisted motor vehicle 1 or as a fully assisted motor vehicle 1. The motor vehicle 1 has at least one detection device 2. The detection device 2 is designed in particular to detect or capture an environment 3. In the present exemplary embodiment, an object 4 is in the environment 3.For this purpose, the detection device 2 has a transmitting device 5, a receiving device 6 and an electronic computing device 7, which can be used, for example, to evaluate a transmitted signal 8 in relation to a received signal 9, which in the present embodiment was reflected by the object 4.
[0054] The detection device 2 can preferably be designed as a radar device. Alternatively or additionally, the detection device 2 can also be designed as a lidar device. Alternatively or additionally, the presented method can also be designed essentially for radio-based communication.
[0055] Fig. 1 shows, in particular, the transmitted signal 8, which can also be referred to as a frequency-modulated transmitted signal 8. As already mentioned, the frequency-modulated transmitted signal 8 is reflected by the object 4 and received as a received signal 9 by the receiving device 6. Based, for example, on corresponding phase differences or the like, both a distance and, for example, the speed of the object 4 can be detected, based on a Doppler effect.
[0056] Fig. 2 shows a schematic block diagram according to an embodiment of the transmitting device 5. The transmitting device 5 is designed in particular to generate the frequency-modulated transmitted signal 8 and to transmit the transmitted signal 8 into the environment 3. In this case, a frequency comb 11 is generated by means of an optical mode-locked source 10. A frequency line 12 in the generated frequency comb 11 is filtered by means of a first optical filter device 13 of the transmitting device 5. The frequency-modulated transmitted signal 8 is generated by means of a photodiode 14 as a function of the filtered frequency comb 11, wherein the frequency-modulated transmitted signal 8 is proportional to the frequency difference to the filtered frequency line 12.
[0057] The presented embodiment shows in particular that a second optical filter device 16 can be provided, wherein at least one further frequency line 17 can be filtered by means of the second optical filter device 16.
[0058] Furthermore, it is shown that at least one further frequency line 12, 17 is filtered, for example by means of the first optical filter device 13 and also in the present case by means of the second optical filter device 16.
[0059] It is further shown that, in particular, adjustment of the first optical filter device 13 and / or the second optical filter device 16 can be carried out via the electronic computing device 7. In the present case, the adjustment can also be referred to as so-called tuning. The electronic computing device can, for example, also be coupled to the optical mode-locked source 10 to generate the frequency comb 11. Furthermore, Fig. 2 shows that at least two frequency lines 12, 17 can be brought closer together by means of an optical dispersive element 18 of the transmitting device 5, or at least two frequency lines 12, 17 can be pulled further apart by means of the optical dispersive element 18.
[0060] In the present embodiment, it is shown in particular that the dispersive element 18 is arranged in the beam path after the first optical filter device 13 and / or the second optical filter device 16.
[0061] Fig. 3 shows a further schematic embodiment of the transmitting device 7. In the present exemplary embodiment, the dispersive element 18 is arranged in the beam path in front of the first optical filter device 13 and / or the second optical filter device 16.
[0062] It can further be provided that a frequency ramp is generated as the frequency-modulated transmission signal 8. Furthermore, it can be provided that the photodiode 14 is designed in particular for heterodyne detection. Alternatively or additionally, the photodiode 14 can also be designed for homodyne detection.
[0063] In particular, it can be provided that the optical mode-locked source 10 generates the frequency comb 11. A finite number of frequency lines 12, 17 can be filtered out from this frequency comb 11, and the selected lines can be separated accordingly. Depending on the repetition frequency of the optical mode-locked source 10, the selected frequency lines 12, 17 can be brought closer together or spread further apart using the optional dispersive element 18. The transmitted signal 8, which is proportional to the frequency difference of the selected lines, is then generated in the photodiode 14.
[0064] In particular, the presented transmitting device 5 can be used to generate any desired modulation, for example, an FMCW ramp, using the optical mode-locked source 10. The FMCW ramp is, in particular, a frequency-modulated continuous wave (FMCW) ramp. Due to the way it is generated, this signal is phase-stabilized and can therefore be used very advantageously, especially in motor vehicles 1.
[0065] Overall, Figs. 1 to 3 show a system for generating frequency-modulated signals using the frequency comb 11. List of reference symbols
[0066] motor vehicle
[0067] Detection device
[0068] Vicinity
[0069] object
[0070] transmitting device
[0071] Receiving device electronic computing device transmitting signal
[0072] Receive signal optical mode-locked source
[0073] Frequency comb
[0074] Frequency line first optical filter device
[0075] Photodiode filtered frequency comb second optical filter device further frequency line dispersive element
Claims
Patent claims 1. Method for generating a frequency-modulated transmission signal (8) for a transmission device (5) of a detection device (2) for transmitting the frequency-modulated transmission signal (8) into an environment (3) of the detection device (2), comprising the steps: Generating a frequency comb (11) by means of an optical mode-locked source (10) of the transmitting device (5); Filtering at least one frequency line (12) in the generated frequency comb (11) by means of a first optical filter device (13) of the transmitting device (5); and Generating the frequency-modulated transmission signal (8) by means of a photodiode (14) of the transmitting device (5) depending on the filtered frequency comb (15), wherein the frequency-modulated transmission signal (8) is generated proportional to the frequency difference to the filtered frequency line (12).
2. Method according to claim 1, characterized in that at least one second optical filter device (16) is provided, wherein at least one further frequency line (17) is filtered by means of the second optical filter device (16).
3. Method according to claim 1 or 2, characterized in that at least one further frequency line (17) is filtered by means of the first optical filter device (13).
4. Method according to one of the preceding claims, characterized in that at least two frequency lines (12) are brought closer together by means of an optical dispersive element (18) of the transmitting device (5).
5. Method according to one of claims 1 to 3, characterized in that at least two frequency lines (12) are pulled further apart by means of an optical dispersive element (18) of the transmitting device (5).
6. Method according to claim 4 or 5, characterized in that the dispersive element (18) is arranged in the beam path after the first optical filter device (13).
7. Method according to claim 4 or 5, characterized in that the dispersive element (18) is arranged in the beam path in front of the first optical filter device (13).
8. Method according to one of the preceding claims, characterized in that a frequency ramp is generated as the frequency-modulated transmission signal (8).
9. Method according to one of the preceding claims, characterized in that heterodyne detection is carried out in the photodiode (14).
10. Method according to one of the preceding claims, characterized in that the detection device (2) is provided as a photonic radar device or as a lidar device.
11. Method according to one of the preceding claims, characterized in that the detection device (2) is provided for a motor vehicle (1) and / or for a production plant.
12. Computer program product with program code means which cause an electronic computing device (7) to carry out a method according to one of claims 1 to 11 when the program code means are processed by the electronic computing device (7).
13. A computer-readable storage medium comprising at least one computer program product according to claim 12.
14. A transmitting device (5) for a detection device (2) for generating a frequency-modulated transmission signal (8) for transmitting the frequency-modulated transmission signal (8) into an environment (3) of the detection device (2), comprising at least one optical mode-locked source (10), a first optical filter device (13) and a photodiode (14), wherein the transmitting device (5) is designed to carry out a method according to one of claims 1 to 11.
15. Detection device (2) with at least one transmitting device (5) according to claim 14 and with a receiving device (6).