Method for operating a radar sensor assembly, radar sensor assembly, computer program product, computer-readable storage medium

Abstract

The invention relates to a method for operating a radar sensor assembly (100), comprising measuring an environment in a measurement mode (I), wherein a voltage-controlled oscillator (110) generates a radar wave and the radar echo generated by the radar wave in the environment is detected, and precisely and deterministically measuring a control characteristic curve of the voltage-controlled oscillator (110) in a calibration mode (II), wherein the voltage-controlled oscillator (110) is actuated by a field-programmable gate array (120) both in the measurement mode (I) and in the calibration mode (II). The invention also relates to a radar sensor assembly, to a computer program product and to a computer-readable storage medium.

Description

[0001] Method for operating a radar sensor assembly, radar sensor assembly, computer program product, computer-readable storage medium

[0002] The invention relates to a method for operating a radar sensor assembly, a radar sensor assembly, a computer program product and a computer-readable storage medium.

[0003] Radar technology plays an indispensable role in the precise detection and interpretation of environmental data. Especially in combination with assistance systems, radar sensors enable reliable 360-degree detection of the vehicle's surroundings, thus significantly improving road safety. The same applies to the use of radar sensors in traffic safety technology, where they are used in stationary and mobile traffic safety systems.

[0004] A voltage-controlled oscillator is typically used to transmit a radar signal. To generate a desired radar wave, the voltage-controlled oscillator must be controlled according to a control characteristic. However, this control characteristic is subject to fluctuations and interference, which can negatively impact the radar wave quality. In particular, temperature drift and aging of the oscillator can lead to the actually emitted radar wave not corresponding to the desired radar wave.

[0005] However, measuring the control characteristic can be very time-consuming, so measurements are only performed prior to commissioning or at long intervals. This can, however, reduce the accuracy of the radar wave.

[0006] It is therefore an object of the present invention to at least partially overcome at least one of the disadvantages described above. In particular, the object of the invention is to provide a method for operating a radar sensor assembly, a radar sensor assembly, a computer program product, and a computer-readable storage medium that allow the transmission of a radar wave that corresponds as closely as possible to a specification.

[0007] The above object is achieved by a method for operating a radar sensor assembly, by a radar sensor assembly, by a computer program product, and by a computer-readable storage medium. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the radar sensor assembly according to the invention and / or in connection with the computer program product according to the invention and / or in connection with the computer-readable storage medium according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0008] According to the invention, a method for operating a radar sensor assembly is provided, comprising:

[0009] - Measuring an environment in a measuring mode, whereby a voltage-controlled oscillator generates a radar wave and the radar echo generated by the radar wave on the environment is detected,

[0010] - Measuring a control characteristic of the voltage-controlled oscillator in a calibration mode, whereby the voltage-controlled oscillator is controlled by a field programmable gate array (FPGA) in both the measurement mode and the calibration mode.

[0011] In other words, it can be provided that a radar sensor assembly is operated, whereby both a measurement of the environment and a measurement of the characteristic curve of a voltage-controlled oscillator are carried out, whereby both measurements are controlled via an FPGA.

[0012] The method can be implemented as a computer-implemented method.

[0013] The method steps can be performed at least partially simultaneously and / or sequentially, whereby the sequence of the method steps is not limited by the specified order, so that individual steps can be performed in different orders. Furthermore, individual or all steps can be performed repeatedly.

[0014] A radar sensor assembly can be understood as a group of elements that are intended to be joined together to form a functional unit. It can be provided that the components of the radar sensor assembly are arranged in a housing. Alternatively or additionally, it can also be provided that at least one component, in particular those components that are not arranged on the field programmable gate array, is / are arranged at a distance from it in the assembly. In particular, at least one radar front end or one antenna can thus be flexibly arranged to detect the environment, in particular on a vehicle and / or in a mobile or stationary traffic safety system. The radar sensor assembly can be understood as part of a radar sensor. The radar sensor can comprise further devices, in particular at least one processor, a main memory or a network interface.The processor can be designed to evaluate the measured radar echo and / or the control characteristic, in particular conditioned in an output signal. Alternatively or additionally, the output signal can be at least partially evaluated in the field-programmable gate array. The processor can further be designed to provide an input signal, in particular comprising a control signal for generating the radar echo according to the measured control characteristic of the voltage-controlled oscillator. The evaluation can include converting the radio echo signal into environmental information. The radar sensor module can include a main memory. The main memory can be understood as a central memory area designed for the intermediate storage of data and can be connected to the processor, in particular, via a fast data bus and / or a specific interface.

[0015] Detection of the environment can include object detection. Objects can be, in particular, vehicles, pedestrians, bicycles, and other obstacles in the environment, in particular the environment of a vehicle and / or a mobile or stationary traffic safety system. Furthermore, detection of the environment can also include distance measurement and / or angle measurement. In other words, the measurement of a distance and / or an angle to an object can be provided. Detection of the environment can also include a measurement of at least one speed. Furthermore, it can be provided that the detection is implemented as an all-round detection (in particular 360°) of the environment. The detection of the environment can serve as input data for a vehicle assistance system and / or for violation detection of a mobile or stationary traffic safety system.A measurement mode can be understood as a state of the radar sensor array in which a measurement of the environment is carried out by transmitting and receiving radar waves. The measurement mode can be implemented as a separate operating mode in which only the measurement of the environment is performed. Alternatively, it can be configured for the radar sensor assembly to perform other tasks even while the measurement mode is running.

[0016] It is also conceivable to omit the measurement mode, particularly at least temporarily, in a method according to the invention. The measurement of the control characteristic can, for example, be provided during the production of the radar sensor assembly, and the measurement can only be performed when the radar sensor assembly is at least being used for its intended purpose or installed.

[0017] It may be provided that the calibration mode is carried out for at least two different temperatures, in particular by recording a temperature-dependent control characteristic. It may be provided that the radar sensor assembly for this measurement is placed in a climatic chamber.

[0018] A voltage-controlled oscillator (VCO) can be understood as an electronic circuit designed to generate an oscillating voltage at an output of the voltage-controlled oscillator, the frequency of which is controlled by an external electrical voltage at an input of the voltage-controlled oscillator. The voltage-controlled oscillator can comprise an oscillating element, in particular an LC resonant circuit (coil and capacitor), varactor diodes, resonators, components with negative resistance, an active component, in particular a transistor and / or an operational amplifier, and a voltage control unit.

[0019] It can be provided that the voltage-controlled oscillator is operated in an open loop. In other words, it can be provided that the voltage-controlled oscillator is operated without feedback. By omitting feedback, components can be saved and the circuit can be simplified. Furthermore, the voltage-controlled oscillator can react more quickly. This is particularly advantageous for complex radar wave signals. It can be provided that the voltage-controlled oscillator generates the transmission frequency of the radar wave. Furthermore, it can be provided that a frequency multiplier, a mixer stage, or filter are provided to generate the desired carrier frequency. It can also be provided to amplify the output signal of the voltage-controlled oscillator, in particular by a power amplifier.It can be provided that the output signal of the voltage-controlled oscillator is modulated, in particular by a modulation unit. It can be provided that at least one amplitude modulation (AM), frequency modulation (FM), or phase modulation (PM) takes place. The voltage-controlled oscillator can be located in either an open loop (open loop) or a closed loop (closed loop or phase-locked loop). Furthermore, it can be provided that the possibly processed and / or modulated signal of the voltage-controlled oscillator is forwarded to a radar antenna. It can also be provided that the radar antenna transmits the signal into the room and / or receives reflected signals from objects in the environment.

[0020] Capturing the generated radar echo may include at least detecting or analyzing reflected radar waves bounced off objects in the surrounding area. The radar assembly may receive the radar echo with an antenna. The received echo signals may be processed to extract information about the distance, direction, speed, and other properties of the reflecting objects.

[0021] Measuring a control characteristic may include measuring the output signal generated by the voltage-controlled oscillator for a defined control signal sent to the voltage-controlled oscillator. Measuring the output signal may include at least the frequency, the amplitude, or a frequency distribution.

[0022] Conversely, measuring a control characteristic can also involve measuring the required input signal of the voltage-controlled oscillator for a known frequency of the voltage-controlled oscillator while it is in a closed control loop (closed loop or phase-locked loop). The measurement of the input signal can comprise at least one voltage value or a distribution of many voltage values. A state of the radar sensor group in which a measurement of the control characteristic of the voltage-controlled oscillator is effected can be understood as a calibration mode. The calibration mode can be implemented as a separate operating mode in which only the measurement of the control characteristic is carried out. Alternatively, it can be provided that other tasks are also performed by the radar sensor module while the calibration mode is running.It can be provided that the measured control characteristic is used to control the voltage-controlled oscillator in a subsequent measurement mode. Alternatively or in addition, an older and / or averaged control characteristic can also be used.

[0023] The voltage-controlled oscillator is controlled by the field-programmable gate array in both measurement mode and calibration mode. This can be done almost directly in measurement mode, while in calibration mode, it can be controlled indirectly via the frequency synthesizer. In other words, the voltage-controlled oscillator can receive control signals from the FPGA both when measuring the control characteristic and when measuring the environment. Furthermore, the FPGA can at least receive or evaluate the corresponding measured values, i.e., the radar echo and the control characteristic (or the output signal of the voltage-controlled oscillator depending on the input signal), in both modes.

[0024] A field programmable gate array can be understood as an integrated circuit (IC) that is designed to load a logic circuit as data and to behave according to the logic of the circuit data. The field programmable gate array can be designed as a single chip. It can be provided that all steps of the method are at least controlled or executed by the FPGA. It can also be provided that at least individual steps of the method are at least controlled or executed by a processor. In particular, the processor can be designed to at least control the FPGA or to evaluate an output signal from the FPGA, which includes at least the radar echo or the control characteristic.

[0025] Overall, the method according to the invention achieves the advantage that radar waves can be emitted that correspond as closely as possible to a specified value. Because the voltage-controlled oscillator is controlled by the FPGA in both measurement mode and calibration mode, the modes can run quickly. In particular, the calibration mode can be inserted into measurements. This allows the voltage-controlled oscillator to be controlled during measurements using a calibration that was performed only a short time ago, thereby improving accuracy. Furthermore, particularly fast calibration, for example, depending on temperature or other variable environmental parameters, is possible by executing the calibration via the FPGA.

[0026] Within the scope of the invention, it may be advantageous that the measurement of the control characteristic curve includes at least one

[0027] - Programming a digital output of transmission frequencies, especially through the FPGA,

[0028] - Waiting for a settling of a phase-locked loop comprising at least the voltage-controlled oscillator, a frequency synthesizer, a low-pass filter, an analog multiplexer or a summation point, in particular by the FPGA

[0029] - Acquisition of control voltages of the voltage-controlled oscillator corresponding to the transmission frequencies, in particular by the FPGA

[0030] - Receiving the control voltages in the Field Programmable Gate Array or

[0031] - Providing the control voltages as a digital output signal at an output interface of the Field Programmable Gate Array.

[0032] Programming a digital output of transmit frequencies can be understood as the process of creating digital instructions for generating transmit frequencies. Programming can be performed by at least the FPGA or a processor.

[0033] Waiting for a settling of a phase-locked loop (also called PLL), which comprises at least the voltage-controlled oscillator, a frequency synthesizer, a low-pass filter or an analog multiplexer, can be designed to effect a temporal adaptation and / or stabilization of the phase-locked loop.

[0034] Acquiring control voltages from the voltage-controlled oscillator that correspond to the transmit frequencies can be understood as measuring the electrical voltages that control the voltage-controlled oscillator. Acquiring these voltages allows the oscillator's parameters to be initially determined and, if necessary, later monitored, to ensure that the generated frequencies meet the requirements. When receiving the control voltages in the field-programmable gate array (FPGA), the FPGA can at least receive, further process, store, or buffer the acquired control voltages from the voltage-controlled oscillator.

[0035] It can be provided that the VCO control voltages are provided as a digital signal at an output interface of the FPGA, so that they can at least be received, further processed, or used by other components, in particular a processor. This can be used, for example, to control other modules or for communication with other parts of a larger system.

[0036] Within the scope of the invention, it is conceivable that measurement parameters for measuring the control characteristic are stored in a register set of the field programmable gate array, wherein the measurement parameters in particular comprise at least one transmission frequency, a control word of a frequency synthesizer for a transmission frequency, a settling time, or a number of control voltages per transmission frequency to be recorded after settling. By storing the measurement parameters in a register set of the FPGA, access to this data is available quickly and efficiently. Furthermore, the integration of measurement parameters into the register set of the FPGA enables a compact hardware solution. Storing the measurement parameters in the register set of the FPGA reduces the need for external storage devices and facilitates implementation on a single FPGA platform.

[0037] Within the scope of the invention, it can be provided that, when measuring the control characteristic, transmission frequencies are set at least once, in particular in an ascending / descending and / or descending / increasing sequence. A simple measurement can be performed particularly quickly. It can be provided that the measurement is performed at least twice. This can increase the accuracy of the measurement. Furthermore, by performing the measurement in an ascending / descending and / or descending / increasing sequence, drifts can be taken into account particularly effectively, thus increasing the measurement accuracy.

[0038] It is also conceivable to average the recorded control voltages per transmission frequency to obtain an averaged control voltage. This averaging reduces the importance of individual, particularly error-prone measurement points, thereby improving the accuracy of the measurement.

[0039] It is also conceivable that measuring an operating point of the control characteristic curve takes less than 20 ms, especially less than 10 ms. Particularly fast measurement allows, on the one hand, the calibration mode to be inserted even during regular operation of the radar sensor module, allowing current calibration data to be used. On the other hand, complex measurements involving environmental variables, such as temperature and pressure, can be performed particularly quickly. This allows many measurement points to be recorded in a short amount of time, thus increasing the accuracy of the measurement.

[0040] Within the scope of the invention, it is optionally possible to provide for calibration of the control of the voltage-controlled oscillator, wherein in particular fewer than fifteen, in particular exactly three, different control voltages of a control characteristic of the voltage-controlled oscillator are used to determine the control characteristic in the vicinity of an operating point. By limiting the number of control voltages, it is possible to perform the measurement particularly quickly. By limiting the number to three control voltages, the determined values ​​can be converted particularly quickly and efficiently into a complete control characteristic by fitting a quadratic function, which assigns an output of the voltage-controlled oscillator to each possible input voltage.

[0041] Furthermore, within the scope of the invention, it can be provided that an automatic measurement of the entire characteristic curve of the voltage-controlled oscillator is provided by the FPGA, wherein in particular more than three different control voltages of the control characteristic curve of the voltage-controlled oscillator are used and / or that the measurement of the control voltages of the characteristic curve of the voltage-controlled oscillator is carried out deterministically and with quartz precision and / or that determined values ​​are used to determine an aging drift of the oscillator over the lifetime of the oscillator. The automated measurement of the entire characteristic curve enables fast and precise calibration both during production and in field use. Accuracy is further increased by a large number (>3) of control voltages. Statements about the aging state of the transmit oscillator can also be made at any time.With regard to the present invention, it is conceivable that the radar wave is generated by a modulation method, in particular at least by an FSK4 sideband modulation method, a frequency modulated continuous wave method, or a pseudo-random noise method, after calibration.

[0042] FSK4 (Four-State Frequency Shift Keying) is a modulation method that uses four different frequencies for data transmission. In a sideband modulation technique, the frequency changes in a predefined pattern to represent different symbols or data bits. One advantage of this method is its efficiency in transmitting data over channels with limited bandwidth. By utilizing sidebands, FSK4 can offer higher spectral efficiency compared to other modulation types.

[0043] The frequency-modulated continuous wave method can be thought of as a form of frequency modulation in which a carrier signal is continuously modulated. The advantage of this method lies in its robustness to interference and noise. By continuously varying the carrier frequency, FM systems can offer better noise suppression.

[0044] The pseudorandom noise method refers to the use of pseudorandom sequences. The advantage of this method lies in its ability to generate a broadband signal with specific properties. Pseudorandom sequences can have a pseudorandomized distribution and enable efficient use of the spectral bandwidth. The pseudorandom noise method offers advantages in terms of resilience to interference.

[0045] Furthermore, it is conceivable that the calibration mode is also activated during the detection of an environment and / or that a temperature characteristic mode is provided, in which the measurement of a control characteristic takes place in the calibration mode for a designated temperature operating range of the radar sensor module. This allows the measurement to be carried out with a calibration recorded promptly, thereby improving accuracy. In the temperature characteristic mode, the advantage is achieved that a temperature characteristic can be recorded quickly yet with great accuracy. The above object is further achieved by a radar sensor module according to the invention for measuring an environment, in particular for carrying out a method according to the invention, comprising:

[0046] - a voltage-controlled oscillator which generates a radar wave to measure the environment in a measuring mode and whose control characteristic can be measured in a calibration mode,

[0047] - a field programmable gate array, which controls the voltage-controlled oscillator and, in a measuring mode, pre-processes the radar echo generated by the radar wave in the environment, whereby the field programmable gate array controls the voltage-controlled oscillator both in the measuring mode and in the calibration mode, in the measuring mode practically directly, in the calibration mode indirectly via the frequency synthesizer.

[0048] In other words, the radar sensor assembly can be designed to carry out a method according to the invention.

[0049] This results in the same advantages with regard to a radar sensor assembly according to the invention as have already been described with regard to a method according to the invention.

[0050] Within the scope of the invention, it may be advantageous to further provide a phase-locked loop comprising at least the voltage-controlled oscillator, a frequency synthesizer, a low-pass filter, an analog multiplexer, or a summing point. In particular, the phase-locked loop comprises separate hardware components from the field-programmable gate array. The separate phase-locked loop allows for particularly precise provision of the carrier frequency for the radar antenna.

[0051] Within the scope of the invention, it is conceivable that the field-programmable gate array is connected to the voltage-controlled oscillator, in particular to the phase-locked loop, via at least one digital-to-analog converter or analog-to-digital converter, in particular one separate from the field-programmable gate array. Several digital-to-analog converters can also be provided, in particular a further digital-to-analog converter connected between the FPGA and the summing point. This allows for the installation of particularly precise or more cost-effective converters, depending on the requirements, while maintaining the functionality of the FPGA.

[0052] The above object is further achieved by a computer program product according to the invention, comprising instructions which, when the program is executed by a computer, in particular by a field programmable gate array of a radar sensor assembly according to the invention, cause the computer to carry out a method according to the invention.

[0053] This results in the same advantages with regard to a computer program product according to the invention as have already been described with regard to a method according to the invention and / or a radar sensor assembly according to the invention.

[0054] The above object is further achieved by a computer-readable storage medium according to the invention, comprising instructions which, when the program is executed by a computer, in particular by a field programmable gate array of a radar sensor assembly according to the invention, cause the computer to carry out a method according to the invention.

[0055] This results in the same advantages with respect to a computer-readable storage medium according to the invention as have already been described with respect to a method according to the invention and / or a radar sensor assembly according to the invention and / or a computer program product according to the invention.

[0056] Further advantages, features, and details of the invention will become apparent from the following description, in which several embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. These schematically show:

[0057] Figure 1 shows a sequence with measurement mode, calibration mode and temperature characteristic mode and

[0058] Figure 2 shows a radar sensor assembly according to the invention. In the following figures, identical reference numerals are used for the same technical features, even in different embodiments.

[0059] Fig. 1 shows an example of a possible sequence with which measurement mode I, calibration mode II and temperature characteristic mode III of the radar sensor assembly 100 can be changed. For example, during production, a temperature characteristic mode III could first be carried out. A calibration mode II could also be carried out during production. This would provide a basic calibration at the factory which is valid for different temperatures. However, both modes can in principle also be provided after production. After the radar sensor assembly 100 has been manufactured, it can then be installed, for example. In the installed state, it is then possible to change to measurement mode I and the radar sensor assembly 100 can be operated in this mode. It can also be provided to change to calibration mode II or temperature characteristic mode III directly after installation in order to obtain a fresh calibration.It may also be provided to switch repeatedly between measuring mode I, calibration mode II and temperature characteristic mode III, in particular between measuring mode I and calibration mode II, even during regular operation.

[0060] The method according to the invention for operating a radar sensor assembly 100 provides for measuring an environment in a measuring mode I, wherein a voltage-controlled oscillator 110 generates a radar wave and the radar echo generated by the radar wave in the environment is detected, as well as measuring a control characteristic of the voltage-controlled oscillator 110 in a calibration mode II, wherein the voltage-controlled oscillator 110 is controlled by a field programmable gate array 120 in both the measuring mode I and the calibration mode II.

[0061] Overall, the method according to the invention achieves the advantage that radar waves can be emitted that correspond as closely as possible to a specified value. Because the voltage-controlled oscillator 110 is controlled by the FPGA in both measurement mode I and calibration mode II, the modes can run quickly and deterministically. In particular, calibration mode II can be inserted into measurements. This allows the voltage-controlled oscillator 110 to be controlled during measurements using a calibration that occurred only a short time ago, thereby improving accuracy. Furthermore, particularly fast calibration, for example, depending on temperature or other variable environmental parameters, is possible by executing the calibration via the FPGA.

[0062] In addition to the method according to the invention, a radar sensor assembly 100 according to the invention for measuring an environment, in particular for carrying out a method according to the invention, is also proposed. A radar sensor assembly 100 according to the invention is shown in Fig. 2. According to the invention, the radar sensor assembly 100 has a voltage-controlled oscillator 110, which generates a radar wave for measuring the environment in a measurement mode I and whose control characteristic can be measured in a calibration mode II, as well as a field-programmable gate array 120, which controls the voltage-controlled oscillator 110 and, in a measurement mode I, preprocesses the radar echo generated by the radar wave in the environment. The field-programmable gate array 120 controls the voltage-controlled oscillator 110 both in measurement mode I and, in particular indirectly via the frequency synthesizer 130, in calibration mode II.

[0063] In other words, the radar sensor assembly 100 can be designed to carry out a method according to the invention.

[0064] This results in the same advantages with respect to a radar sensor assembly 100 according to the invention as have already been described with respect to a method according to the invention.

[0065] Fig. 2 shows both an input interface and an output interface on the field programmable gate array 120. The field programmable gate array 120 can exchange data with a processor (not shown) via these interfaces. This processor can be configured to control the field programmable gate array 120 or to further process the data output by the field programmable gate array 120. Furthermore, the processor can also be part of the radar sensor assembly 100 according to the invention.

[0066] Within the scope of the invention, it may be advantageous to further provide a phase-locked loop which comprises at least the voltage-controlled oscillator 110, a frequency synthesizer 130, a low-pass filter 140, an analog multiplexer 150, or a summing point 180, wherein the phase-locked loop, in particular, has hardware components separate from the field-programmable gate array 120. The separate phase-locked loop allows for particularly precise provision of the signal for the radar antenna. Within the scope of the invention, it is conceivable for the field-programmable gate array 120 to be connected to the voltage-controlled oscillator 110, in particular to the phase-locked loop, via at least one or more digital-to-analog converters 160 and 161 or analog-to-digital converters 170, in particular separate from the field-programmable gate array 120.This allows particularly precise or more cost-effective converters to be installed depending on the requirements, while maintaining the functionality of the FPGA.

[0067] The above explanation of the embodiments describes the present invention exclusively by way of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention.

[0068] Reference symbols

[0069] 100 radar sensor assembly

[0070] 110 Oscillator

[0071] 120 Field Programmable Gate Array (FPGA)

[0072] 121 Output interface

[0073] 122 Input interface

[0074] 130 frequency synthesizers

[0075] 140 low-pass filters

[0076] 150 multiplexers

[0077] 160 digital-analog converters

[0078] 161 digital-analog converters

[0079] 170 analog-digital converters

[0080] 180 summation / modulation point

[0081] I Measuring mode

[0082] II Calibration mode

[0083] III Temperature characteristic mode

Claims

Patent claims 1. A method for operating a radar sensor assembly (100), comprising: - measuring an environment in a measuring mode (I), wherein a voltage-controlled oscillator (110) generates a radar wave and the radar echo generated by the radar wave on the environment is detected, - Measuring a control characteristic of the voltage-controlled oscillator (110) in a calibration mode (II), wherein the voltage-controlled oscillator (110) is controlled by a field-programmable gate array (120) in both the measurement mode (I) and the calibration mode (II).

2. Method according to claim 1, characterized in that the measurement of the control characteristic curve comprises at least one - Programming a digital output of transmission frequencies, - Waiting for a settling of a phase-locked loop comprising at least the voltage-controlled oscillator (110), a frequency synthesizer (130), a low-pass filter (140), an analog multiplexer (150) or a summing point (180) - detecting control voltages of the voltage-controlled oscillator (110) corresponding to the transmission frequencies, - Receiving the control voltages in the Field Programmable Gate Array (120), or - providing the control voltages as a digital output signal at an output interface (121) of the field programmable gate array (120).

3. Method according to claim 1 or 2, characterized in that for measuring the control characteristic, measurement parameters are stored in a register set of the field programmable gate array (120), wherein in particular the measurement parameters comprise at least one transmission frequency, a control word of a frequency synthesizer (130) for a transmission frequency, a settling time or a number of control voltages per transmission frequency which are to be detected after the settling.

4. Method according to one of the preceding claims, characterized in that when measuring the control characteristic, transmission frequencies are set at least once, in particular ascending / descending and / or descending / increasing.

5. Method according to one of the preceding claims, characterized in that an averaging of the detected control voltages per transmission frequency is provided in order to detect an averaged control voltage.

6. Method according to one of the preceding claims, characterized in that the measurement of an operating point of the control characteristic takes less than 20 ms, in particular less than 10 ms.

7. Method according to one of the preceding claims, characterized in that a calibration of the control of the voltage-controlled oscillator (110) is provided, wherein in particular less than fifteen, in particular exactly three, different control voltages of a control characteristic of the voltage-controlled oscillator (110) are used to determine the control characteristic in an environment of an operating point.

8. Method according to one of the preceding claims, characterized in that an automatic measurement of the entire characteristic curve of the voltage-controlled oscillator (110) is provided by the FPGA, wherein in particular more than three different control voltages of the control characteristic curve of the voltage-controlled oscillator (110) are used and / or that the measurement of the control voltages of the characteristic curve of the voltage-controlled oscillator (110) is carried out deterministically and with quartz precision and / or that determined values ​​for Determination of an aging drift of the oscillator (110) over the lifetime of the oscillator (110).

9. Method according to one of the preceding claims, characterized in that the radar wave is generated by a modulation method, in particular at least by an FSK4 sideband modulation method, a frequency-modulated continuous wave method, or a pseudo-random noise method, after calibration.

10. Method according to one of the preceding claims, characterized in that the calibration mode (II) is also activated during the detection of an environment and / or that a temperature characteristic mode (III) is provided, in which the measurement of a control characteristic in the calibration mode (II) takes place for an intended temperature application range of the radar sensor assembly (100).

11. Radar sensor assembly (100) for measuring an environment, in particular for carrying out a method according to one of claims 1 to 10, comprising: - a voltage-controlled oscillator (110) which generates a radar wave for measuring the environment in a measuring mode (I) and whose control characteristic can be measured in a calibration mode (II), - a field programmable gate array (120) which controls the voltage-controlled oscillator (110) and preprocesses the radar echo generated by the radar wave in the environment in a measuring mode (I), wherein the field programmable gate array (120) controls the voltage-controlled oscillator (110) both in the measuring mode (I) and in the calibration mode (II).

12. Radar sensor assembly (100) according to claim 11, characterized in that a phase-locked loop is further provided, which comprises at least the voltage-controlled oscillator (110), a frequency synthesizer (130), a low-pass filter (140), an analog multiplexer (150) or a summation point (180). wherein in particular the phase locked loop has separate hardware components from the field programmable gate array (120).

13. Radar sensor assembly (100) according to claim 11 or 12, characterized in that the field programmable gate array (120) is connected to the voltage-controlled oscillator (110), in particular to the phase-locked loop, via at least one digital-analog converter (160) or analog-digital converter (170), in particular separate from the field programmable gate array (120).

14. A computer program product comprising instructions which, when the program is executed by a computer, in particular by a field programmable gate array (120) of a radar sensor assembly (100) according to claims 11 to 13, cause the computer to carry out a method according to one of claims 1 to 10.

15. Computer-readable storage medium comprising instructions which, when executed by a computer, in particular by a field programmable gate array (120) of a radar sensor assembly (100) according to claims 11 to 13, cause the computer to carry out a method according to one of claims 1 to 10.

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