Object simulator for a sensor for object detection and method for simulating an object
The object simulator transforms and emulates sensor signals within a working band to simulate object reflections, addressing the inefficiencies of traditional testing methods and enabling effective virtual testing of object detection sensors.
Patent Information
- Application Number
- PCT/EP2025/065259
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-09
- Filing Date
- 2025-06-03
- Publication Date
- 2026-01-15
AI Technical Summary
Existing object detection sensors, such as radar and LiDAR sensors, require extensive field testing which is costly and inefficient, and there is a need for a cost-effective method to simulate various test scenarios without actual vehicle drives.
An object simulator that transforms sensor signals into a working band for processing, modifies these signals to emulate reflections from simulated objects, and transmits them back to the sensor, allowing virtual testing of object detection functions.
Enables cost-effective and comprehensive testing of object detection sensors in various scenarios, eliminating the need for physical test drives and reducing hardware complexity by processing signals within a limited bandwidth.
Smart Images
Figure EP2025065259_15012026_PF_FP_ABST
Abstract
Description
[0001] OBJECT SIMULATOR FOR A SENSOR FOR OBJECT DETECTION AND METHOD FOR SIMULATING AN OBJECT
[0002] Technical field
[0003] The application relates to an object simulator for a sensor for object detection and a method for simulating an object for a sensor for object detection.
[0004] background
[0005] An object detection sensor can, for example, be designed as a vehicle sensor that operates using electromagnetic waves. Examples of such vehicle sensors are radar sensors or LiDAR sensors. An object simulator for an object detection sensor can be used, for example, when testing such a vehicle sensor.
[0006] Overview
[0007] An object simulator for an object detection sensor exhibits:
[0008] • a receiver configured to receive a first signal emitted by the sensor and to combine it with a first carrier signal to form a first working signal, such that the first signal is transformed over its frequency bandwidth into a working band for the first working signal, the frequency bandwidth being greater than the working band,
[0009] • an object generator configured to modify the first work signal in the workband to a second work signal depending on at least one object to be simulated,
[0010] • a transmitter configured to generate a second signal depending on the second working signal and a second carrier signal, wherein the second working signal is transformed from the working band into the frequency bandwidth for the second signal, and wherein the transmitter is further configured to transmit the second signal,
[0011] • wherein the second signal emulates a reflection of the first signal at the at least one object to be simulated. The second signal is intended for reception by the sensor and is designed such that it is perceptible by the sensor as a reflection of the first signal at the at least one object to be simulated. The sensor is, for example, arranged in a mount of a test setup, the test setup containing the object simulator and configured for testing the sensor. The emulation of the reflection thus manipulates the first signal in the same way as the reflection at the object to be simulated would.
[0012] A method for simulating an object for an object detection sensor exhibits:
[0013] • Receiving a first signal emitted by the sensor, wherein the first signal is combined with a first carrier signal to form a first working signal, such that the first signal is transformed over its frequency bandwidth into a working band for the first working signal,
[0014] • Changing the first work signal to a second work signal in the work band depending on at least one object to be simulated,
[0015] • Sending a second signal, wherein the second working signal is combined with a second carrier signal in such a way that the second working signal is transformed from the working band into the frequency bandwidth for the second signal,
[0016] • where the second signal emulates a reflection of the first signal at the at least one object to be simulated.
[0017] The second signal is intended for reception by the sensor, which is located, for example, in the receiver of the test setup.
[0018] The transformation of the first signal across its frequency bandwidth into the working band for the first operating signal includes, for example, mapping the first operating signal onto the working band in such a way that, without significant information loss, it is sufficient to process the first operating signal only within the working band. This means that the first operating signal is processed within the working band, and that sufficient information is contained within the working band to perform the object simulation for the sensor.
[0019] The modification of the first working signal to the second working signal is achieved, for example, by manipulating the first working signal in the working band so that the second signal generated from the second working signal is perceived by the sensor for object detection as the described reflection on at least one object.
[0020] In some embodiments, the second operating signal can correspond to the first operating signal. Depending on the object to be simulated, the emulation of the object can then be performed by the second carrier signal. This is possible as an alternative or in addition to the emulation of the object to be simulated by the object generator.
[0021] The object simulator allows object detection sensors, such as radar or LiDAR sensors, to be tested in the laboratory under a wide variety of test scenarios. This eliminates the need for test drives of vehicles equipped with the sensor. The object simulator can be integrated into a test setup that simulates the sensor's and / or vehicle's environment. In this test environment, the object simulator reacts to the initial signals emitted by the sensor in a virtual setting, thus acting as a real-world environment for the sensor.
[0022] The described object simulator for the object detection sensor can be built cost-effectively, since the bandwidth of the working signals to be processed in the object simulator is limited to the bandwidth of the working band, thus eliminating the need for processing in a wide frequency band.
[0023] The described method for simulating the object for the sensor for object detection can be implemented cost-effectively, since the manipulation of the first working signal to the second working signal can take place in the working band and processing in a wide frequency band can be omitted.
[0024] The first signal, which can have a wide frequency bandwidth, can be more easily processed by the object simulator through transformation into the working band. The necessary hardware can be designed more simply than if frequencies with a larger bandwidth had to be processed. This allows the object simulator to be designed more cost-effectively and the process to be implemented more cheaply.
[0025] The object simulator, for example, is a device that has the following components: a receiver for the first signal, the object generator, and a transmitter for sending the second signal, so that this modified second signal can be interpreted by the sensor as a first signal that was reflected by one or more objects.
[0026] If the sensor is a radar sensor, both the receiver and the transmitter each have a high-frequency section that converts the first signal into the first operating signal within the working frequency range, and transforms the second signal into the second signal within the high-frequency range. The second operating signal also lies within the working frequency range. The high-frequency range for the first and second signals is higher than the operating frequency range. The first and second signals have a frequency bandwidth of [missing information]. This means that the first and second signals contain frequencies that lie within the frequency range of [missing information]. The frequency bandwidth is greater than the bandwidth of the operating frequency range.
[0027] If the sensor is a LiDAR sensor, the receiver and transmitter use opto-electrical and electro-optical converters, respectively. This means the first signal is an optical signal, which is first converted into a high-frequency signal (i.e., the frequency bandwidth) and then into the first operating signal within the operating band. Similarly, the transmitter first transforms the second operating signal into the frequency bandwidth, and then the electro-optical converter transforms it into the second signal as an optical signal. Examples of opto-electrical converters include optical receivers such as PIN diodes or photomultiplier tubes. Examples of electro-optical converters include laser diodes.
[0028] The first signal could, for example, be the emitted probe signal from a radar or LiDAR sensor. This probe signal could, for example, be modulated. The frequency bandwidth of the first signal corresponds to the frequency bandwidth of the probe signal.
[0029] The working band is the frequency range of the first and second operating signals. The operating signals themselves can be modulated. The working band can, for example, correspond to a baseband. In the case of the baseband, the lower frequency can be at or close to 0 Hz.
[0030] Object detection by the sensor is achieved using the emitted first signal, e.g., the sensor's touch signal, and the received second signal. The second signal is perceived by the sensor as a reflection from an object. Object detection can then be performed by the sensor by evaluating the first and second signals. Object detection can include, for example, determining the object's location, but also its movement, i.e., its velocity, acceleration, and direction of movement. It can also refer to the object's size, which, in the case of a radar sensor, can be determined, for example, as a function of a radar cross-section.
[0031] The object generator adds a corresponding signal to the first operating signal, based on the number, movement, and, if applicable, shape of the objects to be simulated. This signal represents the reflection or refraction that these objects would produce. In the context of this application, this corresponds to modifying the first operating signal into the second operating signal.
[0032] Object simulation allows sensors like radar or LiDAR to be virtually tested in various scenarios with a multitude of objects, without requiring a complex test setup. It also enables testing of object detection functions. Furthermore, it's possible to test how a vehicle reacts to detection, for example, in semi- or fully automated driving modes.
[0033] The first working signal is the output signal of the receiver and the second working signal is the output signal of the object generator and an input signal of the transmitter.
[0034] The transformation of the first signal from its frequency with the frequency bandwidth to the narrower operating band is a frequency conversion, e.g., by demodulation using a first carrier signal. The same applies to the transformation of the second operating signal, e.g., by modulation with a second carrier signal, from the narrower operating band to its frequency with the frequency bandwidth.
[0035] Carrier signals are signals that can be generated using, for example, oscillators and other frequency generation circuits. These carrier signals can be signals such as a sine wave or a superposition of several sine waves. When transforming the first signal from its frequency with its bandwidth to the working band, a multiplicative combination of the first signal and the first carrier signal can take place. For this purpose, the first carrier signal can have multiple frequencies. The frequencies of the carrier signal are then configured such that the frequency bandwidth of the first signal is transformed into the working band. The same applies to transforming the second working signal into the frequency bandwidth of the second signal.
[0036] In one embodiment, the first and second signals each consist of a high-frequency signal in the microwave range. This can be particularly relevant when using the sensor as a radar sensor, but also when a LiDAR sensor is used, in which case the high-frequency signal is modulated onto an optical signal. The microwave range refers, for example, to electromagnetic waves that propagate at a frequency of 1 to 300 GHz.
[0037] In embodiments, the first and second signals are frequency-modulated, in particular frequency-modulated over a modulation bandwidth, wherein the modulation bandwidth is in particular at least twice as wide as the operating band. The frequency bandwidth is greater than or equal to the modulation bandwidth. In radar technology, especially for applications in road traffic, continuous-wave radars with frequency modulation (FMCW) have proven suitable. The first signal, with, for example, a constant amplitude, is transmitted as the keying signal and periodically sweeps through a frequency range. This sweeping through the frequency range is called a chirp. The frequency of the chirp thus sweeps through the modulation bandwidth. At least two chirps can follow each other directly, or a pause can be provided between them. The frequency bandwidth of the first and second signals can therefore be, for example,correspond to the modulation bandwidth of a chirp of the FMCW modulated key signal.
[0038] LiDAR sensors with modulated touch signals are also known. The object generator and the method can be applied to them in the same way.
[0039] In one embodiment, the object generator is configured to modify the first operating signal with respect to phase, amplitude, and / or frequency and output it as a second operating signal. This allows the effect of the reflection of the first signal on one or more virtual objects to be realized by modifying the first signal and outputting the second signal.
[0040] Furthermore, the receiver may be configured to combine the first signal with the first carrier signal to form the first working signal, where the first carrier signal has a plurality of carrier frequencies. This allows individual frequency segments from the first signal, particularly across the entire frequency bandwidth, to be transformed into the working band.
[0041] Furthermore, it is possible that the transmitter is configured to combine the second working signal with the second carrier signal to form the second signal, where the second carrier signal contains the majority of the carrier frequencies. This allows the second signal to be generated from the working band with its entire frequency bandwidth.
[0042] It can be provided that the majority of the carrier frequencies, with their respective bands, cover the frequency bandwidth. This allows the entire frequency bandwidth to be transformed into and out of the working band. In some embodiments, a chirp can be transformed section by section into the working band across the modulation bandwidth, e.g., the frequency bandwidth, so that the chirp is divided across the frequency bandwidth into many chirps, each with a narrower frequency band within the working band.
[0043] In one embodiment, the object simulator can have a carrier signal generator that includes a power divider, wherein the first and second carrier signals can be derived from a total carrier signal via the power divider. This power divider can be implemented, for example, via a resistor network, in particular an ohmic divider.
[0044] In some embodiments, the carrier signal generator can have a separate frequency generation circuit for each carrier frequency, with the respective output signals of the individual frequency generation circuits being combined into the overall carrier signal via a power combiner. A directional coupler can be used as the power combiner.
[0045] In embodiments, the carrier signal generator can comprise a first frequency generation circuit and a second frequency generation circuit, wherein a first output signal of the first frequency generation circuit with a first frequency can be transformed by means of a harmonic generation circuit to a second output signal with several multiples of the first frequency, and wherein a third output signal with a second frequency of the second frequency generation circuit can be combined with the second output signal to form the overall carrier signal. Harmonics of a fundamental frequency are overtones, i.e., integer multiples of the fundamental frequency. Circuits with nonlinearity in a characteristic curve, such as diode characteristics, can typically be used to generate harmonics.
[0046] It is possible for the first and second carrier signals to be essentially the same or frequency-shifted versions of the same signal. This allows for symmetry in the design of the object simulator.
[0047] List of characters
[0048] Examples of the application's implementation are shown in the figures and are explained in more detail in the following description.
[0049] They show
[0050] Fig. 1 schematically shows a test setup as a block diagram,
[0051] Fig. 2 schematically shows a first block diagram of the object simulator,
[0052] Fig. 3 is a diagram illustrating the carrier signals,
[0053] Fig. 4 schematically shows a frequency-time diagram to represent a chirp,
[0054] Fig. 5 schematically shows another frequency-time diagram to represent the first operating signal,
[0055] Fig. 6 schematically shows another frequency-time diagram to represent the second signal,
[0056] Fig. 7 schematically shows a block diagram illustrating the generation of the carrier signals,
[0057] Fig. 8 schematically shows another block diagram to illustrate the generation of the carrier signals,
[0058] Fig. 9 shows a flowchart of the process and
[0059] Fig. 10 schematically shows an overview of the signals with working band.
[0060] The same reference symbols are used in the figures for identical or similar elements. The representations in the figures cannot be to scale. Figure description
[0061] Figure 1 shows a test setup 20 with an object simulator 10 that simulates at least one object for a sensor 14 for object detection. The sensor 14 is, for example, arranged in a mount 12. The mount 12 can hold the sensor 14 in a predefined space for testing with the object simulator 10, or the mount 12 can be, for example, attached to a vehicle and hold the sensor 14 in its intended position. The mount 12 specifies the location where the sensor 14 can be positioned in the test setup 20 for testing purposes. As shown in Figure 1, the mount 12 can be designed as an environment that at least partially surrounds the sensor 14. Alternatively, the mount 12 can be designed differently and, for example, simply define the spatial location within the test environment 20 where the sensor 14 can be positioned.
[0062] The sensor 14 can be, for example, a radar or a LiDAR. The mounting 12 can be made of plastic, metal, and / or other materials. The mounting 12 can also have electrical interfaces for the sensor 14, so that the sensor 14 can be easily connected for operation.
[0063] The sensor 14 emits a first signal SI, e.g., in the form of a touch signal, which is received by the object simulator 10 via its first antenna 16. If the sensor 14 is configured as a radar sensor, the first antenna 16 can be designed for receiving high-frequency signals. If the sensor 14 is configured as a LiDAR sensor, the first antenna 16 can be configured as an opto-electrical converter with receiving optics. The receiving optics can, for example, be lenses that direct the received signal S1 onto PIN diodes, which convert the optical signal S1 into an electrical signal.
[0064] The object simulator 10 converts the first signal S1 into a first working signal Al, which is processed in the working band. From the first working signal Al, a second working signal A2 is generated in the working band. From the second working signal A2, the object simulator 10 then generates a second signal S2, which is transmitted via a second antenna 18.
[0065] The second antenna 18, when a radar sensor is used as sensor 14, is an antenna for transmitting high-frequency signals, e.g., a horn, patch, or parabolic antenna. If a LiDAR sensor is used as sensor 14, electro-optical transducers can be used as the second antenna 18. An example is laser diodes with appropriate beam-shaping optics.
[0066] The first and second antennas 16, 18 can also be monostatic. In this case, the first and second antennas 16, 18 are the same single antenna, which – in the case of a radar sensor – is connected to a circulator or coupler.
[0067] Figure 2 schematically shows a block diagram of the setup of an object simulator 10. The first signal S1 is received by a receiver RX. The receiver RX has a first antenna 16 for receiving the first signal S1. The received first signal S1 is fed to a first mixer M1, which combines the first signal S1 with a first carrier signal TS1, for example, multiplicatively, to form the first working signal Al. In this process, the first signal S1 is transformed across its frequency bandwidth 42 into the working band for the first working signal Al.
[0068] The frequency bandwidth 42 is larger than the frequency range of the working band. For example, the first signal S1 has a frequency bandwidth of 42 in a high-frequency range, preferably in a microwave range.
[0069] The first antennas 16 and the first mixer Ml are components of a receiver RX. Other components, not shown, may be present, such as filters (e.g., bandpass filters) and amplifiers to process the received initial signal S1 for further processing. These components are omitted here for the sake of simplicity.
[0070] The first mixer Ml uses, for example, a diode or a transistor for the interconnection. Combinations of active and passive, or purely active, electrical and electronic components are also possible. The use of a non-linear characteristic curve is advantageous, which may involve a single component such as a diode or a transistor, or several such and / or other components combined.
[0071] The first carrier signal TS1 is generated by a carrier signal generator 26 and, for example, has a plurality of carriers with different frequencies spaced apart IF_bw. This makes it possible to transform a chirp into individual sub-chirps in the working band in the case of frequency modulation, as in an FMCW radar. This simplifies the processing of the first and second working signals A1 and A2.
[0072] The carrier signal generator 26 can, for example, be a local oscillator with one or more frequency generation circuits. The frequency generation circuits can multiply the frequency, particularly by integer values. This can be achieved, for example, through a multiplicative operation with itself, as in a mixer. Since the carrier signal generator 26 can also generate the second carrier signal TS2, it can also include a power divider if the first and second carrier signals TS2 are to be, for example, the same or at least similar. This similarity can be expressed, for example, by the same frequencies and similar amplitudes of the carriers. For instance, the second carrier signal TS2 can have a plurality of carriers that have the same spacing IF_bw between them as the first carrier signal TS1.
[0073] The first operating signal Al is fed to the object generator 22, which modifies the first operating signal Al into a second operating signal A2 such that the second operating signal A2 is configured to indicate one or more reflections of the first signal S1 at one or more simulated objects. These simulated objects can be stored in the object generator 22 itself, or they can be generated based on object information 24. The object information 24 can be supplied to the object simulator 10 externally and contains information about the type and / or motion state of the object to be simulated. The object information 24 can fully describe a given simulated object, or the object generator 22 can use it to modify existing object data to generate new or additional objects.This allows a user to access and define specific scenarios for testing sensor 14 that are not yet available in object simulator 10. The object information 24 can, for example, be received by the object simulator from another computing unit, which could be an FPGA, a processor, or similar device. Depending on the type of object being simulated, the first operating signal Al can correspond to the second operating signal A2. Changing the first operating signal Al to the second operating signal A2 can also simply involve forwarding the signal. The emulation of the simulated object can then be performed, for example, using the second carrier signal TS2.
[0074] In some embodiments, the object generator 22 can change the amplitude of the first operating signal Al, which emulates a property of the object to be simulated, namely the radar cross-section (RCS) of a radar sensor. Alternatively or additionally, properties of the simulated object relating to distance and / or velocity can be emulated by a second mixer M2 by mixing the second operating signal A2 with the second carrier signal TS2. Here, the second carrier signal TS2 can be set by the carrier signal generator depending on the object properties to be simulated, which may be contained in the object information 24. Alternatively or additionally, properties of the simulated object relating to distance and / or velocity can be emulated by delaying the operating signal Al in time.The time delay of the first work signal Al can be achieved, for example, by the object generator 22.
[0075] From the second operating signal A2, the object simulator 10 generates the second signal S2 depending on the second carrier signal TS2. The second operating signal A2 is transmitted to the second mixer M2, which preferably combines the second operating signal A2 multiplicatively with the second carrier signal TS2, so that the resulting second signal S2, with a frequency bandwidth of 42, lies within the frequency range used by the sensor 14. The second signal S2 thus generated is then transmitted to the sensor 14 via the second antenna 18.
[0076] The second antenna 18 and the second mixer M2 belong to the transmitter TX. For the sake of simplicity, other possible components of the transmitter TX, such as filters, bandpass filters and / or amplifiers for the second signal S2 or the second operating signal A2, are not shown in Figure 2.
[0077] Accordingly, for the sake of simplicity, the receiver RX, filters and amplifiers as well as any other possible elements are not shown in the drawing.
[0078] Figure 3 shows a diagram illustrating the possible characteristics of the first and second carrier signals TS1 and TS2. As examples, Figure 3 depicts frequencies F, 2F, ..., nF spaced equally apart IF_bw, representing the first and second carrier signals TS1 and TS2, respectively. It is possible for the carrier signals TS1 and TS2 to have more or fewer carriers than those shown. Advantageously, each frequency carrier has the same amplitude. However, it is possible for these frequency carriers to have different amplitudes. This can differentiate not only the carrier signals TS1 and TS2, but also the carriers within each of the respective carrier signals TS1 and TS2.
[0079] Figure 4 shows a frequency-time diagram illustrating a chirp that can be used in an FMCW radar. This is, for example, the first signal Sl that can be emitted by sensor 14 when configured as an FMCW radar. The chirp duration 40 is shown as a function of nT, and the frequency bandwidth 42 as a function of nF. The chirp duration and frequency bandwidth values shown in Figure 4 are for illustrative purposes only and can be any other suitable value. The slope also need not be as shown in Figure 4.
[0080] Figure 5 shows the first and second operating signals Al, A2 in a frequency-time diagram. It can be seen that the chirp from Figure 4 was transformed into a baseband 50 as the operating band and thus persists with the same slope as the chirp for each period 0, T ... nT up to the frequency F. The chirp of the first signal Sl was therefore transformed into the baseband 50 as the operating band in the first operating signal Al.
[0081] The illustration in Figure 5 is exemplary. The chirp of the first signal Sl shown in Figure 4, even when mixed down to the baseband 50, has the same duration as the first working signal Al. However, as the first working signal Al, the chirp is divided into several segments, each corresponding to the width of the working band. In Figure 5, the working band corresponds to the baseband 50 as an example.
[0082] Figure 6 shows, in a further frequency-time diagram, the signal components of the second signal S2 directly after the multiplicative combination of the second operating signal A2 with the second carrier signal TS2. Parallel to the solid line with the chirp duration 40, dashed lines can be seen, which can arise from the multiplicative combination in the second mixer M2. However, the sensor 14 filters out unwanted signals during reception. Alternatively, the unwanted signals can be filtered out in the transmitter TX. Figure 7 schematically shows, in a block diagram, an embodiment for the generation of the first and second carrier signals TS1, TS2 by the carrier signal generator 26. Respective frequency generation circuits 70.1, 70.2, ... 70.n generate the different frequency carriers. This can be done digitally and / or analogously. Oscillators and / or frequency multipliers can be used for this purpose.In the power combiner 70, these signals are combined to form the carrier total signal TSG. The carrier total signal TSG is fed to a power divider 72, which generates the first and second carrier signals TS1 and TS2 from it.
[0083] In the simplest case, resistor networks can be used for the power combiner 70 and the power divider 72. Directional couplers can be used, especially when high-frequency signals need to be combined or split.
[0084] Figure 8 shows an alternative embodiment of the carrier signal generator 26 in a further block diagram. A first frequency generation circuit 80.1 provides a first output signal AG1, which is fed to a harmonic generation circuit 80. The second output signal AG2 of the harmonic generation circuit 80 has harmonics of the first output signal AG1, i.e., multiples of the frequency of the first output signal AG1. The second output signal AG2 is filtered by filter 84 to remove unwanted signal components. The filtered second output signal AG2 is then fed to an equalizer 86. The equalizer 86 can include filtering, amplification, and / or attenuation of various frequency ranges.
[0085] The equalized and filtered second output signal AG2 is multiplicatively combined with a third output signal AG3 from a second frequency generation circuit 80.2. A nonlinearity such as the current-voltage characteristic of a diode can again be used for this multiplicative combination.
[0086] The product of this interaction is combined by a low-pass or high-pass filter 88 to form the total carrier signal TSG. The total carrier signal TSG is then fed to a power divider 82, which generates the first and second carrier signals TS1 and TS2.
[0087] Figure 9 shows a flowchart illustrating the procedure for simulating an object for sensor 14 for object detection. In process step 90, the first signal S1 emitted by sensor 14 is received by receiver RX. The first signal S1 is picked up by a first antenna 16.
[0088] In process step 91, the first signal S1 is converted in the receiver RX into the first working signal Al by combining it with the first carrier signal TS1, thereby converting the first signal S1 from its frequency bandwidth 42 into the working band. The frequency bandwidth 42 is larger than the frequency range of the first working signal Al in the working band.
[0089] In process step 92, the first operating signal Al is modified by an object generator 22 into a second operating signal A2 in the workband, depending on at least one object to be simulated, according to the object information 24. Depending on the object to be simulated, the modification can correspond to a forwarding, such that the second operating signal A2 at an output of the object generator 22 corresponds to, or essentially corresponds to, the first operating signal Al at an input of the object generator 22.
[0090] In process step 93, the second working signal A2 is combined with a second carrier signal TS2 in a transmitter TX, so that the second working signal A2 is transformed from the working band into the frequency range of the second signal S2 with a frequency bandwidth of 42. The frequency range of the first and second signals SI, S2 is the frequency range used by sensor 14.
[0091] In process step 94, the second signal S2 is transmitted by the transmitter TX, so that the sensor 14 can receive the second signal S2. The second signal S2 is designed such that the sensor 14 perceives the second signal S2 as a reflection of the first signal S1 from the at least one object to be simulated.
[0092] Figure 10 schematically depicts signals from another embodiment of the object simulator 10 and the method for simulating an object. A frequency-time diagram is shown, with frequency plotted on the ordinate and time on the abscissa.
[0093] The frequency-time diagram shows two regions. The upper region is the high-frequency region, which, for example, is 77 GHz for a radar sensor (sensor 14). The lower region is the operating frequency region between 100 and 500 MHz. In the example shown, the operating region has a bandwidth of 400 MHz. The high-frequency region and the operating region can also be at other frequencies, and the bandwidth of the operating region can also have different values.
[0094] The first signal S1 is shown as a dotted line. The corresponding second signal S2 is shown directly next to the first signal S1 with a solid line. The frequency bandwidth 42 of both the first and second signals S1 and S2 is 1 GHz.
[0095] The frequency difference f_doppler between the first and second signals
[0096] 51 and S2 can optionally be added to the first working signal Al in object generator 22 to generate the second working signal A2. This allows the object from which the first signal S1 is reflected to be emulated as the second signal.
[0097] 52 returns to sensor 14. Alternatively or additionally, the frequency difference f_doppler between the first carrier signal TS1 and the second carrier signal TS2 can be generated in the carrier signal generator 26. This embodiment is shown in Fig. 10. By mixing the second working signal A2 and the second carrier signal TS2 using the second mixer M2, the second signal S2 then exhibits this frequency difference f_doppler.
[0098] The spacing IF_bw between the carrier signals TS1 and TS2 is 500 MHz. This frequency spacing can also be adjusted to other suitable values. The spacing IF_bw should preferably be greater than the internal processing bandwidth of sensor 14, e.g., a radar sensor.
[0099] Within the operating range, the second operating signals A2 are shown as solid lines between 100 and 500 MHz, while the first operating signals Al are shown as dashed lines outside the operating range. The first operating signal Al is processed within the operating range, which is frequency-limited compared to the combined frequency bandwidth 42 of the first signal S1 and the second signal S2. Therefore, in the illustrated embodiment, only the frequency range between 100 and 500 MHz of the first operating signal S1 is processed. However, because the first carrier signal TS1 has multiple carriers, the information of the first operating signal outside the operating range is not lost but is available through the repetitions of the first operating signal Al within the operating range.
[0100] In the example shown, the first operating signal Al corresponds to the second operating signal A2. Therefore, no changes were added for emulation by the object generator 22. In other embodiments, the first operating signal Al may differ from the second operating signal A2, e.g., in amplitude, phase, and / or frequency. These differences can be added, in particular, by the object generator 22.
[0101] It can be seen that the first and second working signals Al, A2 can be processed in the working band, which is more frequency-limited than the frequency bandwidth 42 of the first signal S1 and the second signal S2. This allows the object simulator 10 to be designed cost-effectively.
[0102] The second signal S2 is generated from the second operating signal A2 by mixing it with the second carrier signal TS2 using the second mixer M2. Since the second carrier signal TS2 has multiple carriers, several second signals are generated, each with a frequency spacing IF_bw between the carriers of the second carrier signal TS2. The unwanted parts of the second signal S2, shown here with dashed lines, can be filtered out, for example, by filters. These filters can be located, for example, in the object simulator 10 and / or in the sensor 14. It is possible that the sensor 14 already has such filters to suppress unwanted received frequencies.
[0103] Reference symbol list
[0104] 10 Object Simulator
[0105] 12 recording
[0106] 14 Sensors for object detection
[0107] 16 first antenna
[0108] 18 second antenna
[0109] 20 Test setup
[0110] 22 Object Generator
[0111] 24 Object Information
[0112] 26 Carrier signal generator
[0113] 40 chirp duration
[0114] 42 Frequency bandwidth
[0115] 50 Baseband
[0116] 70 high-performance combination vehicles
[0117] 70.1, 70.2, ... 70. n Frequency generation circuit
[0118] 72 power dividers
[0119] 80 harmonic generation circuit
[0120] 80.1, 80.2 Frequency generation circuit
[0121] 82 power dividers
[0122] 84 filters
[0123] 86 equalizers
[0124] 88 High-pass or low-pass
[0125] S1 first signal
[0126] S2 second signal
[0127] First work signal
[0128] A2 second work signal
[0129] F, 2F, ... , nF Carrier frequencies
[0130] T, 2T, ... , nT period durations
[0131] ml first mixer
[0132] M2 second mixer
[0133] RX receiver
[0134] TX Transmitter
[0135] TS1 first carrier signal
[0136] TS 2 second carrier signal
[0137] TSG T carrier total signal t time f frequency
[0138] AG1 first output signal
[0139] AG2 second output signal
[0140] AG3 third output signal 90-94 process steps f_doppler Doppler frequency shift IF_bw carrier signal spacing
Claims
REQUIREMENTS 1. Object simulator (10) for a sensor (14) for object detection, the object simulator (10) comprising: a receiver (RX) configured to receive a first signal (Sl) emitted by the sensor (14) and to combine it with a first carrier signal (TS1) to form a first working signal (Al) such that the first signal (Sl) is transformed over its frequency bandwidth (42) into a working band for the first working signal (Al), wherein the frequency bandwidth (42) is larger than the working band; an object generator (22) configured to modify the first working signal (Al) in the working band to form a second working signal (A2) depending on at least one object to be simulated; a transmitter (TX) configured to generate a second signal (S2) depending on the second working signal (A2) and depending on a second carrier signal (TS2).wherein the second working signal (A2) from the working band is transformed into the frequency bandwidth (42) for the second signal (S2), wherein the transmitter (TX) is further configured to transmit the second signal (S2), wherein the second signal (S2) emulates a reflection of the first signal (Sl) at the at least one object to be simulated.
2. Object simulator according to claim 1, wherein the first and second signals (S1, S2) each comprise a high-frequency signal in the microwave range.
3. Object simulator according to claim 1 or 2, wherein the first and second signals (S1, S2) are frequency modulated, in particular frequency modulated over a modulation bandwidth, wherein the modulation bandwidth is in particular at least twice as wide as the working band, wherein the frequency bandwidth (42) is greater than or equal to the modulation bandwidth.
4. Object simulator according to one of the preceding claims, wherein the object generator (22) is configured to modify the first operating signal (Al) with respect to a phase, an amplitude and / or a frequency and output it as a second operating signal (A2).
5. Object simulator according to one of the preceding claims, wherein the receiver (RX) is configured to combine the first signal (Sl) with the first carrier signal (TS1) to form the first working signal (Al), wherein the first carrier signal (TS1) has a plurality of carrier frequencies (F, 2F, ... , nF).
6. Object simulator according to one of the preceding claims, wherein the transmitter (TS) is configured to combine the second working signal (A2) with the second carrier signal (TS2) to form the second signal (S2), wherein the second carrier signal (TS2) has the majority of the carrier frequencies (F, 2F, ... , nF).
7. Object simulator according to claim 5 or 6, wherein the majority of the carrier frequencies (F, 2F, ... , nF) cover at least the frequency bandwidth (42).
8. Object simulator according to one of claims 5 to 7, wherein the object simulator has a carrier signal generator (26) which has a power divider (72, 82), wherein the first and the second carrier signal (TS1, TS2) can be derived from a total carrier signal (TSG) via the power divider (72, 82).
9. Object simulator according to claim 8, wherein the carrier signal generator (26) has a respective frequency generation circuit (70.1, 70.2, ... , 70. n) for each carrier frequency (F, 2F, ... , nF), wherein the respective output signals of the respective frequency generation circuits (70.1, 70.2, ... , 70. n) can be combined via a power combiner (70) to form the total carrier signal (TSG).
10. Object simulator according to claim 8, wherein the carrier signal generator (26) comprises a first frequency generation circuit (80.1) and a second frequency generation circuit (80.2), wherein a first output signal (AG1) of the first frequency generation circuit (80.1) with a first frequency can be transformed to a second output signal (AG2) with several multiples of the first frequency by means of a harmonic generation circuit (80), wherein a third output signal (AG3) with a second frequency of the second frequency generation circuit (80.2) can be combined with the second output signal to form the total carrier signal (TSG).
11. Object simulator according to one of the preceding claims, wherein the first and the second carrier signal (TS1, TS2) are essentially the same.
12. Method for simulating an object for a sensor (14) for object detection, wherein the method comprises: Receiving a first signal (Sl) emitted by the sensor (14), wherein the first signal (Sl) is combined with a first carrier signal (TS1) to form a first working signal (Al) such that the first signal (Sl) is transformed over its frequency bandwidth (42) into a working band for the first working signal (Al), Changing the first work signal (Al) to a second work signal (A2) in the work band depending on at least one object to be simulated, Sending a second signal (S2), wherein the second working signal (A2) is combined with a second carrier signal (TS2) such that the second working signal (A2) is transformed from the working band into the frequency bandwidth (42) for the second signal (S2), wherein the second signal (S2) emulates a reflection of the first signal (Sl) at the at least one object to be simulated.
13. Method according to claim 12, wherein the first and second signals (S1, S2) each comprise a high-frequency signal in the microwave range.
14. Method according to claim 12 or 13, wherein the first and the second signal (S1, S2) are frequency modulated, in particular frequency modulated over a modulation bandwidth, wherein the modulation bandwidth is in particular at least twice as wide as the working band.
15. Method according to any one of claims 12 to 14, wherein the first carrier signal (TS1) has a plurality of carrier frequencies (F, 2F, ... , nF) and / or wherein the second carrier signal (TS2) has the plurality of carrier frequencies (F, 2F, ... , nF).
16. Method according to claim 15, wherein the majority of the carrier frequencies (F, 2F, ... , nF) cover at least the frequency bandwidth (42).
17. Method according to any one of claims 12 to 16, wherein the first and second carrier signals (TS1, TS2) are derived from a total carrier signal (TSG) via the power divider (72, 82).
18. Method according to any one of claims 12 to 17, wherein the first and the second carrier signal (TS1, TS2) are essentially the same.