Radar system and corresponding method

Abstract

The present invention relates to a radar system for environment detection, in particular for vehicles and / or transport devices and / or stationary applications, comprising: at least one transceiver unit for transmitting and receiving radar signals, configured to transmit a plurality of M physical angle-modulated signals, in particular chirps, from which a plurality of N virtual angle-modulated signals, in particular chirps, can be formed, each virtual signal comprising several, in particular M, sampling points distributed over the physical chirp.

Description

[Technical Field]

[0001] The present disclosure relates to radar systems, and more particularly to environmental detection and response methods. [Background technology]

[0002] Radar methods and corresponding systems for detecting an environment are known in principle. In [1] ("Concept and Implementation of a PLL-Controlled Interlaced Chirp Sequence Radar for Optimized Range-Doppler Measurements," IEEE Transactions on Microwave Theory and Techniques, Volume 64, Issue 10, October 2016, pages 3280-3289, DOI: 10.1109 / TMTT.2016.2599875), the concept of using chirp sequences to improve range and velocity measurements, respectively, by radar was proposed. However, this concept is considered relatively complex, especially in terms of technical implementation and the large number of correction steps proposed therein. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] "Concept and Implementation of a PLL-Controlled Interlaced Chirp Sequence Radar for Optimized Range-Doppler Measurements, IEEE Transactions on Microwave Theory and Techniques" (Volume: 64, Issue: 10, October 2016), Pages: 3280~3289, DOI: 10.1109 / TMTT.2016.2599875 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present disclosure is to propose a radar system for detecting an environment, in particular for vehicles and / or transport devices and / or for stationary applications, which allows relatively accurate radar measurements in a relatively simple manner. In particular, it should be possible to achieve unambiguous measurement results even over relatively large distances and / or at high speeds (relative radial velocities). This object is solved in particular by the features of claim 1. [Means for solving the problem]

[0005] In particular, the object is solved by a radar system for environmental detection (preferably for detection of distance and / or velocity, in particular relative radial velocity, of environmental or target objects and / or structures), in particular for vehicles (e.g., motor vehicles, in particular having capabilities for at least partially autonomous driving, or aircraft, in particular having capabilities for at least partially autonomous flying and / or unmanned, such as airplanes or helicopters) and / or for transport devices (e.g., for cranes) and / or for stationary applications, comprising: at least one transceiver unit for transmitting and receiving radar signals, configured to transmit several (in particular a plurality) N (in particular consecutive, possibly spaced apart in time) physical angle-modulated (in particular phase- and / or frequency-modulated) signals, in particular chirps, from which several (in particular a plurality) M virtual angle-modulated (in particular frequency- and / or phase-modulated) signals, in particular chirps (which may overlap in time with one another), can be or are formed, wherein each virtual signal comprises several, in particular M, sampling points distributed over a physical chirp.

[0006] The plurality N of physical signals may in particular be individual signals of a signal sequence, where the individual signals are, for example, spaced apart from one another (having regular intervals or equidistant spacing or at least partly - for all signals of a subgroup - or all having non-regular intervals or not being equidistantly spaced).

[0007] The shape and number of the respective signals may be predetermined (e.g., externally). It is also possible that the radar system comprises a unit (a calculation unit) configured to determine the appropriately adapted signals and signal shapes based on external specifications.

[0008] The idea of ​​the present disclosure is not only to actually transmit a (angle modulated) physical signal, but also to form or define at least one virtual signal from the sampling points of the physical signal or different physical signals.

[0009] A virtual signal may be composed of multiple sampling points, each associated with a respective physical signal, e.g., a first virtual signal may have a first sampling point (in time) of each of the physical signals, a second virtual signal may have a second sampling point of each of the physical signals, and so on (optionally).

[0010] Particularly preferably, the radar system comprises an evaluation unit (which may be formed partly or completely by the (first) transceiver unit, or partly or completely in addition to the transceiver unit), which determines at least one object parameter (particularly distance or a variable dependent and / or based thereon and / or velocity, in particular radial velocity or a variable dependent and / or based thereon) from radar signals received by the transceiver unit (and originally originating from the latter) reflected from objects in the environment (particularly downmixed), wherein the evaluation unit determines the respective object parameter (i.e., for example distance or radial velocity) taking into account both (some, in particular all) sampling points in the (respective) physical signal (or taking into account one or more (respective) physical signals themselves) and (some, in particular all) sampling points in the (respective) virtual signal (or one or more (respective) virtual signals themselves). Particularly preferably, the evaluation unit can determine the respective object parameter taking into account both slow-time frequencies as well as fast-time frequencies (each of which is described further below). The consideration (or employment or use) of the respective signal (or sampling points thereof) when determining the object parameters is to be understood in particular that the respective signal (or corresponding sampling points) is evaluated (in particular directly) during said determination, for example within a corresponding calculation operation. In particular, the mere definition of a virtual signal is not to be understood as a corresponding consideration (or use) of this signal in the determination of the object parameters.

[0011] A radar system according to the present disclosure is relatively efficient, in particular, relatively few computational steps are required to reliably determine or estimate object parameters.

[0012] The fast time should be understood in particular as the time that elapses between the respective physical signals. Alternatively or additionally, the fast time can be understood as the time that corresponds to the time interval between two (time-successive) sampling points of the respective physical signals.

[0013] The slow time should be understood in particular as the time that elapses between the respective virtual signals. Alternatively or additionally, the slow time can be understood as the time that corresponds to the time interval between two (time-successive) sampling points of the respective virtual signals.

[0014] Fast time frequencies are to be understood in particular as signal frequencies occurring during the transmission of physical signals.

[0015] The slow-time frequency is to be understood in particular as the signal frequency occurring during consideration of the respective virtual signal, preferably normalized to the slow-time sampling rate (so that it can alternatively be dimensionless).

[0016] An object parameter is to be understood in particular as a parameter characterizing the object (target or target structure) to be detected with respect to its position and / or orientation and / or movement (translation and / or rotation). Preferably, the object parameter is a single physical variable, i.e. not a parameter set.

[0017] According to a particularly preferred embodiment (particularly combinable with the above and / or the following embodiments), the virtual and / or physical signals are adjustable and / or adapted to system requirements. Preferably, the virtual and / or physical signals are adjustable to a predetermined resolution and / or accuracy and / or uniqueness range and / or a predetermined aiming stability for distance and / or velocity determination. According to this idea, the system (particularly the calculation and / or evaluation unit, for example the above-mentioned evaluation unit) is configured in such a way that certain specifications regarding the requirements to be achieved (e.g., a certain maximum speed that should be unambiguously measurable) are used or can be used in particular in determining or specifying the virtual and / or physical signals. Specifically, a corresponding virtual signal can first be defined based on the specified requirements, whereby (e.g., in a subsequent step) a corresponding physical signal is defined (and finally, then transmitted).

[0018] The physical and / or virtual signals can be ramped or shaped by linear signals modulated in frequency (or formed by one, in particular a single, ramp, respectively). The physical signal can be formed by an upward ramp. Alternatively or additionally, the virtual signal can be formed by an upward ramp. The physical signal can be formed by a downward ramp. Alternatively or additionally, the virtual signal can also be formed by a downward ramp. It is possible that the physical ramp is formed by an upward ramp and the virtual signal is formed by a downward ramp. It is also possible that the physical signal is formed by a downward ramp and the virtual signal is formed by an upward ramp. In particular, good results can be achieved if the slopes of the ramps of the physical and virtual signals are unequal (with respect to their signs).

[0019] The plurality of physical signals (in a sequence) may be at least 2, or at least 4, or at least 10, and / or at most 1000, or at most 100. The plurality of virtual signals (associated with a particular sequence of physical signals) may be at least 2, or at least 4, or at least 10, and / or at most 1000, or at most 100 signals. Each plurality of physical or virtual signals may also be referred to as a respective signal sequence. With such a signal sequence, a corresponding radar measurement is then preferably performed.

[0020] Preferably, the distance (d) or a variable dependent thereon (particularly the signal propagation time (τ)) or a variable based thereon is calculated based on the slow-time frequency (f) preferably taking into account (using) the following relationship or a similar relationship (e.g., having at least one different sign): slow ) and / or fast time frequency (f fast ) and / or the sweep rate of the virtual signal (μP) and / or the sweep rate of the physical signal (μR) and / or the signal duration of the virtual signal (T P ), especially the chirp duration, and / or the center RF transmit frequency (f c ) is determined taking into account:

[0021]

number

[0022]

number

[0023] and

[0024]

number

[0025] Preferably, velocity (v) or a variable dependent thereon and / or based thereon is calculated as a slow-time frequency (f) preferably taking into account (using) the following relationship or a similar relationship (e.g., having at least one different sign): slow ) and / or fast time frequency (f fast ) and / or the sweep rate of the virtual signal (μP) and / or the sweep rate of the physical signal (μR) and / or the signal duration of the virtual signal (T P ), especially the chirp duration, and / or the center RF transmit frequency (f c ) is determined taking into account:

[0026]

number

[0027]

number

[0028] and,

[0029]

number

[0030] Preferably, the transmission of the physical signals (signal sequences) is performed in such a way that the uniqueness range of the velocity measurements is independent of the length of the respective physical signals (e.g., different from [1], see equations (20) and (21)).

[0031] Particularly preferably, the system is designed as a MIMO radar system.

[0032] In an embodiment, the system may comprise at least two transmission channels, preferably configured for time division multiplexing, so that corresponding transmission signals form the same virtual signal (with corresponding time offsets) (i.e., each virtual signal may be defined by corresponding sampling points of the physical signals of two or more transmission channels).

[0033] Alternatively or additionally, the system may comprise at least two transmission channels, preferably configured for frequency division multiplexing, more preferably for fast-time frequency division multiplexing and / or slow-time frequency division multiplexing.

[0034] In an embodiment, at least two (particularly overlapping in time) groups of virtual signals may be defined, which are generated or defined by corresponding sequences of physical signals (particularly by time division multiplexing of the physical signals).

[0035] The distance between the individual physical signals may be equidistant or may not be equidistantly spaced (at least for a subgroup of the physical signals, and possibly for all physical signals).

[0036] Some virtual signals may overlap in time.

[0037] The above-mentioned object is further solved by a method for detecting an environment, in particular using the above-mentioned system and / or the system described below, in which at least some / plurality M physical (angle-modulated) signals, in particular chirps, are transmitted and at least some / plurality N virtual angle-modulated signals, in particular chirps, are defined, in which each virtual signal comprises some, in particular M, sampling points distributed over the physical chirps, in which at least one object parameter is determined from radar signals reflected, in particular downmixed, from objects in the environment and received by the transmitting / receiving unit, in which each object parameter is determined taking into account both (some) sampling points in the (respective) physical signal and (some) sampling points in the (respective) virtual signal.

[0038] Further method features arise in particular from the above and / or below description of the system's functionality and configuration, which may be implemented as corresponding method steps (whereby the corresponding evaluation and / or calculation steps may be performed by one of the above and / or below described units or by any other calculation and / or evaluation unit).

[0039] The aforementioned object is further solved by a vehicle (in particular a motor vehicle, e.g. an autonomous motor vehicle, in particular a passenger car and / or truck) and / or a stationary device, comprising the aforementioned system and / or configured to carry out the aforementioned method.

[0040] The above-mentioned object is further solved by a calculation and / or evaluation device, in particular configured for carrying out the above-mentioned method and / or having one / the above-mentioned features described for that evaluation device.

[0041] The aforementioned object is further solved in particular by a computer-readable storage medium, in particular for carrying out the aforementioned method and / or as a component of the aforementioned system and / or the aforementioned evaluation unit, comprising instructions which, when executed by a processor, cause at least one processor to implement the following steps:

[0042] Determining at least one object parameter from radar signals reflected by objects of the environment, in particular downmixed, and received by the transmitting / receiving unit, where each object parameter is determined taking into account both sampling points in the physical signal and sampling points in the virtual signal. Further steps according to embodiments result from the above and / or following description.

[0043] Example embodiments are described in more detail below with reference to the figures. [Brief explanation of the drawings]

[0044] [Figure 1] 1 shows a diagram of sampling in the horizontal frequency range. [Figure 2] FIG. 1 shows 2D Fourier spectra of different targets and limiting cases of distance and velocity. [Figure 3] 1 shows a diagram of TDM channels arranged on the same virtual ramp. [Figure 4] FIG. 1 illustrates fast-time FDM channels assigned to different fast-time frequencies, such as offsets. [Figure 5] FIG. 10 illustrates the alternating transmission of two groups of physical lamps. [Figure 6] 1 shows a simplified diagram of a system including an autonomous vehicle and a radar system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0045] In Figure 1, physical chirps (chirps may also be referred to as ramplets) are shown as corresponding sampling points (generated by the ADC) from which virtual ramps (also referred to as conceptual ramps) then result in a time-frequency plane. In particular, these are set in such a way that a subsequent method or algorithm for processing can reconstruct the physical range and / or (radial) velocity of a target, possibly with a 2D point spread function (and its side lobes identified). The sampling points collectively produce ADC samples.

[0046] ADC sampling (ADC = Anlag-Digital-Converter) within a chirp can be called fast-time sampling. Sampling points between chirps (on the same imaginary ramp) can be called slow-time sampling points.

[0047] The chirp and the virtual (conceptual) ramp may be implemented as an upward or downward ramp (in FIG. 1, a respective upward chirp is shown). In particular, it is possible for the physical signal (chirp) to be implemented as an upward ramp and the virtual signal to be implemented as a downward ramp (or vice versa). This can affect the sign of the slow-time or fast-time frequency of the target beat signal, as further explained or defined below. Below, for purposes of illustration (without limitation of generality), an embodiment with an upward ramp as the physical signal and an upward ramp as the virtual signal is described.

[0048] Figure 1 is shown as an example of this.

[0049] The characteristics of the physical signal (chirp) may depend on the requirements for uniqueness (in range and Doppler), target resolution and pointing stability. The input parameters are preferably: - Range resolution dR - unique range of distances R max - Unique Doppler Range max - Aim Stability T target .

[0050] The system parameters that may depend on the radar sensor are given by: - ADC sampling rate f s , sampling period t s - HF carrier frequency f0

[0051] From this, the modulation parameters of the physical lamp can be: - Virtual (conceptual) ramp distance (in Figure 1: "tau_P"):

[0052]

number

[0053] - Virtual Bandwidth:

[0054]

number

[0055] - Virtual Lamp Duration:

[0056]

number

[0057] - Virtual Ramp Sweep Speed:

[0058]

number

[0059] - Frequency increment:

[0060]

number

[0061] - Chirp duration

[0062]

number

[0063] - Number of chirps

[0064]

number

[0065] - Chirp Bandwidth

[0066]

number

[0067] - Chirp sweep rate

[0068]

number

[0069] A single target at a distance d and / or with a variable that depends on the round trip delay time τ, in particular a time-dependent distance d(t) and / or a (radial) velocity that depends on the round trip delay time τ(t) of the target, can produce the following beat signal (downmixed signal):

[0070]

number

[0071] where t specifies the time in the physical signal (fast time) and the index k of the physical signal in the virtual signal (slow time).

[0072] By transforming the beat signal into a 2D Fourier spectrum (e.g., without additional phase and / or frequency correction as in [1], see Figure 4), the target (normalized, see above) slow-time and fast-time frequencies are obtained.

[0073] This equation shows, in particular, that since target distance and target velocity are integrated at both fast-time and slow-time frequencies, the distance and velocity axes are not (necessarily) orthogonal to each other. For this reason, this 2D Fourier spectrum can also be designated as unaligned space.

[0074] The following affine transformation converts it between unaligned space and distance-velocity space:

[0075]

number

[0076]

number

[0077] and

[0078]

number

[0079] This may be done optionally after full MIMO processing and / or (especially subsequent) CFAR processing (CFAR = constant false alarm rate) and / or target detection, based on the (resulting) target list, and in particular not based on the entire frequency spectrum.

[0080] FIG. 2 shows a 2D Fourier spectrum of a received signal (beat signal) with multiple superimposed target echoes. From this spectrum, the range and velocity of the target can be determined according to Equation X, according to an embodiment. The 2D Fourier spectrum shows different targets and limiting cases of range and velocity. Specific limiting cases (e.g., highest range / highest velocity for uniqueness) are shown. "Slow time" / "Fast time" represent "slow-time frequency" / "fast-time frequency."

[0081] Figure 3 shows TDM (Time Division Multiplexed) MIMO channels arranged on the same virtual ramp. Essentially, in TDM, several transmitters are alternately switched. With this modulation waveform, it is preferable to scan the same virtual ramp for all TX channels.

[0082] In this case, the phase error correction for the kth TDM channel is a linear phase shift along the slow-time frequency (sampling frequency). H TDM,k (f slow ) = exp{-j2πkT R f slow}

[0083] In TDM methods, modulation parameters can be adjusted. This can be done by reducing the chirp duration of the physical signal and / or by increasing the virtual ramp duration, where in each case other parameters can be adjusted to maintain the required range of resolution and uniqueness. In particular, a distinction can be made between the physical ramp duration and the distance between two physical ramps in a TDM channel.

[0084] Figure 4 shows the different fast time frequency offsets f o 4 shows the fast-time FDM channels assigned to the transmitter. Due to the staggered frequency modulation of the transmitter in the chirp, the TX channels can be separated on the fast-time frequency axis as shown in FIG. 4. The beat signal is

[0085]

number

[0086] Expand to.

[0087] In such MIMO modulation, the offset modulator and the offset frequency f o The phase error caused by can be corrected by: H FTFDM, fo (f fast , f slow ) = exp{-j2πf o τ(f fast , f slow )} where τ(f fast , f slow ) is the slow-time frequency f slow and fast time frequency f fast The target round-trip time is

[0088] By staggering the frequency modulation of the transmitter along a virtual ramp, the TX channels can be separated on the slow-time frequency axis, similar to fast-time FDM.

[0089] To increase the resolution / sensitivity of the fast-time or slow-time frequency, additional groups of physical and / or virtual ramps can be interleaved and transmitted. This allows target phases from one group to be compared to each other and the phase shift or frequency to be estimated along an additional axis. This additional axis can be referred to as, for example, super-slow-time.

[0090] A corresponding example of alternating transmission of two groups of virtual ramps is shown in Figure 5. This can, for example, allow comparison of target phase from group to group. Furthermore, a new axis (ultra-slow time in addition to fast time and slow time) can be introduced.

[0091] In general, alternative methods to Fourier transforms, particularly compressed sensing, allow for splicing physical and / or virtual signals in a non-equidistant manner to perform reconstruction of the target's slow-time and / or fast-time frequencies, which can be advantageous for extending the resolution and / or uniqueness range of frequency estimation for certain target scenarios.

[0092] 6 illustrates a system 100 including an autonomous vehicle 110 and a radar measurement system (radar system) 10 according to an embodiment. The radar measurement system 10 includes a first radar unit 11 having at least one first radar antenna 111 (for transmitting and / or receiving corresponding radar signals), optionally a second radar unit 12 having at least one second radar antenna 121 (for transmitting and / or receiving corresponding radar signals), and an evaluation unit 13.

[0093] System 100 may have passenger input and / or output devices 120 (passenger interfaces), vehicle coordinator 130, and / or external input and / or output devices 140 (remote expert interfaces, e.g., for a control center). In an embodiment, external input and / or output devices 140 may enable a person and / or device outside (the vehicle) to set and / or modify settings on or in autonomous vehicle 110. This external person / device may be different from vehicle coordinator 130. Vehicle coordinator 130 may be a server.

[0094] System 100 enables autonomous vehicle 110 to have driving behavior that depends on parameters to be modified and / or set by a vehicle passenger (e.g., with passenger input and / or output devices 120) and / or other involved persons and / or devices (e.g., via vehicle coordinator 130 and / or external input and / or output devices 140). The driving behavior of an autonomous vehicle can be predetermined or modified by (explicit) input or feedback (e.g., by a passenger specifying a maximum speed or relative comfort level), by implicit input or feedback (e.g., passenger pulse), and / or by other suitable data and / or communication methods of driving behavior or preferences.

[0095] Autonomous vehicle 110 is preferably a fully autonomous motor vehicle (e.g., a car and / or truck), but may alternatively or additionally be a semi-autonomous or (other) fully autonomous vehicle, such as a watercraft (boat and / or ship), an (especially unmanned) aerial vehicle (plane and / or helicopter), a driverless motor vehicle (e.g., a car and / or truck), etc. Additionally or alternatively, an autonomous vehicle may be configured in such a way that it can switch between semi-autonomous and fully autonomous states, where the autonomous vehicle may have characteristics that can be associated with semi-autonomous vehicles as well as fully autonomous vehicles (depending on the state of the vehicle).

[0096] The autonomous vehicle 110 preferably includes an on-board computer 145 .

[0097] The evaluation unit 13 can be at least partially arranged in and / or on the vehicle 110, in particular integrated (at least partially) in the on-board computer 145 and / or integrated (at least partially) in a computing unit in addition to the on-board computer 145. Alternatively or additionally, the evaluation unit 13 can be integrated (at least partially) in the first and / or second radar units 11, 12. If the evaluation unit 13 is provided (at least partially) in addition to the on-board computer 145, the evaluation unit 13 can communicate with the on-board computer 145 such that data can be transmitted from the evaluation unit 13 to the on-board computer 145 and / or vice versa.

[0098] Additionally or alternatively, the evaluation unit 13 may be (at least partially) integrated with the passenger input and / or output devices 120, the vehicle coordinator 130, and / or the external input and / or output devices 140. In particular, in such cases, the radar measurement system may comprise the passenger input and / or output devices 120, the vehicle coordinator 130, and / or the external input and / or output devices 140.

[0099] In addition to at least one radar unit 11, 12, the autonomous vehicle 110 may be equipped with at least one other sensor device 150 (e.g., at least one computer vision system, at least one LIDAR, at least one speed sensor, at least one GPS, at least one camera, etc.).

[0100] The on-board computer 145 may be configured to control the autonomous vehicle 110. The on-board computer 145 may further process data from the at least one sensor device 150 and / or at least one other sensor, in particular a sensor provided or formed by the at least one radar unit 11, 12, and / or data from the evaluation unit 13 to determine the situation of the autonomous vehicle 110.

[0101] Based on the vehicle situation and / or programmed instructions, on-board computer 145 can preferably modify or control the driving behavior of autonomous vehicle 110. Evaluation unit 13 and / or on-board computer 145 are preferably (general) computing units adapted for I / O communication with vehicle control systems and at least one sensor system, but may additionally or alternatively be formed by any suitable computing unit (computer). On-board computer 145 and / or evaluation unit 13 may be connected to the Internet via a wireless connection. Alternatively or additionally, on-board computer 145 and / or evaluation unit 13 may be connected to any number of wireless or wired communication systems.

[0102] For example, any number of electrical circuits, particularly as part of the evaluation unit 13 and / or on-board computer 145, passenger input and / or output devices 120, vehicle coordinator 130, and / or external input and / or output devices 140, may be implemented on the circuit board of the corresponding electronic device. The circuit board may be a general circuit board (“circuit board”) that may have various components of an (internal) electronic system, connections of electronic devices, and other (peripheral) devices. Specifically, the circuit board may have electrical connections through which other components of the system may communicate electrically (electronically). Any suitable processor (e.g., digital signal processor, microprocessor, supporting chipset, computer-readable (non-volatile) memory elements, etc.) may be coupled to the circuit board (depending on appropriate processing requirements, computer design, etc.). Other components, e.g., external memory, additional sensors, controllers for audio-video playback, and peripheral devices, may be connected to the circuit board via cables, e.g., plug-in cards, or may be integrated into the board itself.

[0103] In various embodiments, the functionality described herein may be implemented in an emulated form (as software or firmware) with one or more configurable (e.g., programmable) elements arranged in a structure that enables that functionality. The software or firmware that provides the emulation may be provided in a (non-volatile) computer-readable storage medium that includes instructions that enable one or more processors to perform the corresponding functions (corresponding processes).

[0104] The foregoing description of the illustrated embodiments is not intended to be exhaustive or limiting with respect to the precise embodiments described. While specific implementations and examples of various embodiments or concepts have been described herein for illustrative purposes, deviating (equivalent) modifications will be apparent to those skilled in the art. These modifications may be made with reference to the foregoing detailed description or figures.

[0105] Various embodiments may include any suitable combination of the aforementioned embodiments, including alternative embodiments of the aforementioned embodiments in conjunctive form (e.g., corresponding "and" may be "and / or").

[0106] Additionally, some embodiments may include one or more objects (e.g., particularly non-volatile computer-readable media) having stored thereon instructions that, when executed, result in actions (methods) according to any one of the foregoing embodiments. Additionally, some embodiments may include devices or systems having any suitable means for performing the various operations of the foregoing embodiments.

[0107] In certain contexts, the embodiments discussed herein may be applicable to automotive systems, particularly autonomous vehicles (preferably autonomous automobiles), (safety-critical) industrial applications and / or industrial process control.

[0108] Furthermore, portions of the described radar systems or described radar measurement systems (or generally: wave-based measurement systems) may include electronic circuitry for performing the functions and methods described herein. In some cases, one or more portions of the respective systems may be provided by a processor configured specifically to perform the functions and method steps described herein. For example, the processor may include one or more application-specific components, or the processor may include programmable logic gates configured in a manner to perform the functions described herein.

[0109] It should be noted at this point that all parts or functions described above, individually and in any combination, particularly the details shown in the figures, are claimed as essential to the present disclosure, modifications of which will be well known to those skilled in the art.

[0110] It is further pointed out that the widest possible scope of protection is sought. In this respect, the disclosure contained in the claims may also be further clarified by features described in further features (even if these further features are not necessarily included). It is expressly pointed out that parentheses and the term "particularly" are intended to emphasize the optionality of a feature in the respective context (and are not intended to mean, on the contrary, that a feature without such identification will be regarded as mandatory in the corresponding context). [Explanation of symbols]

[0111] 10 Radar Measurement System 11 First Radar Unit 12 Second Radar Unit 13 Evaluation Units 100 systems 110 Autonomous Vehicles 111 First radar antenna 120 Passenger input and / or output devices 121 Second radar antenna 130 Vehicle Coordinator 140 External Input and / or Output Devices 145 Onboard Computer 150 Sensor Devices

Claims

1. A radar system for detecting an environment, comprising: at least one transceiver unit for transmitting and receiving radar signals, configured to transmit a plurality of M physical angle-modulated signals, or chirps, from which a plurality of N virtual angle-modulated signals, or chirps, can be formed, each virtual signal comprising a number of sampling points distributed over the physical chirp; at least one evaluation unit, which determines at least one object parameter from radar signals reflected from objects in the environment and received by the transceiver unit, and which determines the respective object parameter taking into account both several sampling points in each physical signal and several sampling points in each virtual signal; A radar system comprising:

2. 10. The system of claim 1, wherein the virtual and / or physical signals are adapted to system requirements and are adjustable to resolution, accuracy, and / or unique specifications in distance and / or velocity determination and / or to time-on-target specifications.

3. 3. The system according to claim 1, wherein the physical and / or virtual signals are modulated in frequency.

4. The distance (d) or the variable that depends thereon is a relationship [Equation 1] [Equation 2] and [Equation 3] Considering the slow time frequency (f slow ) and / or fast time frequency (f fast ) and / or the sweep rate (μ P ) and / or the sweep rate (μ R ) and / or the signal duration (T P ), and / or the center RF transmit frequency (f c 4. The system according to claim 1, wherein the determination is made taking into account:

5. 5. The system according to claim 1, wherein the system is designed as a MIMO radar system.

6. 6. A system according to any one of claims 1 to 5, wherein the system comprises at least two transmission channels configured for time division multiplexing, such that corresponding transmitted signals form the same virtual signal.

7. 7. The system according to claim 1, wherein the system comprises at least two transmission channels configured for frequency division multiplexing.

8. A system as claimed in any one of claims 1 to 7, wherein at least two groups of interleaved virtual and / or physical signals are defined.

9. 9. The system of claim 1, wherein the distances between the individual physical signals are equidistant, the distances being time differences.

10. 10. A system according to any one of claims 1 to 9, wherein the distances between the individual physical signals are not equidistantly spaced.

11. A method for detecting the environment using a system described in any one of claims 1 to 10, wherein at least one plurality M of physical angle-modulated signals, chirps, are transmitted, at least one plurality N of virtual angle-modulated signals, chirps, are defined, each virtual signal comprising several sampling points distributed across the physical chirps, and at least one object parameter is determined from radar signals reflected from objects in the environment and received by the transceiver unit, the each object parameter being determined taking into account both the sampling points in the physical signals and the sampling points in the virtual signals.

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