Radar device and control method thereof

Abstract

To detect an abnormal condition of a radar device with a simple method in a short time compared with a prior art.SOLUTION: In a radar device of the present invention, a radio receiving unit mixes a radio signal including a received chirp signal received and a radio signal including a transmitting chirp signal to detect a beat signal, performs band-pass filtering on the beat signal with a predetermined pass band width or performs low band-pass filtering at a predetermined low band cut-off frequency, executes two-dimensional FFT processing for a distance and a relative velocity on the filtered beat signal to calculate map information including a distance spectrum for a plurality of relative velocities, on the basis of, the map information, determines a frequency range of the distance and relative velocity to be a dead angle range of the radar device and calculates an average value of signal intensities of the received radio signals from the determined frequency range, and compares the calculated signal intensity with a threshold for abnormality detection to determine whether the radar device is in an abnormal condition.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radar device using, for example, a millimeter wave sensor and a control method thereof. [Background technology]

[0002] Conventionally, the time variation of the noise level has been monitored to detect an abnormal state of the radar device, such as interference with the radar device or a failure of the radar device.

[0003] For example, Patent Document 1 discloses a radar device having the following configuration for detecting and reporting ice, snow, and dirt on the radome without arranging sensors or the like in the radome of the radar device. This radar device is an FM radar device that transmits a frequency-swept FM signal, receives a reflected signal from the object, and detects the position of the object from the frequency of a beat signal obtained by mixing the reflected signal with a part of the transmitted signal, and is characterized by including a means for detecting dirt on the radome of the antenna based on the level of the low-frequency component of the beat signal.

[0004] Furthermore, Patent Document 2 discloses an on-vehicle radar device having the following configuration for detecting dirt without reducing the time resolution of target detection: This radar device detects objects around the vehicle and the road surface is included in the detection range, and is characterized in that a signal processing unit uses a beat frequency exceeding a second threshold value to detect the objects around the vehicle, and determines that dirt is present in the transmitting unit or receiving unit when the number of occurrences within a predetermined time of beat frequencies with reception levels exceeding a first threshold value in a predetermined frequency range is equal to or less than a predetermined value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-282229 [Patent Document 2] JP 2000-019242 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in these conventional radar devices, when calculating the reference noise level, it was necessary to perform the calculation in an ideal environment with little ambient reflection (for example, an anechoic chamber or an open outdoor space) in order to minimize the influence of multipath from stationary objects, the ground, etc. Also, since the noise level fluctuates due to the heat of the device, etc., a separate measure was required to constantly grasp the temperature of the device.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to solve the above problems and to provide a radar device and a control method thereof that can detect an abnormal state of the radar device in a simple manner and in a short time as compared with the prior art. [Means for solving the problem]

[0008] The radar device according to the present invention comprises: A radar device comprising: a radio transmitting unit that transmits a radio signal including a transmission chirp signal; and a radio receiving unit that receives a radio signal including the reflected reception chirp signal after the radio signal including the transmission chirp signal is reflected by a target, The wireless receiving unit includes: Detecting a beat signal by mixing the received radio signal including the received chirp signal with the radio signal including the transmitted chirp signal; band-pass filtering the beat signal with a predetermined passband width or low-pass filtering with a predetermined lower cutoff frequency; performing a two-dimensional FFT process of distance and relative velocity on the filtered beat signal to calculate map information including distance spectra for a plurality of relative velocities; determining a frequency range of distance and relative speed that is a blind spot range of the radar device based on the map information, and calculating an average value of the signal strength of the received wireless signal from the determined frequency range; The calculated signal strength is compared with a predetermined abnormality detection threshold to determine whether or not the radar device is in an abnormal state. Effect of the Invention

[0009] Therefore, according to the radar device etc. of the present invention, an abnormal state of the radar device can be detected in a simple manner and in a short time as compared with the prior art. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing an example of the configuration of a radar device 100 according to an embodiment. [Figure 2A] 2 is a graph showing a frequency change waveform of a chirp signal used in the radar device 100 of FIG. 1. [Figure 2B] 2 is a diagram showing gain frequency characteristics of the bandpass filters 24-1 to 24-N used in the radar device 100 of FIG. [Diagram 3] 1 is a plan view showing the positional relationship between a radar device 100 installed on a road 400 and a vehicle 310 traveling on a traffic lane 411. [Figure 4] 1 is a side view showing the positional relationship between a radar device 100 installed on a road 400 and a vehicle 310 traveling on a ground surface 300 of the road 400. FIG. [Diagram 5] FIG. 2 is a diagram showing a distance spectrum and an RV map (a map in which the distance and speed of a vehicle are mapped) calculated by the radar device 100 of FIG. [Figure 6] FIG. 2 is a diagram showing the relationship between the RV map calculated by the radar device 100 of FIG. 1 and power. [Figure 7] 4 is a flowchart showing pre-processing before reception executed by the radar device 100 of FIG. 1. [Figure 8] 2 is a flowchart showing a received signal process executed by the radar device 100 of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a radar device using, for example, an FCM system and a control method thereof according to an embodiment will be described with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment.

[0012] (Embodiment) 1 is a block diagram showing an example of the configuration of a radar device 100 according to an embodiment. The example of the configuration of the radar device 100 will be described below.

[0013] In order to solve the above-mentioned problems, a radar device 100 according to an embodiment of the present invention includes a pre-processing unit 4 and anomaly detection units 32-1 to 32-N (collectively denoted by the reference symbol 32). (A) The pre-processing unit 4 determines a frequency range (a frequency range indicating the relationship between distance and relative speed) that corresponds to the blind spots 51, 52 (meaning a range that cannot be detected by the radar device 100; see FIG. 6 ) of the radar device 100 based on information on the installation position of the radar device 100, calculates an average value of the signal strength based on the frequency range, and calculates an anomaly detection threshold based on the average value of the signal strength; (B) The abnormality detection unit 32 detects an “abnormal state” by performing two-dimensional FFT (Fast Fourier Transformation) processing on each beat signal for each received signal received by a plurality of antennas 21-1 to 21-N (collectively referred to as 21) and comparing the average value of the signal strength after the processing with the abnormality detection threshold value.

[0014] The radar device 100 according to the embodiment and the modified examples will be described below. Note that the embodiment and the modified examples described below are merely examples and are one embodiment of the present invention, and the present invention is not limited to these.

[0015] In FIG. 1, the radar device 100 estimates the distance and relative speed of a target using, for example, an FCM (Fast Chirp Modulation) method. In the FCM method, a transmission chirp signal, which is a repeat of multiple chirp signals whose frequencies change continuously, is wirelessly transmitted to the target to detect the distance and relative speed of each target present within a detection range. Specifically, the FCM method estimates the distance and relative speed of the target by performing two-dimensional fast Fourier transform processing (hereinafter referred to as two-dimensional FFT processing) on ​​a beat signal b(t) generated from a modulated signal that generates a chirp signal St and a received signal obtained by receiving a reflected wave of the transmission signal by the target. Note that the two-dimensional FFT processing includes two FFT processes, a distance FFT process and a speed FFT process.

[0016] Fig. 2A is a graph showing a frequency change waveform diagram of a chirp signal used in the radar device 100 of Fig. 1. As shown in Fig. 2A, the chirp signal rises over time with a chirp gradient Δf [Hz / s].

[0017] The maximum detection distance R of the radar device 100 when using the chirp signal of FIG. max and maximum detection speed V max As is well known, it is expressed by the following formula:

[0018]

number

[0019]

number

[0020] Here, fs is the sampling rate, c is the speed of light (which is a fixed value of 299792458), S is the slope of the chirp signal, B is the occupied bandwidth of the radar signal, λ is the wavelength of the radar signal, and Tc is the period of the chirp signal (=occupied bandwidth B / slope of the chirp signal S).

[0021] 2B is a diagram showing the gain-frequency characteristics of the bandpass filters 24-1 to 24-N (collectively denoted by the reference symbol 24) used in the radar device 100 of FIG. 1. As shown in FIG. 2B, the gain of the bandpass filter 24 has a frequency characteristic in which, for example, it rises from a gain Gmin, has a maximum gain Gmax at a normalized lower limit frequency fmin of the passband, and after maintaining the maximum gain Gmax within the passband, it drops from the normalized upper limit frequency fmax to a predetermined frequency fm. That is, the bandpass filter 24 has a predetermined passband width that passes the main component of the beat signal b(t). Note that, instead of each bandpass filter 24, a lowpass filter having a predetermined lower cutoff frequency and passing the main component of the beat signal b(t) may be used.

[0022] 1, the radar device 100 includes a radio transmission unit 1, a radio reception unit 2, and a signal processing unit 3. Here, the radio transmission unit 1 includes a transmission control unit 10, a modulated signal generation unit 11, an oscillator 12, a power amplifier 13, and a transmission antenna 14. The radio reception unit 2 includes one or more N reception antennas 21-1 to 21-N (hereinafter collectively referred to as 21), a plurality of N low noise amplifiers 22-1 to 22-N (hereinafter collectively referred to as 22), a plurality of N mixers 23-1 to 23-N (hereinafter collectively referred to as 23), a plurality of N band pass filters (BPFs) 24, and a plurality of N AD converters (ADCs) 25-1 to 25-N (hereinafter collectively referred to as 25).

[0023] Furthermore, the signal processing unit 3 includes a pre-processing unit 4, a plurality of N distance and speed estimation units 31-1 to 31-N (hereinafter collectively referred to as 31), a plurality of N abnormality detection units 32-1 to 32-N (hereinafter collectively referred to as 32), an arrival angle estimation unit 33, and a display unit 34. Here, each of the abnormality detection units 32 includes anomaly detection threshold memory 321m, 322m, 323m, ..., 32Nm that stores anomaly detection thresholds.

[0024] The pre-processing unit 4 also includes an information input unit 41, a blind spot range calculation unit 42, and an anomaly detection threshold calculation unit 43. The pre-processing unit 4 executes pre-processing shown in FIG. 5, which will be described later, before transmitting the radar signal. Here, the user inputs information on the installation position of the radar device 100 using the information input unit 41. Next, the blind spot range calculation unit 42 determines a frequency range (a frequency range indicating the relationship between distance and relative speed) that becomes the blind spot ranges 51, 52 (see FIG. 6) based on the input information on the installation position of the radar device 100. Furthermore, the anomaly detection threshold calculation unit 43 calculates an average value of the signal strength based on the determined frequency range, calculates an anomaly detection threshold based on the average value of the signal strength, and stores and memorizes the calculated threshold in the anomaly detection threshold memories 321m to 32Nm in each anomaly detection unit 32.

[0025] The transmission control unit 10 of the wireless transmission unit 1 transmits a predetermined transmission interval T n The oscillator 12 generates a transmission interval signal Si having the transmission interval Tn and outputs it to the modulation signal generator 11. The modulation signal generator 11 generates a modulation signal (chirp signal) whose frequency changes in a triangular wave shape, such as a sawtooth wave shape as shown in FIG. 2A, and outputs it to the oscillator 12. The oscillator 12 generates a radio signal St including a transmission chirp signal having the transmission interval Tn in accordance with the modulation signal, and outputs this to the transmission antenna 14 via the power amplifier 13, and the radio signal including the transmission chirp signal St is radiated from the transmission antenna 14 towards the target (object). The radio signal St including the transmission chirp signal from the oscillator 12 is also distributed to a mixer 23 of the radio receiving unit 2.

[0026] In the radio receiving unit 2, the multiple N receiving antennas 21 constituting the array antenna receive radio signals St including a transmission chirp signal, which is a wave reflected from a target that is a reflector, as radio signals Sr including a reception chirp signal, and output the radio signals Sr to a mixer 23 via a low-noise amplifier 22. Each mixer 23 mixes the radio signal Sr including the reception chirp signal contained in the radio signal from each low-noise amplifier 22 with the radio signal St including the transmission chirp signal from the oscillator 12, and outputs the result to each band-pass filter 24. Each band-pass filter 24 performs filtering with the band-pass characteristics of FIG. 2B described above, thereby detecting a beat signal b(t) having a beat frequency and outputting the result to each AD converter 25. Each AD converter 25 AD-converts the input beat signal b(t) into a digital beat signal and outputs the result to each distance and speed estimation unit 31 of the signal processing unit 3.

[0027] 1 is, for example, equal to or greater than 1. In this embodiment, distance estimation or speed estimation is possible with one receiving antenna 21, but when estimating the arrival angle, two or more receiving antennas 21 are required.

[0028] The signal processing unit 30 is configured by a microcomputer including, for example, a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), input / output ports, etc., and controls the radar device 100 as a whole.

[0029] Each distance and velocity estimation unit 31 performs known two-dimensional FFT processing (distance FFT processing and velocity FFT processing) on ​​the beat signal b(t) output from each AD converter 25, calculates the distance and relative velocity of the target based on the results of the two-dimensional FFT processing, and outputs them to the anomaly detection unit 32.

[0030] Each anomaly detection unit 32 performs two-dimensional FFT processing on each beat signal b(t) for each reception signal received by a plurality of antennas 21-1 to 21-N (collectively denoted by the reference symbol 21), and compares the average value of the signal strength after processing with the anomaly detection threshold stored in anomaly detection threshold memories 321m to 32Nm to detect whether or not there is an "abnormal state," and outputs the detection result to be displayed on the display unit 34, and also outputs the detection result to the arrival angle estimation unit 33. Details of the anomaly detection processing in the anomaly detection unit 32 will be described later.

[0031] The arrival angle estimation unit 33 estimates the arrival angle of the target by a predetermined known arrival angle calculation process based on the radio signal Sr including multiple received chirp signals or the beat signal b(t) generated based on the same. For example, each arrival angle estimation unit 33 estimates the arrival angle of the target based on the difference in phase of the peak of the same distance bin of each of the frequency spectra of the multiple beat signals b(t) based on the multiple received signals received by the receiving antenna 21. If it is detected that multiple targets (reflectors) exist in the same distance bin due to the difference in the phase of the peak of the same distance bin, angle estimation is performed for each of the multiple targets. The angle estimation in the arrival angle estimation unit 33 is performed using a known estimation method such as ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), DBF (Digital Beam Forming), or MUSIC (Multiple Signal Classification).

[0032] The arrival angle estimation unit 33 outputs information relating to the distance and relative speed to the target estimated by each distance and speed estimation unit 31, in addition to the calculated arrival angle of the radio signal reflected by the target, to the other control device 200. In Fig. 1, the other control device 200 is another radar device or a control device that comprehensively controls the radar device 100 and the other radar devices.

[0033] Next, the abnormality detection process performed by the abnormality detection unit 32 will be described in detail below.

[0034] Fig. 3 is a plan view showing the positional relationship between the radar device 100 installed on a road 400 and a vehicle 310 traveling on a traffic lane 411. Fig. 4 is a side view showing the positional relationship between the radar device 100 installed on the road 400 and a vehicle 310 traveling on the ground 300 of the road 400.

[0035] 3, a road 400 has a driving lane 411 between a center line 401 and a shoulder strip 402, and a driving lane 423 between the center line 401 and a shoulder strip 403. A vehicle 310 travels on the driving lane 411 at a speed V, and the radar device 100 is installed on the driving lane 412 near the shoulder strip 403. A radar signal from the radar device 100 is reflected by a reflection point Rp on the upper part of the windshield. Furthermore, in FIG. 4, the radar device 100 is installed at a height H from the ground 300 of the road 400, and the vehicle 310 has a vehicle height h.

[0036] 3, the installation coordinates of the radar device 100 are [0,0], and the reflection point coordinates on the vehicle 310 are [x,y]. In addition, in the vertical plane of FIG. 4, the installation coordinates of the radar device 100 are [0,0], and the reflection point coordinates on the vehicle 310 are [x,Hy]. At this time, the relative velocity V R (φ, θ) is expressed by the following equation.

[0037]

number

[0038] Here, the horizontal angle φ and the vertical angle θ are expressed by the following equations.

[0039]

number

[0040]

number

[0041] Fig. 5 is a diagram showing a distance spectrum and an RV map (a map in which the distance and speed of a vehicle are mapped) calculated by the radar device 100 of Fig. 1, and Fig. 6 is a diagram showing the relationship between the RV map and power calculated by the radar device 100 of Fig. 1. Here, the abnormality detection process according to this embodiment is characterized in that blind spot ranges 51 and 52 in Fig. 6 are set for specific distance and speed bins.

[0042] Each distance and velocity estimation unit 31 performs known two-dimensional FFT processing (distance FFT processing and velocity FFT processing) on ​​the beat signal b(t) output from each AD converter 25, and calculates the distance and relative velocity of the target based on the results of the two-dimensional FFT processing. Here, the calculated distance and relative velocity of the target are calculated by calculating a spectrum for the distance bin for each velocity bin number, as shown in Fig. 5, and the calculated multiple spectra are calculated as an RV map (a map of distance R and velocity V).

[0043] The blind spot ranges 51 and 52 are calculated by the blind spot range calculation unit 42, are illustrated in the RV map, and are defined as follows: (A) Blind spot range 51: range of distance bin numbers 1 to m and speed bin numbers 1 to n; (B) Blind spot range 52: range of distance bin numbers 1 to m and speed bins (Nn-1) to N.

[0044] Here, the parameters used in the abnormality detection process are as follows:

[0045] (1) Maximum detection distance R max [m] (see formula above) (2) Maximum detection speed ±V max [km / h] (see formula above) (3) Number of distance bins M[bin] (4) Number of speed bins N[bin] (5) Installation height H [m] of the radar device 100 (see FIG. 4) (6) Height limit for large vehicles lim [m] (for example, 3.8 to 4.1 m) (7) Margin distance bin m[bin] (e.g., 5 to 10)

[0046] (8) Margin distance R margin [m] is expressed by the following formula.

[0047]

number

[0048] However, R margin >Hh (see Figure 4).

[0049] (9) The margin speed bin n [bin] (where n is an integer) is expressed by the following equation.

[0050]

number

[0051]

number

[0052] (10) Margin Speed ​​V margin [km / h] is expressed by the following formula.

[0053]

number

[0054] (11) Maximum detection distance R max is represented as described above with reference to FIG. 2A.

[0055] (12) Maximum detection speed ±V max is represented as described above with reference to FIG. 2A.

[0056] Next, the threshold value used for detecting an anomaly will be described below.

[0057] (1) Average signal strength in blind spots 51 and 52

number

[0058]

number

[0059] where r is the distance index, v is the velocity index, and |S(v;r) is the amplitude spectrum under normal conditions.

[0060] (2) Threshold for detecting anomalies S TH is expressed by the following equation.

[0061]

number

[0062] Here, α is a value of about 3 to 5.

[0063] The results of abnormality detection based on threshold value judgment for each frame will be described below.

[0064] The result of abnormality detection based on threshold judgment for each frame is expressed by the following equation.

[0065]

number

[0066] Therefore, the average signal strength in the blind spots 51 and 52

number

[0067]

number

[0068] where t is the frame index and |Q(t;v;r)| is the amplitude spectrum to be evaluated.

[0069] FIG. 7 is a flowchart showing pre-processing before reception executed by the pre-processing unit 4 of the radar device 100 of FIG.

[0070] 7, the user inputs information on the installation location of the radar device 100 using the information input unit 41, and in step S2, the blind spot range calculation unit 42 calculates blind spot ranges 51, 52 (frequency ranges indicating specific distances and speeds) based on the input information on the installation location of the radar device 100. Next, in step S3, the abnormality detection threshold calculation unit 43 calculates the average value of the signal strength of the blind spot ranges 51, 52 based on the calculated blind spot ranges 51, 52.

number

number

[0071] FIG. 8 is a flowchart showing the received signal processing executed by the radar device 100 of FIG.

[0072] 8, a radio signal including a chirp signal is transmitted from radio transmitting unit 1, and received by radio receiving unit 2. Next, in step S12, the transmitted chirp signal and the received chirp signal are mixed, band-pass filtered by band-pass filter 24, and AD converted by AD converter 25 to generate each beat signal. Furthermore, in step S13, distance and velocity estimation unit 31 performs two-dimensional FFT processing of distance and Doppler velocity on each beat signal.

[0073] Next, in step S14, the abnormality detection unit 32 calculates the average value of the signal strength in the blind spots 51 and 52.

number

[0074] The present inventors performed a simulation on the radar device 100 of Fig. 1. The results will be described in the following Examples 1 and 2. EXAMPLES

[0075] In Example 1, the parameters and calculation results of the example in which an automobile was used as the assumed target are shown in Table 1 below.

[0076] [Table 1] ---------------------------------------------------------------------------------- Maximum detection distance R max =200[m] Maximum detection speed ±V max =70[km / h] Number of distance bins M = 512 [bin] Number of speed bins N=512[bin] Radar equipment installation height H=6m (Assuming installation near traffic lights, traffic signs, and road guide signs) Height limit for large vehicles lim =4.1[m] (H lim =1.9m) Margin distance bin number m=10[bin] Margin distance R margin =3.9[m] Margin speed bin number n=32[bin] Margin Speed ​​V margin = ±8.75 [km / h] (-70~-61.25, 61.25~70[km / h]) Target vehicle's driving position x=5.00m Target vehicle's driving position y=1.75m Target vehicle height h=2.30m (Hh=3.70m) (An example of a particularly large passenger car is the Toyota (Figures for the Hiace Wagon GrandCabin (registered trademark) are used as a reference example) Horizontal angle φ=19.29 degrees Vertical angle θ=36.50 degrees Vehicle speed V = 60.00 [km / h] The relative velocity V from the radar at this time R (φ,θ)=45.52[km / h] ----------------------------------------------------------------------------------

[0077] As is clear from Table 1, it is possible to sufficiently separate the frequency range used for the anomaly detection range and the distance / velocity of the target object. EXAMPLES

[0078] In Example 2, the parameters and calculation results for an example in which a pedestrian or a bicycle is the assumed target are shown in Table 2 below.

[0079] [Table 2] ---------------------------------------------------------------------------------- Maximum detection distance R max =100[m] Maximum detection speed ±V max =40[km / h] Number of distance bins M = 512 [bin] Number of speed bins N=512[bin] The height of the radar device is H = 3m (assuming it is installed near a street light, etc.) Maximum height h of pedestrians and bicycles lim =2[m](Hh lim =1m) Margin distance bin number m=10[bin] Margin distance R margin =1.95[m] Margin speed bin number n=36[bin] Margin Speed ​​V margin = ±5.625 [km / h] (-40~-34.375, 34.375~40[km / h]) Position of object x=1m Object position y=0m Height of object h=1.7m (Hh=1.30m) Horizontal angle φ=0 degrees Vertical angle θ=52.43 degrees Object speed V = 40.00 [km / h] Relative velocity from the radar V R (φ,θ)=24.39[km / h] (Note) The subject was assumed to be "bicycles (especially road bikes)." ----------------------------------------------------------------------------------

[0080] As is clear from Table 2, it is possible to sufficiently separate the frequency range used for the anomaly detection range and the distance / velocity of the target object.

[0081] As described above, according to this embodiment, it is possible to detect an abnormal state of the radar device, such as interference with the radar device or a failure of the radar device, in a simpler manner and in a shorter time than in the conventional technology.

[0082] The radar device 100 according to this embodiment, unlike an in-vehicle radar, effectively utilizes the installation condition of an infrastructure radar device (particularly for road monitoring applications) in which a target, particularly a moving object, is not necessarily located directly in front of the radar's line of sight. This means that the closer the target is to the radar, the steeper the angle at which it is located, and the greater the change in relative speed with respect to the radar's line of sight.

[0083] The radar device 100 according to the present embodiment can be applied to an abnormal operation detection function in an infrastructure radar device (FCM modulation type, FMCW modulation type, pulse compression modulation type) equipped with a millimeter wave sensor, for example. In particular, it can be used as a technical means for realizing abnormality detection in a millimeter wave radar device for road monitoring, and as an application, the radar device can be attached to a traffic light or a traffic sign, and the position and speed of a vehicle can be detected and a traffic counter can be performed to ease congestion. Here, when a user obtains distance, relative speed, and direction information of a reflecting object, the user can determine whether the information is normal or abnormal, which leads to a reduction in the occurrence of traffic accidents.

[0084] Furthermore, the radar device 100 according to this embodiment can increase the processing speed and determine whether or not a constant false alarm rate (CFAR) is required as pre-processing for detecting targets, thereby reducing the number of CFAR processes. In other words, the radar device 100 has a unique effect that CFAR is not required for all distance and relative velocity bins, i.e., two-dimensional CFAR is not required.

[0085] (Modification) In the above embodiment, the transmission chirp signal has been described as a signal whose frequency increases continuously (i.e., an up-chirp), but it may be a chirp signal whose frequency decreases continuously (i.e., a down-chirp), or a combination thereof.

[0086] In the above embodiment, a radar device using the FCM method has been described, but the present invention is not limited to this, and can be applied to a radar device using the FMCW modulation method or the pulse compression modulation method.

[0087] In the above embodiment, the position and relative velocity of the target are estimated, but the present invention is not limited to this, and may be configured to estimate only the relative velocity of the target.

[0088] Further advantages and modifications to the above embodiments may be readily derived by those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Thus, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof.

[0089] (Differences between this embodiment and Patent Document 1) In this embodiment, two-dimensional FFT processing (distance FFT processing and velocity FFT processing) is performed on the beat signal, and the frequency range (distance and relative velocity) that is the blind spot range is determined from the installation position information. Next, the average value of the signal strength is calculated from the frequency range that is the blind spot, and anomaly detection is performed by threshold judgment.

[0090] In contrast, in Patent Document 1, distance FFT processing is performed on the beat signal, the average value of the signal strength in the short distance range is calculated, and anomalies (dirt on the radome) are detected by threshold judgment. Next, the distance and direction to the target are calculated and output from the results of angle FFT processing.

[0091] (Differences between this embodiment and Patent Document 2) In this embodiment, two-dimensional FFT processing (distance FFT processing and velocity FFT processing) is performed on the beat signal, and the frequency range (distance and relative velocity) that is the blind spot range is determined from the installation position information. Next, the average value of the signal strength is calculated from the frequency range that is the blind spot, and anomaly detection is performed by threshold judgment.

[0092] In contrast, in Patent Document 1, the beat signal is subjected to two-dimensional FFT processing (distance The system performs FFT processing (FFT and speed FFT processing) to determine the frequency (distance) range of the road surface reflection signal from the vehicle speed and road surface reflection distance. Next, thresholds are used to determine the signal strength and duration of the road surface reflection and detect abnormalities (antenna dirt). Then, the system calculates and outputs the distance to the target, relative speed, and direction from the results of angle FFT processing. [Industrial Applicability]

[0093] As described above in detail, the radar device and the control method thereof according to the present invention make it possible to detect an abnormal state of the radar device in a simpler manner and in a shorter time than in the prior art.

[0094] The radar device according to the present invention can be applied to technical means for implementing interference countermeasures, for example, in millimeter-wave radar for road monitoring. Applications include attaching the radar device to traffic signals and traffic signs to detect the position and speed of vehicles and perform traffic countermeasures to ease congestion. The present invention can also be applied to the interference detection function of radar devices (FCM modulation type, FMCW modulation type, pulse compression modulation type) equipped with millimeter-wave sensors, and can be applied to long-range radars for weather, marine, and aircraft applications, for example. [Explanation of symbols]

[0095] 1 Radio transmitter 2. Radio receiver 3. Signal Processing Section 4 Preprocessing section 10 Transmission control section 11 Modulation signal generator 12 Oscillators 13 Power Amplifier 14 Transmitting Antenna 21,21-1~21-N Receiving antenna 22,22-1~22-N Low noise amplifier 23,23-1~23-N Mixer 24,24-1~24-N Bandpass Filter (BPF) 25,25-1~25-N Analog-to-Digital Converter (ADC) 31, 31-1 to 31-N Distance and speed estimation section 32, 32-1 to 32-N Abnormality detection section 321m, 322m, 323m~32Nm Threshold memory for abnormality detection 33 Arrival angle estimator 34 Display section 41 Information input section 42 Blind Spot Calculation Unit 43 Abnormality detection threshold calculation unit 51,52 Blind Spot Range 100 Radar Equipment 200 Other control devices 300 ground 310 Vehicles 400 road 401 Chuo Line 402,403 Roadside strip 411,412 travel lanes

Claims

1. A radar device comprising: a radio transmitting unit that transmits a radio signal including a transmission chirp signal; and a radio receiving unit that receives a radio signal including the reflected reception chirp signal after the radio signal including the transmission chirp signal is reflected by a target, The wireless receiving unit includes: Calculating a blind spot range of the radar device based on installation information of the radar device; Detecting a beat signal by mixing the received radio signal including the received chirp signal with the radio signal including the transmitted chirp signal; band-pass filtering the beat signal with a predetermined passband width or low-pass filtering with a predetermined lower cutoff frequency; performing a two-dimensional FFT process of distance and relative velocity on the filtered beat signal to calculate map information including distance spectra for a plurality of relative velocities; determining a frequency range of distance and relative speed that is a blind spot range of the radar device based on the map information, and calculating an average value of the signal strength of the received wireless signal from the determined frequency range; The calculated signal strength is compared with a predetermined abnormality detection threshold to determine whether the radar device is in an abnormal state. Radar equipment.

2. the wireless receiving unit calculates an average value of signal strength in the blind spot range based on the calculated blind spot range of the radar device, and calculates an anomaly detection threshold value based on the calculated average value of signal strength. The radar device according to claim 1 .

3. the wireless receiving unit receives a plurality of wireless signals each including a received chirp signal when the radar device is not in an abnormal state, and estimates an arrival angle of the target based on the received plurality of wireless signals.

3. A radar device according to claim 1 or 2.

4. The transmit chirp signal has a continuously varying frequency. The radar device according to any one of claims 1 to 3.

5. A method for controlling a radar device including a radio transmitting unit that transmits a radio signal including a transmitted chirp signal, and a radio receiving unit that receives a radio signal including a received chirp signal after the radio signal including the transmitted chirp signal is reflected by a target, comprising: The wireless receiving unit, calculating a blind spot range of the radar device based on installation information of the radar device; detecting a beat signal by mixing the received radio signal including the received chirp signal with the radio signal including the transmitted chirp signal; band-pass filtering the beat signal with a predetermined passband width or low-pass filtering with a predetermined lower cutoff frequency; performing a two-dimensional FFT process of distance and relative velocity on the filtered beat signal to calculate map information including distance spectra for a plurality of relative velocities; determining a frequency range of distance and relative speed that is a blind spot range of the radar device based on the map information, and calculating an average value of the signal strength of the received wireless signal from the determined frequency range; determining whether the radar device is in an abnormal state by comparing the calculated signal strength with a predetermined abnormality detection threshold; Further comprising: A method for controlling a radar device.

6. the wireless receiving unit calculates an average value of signal strength in the blind spot range based on the calculated blind spot range of the radar device, and calculates an abnormality detection threshold value based on the calculated average value of signal strength. A method for controlling a radar device according to claim 5.

7. and further comprising a step of receiving, by the wireless receiving unit, a plurality of wireless signals each including a received chirp signal when the radar device is not in an abnormal state, and estimating an arrival angle of the target based on the plurality of received wireless signals.

7. A method for controlling a radar device according to claim 5 or 6.

8. The transmit chirp signal has a continuously varying frequency. A method for controlling a radar device according to any one of claims 5 to 7.

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