JP7317739B2 - Radar device, object detection method and program - Google Patents

Description

The present disclosure relates to radar devices, object detection methods, and programs.

As a method of analyzing the signal received by the radar device, the information of the received signal obtained by one radar measurement is regarded as information for one frame, and the difference is calculated and analyzed from the information between a plurality of frames (for example, The method described in Patent Document 1) and the method of calculating and analyzing an average value (for example, the method described in Patent Document 2).

U.S. Patent Application Publication No. 2018/0267164 JP 2019-74527 A

However, with these methods, it takes a lot of time to analyze information between a plurality of frames received by the radar device.

An object of the present invention is to provide a radar device, an object detection method, and a program capable of efficiently processing information analysis between a plurality of received frames in a short time.

In order to solve the above-described problems and achieve the object, a radar device according to the present disclosure provides a first transmission signal in a first frequency band and a second frequency band in a second frequency band having a frequency band different from the first frequency band. 2 transmission signals and signals in at least two or more frequency bands; and the first and second transmission signals transmitted by the transmission unit and reflected by one or more objects. , a receiver for receiving as a first received signal and a second received signal, respectively; and a distance calculator for calculating distance information to one or more of the objects based on the first received signal and the second received signal. , a speed calculator for calculating relative speed information with respect to one or more of the objects based on the first received signal and the second received signal; and amplitude information corresponding to the distance information or the relative speed information. a selection unit that selects amplitude information corresponding to a specific physical quantity from the first amplitude information as first amplitude information; the first amplitude information; A recording unit for recording, a first target determination unit for determining a target based on the first amplitude information recorded in the recording unit, and the second amplitude information recorded in the recording unit and a second target determination unit that determines the target based on the first amplitude information obtained from at least the first received signal and the second received signal are combined, and the target is determined based on the combined first amplitude information.

In the radar device according to the present disclosure, in the above disclosure, the recording unit includes a first recording unit that records the first amplitude information and a second recording unit that records the second amplitude information, The first recording unit updates the newly selected first amplitude information when the frequency band of the first amplitude information already recorded is the same as the frequency band of the newly selected first amplitude information. It is configured to record by

In the radar device according to the present disclosure, in the above disclosure, the recording unit includes a first recording unit that records the first amplitude information and a second recording unit that records the second amplitude information, The first recording unit is configured to record respective first amplitude information when the frequency band of the previously recorded first amplitude information is different from the frequency band of the newly selected first amplitude information.

In the radar device according to the present disclosure, in the above disclosure, according to a predetermined phase angle corresponding to at least one predetermined distance and the first frequency band or the second frequency band, a rotation processing unit that rotates on an IQ plane at least one of the first amplitude information obtained from the transmission signal and the first amplitude information obtained from the transmission signal in the second frequency band; and the rotation processing. Arithmetic processing for adding or subtracting the first amplitude information obtained from the transmission signal in the first frequency band, at least one of which is rotated by the unit, and the first amplitude information obtained from the transmission signal in the second frequency band. and the first target determination unit is configured to determine a target based on the result processed by the arithmetic processing unit.

In the radar device according to the present disclosure, in the above disclosure, the rotation processing unit transmits the relative velocity information, which is the specific physical quantity, and the first transmission signal when performing the processing of rotating on the IQ plane. The amount of rotation is corrected based on the time from when the second transmission signal is transmitted.

In the radar device according to the present disclosure, in the above disclosure, the predetermined distance is selected from at least one or more targets obtained by performing target determination by the second target determination unit. distance selected to correspond to the distance of one target.

The radar device according to the present disclosure is the radar device mounted on the vehicle in the above disclosure, wherein the predetermined distance is a distance selected to correspond to the distance from the radar device to the bumper of the vehicle. is.

In the radar device according to the present disclosure, in the above disclosure, the rotation processing unit converts a speed of n [m/s] (n is a number of 0 or more) relative to one or more targets to the specific This is a configuration for processing as a physical quantity.

In the radar device according to the present disclosure, in the above disclosure, the rotation processing unit, in the first amplitude information selected by the selection unit, rotates the first amplitude information with respect to the speed direction for each distance from one or more objects. The configuration is such that the speed of at least one target is selected from among at least one or more targets determined by one target determination unit, and the selected speed is processed as the specific physical quantity.

In the radar apparatus according to the present disclosure, in the above disclosure, based on the first amplitude information obtained from the first received signal and the first amplitude information obtained from the second received signal, A configuration comprising an amplitude difference acquisition unit that acquires an amplitude difference in a range, and an interference detection unit that detects occurrence of interference when the amplitude difference acquired by the amplitude difference acquisition unit is equal to or greater than a predetermined threshold. be.

In the radar apparatus according to the present disclosure, in the above disclosure, the interference detection section is configured to discard the first amplitude information recorded in the recording section when the occurrence of interference is detected.

In the radar device according to the present disclosure, in the above disclosure, the first amplitude information obtained from the first received signal and the first amplitude information obtained from the second received signal are averaged or integrated A calculation processing unit for calculating a value is provided, and the first target determination unit performs target determination using the amplitude values averaged or integrated in the calculation processing unit.

In order to solve the above-described problems and achieve the object, the object detection method according to the present disclosure includes a first transmission signal in a first frequency band and a second frequency band having a frequency band different from the first frequency band. a transmitting step of transmitting signals in at least two or more frequency bands with a second transmission signal of; and the first transmission signal and the second transmission transmitted by the transmitting step and reflected by one or more objects a receiving step of receiving signals as a first received signal and a second received signal, respectively; and a distance calculation of calculating distance information to one or more of the objects based on the first received signal and the second received signal. a speed calculation step of calculating relative speed information with respect to one or more of the objects based on the first received signal and the second received signal; and amplitude information corresponding to the distance information or the relative speed information. A selection step of selecting amplitude information corresponding to a specific physical quantity as first amplitude information from among; said first amplitude information; and second amplitude information obtained by removing said first amplitude information from said amplitude information A first target determination step of determining a target based on the first amplitude information recorded in the recording unit for recording, respectively, and based on the second amplitude information recorded in the recording unit and a second target determination step of determining the target, wherein the first target determination step combines at least the first amplitude information obtained from the first received signal and the second received signal. At the same time, the target is determined based on the combined first amplitude information.

In order to solve the above-described problems and achieve an object, a program according to the present disclosure provides a computer with a first transmission signal in a first frequency band and a second frequency band having a frequency band different from the first frequency band. a transmitting step of transmitting signals in at least two or more frequency bands with a second transmission signal of; and the first transmission signal and the second transmission transmitted by the transmitting step and reflected by one or more objects a receiving step of receiving signals as a first received signal and a second received signal, respectively; and a distance calculation of calculating distance information to one or more of the objects based on the first received signal and the second received signal. a speed calculation step of calculating relative speed information with respect to one or more of the objects based on the first received signal and the second received signal; and amplitude information corresponding to the distance information or the relative speed information. A selection step of selecting amplitude information corresponding to a specific physical quantity as first amplitude information from among; said first amplitude information; and second amplitude information obtained by removing said first amplitude information from said amplitude information A first target determination step of determining a target based on the first amplitude information recorded in the recording unit for recording, respectively, and based on the second amplitude information recorded in the recording unit and a second target determination step of determining the target, wherein the first target determination step comprises at least the first received signal and the second received signal. The program combines first amplitude information and determines the target based on the combined first amplitude information.

According to the present disclosure, analysis of information between multiple received frames can be efficiently processed in a short amount of time.

FIG. 1 is a block diagram showing the configuration of a radar device. FIG. 2 is a diagram schematically showing FCM transmission signal waveforms using two types of chirp signals. FIG. 3 is a diagram schematically showing pulse transmission signal waveforms of two types of pulse signals. FIG. 4 is a diagram for explaining a processing procedure for calculating distance information. FIG. 5 is a diagram for explaining a processing procedure for calculating relative velocity information. FIG. 6 is a diagram for explaining a procedure for extracting amplitude information corresponding to a specific speed for each transmission signal and recording it in the first recording section. FIG. 7 is a diagram for explaining the saving process. FIG. 8 is a diagram for explaining processing for combining a plurality of pieces of first amplitude information. FIG. 9 is a diagram schematically showing the relationship between the frequency of a transmission signal and amplitude information (before rotation processing on the IQ plane). FIG. 10 is a diagram schematically showing the relationship between the frequency of a transmission signal and amplitude information (after rotation processing on the IQ plane). FIG. 11 is a flow chart showing the flow of processing by the radar device 1 according to the first embodiment. FIG. 12 is a flow chart showing the flow of signal processing by the radar device 1 according to the modification of the first embodiment. FIG. 13 is a block diagram showing a part of the configuration of interference countermeasures according to the second embodiment. FIG. 14 is a diagram showing an example of two-dimensional information of distance index versus amplitude value when no interference occurs and two-dimensional information of distance index versus amplitude value when interference occurs. FIG. 15 is a flow chart showing the flow of processing by the radar device 1 according to the second embodiment. FIG. 16 is a block diagram showing a part of the noise countermeasure configuration according to the third embodiment. FIG. 17 is a flow chart showing the flow of processing by the radar device 1 according to the third embodiment. FIG. 18 is a flow chart showing the procedure of an object detection method for efficiently processing the analysis of information between a plurality of received frames in a short time. FIG. 19 is a diagram showing the configuration of a computer. FIG. 20 is a diagram showing another configuration of the computer.

Next, embodiments of the present invention will be described.

(Regarding the first embodiment)
(Configuration and operation of radar equipment)
FIG. 1 is a block diagram showing the configuration of a radar device 1 according to the present invention. The radar device 1 according to the present invention uses an FCM (Fast Chirp Modulation) method for detecting physical quantities (for example, distance and relative velocity) related to the object T1 by transmitting a chirp wave whose frequency continuously increases or decreases. Although explained, it is not limited to the FCM method, and may be a pulse method.

Here, the FCM method will be explained. FIG. 2 is a diagram schematically showing FCM transmission signal waveforms using two types of chirp signals. In the case of the FCM method, at least one chirp signal f1 is transmitted as the transmission signal S1, and the period for receiving the electromagnetic wave (first reception signal R1) reflected by the object T1 and the start frequency different from the transmission signal S1. , at least one chirp signal f2 having an end frequency is transmitted as a transmission signal S2, and a period for receiving an electromagnetic wave (second reception signal R2) reflected by the object T1 is provided. The chirp signal f1 has a starting frequency fa1 and an ending frequency fb1. The chirp signal f2 has a starting frequency fa2 and an ending frequency fb2.

Next, the case of the pulse system will be explained. FIG. 3 is a diagram schematically showing pulse transmission signal waveforms of two types of pulse signals. In the pulse method, after a predetermined number (P1-PM) of pulse signals are transmitted at the center frequency fc1, a predetermined number (P1'-PM') of pulse signals with a center frequency fc2 different from the center frequency fc1 are transmitted.

The radar device 1, as shown in FIG. It includes a unit 31 , a storage processing unit 32 , a second target determination unit 25 , a first target determination unit 34 , and an angle calculation unit 35 .

The transmitter 2 transmits signals in at least two or more frequency bands, a first transmission signal S1 in a first frequency band and a second transmission signal S2 in a second frequency band having a frequency band different from the first frequency band. do. Specifically, the transmission section 2 includes a transmission antenna 11 , a transmission control section 13 , a signal generation section 14 and an oscillator 15 . Note that the transmission unit 2 may be configured to transmit three or more types of transmission signals in different frequency bands.

The transmission controller 13 controls the signal generator 14 . The signal generator 14 generates a transmission signal (for example, chirp signal) of a predetermined frequency under the control of the transmission controller 13 . The oscillator 15 modulates the transmission signal into a predetermined high frequency signal. The transmission antenna 11 radiates into space a transmission signal that has been modulated into a high-frequency signal. At least one transmitting antenna 11 is provided.

The receiving unit 3 receives the first transmission signal S1 and the second transmission signal S2 that are transmitted by the transmission unit 2 and reflected by one or more objects as a first reception signal R1 and a second reception signal R2, respectively. . Specifically, the receiving section 3 includes a receiving antenna 12 and a mixer 16 . The receiving antenna 12 receives the signal reflected by the object T1. At least one receiving antenna 12 is provided. The mixer 16 mixes the received first received signal R1 and the first transmitted signal S1, and mixes the received second received signal R2 and the second transmitted signal S2 to calculate the distance between the radar device 1 and the object T1. generates a beat signal with a beat frequency proportional to

The ADC 21 converts the analog beat signal supplied from the receiver 3 (mixer 16) into a digital signal.

The distance calculator 22 calculates distance information with respect to one or more objects T1 based on the first received signal R1 and the second received signal R2. In the case of the FCM method, the distance calculator 22 calculates distance information with one or more objects based on the frequency of the beat signal generated from the first received signal R1 and the second received signal R2. The first received signal R1 and the second received signal R2 are converted into digital data by the ADC 21 .

The speed calculator 23 calculates relative speed information with respect to one or more objects based on the first received signal R1 and the second received signal R2. In the case of the FCM method, the speed calculator 23 calculates relative speed information with respect to one or more objects based on the phase change of the beat signal generated from the first received signal R1 and the second received signal R2. . Note that, in this embodiment, the velocity calculation unit 23 calculates the distance to one or more objects based on the distance information to the one or more objects calculated by the distance calculation unit 22 and recorded in the recording unit 4. However, it is not limited to this configuration, and based on the first received signal R1 and the second received signal R2 supplied from the ADC 21, one or more objects A configuration for calculating relative velocity information may be used.

The selection unit 31 selects amplitude information corresponding to a specific physical quantity from amplitude information corresponding to distance information or relative velocity information as first amplitude information. Although the detailed operation of the selection unit 31 will be described later, the specific physical quantity is mainly specified speed information, but is not limited to the specified speed information, and may be specified distance information or the like. .

The recording unit 4 records the first amplitude information and the second amplitude information obtained by removing the first amplitude information from the amplitude information.

The first target determination section 34 performs target determination based on the first amplitude information recorded in the recording section 4 . The first target determination unit 34 combines the first amplitude information obtained from at least the first received signal R1 and the second received signal R2, and determines the target based on the combined first amplitude information. conduct. Combining means a process of rotating at least one of the first amplitude information on the IQ plane, which will be described later in detail, calculating the average value of the first amplitude information, adding or multiplying the first amplitude information, This is a concept including taking the difference of the first amplitude information.

A second target determination unit 25 determines a target based on the second amplitude information recorded in the recording unit 4 .

The angle calculator 35 obtains the target angle based on the determination result of the first target determination unit 34 and the determination result of the second target determination unit 25 . The angle calculator 35 uses a predetermined method such as ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), DBF (Digital Beam Forming), or MUSIC (Multiple Signal Classification). to find the angle.

In this manner, the first target determination unit 34 of the radar apparatus 1 combines the first amplitude information, determines the target based on the combined first amplitude information, and determines the second target. Since the determination unit 25 determines the target based on the second amplitude information, it is possible to efficiently analyze the information between the received frames in a short time.

(Regarding the processing procedure for calculating distance information)
Here, a processing procedure for calculating distance information will be described. FIG. 4 is a diagram for explaining a processing procedure for calculating distance information.

The ADC 21 converts the analog beat signal supplied from the mixer 16 into a digital signal based on the predetermined sampling number N. "21a" shown in FIG. 4 schematically shows a beat signal converted into a digital signal with the sampling number N. As shown in FIG.

Also, the beat frequency of the beat signal is proportional to the distance. The distance calculator 22 analyzes, for example, FFT (Fast Fourier Transform) of the beat signal converted into a digital signal by the ADC 21 . FFT analysis provides frequency information fr. The distance calculator 22 converts the obtained frequency information fr into a distance index corresponding to distance information. Note that distance information in a predetermined range is converted into one distance index. At this time, amplitude information Ir corresponding to each distance index can be obtained together. "22a" shown in FIG. 4 schematically indicates a distance index corresponding to distance information.

Here, the amplitude information Ir is a complex signal. Actually, the signal output from the mixer 16 is demodulated into an I component signal (real signal) and a Q component signal (complex signal). A beat signal may be either a real signal or a complex signal. When the beat signal is a real signal, a complex signal (amplitude information Ir) can be obtained by performing FFT analysis.

The distance calculator 22 performs FFT analysis for each chirp for each receiving antenna 12 (for each antenna number), and converts the obtained frequency information fr into a distance index. The distance calculation unit 22 records the obtained amplitude information Ir in the recording unit 4 (specifically, the second recording unit 24 described later) for each antenna number, chirp number, and distance index. "24a" shown in FIG. 4 schematically shows the amplitude information group Ir_g recorded for each antenna number, chirp number, and distance index.

(Regarding the processing procedure for calculating relative velocity information)
Next, a processing procedure for calculating the relative speed information by the speed calculator 23 will be described. FIG. 5 is a diagram for explaining a processing procedure for calculating relative velocity information.

If there is a relative velocity between the radar device 1 and the object T1, the Doppler effect causes a frequency shift between the chirp signals. The velocity calculation unit 23 extracts the amplitude information Ir by the number of chirp numbers (M in the example shown in FIG. 5) for each distance index corresponding to the antenna number from the recording unit 4, and converts the extracted amplitude information Ir to, for example, , FFT analysis. FFT analysis provides frequency information fs. The speed calculator 23 converts the obtained frequency information fs into a speed index corresponding to relative speed information. It should be noted that the relative velocity information within a predetermined range is converted into one velocity index. At this time, amplitude information Is corresponding to each velocity index can be obtained together. "23a" shown in FIG. 5 schematically indicates a speed index corresponding to relative speed information.

The velocity calculator 23 performs FFT analysis for each distance index for each antenna number, and converts the obtained frequency information fs into a velocity index. The speed calculation unit 23 stores the obtained amplitude information Is (corresponding to the first amplitude information) for each antenna number, distance index, and speed index to the recording unit 4 (specifically, the second recording unit 24 described later). Record. Note that the speed calculation unit 23 updates (overwrites) the amplitude information Is obtained by the speed calculation to the same location (address) as the location (address) where the amplitude information Ir read out when performing the speed calculation is recorded. )do. "24b" shown in FIG. 5 schematically shows the amplitude information group Is_g recorded for each antenna number, speed index, and distance index.

(Regarding the configuration and operation of the recording unit)
As shown in FIG. 1, the recording section 4 is composed of a first recording section 33 for recording first amplitude information and a second recording section 24 for recording second amplitude information.

Although the details will be described later, the first recording unit 33, when the frequency band of the already recorded first amplitude information and the frequency band of the newly selected first amplitude information are the same, the old first amplitude information is updated to the newly selected first amplitude information and recorded.

In addition, although the details will be described later, if the frequency band of the first amplitude information already recorded differs from the frequency band of the newly selected first amplitude information, the first recording unit 33 Record information in different areas.

Here, a procedure for recording the first amplitude information (hereinafter also referred to as amplitude information Is) in the first recording section 33 will be described. FIG. 6 is a diagram for explaining a procedure for extracting amplitude information Is corresponding to a specific speed for each transmission signal and recording it in the first recording section 33. As shown in FIG. In the following description, two types of transmission signals, that is, transmission signal S1 and transmission signal S2 having different center frequencies will be described, but three or more types may be used.

As shown in FIG. 6, the second recording section 24 records an amplitude information group Is_g1 corresponding to the transmission signal S1 and an amplitude information group Is_g2 corresponding to the transmission signal S2.

The selection unit 31 extracts the amplitude information Is at a specific speed (for example, the relative speed is 0 [m/s]) from the second recording unit 24 . Specifically, the selector 31 extracts amplitude information Is_1 of a specific speed from the amplitude information group Is_g1 corresponding to the transmission signal S1, and amplitude information of a specific speed from the amplitude information group Is_g2 corresponding to the transmission signal S2. Fetch Is_2.

The storage processing unit 32 stores the amplitude information Is_1 extracted from the amplitude information group Is-g1 corresponding to the transmission signal S1 in the area d1 of the first recording unit 33, and stores the amplitude information group Is-g2 corresponding to the transmission signal S2. is stored in the area d2 of the first recording unit 33.

In addition, when the transmission signal S1n has the same frequency band as the transmission signal S1, the storage processing unit 32 saves the amplitude information Is_1n extracted from the amplitude information group Is-g1n corresponding to the transmission signal S1n to the area d1 of the first recording unit 33. Save (overwrite) to When the transmission signal S2n has the same frequency band as the transmission signal S2, the storage processing unit 32 stores the amplitude information Is_2n extracted from the amplitude information group Is-g2n corresponding to the transmission signal S2n in the area d2 of the first recording unit 33. (Overwrite.

FIG. 7 is a diagram for explaining the save processing of the save processing unit 32. As shown in FIG. Below shown in FIG. 7, the amplitude information group is also referred to as a frame. Odd-numbered frames (“frame 1” and “frame n” shown in FIG. 7) correspond to transmission signals in the same frequency band as the transmission signal S1, and even-numbered frames (“frame 2” and “frames” shown in FIG. 7). m") corresponds to a transmission signal in the same frequency band as the transmission signal S2.

The storage processing section 32 records the amplitude information extracted from the frame 1 in the area d1 of the first recording section 33 . The storage processing section 32 records the amplitude information extracted from the frame 2 in the area d2 of the first recording section 33 . The first target determination section 34 performs target determination based on the amplitude information recorded in the areas d1 and d2 of the first recording section 33 . The amplitude information extracted from each frame by the storage processing unit 32 is recorded in the areas d1 and d2 of the first recording unit 33, and then the first target determination unit 34 performs target determination. Repeated for the number of times. Further, when the amplitude information is recorded in the areas d1 and d2 of the first recording section 33, the storage processing section 32 stores the amplitude information extracted from the next frame in the areas d1 and d2 of the first recording section 33. overwrite the That is, the storage processing unit 32 overwrites the amplitude information extracted from the odd-numbered frame (frame n) in the area d1 of the first recording unit 33, and stores the amplitude information extracted from the even-numbered frame (frame m) in the first recording. Overwrite recording is performed in the area d2 of the section 33 . When the amplitude information is recorded in the same area, it is not limited to overwriting. Old amplitude information already recorded and new amplitude information may be averaged, and the average value may be recorded. The old amplitude information and the new amplitude information may be added or integrated, and the added or integrated value may be recorded.

(About rotation processing)
Next, the process of combining the first amplitude information obtained from the first received signal R1 and the second received signal R2 will be described. FIG. 8 is a diagram for explaining processing for combining a plurality of pieces of first amplitude information. In the following, as an example of composite processing, processing for rotating on the IQ plane will be described.

The radar device 1 includes a rotation processing section 41 and an arithmetic processing section 42, as shown in FIG. The rotation processing unit 41 converts the first amplitude obtained from the transmission signal in the first frequency band according to the predetermined phase angle corresponding to at least one predetermined distance and the first frequency band or the second frequency band. At least one of the information and the first amplitude information obtained from the transmission signal of the second frequency band is rotated on the IQ plane.

The arithmetic processing unit 42 adds the first amplitude information obtained from the transmission signal of the first frequency band, at least one of which is rotated by the rotation processing unit 41, and the first amplitude information obtained from the transmission signal of the second frequency band. or subtract. The first target determination unit 34 performs target determination based on the results processed by the arithmetic processing unit 42 .

By being configured in this way, the radar device 1 can erase the information about the target at a known distance by the rotation processing by the rotation processing unit 41 , so that the first target determination unit 34 can detect the target object. In the determination process, target determination can be performed by narrowing down to objects other than the target at a known distance.

Further, when performing the process of rotating on the IQ plane, the rotation processing unit 41 includes relative velocity information, which is a specific physical quantity, and a The amount of rotation may be corrected based on time. In such a case, the radar device 1 performs rotation processing on the IQ plane in consideration of the Doppler shift determined from the specific speed when the specific speed, which is a specific physical quantity, is other than 0 [m/s]. be able to.

The predetermined distance is selected so as to correspond to the distance of at least one target from among at least one or more targets obtained by performing target determination by the second target determination unit 25. It may be a distance.

When the rotation processing unit 41 performs rotation processing on the IQ plane using two types of frequencies, only one distance component can be removed (erased), and rotation processing on the IQ plane using three types of frequencies. When the processing is performed, two distance components can be removed (erased). That is, when rotation processing is performed on the IQ plane using n types of frequencies (n is a natural number equal to or greater than 1), the number of distance components that can be removed (erased) is "n-1". Therefore, as the number of transmission signals with different frequencies increases, the number of distance components that can be removed (erased) also increases.

If the radar device 1 is mounted on a vehicle, the predetermined distance may be a distance selected to correspond to the distance from the radar device 1 to the bumper of the vehicle.

When the radar device 1 is placed inside the bumper of the vehicle, the radar device 1 receives signals reflected by various targets including the bumper. The distance between the radar device 1 and the pan bar can be measured in advance. Therefore, if the predetermined distance is selected to correspond to the distance from the radar device 1 to the bumper, the rotation processing unit 41 and the arithmetic processing unit 42 remove the distance component from the radar device 1 to the bumper ( erasure).

The rotation processing unit 41 processes a speed of n [m/s] (n is a number of 0 or more) relative to one or more objects as a specific physical quantity.

Therefore, the radar device 1 can process relative velocities with respect to one or more objects, including relative velocities of 0 [m/s] (stationary objects such as bumpers), as specific physical quantities. .

The rotation processing unit 41 converts at least one determination result of the first target determination unit 34 in the velocity direction for each distance from one or more targets to the first amplitude information selected by the selection unit 31. select the velocity of at least one target from among the targets, and process the selected velocity as a specific physical quantity. The speed of at least one target is, for example, the speed of the fastest moving target, but is not limited to this.

Here, the amplitude information Is_1 extracted from the amplitude information group Is-g1 corresponding to the transmission signal S1 is stored in the area d1 of the first recording unit 33, and the amplitude information extracted from the amplitude information group Is-g2 corresponding to the transmission signal S2 is stored in the area d1. Specific operations of the rotation processing unit 41 and the arithmetic processing unit 42 in a state where the information Is_2 is stored in the area d2 of the first recording unit 33 will be described. In the following, it is assumed that the first object exists at a position separated by a distance L1 from the radar device 1 and the second object exists at a position separated by a distance L2. Also, the radar device 1 assumes two types of transmission signals, a transmission signal S1 with a frequency f1 and a transmission signal S2 with a frequency f2. Let k1 (=2πf1n/c) be the wavenumber for frequency f1n at the timing of sample number n of ADC 21, and let k2 (=2πf2n/c) be the wavenumber for frequency f2n at the timing of sample number n of ADC 21. Note that c indicates the speed of light.

FIG. 9 is a diagram schematically showing the relationship between the frequency of a transmission signal and amplitude information (before rotation processing on the IQ plane). FIG. 10 is a diagram schematically showing the relationship between the frequency of a transmission signal and amplitude information (after rotation processing on the IQ plane).

The difference between frequency f1n and frequency f2n corresponds to the difference between the start frequency or the center frequency of frequency band f1 and frequency band f2, and is constant regardless of the sampling timing of ADC 21 .

Any point in the IQ plane can be denoted by A×exp(iθ). where A indicates amplitude, i indicates imaginary number, and θ indicates phase angle. In the following explanation, the amplitude A is assumed to be "1" for the sake of simplicity.

In such a case, the detection signal by the frequency band f1n is represented by the following formula (1). Note that the first term of the equation (1) corresponds to the arrow of the solid line T1 shown in FIG. Also, the second term of the equation (1) corresponds to the arrow of the solid line T2 in FIG.
exp(i×k1×L1)+exp(i×k1×L2) (1)

Also, the detection signal at the frequency f2n is represented by Equation (2). Note that the first term of the equation (2) corresponds to the arrow of the dashed line T1' in FIG. The second term of equation (2) corresponds to the arrow of dashed line T2' in FIG.
exp(i×k2×L1)+exp(i×k2×L2) (2)

Here, assuming that k2=k1+Δk, Equation (2) is transformed into Equation (3) below.
exp(i×k1×L1)×exp(i×Δk×L1)+exp(i×k1×L2)×exp(i×Δk×L2) (3)

Further, by multiplying the expression (3) by exp(-i×Δk×L1), the expression (4) is obtained. It should be noted that multiplying exp(-i×Δk×L1) by equation (3) means that on the IQ plane, the detection result at frequency f2n shown in FIG. (Fig. 10).
exp(i×k1×L1)+exp(i×k1×L2)×exp(i×Δk(L2−L1)) (4)

Further, the arithmetic processing unit 42 obtains the following formula (5) by subtracting the formula (4) from the formula (1).
exp(i×k2×L2)−exp(i×k1×L2)×exp(i×Δk(L2−L1)) (5)

If the distance L1 is known, the term for the first object can be eliminated and only information for the second object can be obtained. The distance L1 is the distance between the bumper and the radar device 1, for example.

Note that the arithmetic processing unit 42 may perform addition processing instead of subtraction processing. In this case, the signal component of the first object with the same phase is doubled, while the signal component of the second object is less than doubled because the phase is different. Therefore, the component related to the first object can be emphasized.

Also, if the specific speed is other than 0 [m/s], it is necessary to consider the Doppler shift fd determined from this specific speed. The phase Δφs that changes during the time Δts from transmission signal S1 to transmission signal S2 can be expressed by equation (6).
Δφs=2πfdΔts (6)

The rotation processing unit 41 can perform rotation processing on the IQ plane while also considering the Doppler shift by adding Equation (6), which considers phase changes, to Equation (4).

Here, the process of the first embodiment in which the transmission signal S1 and the transmission signal S2 are alternately and repeatedly transmitted will be described. FIG. 11 is a flow chart showing the flow of processing by the radar device 1 according to the first embodiment. Although the FCM method will be described below, the present invention is not limited to the FCM method and may be a pulse method.

In step ST11, the transmitter 2 sets the first frequency band f1.

In step ST12, the transmission section 2 performs transmission processing. Specifically, the transmitter 2 transmits the transmission signal S1 in the first frequency band f1.

In step ST13, the receiver 3 performs reception processing. Specifically, the receiver 3 receives the reflected signal R1. The ADC 21 converts an analog beat signal into a digital signal.

In step ST14, the distance calculation section 22 performs distance calculation processing. Specifically, the distance calculator 22 performs FFT analysis on the beat signal converted into a digital signal by the ADC 21 . FFT analysis provides frequency information fr. The distance calculator 22 converts the obtained frequency information fr into a distance index corresponding to distance information. At this time, amplitude information Ir corresponding to each distance index can be obtained together.

In step ST15, the speed calculator 23 performs speed calculation processing. Specifically, the velocity calculator 23 extracts the amplitude information Ir by the number of chirp numbers for each distance index, and performs FFT analysis on the extracted amplitude information Ir. FFT analysis provides frequency information fs. The speed calculator 23 converts the obtained frequency information fs into a speed index corresponding to relative speed information. At this time, amplitude information Is corresponding to each velocity index can be obtained together. The selector 31 selects the amplitude information Is corresponding to the predetermined speed information as the first amplitude information.

In step ST21, the amplitude information Is selected by the selector 31 is saved (recorded) in the area d1 of the recorder 4 (first recorder 33). For example, when the specific speed condition for extracting the amplitude information Is by the selector 31 is zero relative speed, the selector 31 extracts the amplitude information Is for zero relative speed. In the area d1 of the first recording unit 33, the amplitude information Is (corresponding to the first amplitude information) of this zero relative velocity is stored. The second recording unit 24 stores the amplitude information Is (corresponding to the second amplitude information) from which the amplitude information Is of zero relative velocity is removed.

In step ST22, the rotation processing section 41 determines whether or not the amplitude information Is is stored in the area d2 of the first recording section 33. FIG. Note that the storage processing unit 32 or the like may determine whether or not the amplitude information Is is stored in the area d2. If the amplitude information Is is stored in the area d2 (Yes), the process proceeds to step ST23, and if the amplitude information Is is not stored in the area d2 (No), the process proceeds to step ST17. If the processes after step ST31, which will be described later, have not been performed even once, the amplitude information Is is not stored in the area d2.

In step ST23, the rotation processing section 41 performs rotation processing on the IQ plane using the amplitude information Is recorded in the area d1 and the amplitude information Is recorded in the area d2.

In step ST24, the arithmetic processing unit 42 performs arithmetic (addition or subtraction) based on the result of the rotation processing.

In step ST25, the first target determination unit 34 performs first target determination. Specifically, the first target determination unit 34 performs peak detection on the amplitude information Is (first amplitude information) of the zero relative velocity after being arithmetically processed by the arithmetic processing unit 42 . Peak detection is performed using a predetermined detection method such as CFAR (Constant False Alarm Rate).

In step ST16, the second target determination unit 25 performs second target determination. Specifically, the second target determination unit 25 performs peak detection on the amplitude information Is (second amplitude information) from which the amplitude information Is of zero relative velocity recorded in the second recording unit 24 has been removed. I do.

In step ST17, the angle calculation unit 35 performs angle calculation processing based on the result of the first target determination in the process of step ST25 and the result of the second target determination in the process of step ST16. . Specifically, the angle calculator 35 calculates the angle of the target based on the phase information obtained from the amplitude information of each antenna at least one of the distance and speed at which the peak is detected in the processes of steps ST25 and ST16. demand. The angle calculator 35 obtains the angle using a predetermined method such as ESPRIT, DBF, or MUSIC.

In step ST31, the transmitter 2 sets the second frequency band f2.

In step ST32, the transmission section 2 performs transmission processing. Specifically, the transmitter 2 transmits the transmission signal S2 in the second frequency band f2.

In step ST33, the receiver 3 performs reception processing. Specifically, the receiver 3 receives the reflected signal R2. The ADC 21 converts an analog beat signal into a digital signal.

In step ST34, the distance calculation section 22 performs distance calculation processing. Specifically, the distance calculator 22 performs FFT analysis on the beat signal converted into a digital signal by the ADC 21 . FFT analysis provides frequency information fr. The distance calculator 22 converts the obtained frequency information fr into a distance index corresponding to distance information. At this time, amplitude information Ir corresponding to each distance index can be obtained together.

In step ST35, the speed calculator 23 performs speed calculation processing. Specifically, the velocity calculator 23 extracts the amplitude information Ir by the number of chirp numbers for each distance index, and performs FFT analysis on the extracted amplitude information Ir. FFT analysis provides frequency information fs. The speed calculator 23 converts the obtained frequency information fs into a speed index corresponding to relative speed information. At this time, amplitude information Is corresponding to each velocity index can be obtained together. As in step ST15, the selection unit 31 selects the amplitude information Is corresponding to the predetermined speed information as the first amplitude information.

In step ST41, the amplitude information Is selected by the selector 31 is saved (recorded) in the area d2 of the recorder 4 (first recorder 33). For example, when the specific speed condition for extracting the amplitude information Is by the selector 31 is zero relative speed, the selector 31 extracts the amplitude information Is for zero relative speed. In the area d2 of the first recording section 33, the amplitude information Is (corresponding to the first amplitude information) of this zero relative velocity is stored. The second recording unit 24 stores the amplitude information Is (corresponding to the second amplitude information) from which the amplitude information Is of zero relative velocity is removed.

In step ST43, the rotation processing section 41 performs rotation processing on the IQ plane using the amplitude information Is recorded in the area d1 and the amplitude information Is recorded in the area d2.

In step ST44, the arithmetic processing unit 42 performs arithmetic (addition or subtraction) based on the result of the rotation processing.

In step ST45, the first target determination unit 34 performs first target determination. Specifically, the first target determination unit 34 performs peak detection on the amplitude information Is (first amplitude information) of zero relative velocity recorded in the first recording unit 33 .

In step ST36, the second target determination unit 25 performs second target determination. Specifically, the second target determination unit 25 performs peak detection on the amplitude information Is (second amplitude information) from which the amplitude information Is of zero relative velocity recorded in the second recording unit 24 has been removed. I do.

In step ST37, the angle calculation unit 35 performs angle calculation processing based on the result of the first target determination in the process of step ST45 and the result of the second target determination in the process of step ST36. . Specifically, the angle calculator 35 calculates the angle of the target based on the phase information obtained from the amplitude information of each antenna at least one of the distance and speed at which the peak is detected in steps ST45 and ST36. demand.

In this manner, the first target determination unit 34 of the radar apparatus 1 combines the first amplitude information obtained from at least the first received signal R1 and the second received signal R2, and the combined first amplitude information The target is determined based on the amplitude information, and the second target determining unit 25 determines the target based on the second amplitude information. Since frame data is not created, information analysis between a plurality of received frames can be efficiently processed in a short time.

(Regarding modification of the first embodiment)
Further, a specific speed condition for extracting (selecting) the amplitude information Is from the first recording section 33 may be variable. Modifications of the above-described first embodiment will be described below. FIG. 12 is a flow chart showing the flow of signal processing by the radar device 1 according to the modification of the first embodiment. Processes (steps) that are the same as those in the first embodiment are assigned the same numbers, and detailed description thereof is omitted.

Steps ST11 to ST16 perform the same processing as in the first embodiment.

In step ST51, the second target determination section 25 determines whether or not one or more targets exist based on the result of the second target determination in the process of step ST16. If one or more targets exist (Yes), the process proceeds to step ST21, and if one or more targets do not exist (No), the process returns to step ST11.

In step ST<b>21 , the selection unit 31 sets the speed index of the target Tm having the largest amplitude information to a specific speed Vm, and extracts the amplitude information Is of the speed Vm from the second recording unit 24 . The storage processing section 32 stores this amplitude information Is_21 in the area d1 of the first recording section 33 .

Further, in step ST17, the angle calculation section 35 performs angle calculation processing. The angle calculator 35 may, for example, set the distances of the targets in descending order of amplitude among the plurality of targets detected in the second target determination in step ST16 as the predetermined distance. In this case, the angle calculation unit 35 performs angle calculation processing for targets other than the target Tm having the largest amplitude information.

Steps ST31 to ST37 perform the same processing as in the first embodiment.

In step ST41, the selector 31 retrieves the amplitude information Is of the specific velocity Vm from the second recorder . The storage processing unit 32 stores the extracted amplitude information Is_22 in the area d2 of the first recording unit 33 .

In step ST43, the rotation processing section 41 performs rotation processing on the IQ plane using the amplitude information Is_21 recorded in the area d1 and the amplitude information Is_22 recorded in the area d2.

Steps ST44 and ST45 perform the same processing as in the first embodiment.

The above description is an example, and needless to say, the present invention is not limited to the case described above. For example, in the first embodiment, transmission signals in two types of frequency bands are transmitted, and these received signals are subjected to rotation processing and arithmetic processing (addition or subtraction). A transmission signal may be transmitted, and these reception signals may be rotated and arithmetically processed (added or subtracted). Note that even when there are three or more frequencies, the component related to the object can be emphasized or suppressed by the same processing as in the case of two frequencies. In addition, when transmitting a plurality of signals with different frequencies, the configuration may be such that the frequency band is changed each time the signal is transmitted, or one signal is transmitted and different frequency components in this signal are used. may be configured.

In addition, when transmitting a plurality of frequency signals in the pulse method, the frequency distribution for transmitting the pulse signal may be changed each time it is transmitted, or one pulse signal may be transmitted and You may make it perform a process by a mutually different frequency component in. In such a case, a plurality of frequency components are oscillated at the same time, but the addition or subtraction processing may be performed after receiving a plurality of reception signals or after receiving them at the same time.

(Regarding the second embodiment_countermeasures against interference)
Here, the amplitude information stored in the first recording unit 33 may be used for interference countermeasures. FIG. 13 is a block diagram showing a part of the configuration of interference countermeasures according to the second embodiment.

The radar device 1 includes an amplitude difference acquisition section 51 and an interference detection section 52 . In addition, the transmission unit 2, the reception unit 3, the recording unit 4, the ADC 21, the distance calculation unit 22, the speed calculation unit 23, the selection unit 31, the storage processing unit 32, and the second target determination unit 25 , the first target determination unit 34, and the angle calculation unit 35 are the same in configuration and operation as in the above-described embodiment.

The amplitude difference acquisition unit 51 acquires an amplitude difference within a predetermined distance range based on the first amplitude information obtained from the first received signal R1 and the first amplitude information obtained from the second received signal R2. . It is assumed that the first amplitude information obtained from the first received signal R1 is recorded in the area d1 of the first recording section 33 as the amplitude information Is_21. It is also assumed that the second amplitude information obtained from the second received signal R2 is recorded in the area d2 of the first recording section 33 as the amplitude information Is_22.

The interference detection unit 52 detects occurrence of interference when the amplitude difference acquired by the amplitude difference acquisition unit 51 is equal to or greater than a predetermined threshold. Further, the interference detection unit 52 discards the first amplitude information recorded in the recording unit 4 when the occurrence of interference is detected. When the first amplitude information is discarded, the interference detection unit 52 instructs the first target determination unit 34 and the second target determination unit 25 not to perform target determination.

Interference countermeasures according to this embodiment will be specifically described below. Here, as an example, a case where two types of transmission signals are used will be described, but three or more types of transmission signals may be used. When three or more types of transmission signals are used, three or more types of reception signals are also used, and each first amplitude information is recorded in areas d1 to dx of the first recording section 33, respectively.

The amplitude information Is_21 of the complex signal recorded in the area d1 and the amplitude information Is_22 of the complex signal recorded in the area d2 are converted into absolute values, and the average between the antennas is calculated to obtain the distance index vs. amplitude value. Two-dimensional information can be created. FIG. 14 is a diagram showing an example of two-dimensional information of distance index versus amplitude value when no interference occurs and two-dimensional information of distance index versus amplitude value when interference occurs. FIG. 14A shows an example in which interference occurs in the two-dimensional information of the distance index versus amplitude value based on the amplitude information Is_21. Also, FIG. 14B shows an example in which interference occurs in the two-dimensional information of the distance index versus the amplitude value based on the amplitude information Is_22.

When receiving interference from other radars and receiving a stronger signal than the reflected signal from the target, the noise level increases over all range indices, as shown in FIG. 14B, because the frequency is also not constant. Therefore, it is possible to determine the presence or absence of interference by comparing the noise level within an arbitrary distance index range obtained from the received signal of each frequency band. It should be noted that the term "combination" as used in the present invention is a concept that includes comparison of noise levels within an arbitrary distance index range.

For example, the amplitude difference acquisition unit 51 obtains the noise level Na in an arbitrary distance index range in the two-dimensional information of the distance index vs. amplitude value based on the amplitude information Is_21, and the two-dimensional information of the distance index vs. amplitude value based on the amplitude information Is_22. Compare the information with the noise level Nb in any distance index range to obtain the difference between the noise level Na and the noise level Nb.

The interference detection unit 52 detects that interference occurs when the noise level difference acquired by the amplitude difference acquisition unit 51 is equal to or greater than a predetermined threshold. Note that the interference detection unit 52 may compare the integrated value or the average value of the amplitude values of all the distance indexes, and detect the presence or absence of interference based on the result.

Here, the processing of the second embodiment (countermeasure against interference) in which the transmission signal S1 and the transmission signal S2 are alternately and repeatedly transmitted will be described. FIG. 15 is a flow chart showing the flow of processing by the radar device 1 according to the second embodiment. Although the FCM method will be described below, the present invention is not limited to the FCM method and may be a pulse method.

Steps ST11 to ST15 and steps ST21 to ST22 are the same as those in the first embodiment.

In step ST27, the amplitude difference acquisition section 51 performs interference processing. Specifically, the amplitude difference acquisition unit 51 generates two-dimensional information of the distance index versus amplitude value based on the amplitude information Is_21 stored in the area d1 of the first recording unit 33, Based on the amplitude information Is_22 of the area d2 of the section 33, two-dimensional information of distance index versus amplitude value is generated. The amplitude difference acquisition unit 51 compares the noise levels in an arbitrary distance index range based on the generated two-dimensional information of the two distance indexes versus the amplitude value, and acquires the noise level difference.

In step ST<b>61 , the interference detection section 52 detects the presence or absence of interference based on the difference acquired by the amplitude difference acquisition section 51 . If there is interference (Yes), proceed to step ST28, and if there is no interference (No), proceed to steps ST16 and ST25.

In step ST28, the interference detection section 52 discards the amplitude information Is_21 stored in the area d1 of the first recording section 33. FIG. Abandonment of the amplitude information Is_21 may be performed by the interference detection unit 52 or may be performed by the storage processing unit 32 that receives an instruction from the interference detection unit 52 . After that, the process proceeds to step ST31.

On the other hand, if there is no interference, as in the first embodiment, the second target determination unit 25 determines the amplitude information Is from which the amplitude information Is_21 recorded in the second recording unit 24 has been removed. Then, the second target determination is performed (step ST16). Also, the first target determination unit 34 performs the first target determination on the amplitude information Is_21 stored in the area d1 of the first recording unit 33 (step ST25).

Further, the angle calculation unit 35 performs angle calculation processing based on the result of the first target determination in the process of step ST25 and the result of the second target determination in the process of step ST16 (step ST17).

Further, steps ST31 to ST35 and ST41 perform the same processing as in the first embodiment.

In step ST42, the amplitude difference acquisition section 51 determines whether or not the amplitude information Is_21 is saved in the area d1 of the first recording section 33. FIG. Note that the storage processing unit 32 or the like may determine whether or not the amplitude information Is_21 is stored in the area d1. If the amplitude information Is_21 is stored in the area d1 (Yes), the process proceeds to step ST47, and if the amplitude information Is_21 is not stored in the area d1 (No), the process returns to step ST11.

In step ST47, the amplitude difference acquisition section 51 performs interference processing. Specifically, the amplitude difference acquisition unit 51 generates two-dimensional information of the distance index versus amplitude value based on the amplitude information Is_21 stored in the area d1 of the first recording unit 33, Based on the amplitude information Is_22 of the area d2 of the section 33, two-dimensional information of distance index versus amplitude value is generated. The amplitude difference acquisition unit 51 compares the noise levels in an arbitrary distance index range based on the generated two-dimensional information of the two distance indexes versus the amplitude value, and acquires the noise level difference.

In step ST<b>62 , the interference detection section 52 detects the presence or absence of interference based on the difference acquired by the amplitude difference acquisition section 51 . If there is interference (Yes), proceed to step ST48, and if there is no interference (No), proceed to steps S36 and ST45.

In step ST48, the interference detection section 52 discards the amplitude information Is_22 stored in the area d2 of the first recording section 33. FIG. The cancellation of the amplitude information Is_22 may be performed by the interference detection unit 52, or may be performed by the storage processing unit 32 or the like that receives an instruction from the interference detection unit 52. FIG. After that, the process returns to step ST11.

On the other hand, if there is no interference, as in the first embodiment, the second target determination unit 25 determines the amplitude information Is from which the amplitude information Is_22 recorded in the second recording unit 24 has been removed. Then, the second target determination is performed (step ST36). Further, the first target determination section 34 performs the first target determination on the amplitude information Is_22 stored in the area d2 of the first recording section 33 (step ST45).

Further, the angle calculation unit 35 performs angle calculation processing based on the result of the first target determination performed in the process of step ST45 and the result of the second target determination performed in the process of step ST36 (step ST37).

In this way, the radar device 1 can compare the noise level in an arbitrary distance index range when, for example, it receives interference from another radar device and receives a signal stronger than the reflected signal from the object. , and if interference is confirmed, the target amplitude information recorded in the first recording unit 33 is discarded, and subsequent target object determination is not performed, and interference is confirmed. If there is not, target object determination is performed. Therefore, target object determination can be performed with respect to amplitude information in which interference does not occur, and interference countermeasures can be taken.

(Regarding the third embodiment_noise countermeasures)
Here, the amplitude information stored in the first recording unit 33 may be used for noise countermeasures. FIG. 16 is a block diagram showing a part of the noise countermeasure configuration according to the third embodiment.

The radar device 1 includes a calculation processing section 61 . In addition, the transmission unit 2, the reception unit 3, the recording unit 4, the ADC 21, the distance calculation unit 22, the speed calculation unit 23, the selection unit 31, the storage processing unit 32, and the second target determination unit 25 , the configuration and operation of the first target determination unit 34 and the angle calculation unit 35 are the same as those of the first embodiment.

The calculation processing unit 61 averages or integrates the first amplitude information obtained from the first received signal R1 and the first amplitude information obtained from the second received signal R2 based on the four arithmetic operations of complex numbers. Calculate The first target determination unit 34 performs target determination using the amplitude values averaged or integrated in the calculation processing unit 61 .

It is assumed that the first amplitude information obtained from the first received signal R1 is recorded in the area d1 of the first recording section 33 as the amplitude information Is_21. It is also assumed that the second amplitude information obtained from the second received signal R2 is recorded in the area d2 of the first recording section 33 as the amplitude information Is_22.

Noise countermeasures will be specifically described below. Here, as an example, a case where two types of transmission signals are used will be described, but three or more types of transmission signals may be used. When three or more types of transmission signals are used, three or more types of reception signals are also used, and each first amplitude information is recorded in areas d1 to dx of the first recording section 33, respectively.

As in the second embodiment described above, the amplitude information Is_21 of the complex signal recorded in the area d1 and the amplitude information Is_22 of the complex signal recorded in the area d2 are converted into absolute values, and the average between the antennas , one can create two-dimensional information of distance index versus amplitude value. By averaging or integrating the two-dimensional information of the distance index versus the amplitude value, the influence of noise can be suppressed.

Here, the processing of the second embodiment (noise countermeasure) in which the transmission signal S1 and the transmission signal S2 are alternately and repeatedly transmitted will be described. FIG. 17 is a flow chart showing the flow of processing by the radar device 1 according to the third embodiment. Although the FCM method will be described below, the present invention is not limited to the FCM method and may be a pulse method.

Steps ST11 to ST15, steps ST21 and ST22 perform the same processing as in the first embodiment.

In step ST26, the calculation processing section 61 performs calculation processing. Specifically, the calculation processing unit 61 averages the amplitude information Is_21 recorded in the area d1 of the first recording unit 33 and the amplitude information Is_22 recorded in the area d2 based on the four arithmetic operations of complex numbers. Integrate or integrate. The averaged or integrated information is hereinafter referred to as amplitude information Ia.

The first target determination unit 34 performs first target determination on the amplitude information Ia (step ST25). The second target determination unit 25 performs the second target determination on the amplitude information Is from which the amplitude information Is_21 recorded in the second recording unit 24 has been removed (step ST16).

Further, the angle calculation unit 35 performs angle calculation processing based on the result of the first target determination in the process of step ST25 and the result of the second target determination in the process of step ST16 (step ST17). Specifically, the angle calculation unit 35 calculates the phase obtained from the amplitude information Ia of each antenna or the amplitude information Is other than the amplitude information Is_21 at least one of the distance and speed at which the peak is detected in steps ST16 and ST25. Determine the angle of the target based on the information.

Further, steps ST31 to ST35 and ST41 perform the same processing as in the first embodiment.

In step ST46, the calculation processing section 61 performs calculation processing. Specifically, the calculation processing unit 61 averages the amplitude information Is_21 recorded in the area d1 of the first recording unit 33 and the amplitude information Is_22 recorded in the area d2 based on the four arithmetic operations of complex numbers. Integrate or integrate. The averaged or integrated information is hereinafter referred to as amplitude information Ia.

The first target determination unit 34 performs first target determination on the amplitude information Ia (step ST45). The second target determination unit 25 performs the second target determination on the amplitude information Is from which the amplitude information Is_22 recorded in the second recording unit 24 has been removed (step ST36).

Further, the angle calculation unit 35 performs angle calculation processing based on the result of the first target determination performed in the process of step ST45 and the result of the second target determination performed in the process of step ST36 (step ST37). Specifically, the angle calculator 35 calculates the phase obtained from the amplitude information Ia of each antenna or the amplitude information Is other than the amplitude information Is_22 at least one of the distance and speed at which the peak is detected in steps ST36 and ST45. Determine the angle of the target based on the information.

In this way, the radar apparatus 1 converts the amplitude information of the complex signal into an absolute value, takes the average between the antennas, creates two-dimensional information of the distance index versus the amplitude value, and converts the distance index versus the amplitude value into two-dimensional information. By averaging or integrating the dimensional information, the effects of noise can be suppressed.

(Regarding object detection method)
Next, an object detection method of the radar device 1 that efficiently processes the analysis of information between a plurality of received frames in a short time will be described. FIG. 18 is a flow chart showing the procedure of an object detection method for efficiently processing the analysis of information between a plurality of received frames in a short time.

In step ST71, the transmitting unit 2 transmits at least two frequency bands of a first transmission signal S1 in a first frequency band and a second transmission signal S2 in a second frequency band having a frequency band different from the first frequency band. (transmitting step).

In step ST72, the receiver 3 converts the first transmission signal S1 and the second transmission signal S2, which were transmitted in the process of step ST71 and reflected by one or more objects, into a first reception signal R1 and a second reception signal R1, respectively. Receive as signal R2 (receiving step).

In step ST73, the distance calculator 22 calculates distance information to one or more objects based on the first received signal R1 and the second received signal R2 (distance calculation step).

In step ST74, the speed calculator 23 calculates relative speed information with respect to one or more objects based on the first received signal R1 and the second received signal R2 (speed calculation step).

In step ST75, the selection section 31 selects amplitude information corresponding to a specific physical quantity from amplitude information corresponding to distance information or relative velocity information as first amplitude information (selection step).

In step ST76, the first target determination unit 34 records the first amplitude information and the second amplitude information obtained by removing the first amplitude information from the amplitude information in the recording unit 4. A target is determined based on the first amplitude information (first target determination step).

In step ST77, the second target determination section 25 performs target determination based on the second amplitude information recorded in the recording section 4 (second target determination step).

Further, the first target determination step combines the first amplitude information obtained from at least the first received signal R1 and the second received signal R2, and determines the target based on the combined first amplitude information. I do.

Steps ST76 and ST77 may be performed simultaneously, or step ST77 may be performed before step ST76.

According to such a configuration, in the object detection method, the first target determination step combines the first amplitude information, determines the target based on the combined first amplitude information, Since the target object is determined based on the second amplitude information by the 2-target determination process, data for one frame is not created by averaging data of a plurality of frames as in the prior art. The analysis of the information between them can be efficiently processed in a short time.

(About the program)
A program for efficiently processing the analysis of information between a plurality of received frames in a short time mainly consists of the following steps and is executed by the computer 500 (hardware).

Step 1 (transmitting step): Signals in at least two or more frequency bands, a first transmission signal S1 in a first frequency band and a second transmission signal S2 in a second frequency band having a frequency band different from the first frequency band. the process of sending

Step 2 (receiving step): receive the first transmission signal S1 and the second transmission signal S2 transmitted by the step 1 and reflected by one or more objects as a first reception signal R1 and a second reception signal R2, respectively. process to do.

Step 3 (distance calculation step): A step of calculating distance information to one or more objects based on the first received signal R1 and the second received signal R2.

Step 4 (velocity calculation step): A step of calculating relative velocity information with respect to one or more objects based on the first received signal R1 and the second received signal R2.

Step 5 (selection step): A step of selecting amplitude information corresponding to a specific physical quantity from amplitude information corresponding to distance information or relative velocity information as first amplitude information.

Step 6 (First Target Determining Step): The first amplitude information and the second amplitude information obtained by subtracting the first amplitude information from the amplitude information are recorded in the recording unit 4, respectively. making a target determination based on the amplitude information;

Step 7 (second target determination step): a step of performing target determination based on the second amplitude information recorded in the recording unit 4 .

In step 6, the first amplitude information obtained from at least the first received signal R1 and the second received signal R2 is combined, and the target is determined based on the combined first amplitude information.

Steps 6 and 7 may be performed simultaneously, or step 7 may be performed before step 6.

Here, the configuration and operation of computer 500 will be described with reference to the drawings. FIG. 19 is a diagram showing the configuration of the computer 500. As shown in FIG. The computer 500 is configured by connecting a processor 501, a memory 502, a storage 503, an input/output I/F 504, and a communication I/F 505 on a bus A, as shown in FIG. The cooperation of each of these components implements the functions and/or methods described in this disclosure.

The memory 502 is composed of a RAM (Random Access Memory). RAM consists of volatile memory or non-volatile memory.

The storage 503 is composed of a ROM (Read Only Memory). The ROM is composed of non-volatile memory, and is realized by, for example, HDD (Hard Disc Drive), SSD (Solid State Drive), or Flash Memory. The storage 503 corresponds to the recording unit 4 described above. The storage 503 stores various programs such as the programs implemented in steps 1 to 7 described above.

An RF circuit 600 is connected to the input/output I/F 504 . One or more transmitting antennas 11 and one or more receiving antennas 12 are connected to the RF circuit 600 . The RF circuit 600 has functions such as a signal generator 14 that generates a transmission signal of a predetermined frequency, an oscillator 15 that modulates the transmission signal into a predetermined high-frequency signal, and a mixer 16 that mixes the reception signal and the transmission signal. .

Processor 501 controls the overall operation of computer 500 . The processor 501 is an arithmetic device that loads an operating system and various programs that implement various functions from the storage 503 into the memory 502 and executes instructions included in the loaded programs.

Specifically, when receiving a user operation, the processor 501 reads a program (for example, a program according to the present invention) stored in the storage 503, expands the read program in the memory 502, and executes the program. do. Further, the processor 501 executes the processing program to perform the transmission control unit 13, the ADC 21, the distance calculation unit 22, the speed calculation unit 23, the selection unit 31, the storage processing unit 32, the second target determination unit Each function of the unit 25, the first target determination unit 34, the angle calculation unit 35, the rotation processing unit 41, the calculation processing unit 42, the amplitude difference acquisition unit 51, the interference detection unit 52, and the calculation processing unit 61 is realized.

Here, the configuration of the processor 501 will be described. The processor 501 is implemented by, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), various other arithmetic units, or a combination thereof.

In addition, in order to implement the functions and/or methods described in the present disclosure, some or all of the functions such as the processor 501, the memory 502 and the storage 503 are dedicated hardware computers (hereinafter referred to as processing circuit) 700. FIG. 20 is a diagram showing the configuration of the processing circuit 700. As shown in FIG. Processing circuit 700 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or a combination thereof. is. An RF circuit 600 is connected to the processing circuit 700 . One or more transmitting antennas 11 and one or more receiving antennas 12 are connected to the RF circuit 600 . Note that the RF circuit 600 may also be configured as part of the processing circuit 700 .

Moreover, although the processor 501 has been described as a single component, it is not limited to this, and may be configured by a set of a plurality of physically separate processors. Programs or instructions included in the programs described herein as being executed by the processor 501 may be executed by a single processor 501 or may be executed in a distributed manner by multiple processors. . Also, a program executed by processor 501 or instructions included in the program may be executed by multiple virtual processors.

The communication I/F 505 is an interface conforming to a predetermined communication standard (for example, CAN (Controller Area Network)), and communicates with an external device (for example, ECU (Electronic Control Unit)) by wire or wirelessly.

In this way, the signal processing program is executed by the computers 500 and 700 to combine the first amplitude information in the first target determination step and to determine the object based on the combined first amplitude information. Since the target is determined and the second target determination step performs the target determination based on the second amplitude information, data for one frame is not created by averaging the data of a plurality of frames as in the prior art. Therefore, it is possible to efficiently process the analysis of information between a plurality of received frames in a short time.

As described above, some of the embodiments of the present application have been described in detail with reference to the drawings, but these are examples, and various modifications, including the embodiments described in the section of the disclosure of the present invention, can be made based on the knowledge of those skilled in the art. It is possible to carry out the present invention in other forms with modifications and improvements.

1 radar device 2 transmitter 3 receiver 4 recorder 11 transmitter antenna 12 receiver antenna 13 transmission controller 14 signal generator 15 oscillator 16 mixer 21 ADC
22 distance calculation unit 23 speed calculation unit 24 second recording unit 25 second target determination unit 31 selection unit 32 storage processing unit 33 first recording unit 34 first target determination unit 35 angle calculation unit 41 rotation processing unit 42 calculation processing Unit 51 Amplitude difference acquisition unit 52 Interference detection unit 61 Calculation processing unit

Claims (14)

a transmitter that transmits signals in at least two or more frequency bands, a first transmission signal in a first frequency band and a second transmission signal in a second frequency band having a frequency band different from the first frequency band;
a receiver that receives the first transmission signal and the second transmission signal transmitted by the transmitter and reflected by one or more objects as a first reception signal and a second reception signal, respectively;
a distance calculation unit that calculates distance information from one or more objects based on the first received signal and the second received signal;
a speed calculation unit that calculates relative speed information with respect to one or more of the objects based on the first received signal and the second received signal;
a selection unit that selects, as first amplitude information, amplitude information corresponding to a specific physical quantity from amplitude information corresponding to the distance information or the relative velocity information;
a recording unit that respectively records the first amplitude information and second amplitude information that is information obtained by removing the first amplitude information from the amplitude information;
a first target determination unit that determines a target based on the first amplitude information recorded in the recording unit;
a second target determination unit that determines the target based on the second amplitude information recorded in the recording unit;
with
The first target determination unit combines the first amplitude information obtained from at least the first received signal and the second received signal, and determines the target based on the combined first amplitude information. A radar device that makes judgments. The recording unit has a first recording unit that records the first amplitude information and a second recording unit that records the second amplitude information,
When the frequency band of the first amplitude information already recorded is the same as the frequency band of the newly selected first amplitude information, the first recording unit stores the newly selected first amplitude information. 2. The radar device according to claim 1, wherein the data is updated and recorded. The recording unit has a first recording unit that records the first amplitude information and a second recording unit that records the second amplitude information,
2. When the frequency band of the first amplitude information that has already been recorded differs from the frequency band of the newly selected first amplitude information, the first recording unit records each of the first amplitude information. Or the radar device according to 2. said first amplitude information obtained from a transmitted signal in said first frequency band in response to a predetermined phase angle corresponding to at least one predetermined distance and said first frequency band or said second frequency band; and a rotation processing unit that performs a process of rotating at least one of the first amplitude information obtained from the transmission signal of the second frequency band on an IQ plane;
addition or subtraction of the first amplitude information obtained from the transmission signal of the first frequency band, at least one of which is rotated by the rotation processing unit, and the first amplitude information obtained from the transmission signal of the second frequency band; and an arithmetic processing unit that
The radar device according to any one of claims 1 to 3, wherein the first target determination unit determines a target based on the result processed by the arithmetic processing unit. The rotation processing unit, when performing the processing of rotating on the IQ plane, the relative velocity information, which is the specific physical quantity, and the time from transmission of the first transmission signal to transmission of the second transmission signal 5. The radar device according to claim 4, wherein the amount of rotation is corrected based on time. The predetermined distance is selected so as to correspond to the distance of at least one target from among at least one or more targets obtained by performing target determination by the second target determination unit. 6. The radar system according to claim 4 or 5, wherein the distance is A radar device mounted on a vehicle,
6. A radar system according to claim 4 or 5, wherein said predetermined distance is a distance selected to correspond to a distance from said radar system to a bumper of said vehicle. 8. The rotation processing unit processes a speed of n [m/s] (n is a number equal to or greater than 0) relative to one or more objects as the specific physical quantity. 1. The radar device according to claim 1. In the first amplitude information selected by the selection unit, the rotation processing unit selects at least one result of determination by the first target determination unit with respect to a speed direction for each distance from one or more objects. 8. The radar device according to any one of claims 5 to 7, wherein the speed of at least one target is selected from among the above targets, and the selected speed is processed as the specific physical quantity. an amplitude difference acquisition unit configured to acquire an amplitude difference within a predetermined distance range based on the first amplitude information obtained from the first received signal and the first amplitude information obtained from the second received signal; ,
4. The radar device according to any one of claims 1 to 3, further comprising an interference detection unit that detects occurrence of interference when the amplitude difference acquired by the amplitude difference acquisition unit is equal to or greater than a predetermined threshold. . 11. The radar apparatus according to claim 10, wherein the interference detection section discards the first amplitude information recorded in the recording section when occurrence of interference is detected. A calculation processing unit that calculates a value obtained by averaging or integrating the first amplitude information obtained from the first received signal and the first amplitude information obtained from the second received signal,
The radar apparatus according to any one of claims 1 to 3, wherein the first target determination section performs target determination using amplitude values averaged or integrated in the calculation processing section. a transmitting step of transmitting signals in at least two or more frequency bands, a first transmission signal in a first frequency band and a second transmission signal in a second frequency band having a frequency band different from the first frequency band;
a receiving step of receiving the first transmission signal and the second transmission signal transmitted by the transmitting step and reflected by one or more objects as a first reception signal and a second reception signal, respectively;
a distance calculation step of calculating distance information from one or more of the objects based on the first received signal and the second received signal;
a speed calculation step of calculating relative speed information with respect to one or more of the objects based on the first received signal and the second received signal;
a selection step of selecting, as first amplitude information, amplitude information corresponding to a specific physical quantity from amplitude information corresponding to the distance information or the relative velocity information;
A target object is detected based on the first amplitude information recorded in a recording unit that respectively records the first amplitude information and the second amplitude information obtained by removing the first amplitude information from the amplitude information. a first target object determination step of performing determination;
a second target determination step of determining the target based on the second amplitude information recorded in the recording unit;
with
The first target determination step combines the first amplitude information obtained from at least the first received signal and the second received signal, and determines the target based on the combined first amplitude information. Object detection method for determination. to the computer,
a transmitting step of transmitting signals in at least two or more frequency bands, a first transmission signal in a first frequency band and a second transmission signal in a second frequency band having a frequency band different from the first frequency band;
a receiving step of receiving the first transmission signal and the second transmission signal transmitted by the transmission step and reflected by one or more objects as a first reception signal and a second reception signal, respectively;
a distance calculation step of calculating distance information from one or more of the objects based on the first received signal and the second received signal;
a speed calculation step of calculating relative speed information with respect to one or more of the objects based on the first received signal and the second received signal;
a selection step of selecting, as first amplitude information, amplitude information corresponding to a specific physical quantity from amplitude information corresponding to the distance information or the relative velocity information;
A target object is detected based on the first amplitude information recorded in a recording unit that respectively records the first amplitude information and the second amplitude information obtained by removing the first amplitude information from the amplitude information. a first target object determination step of performing determination;
A program for executing a second target determination step of determining the target based on the second amplitude information recorded in the recording unit,
The first target determination step combines the first amplitude information obtained from at least the first received signal and the second received signal, and determines the target based on the combined first amplitude information. A program that makes judgments.

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