JP2000275333A - Radar signal processor by fmicw and distance and speed measuring method by fmicw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a real-time processing operation by reducing the number of times of a frequency analysis and a signal detection. SOLUTION: In a relative distance and speed measurement by an FMICW (frequency-modulation interrupted continuous wave), a plurality of distance bin data are calculated and added (101). Regarding the calculated and added distance bin data, a frequency spectrum is found (16a, 16b). Regarding frequency spectrums which are found respectively regarding an up-phase and a down-phase, the frequency of a spectrum which is detected as a target is found (17a, 17b). Then, frequencies of spectrums at the up-phase and the down-phase are combined by a round-robin system, the combination in which a relative distance is within the range of a prescribed distance bin is searched, and the relative distance which is found by a corresponding combination is output (18). The relative speed of the target is found and output on the basis of the corresponding combination (19).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device mounted on a moving body such as a vehicle, and more particularly to a radar using an FMICW capable of detecting a target object and measuring its relative distance and relative speed. Signal processing device and F
The present invention relates to a distance / speed measurement method using MICW.

[0002]

2. Description of the Related Art A radar mounted on a vehicle or the like has a target distance in the range of several meters to about 200 m, and a single antenna for both transmission and reception makes the device smaller and mounted. Is desirable. As a radar satisfying such requirements, FMICW (Frequency Modulation Interr
upted Continuous Wave) radar.

FIG. 10 is a block diagram showing a basic configuration of a known radar transmitting / receiving apparatus, wherein 1 is a radar transmitting / receiving apparatus, 2 is a control section, 3 is a modulation waveform generating section, and 4 is a VCO (Vol
tage Controlled Oscillator), 5 is the first switch,
6 is a second switch, 7 is an antenna, 8 is a target, 9a,
9b is a distribution circuit, 10 is a phase shift circuit, and 11a and 11b are mixers.

FIG. 11 shows a conventional radar signal processing apparatus for inputting the reception signal and control signal shown in FIG.
Is a radar signal processor, and 13a and 13b are AD (Analog
to Digital) converter, 14 is a memory, 15 is a signal processing controller, 16a and 16b are frequency analyzers, 17a and 17b
Is a signal detection unit, 18 is a combination search unit, and 19 is a speed measurement unit.

FIG. 12 shows the frequency of each signal with respect to time in the FMICW system. Hereinafter, a modulation section in which the frequency increases as time elapses will be referred to as an up-phase, and a modulation section in which the frequency will decrease as time elapses. A section is defined as an up phase, 20a is an up phase VCO signal, 20b is a down phase VCO signal, 21a is an up phase transmission signal, 21b is a down phase transmission signal, 22a is an up phase local signal, and 22b is a down phase. Local signal, 2
3a is an up-phase reception signal, 23b is a down-phase reception signal, 24a is an up-phase beat signal, and 24b is a down-phase beat signal.

FIG. 13 shows the connection terminals of the first switch 5 and the second switch 6 of FIG. 10 with respect to time.

FIG. 14 shows sample data of the up phase and the down phase in the memory 14 of FIG. 11, wherein 25a is an up phase data matrix secured on the memory, and 25b is secured on the memory. Data matrix for down phase,
Other signals are the same as those shown in FIG.

FIG. 15 shows the radar signal processor 12 shown in FIG.
5 is a flowchart showing a signal processing procedure in the latter half of FIG.

FIG. 16 is a diagram showing the input and output of the frequency analyzers 16a and 16b in the radar signal processor 12 of FIG. 11, where 26a to 26c are input signals to the frequency analyzer, and 27a to 27c are frequency analyzers. It is an output signal from the unit.

Hereinafter, a radar of the FMICW system will be described with reference to the drawings. In the FMICW method, as the name implies, a continuous wave subjected to frequency modulation is used intermittently. In FIG. 10, under the control of the control unit 2 in the radar transmitting and receiving apparatus 1, the modulation waveform including the up phase and the down phase generated by the modulation waveform generation unit 3 is input to the VCO 4,
The VCO signal 20 shown in FIG.
Is input to The first switch 5 and the second switch 6 are controlled by the control unit 2 and are connected to the t terminal for a preset time τ as shown in FIG. 13, and to the r terminal for a preset time T−τ as shown in FIG. The operations connected in synchronization with each other are repeated.

First, during the up phase, the VCO signal 20a connected to the t terminal for a time τ becomes the transmission signal 21a shown in FIG. 12 and is input to the antenna 7 via the first switch 5 and the second switch 6. And is radiated from the antenna 7 into the air. Transmission signal 21a radiated into the air
Is illuminated on a target 8 existing at a certain relative distance R and moving at a certain relative speed V, and a part thereof is reflected. The reflected wave has a Doppler frequency component Fv corresponding to the relative velocity V.
The signal is received by the antenna 7 at a time delayed by Kτ = 2R / c (c is the speed of a radio wave) from the transmission signal 21a to become the reception signal 23a of FIG. 12, and is connected to the r terminal by the time T−τ. Distribution circuit 9a via second switch 6
Is input to

The distribution circuit 9a divides the input signal into two and inputs the signal to the mixers 11a and 11b.
On the other hand, the VCO signal 20a that has passed through the first switch 5 connected to the r terminal for the time T−τ is input to the distribution circuit 9b as the local signal 21a in FIG. The distribution circuit 9b divides the input signal into two and inputs the signal to the mixer 11a and the phase shift circuit 10. The phase shift circuit 10 shifts the phase of the input signal by π / 2 radians and outputs the signal to the mixer 11b.

The received signal 23a and the local signal 22a input to each of the mixers 11a and 11b are equal to Kτ within the time T-τ.
The signal is mixed in a period of ~ (K + 1) τ, and becomes a beat signal 24a in which the frequency difference between the received signal 23a and the local signal 22a appears as a frequency. At this time, the mixer 11
a is the real part (I) of the complex signal, and the beat signal 24b by the mixer 11b is the imaginary part of the complex signal.
Since this corresponds to (Q), the beat signal 24a is obtained as a complex signal.

In the down phase period, the beat signal 24b is set in the same manner as in the up phase period.
Is obtained.

At this time, the beat signal 24a Sup (t) in the up phase is expressed by equation (1), and the beat signal 24a Sdn (t) in the down phase is expressed by equation (2).

[0016]

(Equation 1)

The beat signals (I and Q) and the control signal (x) from the control unit 2 are input from the radar transmitting / receiving device 1 to the radar signal processing device 12. The beat signal is sampled by the AD converters 13a and 13b for each τ at the same time as the transmission is started by the control unit 2 and stored in the memory 14. At the time of storage, as shown in FIG. 14 by the signal processing control unit 15, n samples following P1, which is the transmission signal 21a or 21b, for each phase are sequentially (P1, R
1), (P1, R2), (P1, R3),..., (P1, Rn). P2 which is the transmission signal 21a or 21b
The same applies to (P2, R1), (P2, R2), (P2, R
3),..., (P2, Rn), and generate data matrices 25a and 25b for each phase. Here, Rk (k = 1 to n) includes a target signal at a relative distance in the range shown by Expression (5).
Is the k-th distance bin.

[0018]

(Equation 2)

The signal processing control unit 15 determines the time at which the sampling for Pm is completed based on the control signal x from the control unit 2 and proceeds with the subsequent signal processing. It will be described using FIG.

In the procedure shown in FIG. 15, first, in ST1, the signal processing controller 15 sets its own counter (internal variable) k = 1.

In ST2, the signal processing control unit 15 causes the frequency analysis unit 16a to convert the data P of the k-th distance bin from the up-phase data matrix 25a of FIG.
1 to Pm, and for the data, for example, FFT
(Fast Fourier Transform) or the like, as shown in FIG. 16, obtains a frequency spectrum as an output signal 27 from the input signals P1 to Pm26, and outputs it to the signal detection unit 17a.
In ST3, the signal processing control unit 15 causes the signal detection unit 17a to perform signal detection on the input frequency spectrum using, for example, CFAR (Constant False Alarm Rate) detection, and to detect the frequency U1, U2 of the spectrum detected as a target. ,... Up are obtained and output to the combination search unit 18.

In ST4, the signal processing control section 15 causes the frequency analysis section 16b to convert the data P of the k-th distance bin from the down-phase data matrix 25b of FIG.
1 to Pm, and for the data, for example, FFT
The frequency spectrum is obtained by, for example,
Output to In ST5, the signal processing control unit 15 causes the signal detection unit 17b to perform signal detection on the input frequency spectrum using, for example, CFAR detection, and to detect the frequencies D1 and D1 of the spectra detected as targets.
.., Dq are obtained and output to the combination search unit 18.

Next, in ST6, the signal processing control section 15 causes the combination search section 18 to input the input U1, U2,
, Up and D1, D2,..., Dq are combined in a round robin manner, and a combination Cij (Ui, Dj) in which the relative distance R obtained by Expression (6) falls within the range of Rk shown in Expression (5) is searched. If a combination is found, the process proceeds to ST7, where the relative distance R obtained at the time of the search is output, and the combination Cij (Ui, Dj) is output to the speed measurement unit 19.

[0024]

(Equation 3)

Further, in ST7, the speed measuring section 19 obtains a target relative speed V from the input Cij (Ui, Dj) by using the equation (7) and outputs it.

[0026]

(Equation 4)

Subsequently, in ST8, the signal processing control section 15 adds 1 to the value k of the counter. In ST9, the signal processing control unit 15 compares the value of the counter variable k with n. If the value is smaller, the signal processing control unit 15 causes the frequency analysis unit 16a to perform the process of ST2 again.
If it is larger, it ends.

FIG. 17 shows an example in which three targets 81, 82, and 83 are present. Beat signals 24a1, 24a2, and 24a3 based on three reception signals 23a1, 23a2, and 23a3 for the transmission signal 21a are shown in FIG. Three reception signals 23b1 and 23b for transmission signal 21b
2, 23b3, beat signals 24b1, 24b2, 2
4b3 appears in the second, fifth, and sixth distance bins, respectively. Therefore, a part of a sine wave as each beat signal appears in a series of voltages (measurement data) in the second, fifth, and sixth distance bins, and the frequency analysis unit 16
The detection frequency of each target is obtained by a, 16b and the signal detection units 17a, 17b, and the relative distance R and the relative speed V of each target are measured by the combination search unit 18 and the speed measurement unit 19.

[0029]

In the conventional FMICW-based radar signal processing apparatus configured as described above, frequency analysis and signal processing are performed for all k (k = 1 to n) th distance bins in each phase. Detection must be performed,
There was a problem that processing could not be completed in real time.

The present invention has been made in order to solve the above-mentioned problems. A radar signal processing device using FMICW and a distance signal using FMICW that enable real-time processing by reducing the number of frequency analysis and signal detection processes are provided. The purpose is to obtain a speed measurement method.

[0031]

SUMMARY OF THE INVENTION In view of the above-mentioned object, the present invention provides a frequency-modulated modulated wave signal having an up phase in which the frequency gradually increases and a down phase in which the frequency gradually decreases, at a predetermined measurement period interval. A beat that is a reflected wave at a target of a transmission signal intermittently generated based on the modulation signal and indicates a frequency difference from a reception signal shifted from the transmission signal by a Doppler frequency component corresponding to the target relative speed. Converting means for continuously sampling the signal for a predetermined period after each of the transmission signals to generate a data matrix for each phase comprising the transmission signal and the sampled beat signal; and the up-phase and the down-phase. For each of the above, the sampling of the beat signal which is continuous from the above data matrix as time elapses after the transmission signal Addition means for reading distance bin data that is the same transmission signal and arithmetic addition for the same transmission signal; frequency analysis means for obtaining a frequency spectrum for the arithmetically added distance bin data; and for the up phase and the down phase, And a signal detecting means for obtaining the frequency of the spectrum detected as a target, and searching for a combination in which the relative distance is within a predetermined distance bin range by combining the frequencies of the spectrum in the up-phase and the down-phase in a round robin manner. An FMICW radar signal processing apparatus comprising: a combination search means for outputting a calculated relative distance; and a speed measuring means for obtaining and outputting the target relative speed from the combination.

Further, the present invention is the radar signal processing apparatus by FMICW, wherein the adding means performs the arithmetic addition only in a range not more than a preset distance.

Further, the present invention is the radar signal processing apparatus by FMICW, wherein the adding means performs the arithmetic addition only in a range not less than a predetermined distance.

Further, the present invention resides in a radar signal processing apparatus based on FMICW, wherein the adding means performs arithmetic bin addition on distance bin data having a predetermined distance difference.

According to the present invention, a frequency-modulated modulated wave signal having an up phase in which the frequency gradually increases and a down phase in which the frequency gradually decreases is generated intermittently based on the modulated wave signal at a predetermined measurement period interval. A beat signal indicating a frequency difference between a received signal shifted from the transmission signal by a Doppler frequency component corresponding to the target relative velocity, which is a reflected wave of the target transmission signal, and a predetermined signal after each transmission signal. Generating a data matrix for each phase consisting of the transmission signal and each beat signal sampled continuously for each period; and for the up phase and the down phase, the time after the transmission signal from the data matrix, respectively. Reads distance bin data, which is a sample of successive beat signals as time passes Arithmetically adding for the same transmission signal, obtaining a frequency spectrum for the arithmetically added distance bin data, obtaining the frequency of a spectrum detected as a target for the frequency spectrum for each of the up-phase and the down-phase. And searching for a combination in which the relative distance is within a predetermined range of distance bins by combining the frequencies of the spectrum in the up phase and the down phase in a round robin manner, and outputting the determined relative distance of the corresponding one; Obtaining the relative speed of the target from the combination and outputting the target relative speed.

Further, the present invention provides a distance / speed measuring method by FMICW, wherein the arithmetic addition is performed only in a range equal to or less than a preset distance.

The present invention also provides a distance / speed measuring method by FMICW, wherein the arithmetic addition is performed only in a range not less than a preset distance.

The present invention also provides a distance / speed measuring method by FMICW, wherein the arithmetic addition is performed on distance bin data having a preset distance difference at the time of the arithmetic addition.

[0039]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 shows an FM according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a basic configuration of a radar signal processing device using an ICW. In FIG. 1, reference numeral 101 denotes an added distance data setting unit, 102 denotes a multiple distance data adding unit, and other components are the same as those shown in FIG. FIG. 2 is a flowchart showing the latter half of the signal processing procedure in the radar signal processing device of FIG.

First, the radar transmitting / receiving apparatus shown in FIG. 10 operates in the same manner as the above-mentioned conventional example, and the beat signal (I, Q) and the control signal
(x) is input to the radar signal processing device 12 of FIG. The AD converters 13a and 13b and the memory 14 in FIG. 1 operate in the same manner as in the conventional example, and generate data matrices 25a and 25b for each phase as shown in FIG.

The signal processing control unit 15 determines the time at which the sampling for Pm is completed based on the control signal (x) from the control unit 2 in FIG. 10, and proceeds with the subsequent signal processing. Will be described with reference to FIG.

In the procedure shown in FIG. 2, up to ST1,
Each element operates and performs processing in the same manner as in the above conventional example. Subsequently, in ST101, the signal processing control unit 15 compares the value of the counter k provided therein with a preset value z, and if k> z, proceeds to ST2, and if k ≦ z, proceeds to ST102. .

In ST102, the addition data setting unit 101, which refers to the value of k in the signal processing control unit 15, controls the multi-distance data addition unit 102, and the k-th and k-th data matrices 25a in the up phase as shown in FIG.
The + 1st distance bin data is arithmetically added for the same Pu (u = 1 to m).

In ST103, the addition data setting section 101 referring to the value of k in the signal processing control section 15 controls the multi-distance data addition section 102, and the k-th and k-th data matrices 25b in the down phase as shown in FIG.
The + 1st distance bin data is arithmetically added for the same Pu (u = 1 to m).

At this time, for example, if one target exists at each of the added distances, as shown in FIG. 4, the new beat signal 2a is calculated as the arithmetic sum of the beat signals 24a2 and 24a3.
4a5 is a subsequent processing target.

In ST2, if k> z in ST101, the data P1 to Pm of the up-phase of the k-th distance bin are k-th and k + 1-th distance if k ≦ z. For the up-phase data P1 to Pm arithmetically added to the bins, the frequency analysis unit 1
6a is the frequency spectrum 24 of FIG.
a6 is obtained and output to the signal detection unit 17a. In ST3, the signal detection unit 17a operates in the same manner as in the above-described conventional example, and the frequencies U1, U2,.
p is obtained and output to the combination search unit 18.

In ST4, if k> z in ST101, the data P1 to Pm of the down-phase of the k-th distance bin are k-th and k + 1-th distance if k ≦ z. For the down-phase data P1 to Pm arithmetically added to the bins, the frequency analysis unit 1
6b obtains a frequency spectrum by, for example, FFT, and outputs it to the signal detection unit 17b. In ST5, the signal detection unit 17b operates in the same manner as in the above-described conventional example to obtain the frequencies D1, D2,...

In ST6 and ST7, the combination searching unit 18 and the speed measuring unit 19 operate to output the target distance and speed, as in the above-described conventional example.

In the subsequent ST104, the added distance data setting section 101 compares the value k of the counter of the signal processing control section 15 with a preset value z.
Proceeding to 105, information is provided to the signal processing control unit 15 so as to increment the counter value by two. If k> z, the process proceeds to ST8, and information is given to the signal processing control unit 15 so that the value of the counter is incremented by one.

In ST9, the signal processing control section 15 operates as in the above-described conventional example.

At this time, in the range of k ≦ z, for example, when α targets can exist in each distance bin, the maximum processing amount is z
× {2 × (m-point FFT) + 2 × (m signal detection processes) + (α
X α (combination search processing of m times FFT) + (m times of signal detection processing) + (2α × 2α combination search processing)}. Naturally, m ≧ α and (m-point FFT) + (m signal detection processes)> (2α × 2α combination search process) − (α × α combination search process), so that the processing amount is reduced and real time Processing becomes possible.

When ST101 and ST104 in FIG. 2 are replaced with ST111 and ST112 in FIG. 5, respectively, the range in which arithmetic addition of data is performed in ST102 and ST103 is as shown in FIG. can get.

Embodiment 2 FIG. 7 is a block diagram showing a basic configuration of a radar signal processing apparatus using FMICW according to another embodiment of the present invention. In FIG. 7, reference numeral 201 denotes a second added distance data setting unit, and other components are the same as those shown in FIG. 1 of the first embodiment of the present invention. FIG. 8 is a flowchart showing the latter half of the signal processing procedure in the radar signal processing device of FIG.

First, the radar transmitting / receiving apparatus shown in FIG. 10 operates in the same manner as in the first embodiment of the present invention, and receives the beat signal (I,
Q) and the control signal (x) are input to the radar signal processing device 12 of FIG. The AD converter 13 and the memory 14 in FIG. 7 operate in the same manner as in the first embodiment of the present invention, and the data matrices 25a and 25b for each phase as shown in FIG.
Generate

According to a control signal from the control unit 2 in FIG.
The signal processing control unit 15 determines the time at which the sample for m is completed, and proceeds with the subsequent signal processing. Detailed operations will be described with reference to FIG.

In the procedure shown in FIG. 8, up to ST1,
Each element operates and performs processing in the same manner as in the above conventional example.

Subsequently, in ST201, the signal processing control unit 1
The second added distance data setting unit 201 that refers to the value of k in 5 controls the multiple distance data adding unit 102, and sets the k of the data matrix 25 in the up phase as shown in FIG. Th and k +
The Wth distance bin data is arithmetically added for the same Pu (u = 1 to m).

In ST202, the second added distance data setting section 201 referring to the value of k in the signal processing control section 15
Controls the multi-distance data addition unit 102, and the k-th and k + W-th distance bin data of the data matrix 25 in the down phase as shown in FIG. Arithmetic addition for).

In ST2, the up-phase data Pu obtained by arithmetic addition for the k-th and k + W-th distance bins
(u = 1 to m), the frequency analysis unit 16a
The frequency spectrum is obtained by FT, and the signal
Output to In ST3, the signal detection unit 17a operates in the same manner as in the above-described conventional example, obtains the frequencies U1, U2,..., Up of the spectrum detected as the target and outputs the obtained frequencies to the combination search unit 18.

At ST4, the down-phase data P1 to P1 obtained by arithmetically adding the kth and k + Wth distance bins are calculated.
For Pm, the frequency analysis unit 16b obtains a frequency spectrum by, for example, FFT, and outputs it to the signal detection unit 17b. In ST5, the signal detection unit 17b operates in the same manner as in the above-described conventional example, and the frequency U
, Up, and output to the combination search unit 18.

In ST6 and ST7, the combination searching section 18 and the speed measuring section 19 operate to output the target distance and speed, as in the above-described conventional example. At this time, since the distances of the determination criteria of the combination are Rk and Rk + W, the possibility of finding an incorrect combination with a signal of an adjacent target is low, and a measurement result of a target that should not actually exist can be output. Is less effective.

In ST 203, second added distance data setting section 201 gives information to signal processing control section 15 so that the value of the counter is incremented by two.

In ST9, the signal processing control section 15 operates as in the above-mentioned conventional example.

[0064]

As described above, according to the present invention, the FMI
In signal processing of a radar by CW, a frequency-modulated modulated wave signal having an up phase in which the frequency gradually increases and a down phase in which the frequency gradually decreases, and intermittently generated based on the modulated wave signal at predetermined measurement period intervals. A beat signal indicating a frequency difference between a received signal shifted from the transmission signal by a Doppler frequency component corresponding to the target relative velocity, which is a reflected wave of the target transmission signal, and a predetermined signal after each transmission signal. Each of the periods is continuously sampled, and a data matrix for each phase including the transmission signal and each sampled beat signal is generated, and for the up phase and the down phase, respectively, according to the time lapse after the transmission signal from the data matrix. Reads distance bin data, which is a sample of successive beat signals, and Arithmetic addition is performed on the transmission signal, the frequency spectrum is obtained for the arithmetically added distance bin data, the frequency of the spectrum detected as a target for the up phase and the down phase is further obtained for the up phase and the down phase, and the up phase and The frequency of the spectrum of the down phase is combined in a brute force search for a combination in which the relative distance is within a predetermined distance bin range, and the relative distance obtained for the corresponding one is output, and the relative speed of the target is calculated from the corresponding combination. The number of frequency analysis processing and signal detection processing can be reduced by arithmetically adding the data of the distance bins, the required processing time can be shortened, and real-time processing has been enabled. Radar signal processing device by FMICW and FMICW Separation and speed measurement method can be provided.

Further, the arithmetic addition is performed only in a range equal to or less than a predetermined distance, and the number of frequency analysis processing and signal detection processing is reduced by arithmetically adding data of distance bins. It is possible to provide a radar signal processing apparatus using FMICW and a distance / speed measurement method using FMICW, which are shortened and enable real-time processing.

Also, the arithmetic addition is performed only in a range equal to or greater than a predetermined distance, and the data of the distance bins are arithmetically added to reduce the number of frequency analysis processing and signal detection processing. It is possible to provide a radar signal processing apparatus using FMICW and a distance / speed measurement method using FMICW, which are shortened and enable real-time processing.

Since the arithmetic addition is performed on distance bin data having a predetermined distance difference, data having a large distance difference is added at the time of arithmetic addition. It is possible to provide a radar signal processing device using FMICW and a distance / speed measurement method using FMICW that can reduce the frequency of target output that should be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a radar signal processing apparatus using FMICW according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a signal processing procedure in the radar signal processing device of FIG. 1;

FIG. 3 is a diagram for explaining arithmetic addition of distance bin data of a data matrix in the radar signal processing device of FIG. 1;

FIG. 4 is a waveform chart for explaining signal processing in the radar signal processing device of FIG. 1;

FIG. 5 is a flowchart illustrating a modified example of a signal processing procedure in the radar signal processing device of FIG. 1;

FIG. 6 is a diagram for explaining arithmetic addition of distance bin data of a data matrix in a modification of FIG. 5;

FIG. 7 is a FMICW according to another embodiment of the present invention.
1 is a block diagram showing a basic configuration of a radar signal processing device according to the first embodiment.

8 is a flowchart showing a signal processing procedure in the radar signal processing device of FIG. 7;

9 is a diagram for explaining arithmetic addition of distance bin data of a data matrix in the radar signal processing device of FIG. 7;

FIG. 10 is a block diagram showing a basic configuration of a radar transmitting / receiving apparatus using FMICW.

FIG. 11 is a block diagram showing a basic configuration of a conventional FMICW-based radar signal processing device for inputting a signal from a radar transmitting / receiving device.

FIG. 12 is a diagram showing a change in frequency with respect to time of each signal in the FMICM method.

FIG. 13 is a diagram illustrating the operation of the switch in FIG. 10;

14 is a diagram illustrating sample data of an up phase and a down phase in a memory of the radar signal processing device of FIG. 11;

FIG. 15 is a flowchart illustrating a signal processing procedure in the radar signal processing device of FIG. 11;

16 is a diagram illustrating input and output of a frequency analysis unit of the radar signal processing device of FIG. 11;

FIG. 17 is a diagram for explaining a case where three targets exist.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 radar transmitting / receiving apparatus, 2 control section, 3 modulation waveform generating section, 4 VCO, 5 first switch, 6 second switch, 7 antenna, 8 target, 9a, 9b distribution circuit, 1
0 phase shift circuit, 11a, 11b mixer, 12 radar signal processing device, 13a, 13b AD converter, 14 memory, 15 signal processing control unit, 16a, 16b frequency analysis unit, 17a, 17b signal detection unit, 18 combination search unit , 19 speed measuring unit, 101 additional distance data setting unit, 102 multiple distance data adding unit, 201 second additional distance data setting unit.

Continued on the front page (72) Inventor Shigeki Morita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 5J070 AB17 AC02 AC06 AE01 AF03 AH25 AH31 AH35 AK40 BA01

Claims (8)

[Claims] 1. A frequency-modulated modulated wave signal having an up phase in which the frequency gradually increases and a down phase in which the frequency gradually decreases, and transmission generated intermittently based on the modulated wave signal at predetermined measurement period intervals. A beat signal, which is a reflected wave of a signal at a target and indicates a frequency difference from a received signal shifted from the transmitted signal by a Doppler frequency component corresponding to the relative speed of the target, continuously for a predetermined period after each of the transmitted signals. Conversion means for periodically sampling and generating a data matrix for each phase consisting of the transmission signal and each sampled beat signal; and for the up phase and the down phase, respectively, in accordance with the lapse of time after the transmission signal from the data matrix. Reads distance bin data, which is a sample of successive beat signals, and sends the same transmit signal Addition means for performing arithmetic addition on the signals, frequency analysis means for obtaining a frequency spectrum for the arithmetically added distance bin data, and a signal for obtaining a frequency of a spectrum detected as a target for the frequency spectrum for each of the up phase and the down phase. Combination detecting means for detecting a combination in which the relative distance is within a range of a predetermined distance bin by combining the frequencies of the spectrum in the up phase and the down phase in a round robin manner, and outputting the relative distance obtained for the combination And a speed measuring means for obtaining and outputting the target relative speed from the corresponding combination, and a radar signal processing apparatus by FMICW. 2. An FMICW radar signal processing apparatus according to claim 1, wherein said adding means performs arithmetic addition only within a range of a predetermined distance or less. 3. The radar signal processing apparatus according to claim 1, wherein said adding means performs arithmetic addition only in a range equal to or greater than a predetermined distance. 4. The radar signal processing apparatus according to claim 1, wherein said addition means performs the arithmetic addition on distance bin data having a predetermined distance difference. 5. A frequency-modulated modulated wave signal having an up phase whose frequency gradually increases and a down phase gradually decreasing, and transmission generated intermittently based on the modulated wave signal at predetermined measurement period intervals. A beat signal, which is a reflected wave of a signal at a target and indicates a frequency difference from a received signal shifted from the transmitted signal by a Doppler frequency component corresponding to the relative speed of the target, continuously for a predetermined period after each of the transmitted signals. Generating a data matrix for each phase composed of the transmission signal and each sampled beat signal, and continuously performing the up phase and the down phase in accordance with a lapse of time after the transmission signal from the data matrix, respectively. Read the distance bin data, which is a sample of the beat signal Arithmetically adding the frequency bins; obtaining the frequency spectrum of the arithmetically added distance bin data; obtaining the frequency of the spectrum detected as a target with respect to the frequency spectrum for each of the up phase and the down phase; Searching for a combination in which the relative distance is within the range of a predetermined distance bin by combining the frequencies of the spectrum in the up phase and the down phase in a round robin manner, and outputting the obtained relative distance of the corresponding one; Calculating and outputting the target relative speed; and a distance / speed measurement method using FMICW. 6. The distance / speed measuring method by FMICW according to claim 5, wherein in the step of performing arithmetic addition, the arithmetic addition is performed only within a range equal to or less than a preset distance. 7. The distance / speed measuring method by FMICW according to claim 5, wherein in the step of performing arithmetic addition, the arithmetic addition is performed only in a range not less than a preset distance. 8. The distance / speed measuring method by FMICW according to claim 5, wherein the step of performing arithmetic addition is performed on distance bin data having a preset distance difference when performing arithmetic addition.