JPH11352215A - Radar device, and fmcw method for measuring distance and measuring velocity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress interference effects from other radars and to enable the computation of the relative distance to and relative velocity of a target by using the combinations of the results of measurement of the relative distance to and relative velocity of a target at a plurality of modulation rates, detecting the target. SOLUTION: A D/A converter 2 to a FFT processor 12 operate as in conventional cases under the control of a CPU 1A to obtain the beat signal frequency spectrum of up-chirp. A CPU 1A performs detection processing on the beat signal frequency spectrum by a threshold, creates down-chirp transmission waves at a frequency modulation rate Mi, simultaneously obtains the beat signal frequency spectrum of the down- chirp transmission waves, and detects and processes it. Then the relative distance and relative velocity on all the combinations of each of up-chirp and down-chirp detection frequencies, the counter variable Xrv of a two-dimensional table corresponding to each combination is incremented. Next, a variable (i) at the modulation rate Mi in incremented. If the incremented variable (i) is equal to a value N set in advance, targets with relative distance and relative velocity corresponding to the counter variables Xrv of the two-dimensional table with values equal to αN or more are detected.

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 or a ship, and is capable of detecting a target object and measuring its relative distance and relative speed. Equipment and FMCW (Frequency Modu
lated Continuous Wave: Related to a frequency-modulated continuous wave measuring and speed measuring method.

[0002]

2. Description of the Related Art A conventional radar device will be described with reference to the drawings. FIG. 7 is a diagram illustrating the operation principle of a conventional radar device.

When detecting and measuring a target object using a radar on a moving body such as a vehicle or a ship, when a plurality of other radars exist around the own radar, transmission from another radar is performed. Wave interference adversely affects the measurement results.

The effect of this interference will be described with reference to FIG. FIG. 7 shows a case where the own radar and another radar use the same FMCW radar.

The beat signal, which is a measurement signal, includes a target beat frequency Fb based on the transmission wave Ft of the own radar and the reception wave Fr of the own radar, and an interference beat frequency based on the transmission wave Ft of the own radar and the transmission wave Ft ′ of another radar. Two frequency components of Fb ′ are included.

When the speed of light is represented by C, the modulation width is represented by B, and the modulation period is represented by T between the target beat frequency Fb and the relative distance R to the target, the following equation (1) holds. .

Fb = (2B / CT) * R Expression (1)

Here, for example, FFT (Fast Fourier Tra)
nsform), if a frequency of a power spectrum above a certain threshold is detected as a target, as shown in FIG. 7C, the interference beat frequency F
If the average power level of b 'is sufficiently large, there is a problem that the interference beat frequency Fb' is detected as a target and appears as a false image.

Next, another conventional radar apparatus will be described with reference to the drawings. FIG.
FIG. 1 is a block diagram illustrating a configuration of a conventional FMCW radar apparatus disclosed in Japanese Patent Application Publication No. -297124.

In FIG. 8, reference numeral 1 denotes a central control processor (CP).
U), 2 is a digital / analog converter (D / A), 3 is a sawtooth wave generator, 4 is a voltage controlled oscillator (VCO: Voltag)
e Controlled Oscillator), 5 is a directional coupler, 6 is a transmitting antenna, 7 is a receiving antenna, 8 is a mixer, 9 is an amplifier, and 10 is a low-pass filter (LPF).
ter), 11 are analog / digital converters (A / D),
12 is a fast Fourier transformer (FFT: Fast Fourier Tra)
nsform).

Next, the operation of the other conventional radar device described above will be described with reference to the drawings. FIG. 9 is a flowchart showing the operation of another conventional radar device.

From the own radar, the frequency modulation width B (hereinafter, frequency modulation rate Mi = B / Ti) with respect to the modulation period Ti is plotted on the frequency axis of the spectrum obtained from a plurality of different measurement results. C / 2 / Mi respectively
To convert to a power distribution with respect to distance.

As shown in FIGS. 10A to 10C, at this time, the targets R1 to R3 always appear at the same distance, but the false image Rj appears with a different width at different distances due to the difference in Mi.

Correlation (multiplication) of the plurality of distance power distributions
, The component due to the false image is further diffused, the influence thereof is suppressed, the power difference from the target is increased, and as shown in FIG. 11, a threshold value that allows only the target to be detected can be set. .

First, in step ST1 of FIG.
PU1 sets an internal counter variable i to an initial value of 0.

Next, in step ST2, the CPU 1
, The digital / analog converter 2 and the sawtooth wave generator 3 generate a sawtooth wave at the frequency modulation rate Mi, and the voltage controlled oscillator 4 receives the voltage and generates and outputs a transmission wave. This transmission wave is input to the directional coupler 5, a part of which is input to the transmission antenna 6, and the other is input to the mixer 8.

The transmission wave radiated from the transmission antenna 6 is
The light is reflected by a target existing at a distance R and is received by the receiving antenna 7 as a received wave. The received wave received by the receiving antenna 7 and the transmitted wave from the directional coupler 5 are input to the mixer 8 and become a beat signal having a frequency equal to the frequency difference between the transmitted wave and the received wave. The beat signal is amplified by an amplifier 9, an unnecessary high-frequency component is removed by a low-pass filter 10, and then digitally sampled by an analog / digital converter 11.

Next, in step ST3, the fast Fourier transformer 12 obtains the frequency spectrum of the beat signal from the digital sample data.

Next, in step ST4, the CPU 1
Is converted to a distance axis by multiplying the frequency axis of the frequency spectrum obtained in the previous step ST3 by C / 2 / Mi,
Find the power distribution with respect to distance.

Next, in step ST5, the CPU 1
Increments the value of the internal counter variable i.

Next, in step ST6, the CPU 1
Compares the value of the counter variable i with a preset value M. If it is smaller (i <N), the process returns to step ST2, and if equal (i = N), the process proceeds to the next step ST7.

Next, in step ST7, the CPU 1
Multiplies the power distribution for the N distances obtained in step ST4 by the power for each same distance to obtain one power distribution for the new distance.

Then, in step ST8, the CPU
1 outputs the power distribution with respect to the distance obtained in the previous step ST7, assuming that the target exists at a distance that peaks at power above a certain threshold.

[0024]

In the above-mentioned other conventional radar apparatus, the influence of interference from other radars can be suppressed.

However, in the above-mentioned other conventional radar apparatus, only the modulation (up chirp) for increasing the frequency with time is used for the main purpose of measuring the target distance (hereinafter referred to as ranging). Speed difference between target and own radar (relative speed)
If there is also a purpose to measure the relative velocity, use modulation (down chirp) that lowers the frequency with time in addition to the period of up chirp, as is usually done with known FMCW radar I do.

Then, the following equations (2) and (2) between the beat frequency Fup measured by the up-chirp, the beat frequency Fdn measured by the down-chirp, the target relative distance R, the target relative velocity V and the radar wavelength λ. From the relationship of 3),
The target relative distance R and the target relative speed V are obtained by the calculations of the following equations (4) and (5).

Fup = (2B / CT) * R− (2 / λ) * V (2)

Fdn = − (2B / CT) * R− (2 / λ) * V (3)

R = (CT / 4B) * (Fup−Fdn) Expression (4)

V = − (λ / 4) * (Fup + Fdn) Expression (5)

Here, as can be seen from equation (2) or equation (3), if there is a relative velocity component, it is converted into a distance distribution as performed in the above-mentioned conventional example.
As shown in (1), the target component also behaves such that the distance position changes according to the target relative speed V, and there is a problem that even if the correlation is obtained, the power difference from the false image cannot be increased.

The present invention has been made in order to solve the above-mentioned problems, and has a radar apparatus and an FMCW ranging / measurement apparatus which can reduce the influence of interference from other radars.
The purpose is to obtain a speed measurement method.

[0033]

A radar apparatus according to the present invention is a radar apparatus using the FMCW ranging / velocity measuring method, wherein all of the modulation rate Mi in a set of a modulation frequency rising period and a modulation frequency falling period are set. A combination of the relative distance and the relative speed based on the detection frequency is obtained, a counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented, and the relative distance is calculated at a plurality of modulation rates Mj different from the modulation rate Mi. And the combination of relative speed
One having a central control processor that compares a counter variable on a dimension table with a preset threshold to extract a large counter variable and outputs a target relative distance and relative speed corresponding to the extracted counter variable. It is.

Further, the radar apparatus according to the present invention has the FM
In a radar apparatus using the CW ranging / velocity measuring method, the relative distance is set only when the difference between the half-widths of each spectrum of the modulation rate Mi in a set of the modulation frequency rising period and the modulation frequency falling period is equal to or smaller than a preset value. , A counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented, and the combination of the relative distance and the relative speed at a plurality of modulation factors Mj different from the modulation factor Mi is calculated. A central control processor that compares the counter variable on the two-dimensional table with a preset threshold value, extracts a large counter variable, and outputs a target relative distance and relative speed corresponding to the extracted counter variable. It is provided with.

The FMCW distance measuring and speed measuring method according to the present invention includes a step of obtaining a combination of a relative distance and a relative speed based on all detected frequencies in a set of a modulation frequency rise period and a modulation frequency fall period of a modulation factor Mi. Incrementing a counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed;
obtaining a combination of a relative distance and a relative speed at a plurality of modulation factors Mj different from i; extracting a large counter variable by comparing the counter variable on the two-dimensional table with a preset threshold; And outputting as a target the relative distance and the relative speed corresponding to the set counter variable.

Further, in the FMCW distance measuring / speed measuring method according to the present invention, the difference between the half-widths of each spectrum of the modulation rate Mi between the set of the modulation frequency rising period and the modulation frequency falling period is equal to or less than a preset value. Determining a combination of the relative distance and the relative speed only in the case; incrementing a counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed; and a plurality of modulation ratios Mj different from the modulation ratio Mi. Calculating a combination of the relative distance and the relative speed, extracting a large counter variable by comparing the counter variable on the two-dimensional table with a preset threshold value, and determining a relative distance corresponding to the extracted counter variable. And outputting the relative speed as a target.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A radar device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a radar device according to Embodiment 1 of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1A is a central control processor (C
PU), 2 is a digital / analog converter (D / A), 1
3 is a triangular wave generator, 4 is a voltage controlled oscillator (VCO: Volt
ageControlled Oscillator), 5 is a directional coupler, 6 is a transmitting antenna, 7 is a receiving antenna, 8 is a mixer, 9 is an amplifier, and 10 is a low-pass filter (LPF: Low PassFilt).
er), 11 are analog / digital converters (A / D), 1
2 is a Fast Fourier Transformer (FFT)
form).

Next, the operation of the radar apparatus according to the first embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing the operation of the radar device according to Embodiment 1 of the present invention. FIG. 3 is a diagram showing a two-dimensional table used in the FMCW ranging / speed measurement method of the radar apparatus according to Embodiment 1 of the present invention.

Under the control of the central control processor 1A, the digital / analog converter 2 operates in the same manner as in the above conventional example.
After the triangular wave set by the output voltage of the digital / analog converter 2 is generated by the triangular wave generator 13, the directional coupler 5, the transmitting antenna 6, the receiving antenna 7, the mixer 8, and the amplifier 9 are similar to the above-described conventional example. , LPF 10 and analog / digital converter 11 are operated, and the beat signal is digitally sampled. And the central control processor 1A
Detects a target and performs FMCW distance measurement and speed measurement according to the processing procedure of FIG.

In FIG. 2, first, at steps ST1 to S1
At T3, processing is performed for the up-chirp period, as in the above-described conventional example.

Next, in step ST9, the beat frequency spectrum during the up-chirp obtained in the previous step ST3 is detected as having a target at a frequency UPj which peaks at a power equal to or higher than a certain threshold.

Next, in step ST10, a down-chirp transmission wave is generated and output at the frequency modulation rate Mi, and the beat signal is measured almost simultaneously.

Next, in step ST11, the frequency spectrum of the beat signal during the measured down-chirp period is obtained by fast Fourier transform (FFT) or the like.

Next, in step ST12, the beat frequency spectrum in the down-chirp period obtained in the previous step ST11 is detected as having a target at a frequency DNk which peaks at a power above a certain threshold.

Next, in step ST13, for all combinations of the frequencies detected in the previous steps ST9 and ST12, the relative distance r = R (j, k) is obtained from the above equations (4) and (5). The relative speed v = V (j, k) is obtained.

Next, in step ST14, using the two-dimensional table shown in FIG. 3 including the preset minimum distance unit dR and minimum speed unit dV, the value of (r, v) obtained in the previous step ST13 is obtained. The counter variable Xrv of the minimum distance-speed unit cell corresponding to the combination is incremented.

Next, in step ST5, the value of the counter variable i is incremented in the same manner as in the conventional example, and in the next step ST6, the value of the counter variable i is compared with a preset value N. S
The process returns to T2 and, if equal, proceeds to the next step ST15.

Then, in step ST15, the counter variable Xrv of each cell of the two-dimensional table whose value is equal to or more than αN is extracted, and the target is output assuming that the target of the relative distance r and the relative speed v indicated by the cell exists. I do.

That is, the radar apparatus according to the first embodiment uses a frequency-modulated continuous wave (FMCW) ranging / velocity measuring method, in which a set of modulation frequency rising periods (up-phases) of the modulation factor Mi is obtained. A combination of the relative distance and the relative speed based on all the detection frequencies in the modulation frequency falling period (down phase) is obtained, the counter variable on the two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented, and the modulation rate Mi is calculated. A combination of the relative distance and the relative speed is obtained at a plurality of modulation factors Mj different from
A central control processor (CPU) that compares a counter variable on the two-dimensional table with a preset threshold value, extracts a large counter variable, and outputs a target relative distance and relative speed corresponding to the extracted counter variable. 1A.

In other words, according to the radar apparatus of the first embodiment, in the FMCW ranging / velocity measuring method, the target is detected by using a combination of the measurement results of the relative distance and the relative velocity of the target at a plurality of modulation rates. Therefore, it is possible to measure the relative distance and the relative speed of the target while suppressing the influence of interference from other radars.

Embodiment 2 Embodiment 2 A radar device according to Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 4 is a block diagram showing a configuration of a radar device according to Embodiment 2 of the present invention.

In FIG. 4, 1B is a central control processor (C
PU), 2 is a digital / analog converter (D / A), 1
3 is a triangular wave generator, 4 is a voltage controlled oscillator (VCO: Volt
ageControlled Oscillator), 5 is a directional coupler, 6 is a transmitting antenna, 7 is a receiving antenna, 8 is a mixer, 9 is an amplifier, and 10 is a low-pass filter (LPF: Low PassFilt).
er), 11 are analog / digital converters (A / D), 1
2 is a Fast Fourier Transformer (FFT)
form).

Next, the operation of the radar apparatus according to the second embodiment will be described with reference to the drawings. FIG. 5 is a flowchart showing the operation of the radar apparatus according to Embodiment 2 of the present invention. FIG. 6 is a diagram showing the half-width of the spectrum used in the FMCW ranging / speed measurement method of the radar apparatus according to Embodiment 2 of the present invention.

Under the control of the central control processor 1B, the digital / analog converter 2 operates as in the first embodiment, and the triangular wave set by the output voltage of the digital / analog converter 2 is converted by the triangular wave generator 13. After being generated,
As in the first embodiment, the directional coupler 5, the transmitting antenna 6, the receiving antenna 7, the mixer 8, the amplifier 9, the LPF 1
0, the analog / digital converter 11 operates, and the beat signal is digitally sampled. Then, the central control processor 1B detects the target according to the processing procedure of FIG.
Performs MCW ranging and speed measurement.

In FIG. 5, first, steps ST1 to ST
At T3, the process is performed for the up-chirp period as in the first embodiment.

Next, in step ST16, regarding the beat frequency spectrum during the up-chirp obtained in the previous step ST3, it is detected that a target exists at a frequency UPj that peaks at a power equal to or higher than a certain threshold, and furthermore, For the detection frequency, the spectrum half width Wup shown in FIG. 6 is obtained.

Next, in steps ST10 to ST11, processing is performed for the down-chirp period as in the first embodiment.

Next, in step ST17, the beat frequency spectrum in the down-chirp period obtained in the previous step ST11 is detected as having a target at a frequency DNk that peaks at a power equal to or higher than a certain threshold, and is further detected. Step S for detecting frequency
The spectrum half width Wdn is obtained in the same manner as in T16.

Next, in step ST18, of all the combinations of the frequencies detected in the previous steps ST16 and ST17, only the combinations in which the difference | Wup-Wdn | From the above equations (4) and (5), a relative distance r = R (j, k) and a relative velocity v = V (j, k) are obtained.

Then, step ST14, step ST
5. In steps ST6 and ST15, similarly to the first embodiment, a target is detected using a two-dimensional table, and distance measurement and speed measurement are performed.

In other words, the radar apparatus according to the second embodiment uses a frequency-modulated continuous wave (FMCW) ranging and velocity measurement method in which a set of modulation frequency rising periods (up-phases) of the modulation factor Mi is obtained. A two-dimensional table corresponding to the combination of the relative distance and the relative speed is obtained only when the difference between the half-widths of each spectrum in the modulation frequency falling period (down phase) is equal to or less than a preset value. The above counter variable is incremented, and a plurality of modulation factors M different from the modulation factor Mi are calculated.
j, the combination of the relative distance and the relative speed is obtained, the counter variable on the two-dimensional table is compared with a preset threshold, a large counter variable is extracted, and the relative distance and the relative distance corresponding to the extracted counter variable are extracted. It is provided with a central control processor (CPU) 1B that outputs a speed as a target.

That is, according to the radar apparatus according to the second embodiment, in the FMCW ranging / velocity measuring method, when the measurement results of the relative distance and the relative velocity of the target at a plurality of modulation rates are combined, the spectrum half width is , The effect of interference from other radars is suppressed, and the amount of computation required when measuring the target relative distance and relative speed can be reduced.

[0064]

As described above, the radar apparatus according to the present invention is a radar apparatus using the FMCW ranging / velocity measuring method, in which one set of the modulation rate Mi in the modulation frequency rising period and the modulation frequency falling period is used. The combination of the relative distance and the relative speed based on the detected frequency is calculated, and the counter variable on the two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented. Find the combination of distance and relative speed,
A central control processor that extracts a large counter variable by comparing the counter variable on the two-dimensional table with a preset threshold value and outputs a target relative distance and relative speed corresponding to the extracted counter variable; Therefore, the effect of suppressing the influence of interference from other radars and measuring the relative distance and relative speed of the target is achieved.

Further, as described above, the radar apparatus according to the present invention is a radar apparatus using the FMCW ranging / velocity measuring method, wherein each set of the modulation rate Mi in the modulation frequency rising period and the modulation frequency falling period is set. The combination of the relative distance and the relative speed is obtained only when the difference between the spectral half widths is equal to or less than a preset value, the counter variable on the two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented, and the modulation is performed. A combination of relative distance and relative speed is obtained at a plurality of modulation rates Mj different from the rate Mi, a counter variable on the two-dimensional table is compared with a preset threshold, and a large counter variable is extracted. Equipped with a central control processor that outputs the relative distance and relative speed corresponding to the variables as targets, so that the effects of interference from other radars can be suppressed. An effect that it is possible to reduce the amount of computation required to measure the relative distance and the relative velocity of the target.

As described above, the FMCW distance measuring / velocity measuring method according to the present invention employs a combination of the relative distance and the relative velocity based on all the detected frequencies in one set of the modulation frequency rise period and the modulation frequency fall period of the modulation factor Mi. , A step of incrementing a counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed, and a step of calculating the combination of the relative distance and the relative speed at a plurality of modulation factors Mj different from the modulation factor Mi. Determining, comparing the counter variable on the two-dimensional table with a preset threshold, and extracting a larger counter variable, and outputting as a target a relative distance and a relative speed corresponding to the extracted counter variable. And measure the relative distance and relative speed of the target while suppressing the effects of interference from other radars. An effect that can be.

Further, in the FMCW ranging / speed measuring method according to the present invention, as described above, the difference between each half-width of the spectrum in the modulation frequency rise period and the modulation frequency fall period of the modulation factor Mi is set in advance. Determining a combination of the relative distance and the relative speed only when the value is equal to or less than the calculated value, and incrementing a counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed;
Obtaining a combination of relative distance and relative speed at a plurality of modulation rates Mj different from the modulation rate Mi; and comparing a counter variable on the two-dimensional table with a preset threshold to extract a large counter variable. And outputting as a target a relative distance and a relative speed corresponding to the extracted counter variable, which is necessary when measuring the target relative distance and relative speed by suppressing the influence of interference from other radars. This has the effect of reducing the amount of computational processing required.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a radar device according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart showing an operation of the radar device according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing a two-dimensional table used in the FMCW distance measurement / speed measurement method of the radar device according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a radar device according to Embodiment 2 of the present invention.

FIG. 5 is a flowchart showing an operation of the radar device according to Embodiment 2 of the present invention.

FIG. 6 is a diagram showing a spectrum half width used in the FMCW ranging / speed measurement method of the radar apparatus according to Embodiment 2 of the present invention.

FIG. 7 is a diagram illustrating various signals when the own radar and another radar use the same FMCW radar.

FIG. 8 is a block diagram illustrating a configuration of a conventional radar device.

FIG. 9 is a flowchart showing the operation of a conventional radar device.

FIG. 10 is a diagram showing various signals when the influence of interference can be suppressed in a conventional radar device.

FIG. 11 is a diagram illustrating various signals when the influence of interference can be suppressed in a conventional radar device.

FIG. 12 is a diagram illustrating various signals when the influence of interference cannot be suppressed in a conventional radar device.

[Explanation of symbols]

1A, 1B Central control processor (CPU), 2 digital / analog converter (D / A), 4 voltage controlled oscillator (V
CO), 5-directional coupler, 6 transmitting antenna, 7 receiving antenna, 8 mixer, 9 amplifier, 10 low-pass filter (LPF), 11 analog / digital converter (A / D), 12 fast Fourier converter ( FFT), 1
3 Triangular wave generator.

Claims (4)

[Claims] In a radar apparatus using an FMCW ranging / velocity measuring method, a combination of a relative distance and a relative velocity based on all detected frequencies in a set of a modulation frequency rising period and a modulation frequency falling period of a modulation factor Mi is obtained. , A counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented, and a plurality of modulation rates Mj different from the modulation rate Mi are incremented.
To obtain a combination of the relative distance and the relative speed, compare the counter variable on the two-dimensional table with a preset threshold, and extract a large counter variable, and calculate the relative distance and relative speed corresponding to the extracted counter variable. A radar device comprising a central control processor that outputs a target signal. 2. A radar apparatus using an FMCW ranging / velocity measuring method, wherein a difference between a half value width of each spectrum between a set of modulation frequency rise periods and a modulation frequency fall period of a modulation factor Mi is equal to or less than a preset value. Only in a certain case, a combination of the relative distance and the relative speed is obtained, the counter variable on the two-dimensional table corresponding to the combination of the relative distance and the relative speed is incremented, and the relative distance is calculated at a plurality of modulation rates Mj different from the modulation rate Mi. , A counter variable on the two-dimensional table is compared with a preset threshold value, a large counter variable is extracted, and a relative distance and a relative speed corresponding to the extracted counter variable are output as targets. A radar device comprising a central control processor that performs processing. 3. A step of obtaining a combination of a relative distance and a relative speed based on all the detection frequencies in a set of a modulation frequency rising period and a modulation frequency falling period of the modulation factor Mi, and corresponding to the combination of the relative distance and the relative speed. Incrementing a counter variable on the two-dimensional table; obtaining a combination of relative distance and relative speed at a plurality of modulation factors Mj different from the modulation factor Mi; setting the counter variable on the two-dimensional table in advance Extracting a counter variable larger than the threshold value, and outputting as a target a relative distance and a relative speed corresponding to the extracted counter variable. 4. A step of obtaining a combination of a relative distance and a relative speed only when a difference between each of the half-widths of the spectrum between a set of modulation frequency rise periods and a modulation frequency fall period of the modulation factor Mi is equal to or less than a preset value. Incrementing a counter variable on a two-dimensional table corresponding to the combination of the relative distance and the relative speed; obtaining a combination of the relative distance and the relative speed at a plurality of modulation factors Mj different from the modulation factor Mi; Comparing a counter variable on the two-dimensional table with a preset threshold value to extract a larger counter variable; and outputting a relative distance and a relative speed corresponding to the extracted counter variable as a target. An FMCW ranging / speed measurement method characterized by the following.