JP2000147102A - Fmcw radar apparatus and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FMCW radar apparatus by which a moving object and a stationary object can be recognized precisely, and to provide a recording medium. SOLUTION: In Step 200, the width of a frequency-shift amount is decided. In Step 210, a frequency is shifted. In Step 220, an evaluation value |Vp| is calculated. In Step 230, an adjacent sum Sum 2 is calculated. In Step 240, a spectrum whole sum Sum 1 is calculated. In Step 270, all values of the spectrum whole value Sum 1 are compared, and a true frequency-shift amount Tsn is decided. In Step 280, regarding a spectrum which is frequency-shifted by the true frequency-shift amount, whether the adjacent sum Sum 2 of a spectrum peak is at a threshold value Thp or lower is judged. In Step 290, whether a moving-object estimation flag is set or not is judged. In Step 300, since the adjacent sum Sum 2 is at the threshold value Thp or lower and the moving- object estimation flag is not set, the spectrum peak is judged to be the spectrum peak of a stationary object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FMCW which is used for preventing collision of a moving object, for following a fixed distance, and for detecting the relative speed and distance of a target existing outside the moving object by transmitting and receiving radar waves. The present invention relates to a radar device and a recording medium.

[0002]

2. Description of the Related Art a) Conventionally, in an FMCW radar device, a transmission signal whose frequency is gradually increased and decreased by a triangular modulation signal is transmitted as a radar wave, and a radar wave reflected by a target is received. At the same time, a beat signal is generated by mixing the reception signal with the transmission signal. Then, the frequency of the beat signal (beat frequency) is specified for each section of an ascending portion where the frequency of the transmission signal increases and a descending portion where the frequency decreases using a signal processor or the like. Beat frequency (up beat frequency) fb1 and down beat frequency fb2
Based on (down beat frequency), the distance D to the target and the relative speed V are calculated using the following equations (A) and (B).

V = (C / (4 * f0)) * (fb2-fb1) (A) D = (C / (8 * △ F * fm)) * (fb1 + fb2) (B) where ΔF Is the frequency displacement width (frequency displacement width) of the transmission signal, f0 is the center frequency of the transmission signal, 1 / fm is the time required for one period of modulation (that is, fm is the repetition frequency of a triangular wave), and C is the speed of light.

Therefore, when measurement is performed using the FMCW radar device, for example, a change in the frequency of the transmission signal T and the frequency of the reception signal R shown in FIG. 17 is obtained according to the relationship between the FMCW radar device and the target. Specifically, as shown in FIG. 17A, the moving speed of the moving object to which the radar device is attached is equal to the moving speed of the target reflecting the radar wave (relative speed V =
In the case of 0), the radar wave reflected on the target is delayed by the time required for the round trip to the target, and the graph of the received signal R is obtained by shifting the graph of the transmitted signal T along the time axis. , The up beat frequency fb1 and the down beat frequency f
It is equal to b2 (fb1 = fb2).

On the other hand, as shown in FIG. 17B, when the moving speed with respect to the target is different (relative speed V ≠ 0), the radar wave reflected by the target further has a relative speed V with respect to the target. To receive the corresponding Doppler shift, the graph of the reception signal R is obtained by shifting the graph of the transmission signal T along the frequency axis by the amount of the Doppler shift due to the relative speed V, and the upstream beat frequency fb1 and the downstream beat frequency fb2 (Fb1 ≠ fb2).

Accordingly, the distance D to the target and the relative speed V can be calculated based on the up beat frequency fb1 and the down beat frequency fb2. b) In recent years, as a technique for distinguishing a moving object from a stationary object using the above-described FMCW radar device, a technique described in the following JP-A-7-98375 or JP-A-7-191133 has been proposed. ing.

[0007] This technique uses the physical principle that a stationary object approaches at -VB if the vehicle runs at speed VB. Specifically, for example, assuming that the direction approaching the FMCW radar device is positive, expressing the own vehicle speed by -VB,
Since the speed of the stationary object viewed from the FMCW radar device is VB, the difference between the up beat frequency fb1 and the down beat frequency fb2 is represented by the following equation (C).

(Fb2−fb1) = (4 * VB * f0) / C (C) When this is subjected to frequency analysis by a well-known Fourier transform and displayed as a spectrum, a beat signal of an ascending part including the upbeat beat frequency fb1 is obtained. The spectrum (downbeat signal spectrum) of the falling part including the spectrum (uplink beat signal spectrum) and the downbeat frequency fb2 is shown in FIG.
8 (a).

At this time, if the own vehicle speed VB is known, the down beat signal spectrum is shifted by the frequency of (fb2−fb1) as shown in FIG. Here, when the target to be measured is a stationary object, that is, in the case of a target approaching at the own vehicle speed VB, the spectrum frequencies of the up and down coincide with each other. Whether or not the target is a stationary object can be determined based on the state of coincidence between the spectra of the up beat signal and the down beat signal shown in (b).

[0010]

However, in the above-described technique, if the vehicle speed is simply VB, the stationary object is -V.
Due to the principle of approaching at B, the spectrum shift amount (frequency shift amount) is limited to a range calculated from VB, etc., and as described below, accuracy in distinguishing a moving object from a stationary object is improved. There was a problem of chipping.

Due to the response delay and error of the vehicle speed sensor,
An accurate frequency shift amount cannot be calculated. That is, the frequency shift amount can be basically obtained from the own vehicle speed. However, when the own vehicle speed is calculated by another on-vehicle computer, the actual own vehicle speed is affected by communication delay, filtering effect, and the like. There is a delay from the speed, and there is also an error in the sensor itself. Therefore, if the frequency shift amount is simply calculated from the own vehicle speed, the frequency shift amount is not accurate, and as a result, an incorrect determination is made.

Since the direction of the radar beam is not taken into account, an accurate frequency shift amount cannot be determined. Radar, beam steer,
In the scan beam sensor, a deviation occurs between the (apparent) moving direction of the stationary object and the beam direction in which the relative velocity can be detected by the Doppler effect. This effect becomes more remarkable as the radar detects a wide range (with a large beam steering angle).

In the spectrum comparison after the shift,
Since only the amplitude information is to be evaluated, an incorrect match determination is made. When comparing spectra,
Conventionally, only amplitude information such as the peak level and shape of a spectral peak (which is a large power spectrum having a peak corresponding to the target) is used. Occurs. That is, since the spectrum peak from the moving object is recognized as that from the stationary object and separated and removed, the recognition of the moving object, which is the original purpose, is not correctly performed.

When spectral peaks from a stationary object and a moving object overlap, the spectral peak of the moving object may be erased. For example, when the FMCW radar is used as an on-vehicle radar, a stationary object such as a roadside object such as a guardrail and a moving object that is a vehicle traveling ahead appear in the spectrum. In such a case, depending on the relationship between the vehicle speed and the distance to the stationary object, the distance to the moving object, the relative speed, and the like, the spectral peaks of the stationary object and the moving object may still be synthesized.

Particularly, in the case of a stationary object having a large reflection level, such as a tunnel entrance, the peak level is large and the frequency spread near the peak is large, so that the spectral peak of the moving object may be buried or overlapped. At that time, it may be observed as if it were one spectrum peak.

In this case, if the spectrum is simply subtracted as in the above-described known technique, the spectrum peak is also subtracted from the moving object, and the radar cannot function normally. The present invention has been made to solve the above problems, and has as its object to provide an FMCW radar device that can accurately recognize a moving object and a stationary object.

[0017]

(1) According to the first aspect of the present invention, the transmitting means generates a transmission signal whose frequency is gradually increased and decreased by, for example, frequency modulation by a triangular wave modulation signal.
Transmit as a radar wave, receiving means receives the radar wave reflected by the target, generates a received signal,
The received signal is mixed with the transmitted signal to generate a beat signal.

[0018] Then, the spectrum creating means, for example, as shown in Fig. 7, can correspond to a plurality of targets from the up-beat signal at the time of up-modulation in which the frequency of the transmission signal rises by, for example, well-known Fourier transform. In addition, an uplink spectrum having a spectrum peak (power spectrum) is created, and a downlink spectrum having a plurality of spectrum peaks is similarly created from a downlink beat signal at the time of downlink modulation in which the frequency of a transmission signal decreases.

Next, the detecting means shifts at least one of the spectrum peak of the upstream spectrum and the spectrum peak of the downstream spectrum by a predetermined frequency so that the downstream spectrum coincides with the upstream spectrum, for example.
For example, by moving the frequency shift amount to the left in FIG. 7 and comparing each spectrum peak, the moving state of the target is detected.

In particular, according to the present invention, when the frequency shift amount is set by the plural shift amount setting means on the basis of the speed of the vehicle equipped with the FMCW radar device, a plurality of frequency shift amounts are set in consideration of measurement errors. Set. For example, in the related art, the frequency shift amount (fb2−fb1) is set based on the following equation (C). However, in the present invention, not only a single frequency shift amount but also a basic frequency shift amount is used. Another frequency shift amount is set within a predetermined range on both sides of the amount.

(Fb2−fb1) = (4 * VB * f0) / C (C) Next, the evaluation means determines the degree of coincidence between the two spectra for each of the uplink spectrum and the downlink spectrum corresponding to each frequency shift amount. The spectrum matching degree shown is evaluated. Here, when there are many spectral peaks, the degree of coincidence between the spectral peaks is checked, and the overall evaluation is performed to evaluate the degree of spectral matching between the two spectra. If there is only one pair of spectrum peaks, the degree of matching of the two spectra may be evaluated based on the degree of matching between the pair of spectrum peaks.

For example, the downlink spectrum is shifted by a certain frequency shift amount, and in this state, how much each spectrum peak of the uplink spectrum matches each spectrum peak of the downlink spectrum, for example, in terms of amplitude and phase (spectrum matching degree) ) Can be evaluated, for example, using the total spectrum sum Sum1 obtained by summing the sum Sum2 of the evaluation values | Vp | described later.

Then, based on the evaluation result, the determination means determines that the frequency shift amount having the highest degree of spectrum matching is a true frequency shift amount that is less affected by errors in the vehicle speed sensor and the like. In other words, it is considered that the larger the difference between each spectrum peak of the upstream spectrum and each spectrum peak of the downstream spectrum is, the greater the effect of various errors is. Therefore, here, the frequency shift amount (for example, spectrum Sum Sum
(1 is the smallest) is selected as having less influence of the error.

Next, with respect to the up spectrum and the down spectrum corresponding to the true frequency shift amount, the target corresponding to each spectrum peak is determined by the stationary determination means (for example, using a sum Sum2 described later). Is determined, and a stationary object is detected (for example, when the neighborhood sum Sum2 is equal to or less than a predetermined value Thp, the stationary object is determined).

As described above, in the present invention, a plurality of frequency shift amounts are set, and a true frequency shift amount is obtained from the plurality of frequency shift amounts.
The stillness of the target is determined using the spectrum corresponding to the true frequency shift amount. In other words, if the vehicle speed is calculated by another on-board computer, the communication delay,
Due to the effect of the filtering, a delay from the actual vehicle speed occurs, and the vehicle speed sensor itself has an error. Therefore, as in the present invention, the frequency shift amount is given a width in advance, and the optimal frequency shift amount is determined from the range. By selecting and using, it is possible to accurately determine a stationary object from among many targets by excluding an error of a vehicle speed sensor or the like.

(2) The invention of claim 2 exemplifies the invention of claim 1, in which a basic frequency shift amount and a frequency shift amount deviated therefrom by a predetermined amount are set. For example, as shown in the following formula (D), in the present invention, not only a single frequency shift amount but also another frequency shift amount is set within a predetermined range (± ｖDv) on both sides of the basic frequency shift amount. ing.

(Fb2−fb1) = (4 * (VB ± Dv) * f0) / C (D) Therefore, it can be considered that a true frequency shift exists in these frequency shifts. According to the above-described evaluation, the true frequency shift amount can be determined.

(3) According to the third aspect of the present invention, the degree of spectral matching of each spectrum peak is evaluated by, for example, a sum Sum2 described later, and a total sum Sum1 of the spectrum described later obtained by summing the sum Sum2 of each spectrum peak, for example. , The degree of spectrum matching for each frequency shift amount can be evaluated.

Therefore, for example, the total spectrum sum Sum1
Can be regarded as a true frequency shift amount. (4) In the invention of claim 4, for each spectrum peak,
For example, the degree of spectral matching is evaluated by the neighborhood sum Sum2, and based on the evaluation, "for example, the neighborhood sum Sum
If the value of 2 is lower than a predetermined threshold, the object is determined to be a stationary object. "

If the degree of spectrum matching of each spectrum peak exceeds a predetermined threshold, as shown by Sn in FIG. 8, for example, it can be determined that the object is a moving object.
Therefore, for example, it is possible to determine a stationary object from targets having a spectral matching degree equal to or less than the threshold value. When the possibility of the synthesized peak is low, it is possible to determine that the target whose spectral match degree is equal to or less than the threshold value is a stationary object.

(5) According to the fifth aspect of the invention, the evaluation of the degree of spectrum matching is performed based on information in a frequency band having a predetermined width of a spectrum peak. As a result, more accurate evaluation can be performed, and as a result, an accurate determination of the true frequency shift amount and a stationary object determination can be performed.

(6) According to the invention of claim 6, since the spectrum matching degree is evaluated based not only on the amplitude of the power spectrum but also on the azimuth information of the target, more accurate evaluation can be performed. For example, when there is a spectrum peak of the same level by chance in both the upstream and downstream spectra, accurate stationary object determination may not be performed.

However, for example, when a phase difference monopulse radar having two reception antennas is used, the azimuth information from the target is indicated by the phase difference between the two systems, and the phase difference is determined between the upstream part and the downstream part. And have the same value with a different sign, and this can be used to evaluate the degree of spectrum matching.

(7) The invention of claim 7 exemplifies a spectrum evaluation method. For example, as shown in FIG.
The amplitude evaluation value based on the amplitude of the spectrum peak is Y,
Since the absolute value (for example, | Vp |) of the evaluation vector with the phase evaluation value based on the azimuth information of the target as X is calculated, and the spectrum matching degree is evaluated using the absolute value, the stationary object determination is more accurately performed. It can be performed.

The amplitude evaluation value can be obtained from the following equation (E), and the phase difference evaluation value can be obtained from the following equation (F). Amplitude evaluation value = | (Rise peak amplitude−Descent peak amplitude) / Rise peak amplitude | (E) Phase difference evaluation value = | Rise phase difference + Descent phase difference | (F) Also, the spectrum peak is complex. When expressed as a vector, the amplitude of the spectrum peak is indicated by the absolute value (length) of the complex vector, and the phase is indicated by the rotation angle. Therefore, the evaluation vector is obtained from this complex vector and the absolute value is calculated. May be.

(8) The invention of claim 8 exemplifies a technique for determining a true frequency shift amount. First, for example, using the following equation (G), the neighborhood sum of the absolute value of the evaluation vector for each spectrum peak is obtained. Here, the reason why the neighborhood sum is used is that the evaluation accuracy is higher when the evaluation is performed including the frequency in the vicinity thereof than when the evaluation is performed only at one point of each spectrum peak.

The neighborhood sum Sum2 = | Vp (pn) | + | Vp (p-n + 1) | + ... + | Vp (p) | + ... + | Vp (p + n) | ... (G) P; Peak frequency number (indicating the peak number),
n; width of neighborhood Next, after calculating the sum Sum2 of the vicinity of each of the peaks, the sum Sum2 of each neighborhood is obtained, for example, as in the following equation (H)
To obtain the total spectrum sum S for each frequency shift amount.
Find um1.

The total sum of the spectrum Sum1 = ΣNearest sum Sum2 (H) Then, for example, the total sum of each spectrum Su of this evaluation value is calculated.
Of m1 (| Vp |), the frequency shift amount having the smallest value can be determined as the true frequency shift amount TSn. That is, the smaller the total spectrum sum Sum1, the smaller the absolute value of each evaluation vector as a whole,
Therefore, the degree of coincidence of each spectrum peak is considered to be large.

(9) According to the ninth aspect of the present invention, after the true frequency shift amount is determined, in the up spectrum and the down spectrum corresponding to the true frequency shift amount, for each pair of spectral peaks, This is an example of whether to perform the stationary object determination of the target.

Here, the neighborhood sum of the absolute values of a certain evaluation vector is compared with a predetermined threshold value. If the neighborhood sum is equal to or smaller than the threshold value, the amplitude evaluation value is small and the phase difference evaluation value is small. , It is considered that the target is a stationary object.

(10) In the tenth aspect, the direction of the beam is considered. That is, when the beam of the radar is directed in a direction other than the traveling direction of the vehicle, a deviation occurs between the moving direction of the stationary object and the beam direction in which the relative speed can be detected by the Doppler effect, and an error occurs in the determination of the stationary object.

Therefore, in the present invention, since the frequency shift amount is set in consideration of the direction of the beam, a still object can be determined more accurately. For example, if the direction of the beam is shifted to the side by θ from the traveling direction of the vehicle,
The relative velocity of the target measured by this beam is cosθ
The multiplied value can be regarded as the relative speed of the true target.

(11) In the eleventh aspect, a moving object is considered. When the FMCW radar is used as an on-vehicle radar, a stationary object such as a roadside object such as a guardrail and a moving object that is a vehicle traveling ahead appear in the spectrum,
Depending on the relationship between the vehicle and the stationary object, the spectral peaks of the stationary object and the moving object may be combined, and the stationary object may not be accurately determined.

Therefore, according to the present invention, for a target which has already been recognized as a moving object, the current moving position is predicted and a moving object prediction flag is set. If the object prediction flag is set, it is regarded as a synthesized spectrum peak,
The spectral peak is not determined to be a stationary object.

As a result, even when traveling in an urban area where there are many roadside objects, a combined peak obtained by combining a moving object peak and a stationary object peak is not recognized as a stationary object, and a more accurate stationary object determination can be performed. It becomes possible. (12) The twelfth aspect of the present invention is the same as the first aspect of the present invention with respect to the basic configuration which is the premise of the FMCW radar apparatus. The frequency shift amount is set in consideration of the direction. As a result, the stationary object can be determined more accurately.

That is, as shown in FIG. 5, if there is a deviation between the traveling direction of the vehicle and a stationary object (roadside object), a deviation occurs in the precise relative speed between the vehicle and the stationary object. Has an effect on the calculation of the frequency shift amount. Here, the influence is reduced by taking the beam direction into account.

(13) The thirteenth aspect of the invention has the same function and effect as the fourth aspect of the invention. (14) The invention of claim 14 has the same effect as the invention of claim 5. (15) The invention of claim 15 has the same operation and effect as the invention of claim 6. (16) The invention of claim 16 has the same effect as the invention of claim 7.

(17) The seventeenth invention has the same function and effect as the ninth invention. (18) The invention of claim 18 has the same effect as the invention of claim 11. (19) The invention of claim 19 is the same as the invention of claim 1 with respect to the basic configuration that is the premise of the FMCW radar apparatus. In this case, in particular, the amplitude of the spectrum peak and the azimuth information of the target are described. Since the degree of spectrum matching of each spectrum peak is evaluated using the above method, the stationary object can be determined more accurately.

(20) The twentieth aspect of the invention has the same function and effect as the fifth aspect of the invention. (21) The invention of claim 21 has the same effect as the invention of claim 7. (22) The invention of claim 22 has the same operation and effect as the invention of claim 9. (23) The invention of claim 23 has the same operation and effect as the invention of claim 11.

(24) The twenty-fourth aspect of the present invention is the same as the first aspect of the present invention in terms of the basic configuration on which the FMCW radar device is based, and here, in particular, by using a moving object prediction flag, Still object determination can be performed more accurately. In other words, in the present invention, a moving object prediction flag is set by predicting the current moving position for a target that has already been recognized as a moving object, and the moving object prediction flag is set for the current determination target spectrum peak. Is set, it is regarded as a synthesized spectrum peak, and the spectrum peak is not determined to be a stationary object.

Thus, even when traveling in an urban area where there are many roadside objects, a combined peak obtained by combining a moving object peak and a stationary object peak is not recognized as a stationary object, and a more accurate stationary object determination can be made. It becomes possible. (25) In the invention of claim 25, peak information is used.

Here, the peak information related to the peak of the spectrum peak includes the peak frequency at which the amplitude of the spectrum peak is maximum, the amplitude (peak level) at the peak frequency, and the phase difference (of a corresponding pair of spectrum peaks) at the peak frequency. And so on.

In the present invention, when evaluating the degree of spectrum matching between a pair of corresponding spectrum peaks in the upstream spectrum and the downstream spectrum, for example, one peak information indicating the top of the spectrum peak of the upstream spectrum and the downstream spectrum The peak information of one point indicating the peak of the corresponding spectrum peak is used.

In this case, the amount of information to be processed is small, so that the processing speed is higher than in the case of processing the spectrum waveform in the up spectrum and the down spectrum. Further, since a large-capacity memory is unnecessary, the cost can be reduced. Further, when the frequency analysis is performed by a processor different from the recognition processing, it may not be possible to transmit all the waveform data due to the communication speed. Information can be transmitted reliably.

(26) According to the twenty-sixth aspect, similarly to the twenty-fifth aspect, the peak information is used for evaluating the degree of spectrum matching. Here, in particular, based on the peak information of the spectrum peaks of both spectra existing within a predetermined width from the peak frequency of the spectrum peak in one of the reference spectra (for example, the upstream spectrum),
Evaluate the degree of spectrum matching.

For example, with reference to the peak frequency of a predetermined spectrum peak of the upstream spectrum, it is checked whether or not the peak of the corresponding spectrum peak of the downstream spectrum is within a predetermined width. Then, when the peak of the spectrum peak of the downstream spectrum exists within the predetermined width, it is evaluated that the degree of spectrum matching is high (for example, by minimizing the absolute value of the evaluation vector). Therefore, a target evaluated as having a high degree of spectrum matching can be determined as a stationary object.

Thus, even when the respective spectral peaks of both spectra do not completely match, the degree of spectral matching can be evaluated, and the practicability is high.
Further, according to the present invention, as in the case of the twenty-fifth aspect, since the amount of information to be handled is small, there is a similar advantage regarding information processing.

(27) In the invention of the twenty-seventh aspect, similarly to the invention of the twenty-fifth aspect, the peak information is used for the evaluation of the degree of spectrum matching. Here, the spectrum peak of one spectrum (for example, an up spectrum) serving as a reference is shifted from the spectrum peak of the other spectrum (for example, a down spectrum) within the range of the frequency shift amount ± a predetermined width. And if you shift to this range,
The spectrum matching degree is evaluated based on the peak information of the peaks of the spectrum peaks of both spectra. In the present invention, in particular, for example, instead of uniformly shifting the entire downlink spectrum, each spectrum peak of the downlink spectrum is individually shifted by a frequency shift amount ± a predetermined width. The present invention has a slightly different method from the invention of claim 26, but has the same effect.

(28) The invention of claim 28 exemplifies peak information. (29) The invention of claim 29 has the same operation and effect as the invention of claim 7. (30) The invention of claim 30 has the same operation and effect as the invention of claim 9. (31) The invention of claim 31 shows a recording medium.

Examples of the recording medium include various recording media such as an electronic control unit configured as a microcomputer, a microchip, a floppy disk, a hard disk, and an optical disk. That is, there is no particular limitation as long as it stores means such as a program that can execute the above-described processing of the FMCW radar device.

[0061]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment (embodiment) of an FMCW radar apparatus according to the present invention will be described below with reference to the drawings. First Embodiment a) FIG. 1 is a block diagram illustrating an entire configuration of an FMCW radar apparatus (hereinafter simply referred to as a radar apparatus) for obstacle detection according to an embodiment to which the present invention is applied. The radar device according to the present embodiment is a so-called phase difference monopulse radar device.

As shown in FIG. 1, a radar device 2 of the present embodiment transmits a radar wave modulated to a predetermined frequency in accordance with a modulation signal Sm. A transmitting / receiving unit 10 comprising a pair of receivers 14 and 16 for receiving the reflected radar wave, and a modulation signal Sm to the transmitter 12 and an intermediate frequency beat signal B1 output from the receivers 14 and 16 , B2, and a signal processing unit 20 that executes a process for detecting an obstacle and determining a stationary object.

Here, the transmitter 12 is the transmitting means of the present invention,
The receivers 14 and 16 correspond to receiving means, and the signal processing unit 20 corresponds to other means (spectrum creating means, detecting means, and the like). In the present embodiment, the transmitting / receiving unit 10 is mounted on the front of the vehicle so that the radar device 2 detects an obstacle in front of the vehicle, and the signal processing unit 20 is located at a predetermined position in the vehicle interior or in the vicinity of the vehicle interior. Installed.

Here, first, the transmitter 12 transmits a voltage-controlled oscillator (VCO) 12b for generating a high-frequency signal in the millimeter wave band as a transmission signal and a modulated signal Sm to the voltage-controlled oscillator 1
A modulator (MOD) 12a for converting the voltage to an adjustment level of 2b and supplying the adjusted level to the voltage controlled oscillator 12b;
b, a power splitter (COU) that splits the power of the transmission signal from the receiver b and generates a local signal to be supplied to each of the receivers 14, 16.
P) 12c and 12d, and a transmission antenna 12e that emits a radar wave according to a transmission signal.

The receiver 14 receives a radar wave, a mixer 14b for mixing a received signal from the antenna 14a with a local signal from the power divider 12d, and amplifies the output of the mixer 14b. A preamplifier 14c and a low-pass filter 1 for removing unnecessary high-frequency components from the output of the preamplifier 14c and extracting a beat signal B1, which is a difference component between the frequencies of the transmission signal and the reception signal.
4d, and a post-amplifier 14e that amplifies the beat signal B1 to a required signal level.

The receiver 16 has exactly the same configuration as the receiver 14 (14a to 14e correspond to 16a to 16e), receives a local signal from the power distributor 12c, and converts the beat signal B2. Output. And the receiver 14
To the receiving channel CH1 and the receiver 16 to the receiving channel CH
Call it 2.

On the other hand, the signal processing section 20 is activated by the activation signal C1, and is activated by the activation signal C2 and the triangular wave generator 22 for generating the triangular modulation signal Sm. The beat signal B1 from the receivers 14 and 16 is activated. , B2 to A / D converters 24a, 24b for converting the data into digital data D1, D2.
And the CPU 26a, the ROM 26b, and the RAM 26c. The start signals C1 and C2 are transmitted to operate the triangular wave generator 22 and the A / D converters 24a and 24b.
At the same time, based on the digital data D1 and D2 obtained through the A / D converters 24a and 24b, the distance to the obstacle, the relative speed, and the direction of the obstacle are detected, and the obstacle for determining the stationary object is detected. The microcomputer 26 includes a well-known microcomputer 26 that executes an object detection process (described later), and an arithmetic processing device 28 that executes a fast Fourier transform (FFT) operation based on an instruction from the microcomputer 26.

When the A / D converters 24a and 24b start operating in response to the start signal C2, the A / D converters 24a and 24b A / D convert the beat signals B1 and B2 at predetermined time intervals, and the RAM 26c
When the A / D conversion is completed a predetermined number of times while writing in a predetermined area, an end flag (not shown) set on the RAM 26c is set, and the operation is stopped.

Then, the triangular wave generator 22 is activated by the activation signal C1, and when the modulation signal Sm is input to the voltage controlled oscillator 12b via the modulator 12a, the voltage controlled oscillator 12b outputs the triangular waveform of the modulated signal Sm. The frequency increases at a predetermined rate in accordance with the rising gradient of the waveform (hereinafter, this section is referred to as a rising section), and the frequency decreases in accordance with the subsequent descending gradient (hereinafter, this section is referred to as a falling section). A transmission signal modulated as described above is output.

FIG. 2 is an explanatory diagram showing a modulation state of a transmission signal. As shown in FIG. 2, the frequency of the transmission signal is modulated by the modulation signal Sm so as to increase or decrease by ΔF during a period of 1 / fm, and the center frequency of the change is f0. The reason why the frequency is modulated at intervals of 100 ms is that an obstacle detection process described later is executed at a cycle of 100 ms, and the activation signal C1 is generated during the process.

The radar wave corresponding to the transmission signal is transmitted from the transmitter 1
2 and reflected by the obstacles are received by the receivers 14 and 16. And receivers 14, 16
Here, beat signals B1 and B2 are generated by mixing the reception signals output from the reception antennas 14a and 16a and the transmission signal from the transmitter 12. Note that the received signal is delayed with respect to the transmitted signal by the time that the radar wave travels back and forth to the obstacle, and if there is a relative speed between the radar signal and the obstacle, the received signal is subjected to a Doppler shift according to the relative speed. . Therefore, the beat signals B1 and B2 include the delay component fr and the Doppler component fd (see FIG. 17).
Becomes

As shown in FIG. 3, the digital data D1 obtained by A / D converting the beat signal B1 by the A / D converter 24a is converted into a data block D on the RAM 26c.
B1 and DB2, while the A / D converter 24
Similarly, the digital data D2 obtained by A / D-converting the beat signal B2 with b is converted into data blocks DB3 and DB4.
Is stored in By the way, the A / D converters 24a and 24b
Is activated when the triangular wave generator 22 is activated, and performs a predetermined number of A / D conversions while the modulation signal Sm is being output. Therefore, the data block DB1 in which the first half of the data is stored is stored. , DB3 store rising part data corresponding to the rising part of the transmission signal, and data blocks DB2 and DB4 storing the latter half of the data store falling part data corresponding to the falling part of the transmission signal. Will be.

Thus, each data block DB1 to DB1
The data stored in the DB 4 is the microcomputer 2
6 and the arithmetic processing unit 28, and is used for detecting obstacles and stationary objects. b) Next, the obstacle detection processing executed by the microcomputer 26 will be described with reference to the flowchart of FIG. Note that this obstacle detection processing is started at a period of 100 ms.

As shown in FIG. 4, when this processing is started, first, at step 110, a start signal C1 is output to start the triangular wave generator 22, and at step 120, the termination on the RAM 26c is terminated. Clear the flag and
The activation signal C2 is output to activate the A / D converters 24a and 24b.

As a result, the transmitter 12 which has received the modulation signal Sm from the triangular wave generator 22 transmits the frequency-modulated radar wave and receives the radar wave reflected by the obstacle, thereby receiving the radar wave. , 16 output from the A / D converters 24a, 24a,
24b and converted to digital data D1 and D2
The data is written to the AM 26c.

In the following step 130, it is determined whether or not the A / D conversion has been completed by checking the end flag on the RAM 26c. If the end flag has not been set, it is determined that the A / D conversion has not been completed, and the process repeats step 130 to wait. On the other hand, if the end flag has been set, the A / D conversion has been completed. Is determined to have been completed, and the process proceeds to step 140.

At step 140, one of the data blocks DB1 to DB4 on the RAM 26c is sequentially selected, and the data of the data block DBi (i = 1 to 4) is input to the arithmetic processing unit 28 to perform the FFT operation. Is executed. The data input to the arithmetic processing unit 28 is F
In order to suppress side lobes appearing in the FT operation, a well-known window process using a Hanning window, a triangular window, or the like is performed. Then, a complex vector for each frequency is obtained as the calculation result.

In step 150, based on the absolute value of the complex vector, that is, based on the amplitude of the frequency component indicated by the complex vector, all the frequency components (hereinafter, referred to as peak frequency components) that become the peaks of the peaks (spectral peaks) on the frequency spectrum ) Is detected, the frequency is specified as the peak frequency, and the routine proceeds to step 160. In addition, as a method of detecting the peak of the spectrum peak, for example, the amount of change in amplitude with respect to the frequency is sequentially obtained, and the frequency at which the sign of the amount of change is inverted before and after that is identified as the peak of the spectrum peak. do it.

In step 160, the phase of the peak frequency component specified in step 150 is calculated. This phase is equal to the angle that the complex vector makes with the real axis, and is easily determined from the complex vector. In the following step 170, it is determined whether or not there is an unprocessed data block DBi.
The processing of steps 140 to 160 is executed for the unprocessed data block DBi. If there is no unprocessed data block DBi, the process proceeds to step 175.

In step 175, as described in detail later,
A stationary object determination process is performed to determine whether the detected obstacle is a stationary object. In the following step 180, by comparing the amplitudes of the peak frequency components, that is, the powers, those having the same power in the rising part and the falling part are specified as a pair of the peak frequency components based on the reflected waves from the same obstacle. Execute the pairing process.

However, in this case, in the stationary object determination processing in the step 175, no pairing processing is performed for peaks that are clearly determined to be not a pair. This pairing process is the same as the process shown in, for example, FIG. 7 of Japanese Patent Application No. 8-179227 and its description, and therefore, detailed description thereof will be omitted.

In the following step 190, step 180
Using the peak frequency components paired in the above, a distance / velocity azimuth calculation process for calculating the distance to the obstacle, the relative speed, and the azimuth of the obstacle is executed, and the process ends. For example, each reception channel CH1,
The phase difference is calculated between the channels CH2. If the signs of the phase differences are not equal, the distance D to the obstacle and the relative speed V are calculated using the following equations (1) and (2).

V = (C / (4 * f0)) * (fb2-fb1) (1) D = (C / (8 * △ F * fm)) * (fb1 + fb2) (2) where ΔF Is the frequency displacement width (frequency displacement width) of the transmission signal, f0 is the center frequency of the transmission signal, 1 / fm is the time required for one period of modulation (that is, fm is the repetition frequency of a triangular wave), C is the speed of light, and fb1 is the rising portion. , Fb2 represents the falling beat frequency (downbeat frequency), and C represents the speed of light.

This distance / velocity / azimuth calculation processing is the same as the processing shown in FIG. 5 of Japanese Patent Application No. 8-179227 and its description, for example, and a detailed description thereof will be omitted. c) Next, the basic principle of the stationary object determination process performed in step 175 will be described.

Here, in order to determine the stationary object, first, a plurality of frequency shift amounts (Sn
-1, Sn, Sn + 1), and the true frequency shift amount TSn is obtained from the evaluation function using the evaluation function. Then, the target corresponding to the peak frequency component is obtained by using the upstream and downstream spectra corresponding to the true frequency shift amount TSn.
Determine whether the object is moving or stationary. This will be described in detail below.

(I) First, the procedure of calculating the frequency shift amount (hereinafter, also simply referred to as shift amount) will be described. First, a basic frequency shift amount calculation formula for calculating a basic frequency shift amount (basic shift amount) is set using the vehicle speed VB or the like.

That is, the equation (1) is modified to calculate a basic amount (basic shift amount = (fb2−fb1)) for determining how much the spectrum is shifted for the determination of a stationary object. Set (3). Basic shift amount = (fb2−fb1) = (4 * VB * f0) / C (3) where fb1 is the up beat frequency, fb2 is the down beat frequency, VB is the vehicle speed, and f0 is the center frequency of the transmission signal. , C
Represents the speed of light.

At this time, if the error of the vehicle speed sensor is known or has been learned, the own vehicle speed VB corrected by a correction coefficient, a map calculation or the like is used. Next, correction according to the beam angle of the laser device 12 is performed. As shown in FIG. 6, assuming that the beam angle from the sensor front direction or the traveling direction in the case of the beam steering and the scan sensor is θ, in the case of a radar that detects the relative velocity using the Doppler effect, the detectable velocity Since the component is a velocity component equal to the beam direction (−VB * COSθ), it is necessary to perform correction. This component decreases as the angle at which the beam is steered and scanned increases, and the true moving speed (approaching speed; -V
The deviation from B) becomes large, and accurate frequency shift cannot be performed.

Accordingly, here, the following equation (4) is set for the first correction in which the angle correction coefficient (COSθ) is added to the basic shift amount. Thus, as θ increases,
The basic shift amount is corrected to be small. Shift amount after first correction = (4 * COS (θ) * VB * f0) / C (4) Next, correction is performed in consideration of the response delay of the vehicle speed sensor.

A vehicle speed sensor generally measures a time interval between pulse signals from a drive system and a wheel system, and detects an actual vehicle speed from the measured value. However, in actuality, since the temporal filtering is performed due to stability, noise, and the like, there is a response delay between the actual vehicle speed and the vehicle speed. For example, 10 per hour
In a situation where the vehicle travels at 0 km, the delay is not a concern, but a time delay of several kilometers per hour occurs during acceleration and deceleration. Therefore, in the present embodiment, processing having an allowable value is performed in consideration of the delay.

More specifically, since the time delay varies depending on the type of the actual vehicle, it is possible to provide each vehicle with a basic delay in advance. This depends on the actual vehicle speed, the time constant of the filter of the vehicle speed sensor, and the like, but is set here as the speed delay value Dv. Therefore, the following equation (5) for the second correction is set using this value.

Second corrected shift amount = (4 * COS (θ) * (VB ± Dv) * f0) / C (5) Here, the resolution of the vehicle speed sensor is considered as the value of the speed delay value Dv. Value. For example, if the vehicle speed sensor is ± 5 km
/ H, an error of Dv = (− 5, 0, +
For example, three settings can be made as in 5).

That is, since the time delay of the vehicle speed sensor may actually occur by the width of the speed delay value Dv, the basic shift amount can be given a certain width by the above equation (5). That is, as will be described in detail later, a plurality of frequency shift amounts are set with a certain width in the frequency shift amount, and the most matched frequency shift amount is selected from among them, so that the frequency shift amount is determined based on the true vehicle speed. The frequency shift amount can be set.

In order to simplify the processing, it is possible to set Dv to a value that absorbs the influence of the angle component. (ii) Next, an evaluation method using an evaluation function will be described.
Here, the spectrum of the descending part is shifted using the plurality of frequency shift amounts obtained by the above equation (5), and the degree of coincidence with the spectrum of the ascending part is compared.

Conventionally, only the peak frequency components of the corresponding spectrum peaks of the uplink and downlink spectra are subtracted using the uniquely determined frequency shift amount. However, in the present embodiment, a plurality of frequency shift amounts are subtracted. The following evaluation function is used to determine the optimal frequency shift amount from (the shift width at the time of shifting).

This evaluation function is calculated by the following equations (6) and (7).
As shown in FIG. 7, not only the amplitude of the spectrum peak but also the phase difference indicating the azimuth information obtained by the phase difference monopulse radar is used. The phase difference is a value obtained by subtracting each phase information received by a monopulse radar having two receiving systems, and a method of obtaining the azimuth of an object using this phase difference is a phase difference monopulse radar. .

Amplitude evaluation value = | (Rise peak amplitude−Descent peak amplitude) / Rise peak amplitude | (6) Phase difference evaluation value = | Rise phase difference + Descent phase difference | (7) In the case of the phase difference monopulse radar, the signs are reversed in the ascending portion and the descending portion due to the configuration, so that if the sum is 0, they match.

Then, as shown in FIG. 6, the length | of the evaluation vector Vp having the amplitude evaluation value Y and the phase difference evaluation value X
Vp | is an evaluation value. Next, this evaluation value | Vp | is obtained for each peak frequency component, and the sum thereof is obtained. In this case, as shown in the following equation (8), not only the target peak frequency component but also Similarly, the evaluation value | Vp | is obtained for the frequencies in the vicinity thereof, and the sum thereof (neighborhood sum Sum2) is obtained. The range in which the neighborhood sum Sum2 is obtained is, as shown in FIG. 8, a band-shaped range sandwiched between left and right broken lines with the dashed line as the center, and varies depending on the resolution of the FFT.

Here, the reason why the neighborhood sum Sum2 is obtained is that the accuracy is higher than when a single peak frequency component is used. Neighborhood Sum2 = | Vp (pn) | + | Vp (p-n + 1) | + ... + | Vp (p) | + ... + | Vp (p + n) | ... (8) where P; ( Peak frequency number, which indicates the order of peaks to be evaluated); n; width of neighborhood (when neighborhood is divided into n) In this case, instead of obtaining the sum of neighborhood for all peak frequency components, Sum2 of the vicinity of only the peak frequency component for determining the moving object
Ask for. This is because if processing is performed on all the data, correct results may not be detected due to peaks such as noise and clutter, and a large amount of calculation time is required.

Here, as shown in FIG. 7, for example, the spectrum peak existing in the rising portion (uplink spectrum) is represented by P
u1, Pu2, Pu3, Pu4, falling part (down spectrum)
Are represented by Pd1, Pd2, Pd
Consider the case of 3, Pd4 (where 1,2,3 are the stationary objects and 4 is the moving object's spectral peak).

In this case, when the downlink spectrum is shifted by a plurality of frequency shift amounts, the result is as shown in FIG. In FIG. 8, the basic shift amount Sn is equal to 3 of Sn ± 1.
The amount of frequency shift was set as a value. The value of ± 1 with respect to the frequency shift amount Sn means a width in consideration of a response delay, an error, and the like of the vehicle speed sensor when calculating the shift amount, and the width of ± 1 is used for convenience of description.

Then, for the upstream and downstream spectrums corresponding to the respective frequency shift amounts, that is, for a pair of spectrum peaks corresponding to both the upstream and downstream spectrums, the vicinity of each peak frequency component is obtained. Sum S
um2 is calculated. Next, the neighborhood sum Sum regarding each of the spectrum peaks
After calculating the sum 2, each neighborhood sum Sum2 is calculated as shown in the following equation (9).
To obtain the total spectrum sum S for each frequency shift amount.
Find um1.

The total spectrum sum Sum1 = Σneighborhood sum Sum2 (9) Then, each spectrum total sum Sum1 (| Vp |)
Is the smallest frequency shift amount and the true frequency shift amount T
Let it be Sn. Therefore, for example, in FIG. 8, the frequency shift amount Sn corresponding to the center spectrum is selected as the true frequency shift amount TSn.

Thus, the total spectrum sum Sum1 (|
Vp |) is considered to be the true frequency shift amount TSn because the absolute value of each evaluation vector is smaller as a whole as the total sum Sum1 of the spectrum is smaller, and therefore, the degree of coincidence of each spectrum peak is larger. Because it can be done.

Here, three types of shift widths have been described as an example. However, actually, the true frequency shift amount is determined based on the width obtained by the above-mentioned equation (3) indicating the second corrected shift amount. TSn is determined. Also, once the true frequency shift amount T
After Sn is obtained, the calculation of the frequency shift amount may be performed in consideration of the true frequency shift amount in the next calculation.

(Iii) Next, a method of separating a moving object and a stationary object using the true frequency shift amount TSn will be described. In the above calculations (i) and (ii), the true frequency shift amount TSn was obtained by excluding the effects of the vehicle speed sensor delay, error, beam direction, and the like. Here, a moving object and a stationary object are determined based on the coincidence of the spectrum shifted by the frequency shift amount.

Conventionally, only the subtraction of the spectrum was performed. However, in the present embodiment, it is considered that there is a possibility that there is a spectrum peak having the same peak level by chance.
That is, the processing is performed in consideration of the case where the peaks of the moving object and the stationary object are combined. Specifically, as shown in FIG. 8 described above, the separation between the moving object and the stationary object is performed by the neighborhood sum S of the evaluation values.
Perform using um2.

That is, as shown in FIG. 8, when the sum Sum2 of the vicinity of a certain spectrum peak is equal to or smaller than the threshold value Thp,
Regarding the amplitude of the spectral peak (peak amplitude) and the azimuth (phase difference) of the beam, it is considered that the ascending and descending spectral peaks match, and the stationary object determination that the coincident spectral peak is a stationary object is made. Do. On the other hand, when the sum Sum2 of a certain spectral peak exceeds the threshold Thp, it is determined that the combination of the spectral peaks of the moving object and the stationary object or the combination of the spectral peaks due to noise or the like, and the stationary object is not determined. Note that the threshold value Thp
May be changed depending on the running state of the vehicle, weather, etc., and is not limited to a fixed value.

(Iv) Next, a description will be given of the determination of the combined peak of the moving object and the stationary object. The determination as to whether or not the peak to be determined is a combination of the spectral peaks of the moving object and the stationary object is performed by using the moving object prediction flag. That is, as shown in FIG. 9, a spectrum peak which was not determined as a stationary object in the previous time and which is determined as a moving object by another means appears after Δt depending on the motion state of the moving object. The position of the likely spectral peak (peak position) is predicted. The flag indicating the predicted position is called a moving object prediction flag. Therefore, even if a stationary object is determined, if the moving object prediction flag is set at the peak position, it is determined that the peak is a combined peak of the moving object and the stationary object, and the stationary object determination is not performed. In the same manner, the moving object prediction flag is sequentially set.

D) Next, the stationary object determination processing in step 175 performed based on the above principle will be described with reference to the flowchart of FIG. This process is a process for determining whether or not the spectrum peak of the obstacle (target) recognized by the radar device 2 corresponds to a stationary object based on the above-described principle.

First, in step 200 of FIG. 10, the second corrected shift amount obtained by correcting the basic shift amount, that is, the width of the frequency shift amount, is calculated based on the equation (5) set in the above procedure. decide. In the following step 210,
(The frequency shift has not been executed yet) For example, the frequency shift is performed from the shift width Sn-1. For example, the entire downstream spectrum is shifted. Therefore, when the present processing is passed for the second time, the frequency shift of the next shift width is performed.

In the following step 220, the aforementioned step 2
10, for a predetermined spectrum peak to be evaluated, an evaluation value | in the vicinity of the peak frequency component at the top of the spectrum peak based on the above equations (6) and (7). Vp | is sequentially calculated.

In the following step 230, the evaluation values | Vp | near the apex of the predetermined spectrum peak calculated in step 220 are summed up based on the above equation (8), and the sum Sum2 of the peak is calculated. calculate. In the following step 240, it is determined whether or not the calculation of the sum Sum2 has been completed for the number of peaks desired to be determined. For example, as shown in FIG. 8, for example, in the shift width Sn-1,
Regarding the four spectral peaks, each of the neighboring sums Sum
It is determined whether or not all 2 have been calculated. If an affirmative determination is made here, the process proceeds to step 250. On the other hand, if a negative determination is made, the process returns to step 220 and thereafter to calculate the evaluation values | Vp | of other spectral peaks and the sum Sum2 of the neighborhood.

In step 250, the above-mentioned step 220 is executed.
The sum Sum of all the spectral peaks at ~ 240
Since the calculation of 2 has been completed, they are summed based on the above equation (9) to calculate the total spectrum sum Sum1. In the following step 260, it is determined whether or not the shift has been performed the shift width times. For example, if the frequency shift amount is Sn-1,
If there are three types, Sn and Sn + 1, it is determined whether or not the above-described calculation of the total sum Sum1 has been performed for each frequency shift amount. If an affirmative determination is made here, the process proceeds to step 270, while if a negative determination is made, the process returns to step 210 and thereafter, and a process of calculating another total sum Sum1 is performed in the same manner as described above.

In step 270, the values of all (for example, three in FIG. 8) total spectrum sums Sum1 are compared.
The frequency shift amount corresponding to the smallest value is defined as a true frequency shift amount TSn. In the following step 280,
Regarding the spectrum that has been frequency-shifted by the true frequency shift amount (the spectrum of the central shift amount Sn in FIG. 8), the sum Sum of the vicinity of a predetermined spectrum peak (specifically, a pair of spectrum peaks corresponding to the upstream and downstream spectra)
It is determined whether or not 2 is equal to or less than the threshold value Thp. If the determination is affirmative, the process proceeds to step 290, and if the determination is negative, the process proceeds to step 320.

In step 320, since the sum Sum2 of the spectrum peaks is larger than the threshold value Thp, that is, since the degree of coincidence of the evaluation is low in determining that the object is a stationary object, the object marker corresponding to the spectrum peak is a moving object. As
A moving object flag indicating that the object is a moving object is set, and the process proceeds to step 330.

On the other hand, in step 290, it is determined whether or not the moving object prediction flag is set at the peak position. If the determination is affirmative, the process proceeds to step 310, and if the determination is negative, the process proceeds to step 300. In step 310, since the moving object prediction flag is set, it is determined that the spectrum peak is a combined peak of a stationary object and a moving object, a combined peak flag indicating a combined peak is set, and the process proceeds to step 330. .

On the other hand, in step 300, since the moving object prediction flag is not set, that is, since the neighborhood sum Sum2 is equal to or less than the threshold value Thp and the moving object prediction flag is set, the spectrum peak is the spectrum peak of the stationary object. When it is determined that there is a stationary object, a stationary object flag indicating a stationary object is set, and the process proceeds to step 330.

In step 330, it is determined whether or not the processing in steps 280 to 310, that is, the processing of determining what the spectral peak means, has been completed for the number of spectral peaks desired to be determined. Here, if a negative determination is made, the processing of step 280 and subsequent steps is repeated, while if an affirmative determination is made, the present processing is ended once.

As described above, in the radar apparatus 2 of the present embodiment, when determining a stationary object, a plurality of frequency shift amounts (Sn-1, Sn, Sn,
Sn + 1), and a true frequency shift amount TSn is obtained from the evaluation function using the evaluation function composed of the equations (6) to (9). Then, using the up spectrum and the down spectrum corresponding to the true frequency shift amount TSn, the spectrum peaks of the two spectrums are evaluated to separate the moving object and the stationary object. Thus, the moving object and the stationary object can be accurately distinguished.

That is, in the present embodiment, the correction is performed in consideration of the beam direction, and further, in consideration of the error due to the vehicle speed sensor and the like, instead of a single frequency shift amount as in the related art,
A plurality of frequency shift amounts are set, and the evaluation value | V
The sum Sum2 and the total spectrum S obtained from p |
By evaluating the frequency shift amount using um1, the true frequency shift amount TSn excluding errors and the like can be determined.

In addition, the upstream and downstream spectrums corresponding to the true frequency shift amount TSn are used, and the sum Sum of each pair of spectral peaks Sum in both spectra is used.
By comparing 2 with the threshold value Thp, a moving object can be excluded, so that it is possible to accurately distinguish whether an individual target is a moving object or a stationary object.

In addition, by using the moving object prediction flag, it is possible to eliminate the combined flag of the moving object and the stationary object. Thereby, it is possible to reliably recognize only the stationary object, and from that point, there is an advantage that the accuracy of the stationary object determination is improved. (Embodiment 2) Next, Embodiment 2 will be described, but description of the same parts as in Embodiment 1 will be omitted.

In the first embodiment, processing such as shifting is performed on the waveform of the spectrum peak (power spectrum), and the stationary object is determined. However, in order to store the spectrum waveforms of the rising part and the falling part, a large-capacity memory for storing the waveform shape in the radar device is required. Further, when the frequency analysis is performed by a processor different from the recognition process, it may not be possible to transmit all the waveform data due to the communication speed.

As a countermeasure, in the present embodiment, the peak information of the spectrum waveform, that is, the peak information on the peak of the spectrum peak (the peak frequency indicating the peak, the amplitude at the peak (peak level), and the peak of the corresponding spectrum peak are shown). Still object determination was performed using only the phase difference (phase difference). The details will be described below.

A) First, the principle of the present embodiment will be described. In the present embodiment, the downlink spectrum is shifted using a plurality of frequency shift amounts obtained by the equation (5) of the first embodiment, and the coincidence between the corresponding spectrum peaks of the uplink spectrum and the downlink spectrum is compared. Here, instead of the waveform information having a predetermined width of each spectrum peak, as shown by the thick line in FIG. 11, the evaluation of the degree of spectrum matching is performed using only the peak information corresponding to the peak of each spectrum peak.

Specifically, first, as in the first embodiment, the length | Vp | of the evaluation vector Vp having the amplitude evaluation value Y and the phase difference evaluation value X is used as the evaluation value. Here, as shown in FIG. 11, spectral peaks present in the upstream spectrum are denoted by Pu1, Pu2, Pu3, Pu4, and spectral peaks present in the downstream spectrum are denoted by Pd1, Pd2, Pd.
3, Pd4 (where 1,2,3 are stationary objects, and 4 is the moving object's spectral peak).

In this case, when the downlink spectrum is shifted by a plurality of frequency shift amounts, the result is as shown in FIG.
In FIG. 12, Sn ± 1 with respect to the basic shift amount Sn.
These three types of frequency shift amounts were used. Then, for the uplink and downlink spectrum corresponding to each frequency shift amount,
That is, the evaluation value | Vp | of the peak information corresponding to the peak of each spectrum peak is calculated for a pair of spectrum peaks corresponding to both the up spectrum and the down spectrum.

Next, after obtaining each evaluation value | Vp |, instead of calculating the neighborhood sum Sum2 as in the first embodiment, each evaluation value | Vp | Is obtained. This evaluation value sum Sum
Vp corresponds to the total sum Sum1 of the spectrum in the first embodiment.

That is, in this embodiment, since the neighborhood sum Sum2 is unnecessary, this evaluation value sum SumVp is equivalent to the total spectrum sum of the first embodiment. Then, the frequency shift amount having the smallest sum of the evaluation values SumVp is defined as a true frequency shift amount TSn. Therefore, in FIG. 12, for example, the frequency shift amount Sn corresponding to the center spectrum is selected as the true frequency shift amount TSn.

Further, separation of a moving object and a stationary object using the true frequency shift amount TSn is performed as follows. FIG.
As shown in FIG. 2, the evaluation value | Vp |
Is equal to or less than the threshold value THp1, it is considered that the spectrum peaks of the up- and down-spectrum coincide with respect to the peak level and the beam direction (phase difference), and the stationary spectral peak is determined to be the stationary object. Make a decision. On the other hand, when the evaluation value | Vp | of a certain spectrum peak exceeds the threshold value THp1, it is determined that the combination of the peaks of the moving object and the stationary object or the combination of the peaks due to noise or the like, and the stationary object is not determined.

B) Next, the stationary object determination process performed based on the above principle will be described with reference to the flowchart of FIG. This process is a process for determining whether or not the spectrum peak of the obstacle (target) recognized by the radar device 2 corresponds to a stationary object based on the above-described principle.

First, in step 400 of FIG. 13, similarly to the first embodiment, the second corrected shift amount obtained by correcting the basic shift amount, that is, the width of the frequency shift amount is determined. In the following step 410, for example, the frequency is shifted sequentially from the shift width Sn-1. In the following step 420, for the predetermined spectrum peak to be evaluated in the spectrum shifted in frequency in step 410, the evaluation value | Vp | is sequentially determined using only the peak information of the peak of the spectrum peak. calculate.

In the following step 440, it is determined whether or not the process of calculating evaluation values | Vp | has been completed for the number of spectral peaks desired to be determined. If the determination is affirmative, the process proceeds to step 450, while if the determination is negative, the process returns to step 420. In the following step 450, the evaluation values | Vp | of the predetermined spectral peaks calculated in the above step 420 are summed up, and the sum SumVp of the evaluation values is calculated.

In the following step 460, it is determined whether or not the shift has been performed the shift width times. If an affirmative determination is made here, the process proceeds to step 470;
Return to 10. In step 470, all evaluation value sums Su
The value of mVp is compared, and the frequency shift amount corresponding to the smallest value is set as the true frequency shift amount TSn.

In the following step 480, regarding the spectrum frequency-shifted by the true frequency shift amount TSn (in FIG. 12, the spectrum of the center shift amount Sn), it is determined whether or not the evaluation value | Vp | of the predetermined peak is equal to or less than the threshold value THp1. Is determined. If an affirmative determination is made here, the process proceeds to step 490, while if a negative determination is made, the process proceeds to step 520.

In step 520, since the evaluation value | Vp | of the spectrum peak is larger than the threshold value THp1, a moving object flag indicating that the object is a moving object is set.
Go to 30. On the other hand, in step 490, it is determined whether or not the moving object prediction flag is set at the position of the spectrum peak. If an affirmative determination is made here, the process proceeds to step 510, while if a negative determination is made, step 500 is performed.
Proceed to.

In step 510, since the moving object prediction flag has been set, the synthetic peak flag indicating the synthetic peak is set, and the flow advances to step 530. On the other hand, in step 500, since the moving object prediction flag is not set, a stationary object flag indicating a stationary object is set, and the process proceeds to step 530.

In step 530, it is determined whether or not processing of all the spectral peaks desired to be determined has been completed.
Here, if a negative determination is made, the process returns to the step 480. On the other hand, if a positive determination is made, the present process is temporarily ended. Like this
In the present embodiment, the stationary object is determined using only the peak information of the peak, instead of using the waveform information (such as near the peak of the spectral peak) as in the first embodiment.

Therefore, there is an effect that the calculation speed is high. Further, a large-capacity memory is not required, and the cost can be reduced. Furthermore, even when the frequency analysis is performed by a processor different from the recognition process, only the peak information needs to be transmitted, and there is an advantage that the transmission speed is hardly affected. (Embodiment 3) Next, Embodiment 3 will be described, but description of the same parts as in Embodiments 1 and 2 will be omitted.

In the second embodiment, the stationary object is determined using only the peak information of the peak of the spectrum peak.
For example, as shown in FIG. 14, in the case of a spectrum having a shape that is not steep, but is gentle and has a wide width, such as a spectrum from a continuous guardrail, the peak of the spectrum peak slightly fluctuates and the rising portion increases. There is a case where the peaks of the spectral peaks do not match (and do not match) at the falling part.

As a countermeasure against this, in the present embodiment, after the frequency shift, a predetermined width P around the peak frequency of the peak of the spectrum peak of the reference uplink spectrum is taken as the center.
The stationary object was determined by setting the peak of the spectrum peak of the downstream spectrum existing within w as the target for calculating the evaluation value | Vp |. The details will be described below.

A) First, the principle of the present embodiment will be described. Specifically, first, similarly to the first embodiment, the evaluation vector Vp having the amplitude evaluation value Y and the phase difference evaluation value X
Is the evaluation value. Here, as shown in FIG. 14, the spectrum peak existing in the upstream spectrum is
Pu1, Pu2, Pu3, Pu4 and the spectral peaks present in the downstream spectrum are represented by Pd1, Pd2, Pd3, Pd4.
(However, it is assumed that 1, 2 and 3 are stationary objects and 4 is a moving object spectral peak).

In this case, when the downlink spectrum is shifted by the basic shift amount Sn, the result is as shown in FIG. Then, an evaluation value | Vp | of the peak information corresponding to the peak of each spectrum peak is calculated for a pair of spectrum peaks corresponding to both the upstream and downstream spectra. It was checked whether or not the peak of the corresponding spectrum peak of the downstream spectrum exists within a predetermined width Pw around the peak frequency of each spectrum peak of the upstream spectrum.
Specifically, paying attention to the peak frequency at the top of a predetermined spectrum peak of the upstream spectrum, an amplitude value in a range of ± Pw / 2 from the peak frequency at a corresponding spectrum peak of the downstream spectrum, and its width Pw Investigate sequentially in small sections. In this case, the peak level, which is the peak information of the apex, is stored, but the amplitude value of the waveform at other positions is “0”.

Therefore, when the peak of the descending A peak corresponding to the peak of the descending A peak exists within the width Pw, such as the peak A, for example, the evaluation value | V
p | is smaller than the evaluation value | Vp | Therefore, here, the evaluation value | Vp |
Find its minimum value. That is, the evaluation value | Vp |
Corresponds to the evaluation value | Vp | of the second embodiment (in an ideal state).

The separation of the moving object and the stationary object is the same as that of the second embodiment except that the stationary object is not determined. b) Next, stationary object determination processing performed based on the above principle will be described with reference to the flowchart in FIG.

First, in step 600 of FIG. 16, similarly to the first and second embodiments, the second corrected shift amount obtained by correcting the basic shift amount, that is, the width of the frequency shift amount is determined. In the following step 610, the frequency is shifted by the basic shift amount Sn. In the following step 620, step 61
In the spectrum frequency-shifted at 0, the above-mentioned evaluation value | Vp | is calculated using the peak information of the top of a predetermined spectrum peak to be evaluated. , The minimum value of the evaluation value | Vp | in the predetermined width Pw is obtained.

In the following step 630, it is determined whether or not the process of calculating the minimum value of evaluation value | Vp | has been completed for the number of spectrum peaks desired to be determined. If the determination is affirmative, the process proceeds to step 640, and if the determination is negative, the process returns to step 620. In step 640, the minimum value of the evaluation value | Vp |
It is determined whether it is 2 or less. If an affirmative determination is made here, the process proceeds to step 650;
Go to 0.

In step 680, since the minimum value of the spectrum peak evaluation value | Vp | is larger than the threshold value THp2, a moving object flag indicating a moving object is set.
Proceed to step 690. On the other hand, in step 650, it is determined whether or not the moving object prediction flag is set at the position of the spectrum peak. If the determination is affirmative, the process proceeds to step 670, while if the determination is negative, the process proceeds to step 660.

In step 670, since the moving object prediction flag has been set, the synthetic peak flag indicating the synthetic peak is set, and the flow advances to step 690. On the other hand, in step 660, since the moving object prediction flag is not set, a stationary object flag indicating a stationary object is set, and the process proceeds to step 690.

At step 690, it is determined whether or not processing of all the spectral peaks desired to be determined has been completed.
Here, if a negative determination is made, the process returns to the step 640, while if an affirmative determination is made, the present process is temporarily ended. Like this
In the present embodiment, the stationary object determination is performed using only the peak information of the peak of the spectrum peak, so that the same effect as that of the second embodiment is obtained.

Further, in this embodiment, it is checked whether or not the peak of the spectrum peak of the rising part has a peak of the spectrum peak of the falling part within the predetermined width Pw.
The minimum value of the evaluation value | Vp | is obtained, and the stationary object determination is performed using the minimum value of the evaluation value | Vp |.

Therefore, there is an advantage that the stationary object can be more reliably determined even when the peak of the spectrum peak may fluctuate, for example, as in the case of a guardrail. In the case where the stationary object determination is not performed, another unit (for example, a process using a pair shift) can be performed to separately perform the stationary object determination. (Embodiment 4) Next, Embodiment 4 will be described, but description of the same parts as in Embodiments 1 to 3 will be omitted.

In this embodiment, basically, the same processing as in the third embodiment is performed. However, since the method for obtaining the minimum value of the evaluation value | Vp | is different, only different points will be described. That is,
Also in the present embodiment, the evaluation value | Vp | of the peak information corresponding to the peak of each spectrum peak is calculated for a pair of spectrum peaks corresponding to both the upstream and downstream spectra. Instead of shifting the entire downstream spectrum at once, the individual spectrum peaks of the downstream spectrum are calculated by the frequency shift amount (for example, Sn) ± P
Shift in the range of w / 2 to evaluate the degree of spectral matching.

Specifically, as shown in FIG. 15B, for example, the C peak in the descending portion is changed from Sn-Pw / 2 to Sn + Pw.
In the case of shifting within the range of / 2, and shifting within that range, processing for obtaining the minimum value of the evaluation value | Vp | in the predetermined width Pw is performed in the same manner as in the third embodiment. The other spectral peaks are similarly shifted to evaluate the degree of spectral matching.

In this embodiment, the same effects as in the third embodiment can be obtained. In addition, the present invention is not limited to the above-described embodiment at all, and does not depart from the technical scope of the present invention.
It goes without saying that the present invention can be implemented in various modes. For example, in the above-described embodiment, the FMCW radar device has been described. However, a recording medium storing a unit for executing control by this device is also within the scope of the present invention.

Examples of the recording medium include various recording media such as an electronic control unit configured as a microcomputer, a microchip, a floppy disk, a hard disk, and an optical disk. That is, F
There is no particular limitation as long as means such as a program that can execute the control of the MCW radar device is stored.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of a radar apparatus according to a first embodiment.

FIG. 2 is a graph showing a change in frequency of a transmission signal.

FIG. 3 is an explanatory diagram showing data stored in a RAM.

FIG. 4 is a flowchart illustrating an obstacle detection process.

FIG. 5 is an explanatory diagram showing correction based on the direction of a beam of a laser radar.

FIG. 6 is an explanatory diagram showing evaluation values.

FIG. 7 is an explanatory diagram showing spectra of a rising part and a falling part.

FIG. 8 is an explanatory diagram showing a spectrum when shifting is performed with three shift widths.

FIG. 9 is an explanatory diagram showing a method of setting a moving object prediction flag.

FIG. 10 is a flowchart illustrating a stationary object determination process according to the first embodiment.

FIG. 11 is an explanatory diagram showing spectra of an ascending portion and a descending portion according to the second embodiment.

FIG. 12 is an explanatory diagram showing a spectrum when shifting is performed with three shift widths.

FIG. 13 is a flowchart illustrating still object determination processing according to the second embodiment.

FIG. 14 is an explanatory diagram showing spectra of an ascending portion and a descending portion according to the third embodiment.

FIG. 15 shows a case where a shift is performed with a basic shift width;
(A) is an explanatory diagram showing a spectrum in Example 3,
(B) is an explanatory view showing a spectrum in Example 4.

FIG. 16 is a flowchart illustrating still object determination processing according to the third embodiment.

FIG. 17 is an explanatory diagram illustrating the principle of an FMCW radar.

FIG. 18 is an explanatory diagram showing a beat signal spectrum by the FMCW radar.

[Explanation of symbols]

2 Radar device 10 Transmitter / receiver 12 Transmitter 12a Modulator 12b Voltage controlled oscillator 12c, 12d Power distributor 12e Transmitting antenna 14, 16 Receiver 14a, 16a Receiving antenna 14b, 16b Mixer 14c , 16c: preamplifier 14d, 16d: low-pass filter 14e, 16e: postamplifier 20: signal processing unit 22: triangular wave generator 24a, 24b ... A
/ D converter 26: microcomputer 28: arithmetic processing unit

Claims (31)

[Claims] 1. A transmitting means for generating a transmission signal whose frequency gradually increases and decreases periodically with a predetermined modulation width, and transmitting the transmission signal as a radar wave; and receiving the radar wave reflected by a target to generate a reception signal. Generating means for mixing the received signal with the transmission signal to generate a beat signal; and generating an uplink spectrum from an uplink beat signal at the time of uplink modulation in which the frequency of the transmission signal is increased, and Spectrum generating means for generating a downlink spectrum from a downlink beat signal at the time of downlink modulation in which the frequency of the signal decreases, at least one spectrum peak of the uplink spectrum and the downlink spectrum is shifted by a predetermined frequency shift amount, and a correspondence between the two spectra is obtained. Detecting means for comparing the spectral peaks to be detected with each other and detecting the moving state of the target, and an FMCW radar comprising: A plurality of shift amount setting means for setting a plurality of frequency shift amounts in consideration of a measurement error when setting the frequency shift amount based on a speed of a vehicle equipped with the FMCW radar device; Evaluation means for evaluating the degree of spectrum matching for each of the uplink spectrum and the downlink spectrum corresponding to each set frequency shift amount, and determining the highest frequency shift amount of the spectrum match degree based on the evaluation result. An FMCW radar apparatus comprising: a determination unit; and a stationary determination unit configured to determine a stationary state of the target using the uplink spectrum and the downlink spectrum corresponding to the determined frequency shift amount. 2. A method for setting a frequency shift amount based on a speed of a vehicle equipped with the FMCW radar device, the method comprising: determining a basic frequency shift amount and a frequency shift amount deviated by a predetermined amount from the basic frequency shift amount. The FMCW radar device according to claim 1, wherein the setting is performed. 3. The evaluation means according to claim 1, wherein in an uplink spectrum and a downlink spectrum corresponding to each frequency shift amount,
Evaluating the degree of spectral matching for each pair of corresponding spectral peaks of both spectra, based on the evaluation of the degree of spectral matching for each spectral peak, evaluating the degree of spectral matching for each frequency shift amount. The FMCW radar device according to claim 1. 4. The stationary state determining means evaluates a degree of spectrum matching for each of a pair of corresponding spectral peaks of both spectrums in an uplink spectrum and a downlink spectrum corresponding to the determined frequency shift amount. The FMCW radar device according to any one of claims 1 to 3, wherein the determination of the stationary state of the target is performed based on the following. 5. The FMCW radar device according to claim 1, wherein the evaluation of the degree of spectrum matching is performed based on information in a frequency band having a predetermined width of a spectrum peak. 6. The FMCW radar apparatus according to claim 1, wherein the evaluation of the degree of spectrum matching is performed based on amplitude of a spectrum peak and azimuth information of a target. 7. An evaluation of the spectrum matching degree based on an absolute value of an evaluation vector where an amplitude evaluation value based on the amplitude of the spectrum peak is Y and a phase evaluation value based on the azimuth information of the target is X. 7. The FMCW radar device according to claim 6, wherein the operation is performed. 8. A neighborhood sum of absolute values of the evaluation vector with respect to the spectrum peak to be evaluated is obtained for each spectrum peak, and the sum of the neighborhood sums having the smallest total spectrum is determined as the true frequency. The FMCW radar device according to claim 7, wherein the shift amount is a shift amount. 9. A method according to claim 9, wherein the sum of absolute values of the evaluation vector with respect to the spectrum peak to be evaluated is compared with a predetermined threshold, and when the sum is less than or equal to the threshold, the target is determined to be a stationary object. The FMCW radar device according to claim 7 or 8, wherein: 10. The FMCW radar device according to claim 1, wherein a frequency shift amount is set in consideration of a beam direction of the FMCW radar device. 11. A moving object prediction flag is set by predicting a current moving position of a target already recognized as a moving object, and the moving object prediction flag is set for a current spectrum peak to be determined. 11. The FMCW radar device according to claim 1, wherein the target is not determined to be a stationary object when is set. 12. A transmitting means for generating a transmission signal having a predetermined modulation width and a frequency gradually increasing and decreasing periodically and transmitting the signal as a radar wave, receiving the radar wave reflected by a target, and forming a reception signal. Generating means for mixing the received signal with the transmission signal to generate a beat signal; and generating an uplink spectrum from an uplink beat signal at the time of uplink modulation in which the frequency of the transmission signal is increased, and Spectrum generating means for generating a downlink spectrum from a downlink beat signal at the time of downlink modulation in which the frequency of the signal decreases, at least one spectrum peak of the uplink spectrum and the downlink spectrum is shifted by a predetermined frequency shift amount, and a correspondence between the two spectra is obtained. Detecting means for comparing the spectral peaks to be detected with each other and detecting the moving state of the target. In the device, based on the speed of a vehicle equipped with the FMCW radar device, when setting the frequency shift amount, a beam shift amount setting unit that sets the frequency shift amount in consideration of the direction of the radar beam, FMCW radar apparatus comprising: stationary determination means for determining stationary of the target using the uplink spectrum and the downlink spectrum corresponding to the frequency shift amount. 13. The stationary determination means evaluates a degree of spectrum matching for each of a pair of corresponding spectrum peaks of both spectra in an up spectrum and a down spectrum corresponding to the frequency shift amount, and based on the evaluation. 13. The FMCW radar device according to claim 12, wherein the stationary determination of the target is performed. 14. The FMCW radar device according to claim 12, wherein the evaluation of the degree of spectrum matching is performed based on information in a frequency band having a predetermined width of a spectrum peak. 15. The FMC according to claim 8, wherein the evaluation of the degree of spectrum matching is performed based on amplitude of a spectrum peak and azimuth information of a target.
W radar device. 16. An evaluation of the degree of spectrum matching based on an absolute value of an evaluation vector where an amplitude evaluation value based on the amplitude of the spectrum peak is Y and a phase evaluation value based on the azimuth information of the target is X. The FMCW radar device according to claim 15, wherein the FMCW radar device performs the operation. 17. A method according to claim 17, wherein a sum of absolute values of the evaluation vectors related to the spectrum peaks to be evaluated is compared with a predetermined threshold value, and when the sum is less than or equal to the threshold value, the target is determined to be a stationary object. 17. The FMCW radar device according to claim 16, wherein: 18. A moving object prediction flag is set by predicting a current moving position of a target that has already been recognized as a moving object, and the moving object prediction flag is set for a current spectrum peak to be determined. 18. The FMCW radar apparatus according to claim 12, wherein the target is not determined to be a stationary object when is set. 19. A transmitting means for generating a transmission signal whose frequency is gradually increased and decreased periodically with a predetermined modulation width and transmitting the signal as a radar wave, receiving the radar wave reflected by a target, and forming a reception signal. Generating means for mixing the received signal with the transmission signal to generate a beat signal; and generating an uplink spectrum from an uplink beat signal at the time of uplink modulation in which the frequency of the transmission signal is increased, and Spectrum generating means for generating a downlink spectrum from a downlink beat signal at the time of downlink modulation in which the frequency of the signal decreases, at least one spectrum peak of the uplink spectrum and the downlink spectrum is shifted by a predetermined frequency shift amount, and a correspondence between the two spectra is obtained. Detecting means for comparing the spectral peaks to be detected with each other and detecting the moving state of the target. In the device, using the amplitude of the spectrum peak and the azimuth information of the target, for each pair of corresponding spectrum peaks of the two spectra, the degree of spectrum matching is evaluated, and based on the evaluation, the stationary state of the target is determined. An FMCW radar device for making a determination. 20. The FM according to claim 19, wherein the evaluation of the degree of spectrum matching is performed based on information in a frequency band having a predetermined width of a spectrum peak.
CW radar device. 21. An evaluation of the spectrum matching degree based on an absolute value of an evaluation vector where an amplitude evaluation value based on the amplitude of the spectrum peak is Y and a phase evaluation value based on the azimuth information of the target is X. 21. The FMCW radar device according to claim 19, wherein the operation is performed. 22. A method according to claim 22, wherein a sum of absolute values of the evaluation vector with respect to the spectrum peak to be evaluated is compared with a predetermined threshold, and when the sum is less than or equal to the threshold, the target is determined to be a stationary object. 22. The FMCW radar device according to claim 21, wherein: 23. A moving object prediction flag is set for a target already recognized as a moving object by predicting a current moving position, and the moving object prediction flag is set for a current spectrum peak to be determined. 23. The FMCW radar device according to claim 19, wherein the target is not determined to be a stationary object when is set. 24. A transmitting means for generating a transmission signal whose frequency gradually increases and decreases with a predetermined modulation width and transmitting the signal as a radar wave, receiving the radar wave reflected by a target, and forming a reception signal. Generating means for mixing the received signal with the transmission signal to generate a beat signal; and generating an uplink spectrum from an uplink beat signal at the time of uplink modulation in which the frequency of the transmission signal is increased, and Spectrum generating means for generating a downlink spectrum from a downlink beat signal at the time of downlink modulation in which the frequency of the signal decreases, at least one peak of the uplink spectrum and the downlink spectrum is shifted by a predetermined frequency shift amount, and the corresponding spectrum of both spectra is shifted. Detecting means for comparing the peaks with each other to detect the moving state of the target; When a moving object prediction flag is set by predicting a current moving position for a target recognized as an animal, and the moving object prediction flag is set for a spectrum peak to be determined this time, A FMCW radar apparatus characterized in that the target is not determined to be a stationary object. 25. The method according to claim 1, wherein the degree of spectrum matching is obtained based on peak information relating to a peak of the spectrum peak.
23. The FMCW radar device according to any one of 19 to 22. 26. A transmitting means for generating a transmission signal having a predetermined modulation width and a frequency gradually increasing and decreasing periodically and transmitting the signal as a radar wave, receiving the radar wave reflected by a target, and forming a reception signal. Generating means for mixing the received signal with the transmission signal to generate a beat signal; and generating an uplink spectrum from an uplink beat signal at the time of uplink modulation in which the frequency of the transmission signal is increased, and Spectrum generating means for generating a downlink spectrum from a downlink beat signal at the time of downlink modulation in which the frequency of the signal decreases, at least one spectrum peak of the uplink spectrum and the downlink spectrum is shifted by a predetermined frequency shift amount, and in both spectra, Detecting means for comparing corresponding spectral peaks to each other to detect a moving state of the target, and A beam shift amount setting unit that sets the frequency shift amount based on a speed of a vehicle equipped with the FMCW radar device; and a peak of a peak of a spectrum peak of the up spectrum and the down spectrum shifted by the frequency shift amount. Evaluation means for evaluating the degree of spectrum matching based on the information, the evaluation means comprising: a peak of a spectrum peak of both spectra existing within a predetermined width from a peak frequency of a spectrum peak in one of the reference spectra. An FMCW radar device for evaluating a degree of spectrum matching based on information. 27. A transmitting means for generating a transmission signal whose frequency gradually increases and decreases with a predetermined modulation width and transmitting the signal as a radar wave, receiving the radar wave reflected by a target, and forming a reception signal. Generating means for mixing the received signal with the transmission signal to generate a beat signal; and generating an uplink spectrum from an uplink beat signal at the time of uplink modulation in which the frequency of the transmission signal is increased, and Spectrum generating means for generating a downlink spectrum from a downlink beat signal at the time of downlink modulation in which the frequency of the signal decreases. An FMCW radar device comprising: a frequency shift amount based on a speed of a vehicle equipped with the FMCW radar device. Beam shift amount setting means for setting the spectrum peak of one spectrum as a reference, and Shifting means for shifting the vector peak within the range of the frequency shift amount ± predetermined width, and, when shifted to the range, evaluating the degree of spectrum matching based on peak information of the peaks of the spectrum peaks of both spectra. A featured FMCW radar device. 28. The FMCW radar device according to claim 25, wherein the peak information is information on a peak frequency, a peak level, and a phase difference. 29. An evaluation of the degree of spectrum matching based on an absolute value of an evaluation vector, where Y is an amplitude evaluation value based on the amplitude of the spectrum peak, and X is a phase evaluation value based on the azimuth information of the target. The FMCW radar apparatus according to any one of claims 25 to 28, wherein the FMCW radar apparatus performs the operation. 30. comparing an absolute value of the evaluation vector with respect to the spectral peak to be evaluated with a predetermined threshold,
The FM according to claim 29, wherein when the absolute value is equal to or less than a threshold value, the target is determined to be a stationary object.
CW radar device. 31. A recording medium storing means for executing processing by the FMCW radar device according to claim 1. Description: