JP2003011755A - Radar device for vehicle and method for warning degree of risk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely function in all weather and all environment, previously forecast a risk of a collision in various traffic environments, and securely prevent a risk to one's own vehicle which travels at a high speed. SOLUTION: The radar device includes a radar head 1 for receiving a reflection wave from a target of a transmission signal, mixing with a transmission signal, and outputting an amplification beat signal C, and a preceding vehicle warning part 10 including a target processing part 5 for picking up to discriminate a preceding vehicle and a vehicle ahead out of a plurality of targets and a risk warning part 9 for obtaining a degree of the risk of the preceding vehicle to the one's own vehicle in phase comprehensively from the degree of the risk of the preceding vehicle to the one's own vehicle and a degree of a risk of the vehicle ahead to the one's own vehicle and warning a driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle radar device and a danger level warning method therefor, and more particularly to a vehicle radar device for collision prevention using a millimeter wave radar having a preceding vehicle warning function and a danger level warning method therefor.

[0002]

2. Description of the Related Art A radar device for a vehicle mounted on an automobile of this kind can simultaneously monitor the distance and the relative speed by monitoring another automobile traveling in the front or the rear. In particular, the monitoring of a vehicle traveling ahead, that is, a preceding vehicle prevents a rear-end collision or a collision accident of the vehicle, and is expected to be very useful in the future.

Such a preceding vehicle warning function is provided with a sensing device for capturing a vehicle traveling ahead of the host vehicle, and when safety cannot be ensured for vehicles located on the own lane, there is a risk of collision. Is to give a warning to the driver by an alarm sound or the like. The risk of a collision is usually calculated by calculating the degree of danger based on the distance between the own vehicle and the preceding vehicle, the relative speed, etc., and issuing a caution caution or a collision danger warning to the driver in stages according to the degree of the degree of danger. Emit. It is necessary for the driver to issue the collision caution warning and the collision danger warning at an appropriate timing.

An optical radar has been generally used as the sensing device. The first conventional vehicle radar device using this optical radar is small in size, low in cost, and capable of capturing a vehicle of 100 m or more. However, the optical radar interferes with the transmission of light when rainfall, snowfall, and fog occur, and when strong light with a spectrum similar to the wavelength used by the optical radar is input, such as the Nishinichi Due to problems such as difficulty in discrimination, reliable operation cannot be expected under all weather conditions and all environments, and there are many problems in terms of performance.

In recent years, radio wave radar has been rapidly developed and is becoming popular as a vehicle sensing device. In particular, a millimeter wave FMCW radar device using a millimeter wave band radio wave is widely used because of its simple device configuration.

The FMCW radar device transmits a continuous wave FM-modulated by a modulating triangular wave as a transmission wave toward an obstacle such as an automobile located in front, and a reflected wave reflected by the obstacle and returning. It is possible to calculate the distance to an obstacle and the relative velocity by taking in as a received wave and processing a beat signal obtained by mixing the transmitted wave and the received wave at that time by a frequency analysis method such as FFT. it can.

The second conventional vehicle radar system using the millimeter wave radar can detect many obstacles existing in the field. For example, in front of the preceding vehicle used in the present invention. We know that it is possible to capture a car.

In the conventional first and second vehicular radar devices and the method for warning the degree of danger, only the risk judgment for the preceding vehicle is made, so that it is difficult to detect the danger at an early stage according to the road traffic situation. There was a problem.

The degree of danger of the preceding vehicle with respect to the own vehicle is calculated from the time between the preceding vehicle and the relative speed and relative acceleration, and the driver is alerted or the warning is given in a stepwise manner according to the degree of the degree of danger. It is emitted to the hearing.

However, in the conventional method, the danger warning is issued by judging the preceding vehicle closest to the own vehicle, and therefore the danger warning is issued flexibly or early in accordance with various traffic conditions. To do this, there is a problem that information on only the preceding vehicle is not enough. For example, when vehicles are running in a row, it cannot be predicted that the preceding vehicle will suddenly decelerate due to the preceding vehicle approaching the vehicle in front of it. Potentially exposed to. This potential danger is caused by the behavior of a vehicle ahead or a vehicle ahead of the driver, and it is difficult to predict if only the preceding vehicle is focused.

As described above, when the preceding vehicle approaches the preceding vehicle further ahead and falls below the minimum inter-vehicle distance, the preceding vehicle is likely to suddenly decelerate, and the risk of the own vehicle increases. However, it is extremely difficult to catch this phenomenon by the conventional method. Therefore, there is a problem that the driver is exposed to potential danger because it is not possible to detect the danger in advance and notify the driver.

[0012]

SUMMARY OF THE INVENTION The above-mentioned first conventional vehicle radar device prevents the transmission of light when rainfall, snowfall, or fog occurs, and has a spectrum similar to the wavelength used by the optical radar such as the Nishinichi. In the case of strong light input, it is difficult to distinguish it from the received reflection signal, so reliable operation cannot be expected in all weather and all environments, and there are many problems in terms of performance. was there.

Further, since the conventional first and second radar devices for a vehicle only make a risk judgment with respect to a preceding vehicle,
There is a drawback that it is difficult to detect danger early depending on road traffic conditions.

The object of the present invention is to solve the above-mentioned drawbacks of the conventional method, to surely function under all weather and all environments, and to predict the danger of collision in various traffic environments in advance, and to provide a vehicle that runs at high speed. It is an object of the present invention to provide a vehicular radar device and a method for warning a degree of danger thereof that can reliably avoid such a risk.

[0015]

A radar device for a vehicle according to a first aspect of the present invention detects the distance between the vehicle and a target that is an obstacle and a relative speed with respect to the target by using a radio signal to detect the distance. In a vehicle radar device that issues a warning to the driver for the degree of danger to the target vehicle of the target,
A radar head that transmits the radio wave signal as a transmission signal, receives a reflected wave from the target, outputs a beat signal by mixing with the transmission signal, and processes the beat signal to output from a plurality of the targets. The preceding vehicle which is the vehicle on the own lane closest to the own vehicle and the forward vehicle which is the vehicle on the own lane closest to the preceding vehicle located in front of the preceding vehicle are captured and identified, and the preceding vehicle of the preceding vehicle is identified. And a preceding vehicle warning means for issuing the warning to the driver by stepwisely determining the degree of danger of the preceding vehicle with respect to the own vehicle from the degree of danger to the vehicle and the degree of danger of the preceding vehicle to the preceding vehicle. The preceding vehicle warning means performs a frequency analysis of the beat signal to detect a plurality of targets from a frequency spectrum associated with the targets, Target processing means for capturing and identifying the preceding vehicle and the preceding vehicle from the get, and calculating a first risk degree of the preceding vehicle with respect to the own vehicle and a second risk degree of the preceding vehicle with respect to the preceding vehicle. And a danger warning means for issuing the warning to the driver by stepwisely obtaining the danger level of the preceding vehicle with respect to the own vehicle from the first and second danger levels.

According to a second aspect of the present invention, in the vehicle radar apparatus according to the first aspect, the radar head is
FMC with triangular wave frequency modulation for millimeter wave continuous wave
It is configured with a W radar.

According to a third aspect of the present invention, a radar device for a vehicle detects a distance between a host vehicle and a target which is an obstacle and a relative speed of the target by using a radio wave signal, and sends the target vehicle to the target vehicle. In a vehicular radar device that issues a warning to the driver in order to determine the degree of danger of, a radio wave signal that is an FMCW signal obtained by frequency-modulating a continuous wave in the millimeter wave band into a triangular wave is transmitted as a transmission signal, and a reflected wave from the target is transmitted. A radar head that receives and mixes with the transmission signal and outputs a beat signal, a low-pass filter that removes high-frequency components of the beat signal and outputs a low-pass beat signal, and an amplified beat signal that amplifies the low-pass beat signal. And an information processing of the digital beat signal obtained by analog-digital (A / D) converting the amplified beat signal. The preceding vehicle, which is the vehicle on the own lane closest to the own vehicle, and the preceding vehicle, which is the vehicle on the own lane closest to the preceding vehicle located in front of the preceding vehicle, are captured from among the plurality of targets. The warning is given to the driver by discriminating and stepwise obtaining the danger level of the preceding vehicle with respect to the own vehicle comprehensively from the risk degree of the preceding vehicle with respect to the own vehicle and the danger degree of the preceding vehicle with respect to the preceding vehicle. Is provided, and a yaw rate sensor that measures the angular velocity of the vehicle on a curved road and outputs the angular velocity value. The preceding vehicle alarm unit performs A / D conversion on the amplified beat signal and samples at a fixed time. An A / D converter that outputs the digital beat signal that is discrete value data of the amplified beat signal that has been generated; and the preceding of the own vehicle that processes the digital beat signal. Target processing unit for outputting target information including distance and relative speed and recognition of the preceding vehicle and the preceding vehicle, a radius estimator for calculating a road radius from the angular velocity value obtained from the yaw rate sensor, and the road radius A vehicle trajectory estimator that calculates a vehicle trajectory that is a trajectory of the vehicle based on the above, and determines whether the target has a high risk to the vehicle based on the target information from the target processing unit. And a danger alarm unit that operates.

According to a fourth aspect of the present invention, in the vehicle radar device according to the third aspect, the target processing unit extracts a spectrum from the digital beat signal by using a frequency component analysis method by FFT. A processor, a target detector that calculates distance-speed information that is a relative speed between the vehicle and the target based on the extracted spectrum, and the preceding vehicle based on the distance-speed information. And a preceding vehicle recognizer which recognizes the preceding vehicle based on the distance and speed information and outputs the preceding vehicle information.

According to a fifth aspect of the present invention, in the vehicular radar device according to the third aspect, the danger warning unit detects the preceding vehicle with respect to the own vehicle based on the preceding vehicle information and the preceding vehicle information. A preceding vehicle danger alarm determiner that calculates a degree of danger and outputs a preceding vehicle risk determination signal, and a preceding vehicle danger alarm determiner that calculates a degree of danger of the preceding vehicle with respect to the preceding vehicle and outputs a preceding vehicle risk determination signal And, based on the preceding vehicle risk determination signal, the preceding vehicle risk determination signal, and the collision avoidance action amount determination signal described later, comprehensively calculates the risk degree of the own vehicle with respect to the preceding vehicle and determines the preceding vehicle risk degree. A preceding vehicle danger level determiner that outputs a signal, an alarm device that alerts the driver in stages based on the preceding vehicle risk level determination signal, such as an alarm sound, and the driver of the own vehicle performs brake operation. Whether the Tsu brake ON /
Judgment by OFF detection and judgment result brake ON / OF
A brake ON / OFF determiner that outputs an F determination signal,
An own vehicle deceleration degree determiner for determining how much the vehicle is decelerating by a brake operation of the own vehicle and outputting a determination result of the own vehicle deceleration degree; and the brake ON / OF.
And a collision avoidance action amount determiner that comprehensively determines how much the vehicle is performing collision avoidance based on the F determination signal and the own vehicle deceleration degree determination signal, and outputs a collision avoidance action amount determination signal. It is configured.

According to a sixth aspect of the present invention, there is provided a method of warning a degree of danger of a radar device for a vehicle, wherein the target is detected by detecting a distance between the vehicle and a target which is an obstacle and a relative speed of the target by using a radio signal. In the method for warning the degree of danger of a radar device for a vehicle, which issues a warning to the driver to determine the degree of danger to the own vehicle, a preceding vehicle which is a vehicle on the own lane closest to the own vehicle from among the plurality of targets, and From the degree of danger of the preceding vehicle to the own vehicle and the degree of danger of the preceding vehicle to the preceding vehicle, the preceding vehicle that is the vehicle on the own lane closest to the preceding vehicle located in front of the preceding vehicle is captured and identified. It is characterized in that the degree of danger of the preceding vehicle with respect to the own vehicle is comprehensively obtained stepwise to issue the warning to the driver.

According to a seventh aspect of the present invention, in the method for warning a degree of danger of a vehicle radar device according to the sixth aspect, the radio signal is an FMCW signal obtained by frequency-modulating a continuous wave in the millimeter wave band into a triangular wave. It is characterized by being.

According to another aspect of the present invention, there is provided a method for warning a degree of danger of a radar device for a vehicle, which uses an FMCW signal obtained by subjecting a continuous wave in a millimeter wave band to frequency modulation of a triangular wave to a target vehicle and an obstacle. In a danger degree warning method of a vehicle radar device, which detects a distance and a relative speed with respect to the target and obtains a danger degree of the target to the own vehicle and issues a warning to a driver, a transmission signal which is the FMCW signal is received. Frequency analysis is performed on a digital beat signal corresponding to an up zone and a down zone (hereinafter referred to as an upper and lower zone) of the triangular wave generated by A / D converting a beat signal generated by mixing a received signal which is a reflected wave from the target. Then obtain the spectrum of the upper and lower sections, of each peak pair obtained by pairing the corresponding peaks of all peaks of the spectrum of the upper and lower sections A target on the own lane is selected by using the own vehicle trajectory calculated in the yaw rate sensor processing step described later together with the separation and the relative speed, and the own vehicle is selected from the plurality of targets on the own lane. The preceding vehicle which is the vehicle on the own lane closest to the vehicle and the preceding vehicle which is the vehicle on the own lane closest to the preceding vehicle located in front of the preceding vehicle are respectively recognized, and the corresponding preceding vehicle information EC and the forward vehicle information Based on the target recognition processing step of outputting vehicle information ED and the preceding vehicle information and the preceding vehicle information, the degree of danger of the preceding vehicle with respect to the own vehicle is calculated to generate a preceding vehicle risk determination signal, The degree of danger of the vehicle with respect to the preceding vehicle is calculated to generate a forward vehicle risk degree determination signal, and the preceding vehicle risk degree determination signal, the forward vehicle risk degree determination signal, and a collision avoidance action processing step described later. From the collision avoidance action amount determination signal calculated in step 1, the overall degree of danger of the preceding vehicle with respect to the own vehicle is calculated and a preceding vehicle risk degree determination signal is output. If the judgment is made, the road radius is calculated together with the speed information of the own vehicle based on the risk discrimination processing step that calls the driver's attention by the warning display and the angular velocity output from the yaw rate sensor. A yaw rate sensor processing step of calculating a vehicle locus which is a road locus traveling after time and supplying the vehicle locus to the target recognition processing step, and a brake ON / OFF determination as to whether or not the brake of the vehicle is operated. Judgment by signal, judgment result of deceleration degree by deceleration means including brake ON / OFF by this brake ON / OFF judgment signal The collision avoidance action amount of how much the own vehicle is performing collision avoidance is calculated with the own vehicle deceleration degree determination signal,
A collision avoidance action processing step of outputting the collision avoidance action amount and supplying the collision avoidance action amount to the risk determination processing step.

According to a ninth aspect of the present invention, in the method for warning a degree of danger of a vehicular radar device according to the eighth aspect, the target recognition processing step performs AD conversion of the beat signals in the upper and lower sections to obtain the upper and lower sections. Upper and lower section AD conversion step of generating the digital beat signal, upper and lower section frequency analysis step of performing spectrum conversion by frequency analysis on each of the upper and lower sections of the digital beat signal and outputting the spectrum, Detecting all peaks in the upper and lower sections, pairing the corresponding peaks of each of the detected upper and lower sections to generate a peak pair, a peak pairing step, and targeting all the peak pairs in the upper and lower sections. After the distance / relative speed calculation step to calculate the distance and relative speed of each peak pair, And a target on the own lane selected in the target selection step on the own lane for extracting a target on the own lane based on the own vehicle trajectory estimated in the own vehicle trajectory estimation calculation step The preceding vehicle recognition step of recognizing the vehicle closest to the own vehicle as the preceding vehicle, and the vehicle closest to the preceding vehicle among the targets on the own lane selected in the preceding vehicle recognition step as the preceding vehicle The yaw rate sensor processing step performs AD conversion of the angular velocity from the yaw rate sensor,
A yaw rate value converting step for generating a digital angular velocity, a road radius estimating and calculating step for calculating a road radius from the digital angular velocity, and traveling after the current time of the vehicle based on the road radius estimated in the road radius estimating and calculating step. A vehicle locus estimation / calculation step of estimating the vehicle locus, which is a road locus to be run.

Further, the invention according to claim 10 is the invention according to claim 8.
In the method of warning the degree of danger of the vehicle radar device described,
The risk determination processing step includes a relative acceleration calculation step of calculating a relative acceleration of the preceding vehicle with respect to the own vehicle and a relative acceleration of the preceding vehicle with respect to the preceding vehicle, and a preceding step that is a degree of danger of the preceding vehicle with respect to the own vehicle. A preceding vehicle risk degree calculating step for calculating a vehicle risk degree, a forward vehicle risk degree calculating step for calculating a forward vehicle risk degree which is a risk degree of the preceding vehicle with respect to the preceding vehicle, a preceding vehicle risk degree and the preceding vehicle risk Based on a degree and a risk avoidance action amount described later, a preceding vehicle total risk degree calculating step of calculating a comprehensive risk degree of the preceding vehicle with respect to the own vehicle, and the collision avoidance action processing step is performed by the driver. The brake ON / OFF determination step to determine whether the foot brake operation is being performed and the deceleration of the own vehicle are calculated, and the degree of danger is high. It is characterized in that it has a vehicle deceleration of about calculating step of calculating whether a risk avoidance behavior amount driver if is how decelerated.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail with reference to the drawings.

The vehicle radar device of the present embodiment detects the distance between the vehicle and the target which is an obstacle and the relative speed of the target by using the radio signal to detect the degree of danger of the target to the vehicle. In the vehicle radar device that issues a warning to the driver, a radar head that transmits the radio wave signal as a transmission signal, receives a reflected wave from the target, mixes with the transmission signal and outputs a beat signal, and the beat signal Processing to identify the preceding vehicle that is the vehicle on the own lane closest to the own vehicle and the preceding vehicle that is the vehicle on the own lane closest to the preceding vehicle ahead of this preceding vehicle However, from the degree of danger of the preceding vehicle to the own vehicle and the degree of risk of the preceding vehicle to the preceding vehicle, the driver comprehensively obtains the degree of danger of the preceding vehicle to the own vehicle stepwise. A preceding vehicle warning means for issuing a notification, the preceding vehicle warning means performs frequency analysis of the beat signal to detect a plurality of targets from the frequency spectrum related to the target, and the preceding vehicle and the preceding vehicle among the plurality of targets. And a target processing means for capturing and identifying the first risk degree of the preceding vehicle with respect to the own vehicle and a second risk degree of the preceding vehicle with respect to the preceding vehicle are calculated, and combined from the first and second risk degrees. In addition, a danger warning means for warning the driver by gradually obtaining the degree of danger of the preceding vehicle with respect to the own vehicle is provided.

With this feature, it is possible to detect a potential danger that the own vehicle is also in danger when the preceding vehicle and the preceding vehicle are close to each other.

That is, in the present embodiment, the preceding vehicle, which is the vehicle on the own lane closest to the own vehicle among the plurality of targets using the radio wave radar on the highway or the like, and the preceding vehicle located in front of the preceding vehicle. The front vehicle, which is the vehicle closest to the vehicle in front of the vehicle, is captured, and the overall degree of danger of the preceding vehicle to the vehicle is calculated step by step from the degree of danger of the preceding vehicle to the vehicle and the degree of risk of the preceding vehicle to the preceding vehicle. To warn the driver.

Next, referring to FIG. 1, which is a block diagram showing an embodiment of the present invention, the vehicle radar device of the present embodiment shown in this figure performs frequency modulation of a triangular wave on a continuous wave in the millimeter wave band. It is an FMCW radar, and F from the transmitting antenna
A radar head 1 that transmits an MCW modulated wave, receives a reflected wave from a target (an obstacle such as an automobile) with a reception antenna, mixes the received signal with the transmitted wave, and outputs a beat signal A 1.
A low-pass filter (LPF) 2 that removes high-frequency components of the beat signal A and outputs a low-pass beat signal B; an amplifier 3 that amplifies the low-pass beat signal B and outputs an amplified beat signal C; and an amplified beat signal C that is analog. Information processing of digital (A / D) -converted digital beat signals is performed to capture and identify a vehicle ahead of the own vehicle, and the degree of danger of the preceding vehicle to the own vehicle and the degree of risk of the preceding vehicle to the preceding vehicle are comprehensively determined. The preceding vehicle warning unit 10 that issues a warning to the driver by stepwise determining the degree of danger to the vehicle, and the yaw rate sensor 6 that measures the angular velocity of the vehicle on a curved road (hereinafter referred to as a curved road) and outputs the angular velocity F are provided. Prepare

The preceding vehicle alarm unit 10 is composed of a microprocessor, converts the amplified beat signal C into an analog-digital (A / D) signal, and digital beat signal D which is discrete value data of the amplified beat signal C sampled at a constant time. An A / D converter 4 for outputting the target information, and a target processing unit 5 for processing the digital beat signal D and outputting target information E including the distance and relative speed of the preceding vehicle to the own vehicle and recognition of the preceding vehicle and the preceding vehicle, A radius estimator 7 for calculating a road radius G from the angular velocity F obtained from the yaw rate sensor 6 and the like.
Based on the road radius G, the own vehicle locus estimator 8 for calculating the own vehicle locus H, which is the locus of the own vehicle traveling, and the target information E from the target processing unit 5, the degree of danger from the target to the own vehicle. And a danger warning unit 9 for determining whether or not it is high.

The target processing unit 5 extracts a spectrum EA from the digital beat signal D by using a frequency component analysis method such as FFT (Fast Fourier Transform) and a frequency analysis processor 51 based on the extracted spectrum EA. A target detector 52 that calculates distance-speed information EB that is the relative speed between the vehicle and an obstacle (target) and the relative speed to the vehicle, and a preceding vehicle that recognizes the preceding vehicle based on the distance-speed information EB and outputs the preceding-vehicle information EC. A vehicle recognizer 53 and a forward vehicle recognizer 54 that recognizes a forward vehicle based on the distance / speed information EB and outputs the forward vehicle information ED are provided.

Referring to FIG. 2, which shows a block diagram of an example of the configuration of the danger warning unit 9, the danger warning unit 9 shown in this figure is based on the preceding vehicle information EC and the preceding vehicle information ED, and the degree of danger of the preceding vehicle to the own vehicle. And a preceding vehicle danger warning determiner 91 that calculates the preceding vehicle danger level determination signal JA, and a preceding vehicle danger warning determiner 92 that calculates the degree of danger of the preceding vehicle with respect to the preceding vehicle and outputs a preceding vehicle danger level determination signal JB. Based on the preceding vehicle risk determination signal JA, the preceding vehicle risk determination signal JB, and the collision avoidance action amount determination signal JF described later, the degree of danger of the own vehicle relative to the preceding vehicle is comprehensively calculated to determine the degree of risk of the preceding vehicle. JC
Of the preceding vehicle danger level determiner 93, an alarm device 94 that alerts the driver step by step with an alarm sound or the like based on the preceding vehicle danger level determination signal JC, and whether or not the driver of the own vehicle is braking. Brake ON /
Judgment by OFF detection and judgment result brake ON / OF
The brake ON / OFF determiner 95 that outputs the F determination signal JD, and the own vehicle deceleration degree that determines the extent to which the vehicle is decelerating due to the brake operation of the own vehicle and is the determination result JE is output. Judgment device 96 and brake O
A collision avoidance action amount determiner that comprehensively determines how much the own vehicle is performing collision avoidance based on the N / OFF determination signal JD and the own vehicle deceleration degree determination signal JE and outputs a collision avoidance action amount determination signal JF. 97 and.

Next, the schematic operation of the present embodiment will be described with reference to FIGS. 1 and 2. First, the radar head 1 transmits an FMCW modulated wave FM-modulated by a triangular wave from a transmission antenna to an automobile or the like. Send towards the obstacle. The reception antenna receives the reflected wave reflected by the obstacle, mixes the received signal with the transmitted wave to generate a beat signal A, and supplies the beat signal A to the LPF 2.

The LPF 2 removes the high frequency component of the beat signal A, outputs a low pass beat signal B, and supplies it to the amplifier 3. The amplifier 3 amplifies the low-pass beat signal B, outputs an amplified beat signal C, and supplies it to the A / D converter 4 of the preceding vehicle warning unit 10. The A / D converter 4 performs analog-digital (A / D) conversion of the amplified beat signal C to generate a digital beat signal D which is discrete value data of the beat signal sampled at a constant time, and the preceding vehicle warning unit 10 outputs It is stored in an internal memory (not shown).

In the target processing section 5, first, the frequency analysis processor 51 extracts the spectrum EA from the digital beat signal D by using FFT. Next, the target detector 52 calculates obstacles such as a vehicle in front of the own vehicle, that is, the distance to the target and the distance / speed information EB, which is the relative speed, based on the spectrum EA. Next, the preceding vehicle recognizer 53 recognizes the vehicle on the own lane closest to the own vehicle, that is, the preceding vehicle from the plurality of targets based on the distance / speed information EB, outputs the preceding vehicle information EC, and outputs the danger. It is supplied to the alarm unit 9. Similarly, the front vehicle recognizing device 54 recognizes the vehicle on the own lane closest to the preceding vehicle located ahead of the preceding vehicle, that is, the preceding vehicle from the plurality of targets based on the distance speed information EB. The information ED is output and supplied to the danger alarm unit 9. In order to identify the preceding vehicle and the preceding vehicle, a vehicle locus H calculated by a vehicle locus estimator 8 described later is used.

The danger warning unit 9 determines the degree of danger of the preceding vehicle to the own vehicle from the distance and the relative speed of the preceding vehicle, which is the closest target obtained by the preceding vehicle recognizer 53, and determines the driver to the degree of danger. On the other hand, a warning is given or a warning sound is given. First, the preceding vehicle danger warning determiner 91
Calculates the degree of danger of the preceding vehicle with respect to the own vehicle on the basis of the preceding vehicle information EC and the preceding vehicle information ED, generates a preceding vehicle risk degree determination signal JA which is the calculation result, and supplies it to the preceding vehicle risk degree determiner 93. . Similarly, the forward vehicle danger warning determiner 92
Calculates the degree of danger of the preceding vehicle with respect to the preceding vehicle, generates a preceding vehicle danger degree determination signal JB, which is the calculation result, and supplies it to the preceding vehicle danger degree determiner 93. Preceding vehicle danger degree judging device 93
Is a calculation result obtained by comprehensively calculating the degree of danger of the preceding vehicle relative to the own vehicle based on the preceding vehicle risk determination signal JA, the preceding vehicle risk determination signal JB, and the collision avoidance action amount determination signal JF described later. The danger degree determination signal JC is generated and supplied to the alarm device 94. The alarm device 94 warns the driver step by step with an alarm sound and an alarm display based on the preceding vehicle danger level determination signal JC.

On the other hand, the brake ON / OFF judging device 95
Determines whether or not the driver of the vehicle is performing a brake operation by detecting the brake ON / OFF, generates a brake ON / OFF determination signal JD of the determination result, and supplies it to the collision avoidance action amount determiner 97. The own vehicle deceleration degree determining unit 96 determines how much the vehicle is decelerating due to a brake operation of the own vehicle, generates a determination result JE of the own vehicle deceleration degree, and supplies it to the collision avoidance action amount determining unit 97. .
The collision avoidance action amount determiner 97 comprehensively determines how much the own vehicle avoids collision based on the brake operation ON / OFF indicated by the brake ON / OFF determination signal JD and the deceleration degree indicated by the own vehicle deceleration degree determination signal JE. The collision avoidance action amount determination signal JF is generated, and the preceding vehicle danger degree determination device 93 is generated.
Supply to.

The yaw rate sensor 6 measures the angular velocity of the vehicle on a curve of a road or the like, generates an angular velocity F, and supplies it to the radius estimator 7 of the preceding vehicle warning unit 10. The radius estimator 7 calculates the road radius G from the angular velocity F and the like,
It is supplied to the own vehicle trajectory estimator 8. The vehicle locus estimator 8 is a vehicle locus H which is a locus of the vehicle traveling based on the road radius G.
Is calculated and supplied to the target processing unit 5.

Next, the overall processing flow of the preceding vehicle warning section 10 including the danger warning processing by the target processing section 5, the radius estimator 7, the own vehicle trajectory estimator 8, and the danger warning section 9 and the collision avoidance action processing will be described with a flowchart. Referring also to FIG. 3 shown, the preceding vehicle alarm unit 10 includes a frequency analysis processor in addition to the main routine which is the overall processing flow shown in FIG.
It is supported by various operating programs.

In the overall processing flow, since the engine of the vehicle is first operated, the ignition key is operated to turn on the power, and after a lapse of a fixed time after the power is turned on, the reset of the radar information processing section is released. When the reset is released, the microprocessor constituting the preceding vehicle warning unit 10 is activated and the program is executed from the zero address.

First, in the initialization step S1,
Initialize and initialize various variables.

Next, the target recognition processing step S2 is executed. Referring again to FIG. 1 again, the FMCW transmission signal by the triangular wave transmitted from the radar head 1 is reflected by an obstacle, that is, the target and returns as a reception signal, and the beat signal A is mixed by mixing these transmission and reception signals.
To generate. On the other hand, at the same time that the FMCW transmission signal is transmitted, the A / D converter 4 starts A / D conversion of the amplified beat signal C corresponding to the beat signal A, and generates a digital beat signal D that is discrete-valued data. To do. This digital beat signal D is stored in a memory inside the radar information processing unit one by one. Further, this A / D conversion is executed at fixed sampling times, and therefore, in general, a timer interrupt or the like is often used to monitor the sampling time. The digitization of the amplified beat signal C by the A / D converter 4 is executed for one cycle of the triangular wave. At this point, the digital beat signal D of the amplified beat signal C corresponding to the rising section and the falling section of the triangular wave has been accumulated in the radar information processing unit.

Therefore, the digital beat signal D of the amplified beat signal C corresponding to the rising section and the falling section of the triangular wave.
To obtain a discrete spectrum of each section by a frequency analysis method represented by FFT or the like.

Next, all peaks of the spectrum in the upper and lower sections are detected, and the corresponding peaks in the detected upper and lower sections are paired. The distance and relative speed of each peak pair are calculated, and the target vehicle trajectory H is also used together with the target vehicle trajectory H calculated in the later-described yaw rate sensor processing step S4 to select a target on the target vehicle lane. And the preceding vehicle are recognized, and corresponding preceding vehicle information EC and corresponding forward vehicle information ED (both information E together) are output.

Next, the risk discrimination processing step S3 is performed.
Referring again to FIG. 2 again, based on the processing result of the target recognition processing step S2 and the preceding vehicle information EC and the preceding vehicle information ED output from the target processing unit 5, first, the degree of danger of the preceding vehicle to the own vehicle is determined. A leading vehicle risk determination signal JA is calculated and generated. Subsequently, the degree of danger of the preceding vehicle with respect to the preceding vehicle is calculated, and the preceding vehicle danger level judgment signal JB is generated. Judgment signal J for each of these preceding and preceding vehicles
A, JB, and the collision avoidance action amount determination signal JF calculated in step S5 are used to calculate the overall degree of danger of the preceding vehicle with respect to the own vehicle, and the preceding vehicle risk degree determination signal JC is output. When it is determined from the preceding vehicle danger level determination signal JC that the risk level is high, the driver is alerted by a warning display.

Next, the yaw rate sensor processing step S4
With reference to FIG. 1 again, the road radius G is calculated based on the angular velocity F output from the yaw rate sensor 6 together with the speed information of the vehicle. Road radius G
From this, the vehicle locus H after the current time is calculated, and this vehicle locus H is calculated.
Is supplied to the target recognition processing step S2.

Next, the collision avoidance action processing step S5 will be described with reference to FIG. 2 again. First, it is determined whether or not the brake of the own vehicle has been operated by turning the brake ON / O.
Judgment is made by the FF judgment signal JD. Brake ON / OFF
Collision avoidance behavior based on how much the own vehicle is performing collision avoidance based on the on / off of the brake based on the determination signal JD and the own vehicle deceleration degree determination signal JE which is the determination result of the degree of deceleration by the brake operation of the own vehicle and other deceleration means The amount is calculated, the collision avoidance action amount determination signal JF is output, and supplied to the risk determination processing step S3.

Next, the details of the target recognition processing step S2 and the yaw rate sensor processing step S4 will be described with reference to FIG. 4 which is a flowchart showing the processing flow of the target recognition processing step S2 and the yaw rate sensor processing step S4. First, the vertical section A
In the D conversion step S21, the A / D converter 4 sets the amplifier 3
The upstream section and the downstream section of the amplified beat signal C supplied from the A / D converter are AD-converted. The discrete value of the amplified beat signal C that has been AD-converted, that is, the digital beat signal D is stored in the memory inside the preceding vehicle warning unit 10.

Next, the upper and lower frequency analysis step S22
Then, spectrum conversion is performed on the up section and the down section of the digital beat signal D by frequency analysis by FFT or the like, and the spectrum EA is output.

Upper and lower section peak pairing step S23
Then, all peaks in the upper and lower sections are detected from the spectrum EA,
The detected peaks in the upper and lower sections are paired with each other to generate a peak pair. The means for detecting all peaks extracts spectral peaks having peak levels above a predetermined standard threshold.

In distance / relative speed calculation step S24, the distance and relative speed of each peak pair are calculated for all peak pairs in the upper and lower sections obtained in step S23. Assuming that the peak frequency in the up section of each peak pair is fa (Hz) and the peak frequency in the down section is fb (Hz), the distance R
And the relative velocity V are respectively expressed by the following equations.

Distance R = A · ((fa + fb) / 2) Relative speed V = A · ((fa−fb) / 2) (A: constant) (1) On the other hand, the yaw rate value In the conversion step S41, the angular velocity from the yaw rate sensor 6 is AD-converted. The digital angular velocity, which is the discrete value of the AD-converted angular velocity, is accumulated inside the radar information processing unit 10.

In the road radius estimation / calculation step S42, the road radius is calculated from the digital angular velocity. First, the rotation angle θn (de
g) and determine the running length of the vehicle at this time T
Assuming (m), the road radius RC is expressed by the following equation.

Road radius RC = D / (θn · (π / 180)) (2) In the vehicle trajectory estimation calculation step S43, the current vehicle location is calculated based on the road radius estimated in step S42. The vehicle locus, which is the road locus traveling after the time, is estimated. It is known that the accuracy of the yaw rate greatly affects the estimation of the vehicle trajectory.

Target selection step S25 on own lane
Then, the target on the own lane is extracted based on the own vehicle trajectory estimated in step S43. In order to extract the target on the own lane, the own vehicle trajectory is estimated in advance and the vehicle located within the trajectory range is selected.

In the preceding vehicle recognition step S26, the step S
From the targets on the own lane selected in 25, the vehicle closest to the own vehicle is recognized as the preceding vehicle.

Referring to FIGS. 6 (A) and 6 (B), which are explanatory diagrams showing how the preceding vehicle is recognized on a straight road and a curved road, respectively, the vehicle 101 on the own lane can be used in any road environment.
The preceding vehicle closest to is recognized as the preceding vehicle 102.

Subsequently, in the front vehicle recognition step S27, the vehicle closest to the preceding vehicle 102 among the targets on the own lane selected in step S25 is recognized as the front vehicle 103.

Referring again to FIG. 6, the front vehicle closest to the preceding vehicle 102 on the own lane is recognized as the front vehicle 103 in both the straight road (A) and the curved road (B) road environments. . In this case, since the preceding vehicle 102 and the preceding vehicle 103 do not overlap each other on the curved road, both vehicles can be detected within the left and right detection range of the radar device.

On the other hand, in the case of a straight road, if the own vehicle 101 is a normal passenger vehicle, the front vehicle 103 is masked by the preceding vehicle 102 and is difficult to visually recognize. In a radio wave radar using the millimeter wave band, the radio wave in the millimeter wave band is transmitted by the preceding vehicle 10 due to the reflection characteristic that the straight line is extremely high and a substance other than a metal substance can be obtained.
2 passes through the lower part of the vehicle body and the road surface, passes through, is reflected by the front vehicle 103, is reflected again between the lower part of the vehicle body of the preceding vehicle 102 and the road surface, and is received by the host vehicle 101.

Referring to FIG. 7 which is an explanatory view showing an example of the detection characteristics of the preceding vehicle and the preceding vehicle on a straight road, in this figure, (A)
As shown in FIG. 5, the front vehicle 103 and the front vehicle 103 are detected when the front vehicle 103 is fixed about 100 m ahead and the preceding vehicle 102 is run from several meters until the front vehicle 103 is approached. Assuming that three cars are running in a row, the inter-vehicle distance is about 50 m, but as shown in (B), the area around 50 m is the area where both the preceding vehicle and the preceding vehicle are detected, Sex can be judged to be sufficient.

Next, the details of the danger warning processing step S3 and the collision avoidance action processing step S5 will be described with reference to FIG. 5 which is a flowchart showing the processing flow of the danger warning processing step S3 and the collision avoidance action processing step S5. Then, first, the relative acceleration calculation step S31
Then, the relative acceleration of the preceding vehicle 102 with respect to the own vehicle 101 and the relative acceleration of the preceding vehicle 103 with respect to the preceding vehicle 102 are obtained by the following equations.

In the preceding vehicle risk degree calculation step S32, the risk degree DD1 (n) of the preceding vehicle 102 with respect to the host vehicle 101 is calculated.
Is calculated from the following equation.

DD1 (n) = DTdiff + kdvr × Dvr + kdar × Dar + kdd × DD1 (n-1) (4) DTdiff: Margin Danger degree due to inter-vehicle time Kdvr: Weighting coefficient Dvr: Possibility of danger due to relative speed Kdar: Weighting coefficient Dar: Possibility of danger due to relative acceleration The surplus inter-vehicle time Tdiff in Equation 4 is obtained by the following equation. The surplus inter-vehicle time is a time difference between the actual inter-vehicle time and the minimum inter-vehicle time, and serves as a measure of how much the extra inter-vehicle time is with respect to the minimum inter-vehicle time Tmin.

Tdiff = Tdis−Tmin (5) Tdiff: Extra headway time Tdis: Headway time or minimum headway time Tmin is calculated by the following equation.

Although the free running time Tdelay of the own vehicle varies depending on the driver, it is generally considered to be about 0.5 s to 1.5 s.

The above-mentioned numerical values are generally used for the own vehicle deceleration and the preceding vehicle deceleration, but the deceleration varies depending on the vehicle and the like. In particular, the deceleration of large trucks is said to be about 0.5G at most.

Referring to FIG. 8 which shows an example of parameter setting for calculating the degree of danger DD1 (n), referring to FIG. 8, an example of setting the degree of danger DTdiff depending on the headway time is set to (A) and the possibility of danger Dvr depending on relative speed is set. For example (B), AV
An example of setting r is shown in (C). Alternatively, the parameter characteristic of the degree of danger can be determined by changing the weighting coefficient of each parameter.

Subsequently, the preceding vehicle danger degree calculation step S3
3, the degree D of danger of the vehicle 103 ahead of the preceding vehicle 102
D2 (n) is calculated from the following equation.

DD2 (n) = DTdiff + kdvr × Dvr + kdar × Dar + kdd × DD2 (n-1) (7) Meanwhile, the brake is turned on In the ON / OFF determination step S51, it is determined whether or not the driver is operating the foot brake. If the driver is performing a brake operation when the degree of danger is high, it can be determined that the driver is taking avoidance action.

Next, the step S52 of calculating the degree of deceleration of the own vehicle.
Then, the deceleration of the own vehicle is calculated. When the degree of danger is high due to the above-mentioned braking operation or other deceleration means, the risk avoidance action amount indicating how much the driver is decelerating is calculated. The degree Avdec (n) of the vehicle deceleration is calculated by the following equation.

[0072]   Avdec (n) = (Vp (n) -Vp (n-1)) / τ ... (8) Vp (n): Own vehicle speed at the current time Vp (n-1): Own vehicle speed at the previous time τ: time Also, the collision avoidance action amount is calculated by the following equation.

AAdeg (n) = kabrk × Abrk + kvdec × Avdec · (9) AAdeg (n): Current collision avoidance behavior amount Kabrk: Weighting coefficient Abrk: Brake ON / OFF signal Kvdec: Weighting coefficient Avdec: Deceleration degree In step S34 of calculating the overall degree of danger of the preceding vehicle, step S
32, the total degree of danger DD12 of the preceding vehicle relative to the own vehicle based on the preceding vehicle and the preceding vehicle risk degree calculated in S33 and the risk avoidance action amount obtained in steps S51 and S52.
(N) is calculated by the following formula.

[0074]   DD12 (n) = kdd1 × DD1 (n) + kdd2 × dd2 (N) + kdd 12 × DD12 (n-1) + kaa × AAdeg ... (10) Kdd1> Kdd2.

Kdd1: weight coefficient Kdd2: weight coefficient Kdd12: weight coefficient Kaa: weight coefficient Return to step S3 shown in FIG.
Based on D12 (n), whether to warn the driver with an alarm is determined by the following formula.

DD12 (n)> WARNth (11) When the expression 11 is satisfied, the driver is warned by an alarm. Further, by classifying the warning levels according to the level of the total risk of the preceding vehicle DD12 (n) and warning and warning the driver in stages, a more appropriate danger warning can be provided to the driver. For example, if classified into three stages, the following determination patterns are possible.

DD12 (n)> WARNth1 DD12 (n)> WARNth2 DD12 (n)> WARNth3 WARNth1>WARNth2> WARNth3 As described above with reference to the embodiments of the present invention, the vehicle radar device of the present embodiment. Can make a flexible response to road traffic conditions by not only warning the preceding vehicle but also monitoring the vehicle ahead of the preceding vehicle.

In the case where the vehicle is continuously traveling on the lane on a highway or the like (Platoon traveling), a sudden collision with one vehicle causes a collision accident. This is probably because each vehicle does not maintain the safe inter-vehicle distance, or each vehicle cannot cope with sudden sudden deceleration while maintaining the safe inter-vehicle distance. In such a situation, by not only targeting the preceding vehicle as an alarm target but also monitoring the vehicle ahead of the preceding vehicle, the danger of a rear-end collision with the preceding vehicle can be detected promptly, so a system with higher safety is configured. can do.

Further, it is possible to obtain a high commercial value as compared with the conventional vehicle radar device.

In an application such as an automatic vehicle control system (ACC), a high-performance and stable ACC can be taken because safety measures such as sudden deceleration of the controlled vehicle can be detected quickly and a margin can be added to the inter-vehicle distance. Can be provided.

[0081]

As described above, the radar device for a vehicle and the method for warning a degree of danger thereof according to the present invention are radars which receive a reflected wave from a target of a transmission signal, mix it with the transmission signal, and output a beat signal. The preceding vehicle and the preceding vehicle are captured and identified from the head and a plurality of targets, and the degree of danger of the preceding vehicle to the own vehicle and the degree of danger of the preceding vehicle to the preceding vehicle are comprehensively determined from the degree of danger to the preceding vehicle. Equipped with a preceding vehicle warning means that issues a warning to the driver in a stepwise manner, and not only targets the preceding vehicle as an alarm target but also monitors the vehicle ahead of the preceding vehicle, thereby promptly detecting the risk of a rear-end collision with the preceding vehicle. Since it can be detected, there is an effect that a system with higher safety can be configured.

Further, there is an effect that higher commercial value can be obtained as compared with the conventional vehicular radar device and the conventional warning method of the degree of danger.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle radar device of the present invention.

FIG. 2 is a block diagram showing a configuration example of a danger warning unit in FIG.

FIG. 3 is a flowchart showing a danger degree warning method that is an overall operation of a preceding vehicle warning unit in the vehicle radar device of the present embodiment.

FIG. 4 is a flowchart showing each processing flow of a target recognition processing step and a yaw rate sensor processing step of FIG.

5 is a flowchart showing each processing flow of a danger warning processing step and a collision avoidance action processing step of FIG.

FIG. 6 is an explanatory diagram showing how a preceding vehicle is recognized on a straight road and a curved road, respectively.

FIG. 7 is an explanatory diagram showing an example of detection characteristics of a preceding vehicle and a preceding vehicle on a straight road.

FIG. 8 is a graph showing an example of parameter setting for calculating the degree of danger DD1 (n).

[Explanation of symbols]

1 radar head 2 LPF 3 amplifier 4 A / D converter 5 Target processing unit 6 Yaw rate sensor 7 Radius estimator 8 Own vehicle trajectory estimator 9 Danger warning section 10 preceding vehicle alarm 51 Frequency analysis processor 52 target detector 53 Leading vehicle recognizer 54 Forward car recognizer 91 Leading vehicle hazard warning judge 92 Forward vehicle danger alarm judgment device 93 Preceding vehicle danger level judgment device 94 Alarm equipment 95 Brake ON / OFF judgment device 96 own vehicle deceleration degree determiner 97 Collision avoidance action amount judgment device 101 own vehicle 102 preceding vehicle 103 forward car

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G08G 1/16 G08G 1/16 C

Claims (10)

[Claims] 1. A vehicle for detecting a distance between a vehicle and a target which is an obstacle and a relative speed of the target by using a radio signal to obtain a degree of danger of the target to the vehicle and issuing a warning to a driver. In a radar device for use, a radar head that transmits the radio wave signal as a transmission signal, receives a reflected wave from the target, mixes with the transmission signal to output a beat signal, and processes the beat signal to process a plurality of the radar signals. From the target, the preceding vehicle which is the vehicle on the own lane closest to the own vehicle and the front vehicle which is the vehicle on the own lane closest to the preceding vehicle located in front of the preceding vehicle are captured and identified, and The risk level of the preceding vehicle with respect to the own vehicle is comprehensively determined stepwise from the risk level of the preceding vehicle with respect to the own vehicle and the risk level of the preceding vehicle with respect to the preceding vehicle. And a preceding vehicle warning means for issuing the warning to the driver, wherein the preceding vehicle warning means performs a frequency analysis of the beat signal to detect a plurality of the targets from a frequency spectrum associated with the target, and a plurality of the targets. Target processing means for capturing and identifying the preceding vehicle and the preceding vehicle from among, and calculating a first risk degree of the preceding vehicle with respect to the own vehicle and a second risk degree of the preceding vehicle with respect to the preceding vehicle,
For a vehicle characterized by further comprising: a danger warning unit that comprehensively obtains the danger level of the preceding vehicle with respect to the own vehicle in stages from the first and second danger levels and issues the warning to the driver. Radar equipment. 2. The radar device for a vehicle according to claim 1, wherein the radar head includes an FMCW radar in which a millimeter wave band continuous wave is subjected to frequency modulation of a triangular wave. 3. A vehicle which uses a radio signal to detect the distance between the vehicle and a target that is an obstacle and the relative speed of the target to determine the degree of danger of the target to the vehicle and issue a warning to the driver. Radar device for FMC, which performs frequency modulation of continuous wave of millimeter wave band with triangular wave
A radar head that transmits the radio wave signal that is a W signal as a transmission signal, receives a reflected wave from the target, mixes with the transmission signal, and outputs a beat signal, and a low-pass beat that removes high-frequency components of the beat signal. A low-pass filter that outputs a signal; an amplifier that amplifies the low-pass beat signal and outputs an amplified beat signal; and a plurality of targets that perform information processing of a digital beat signal obtained by analog-digital (A / D) converting the amplified beat signal. The preceding vehicle which is the vehicle on the own lane closest to the own vehicle and the preceding vehicle which is the vehicle on the own lane closest to the preceding vehicle located in front of the preceding vehicle are captured and identified from among Based on the degree of danger of the vehicle to the own vehicle and the degree of danger of the preceding vehicle to the preceding vehicle, The preceding vehicle warning unit that issues the warning to the driver by stepwise obtaining the degree of danger, and a yaw rate sensor that measures the angular velocity of the vehicle on a curved road and outputs the angular velocity value, An A / D converter that A / D-converts the amplified beat signal and outputs the digital beat signal that is discrete value data of the amplified beat signal sampled at a fixed time; and an A / D converter that processes the digital beat signal. A target processing unit that outputs target information including the distance and relative speed of the preceding vehicle to the vehicle and recognition of the preceding vehicle and the preceding vehicle, and a radius estimator that calculates a road radius from the angular velocity value obtained from the yaw rate sensor. A vehicle trajectory estimator that calculates a vehicle trajectory that is a trajectory of the vehicle based on the road radius; and the target Vehicle radar apparatus, characterized in that it comprises a hazard alarm unit risk for the vehicle from the target based on the target information from the management unit to determine whether a high. 4. A frequency analysis processor for extracting a spectrum from the digital beat signal using a frequency component analysis method by FFT, and a target analysis unit for extracting a spectrum from the host vehicle based on the extracted spectrum. A target detector that calculates distance speed information that is a relative speed between the distance and the vehicle, a preceding vehicle recognizer that recognizes the preceding vehicle based on the distance speed information and outputs preceding vehicle information, and the distance speed information The vehicle radar device according to claim 3, further comprising a front vehicle recognizer that recognizes the front vehicle based on the above and outputs front vehicle information. 5. The preceding vehicle danger warning determination in which the danger warning unit calculates a degree of danger of the preceding vehicle with respect to the own vehicle based on the preceding vehicle information and the preceding vehicle information and outputs a preceding vehicle danger level determination signal. And a forward vehicle danger warning determiner that calculates the degree of danger of the preceding vehicle with respect to the preceding vehicle and outputs a forward vehicle risk determination signal, the preceding vehicle risk determination signal, the forward vehicle risk determination signal, and And a preceding vehicle risk degree determination signal that comprehensively calculates the risk degree of the own vehicle with respect to the preceding vehicle and outputs the preceding vehicle risk degree determination signal based on the collision avoidance action amount determination signal of Based on the alarm, an alarm device that warns the driver step by step with an alarm sound, and whether or not the driver of the vehicle is performing a brake operation is determined by brake ON / OFF detection, and the determination result is obtained. Brake ON to output the brake ON / OFF judgment signal
/ OFF judging device, a vehicle deceleration degree judging device for judging how much the vehicle is decelerating by a brake operation of the own vehicle and outputting a judgment result signal for judging the own vehicle deceleration, and the brake ON / OFF judgment A collision avoidance action amount determiner that comprehensively determines how much the own vehicle is performing collision avoidance based on a signal and the own vehicle deceleration degree determination signal, and outputs a collision avoidance action amount determination signal. The vehicle radar device according to claim 3. 6. A vehicle for detecting a distance between a vehicle and a target, which is an obstacle, and a relative speed with respect to the target by using a radio signal to obtain a degree of danger of the target to the vehicle and issuing a warning to a driver. In a method of warning a degree of danger of a radar device for a vehicle, a preceding vehicle that is a vehicle on a lane closest to the own vehicle among the plurality of targets and the own vehicle closest to the preceding vehicle located in front of the preceding vehicle The front vehicle, which is a vehicle on the line, is captured and identified, and the danger level of the preceding vehicle with respect to the own vehicle is comprehensively determined based on the risk degree of the preceding vehicle with respect to the own vehicle and the danger degree of the preceding vehicle with respect to the preceding vehicle. And a warning degree to the driver, the warning degree being issued to the driver. 7. The danger level warning method for a vehicle radar device according to claim 6, wherein the radio signal is an FMCW signal obtained by subjecting a continuous wave in a millimeter wave band to frequency modulation of a triangular wave. 8. A distance between a host vehicle and a target that is an obstacle and a relative speed between the target and the target are detected by using an FMCW signal obtained by frequency-modulating a continuous wave of a millimeter wave band into a triangular wave to detect the target of the target. A method for alerting a vehicle radar device of a degree of danger to a vehicle and warning the driver, the method comprising: mixing a transmission signal, which is the FMCW signal, and a reception signal, which is a reflected wave received from the target. The digital beat signals corresponding to the rising and falling sections (hereinafter referred to as the upper and lower sections) of the triangular wave generated by A / D conversion of the beat signal are frequency-analyzed to obtain the spectrum of the upper and lower sections. Find the distance and relative velocity of each peak pair that pairs the corresponding peaks of all peaks, and then perform the yaw rate sensor processing step described below. Using the calculated own vehicle trajectory in combination, a target on the own lane is selected, and a preceding vehicle which is a vehicle on the own lane closest to the own vehicle from among the plurality of targets on the own lane and this A target recognition processing step of recognizing a preceding vehicle that is a vehicle on the lane closest to the preceding vehicle located in front of the preceding vehicle and outputting corresponding preceding vehicle information EC and preceding vehicle information ED; Based on the vehicle information and the preceding vehicle information, the degree of danger of the preceding vehicle with respect to the own vehicle is calculated to generate a preceding vehicle risk determination signal, and the degree of danger of the preceding vehicle with respect to the preceding vehicle is calculated to determine the preceding vehicle danger. Of the preceding vehicle danger level determination signal, the preceding vehicle risk level determination signal, and the collision avoidance action amount determination signal calculated in the collision avoidance action processing step described later, to generate the overall own vehicle. The preceding vehicle to calculate the degree danger outputs preceding vehicle danger about determination signal to,
If it is determined from the preceding vehicle risk level determination signal that the risk level is high, a risk determination processing step that alerts the driver with an alarm display and a yaw rate sensor output based on the angular velocity output from the host vehicle A yaw rate sensor processing step of calculating a road radius along with the speed information, calculating a host vehicle trajectory which is a road trajectory traveling from the present time onward from the road radius, and supplying the host vehicle trajectory to the target recognition processing step; Brake O to see if the car brake was operated
This brake ON / O is judged by the N / OFF judgment signal.
The collision avoidance action amount of how much the own vehicle is performing collision avoidance is calculated by the own vehicle deceleration degree determination signal, which is the determination result of the deceleration degree by the deceleration means including the brake ON / OFF based on the FF determination signal, A collision avoidance action processing step of outputting a collision avoidance action amount and supplying the collision avoidance action amount to the risk determination processing step. 9. The target recognition processing step performs AD conversion of the beat signal in the upper and lower sections to generate the digital beat signal in the upper and lower sections, and an AD conversion step in the upper and lower sections of the digital beat signal. Upper and lower section frequency analysis step of outputting the spectrum by spectrum conversion by frequency analysis for each, detecting all peaks of the upper and lower sections from the spectrum,
An upper / lower section peak pairing step of pairing the detected corresponding peaks of the upper and lower sections with each other to generate a peak pair, and obtaining a distance and a relative speed of each peak pair for all the peak pairs of the upper and lower sections. A distance / relative speed calculation step, a target lane target selection step for extracting a target on the own lane based on the own vehicle trajectory estimated in the own vehicle trajectory estimation calculation step described later, and a target selection step on the own lane The preceding vehicle recognition step of recognizing the vehicle closest to the own vehicle as the preceding vehicle from the targets on the own lane selected in step 1, and the preceding vehicle from the targets on the own lane selected in the preceding vehicle recognition step A front vehicle recognizing step for recognizing a vehicle closest to the front vehicle as a front vehicle. , AD conversion of the angular velocity from the yaw rate sensor to generate a digital angular velocity, a road radius estimation calculation step of calculating a road radius from the digital angular velocity, and a road radius estimation calculation step. The vehicle radar apparatus according to claim 8, further comprising: a vehicle trajectory estimation calculation step of estimating the vehicle trajectory, which is a road trajectory of the vehicle traveling after the present time based on the determined road radius. Degree warning method. 10. A relative acceleration calculation step of calculating a relative acceleration of the preceding vehicle with respect to the own vehicle and a relative acceleration of the preceding vehicle with respect to the preceding vehicle in the risk determination processing step, and the relative acceleration of the preceding vehicle with respect to the own vehicle. A preceding vehicle risk degree calculating step for calculating a preceding vehicle risk degree which is a dangerous degree, a forward vehicle risk degree calculating step for calculating a forward vehicle risk degree which is a dangerous degree of the preceding vehicle with respect to the preceding vehicle, and a preceding vehicle danger degree And a preceding vehicle total risk degree calculating step of calculating a comprehensive risk degree of the preceding vehicle with respect to the own vehicle based on the preceding vehicle risk degree and a risk avoidance action amount described later, the collision avoidance action process The brake O determines whether the driver is operating the foot brake.
An N / OFF determination step, and a own vehicle deceleration degree calculation step for calculating deceleration of the own vehicle and calculating a risk avoidance action amount indicating how much the driver is decelerating when the degree of danger is high The method for warning a degree of danger of a vehicle radar device according to claim 8.