JP2001202599A - Radar wave repeater for reporting approach and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radar wave repeater reporting approach and a display device which are inexpensive and small-sized and can securely prevent the collision of the vehicles (mobile objects) the moment they reach the blind crossing without mistaking a stopping vehicle for an entering vehicle and whose failure rate is low. SOLUTION: A radar wave from a radar device loaded on the mobile object is received by a radar wave reception part 16A. The received radar wave is changed to directions (roads B to D, for example) different from the transmission source direction of the radar wave and transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar wave relay device and a display device for notifying another moving object of the presence of a moving object approaching a predetermined place, and more particularly, to a vehicle at an intersection with poor visibility. The present invention relates to a radar wave relay device and a display device for approach notification, which are preferably used to prevent a collision at an intersection.

[0002]

2. Description of the Related Art As a method of notifying a vehicle approaching an intersection with poor visibility that there is an approaching vehicle from another direction, for example, a method using a curved mirror (convex mirror) or a method disclosed in Japanese Unexamined Patent Publication No.
As proposed in, for example, Japanese Patent Publication No. 106600, a sensor such as an ultrasonic wave, a light beam, or an infrared ray is installed in front of an intersection to detect the presence of an approaching vehicle, and to detect the approaching vehicle at a position where the driver (driver) can easily see it. There is a method of displaying on an installed display device.

[0003]

However, in the former method using a curved mirror, depending on the positional relationship between a curve mirror and a person entering an intersection or a car, there may be a blind spot that may not be visible, or the direction due to wind may be reduced. Misalignment is likely to occur. Further, it may be difficult to visually recognize the curve mirror itself under bad weather conditions such as rain and fog.

On the other hand, in the latter method, the speed of the approaching vehicle cannot be measured, even if the presence of the approaching vehicle is known. For this reason, if there is a parked vehicle near the intersection, it will be erroneously recognized as an approaching vehicle. In order to avoid this, for example, a plurality of the above-mentioned sensors are installed in a row at a distance near an intersection, and the vehicle 2 between these sensors is installed.
Although it is conceivable to measure the transit time, it requires a great deal of effort to secure a place for installing the sensor and to perform a construction work, and furthermore, a large-scale and complicated system configuration is required.

As a typical method for preventing collision of a moving object such as a vehicle, a millimeter-wave radar is mounted on the vehicle, and the presence of a forward obstacle (vehicle) is determined based on the reflected wave of the millimeter-wave radar. There is a method of notifying the driver, but this method has a strong directivity of millimeter waves,
It is not possible to detect the presence of a vehicle entering the intersection from another direction.

Therefore, as shown in, for example, JP-A-5-20599 and JP-A-7-1055500, a detection device (radar) is installed at the intersection to detect a vehicle approaching the intersection. It is conceivable that when an approaching vehicle is detected, a warning light or an indicator may be used to notify the driver in directions other than the direction to the vehicle. Since a function (power supply or transmitter) for transmitting a radar wave is required in the detection device installed in the device, the size of the device is increased, the rate of occurrence of failures is increased, and the maintenance work associated therewith is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. For example, a collision of a vehicle (moving object) at an intersection with poor visibility, etc., may be mistaken for a stopped vehicle as an approaching vehicle. An object of the present invention is to provide a radar wave relay device and a display device for approach notification that can be reliably prevented and have a low failure rate and that are small and inexpensive.

[0008]

In order to achieve the above object, a radar wave relay device for approach notification according to the present invention (Claim 1) includes a radar wave receiving unit for receiving a radar wave from a moving object. And a receiving radar wave transmission direction changing unit capable of changing and transmitting a radar wave received by the radar wave receiving unit in a direction different from the direction in which the radar wave was transmitted. I have.

Here, the present radar wave relay device (hereinafter, also simply referred to as “relay device”) further includes, in addition to the above configuration, a reflection of the radar wave transmitted from the reception radar wave transmission direction changing unit. A reflected wave receiving unit that receives a wave and a reflected wave transmitting unit that transmits the reflected wave received by the reflected wave receiving unit toward the moving object may be provided.

[0010] The receiving radar wave transmission direction changing unit may include a polarization plane conversion unit for converting the polarization plane of the radar wave received by the radar wave receiving unit to a different polarization plane. Claim 3). Further, the relay apparatus adjusts a delay time from when the pulse wave is received by the radar wave receiving unit to when a reflected wave of the pulse wave is transmitted from the reflected wave transmitting unit. A delay adjuster may be provided (claim 4).

[0011] Further, a radar wave relay device for approach notification according to the present invention (Claim 5) is a radar wave receiver for receiving a radar wave from a moving object, and a radar wave received by the radar wave receiver. A return transmission unit that transmits the return signal toward the moving object, a reflected wave reception unit that receives a reflected wave of the return radar wave transmitted from the return transmission unit on the moving object, and the return radar wave. A speed information detecting unit for detecting speed information of the moving object from the reflected wave, and receiving speed information detected by the speed information detecting unit from another direction different from the direction in which the radar wave was transmitted. And a speed information addition transmission unit for transmitting the radar wave to the other direction in addition to the radar wave.

[0012] Next, the approach notification display device of the present invention (claim 6) can change the direction of a radar wave received from a moving object to a direction different from the direction in which the radar wave was transmitted, and transmit it. A relay radar wave receiving unit that receives a relay radar wave relayed by the radar wave relay device, and a speed information detecting unit that detects speed information of a moving object from the relay radar wave received by the relay radar wave receiving unit, The speed information detecting section is provided with a display section for displaying the speed information detected by the speed information detecting section.

Here, the present display device provides a speed information mask which supplies the speed information to the display unit only when the speed information detected by the speed information detection unit is equal to or higher than a predetermined threshold value. A part may be provided (claim 7). Further, the relay radar wave receiving section includes a polarization plane identification section for identifying the polarization plane of the radar wave received from the radar wave relay apparatus, and the display section identifies the polarization plane by the polarization plane identification section. It may be configured to display information on the moving direction of the moving object according to the determined polarization plane (claim 8).

Further, a display device for approach notification according to the present invention (claim 9) is a light emitting portion for displaying the presence of a moving object, which emits light to indicate the presence of a moving object, and a light emitting color according to speed information of the moving object. Alternatively, a light emitting unit for displaying speed information in which a light emitting state changes is provided. Further, a display device for approach notification according to the present invention (Claim 10)
Is a point display area for displaying information about a point at which a moving object can enter, and in this point display area, the presence and the moving direction of the moving object are illuminated and displayed, and the moving speed of the moving object is It is characterized by having a light-emitting portion for displaying a direction / speed in which a light-emitting color or a light-emitting state changes accordingly.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) Description of First Embodiment FIG. 1 is a schematic diagram for explaining a collision prevention system to which an approach notification radar wave relay device according to a first embodiment of the present invention is applied. In the collision prevention system shown in FIG. 1, in the radar wave relay device 1 installed at the center of the intersection of the roads A to D, the collision prevention system mounted on the vehicle (moving object) 2 entering the intersection is mounted. Radar [for example, CW
(Continuous Wave) radar)
Directions (roads) other than the direction from which the radar wave was transmitted
Re-radiation (relay transmission) is performed. The “anti-collision radar” is defined as a frequency shift (Doppler shift) caused by the Doppler effect between the own transmitted radar wave and a reflected wave of the transmitted radar wave reflected by an obstacle such as another vehicle 2. It is possible to detect the presence of an obstacle having a speed ahead of the object 2.

For this reason, the radar wave relay device (hereinafter simply referred to as “relay device” or “repeater”) 1 of the present embodiment is, for example, as shown in FIG. Receiving antennas 11A to 11D, distributors 12A to 1
2D, synthesizers 13A to 13D, circulator 14A to
14D, polarization plane converters 15A to 15D, and transmission antennas 16A to 16D. In the following, when the directions of the roads A to D of these components are not particularly distinguished, the symbols A to D are abbreviated as the reception antenna 11, the distributor 12, and the like.

Here, the receiving antenna (radar wave receiving unit)
11A to 11D are for receiving radar waves (hereinafter, also referred to as vehicle-mounted radar waves) transmitted from the vehicle 2 entering the roads A to D toward the intersections, respectively. Reference numeral 12D is for dividing the radar waves received by the corresponding receiving antennas 11A to 11D into three, and outputting the three to the combiner 13 for the other three directions except for the road direction in which the radar waves are assigned.

The combiners 13A to 13D combine three systems of received radar waves distributed from the road direction distributor 12 except for the road direction distributor 12 which is in charge of each of them. And the circulators 14A-1
4D allows only the radar waves synthesized by the corresponding synthesizers 13A to 13D to pass, respectively, so that the radar waves received by the reception antenna 11 for the same road direction do not enter the transmission antenna 16 side. belongs to.

Further, the polarization plane converters 15A to 15D are
Each is for rotating the polarization plane of the radar wave from the corresponding circulator 14 by 90 °.
It can be realized by a twisted waveguide as shown in FIG. Then, the transmitting antennas 16A to 16D
Are respectively the polarization plane converters 15A in the directions of the roads A to D.
It re-radiates the radar wave after the polarization plane conversion by 15D.

That is, the distributor 12 and the synthesizer 13,
The portion including the circulator 14, the polarization converter 15, and the transmitting antenna 16 is configured to transmit the on-vehicle radar wave received by the receiving antenna 11 in a direction (1) different from the original direction (the direction in which the on-vehicle radar wave was transmitted). The direction functions as a receiving radar wave transmitting direction changing unit that can change and transmit (relay) the received radar wave.

As described above, the relay device 1 of the present embodiment
In order to re-emit a received radar wave to a road direction other than the direction in which the radar wave was sent, it can be configured without using an active circuit such as a transmitter or a power supply. By the way, as described above, it is necessary to rotate the plane of polarization of the received radar wave and re-emit it.
This is because the plane of polarization is inclined to avoid interference with radar waves from oncoming vehicles. That is, for example, if the polarization plane of the linear polarization of the transmission radar wave is tilted at 45 °, the difference between the reception polarization planes of the own vehicle and the oncoming vehicle becomes 90 °, and the orthogonality is obtained. If the reception radar wave having the tilted polarization plane is relayed as it is (without changing the polarization plane) in the relay device 1, the vehicle 2 where the relay radar wave is to be received has the same reception polarization plane as the own vehicle 2. Since the polarization plane of the relay radar wave is orthogonal, the relay radar wave cannot be received.

Therefore, in the present embodiment, as described above, when the radar wave is re-emitted from the relay apparatus 1, the polarization plane converters (polarization plane conversion units) 15A to 15D use the polarization planes of the received radar waves. Is rotated by 90 ° so that the transmission polarization plane when viewed from the road side is the same as the reception polarization plane. That is, the polarization plane of the received radar wave is converted to a polarization plane different from the original polarization plane.

For example, when the transmission polarization plane and the reception polarization plane of each vehicle 2 are inclined rightward (45 °),
As shown in FIGS. 4A and 4B, each of the roads A to D
By rotating the polarization plane of the reception radar wave from the direction (upward to the right as viewed from the roads A to D) by 90 °, the transmission polarization plane and the reception polarization plane when the repeater 1 is viewed from each of the roads A to D. Also tilt up to the right.

Thereby, for example, the vehicle 2A shown in FIG.
Focusing on the radar wave, as shown by the alternate long and short dash line 3 in FIG. 4B, the radar wave arriving from the opposite direction (the direction of the road C) without passing through the repeater 1 has a different polarization plane. 2A) is not received as a reflected wave of the transmitted radar wave, but the radar wave arriving via the repeater 1 has its polarization plane converted to the same as the reception polarization plane of its own vehicle 2A. It becomes possible to receive as a reflected wave of the radar wave transmitted by the own vehicle 2A.

Hereinafter, the operation of the collision prevention system having the repeater 1 will be described in detail. For example, in FIG. 1, it is assumed that vehicles 2A and 2B enter the intersection from roads A and B, respectively. In this case, the radar wave transmitted from the collision prevention radar mounted on the vehicle 2A is received by the receiving antenna 11A of the relay device 1, is divided into three by the distributor 12A, and then is divided into roads B to D other than the road A. Combiner 13 for direction
B to 13D and input to the polarization plane converters 15B to 15D via the circulators 14B to 14D.

The reception radar waves whose polarization planes are rotated by 90 ° in the polarization plane converters 15B to 15D are re-emitted from the transmitting antennas 16B to 16D to the roads BD. Here, the frequency of the transmission radar wave (transmission frequency) of the vehicle 2A = fa '[Hz], and the speed of the vehicle 2A = va'.
[M / s], the vehicle 2A viewed from the relay device 1
From the equation of the Doppler effect, the frequency fa ′ of the radar wave from

[0027]

(Equation 1)

## EQU1 ## However, in this equation (1),
c represents the speed of light. Therefore, road B, road C and road D
In each direction, a radar wave of frequency fa 'will be re-emitted. Therefore, a radar wave having a frequency fa 'that matches the reception polarization plane of the vehicle 2B (hereinafter, also referred to as a radar wave fa') arrives at the vehicle 2B. Here, the transmission frequency of the radar wave of the vehicle 2B = fb [Hz],
Assuming that the speed of the vehicle 2B = vb [m / s], this radar wave
The frequency fa ' _{(b) as} viewed from the vehicle 2B of fa' is given by the Doppler effect equation.

[0029]

(Equation 2)

## EQU1 ## If this is compared with the frequency fb of the radar wave transmitted by the in-vehicle radar of the vehicle 2B,
From the expression of the Doppler effect, the relative speed vab between the vehicle 2A and the vehicle 2B is obtained as follows.

[0031]

(Equation 3)

Thus, in the vehicle 2B, it appears as if there is an obstacle having the speed vab in the direction (near the intersection) of the intersection, and the driver of the vehicle 2B can be alerted. At present, the center frequency of the on-vehicle radar practically used in Japan is almost the same (approximately 59.5 GHz). In this case, the relative speed vab between the vehicle 2A and the vehicle 2B determined by the above equation (3) is slightly different from the actual relative speed. However, it is possible to obtain accurate speed information to some extent.

Similarly, the radar wave transmitted from the vehicle 2B is re-emitted in the direction of the road A after the polarization plane is rotated by 90 ° by the relay device 1, and the radar wave is transmitted to the vehicle 2B.
By receiving A, the vehicle 2A looks as if there is an obstacle (vehicle 2B) having the speed vab in the direction of the intersection (near). As described above, the driver of each of the vehicles 2A and 2B entering the intersection can be notified of the presence (approach) of the vehicles 2B and 2A entering from the other direction to alert the driver, and the driver can meet the driver at the intersection. Collisions can be avoided or prevented beforehand.

It should be noted that, even when there is an approaching vehicle 2 from the road C or the road D, the driver can be alerted in the same manner as described above. In addition, how to alert the driver (notification method) may be performed by an audible means such as an alarm sound or a visual means such as an alarm display. Further, the vehicle speed may be automatically controlled to be reduced with or without the notification. This makes it possible to more reliably prevent a collision accident at an intersection.

As described above, according to the collision prevention system (relay device 1) of the present embodiment, by merely installing the above-described relay device 1 at the intersection, the existing vehicle-mounted radar is utilized as it is, and the vehicle at the intersection is used. 2 can reliably prevent a collision accident at the meeting. In particular, in the present embodiment, not only the presence or absence of the approaching vehicle 2 but also the speed information of the approaching vehicle 2 can be detected, so that the stopped vehicle 2 may be erroneously recognized as the approaching vehicle 2. There is no. In addition, since the radar wave is used, it is not affected by the weather or the like.

Further, the relay device 1 according to the present embodiment
Therefore, as described above, since all the circuits can be configured by passive circuits without using active circuits such as a transmitter and a power supply circuit, it is possible to greatly reduce the size and cost. In addition, in this case, there is no need to supply power, so installation is easy, and the failure rate can be greatly reduced compared to the case where a transmitter and a power supply circuit are provided. Can be reduced. In order to extend the measurement (detection) distance, the output (transmission power level) of the on-vehicle radar can be appropriately increased or an amplifier can be provided.

(B) Description of Second Embodiment FIG. 5 is a schematic diagram for explaining a collision prevention system to which a radar wave relay device for approach notification according to a second embodiment of the present invention is applied. In the collision prevention system shown in FIG. 5, in the radar wave relay device 1A installed at the center of the intersection of the roads A to D, the collision prevention radar (for example, CW radar) mounted on the vehicle 2 approaching the intersection is installed. Is returned to the vehicle 2 that transmitted the radar wave, and the reflected wave is received, the speed information of the vehicle 2 is detected, and the speed information is mounted on the vehicle 2 that enters the intersection from another direction. The vehicle is mounted on a radar wave of the radar and turned back to the vehicle 2.

For this reason, the relay device 1A of the second embodiment
Is, for example, as shown in FIG.
As receiving antennas 21A and 25A, transmitting antenna 2
3A, 30A, distributors 22A, 27A, directional coupler 2
4A and mixers 26A and 29A, and the receiving antenna 2
1B, 25B, transmitting antennas 23B, 30B, distributor 2
2B, 27B, directional coupler 24B and mixers 26B, 2
9B.

Although not shown in FIG. 6, the road C direction circuit and the road D direction circuit have the same configuration as the road A direction circuit 10A and the road B direction circuit 10B. It is assumed that a circuit is also provided. Hereinafter, for convenience, the circuit for the road C direction is denoted by reference numeral 10C, and the circuit for the road D direction is denoted by reference numeral 10D. In the following, when the distinction is not made between the directions of the roads A to D, the notation of English characters such as A and B may be omitted, such as the reception antenna 21 and the transmission antenna 23.

The circuit 1 for each of the roads A to D described above.
In 0A to 10D, a receiving antenna (radar wave receiving unit) 21 is for receiving a radar wave from a vehicle-mounted radar of the vehicle 2 entering the intersection from the roads A to D, and a distributor 22. Divides the radar wave received by the reception antenna 21 into two, one of which is turned back to the same road direction through the transmission antenna 23, and the other is input to the mixer 22A. That is,
The transmission antenna 23 functions as a return transmission unit that returns the in-vehicle radar wave received by the reception antenna 21 to the same road side.

The directional coupler 24 is for extracting a part of the reception radar wave that is turned back through the transmission antenna 23, and receives the reception antenna (reflected wave reception unit) 2
Numeral 5 is for receiving the reflected wave of the radar wave returned and transmitted by the transmission antenna 23. The mixer 26 is configured to receive the reflected wave of the folded radar wave received by the reception antenna 25 and the directional coupler. By mixing the return radar wave extracted in 24 with the return radar wave, frequency difference information between the return radar wave and its reflected wave is detected.

Here, since this frequency difference information is generated by the Doppler effect according to the moving speed of the vehicle 2A, it includes the speed information of the vehicle 2A.
That is, the mixer 26 functions as a speed information detection unit that detects speed information for detecting speed information of the vehicle 2 from the return radar wave and the reflected wave, and includes the transmission antenna 23 and the directional coupler 24. , The receiving antenna 25, and the mixer 26 function as a radar that detects the speed of the vehicle 2 from the difference between the transmission frequency and the reflection frequency without using a transmitter or the like.

The distributor 27 divides the signal (frequency difference information) obtained by the mixer 26 into three parts and distributes them to the circuit 10 for the road direction in the other direction. The mixer 29 combines the three signals distributed from the distributor 27 of the circuit 10 for the other direction with the output of the combiner 28 and the reception radar distributed from the distributor 22. The frequency difference information is added to the received radar wave by mixing the received radar wave.

The transmitting antenna 30 is connected to the mixer 2
The output of No. 9 is transmitted to the vehicle 2 entering the intersection from the direction of the road in charge (for example, the direction of the road A for the transmitting antenna 30A, the direction of the road B for the transmitting antenna 30B). That is, the mixer 29 and the transmitting antenna 30 add the velocity information detected by the mixer 26 to the on-vehicle radar wave received from another direction different from the direction in which the on-vehicle radar wave is transmitted, and add the information to the direction. It functions as a speed information additional transmission unit for transmission.

Hereinafter, the operation of the collision prevention system (relay device 1A) of the second embodiment configured as described above will be described in detail. For example, also in this case, as shown in FIG.
It is assumed that the vehicles 2A and 2B enter the intersection on the roads A and B, respectively. The speed of the vehicle 2A = va, the transmission frequency of the radar wave of the vehicle 2A = fa,
It is assumed that the speed of B = vb and the transmission frequency of the radar wave of the vehicle 2B = fb.

At this time, the radar wave (frequency fa) radiated from the on-vehicle radar of the vehicle 2A (speed va) is obtained from the above equation (1) by the reception antenna 21A of the repeater 1 at the frequency fa '. (Hereinafter, sometimes referred to as a radar wave fa '). This received radar wave fa '
It is turned back inside the relay device 1 and re-emitted from the transmitting antenna 23A toward the vehicle 2A. The radar wave (reflected wave) returned by the reflected radar wave (frequency fa ') reflected by the vehicle 2A is represented by the frequency fa "[fa" is obtained by the above equation (1).
Is a value obtained by substituting fa ′ into fa))].
A receives it.

The reflected wave (frequency fa ″) received by the receiving antenna 25A is converted by the mixer 26A into a folded radar wave (frequency) extracted by the directional coupler 24A.
fa '). As a result, the frequency difference information (velocity data) between these reflected waves and the folded radar waves
Δfa (= fa ″ −fa ′ = fa′−fa) is obtained.This frequency difference information Δfa is divided into three by the distributor 27A, and is combined with the other road B to D direction circuits 10B to 10D. 28.

Attention is paid to the road B direction circuit 10B. In this road B direction circuit 10B, the frequency error information Δfa input from the distributor 27A of the road A direction circuit 10 and the other Road direction circuits 10C, 10D
And the frequency error information (in the case where there is no approaching vehicle 2) input in the same manner, is synthesized by the synthesizer 28 B, and is input to the mixer 29 B.

The mixer 29B mixes the output of the synthesizer 28B with the radar wave from the vehicle 2B received by the receiving antenna 21B to produce a radar wave (frequency fb ') from the vehicle 2B. The frequency difference information Δfa obtained as described above based on the reception radar wave from 2A is added, and this (fb ′ + Δfa) is used as the transmission antenna 30.
B is re-emitted to the vehicle 2B. Note that the frequency fb 'is obtained in the same manner as the frequency fa' [see equation (1)].

When the vehicle 2B receives the radar wave of the frequency fb '+ Δfa from the relay apparatus 1A, the frequency difference information Δfa
Is extracted, the speed va of the vehicle 2A can be obtained, whereby the vehicle 2A entering the intersection at the speed va can be obtained.
The presence of A can be reported to the driver to call attention.
Similarly to the above, the driver is notified that the vehicle 2B is entering the intersection at the speed vb in the vehicle 2A.

Therefore, according to the present embodiment, the vehicle 2
A collision accident at the intersection of A and 2B can be reliably prevented, and the speed of the approaching vehicle 2 can be mutually known, so that the stopped vehicle 2 is erroneously recognized as the approaching (approaching) vehicle 2. Nothing to do. In particular, in this case, the speed information (frequency difference information) of the approaching vehicle 2 is obtained by the relay device 1, and the obtained information is placed on the radar wave of the vehicle 2 from another direction and re-emitted. Frequency) ≠ fb
Even if it is (the transmission frequency of the vehicle 2B), an accurate speed can be obtained. That is, it is possible to detect the accurate speed of the opponent vehicle 2 irrespective of the frequency or the frequency stability of the on-board radar of the opponent vehicle 2.

When there are vehicles 2 entering from roads C and D, Δfc and Δfd are added to the radar waves to vehicles 2B and 2A by combiners 28A and 28B in the same manner as described above. Therefore, the vehicles 2A and 2B respectively have Δf
By extracting c and Δfd, the presence and accurate vehicle speed can be detected. Further, for the vehicle 2 traveling on the roads C and D, the existence of the vehicle 2 entering the intersection from another direction and the accurate vehicle speed can be detected in the same manner.

Further, also in this case, the way of alerting the driver (notifying method) may be performed by an audible means such as an alarm sound or a visual means such as an alarm display.
Also, the vehicle speed may be automatically controlled to be reduced with or without this notification.
Also in the present embodiment, if it is desired to increase the measurement (detection) distance, the output (transmission power level) of the on-vehicle radar may be appropriately increased or an amplifier may be provided.

(C) Description of Third Embodiment FIG. 7 is a schematic diagram for explaining a collision prevention system to which a radar wave relay device for approach notification according to a third embodiment of the present invention is applied. In the collision prevention system shown in FIG. 7, in the relay device 1B installed in the center of the intersection, the first
Similarly to the embodiment, the radar wave of the on-vehicle radar (for example, the radar wave from the vehicle 2A) is relayed and re-emitted in each of the other intersections. , The speed information of the vehicle 2B) is included as a Doppler shift] in the direction of the source of the radar wave (the direction of the vehicle 2A).

For this reason, the relay device 1B of the third embodiment
Includes road A to D direction circuits 3A to 3D corresponding to the roads A to D, for example, as shown in FIG.
These are respectively the receiving antennas 31, 35, 37,
39, amplifier 32, distributor 33, transmitting antennas 34, 3
6, 38, 41 and a combiner 40.

Here, the receiving antenna (radar wave receiving section) 31 is for receiving a radar wave mounted on the vehicle from the direction of the road A (roads B to D), and the amplifier 32 is provided with the receiving antenna 31. Is to amplify the radar wave received at the above to a required transmission power level. The amplifier 32 is not required when a sufficient power level for relaying radar waves is secured, such as when the required measurement (detection) distance is short or when the transmission power level of the on-vehicle radar is increased. is there.

Further, the distributor 33 branches the received radar wave into three and distributes them to the transmitting antennas 34, 36 and 38, thereby changing the propagation direction of the received radar wave to the same as in the first embodiment. The transmitting antennas 34 and 3 function as a receiving radar wave transmitting direction changing unit that can change the direction to a direction different from the direction in which the vehicle-mounted radar wave is transmitted.
6, 38 respectively receive the received radar waves distributed from the distributor 33 as roads B, C,
D (Road A except road B in road B direction circuit 3B,
For transmitting (re-radiating) to the roads A, C, and D other than the road C in the circuit 3C for the direction C and D, and to the roads A to C other than the road D in the circuit 3D for the road D direction. It is.

Further, a receiving antenna (reflected wave receiving section) 3
5, 37, and 39 are the transmitting antennas 3 respectively.
The combiner 40 is for receiving the reflected wave of the radar wave re-emitted from 4, 36, 38, and the combiner 40 is for combining the reflected waves received by these receiving antennas 35, 37, 39. , The transmitting antenna (reflected wave transmitting unit) 41
The output (reflected wave) of the synthesizer 40 is output in the direction of road A (road B).
In the direction circuit 3B, the road B direction and the road C direction circuit 3C
Is transmitted in the direction of the road C and in the direction of the road D in the circuit 3D for road D directions.

However, in this case, three sets of re-radiating antennas (the transmitting antenna 3) of the road A to D direction circuits 3A to 3D are used.
4 and the receiving antenna 35 / the transmitting antenna 36 and the receiving antenna 37 / the transmitting antenna 38 and the receiving antenna 39)
Avoids interference between the road A to D direction circuits 3A to 3D (for example, the reflected wave of the re-radiated wave in the direction of the road B
For example, in order to prevent the light from being incident on the receiving antennas 31 and 37 for the direction and the direction of the road C (for example, as shown in FIG. 9), the respective (linear) polarization planes are slightly changed. FIG. 9 shows the direction of the polarization plane of the relay device 1B as viewed from the direction of the road A.

In the relay apparatus 1B according to the present embodiment configured as described above, for example, if the vehicle 2A equipped with the collision prevention radar enters from the direction of the road A toward the intersection, the transmission is performed from the vehicle 2A. Radar wave on road A
The signal is received by the receiving antenna 31 of the direction circuit 3A. The received radar wave is branched into three by a distributor 33, and roads B to D are respectively transmitted through transmitting antennas 34, 36, and 38.
Is re-emitted.

Now, as shown in FIG. 7, assuming that the vehicle 2B without the collision prevention radar enters from the road B toward the intersection, re-radiation toward the road B is performed as described above. The generated radar wave is reflected by the vehicle 2B. This reflected wave is output to the road A direction circuit 3A.
Of the other receiving antennas 3
After being synthesized with the outputs of the antennas 7 and 39 (reflected waves from the directions of the roads C and D) by the synthesizer 40, they are transmitted from the transmitting antenna 41 toward the road A (the vehicle 2A).

As a result, the vehicle 2A receives the radar wave transmitted from its own vehicle-mounted radar and relay device 1 as described above.
By comparing the frequency with the radar wave transmitted from B, the speed of vehicle 2B can be detected. As a result, the vehicle 2A enters the vehicle 2A at the intersection from another direction.
B and the speed of the approaching vehicle 2B.
Without relying on the radar wave of the vehicle 2A, the radar wave transmitted from the vehicle-mounted radar of the host vehicle 2A alone can be used, that is, regardless of the presence or absence of the vehicle-mounted radar of the approaching vehicle 2B and the difference in the radar system, the detection can be reliably performed.

Note that the vehicles 2 entering the intersection from the roads B, C, and D are also provided with the anti-collision radar in the same manner as described above, if the vehicles 2 entering from the other directions are present. It is needless to say that the vehicle speed and the vehicle speed can be detected. As described above, also in the third embodiment, the existing in-vehicle radar is utilized as it is, without being affected by the weather and the like, and the stopped vehicle 2 is not erroneously recognized as the approaching vehicle 2 at the intersection. In addition to the above, it is possible to reliably prevent a collision accident at the intersection of the vehicle 2 and
It does not depend on whether the collision prevention radar of the approaching vehicle 2 from another direction is mounted / not mounted or the difference in the radar system, so that a more flexible system configuration can be realized.

Also in this case, since the relay apparatus 1B can be entirely composed of passive circuits without using active circuits such as a transmitter and a power supply circuit, it is possible to greatly reduce the size and further reduce the power supply. Since there is no need, installation is easy. Further, the rate of occurrence of failure can be greatly reduced as compared with the case where a transmitter and a power supply circuit are provided, so that the work labor such as maintenance can be reduced.

In the third embodiment as well, the way of alerting the driver when a vehicle entering from another direction is detected (notifying method) is determined by an audible means such as an alarm sound or a visual means such as an alarm display. It may be done by any means, and automatically with or without this report,
The vehicle speed may be decelerated. (C ') Description of Modification of Third Embodiment In this modification, in a collision prevention system having the above-described relay device 1B, a pulse-type radar is applied as a vehicle-mounted radar, and a pulse wave is generated as a vehicle-mounted radar wave. Assume that it is sent from In this pulse radar, the distance to the object (vehicle 2) can be calculated from the delay time of the reflected wave with respect to the transmitted wave. For example, by measuring the time required for the pulse wave transmitted from the vehicle 2A to be reflected by the vehicle 2B via the relay device 1B and returned to the vehicle 2A via the relay device 1B again. , The distance to the vehicle 2B can be calculated.

However, in the circuit configuration described above with reference to FIG. 8, when the direction of the radar wave is changed by the relay device 1B, a delay time occurs inside the relay device 1B. This delay time appears as an error in the measured distance when viewed from the vehicle 2A. For example, when a pulse-type radar having a transmission period T is used, as shown in FIG.
"Delay time t corresponding to actual distance" + "relay device 1"
B, a delay time b ”, and the distance calculation error is the delay time b.

Therefore, in the present modification, as shown in FIG.
A delay adjuster (delay circuit) 42 for delaying the input pulse by “Tb” is provided to delay the received radar wave by “Tb” as shown in FIG. To obtain a delay time t that does not include an error. That is, after the radar wave is received by the receiving antenna 31, the delay time until the reflected wave of the radar wave is transmitted from the transmitting antenna 41 as the reflected wave transmitting unit is adjusted.

Here, since the delay time b in the relay device 1B is a value unique to the device, it may be checked in advance. If the transmission cycle T is known in advance, “Tb” is fixed, and thus “Tb” is determined using a dielectric filter having a high dielectric constant.
You only need to create a minute delay. When the transmission period T is undecided, for example, the transmission period T of the on-vehicle radar is detected by a pulse detector, and the delay of the delay time “T−b” is determined based on the detected transmission period T and the known delay time b. The circuit 42 is constituted.

Generally, the distance range to be measured is R
Then, R = C × T / 2 (4) C = 3.0 × 10 ⁸ , T = transmission pulse interval (period). If R = 200 m, from this equation (4), A transmission pulse interval is required.

T = 1.33 μs The delay time b in the relay device 1B is
Depending on the configuration of B, it is up to several hundred ns. Therefore,
Using a high dielectric constant dielectric filter or the like, T-b ≒ 1μ
A delay time of about s may be made. As described above, in the relay device 1B of this modified example, the presence and the speed of the vehicle 2 entering the intersection from another direction can be reliably detected in the same manner as in the third embodiment described above. Can accurately detect even the distance to the vehicle 2. Therefore, the same advantages as those of the third embodiment described above can be obtained, and more appropriate information can be passed to the driver, so that a collision accident at an intersection at an intersection can be more reliably prevented. .

(D) Description of Fourth Embodiment FIG. 13 is a schematic diagram for explaining the configuration of a collision prevention system according to a fourth embodiment of the present invention. The collision prevention system shown in FIG. The relay device 1 similar to that described in the embodiment (FIGS. 1 and 2) is installed at the center of the intersection of the roads A to D, and travels on each of the roads A to D like a road sign. The display devices 5A to 5D for approach notification are installed at positions (four places) near intersections that are easily visible from the vehicle 2.

Each of the display devices 5A to 5D receives the transmission radar wave (relay radar wave) from the relay device 1, and receives the vehicle 2 entering the intersection from another direction.
Is displayed on the vehicle 2 entering the intersection. For this purpose, for example, a receiver 6 is attached to the back of the display unit 51 as shown in FIG. . Focusing on the essential parts, the receiver 6 is provided with a receiving antenna 61, a mixer 62, and a local oscillator 63, for example, as shown in FIG.

Here, the receiving antenna (relay radar wave receiving section) 61 is for receiving a radar wave re-radiated from the repeater 1, and the local oscillator 63 is the same as the radar wave of the on-vehicle radar. Which oscillates in frequency,
The mixer (speed information detection unit) 62
Frequency difference information (ie, speed information) between the Doppler-shifted received radar wave from the repeater 1 and the local oscillation signal by mixing the local oscillation signal from the receiver and the radar wave received by the receiving antenna 61. It is for obtaining.

For example, as in the first embodiment, when a vehicle 2A equipped with a collision prevention radar having a transmission frequency fa enters an intersection at a speed va, a radar wave (frequency fa) from the vehicle 2A becomes In the receivers 6 of the display devices 5B to 5D,
For each radar wave (frequency
fa ′: Refer to equation (1)]. Here, the oscillation frequency of the local oscillator 63 is
When set to fa, the frequency difference information obtained by the mixer 62 is fa'-fa.

When the frequency difference information fa'-fa is processed (calculated by the Doppler equation) in a signal processing unit (not shown), the speed va of the vehicle 2A is obtained. As schematically shown in FIG. 16, the presence of the approaching vehicle 2 at the intersection and the speed information of the approaching vehicle 2 can be displayed on the display units 51 of the display devices 5B to 5D.

As a display method at this time, for example, FIG.
As shown in FIG. 6, the display unit 51 is configured as an electronic bulletin board using a light-emitting element such as a light-emitting diode, and the word “caution” is lit (flashing) in the light-emitting unit 51a. In response to the speed of the approaching vehicle 2, the light emitting units 5 of three colors, such as turning on blue and yellow at medium speed and turning on all of blue, yellow and red at high speed.
A method of displaying speed information by lighting (or blinking) 2a to 52c may be employed.

That is, the display unit 51 shown in FIG. 16 displays the presence of the vehicle 2 by, for example, emitting light of the word “caution” (light emitting unit for displaying the presence of a moving object) 5.
1a and light-emitting portions 52a to 52c whose light-emitting colors (or light-emitting states) change according to the speed information of the vehicle 2. As a result, as shown in FIG.
When the vehicle 2B enters the intersection from the direction, the vehicle 2B determines, at night, how fast the vehicle 2A enters the intersection from the information displayed on the display device 5B (electric bulletin board 51). Even under conditions of poor visibility, such as in bad weather or bad weather, it can be reliably recognized. In the same manner, the vehicle 2A or another approaching vehicle 2 from the road C or road D direction
, The vehicles 2 approach each other from other directions
Display device 5A, 5C, 5D
(Electronic bulletin board 51).

Although the operation focusing on the display devices 5A to 5D and the receiver 6 has been described here, for example,
In the vehicle 2A or the vehicle 2B, if the collision prevention radar is mounted, also in this case, as in the first embodiment, the relay device 1
By receiving the relay radar wave from, the presence and speed of each other are detected. Therefore, in the fourth embodiment, in addition to the same advantages as those of the above-described first embodiment, the display devices 5A to 5D can be installed more reliably even at night or in bad weather due to poor visibility. It is possible to prevent a collision accident at the meeting. In this case, the display devices 5A to 5D can also alert the vehicle 2 without the anti-collision radar, or a bicycle or a pedestrian to the same contents, so that the two vehicles 2 In addition to the collision accident, the effect of preventing a collision accident between the vehicle 2 and the bicycle or between the vehicle 2 and the pedestrian can be expected.

The above-mentioned receiver 6 is, for example,
As shown in (1), a filter (high-pass filter: HPF) 64 functioning as a speed information masking unit is provided, and a signal is not passed through the display unit 51 unless a certain frequency (speed) or higher. (A threshold value is provided for the frequency difference information.) Only when there is an approaching vehicle 2 at a certain speed or more, the above-described caution may be prompted. In this way, the information about the stopped vehicle 2 does not need to be transmitted to another road direction, so that the stopped vehicle 2 is not erroneously recognized as the approaching vehicle 2.

(E) Description of Fifth Embodiment FIG. 17 is a schematic diagram for explaining the configuration of a collision prevention system according to a fifth embodiment of the present invention. The collision prevention system shown in FIG. A relay device 1B similar to that described above in the embodiment (FIGS. 7 to 9) is installed at the center of the intersection of roads A to D, and in this case also, each of the roads A to The display devices 7A to 7D with the receivers 8 are provided at positions (four places) near intersections that are easily visible from the vehicle 2 traveling on D. In this case, the receiver 8 is also provided, for example, on the back surface of the display unit 71.

These display devices 7A to 7D also
Similarly to the above-described fourth embodiment, the vehicle 2 enters the intersection by receiving the relay radar wave re-emitted from the relay device 1B.
In this embodiment, the relay device 1B changes the polarization plane for each of the roads A to D as described above (see FIG. 9). Since the wave is re-emitted, take advantage of this difference in the polarization plane,
The direction of the approaching vehicle 2 can also be displayed.

For this reason, paying attention to the configuration of the main parts of the receiver 8 attached to the display devices 7A to 7D, all of them are re-emitted from the relay device 1B as shown in FIG. 18, for example. The receiving antennas 81-1 to 81-3 and the mixer 8 correspond to three systems (from three roads other than the road where the own device is installed) in accordance with the difference in the polarization plane of the radar wave.
In addition to 2-1 to 82-3, a common local oscillator 83 is provided for each polarization plane.

Here, the receiving antenna 81-1 is, for example, a relay radar wave (frequency F) of the polarization plane “1” that passes through the relay device 1B from the road on the right side toward the intersection.
1) for receiving the signal from the receiving antenna 81-
2 is a relay device 1 from the road in the front direction toward the intersection
B for receiving the relay radar wave (frequency F2) of the polarization plane “2” passing through B.
-3 is the relay device 1 from the road on the left side toward the intersection
This is for receiving the relay radar wave (frequency F3) of the polarization plane “3” passing through B.

The local oscillator 83 generates a local oscillation signal having the same frequency (for example, fa) as the transmission frequency of the on-vehicle radar, and the mixer 82-1 uses the local oscillation signal and the receiving antenna 81-1. Relay device 1B received by
By mixing a radar wave (polarization plane “1”, frequency F1) from a (vehicle 2 approaching from the right toward the intersection), the transmission frequency of the on-vehicle radar and the right from the right toward the intersection are mixed. Frequency difference information (F1-f) with the Doppler-shifted radar wave from the incoming vehicle 2
a).

Similarly, mixer 82-2 transmits a radar wave (polarization plane) from relay apparatus 1B (vehicle 2 approaching the intersection from the front) received by local oscillation signal and reception antenna 81-2. The frequency difference information (F2) between the transmission frequency of the on-vehicle radar and the radar wave subjected to the Doppler shift from the vehicle 2 entering from the front toward the intersection by mixing the “2” and the frequency F2). -f
a), and the mixer 82-3 includes the local oscillation signal and the relay device 1B received by the reception antenna 81-3.
By mixing the radar wave (polarization plane “3”, frequency F3) from the (vehicle 2 entering from the left toward the intersection), the transmission frequency of the vehicle-mounted radar and the leftward toward the intersection are mixed. Frequency difference information (F3-f) from the radar wave that has undergone the Doppler shift from the vehicle 2 entering
a).

The mixers 82-1 to 82-
Each of the frequency difference information obtained by the
The signals are input to signal processing units (not shown) provided for each of 2-1 to 82-3, and these signal processing units use the Doppler effect formula based on each frequency difference information to calculate the vehicle to the intersection. A second approach speed is required. Thereby, the receiver 8
In, the existence and speed of the approaching vehicle 2 to the intersection are determined for each road direction except for the road on which the own device is installed. As a result, the existence and speed of the approaching vehicle 2 to the intersection from another direction are determined. In addition, the direction of approach is also indicated by the display device 7.
A to 7D can be displayed.

That is, the above-described receiving antennas 81-1 to 81-1-8
1-3, the mixers 82-1 to 82-3 and the oscillator 83 function as a polarization plane identification unit for identifying the polarization plane of the radar wave received from the relay apparatus 1B, and move the vehicle 2 according to the identification result. Information about the direction is displayed on the display unit 71. For example, consider the case where the vehicle 2A and the vehicle 2B respectively enter the intersection as shown in FIG. In this case, the radar wave (frequency fa) transmitted from the on-vehicle radar of the vehicle 2A receives the Doppler shift as described above in the third embodiment, and receives the frequency f.
The signal is received by the relay apparatus 1B as the radar wave a ', and is re-emitted in the directions of the roads B to D other than the road A, respectively.
At this time, for example, it is re-emitted with the polarization “1” in the direction of the road B, with the polarization “2” in the direction of the road C, and with the polarization “3” in the direction of the road D.

On the other hand, the radar wave (frequency fb) transmitted from the on-vehicle radar of the vehicle 2B is similarly subjected to Doppler shift, received as a radar wave of frequency fb 'by the repeater 1B, It is re-emitted with polarization "1" in direction A, with polarization "2" in direction D, and with polarization "3" in direction C. Thus, for example, when attention is paid to the display device 7D installed on the road D, the receiver 8 has a radar wave (frequency fa ') of the polarization "1" from the relay device 1B as shown in FIG. And the radar wave of polarization “2” (frequency fb ′) are received by the receiving antenna 81−
1, 81-2, and the mixer 8
In 2-1 and 82-2, the frequency difference information fa'-fa, f
b′−fb is obtained.

Then, each of these frequency difference information fa'-f
a, fb′−fb are respectively input to a signal processing unit that performs processing when “vehicles approaching from the right” exists and a signal processing unit that performs processing when “vehicles approaching from the front” exists. Thereby, the vehicle 2A,
2B speeds are determined respectively. In the display device 7D,
The speed of the approaching vehicle 2 obtained by the receiver 8 in this manner,
By displaying information about the approach direction on the display unit 71,
The driver of the vehicle 2 (the radar may be not mounted) traveling on the road D toward the intersection can be alerted. Of course, when the vehicle 2 exists on the road C or the road D,
An operation similar to the above is obtained.

Here, as a display method at this time, for example, as shown in FIG. 20, by providing a cross area 72 representing an intersection on the display section 71, the presence of the intersection is displayed, and the cross area 72 is displayed. Is provided with a light-emitting unit 73 representing the vehicle 2 to indicate the presence of the vehicle 2 that is approaching by lighting (or blinking), and displaying the emission color of the receiver 8.
The vehicle speed may be displayed by changing the speed in accordance with the speed obtained in the above (for example, red at a predetermined speed (for example, 50 km / h) or higher, and yellow at a speed lower than that).

That is, the display unit 71 shown in FIG.
For example, it is configured as an electric bulletin board using a light emitting element such as a light emitting diode, and a point (intersection) where the vehicle 2 can enter.
(Cross area; point display area) 72 for displaying information (shape in the above case) about
2, the presence of the vehicle 2 and the above-mentioned polarization plane identification units (receiving antennas 81-1 to 81-3, mixers 82-1 to 82-
The direction of movement of the vehicle 2 (the direction of approach to the intersection) according to the polarization plane identified in 3) is displayed by light emission, and the direction in which the light emission color (or light emission state) changes according to the speed of the vehicle 2. It has a light emitting section 73 for speed display.

In this manner, the driver can be reliably alerted even at night or when visibility is poor due to bad weather. If the cross region 72 is also configured as a light emitting unit, the existence of the intersection itself can be highlighted. However, in this case, in order to further emphasize the presence of the vehicle 2 (the light-emitting unit 73), the cross-shaped region 72 suppresses the light-emitting intensity thereof from the light-emitting intensity of the light-emitting unit 73 or reduces the light-emitting color from the light-emitting color of the light-emitting unit 73. It is better to make the color less noticeable.

Although the description has been given of the operation focusing on the relay device 1B, the display devices 7A to 7D, and the receiver 8, the fifth embodiment is similar to the third embodiment described above. In the vehicle 2 equipped with the prevention radar, the vehicle 2 does not rely on the radar wave of the approaching vehicle 2 from another direction.
The presence and speed of the approaching vehicle 2 can be detected using only the radar waves of the on-vehicle radar.

As described above, according to the fifth embodiment,
By installing the same relay device 1B as described above in the third embodiment at the center of the intersection, and installing the display devices 7A to 7D with the receiver 8 on each of the roads A to D forming the intersection, In addition to obtaining the same operation and effect as the third embodiment, not only the presence or absence and speed information of the vehicle 2 entering the intersection, but also the direction of approach can be displayed to the driver to call attention. In addition, it is possible to more effectively prevent a collision accident at an intersection.

In this embodiment, also, the on-vehicle radar is a pulse type radar, and the above-described relay apparatus 1B is connected to the radar shown in FIG.
(A configuration in which the delay adjuster 42 is provided). In this case, as described above, the vehicle 2 approaching the intersection not only has the presence / absence and speed of the vehicle 2 approaching from the other, but also The distance to the vehicle 2 can also be accurately measured.

Further, in the above-described display devices 7A to 7D (or 5A to 5D), when the relay radar wave from the relay device 1B (1) cannot be received (or
After a lapse of a predetermined time from the reception failure, the above-described light emission display may be stopped (stopped). Further, the display devices 7A to 7D (or 5A to 5D) (hereinafter, symbols are omitted) are not limited to the case where the relay radar wave cannot be received, and the display devices 7A to 7D (hereinafter, reference numerals are omitted) according to the reception state of the relay radar wave (for example, the reception level If the level falls below a certain level or C
/ N is degraded), the above-described light emitting display may be stopped.

Further, the display time may be changed according to the detected vehicle speed. For example, a timer is provided in the display device, and when the vehicle speed detected by receiving the relay radar wave is fast, a shorter time is set in the timer, and when the detected vehicle speed is slow, a longer time is set in the timer. A time is set so that when the detected vehicle speed is low, the above-described light emission display is performed longer than when the detected vehicle speed is high. At this time, the set time for the timer was divided by the speed at which the display device detected the distance from the farthest place (from the display device) where the relay radar wave could be received (from the display device) to the inside of the intersection (the entrance or center of the intersection). It is desirable to make it about the value.

(F) Others In each of the above embodiments and modifications, the relay devices 1 and 1
In both cases, A and 1B re-radiate the radar wave of the on-vehicle radar in the opposite (front) direction (for example, in the case of the radar wave received from the direction of the road A, the direction of the road C). In the case where the vehicle 2 is orthogonal or substantially orthogonal as shown in FIGS. 5, 7, 13, and 17, the presence of the vehicle 2 entering the vehicle from the opposite direction is often visible to the driver. Circuit may be omitted or the function may be stopped so that the radar wave is not re-emitted in the opposite direction.

However, for example, when the shape of the intersection is as shown in FIG. 21 and the visibility is poor, for example, the reception radar wave is set at an angle corresponding to the direction of the road on the opposite road side. It is better to re-emit.
By doing so, the straightness of the radar wave on the vehicle
Only the in-vehicle radar for collision prevention can detect a part that could not be detected.

In each of the above-described embodiments and modifications, the case where the relay devices 1, 1A, 1B are installed at four-point intersections has been described. It may be installed at a turning corner such as a junction, at an intersection where five or more roads intersect, or at a place with poor visibility through which a moving object such as the vehicle 2 can pass. In this case, the same operation and effect as described above can be obtained. can get.

Further, although the description has been omitted in the above-described example, a display device with a receiver is applied to the collision prevention system described in the second embodiment, as in the fourth and fifth embodiments. You may. Further, in the above-described example, a CW radar or a pulse type radar is applied as the on-vehicle radar. However, the present invention is not limited to this, and a radar in which the above-described frequency difference information is obtained and the speed information of the vehicle 2 is obtained. if there is,
Any type of radar may be applied.

Further, the radar need not necessarily be mounted on an automobile, but may be mounted on a motorcycle, for example. In this case, it is possible to reliably prevent not only the vehicle 2 but also a collision accident at the intersection between the vehicle 2 and the motorcycle or between the motorcycles. Also, in the above example,
Although the polarization plane is changed by changing the polarization of the re-emitted radar wave to linear polarization and changing its angle, for example, as described above, if only the left and right directions are to be re-emitted, except the front direction Alternatively, the plane of polarization may be changed by changing the rotation direction of the circularly polarized wave.

The present invention is not limited to the above-described embodiments and modifications, and can be implemented with various modifications without departing from the spirit of the present invention.

[0104]

As described above in detail, according to the approaching radar wave relay device of the present invention (claim 1), a radar wave from a moving object is received and the transmission direction of the received radar wave is changed. Since the direction can be changed to a direction different from the direction in which the radar wave is transmitted, the following advantages are obtained.

For example, by merely installing the relay device at an intersection with poor visibility, the existing radar can be used as it is, and the presence (approach) of the moving object from another direction can be reported to the moving object. It is possible to reliably prevent a collision accident at a meeting of a moving object. A moving object equipped with radar can detect not only the presence or absence of another moving object approaching from another direction, but also the speed of that moving object. Nothing to do.

Since the radar wave is used, it is not affected by the weather or the like. Since it is only necessary to change the transmission direction of the received radar wave, it is possible to configure all passive circuits without using active circuits such as transmitters and power supply circuits, and it is possible to greatly reduce the size and cost. is there. Since there is no need for power supply, installation is easy, and the rate of occurrence of failures can be greatly reduced as compared with the case where a transmitter and a power supply circuit are provided, so that work such as maintenance can be reduced. .

Here, the radar wave relay apparatus may receive the reflected wave of the radar wave transmitted by changing the transmission direction as described above, and transmit the reflected wave toward the moving object. In this case, the moving object uses only the radar wave of its own radar (regardless of whether the other moving object is a radar transmission frequency and whether or not the radar is mounted), and the presence of the other moving object ， Because speed can be detected,
A collision prevention system can be flexibly constructed (claim 2).

The radar wave relay apparatus may include a polarization plane conversion unit for converting the plane of polarization of the received radar wave into a plane different from the original plane.
It is possible to detect the presence and speed of a moving object from another direction while preventing interference with a radar wave that arrives directly from an opposing moving object (claim 3). Furthermore, after the radar wave from the moving object is received by the radar wave relay device,
A delay adjuster for adjusting a delay time until the reflected wave of the radar wave is transmitted to the same moving object may be provided. With this configuration, the moving object can accurately detect the distance to another moving object (claim 4).

Further, according to the radar wave relay device of the present invention (claim 5), a radar wave from a moving object is transmitted back toward the moving object, and the reflected wave and the above-mentioned folded radar wave are transmitted from the reflected wave. The speed information of the moving object is detected, and the speed information is added to the radar wave received from another direction different from the direction in which the radar wave has been transmitted and transmitted in the other direction. Even when the transmission frequency of its own radar wave is different from the transmission frequency of the radar wave of another moving object, it is possible to detect the accurate speed of another moving object. Therefore, it is possible to reliably recognize the approach of the moving object from another direction and avoid a collision accident. Also in this case, since the radar wave relay device can be configured by a passive circuit, the failure rate can be significantly reduced and the cost can be reduced.

Further, the display device for approach notification according to the present invention relays a radar wave received from a moving object by a radar wave relay device capable of changing the direction of the radar wave to a direction different from the direction in which the radar wave was transmitted. Receives the relayed radar wave, detects the speed information of the moving object from the relayed radar wave, and displays the speed information. Can be notified of approach and speed. Further, not only a moving object but also a nearby pedestrian or the like can be notified in a similar manner to call attention (claim 6).

Here, the speed information may be displayed only when the detected speed information is equal to or higher than a predetermined threshold value. In this case, the display of the stopped moving object is performed. Can be excluded, and it is not erroneously recognized that a stopped moving object is approaching (claim 7). Also, by identifying the polarization plane of the radar wave received from the radar wave relay device and displaying information on the moving direction of the moving object according to the polarization plane, not only the approach and speed of the moving object, but also , It is possible to notify even the approach direction, so that the occurrence of a collision accident can be prevented more reliably.

Here, in the display device of the present invention, the presence of a moving object can be displayed by light emission, and the light emission color or light emission state can be changed according to the speed. Even under conditions of poor visibility such as weather and bad weather, the presence and speed of a moving object can be reliably reported, so that a collision accident of the moving object can be effectively prevented (claim 9). ).

Further, the display device of the present invention displays information on a point at which a moving object can enter, and displays the presence and speed of the moving object approaching the point by emitting light.
It is also possible to change the emission color or emission state according to the speed of the moving object, and in this way, from which direction the moving object approaches the above point at what speed Can be reliably notified even under poor visibility such as at night or in bad weather, so that a collision accident of a moving object can be effectively prevented (claim 10).

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a collision prevention system to which a radar wave relay device for approach notification according to a first embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a detailed configuration of the relay device shown in FIG.

3 (A) and 3 (B) are diagrams each showing an example of a twisted waveguide applied as a polarization plane converter of the repeater shown in FIG. 2;

FIGS. 4A and 4B are schematic diagrams for explaining a polarization plane of the relay apparatus shown in FIG. 2;

FIG. 5 is a schematic diagram for explaining a collision prevention system to which an approach notification radar wave relay device according to a second embodiment of the present invention is applied.

FIG. 6 is a block diagram illustrating a detailed configuration of the relay device illustrated in FIG. 5;

FIG. 7 is a schematic diagram illustrating a collision prevention system to which a radar relay device for approach notification according to a third embodiment of the present invention is applied.

8 is a block diagram showing a detailed configuration of the relay device shown in FIG.

9 is a schematic diagram for explaining a polarization plane (when viewed from the direction of road A) of the relay device shown in FIG. 7;

FIG. 10 is a block diagram illustrating another detailed configuration of the relay device illustrated in FIG. 7;

11 is a diagram for explaining a delay adjusting operation in the relay device shown in FIG. 10;

FIG. 12 is a diagram for explaining a delay adjustment operation in the relay device shown in FIG. 10;

FIG. 13 is a schematic diagram illustrating a configuration of a collision prevention system according to a fourth embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a receiver attached to the display device shown in FIG.

FIG. 15 is a block diagram showing another configuration of the receiver attached to the display device shown in FIG.

FIG. 16 is a schematic view showing the appearance of the display device shown in FIG.

FIG. 17 is a schematic diagram illustrating a configuration of a collision prevention system according to a fifth embodiment of the present invention.

18 is a block diagram illustrating a configuration of a receiver attached to the display device illustrated in FIG.

19 is a block diagram showing a configuration of a receiver attached to the display device shown in FIG.

20 is a schematic diagram illustrating an appearance of the display device illustrated in FIG.

FIG. 21 is a schematic diagram illustrating an example of an intersection with poor visibility.

[Explanation of symbols]

1, 1A, 1B radar wave relay device 2, 2A, 2B Vehicle (moving object) 3A to 3D, 10A to 10D Road A to D direction circuit 5A to 5D, 7A to 7D Display device 6, 8 Receiver 11A to 11D , 21A, 21B, 31 Receiving antenna (radar wave receiving unit) 12A to 12D, 27A, 27B Distributor 13A to 13D, 28A, 28B, 40 Combiner 14A to 14D Circulator 15A to 15D Polarization plane converter (twisted waveguide) ) 16A to 16D, 34, 36, 38, 41 Transmitting antennas 22A, 22B, 33 Dividers 23A, 23B Transmitting antennas (return transmitters) 24A, 24B Directional couplers 25A, 25B, 35, 37, 39 Receiving antennas ( Reflected wave receiving unit) 26A, 26B mixer (speed information detecting unit) 29A, 29B mixer (speed information added transmission) 30A, 30B Transmitting antenna (speed information adding transmitting unit) 32 Amplifier 42 Delay adjuster 51, 71 Display unit 51a Light emitting unit (light emitting unit for displaying moving object presence) 52a to 52c Light emitting unit (light emitting unit for displaying speed information) 61, 81-1 to 81-3 Receiving antenna (relay radar wave receiving unit) 62, 82-1 to 82-3 Mixer (speed information detecting unit) 63, 83 Local oscillator 64 Filter (HPF; speed information masking unit) 72 Cross-shaped area (point display area) 73 Light-emitting section (light-emitting section for direction / speed display) AD Road

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H180 AA01 CC14 CC15 HH14 JJ06 JJ22 LL02 LL04 LL07 LL08 LL15 5J070 AB01 AB15 AC02 AC06 AD02 AD17 AE01 AF03 AH39 AK22 BA01 BD08 BF02 BF03

Claims (10)

[Claims] 1. A radar wave receiving unit for receiving a radar wave from a moving object, and changing a radar wave received by the radar wave receiving unit to a direction different from a direction in which the radar wave is transmitted. A radar wave relay device for approach notification, comprising a receiving radar wave transmission direction changing unit capable of transmitting. 2. A radar wave receiving unit for receiving a radar wave from a moving object, and changing a radar wave received by the radar wave receiving unit to a direction different from a direction in which the radar wave is transmitted. A receiving radar wave transmitting direction changing unit capable of transmitting, a reflected wave receiving unit receiving a reflected wave of a radar wave transmitted from the receiving radar wave transmitting direction changing unit, and the reflected wave received by the reflected wave receiving unit And a reflected wave transmitting unit for transmitting the reflected wave toward the moving object. 3. The reception radar wave transmission direction changing unit includes a polarization plane conversion unit that converts a polarization plane of a radar wave received by the radar wave reception unit into a different polarization plane. 2. A radar wave relay device for approach notification according to claim 1. 4. A delay adjuster for adjusting a delay time from when the radar wave is received by the radar wave receiver to when a reflected wave of the radar wave is transmitted from the reflected wave transmitter. 3. The radar wave relay device for approach notification according to claim 2, wherein: 5. A radar wave receiving unit for receiving a radar wave from a moving object, a return transmitting unit for returning the radar wave received by the radar wave receiving unit to the moving object, and the return transmitting unit. A reflected wave receiving unit that receives a reflected wave of the folded radar wave transmitted from the moving object, a velocity information detecting unit that detects velocity information of the moving object from the folded radar wave and the reflected wave, A speed information addition transmitting unit that adds the speed information detected by the speed information detecting unit to a radar wave received from another direction different from the direction in which the radar wave is transmitted and transmits the radar wave to the other direction. A radar wave relay device for approach notification, comprising: 6. A relay radar for receiving a relay radar wave relayed by a radar wave relay apparatus capable of changing a radar wave received from a moving object to a direction different from the direction in which the radar wave was transmitted and transmitting the radar wave. A wave information receiving unit, a speed information detecting unit for detecting speed information of the moving object from the relay radar wave received by the relay radar wave receiving unit, and a speed information detected by the speed information detecting unit. A display device for approach notification, comprising a display unit. 7. A speed information mask unit for supplying the speed information to the display unit only when the speed information detected by the speed information detection unit is equal to or more than a predetermined threshold value. The display device for preventing collision of a moving object according to claim 6. 8. The relay radar wave receiving section includes a polarization plane identification section for identifying a polarization plane of a radar wave received from the radar wave relay apparatus, and the display section identifies the polarization plane by the polarization plane identification section. 7. The display device for approach notification according to claim 6, wherein information on a moving direction of the moving object is displayed according to the determined polarization plane. 9. A light emitting unit for displaying the presence of a moving object, which emits light to indicate the presence of a moving object, and a light emitting unit for displaying speed information, whose emission color or light emission state changes according to the speed information of the moving object. A display device for approach notification. 10. A point display area for displaying information about a point at which a moving object can enter, and in the point display area, the presence and the moving direction of the moving object are illuminated and displayed. A display device for approach notification, comprising: a light emitting unit for displaying a direction and a speed at which a light emitting color or a light emitting state changes according to a moving speed.