JPH10166974A - Rear side alarm system for vehicles - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a rear side warning device for a vehicle which can perform a warning to prevent a contact with a following vehicle when a vehicle changes lanes, thereby improving the reliability of warning. To do. SOLUTION: In a rear side warning device for a vehicle that detects a following vehicle running on the rear side of a host vehicle 10 and warns a driver, when a following vehicle approaches the host vehicle 10, An alarm determining unit 151 for determining whether or not to issue an alarm to the driver; and a collision of the following vehicle with the own vehicle 10 by braking the following vehicle when the own vehicle 10 changes lanes in front of the following vehicle. The collision avoidance determining means 152 and the warning determining means 151 determine whether or not the warning is possible, and the collision avoiding determining means 152 determines that it is impossible to avoid the collision by braking the following vehicle. Alarm means 8 for giving an alarm to the driver when the warning is given.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a following vehicle traveling behind a host vehicle and determines whether it is possible to safely change lanes or make a right or left turn. The present invention relates to a rear alarm device for issuing a warning to a vehicle.

[0002]

2. Description of the Related Art When a vehicle travels, safety is ensured by maintaining a predetermined distance between the vehicle and a following vehicle traveling around the vehicle. When changing the course, by changing the travel route,
It is necessary to ensure a sufficient relative distance to the following vehicle.

As shown in FIG. 10, during normal driving, a driver can check a direct view area A1 without moving his / her eyes.
And the rearview mirror can secure the view of the rearview mirror area A2 by the rearview mirror and the rear left and right side mirrors A3 and A4 by the left and right side mirrors by slightly moving the line of sight.
The view is secured.

[0004] By the way, the driver directly moves the view area A1 and the rearview mirror area A2 without moving his / her eyes.
Although the visibility of both areas can be relatively easily secured because of the visibility of the left side area A3 and the rear right area A4, which slightly move the eyes, it is easy to neglect. For this reason, it is difficult for the driver to always easily maintain the field of view of the vehicle at all 360 degrees, and it has been particularly desired to easily secure the rear side field of view when changing lanes or turning left or right.

Therefore, various devices for detecting the objects in the rear side area of the host vehicle by means of an object detecting means such as a radar instead of the driver to assist the driver in ensuring the visibility and improving the running safety of the vehicle. Have been proposed in JP-A-5-139227 and JP-A-4-58179. JP 5
Japanese Patent Application Publication No. 139227 discloses a device that issues a warning if the absolute value of the relative speed between the host vehicle and the following vehicle is within a predetermined value. Japanese Unexamined Patent Publication No. 4-58179 discloses that a radio wave radar is provided on each of the right and left side walls of a host vehicle and right and left sides of a rear bumper, and the radio wave radar is operated when a turn lever is operated. On the other hand, there is described a device which issues an alarm when an obstacle such as a following vehicle is detected. Further, when the turn lever is operated, the detection range of the radio wave radar is adjusted according to the vehicle speed.

However, the above-mentioned Japanese Patent Application Laid-Open No. Hei 5-1392 discloses
No. 27 and Japanese Patent Application Laid-Open No. 4-58179 detect whether or not there is a following vehicle in a detection area behind the host vehicle, and issue an alarm when a following vehicle is detected. It is not sufficiently determined whether or not the current running state of the host vehicle has a high risk of causing contact with a following vehicle, and there is a problem that a useless alarm may be issued. .

Therefore, when the own vehicle attempts to change course, the collision position between the own vehicle and the following vehicle is predicted and calculated, the arrival times of the own vehicle and the following vehicle to the predicted positions are compared, and the arrival time of the own vehicle is calculated. Japanese Patent Application Laid-Open Publication No. HEI 9-26139 discloses an apparatus that outputs a safety signal when the vehicle arrival time is shorter than the arrival time of the following vehicle, and outputs a danger signal when the arrival time of the own vehicle is longer than the arrival time of the following vehicle. It is described in JP-A-3-255975.

[0008]

However, when the own vehicle attempts to change lanes in front of the following vehicle and the following vehicle brakes, the inter-vehicle distance between the own vehicle and the following vehicle becomes longer. Since the possibility of a collision is eliminated, the host vehicle can often safely change lanes. Japanese Patent Laid-Open No. Hei 3
In the device described in JP-A-255975, safety is determined by predicting and calculating the collision position between the host vehicle and the following vehicle. However, the case where the running state of the following vehicle changes is not considered. Therefore, when the following vehicle performs braking or when the following vehicle can avoid collision with the own vehicle, the lane of the own vehicle can be changed, and there is a problem that a useless alarm is issued.

Therefore, the present invention provides a rear-side alarm device for a vehicle which can perform an alarm for preventing a contact with a following vehicle when the lane of the own vehicle changes, thereby improving the alarm reliability. Is to do.

[0010]

According to a first aspect of the present invention, there is provided a rear side warning device for a vehicle which detects a following vehicle running on the rear side of the host vehicle and issues an alarm to a driver. A following vehicle detecting means for detecting a vehicle, a relative distance calculating means for calculating a relative distance between the own vehicle and the following vehicle from an output of the following vehicle detecting means, and a relative distance between the own vehicle and the following vehicle from an output of the following vehicle detecting means. Relative speed calculating means for calculating the speed,
When the following vehicle approaches the own vehicle, an alarm determining unit that determines whether or not to warn the driver based on each output of the relative distance calculating unit and the relative speed calculating unit; When the lane is changed forward, it is determined whether or not it is possible to avoid the collision of the following vehicle with the own vehicle by braking the following vehicle based on the outputs of the relative distance calculation means and the relative speed calculation means. When the collision avoidance determining means and the warning determining means determine that a warning is to be given and the collision avoidance determining means determines that collision avoidance by braking of a following vehicle is impossible, the driver is warned. And alarm means for performing the following.

A second aspect of the present invention is a rear side warning device for a vehicle which detects a following vehicle traveling on the rear side of the host vehicle and issues a warning to a driver. Detecting means, relative distance calculating means for calculating the relative distance between the vehicle and the following vehicle from the output of the following vehicle detecting means,
A relative speed calculating means for calculating a relative speed between the own vehicle and the following vehicle from an output of the following vehicle detecting means; and a relative distance calculating means and a relative speed calculating means when the following vehicle approaches the own vehicle. Based on the respective outputs of the relative distance calculating means and the relative speed calculating means when the own vehicle attempts to change lanes ahead of the following vehicle. Before the own vehicle changes lanes, it is determined by the passage determining means that determines whether or not the following vehicle can pass the side of the own vehicle, and the warning determining means determines that an alarm is to be issued, and the passing determining means And a warning unit that warns the driver when it is determined that the following vehicle cannot pass.

According to a third aspect of the present invention, in the vehicle rear side alarm device according to the first or second aspect, when it is detected that the vehicle speed of the own vehicle is lower than a predetermined value and that the turn lever is operated. A right or left turn detecting means for detecting a right or left turn of the own vehicle. When the right or left turn of the own vehicle is detected by the right or left turn detecting means, the following vehicle detecting means detects the right or left turn of the own vehicle. The detection area of the following vehicle in the folding direction is narrowed.

[0013]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a rear side alarm device of the present invention.
In the figure, reference numeral 9 indicates a rear side alarm device. The rear side alarm device 9 includes a scanning laser radar 12 as a following vehicle detecting means for detecting a following vehicle traveling behind the host vehicle, and various controls based on signals from the laser radar 12. The controller 15 performs a warning, a warning unit 8 that warns a driver when the own vehicle is likely to come into contact with something other than the own vehicle when the course is changed or when turning right or left, and a detection result by the laser radar 12 is output. It mainly comprises a display device 14 for constantly displaying.

As shown in FIG. 2, a laser radar 12 is disposed substantially at the center of the rear bumper 11 at the rear end of the vehicle 10. A display device 14 is provided on a center console inside the vehicle 10 so as to be seen by a driver.

As shown in FIGS. 2 and 3, in the delta zone 181 inside the left and right door mirrors 18, 18, an amber color light 20 and a red light 21 as alarm means 8 are provided, respectively. FIG. 3 shows a part of the left side door mirror 18. The alarm means 8 is configured by adding a buzzer 22 to an amber color light 20 and a red light 21, and the buzzer 22 is disposed at a predetermined position in a vehicle interior. The operations of the amber light 20, the red light 21 and the buzzer 22 are controlled by the controller 15 via the corresponding drive circuits 23, 24 and 25 (see FIG. 1).

In FIG. 1, a laser radar 12 includes a casing 121 integrally attached to an upper wall member 111 of a rear bumper 11, a light transmitting / receiving circuit section 122 supported on a lower wall in the casing 121, and a light transmitting / receiving circuit 122. Circuit section 122
A light transmitting and receiving unit 123 connected to and disposed above the
It faces upward and downward with respect to the light transmitting / receiving section 123, and
The mirror 124 rotates while maintaining the state of the inclination angle of 5 °.
Supported by the casing 121 and the mirror 1
24 mainly includes a mirror driving unit 125 that supports the rotation of the mirror 24 around the vertical line C1. In the present embodiment, the laser radar 12 is mounted on the upper part of the rear bumper 11, but may be mounted so as to protrude from the rear end of the rear bumper 11 as long as the position does not limit the scanning range of the laser radar 12. .

The light transmitting / receiving section 123 is driven by the light transmitting / receiving circuit section 122 to emit laser light at predetermined intervals, and receives reflected light reflected by the emitted laser light colliding with a following vehicle. At this time, the transmission / reception direction is mirror 124
Thus, the horizontal direction of the light transmission / reception (rotation angle θ) changes sequentially according to the rotation position of the mirror 124. The mirror 124 of the casing 121
A transparent plate d that transmits a laser beam is disposed at a portion opposed to.

Here, the rotation speed of the mirror 124 and the light transmission / reception cycle of the light transmission / reception circuit unit 122 will be described. The rotation speed of the mirror 124 and the light transmission / reception cycle of the light transmission / reception circuit unit 122 are set as appropriate. For example, the rotation speed of the mirror 124 is set for each control cycle Δt of the light transmission / reception circuit unit 122.
The rotation angle θ, which is the light transmission / reception angle, is set to change by the unit rotation angle, and the light transmission / reception cycle of the light transmission / reception circuit unit 122 is one rotation behind the vehicle 10 during one rotation of the mirror 124.
In the scan area e0 of 80 ° (see FIG. 7), the information is set so that information on the relative distance L to the succeeding vehicle can be acquired for each unit rotation angle. The laser radar 12 used in this apparatus has a scan area e0, which is a detectable area.
(See FIG. 7) that can reliably detect the detection regions E1 and E2 is used. Further, the following vehicle detection means described above is wide in the horizontal direction in the rear view of the vehicle 10,
For example, as long as the information of the relative distance L to the succeeding vehicle is sequentially detected at every predetermined rotation angle θ from the scan area e0 or the like, not only the scanning laser radar 12 but also other detection means may be used. good.

The laser radar 12 is connected to a radar driving circuit 13 for controlling the driving of the laser radar 12. As shown in FIG. 4, the radar drive circuit 13 calculates a relative distance between the vehicle 10 and the following vehicle based on an output from the laser radar 12, and calculates a relative distance between the vehicle 10 and the following vehicle. And a relative speed calculating means 132 for calculating a speed.

The radar driving circuit 13, as shown in FIG. 5, the reference of the detection result of the following vehicle p _1, p _2, · · · ·, the vehicle width direction based on the data of the p _n (X-axis direction) Line x,
A reference line y in the vehicle traveling direction (Y-axis direction) is calculated, and a point p ₀ (X ₀ , Y ₀ ) located at the intersection of the two lines is determined as a reference point of the following vehicle.

The relative distance calculating means 131 calculates a rotation angle θ _n (= θ _n-1 + Δ) based on the reference point (X ₀ , Y ₀ ).
θ), the relative distance L ｛= {(X _n ² + Y _n ² )} between the vehicle 10 and the following vehicle at that time is detected for each unit rotation angle, and the position of the following vehicle (X _n, it calculates the Y _n). Then, these data are output from the output terminal to the display device 14 and the controller 15.

The relative speed calculation means 132 calculates the reference point p
₀ (X ₀ , Y ₀ ) and the previous reference point p _0-1 (X _0-1 , Y _0-1 )
And the control cycle Δt, and the relative speed Δvx ｛of the following vehicle with respect to the vehicle 10 in the X-axis direction = (X ₀₋₁ −X ₀ ) / Δt｝,
Relative velocity in the Y-axis direction Δvy ｛= (Y _0-1 −Y ₀ ) / Δt｝
Are calculated respectively.

In this embodiment, the relative distance in the vehicle traveling direction Y, that is, the distance from the rear end of the vehicle 10 to the reference point (Y ₀ ) in the Y-axis direction is described as the inter-vehicle distance D, and the description is simplified. The description of the relative distance in the vehicle width direction X is omitted for the sake of convenience. Similarly, the relative speed Δvy in the vehicle traveling direction Y is hereinafter simply referred to as the relative speed Δv, and the description of the relative speed Δvx in the vehicle width direction X is omitted for simplification of the description.

The display device 14 is a display circuit unit 1 to which outputs from the radar drive circuit 13 and the controller 15 are input.
41, and a display unit 142 driven by the circuit unit. As the display unit 142, for example, a liquid crystal display is used. In addition, a CRT or a HUD may be used. The display circuit unit 141 displays the display state shown in FIG. 5, that is, the rear end of the vehicle 10 and the detection state of the rear side of the vehicle 10 on the display unit 142. In the figure, a detection area E1 is a detection area when the vehicle is traveling straight ahead, and a detection area E3.
Represents the detection area when turning left. The display circuit unit 141 sequentially displays the positions of the following vehicles at the respective rotation angles θ _n at the corresponding positions on the display screen by using □ points. Further, the speed V2 of the following vehicle is numerically displayed at substantially the center of the display unit 142 (in FIG. 5, 120 km / h is displayed).

The controller 15 includes a laser driving circuit 1
3, display circuit 141, alarm means 8, vehicle speed sensor 16, and turn signal switch 17 are connected to each other. The vehicle speed sensor 16 detects the speed of the vehicle 10 and outputs the vehicle speed V1 to the controller 15. The turn signal switch 17 turns the turn signal signal W when turning right.
_R and the turn signal signals W _L respectively detected during left turn, the controller 15 in the turn signal signals W _R, and outputs the W _L.

The main part of the controller 15 is constituted by a microcomputer, and it is determined whether or not to give a warning to the driver from each output (inter-vehicle distance D, relative speed Δv) of the relative distance calculating means 131 and the relative speed calculating means 132. And whether the collision of the following vehicle with the vehicle 10 can be avoided by braking the following vehicle when the vehicle 10 changes lanes in front of the following vehicle. Collision avoidance determination means 152 and passage determination means for determining whether or not the following vehicle can pass the side of the vehicle 10 before the vehicle 10 changes lanes when the following vehicle enters the detection areas E1 and E2. 153 and right / left turn detecting means 154 for detecting right / left turn of the vehicle 10.

The controller 15 controls the driving circuits 23 and 2 of the alarm means 8 based on input signals of the vehicle speed V1, the turn signal signals W _R and W _L , the inter-vehicle distance D and the relative speed Δv.
A driving signal is output to each of the motors 4 and 25, a warning is issued to the driver, and a detection area change signal is output to the laser drive circuit 13 to change the detection area of the following vehicle.

Hereinafter, each of the means 151 to 154 will be described in detail. As shown in FIG. 7, the detection areas E1,
E2 is a main detection area for detecting a following vehicle when changing lanes, and is set in advance on the left and right sides of the vehicle 10, respectively. Detection regions E1, E2 are set, the distance Ly ₁ toward the rear from the rear end of the vehicle 10 in the vehicle traveling direction Y, by a rectangular region formed by the distance Lx ₁ toward the outside from the vehicle body side wall in the vehicle width direction Have been. The distance Ly ₁ is a distance at which it becomes difficult for the driver to confirm the vehicle approaching from the rear side by the rearview mirror, and the distance Lx ₁ is:
The distance includes at least the lane adjacent to the vehicle body side wall. In the present embodiment, the distance Ly ₁ is set to 10 m, and the distance Lx ₁ is set to 5 m.

The inter-vehicle distance D, the relative speed Δv, and the vehicle speed V1 are input to the alarm determining means 151. The alarm determination means 151 calculates the speed V2 of the following vehicle by adding the vehicle speed V1 of the vehicle 10 to the relative speed Δv, and determines whether the following vehicle is in the detection area E based on the following distance D and the relative speed Δv.
It is determined whether the vehicle has entered 1, E2. Then, it outputs to the display device 14 the speed V2 of the following vehicle and information on the following vehicle that has entered the detection areas E1 and E2.

The right / left turn detecting means 154 is provided with the vehicle speed sensor 16.
A right or left turn of the vehicle 10 is detected based on the output from the turn signal switch 17. That is,
The left / right turn detecting means 154 detects the vehicle speed V1 from the vehicle speed sensor 16.
Is the speed V at which it is determined that a right or left turn is made at an intersection or the like
a following, for example, not more than 20 km / h, and, when the turn signal signals W _R or turn signal signal W _L is input from the turn signal switch 17, the vehicle 1
It is determined that 0 performs a right turn or a left turn. Note that the turn signal signals W _R and W _L from the turn signal switch 17 are provided.
Alternatively, the determination may be made based on the operation angle of the turn signal lever. In this case, when the operation angle of the turn signal lever is operated larger than the determination angle for determining right / left turn, it is determined that right / left turn is performed.

Upon detecting a right or left turn of the vehicle 10, the right / left turn detection means 154 outputs a change signal to the display device 14 to change the detection area from straight traveling to right / left turning. Further, the right / left turn detecting means 154 stores a determination speed Vb for distinguishing a pedestrian from a following vehicle such as a motorcycle when turning right / left. The judgment speed Vb is a speed for judging the approach of an object that is faster than a pedestrian, that is, a motorcycle approaching from the rear side of the vehicle 1.
It is set to 3.6 km / h.

The display device 14 displays the vehicle 10 based on the change signal from the right / left turn detection means 154 as shown in FIG.
When turning left, the detection area E2 is shifted to the detection area E3, and the vehicle 1
At the right turn of 0, the detection area E1 is changed to the detection area E4. The detection areas E3 and E4 are main detection areas for detecting a following vehicle when turning right and left, and the detection areas E1 and E4
2, respectively, are set on the left and right rear sides of the vehicle 10,
In the vehicle traveling direction Y and the distance Ly ₂ toward the rear from the rear end of the vehicle 10, in the vehicle width direction is set by the rectangular area formed by the distance Lx ₂ towards the outside of the vehicle body side wall. The distance Ly ₂ at the time of turning right and left is a distance at which it is difficult for the driver to confirm the motorcycle approaching from the rear side by the rearview mirror, and the distance Lx ₂ comes closer from the rear side at the time of turning right and left. This is the distance at which the motorcycle may be involved due to the inner wheel difference of the vehicle 10. In this embodiment, the distance Ly ₂ to 5 m, the distance Lx ₂ are respectively set to 1.5 m.

The collision avoidance judging means 152 stores a map shown in FIG. 6 for judging whether a collision avoidance by a following vehicle is possible when the vehicle 10 changes lanes. The map shown in FIG. 6 shows the relationship between the relative speed Δv and the inter-vehicle distance D. The horizontal axis shows the relative speed Δv (km / h), and the vertical axis shows the inter-vehicle distance D (m). In the figure, reference symbol M represents a threshold line indicating a contact limit between the vehicle 10 and the following vehicle. Here, while the following vehicle is running at the relative speed Δv, the driver of the following vehicle can use a normal driving technique. In vehicle 10
Distance D considered to be able to avoid contact with the vehicle
Is set as the limit value. That is, the threshold line M
In the region above, it is considered possible to avoid contact between the vehicle 10 and the following vehicle, and in the region below the threshold line M, the vehicle 1
It can be considered that there is a risk of contact between 0 and the following vehicle.

The threshold line M is calculated by the following equation. M = Tm · Δv + To · Δv−1 / 2α · (Δv) ² where Tm is the action time of the driver of the vehicle 10, that is, after the driver of the vehicle 10 starts to have an intention to change lanes. The time to act (operate the turn signal lever) is represented by To, and To is the reaction time of the driver of the following vehicle, that is, the time from when the driver of the following vehicle views the turn signal of the vehicle 10 to when the driver steps on the brake. Represents time, α
Represents the general deceleration during braking. In the present embodiment, the action time Tm is set to 0 in consideration of the case where the driver of the vehicle 10 operates the turn signal lever in the shortest time. The reaction time To of the driver during driving is set to a time with a sufficient margin during normal driving, for example, about 1 second. As the deceleration α, a deceleration generated by braking performed by a general driver during normal driving is used.

The following vehicle is located in the detection areas E1 and E2 by the alarm determination means 151, and the following vehicle is
Is detected, the collision avoidance determination means 152 detects whether or not the vehicle 10 changes lanes based on the outputs from the vehicle speed sensor 16 and the turn signal switch 17. When changing lanes,
In this state, when the vehicle 10 changes lanes in front of the following vehicle, the vehicle 1 of the following vehicle is braked by the following vehicle.
It is determined whether collision to zero can be avoided based on the map.

The collision avoidance judging means 152 is based on the outputs of the relative distance calculating means 131 and the relative speed calculating means 132 (the inter-vehicle distance D and the relative speed Δv input via the alarm judging means 151). Reference point p ₀ (X ₀ ,
If Y ₀ ) is located in an area above the threshold line M on the map, it is determined that contact of the following vehicle with the vehicle 10 can be avoided, and no drive signal is output to the alarm unit 8. .

When the reference point p ₀ (X ₀ , Y ₀ ) of the following vehicle is located in the area below the threshold line M on the map, it is determined that there is a risk of contact between the vehicle 10 and the following vehicle. . Further, when the turn signal switch 17 is operated in the direction of the following vehicle in a state where there is a possibility of contact between the vehicle 10 and the following vehicle, the driving signal for illuminating the red light 21 and sounding the buzzer 22 is issued by the alarm means. 8 to warn the driver.

When the following vehicle enters the detection areas E1 and E2, the passage determining means 153 determines whether or not the following vehicle can pass the side of the vehicle 10 before the vehicle 10 changes lanes. The threshold line M1 is stored. The threshold line M1 is stored on the map shown in FIG. 6, and the driver of the vehicle 10 performs the lane change operation when the relative speed Δv when the following vehicle approaches the vehicle 10 is relatively large. Is performed to determine whether or not the following vehicle passes the vehicle 10. Threshold line M
In an area of 1 or less, while the driver of the vehicle 10 is performing a lane change operation, a following vehicle overtakes the vehicle 10, and in an area above the threshold line M1, the driver of the vehicle 10 changes the lane. It is impossible for the following vehicle to overtake the vehicle 10 because the time for the following vehicle to pass the vehicle 10 is longer than the time for performing the operation.

The following vehicle is positioned within the detection areas E1 and E2 by the alarm determination means 151, and the following vehicle is
When it is detected that the vehicle 10 is approaching, when the vehicle 10 attempts to change lanes, the passage determination unit 153 determines whether the following vehicle can pass the vehicle 10 before the vehicle 10 changes lanes. The determination is made based on the threshold line M1.

The passage determining means 153 includes the outputs of the relative distance calculating means 131 and the relative speed calculating means 132 (the inter-vehicle distance D input via the warning determining means 151 and the relative speed Δ).
Based on v), the reference point p ₀ (X ₀ , Y ₀ ) of the following vehicle
However, when it is located in an area above the threshold line M1 on the map, it is determined that it is impossible to pass the following vehicle 10. At this time, when the turn signal switch 17 is further operated in the direction of the following vehicle, a drive signal for turning on the red light 21 is output to the alarm means 8 and a drive signal for sounding the buzzer 22 is output to the alarm means 8. And warns the driver. On the other hand, the reference point p of the following vehicle
_{When 0} (X ₀ , Y ₀ ) is located in an area below the threshold line M1 on the map, the following vehicle overtakes the vehicle 10 while the driver of the vehicle 10 is performing the lane change operation. No drive signal is output to the alarm means 8.

Next, the alarm control by the controller 15 will be described with reference to the flowchart shown in FIG. The controller 15 starts an alarm control after checking each function and determining a failure according to turning on of an engine key (not shown). First, in the subroutine a, an alarm control for preventing contact with a following vehicle when changing lanes is performed.

First, in step a1, it is determined whether the vehicle 10 is going straight or turning right or left based on the speed V1 of the vehicle 10. Vehicle speed sensor 1
6, the vehicle speed V1 is detected, and this vehicle speed V1 is compared with the judgment speed Va at the time of turning right or left. If the vehicle speed V1 is equal to or lower than the determination speed Va, it is determined that one of right and left turns is to be performed, and the process proceeds to step b1. If the vehicle speed V1 is higher than the determination speed Va, the vehicle 10 is determined to travel straight, and step a2 is performed. Proceed to. In this embodiment, the determination speed Va is 20 km / h.
Is set to

In step a2, the detection area behind the vehicle 10 is set as the detection areas E1 and E2 for straight traveling. That is, as shown in FIG. 7, in the vehicle traveling direction Y, the distance Ly ₁ from the rear end of the vehicle 10 to the rear, and the vehicle width direction X
In set as the rectangular region formed by the distance Lx ₁ toward the outside of the vehicle body side wall, the process proceeds to step a3. In this embodiment, the Lx ₁ to 10 m, are set respectively Ly ₁ to 4m.

In step a3, the alarm determining means 151 determines whether or not the following vehicle enters the detection areas E1 and E2 and approaches the vehicle 10. Here, the reference point p ₀ (X ₀ , Y ₀ ) of the succeeding vehicle in the area e0 is called, and this reference point p ₀ (X ₀ , Y ₀ ) is used as the detection area E1,
It is determined whether or not it is within E2, and the reference point p ₀ (X ₀ , Y
₀ ) is within the detection areas E1 and E2, the reference point p ₀
A relative speed Δv of (X ₀ , Y ₀ ) with respect to the vehicle 10 is calculated, and a change in the relative speed Δv is detected. If the change in the relative speed Δv decreases, it is determined that the following vehicle approaches the vehicle 10 and the process proceeds to step a5. Conversely, if the change in the relative speed Δv increases, it is determined that the following vehicle moves away from the vehicle 10. At the same time, it is determined that no alarm is required, and the process proceeds to step a4. The reference point p ₀ (X ₀ , Y ₀ )
Is not in the detection areas E1 and E2, it is determined that no alarm is necessary, and the process proceeds to step a4. The approach of the following vehicle to the vehicle 10 may be determined based on a change in the inter-vehicle distance D instead of a change in the relative speed Δv.

In step a4, no drive signal for issuing various warnings is output to the warning means 8. That is, even if the vehicle 10 changes lanes, the following vehicle can be prevented from contacting the vehicle 10, so that no warning is issued to the driver. Therefore,
The vehicle 10 can safely change lanes. Thereafter, the process returns to step a1.

On the other hand, in step a5, the passage determining means 153 determines whether or not the following vehicle can pass.
The reference point p ₀ of the following vehicle on the map shown in FIG. 6 based on the inter-vehicle distance D and the relative speed Δv between the current vehicle 10 and the following vehicle.
(X ₀ , Y ₀ ) (not shown) is compared with a threshold line M 1 on the same map, and the reference point p ₀ (X ₀ , Y ₀ ) is in an area above the threshold line M 1. Sometimes, it is determined that it is impossible for the following vehicle to overtake the vehicle 10, and the process proceeds to step a6. When the reference point p ₀ (X ₀ , Y ₀ ) is in the area below the threshold line M 1, the following vehicle passes the vehicle 10 while the driver of the vehicle 10 is performing the lane change operation. Is determined to be unnecessary, and the process proceeds to step a4.

In step a6, the collision avoidance determination means 15
According to 2, it is determined whether collision avoidance by a following vehicle is possible when the vehicle 10 changes lanes. Current vehicle 10
6 based on the inter-vehicle distance D and the relative speed Δv between the vehicle and the following vehicle
A reference point p ₀ (X ₀ , Y ₀ ) on the map shown in FIG.
Is compared with a threshold line M on the map shown in FIG. 6, and when the reference point p ₀ (X ₀ , Y ₀ ) is in a region above the threshold line M, the vehicle 10 and the following vehicle It is determined that contact avoidance is possible, and it is determined that no alarm is required, and the process proceeds to step a4. When the reference point p ₀ (X ₀ , Y ₀ ) is in the area below the threshold line M, it is determined that there is a risk of contact between the vehicle 10 and the following vehicle, and the process proceeds to step a7.

In step a7, in the detection areas E1 and E2, the amber colored lamp 20 on the side where the following vehicle approaches.
Is turned on, for example, when a following vehicle is present in the detection area E1, the right amber light 20 is turned on to warn the driver that the following vehicle is approaching from behind the right side of the vehicle 10. The process proceeds to step a8.

At step a8, it is determined whether or not the vehicle 10 changes lanes to the side where the following vehicle approaches.
That is, in the present embodiment, the turn signal switch 17
When the input of the turn signal signals W _R is detected from the processing proceeds to step a9. If the side on which the following vehicle is approaching the vehicle 10 on the opposite side is attempting to change lanes, or turn signal signals W _R, when there is no input of W _L, the process returns to step a1. Note that control when changing lanes to the right or left is symmetrical to the right and left, and is performed in the same manner. Therefore, in the present embodiment, lane changes to the right will be described, and description of lanes changed to the left will be omitted.

In step a9, the red light 21 on the side where the vehicle 10 is about to change lanes is turned on. In the present embodiment, the red light 21 on the right side of the vehicle 10 is turned on, and the buzzer 22 is sounded, so that the vehicle 10 The driver is notified that the following vehicle is approaching from the rear side. When the turn signal switch 17 is returned, the red light 21 and the buzzer 22 are turned off and stop sounding. Thus, a series of alarm control at the time of lane change is completed, and the process returns to step a1.

In the subroutine "b", control relating to prevention of contact with a following vehicle, particularly a motorcycle, when turning right or left is performed. Note that the control at the time of turning right or left is symmetrical to the left and right and is performed in the same manner. Therefore, the control at the time of turning left will be described here, and the description of the control at the time of turning right will be omitted. Step b
In step 1, the right / left turn detecting means 154 changes the detection area behind the vehicle 10 from the detection areas E1 and E2 when traveling straight ahead to the detection areas E3 and E4 when turning right and left. That is, as shown in FIG. 8, each distance Ly ₂ is defined by a distance Ly ₂ extending rearward from the rear end of the vehicle 10 in the vehicle traveling direction Y and a distance Lx ₂ extending outward from the vehicle body side wall in the vehicle width direction X. The area is set as a rectangular area, and the process proceeds to step b2. In this embodiment, the Lx ₂ to 5 m, are set respectively Ly ₂ to 1.5 m.

At step b2, the entry of the motorcycle into the detection areas E3, E4 is detected. The reference point p ₀ (X ₀ , Y ₀ ) of the motorcycle in the area e0 is called, and this is called the detection area E3.
It is determined whether or not it is within E4, and the reference point p ₀ (X ₀ , Y
₀ ) is within the detection areas E3 and E4, step b
4, the reference point p ₀ (X ₀ , Y ₀ ) is set to the detection areas E3 and E
If it is not within 4, it is determined that no alarm is required, and the process proceeds to step b3.

In step b3, no drive signal for issuing various warnings is output to the warning means 8. That is, even if the vehicle 10 turns right or left, it is possible to avoid contact with the two-wheeled vehicle traveling on the rear side of the vehicle 10, so that no warning is issued to the driver. Therefore, the vehicle 10 can safely turn right and left. Thereafter, the process returns to step a1.

In step b4, the possibility of contact with the motorcycle at the time of turning right or left is determined. The relative speed Δv between the vehicle 10 and the motorcycle is compared with a determination speed Vb for determining the possibility of contact at the time of turning right or left. The relative speed Δv is equal to the determination speed Vb
As described above, when approaching the vehicle 10, it is determined that there is a possibility of contact, the process proceeds to step b5, and the relative speed Δ
v is lower than the determination speed Vb, or when the two-wheeled vehicle
If you move away from it, it is determined that there is no possibility of contact,
Proceed to step b3. In this embodiment, the determination speed V
b is set to 3.6 km / h.

In step b5, it is determined whether or not the vehicle 10 makes a right or left turn on the side where the motorcycle approaches. For example, when the left rear of the vehicle 10 motorcycle approaching, when the input from the turn signal switch 17 of the turn signal signals W _R is detected, the process proceeds to step a9. When the vehicle 10 is about to make a right or left turn on the side opposite to the side where the motorcycle approaches, for example, when the motorcycle 10 approaches from the left rear of the vehicle 10, when the vehicle 10 makes a right turn, or a turn signal. If there is no input signal W _R, W _L, the process proceeds to step b3.

[0056]

As described above, according to the first aspect of the present invention, the following vehicle is detected by the alarm determining means behind the own vehicle, and the following vehicle approaches the own vehicle. A determination is made as to whether or not the vehicle comes, and the collision avoidance determination means determines whether it is possible to avoid a collision of the following vehicle with the own vehicle by braking the following vehicle. You can confirm that the following vehicle is approaching from the rear side of your own vehicle, and if there is a following vehicle on the rear side, if the lane is changed, the following vehicle will avoid collision with your own vehicle You can check if it is possible. Therefore, when it is possible to avoid a collision of the following vehicle with the own vehicle, it is determined that the lane can be changed, so that useless warning can be reduced.

According to the second aspect of the present invention, when the own vehicle attempts to change lanes, if the passage determining means determines that the following vehicle cannot pass through the own vehicle sideways, the warning means is used. When a warning is issued, and when the passage determining means determines that the following vehicle can pass by the side of the own vehicle, no warning is issued by the warning means, so that useless warning can be reduced.

According to the third aspect of the invention, when the right or left turn detecting means detects a right turn or a left turn of the own vehicle, the succeeding vehicle detecting means detects the following vehicle in the detected turning direction of the own vehicle. Since the area is narrowed, when turning right or left, the detection of unnecessary objects other than the following vehicle, that is, the unnecessary objects outside the road can be reduced, the detection accuracy of the following vehicle can be improved, and highly reliable detection can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration of a rear side alarm device of a vehicle to which the present invention is applied.

FIG. 2 is a plan view of a vehicle equipped with the rear side alarm device of the present invention.

FIG. 3 is an enlarged side view of a delta zone provided with amber and red lights.

FIG. 4 is a functional block diagram of a control system of the rear side alarm device of the present invention.

FIG. 5 is an enlarged view of a display unit that displays a detection state of the rear side of the vehicle.

FIG. 6 is a characteristic diagram showing a relationship between an inter-vehicle distance and a relative speed used by a control system in the rear side alarm device of the present invention.

FIG. 7 is an explanatory diagram of a detection area for lane change used by the rear side warning device of the present invention.

FIG. 8 is an explanatory diagram of a detection area for turning right or left used by the rear side alarm device of the present invention.

FIG. 9 is a flowchart of alarm control by the control system of the rear side alarm device of the present invention.

FIG. 10 is an explanatory view of a conventional driver's view area during normal driving.

[Explanation of symbols]

Reference Signs List 8 warning means 9 rear side warning device 10 vehicle 12 scan laser radar 13 radar drive circuit 131 relative distance calculation means 132 relative speed calculation means 16 vehicle speed sensor 17 turn signal switch 14 display device 15 controller 151 warning determination means 152 collision avoidance determination means 153 Passage determination means 154 Right / left turn detection means D Inter-vehicle distance Δv Relative speed E1 to E4 Detection area V1 Vehicle speed Va, Vb Determination speed W _L Left turn signal W _R Right turn signal

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Watanabe 5-33-8 Shiba, Minato-ku, Tokyo, Mitsubishi Motors Corporation

Claims (3)

[Claims] 1. A rear side alarm device for a vehicle that detects a following vehicle running on the rear side of the host vehicle and warns the driver, a following vehicle detecting means for detecting the following vehicle, A relative distance calculating unit that calculates a relative distance between the host vehicle and the following vehicle from an output of the following vehicle detecting unit; and a relative speed between the host vehicle and the following vehicle from an output of the following vehicle detecting unit. Relative speed calculating means; determining whether or not to issue an alarm to the driver based on respective outputs of the relative distance calculating means and the relative speed calculating means when the following vehicle approaches the own vehicle. An alarm determining unit that performs a braking operation on the following vehicle based on the outputs of the relative distance calculating unit and the relative speed calculating unit when the own vehicle changes lanes in front of the following vehicle. of Serial collision avoidance determination means for determining whether a collision of the vehicle can be avoided, it is determined that an alarm by the alarm determination means, and,
Warning means for warning the driver when the collision avoidance determining means determines that collision avoidance by braking of the following vehicle is impossible. Side alarm. 2. A rear side alarm device for a vehicle that detects a following vehicle running on the rear side of the host vehicle and warns the driver, the following vehicle detecting means detecting the following vehicle; A relative distance calculating unit that calculates a relative distance between the host vehicle and the following vehicle from an output of the following vehicle detecting unit; and a relative speed between the host vehicle and the following vehicle from an output of the following vehicle detecting unit. Relative speed calculating means; determining whether or not to issue an alarm to the driver based on respective outputs of the relative distance calculating means and the relative speed calculating means when the following vehicle approaches the own vehicle. Alarm determination means for performing, before the own vehicle changes lanes, based on each output of the relative distance calculation means and the relative speed calculation means when the own vehicle attempts to change lanes in front of the following vehicle. To The following vehicle is determined to perform the determining passage judgment means whether it is possible to pass through the side of the vehicle, an alarm by the alarm determination means, and,
A warning means for warning the driver when the passing determination means determines that passage of the following vehicle is not possible; and a rear side warning device for the vehicle, comprising: . 3. When detecting that the vehicle speed of the host vehicle is equal to or lower than a predetermined value and that the turn lever is operated,
Right and left turn detecting means for detecting a right turn or a left turn of the own vehicle, and when the right or left turn of the own vehicle is detected by the right or left turn detecting means, the subsequent vehicle detecting means detects the detected self turn. 3. The rear side warning device according to claim 1, wherein a detection area of the following vehicle in a folding direction of the vehicle is narrowed.