JP2002372584A - Rear side approach alarm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear side approach alarm device constituted not to give an alarm to vehicles existing in a lane further next to a lane change place when changing the lane. SOLUTION: An ECU acquires own vehicle speed V from a vehicle speed sensor 2, a steering angle θ from a steering angle sensor 3, and an other-vehicle position (X, Y), relative speed Vr and the state of a winker switch 4 from a millimeter wave radar 1. On the basis of information input, a rear vehicle in an own vehicle travel lane, and a rear vehicle in an adjoining lane in a lane change direction from the own vehicle travel lane are selected as an alarm vehicle group, and the updating of the alarm object vehicle group is inhibited until detecting the lane change by the winker switch 4. Alarm output processing by indicators 6, 7 and buzzers 8, 9 is performed on the basis of the alarm object vehicle group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear side approach warning device for assisting safety confirmation of a rear side of a vehicle.

[0002]

2. Description of the Related Art In recent years, various auxiliary devices have been proposed for safety confirmation performed by a driver when merging or changing lanes. For example, when the host vehicle attempts to change lanes, a radar device arranged to monitor the rear side of the host vehicle detects the rear vehicle, and detects the vehicle speed and yaw rate of the host vehicle, or a GPS receiver. Alternatively, the lane shape of the road on which the own vehicle is traveling is estimated from data measured using the imaging device, and a vehicle detected on the rear side of the own vehicle exists in an adjacent lane where the own vehicle is about to change lanes. It is determined whether or not the vehicle is in the adjacent lane, and if it is determined that the vehicle is in the adjacent lane, the driver is notified from the distance and the relative speed between the vehicle and the vehicle according to the degree of approach of the vehicle to the vehicle. A rear side approach warning device is known (JP-A-6-258426).
And JP-A-11-328591.

[0003]

However, in the above-mentioned conventional rear side approach warning device, the rear side is always set as a warning target area based on the position of the vehicle, so that the vehicle changes lanes due to overtaking or the like. When it starts, the warning target area also moves accordingly, and if there is a vehicle in the lane next to the lane to which the lane is changed, this vehicle has no effect on the own vehicle at this time However, there is a problem that the driver may be notified.

[0004] The present invention has been made in view of the above-mentioned conventional problems, and does not issue a warning to a vehicle existing in a lane next to the lane change destination when the lane is changed. It is an object to provide an alarm device.

[0005]

According to the first aspect of the present invention,
In order to achieve the above object, a vehicle existing behind the host vehicle is detected by an image processing device or a radar device that processes an image captured in the rear, and a driver is notified when the vehicle is approaching the host vehicle. Rear side approach warning device
A lane change detecting means for detecting the start and end of the driver's lane change operation, and when the lane change detection means detects the start of the lane change, the vehicle behind the own vehicle travel lane and the vehicle behind the adjacent lane in the lane change direction are set And a warning target vehicle selection unit that prohibits the updating of the warning target vehicle group until the lane change detection unit detects the end of the lane change. The gist is to notify the driver when any vehicle is approaching the host vehicle.

According to a second aspect of the present invention, there is provided a rear side approach warning device according to the first aspect, wherein
The warning target vehicle selecting means, even when the lane change detecting means detects the start of the lane change and detects the end of the lane change, enters the warning target vehicle group in the lane in the lane change direction. If a new vehicle is detected, the vehicle is added to the group of vehicles to be warned.

[0007]

According to the first aspect of the present invention, a vehicle existing on the rear side of the vehicle is detected by an image processing device or a radar device for processing an image captured rearward, and the vehicle is detected as a vehicle. A rear side approach warning device that notifies the driver when approaching, a lane change detecting means for detecting the start and end of the driver's lane change operation, and a lane change detecting means for detecting the start of the lane change operation. A vehicle behind the vehicle lane and a vehicle behind the adjacent lane in the lane change direction are selected as a group of vehicles to be warned, and updating of the group of vehicles to be warned is prohibited until the lane change detection unit detects the end of the lane change. Warning target vehicle selection means, and notifies the driver when any of the vehicles included in the warning target vehicle group is approaching the host vehicle, so that the lane change of the host vehicle starts. The vehicle behind the own vehicle traveling lane and the vehicle behind the adjacent lane in the lane change direction are selected as a group of vehicles to be warned, and until the end of the lane change, only vehicles in this group of vehicles to be warned are notified. There is an effect that it is possible to prevent erroneous notification to vehicles behind two or more lanes at the start of the change.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the warning target vehicle selecting means includes a lane change detecting means for detecting a lane change start and a lane change end. Even before the detection, in the lane in the lane change direction, if a new vehicle that is not in the group of vehicles to be warned is detected, the vehicle is added to the group of vehicles to be warned. In addition, even when a vehicle that is not included in the group of vehicles to be warned enters the lane to which the lane has been changed while the host vehicle is changing lanes, the vehicle can be notified.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an embodiment of a rear side approach warning device according to the present invention. In FIG. 1, a rear side approach warning device includes a millimeter wave radar 1 that detects a vehicle existing on the rear side of the host vehicle, and a turn signal switch as a lane change detection unit that detects the start and end of a lane change operation by a driver. 4 and when the start of the lane change is detected from the turn signal switch 4, the rear vehicle of the own vehicle traveling lane and the rear vehicle of the adjacent lane in the lane change direction are selected as a group of vehicles to be warned, and the lane change end is detected from the turn signal switch 4. An electric control unit (hereinafter abbreviated as ECU) 10 as an alarmed vehicle selecting means for prohibiting the updating of the alarmed vehicle group until the detection is performed, and one of the vehicles included in the alarmed vehicle group is automatically detected. Indicator (right) 6, indicator (left) 7, buzzer (right) 8, buzzer to notify driver when approaching vehicle It is provided with a (left) 9, a. Further, the ECU 10 is connected to a vehicle speed sensor 2 for measuring a speed in the traveling direction of the own vehicle (hereinafter, own vehicle speed) and a steering angle sensor 3 for measuring a steering angle of the steering wheel.

FIG. 2 is a plan view of the periphery of the vehicle for explaining the mounting state of the millimeter wave radar 1 and the measurement of the vehicle behind. The millimeter-wave radar 1 is attached to the center of the rear end of the vehicle as shown in FIG. 2, and measures a relative distance, a relative speed, and a relative angle with an object existing on the rear side of the vehicle. Here, the relative velocity cannot be directly measured by the millimeter wave radar 1, but can be calculated as a temporal change of the relative distance.

In addition to radars using millimeter waves, radars using laser light are known as distance measuring means, and these means may be used. When a radar having a narrow field of view is used, a plurality of radars may be mounted with the distance measurement range shifted.

Further, in place of the millimeter-wave radar 1, a camera for picking up an image behind the vehicle and processing the image by the camera to detect the presence and distance of the rear side vehicle and the approach of the rear side vehicle. An image processing device may be used.

The ECU 10 performs arithmetic processing based on input signals from a vehicle speed sensor 2, a steering angle sensor 3, and a turn signal switch 4 for giving a right or left direction instruction, in addition to the millimeter wave radar 1, and an indicator. 6 and 7 and buzzers 8 and 9 are controlled.

FIG. 3 is a schematic view in front of the driver's seat for explaining the arrangement of the indicators 6, 7 and the buzzers 8, 9.
The indicators 6 and 7 are two-color light emitting diodes (LEDs) that emit green or red light, and are installed below the left and right A pillars 30 as shown in FIG. This informs the driver of the sight of the driver looking at the rear side through the door mirror or side window.

The buzzers 8 and 9 are provided below the left and right A pillars 30 as shown in FIG. By generating an alarm sound, the driver's consciousness is directed to the left or right side door mirror 31, the side window and the indicator, and the safety confirmation to the left or right rear side is urged.

Next, referring to the flowchart of FIG.
The processing procedure of the present embodiment will be described. The indicators 6 and 7 and the buzzers 8 and 9 are symmetrically attached to the left and right sides of the vehicle, and a warning by the vehicle on the right rear side is given by the indicators (right) 6 and the buzzer (right) 8 and the left rear side. The warning by the one-way vehicle is performed by the indicator (left) 7 and the buzzer (left) 9, but the same processing is performed except that the direction is changed between left and right. Therefore, in the description of the processing procedure, the left side is omitted and only the right side is performed. I will.

In FIG. 4, when the rear side approach warning device is first turned on, the process starts from MAIN.

First, an initialization process is performed to empty the data of a group of vehicles to be warned representing a group of vehicles that can be a warning target, and set a data update flag to 1 (step S101).
When the data update flag is 1, it indicates that the data of the group of vehicles to be alerted may be entirely updated, and when the data update flag is 0, it indicates that the data of the group of vehicles to be alerted must not be entirely updated.

Next, by an information input processing subroutine,
Own vehicle speed V, steering angle θ, other vehicle position (X, Y), relative speed V
r, the state of the turn signal switch 4 is acquired (step S110), and based on these information inputs, the vehicle behind the own vehicle travel lane and the vehicle behind the adjacent lane in the lane change direction from the own vehicle travel lane are alerted vehicles. Until the lane change is detected from the turn signal switch 4, a warning target vehicle selection process is performed to prohibit the updating of the warning target vehicle group (step S <b> 120). An alarm issuance process is performed by a buzzer (step S130), and the process proceeds to step S130.
Return to 110.

FIG. 5 is a flowchart for explaining the details of the information input processing subroutine (step S110). First, the own vehicle speed V is obtained from the number of vehicle speed pulses per unit time from the vehicle speed sensor 2 (step S111), and the steering angle θ from the steering angle sensor 3 is obtained (step S11).
2). Next, the ECU 10 communicates with the millimeter-wave radar 1, and the relative distance L from the own vehicle to each object identified by the millimeter-wave radar 1, the angle φ from the vehicle center axis, and the relative speed V
_r (following vehicle speed-own vehicle speed) is acquired.

Here, in order to reduce the processing load and perform high-speed processing, an object that satisfies the following equation (1) is removed from the measured objects because it is an oncoming vehicle or a stationary object. Only the data of the vehicle traveling in the same direction as above is left.

[0022]

V _r > −V (1) Further, the position information of the vehicle measured by the millimeter wave radar 1 is shown in FIG.
Since this is a polar coordinate system based on (L, φ) as shown in (1), this is converted into an orthogonal coordinate system (X, Y) by equations (2) and (3) (step S113).

[0023]

X = L · sin φ (2) Y = −L · cos φ (3) Next, in order to detect the start of the lane change operation by the driver, the operating state of the turn signal switch 4 is acquired and information is input. Ends the process and returns to the main routine (Step S11)
4).

Next, the process proceeds to the alarm target group selection process (step S120), which will be described with reference to the subroutine of FIG.

First, for the road shape estimation, the turning radius R of the own vehicle is obtained by the following equation (4) based on the own vehicle speed V and the steering angle θ, and this is estimated as the road radius R (step S121). .

[0026]

R = (1 + A · V ² ) · N / θ (4) Here, A is a stability factor specific to the vehicle, for example, 0.002. N is the product of the wheelbase and the steering gear ratio specific to the vehicle, for example, 50. The polarity of θ is positive for steering in the right direction and negative for steering in the left direction. Therefore, as for the polarity of R, positive indicates a right curve and negative indicates a left curve.

Next, a lane determination is performed for each vehicle whose distance has been measured (step S122). This lane determination method will be described with reference to FIG.

FIG. 10 shows that the vehicle 20 is running on the left lane of a right curve road having two lanes, a left lane sandwiched between white lines 41 and 42 and a right lane sandwiched between white lines 42 and 43. Is shown.

Assuming that the center coordinate of the own lane at the same Y position as a certain rear vehicle 44 (X, Y) is (Xc, Y),
Equations (5) and (6) can be calculated.

[0030]

Xc = R− (R ² −Y ² ) ^1/2 (R> 0) (5) Xc = R + (R ² −Y ² ) ^1/2 (R <0) (6) , | R |> | Y |> 0.

Then, the coordinates of the left end of the own lane are represented by ( _XL1 ,
Y), the coordinates at the right end of the own lane are (X _R1 , Y), and the coordinates at the right end of the adjacent lane are (X _R2 , Y), X _L1 , X _R1 and X _R2 are

Equation 5] _{X L1 = X c -0.5W ... (} 7) X R1 = X c + 0.5W ... (8) X R2 = X c + 1.5W ... (9) Equation (7), (8) , (9).

Here, W is a value set as a lane width, for example, 3.5 m. Originally, the lane width W is determined in the direction perpendicular to the lane, but here, for the sake of simplicity, the values are set in the direction parallel to the X-axis for convenience. When the X coordinate of the rear vehicle satisfies Expression (10), the vehicle in the own lane, and when the X coordinate satisfies Expression (11), the vehicle in the right lane, Expression (1)
If the condition 2) is satisfied, it means that the vehicle is in a non-adjacent lane on the right.
Each can be determined.

[0033]

X _L1 <X ≦ X _R1 (10) X _R1 <X ≦ X _R2 (11) X _R2 <X (12) This lane determination is performed for all vehicle data, and the result is determined for each lane. Classify into.

Next, it is determined whether or not the turn signal switch 4 is ON (step S123). If the turn signal switch 4 is ON, the data update flag is confirmed (step S124). The process proceeds to step S125 to update the vehicle group. In step S125, the data of the warning target vehicle group is completely updated to the data of the own lane vehicle and the data of the right lane vehicle. Further, the data update flag is changed to 0, and the process returns to the main routine. By this processing, the entire update is not performed until the turn signal switch 4 is turned off. Therefore, as shown in FIG. 8, the vehicle (B), which is in the lane two adjacent to the lane at the start of the lane change of the own vehicle (A), is in the lane change (A ') and the adjacent lane vehicle (B'). Even if it comes to recognize that there is no alarm.

When the data update flag is 0 in step S124, the vehicle data in the own lane is compared with the vehicle group data to be warned to determine whether there is a new vehicle in the own lane (step S126). ), If it does not exist, return to the main routine. If there is a new vehicle in the own lane, the vehicle data is added to the vehicle group to be warned (step S127), and the process returns to the main routine.

According to this processing, as shown in FIG. 9, the vehicle (C) which is not included in the group of vehicles to be warned when the turn signal switch 4 is ON as shown in FIG. When entering the same lane as the destination during the change (C ')
However, an alarm can be issued. In addition, since the vehicle in the adjacent lane is not added, the vehicle is changing lanes with respect to the vehicle (B) that is in the two adjacent lanes at the start of the lane change (A) as shown in FIG. Even if the vehicle is recognized as the adjacent lane vehicle (B ') in (A'), no alarm is issued.

On the other hand, when the turn signal switch 4 is OFF in step S123, it is sufficient to assist the driver in determining whether or not the lane can be changed at that time. It is completely updated every cycle. Therefore, in step S128, a process of updating the alarm target vehicle group data to the data of the own lane vehicle and the data of the right lane vehicle is performed. Then turn signal switch 4
To update only once when is turned on,
The data update flag is set to 1 and the process returns to the main routine.

Next, the process proceeds to an alarm issuing process (step S1).
30), this subroutine is shown in FIG. In FIG. 7, first, the inter-vehicle time t is obtained by dividing the relative distance L by the relative speed _Vr for each vehicle registered in the group of vehicles to be warned (step S131). This inter-vehicle time t corresponds to the time required for the vehicle behind to reach the rear end of the own vehicle when the calculated relative speed continues thereafter.

Next, a minimum value t _min is searched for and obtained for the inter-vehicle time t for each vehicle (step S13).
2). Next, t _min is a predetermined value, for example, 2 sec.
Is determined (step S133).
If the time exceeds sec, it is not necessary to actively provide information to the driver, so the green indicator is turned on and the buzzer does not sound (step S134).

On the other hand, if t _min is less than 2 seconds, it is determined whether or not the turn signal switch 4 is ON (step S135). If the turn signal switch 4 is OFF, the indicator lights red because an approaching vehicle is present. However, it is determined that the driver has no intention to change lanes, and the buzzer does not sound (step S136).

If t _min is less than 2 sec and the turn signal switch 4 is ON, it is determined that the driver intends to change lanes even though an approaching vehicle is present. By performing the notification, the driver is urged to confirm safety on the rear side (step S137).

With the above processing, the subroutine of the alarm issuance processing is terminated, and after returning to the main routine, the flow returns to step S110 again.

The information input process in step S110, the alarm vehicle group selection process in step S120, and step S120
The 130 alarm issuance process is repeated for a predetermined period, for example, a period of 100 msec in accordance with the radar ranging period, while the ignition switch is ON.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of a rear side approach warning device according to the present invention.

FIG. 2 is a plan view of the vicinity of a vehicle showing a state of attachment of a radar and measurement of a vehicle behind.

FIG. 3 is a view around a driver's seat showing an attached state of an indicator and a buzzer.

FIG. 4 is a flowchart of a main routine for explaining the operation of the embodiment.

FIG. 5 is a flowchart illustrating an information input processing subroutine of the embodiment.

FIG. 6 is a flowchart illustrating an alarm target vehicle group selection processing subroutine of the embodiment.

FIG. 7 is a flowchart illustrating an alarm issuing process according to the embodiment.

FIG. 8 is a diagram illustrating an effect in the embodiment.

FIG. 9 is a diagram illustrating an effect in the embodiment.

FIG. 10 is a diagram illustrating a lane determination method according to the embodiment.

[Explanation of symbols]

 1 millimeter wave radar 2 vehicle speed sensor 3 steering angle sensor 4 turn signal switch 6 indicator (right) 7 indicator (left) 8 buzzer (right) 9 buzzer (left)

Claims (2)

[Claims] 1. An image processing device or radar device for processing an image of a rear image of a vehicle, detects a vehicle present on the rear side of the vehicle, and informs a driver when the vehicle is approaching the vehicle. A lane change detecting means for detecting start and end of a lane change operation by a driver; and a lane change direction and a vehicle behind the own vehicle traveling lane when the lane change detection means detects the start of the lane change. And selecting the vehicles behind the adjacent lane as a group of vehicles to be alerted, and selecting a vehicle to be alerted to prohibit updating of the group of vehicles to be alerted until the lane change detection unit detects the end of the lane change. A rear side approach warning device, which notifies a driver when any vehicle included in the warning target vehicle group is approaching the host vehicle. 2. The warning target vehicle selecting means, even when the lane change detecting means detects the start of the lane change and detects the end of the lane change, in the lane in the lane change direction. The rear side approach warning device according to claim 1, wherein when a new vehicle that is not included in the vehicle group is detected, the vehicle is added to the vehicle group to be warned.