JP3279176B2 - Lane departure warning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lane departure warning device, and more particularly, to a lane departure warning device that issues a warning when a vehicle is about to depart from the lane.

[0002]

2. Description of the Related Art When a vehicle is driven for a long time on a straight road such as an expressway, the driver tends to be tired and the driver's awakening degree tends to decrease. As described above, when the driver's arousal level decreases, the driver's steering operation becomes unstable, and the vehicle often runs wandering. When the vehicle staggers,
The vehicle may deviate left and right from the currently used driving lane against the driver's intention.

Therefore, in recent years, the lane side edge (white line) of the traveling lane is recognized using an imaging means such as a CCD camera, and the positional relationship between the lane side edge and the vehicle is determined based on the lane side edge information. Thus, a device that predicts the possibility that the vehicle will depart from the lane and issues an alarm to the driver has been developed. However, in such a device, since the lane departure of the vehicle is determined based on the positional relationship between the lane side edge and the vehicle, even when the driver intentionally causes the vehicle to approach the lane side edge. There was a problem that an alarm was issued and the driver felt uncomfortable.

[0004] In order to solve this problem, no alarm is issued in a situation where the driver does not need to be alerted, such as when the driver intentionally approaches the vehicle to the lane side edge. An apparatus designed to prevent the driver from feeling uncomfortable is disclosed in Japanese Patent Application Laid-Open No. HEI 6-171392.

[0005]

However, in the device disclosed in the above publication, when the driver does not intend to bring the vehicle closer to the lane side edge, the vehicle and the lane side edge are changed as in the prior art. An alarm is issued when the vehicle and the vehicle have a predetermined positional relationship, and the alarm is continued unless the vehicle and the lane side edge deviate from the predetermined positional relationship.

[0006] However, usually, when an alarm is given, the driver operates the steering wheel so as to keep the vehicle away from the lane side edge so as to avoid departure, so that the vehicle moves away from the lane side edge well. When the vehicle moves away from the lane side edge toward the center of the lane in this way, it can be considered that the deviation of the vehicle from the lane has been almost avoided. Therefore, even if the vehicle is heading toward the center of the lane, the driver still feels uncomfortable if the warning is continued until the vehicle and the lane side edge depart from the predetermined positional relationship as described above. This is not desirable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lane departure warning device capable of issuing a lane departure warning without discomfort.

[0008]

According to a first aspect of the present invention, there is provided a driving lane recognizing means mounted on a vehicle and recognizing a driving lane ahead of the vehicle. Traveling position recognition means for recognizing the traveling position of the vehicle in the traveling lane based on the lane information; and lane departure determination for determining the tendency of the vehicle to depart from within the traveling lane based on the lane information and the traveling position. and means, when the vehicle is determined to be in the departure tendency by the lane deviation determining means, and a warning means for outputting an alarm, said vehicle
The lane departure determination means is based on the distance from the lane side edge of the vehicle.
Determining the departure tendency, wherein the vehicle is in the lane
When approaching the side edge, the distance is the first predetermined distance
If the vehicle is less than
After leaving the lane side edge after becoming dislodged
Is a second predetermined distance in which the distance is smaller than the first predetermined distance.
When the distance is less than the separation, the deviation tendency is determined.

[0009]

[0010]

Therefore, when the vehicle is approaching the traveling lane side edge, it is determined that the vehicle is deviating when the distance between the vehicle and the traveling lane edge is less than the first predetermined distance. When the vehicle is separated from the traveling lane side edge, the vehicle tends to deviate if the distance between the vehicle and the traveling lane side edge is smaller than a second predetermined distance smaller than the first predetermined distance. That is, when it is determined that the vehicle has a tendency to deviate, an alarm is output. Thereafter, when the vehicle separates from the driving lane side edge, the departure tendency is earlier than when the vehicle approaches the driving lane side edge. Is canceled and the alarm is stopped.

Further, according to the invention of claim 2 , further comprising lane change signal output means for outputting a traveling lane change signal based on the intention of the vehicle driver, wherein the alarm means is provided by the lane change signal output means. When the driving lane change signal based on the driver's intention is output, the output of the warning is stopped irrespective of the information on the tendency of the vehicle to depart from the driving lane by the lane departure determining means.

Therefore, when the driving lane change signal based on the intention of the vehicle driver is output, the driver's awakening degree is determined to be high, and even if the vehicle is approaching the driving lane side edge. The alarm is not output unnecessarily. Further, the invention according to claim 3 further comprises a vehicle speed detecting means for detecting a vehicle speed, wherein the first and second predetermined distances are:
It is set according to the vehicle speed.

Therefore, the first and second predetermined distances are set according to the vehicle speed.
The separation is set, and a more detailed deviation determination is performed. For example, when the vehicle speed is high, the first predetermined distance when the vehicle is moving toward the departure tendency is set to such a value that the departure tendency is determined at an early timing. Thereby, departure avoidance of the vehicle is more reliably performed.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a vehicle 1 equipped with a lane departure warning device according to the present invention.
Is shown. As shown in the figure, the lane departure warning device mainly includes a CCD camera (traveling lane recognizing means) 2, a pair of left and right direction indicators 4 and 4, a direction instruction switch (lane change signal output means, hereinafter referred to as a direction instruction SW). ) 6, a speaker 8 as an alarm (alarm means) and an electronic control unit (hereinafter referred to as ECU) 10.

The CCD camera 2 is an image pickup device for photographing the front of the vehicle 1, and not only the object in front of the vehicle 1, but also the side edge of the traveling lane, that is, the lane as shown in the left circle in FIG. It is also possible to accurately capture a white line or a yellow line, which is a side edge of a lane on a road that separates the roads. Hereinafter, these white lines and yellow lines are simply referred to as white lines W for convenience. Turn signal 4,
Reference numeral 4 denotes a lamp for informing the surroundings of the turning direction of the vehicle 1, that is, a blinker lamp (also referred to as a blinker lamp).
It is. The direction indicator SW6 is an input switch for operating the direction indicators 4 and 4 provided near the driver's seat.
The direction instruction SW 6 can be switched between right and left around the neutral position. That is, when the driver switches the direction indicator SW6 to the right side, the right direction indicator 4 flashes, and when the direction indicator SW6 is switched to the left side, the left direction indicator 4 flashes. I have. When the vehicle 1 is traveling straight, the normal direction instruction SW 6 is automatically set to the neutral position, and in this case, the direction indicators 4 and 4 do not blink.

The loudspeaker 8 is only required to be able to transmit a warning to the driver by voice, and the loudspeaker of the audio equipment mounted on the vehicle 1 may be shared. ECU10
Is an arithmetic processing unit including a central processing unit (CPU) and a storage device such as a ROM and a RAM. The input side of the ECU 10 includes the CCD camera 2 and the direction switch 6.
And various input devices and various sensors (not shown). On the other hand, various devices (not shown) for performing various controls of the vehicle 1 are connected to the output side of the ECU 10 in addition to the direction indicators 4 and 4 and the speaker 8.

FIG. 2 shows a block diagram of the lane departure warning device. Referring to FIG. 1, the ECU 10 includes a white line recognition unit (running position recognition unit) 12, a lane deviation determination unit (lane deviation determination unit) 14, and a lane departure warning device.
Each function of the alarm output determination unit (alarm unit) 16 is provided. Therefore, when the imaging information from the CCD camera 2 and the direction instruction information from the direction instruction SW 6 are input to the ECU 10,
The arithmetic processing for lane departure recognition is performed in the ECU 10, and an alarm is output from the alarm, that is, the speaker 8, in accordance with the processing result. Thus, when it is predicted that the vehicle 1 departs from the lane carelessly, it is possible for the driver to well recognize the risk of the departure.

Referring to FIG. 3, there is shown a flowchart showing a processing routine of a lane departure warning. Hereinafter, the processing procedure and operation of the lane departure warning will be described in detail with reference to FIGS. When the vehicle 1 is running, the CCD camera 2 operates and the imaging information from the CCD camera 2 is input to the ECU 10 as shown in step S10 in FIG. In this step S10, direction instruction information from the direction instruction SW 6 is also input.

In step S12, image processing is performed based on the image pickup information (white line recognition unit 1).
2). Specifically, in this step S12, the lane side edge,
That is, the white lines W on the left and right sides of the vehicle 1 are digitized and determined as white line expressions F (R) and F (L), respectively, and based on these white line expressions F (R) and F (L), The position of the vehicle 1 in the inside is obtained. That is, the distance between the vehicle 1 and the white line W,
That is, the right distance DR and the left distance DL as shown in the circle in FIG. 1 are obtained. Normally, white line equations F (R) and F (L) are
With the position of the CCD camera 2 as the origin O, the coordinate system is set with the front-back direction of the vehicle 1 set as the X-axis and the lateral direction set as the Y-axis (see FIG. 1). Therefore, the distances DR and DL are, for example, CC
It is obtained as the distance between the D camera 2 and the white line W. In addition,
The methods of calculating the formulas F (R) and F (L) of these white lines and the distances DR and DL are known, and a detailed description thereof will be omitted.

In this manner, the vehicle 1 is controlled based on the image processing.
Is confirmed and the distances DR and DL are determined.
Next, the process proceeds to step S14. In step S14, differentiation processing of the distances DR and DL is performed. That is, in this step, the speed at which the vehicle 1 approaches the white line W, that is, the right speed d
DR and leftward speed dDL are obtained. Here, for example, when the vehicle 1 is traveling while approaching the white line W on the right side, the sign of the right speed dDR is positive (+) and the sign of the left speed dDL is negative (-). You. On the other hand, when the vehicle 1 is traveling while approaching the left white line W, these signs are reversed.

In the following steps S16 to S20, a departure from the lane of the vehicle 1 is determined (lane departure determination unit 14). First, in step S16, it is determined whether or not the vehicle 1 is moving outside the lane based on the right speed dDR and the left speed dDL. Specifically, in this determination, first, the lane width D is obtained from the distances DR and DL, and the distance from the white line W to the center position of the lane,
That is, the median value D / 2 of the lane width D is calculated. By comparing the median value D / 2 with the distances DR and DL, the vehicle 1
It is determined whether the vehicle is traveling to the right in the lane or to the left in the lane. Specifically, if the distance DR is larger than the median value D / 2 and the distance DL is small (DL <D / 2 <DR), it is determined that the vehicle 1 is traveling left of the lane. . On the other hand, if the distance DL is larger than the median value D / 2 and the distance DR is small, (DR <D / 2 <D
L), it is determined that the vehicle 1 is traveling on the right side of the lane.

In this way, when it is confirmed whether the vehicle 1 is traveling to the right of the lane or to the left of the lane, based on this information and the information of the right speed dDR and the left speed dDL, Thus, it is determined whether or not the vehicle 1 is heading outside the lane. For example, vehicle 1
Is traveling on the right side of the lane and the sign of the right speed dDR is negative (-), and when the vehicle 1 is traveling on the left side of the lane and the sign of the left direction dDR is negative (-). , It can be determined that the vehicle 1 is about to deviate from the lane to the right or left. On the other hand, when the vehicle 1 is traveling on the right side of the lane and the sign of the right speed dDR is positive (+),
And the vehicle 1 is traveling on the left side of the lane and the speed d in the left direction
When the sign of DR is positive (+), it can be determined that the vehicle 1 is heading toward the center of the lane. Then, step S16
Is true (Yes), and it is determined that the vehicle 1 is heading outside the lane, then step S
Proceed to 18.

[0024] At step S18, whether the vehicle 1 is approaching the white line W, i.e. the distance from the white line W DR or distance DL (distance DR or DL) is a first place constant distance less than the predetermined value b It is determined whether or not there is. Specifically, when the vehicle 1 is traveling on the right side of the lane, the threshold value of the distance DR is determined. On the other hand, when the vehicle 1 is traveling on the left side of the lane, the threshold value of the distance DL is determined. . If the decision result in the step S18 is true, the distance DR or DL is a predetermined value b
If it is determined that it is less than the above, the process proceeds to step S22.

In step S22, when the direction instruction switch 6 is operated, the direction instruction information is input in step S10, and the direction instruction information has direction instruction information (ON).
Is determined. That is, here, it is determined whether or not the approach of the vehicle 1 to the white line W is based on the driver's intention. If the determination result is false (N
In o), the direction instruction information is not input to the ECU 10,
When it is determined that there is no direction instruction information (OFF), for example, the awakening degree of the driver has decreased, and the vehicle 1 is approaching the white line W against the driver's intention. In this case, the process proceeds to step S24.

As described above, contrary to the driver's intention, the vehicle 1
When the vehicle is approaching the white line W, an alarm is issued to determine that it is necessary to warn the driver that the vehicle 1 is about to depart from the lane. Therefore, in step S24, the value 1 is set to the warning flag Fw (Fw = 1) in order to store that a warning is required. Then, the process proceeds to step S28.

The result of the determination in step S18 is false, and it is determined that the distance DR or DL is equal to or greater than the predetermined value b, and that the vehicle 1 is traveling substantially in the center of the lane and is not so close to the white line W. In this case, the process proceeds to step S26. Also, when it is determined that the result of the determination in step S22 is true and the direction instruction information is in the state of having the direction instruction information (ON), the process proceeds to step S26.

As described above, when the vehicle 1 is not approaching the white line W, or when the direction instruction information is in a state where the direction instruction information is present (ON), the awakening degree of the driver decreases. No, it can be determined that the vehicle 1 is running normally,
In this case, it can be determined that there is no need to issue an alarm. Therefore, in this step S26, the value 0 is set to the warning flag Fw (Fw = 0), and it is stored that no warning is required.

When the result of the determination in step S16 is false and the vehicle 1 is separated from the white line W, for example, the vehicle 1 approaching the white line W may run again toward the center of the lane. In such a case, or when the vehicle 1 travels in a lane next to the white line W while leaving the white line W, the process proceeds to step S20. This step S2
At 0, the same threshold value determination as in step S18 is performed. That is, as described above, when the determination result of step S20 is true, the process proceeds to step S22, and the alarm flag Fw is set to the value 1 according to the determination result of step S22.
(Step S24) or value 0 (Step S26). On the other hand, if the determination result in step S20 is false, the process proceeds to step S26, and the warning flag Fw is set to a value of 0.

However, in the determination in step S20, unlike the case in step S18, the distance DR or
Determination threshold value of DL is a predetermined value a which is the second place constant distance. The predetermined value a is smaller than the predetermined value b (a <b). Referring to FIG. 5, the distance DR or
The relationship between DL and the warning flag Fw is shown. Hereinafter, the relationship between the predetermined value a and the predetermined value b will be mainly described with reference to FIG.

In FIG. 5, a point where the distance DR or DL is 0 indicates the position of the white line W. Therefore, as is apparent from FIG. 5, when the vehicle 1 approaches the white line W from near the center of the lane, the warning flag Fw is set to 1 when the distance DR or DL becomes equal to or less than the predetermined value b. If the vehicle 1 moves away from the white line W toward the center of the lane while the warning flag Fw is set to the value 1, the warning flag Fw is reset to the value 0 when the value becomes equal to or more than the predetermined value a. . That is, in the lane departure warning device, when the vehicle 1 approaches the white line W, an alarm is output at a position far from the white line W, and on the other hand, the vehicle 1
When the vehicle moves away from the vehicle, the warning is canceled at a position closer to the white line W. That is, hysteresis is provided between the determination threshold value of the distance DR or DL when the vehicle 1 approaches the white line W and the determination threshold value when the vehicle 1 separates from the white line W. The difference ba between the predetermined value b and the predetermined value a, that is, the hysteresis is a predetermined value (for example, ba = 40 cm).

That is, when the vehicle 1 moves away from the white line W, the driver can judge that the driver has responded to the warning and has already re-established the running posture of the vehicle 1. Cancel it early. As a result, it is possible to prevent the alarm from continuing to be issued even though the attitude of the vehicle 1 is properly restored, and the driver does not feel uncomfortable.

In step S28, in response to the fact that the value of the alarm flag Fw is set to 1 in step S24, an alarm output determination is made as to whether or not to actually output an alarm (alarm output determination unit 16). In this alarm output determination, a determination routine as shown in the flowchart of FIG. 4 is executed. Hereinafter, the determination procedure of the alarm output determination will be described based on FIG.

First, in step S40 in FIG. 4, when it is determined in step S22 that there is no direction instruction information (OFF), the direction instruction information is changed from the direction instruction information existence (ON) to the direction instruction information absence (ON). OFF) is determined. That is, it is determined whether or not this execution of the routine is the first execution immediately after the direction instruction information is present (ON) and the direction instruction information is not present (OFF).

If the result of the determination in step S40 is true and the execution of this routine this time is immediately after the change from the presence of direction indication information (ON) to the absence of direction indication information (OFF), then step S42 is executed. Proceed to. Normally, direction indication SW6
After the vehicle 1 is switched to the right or left side, when the turning of the vehicle 1 or the lane change running is completed, the operation position is automatically returned to the neutral position. However, especially when the vehicle 1 changes lanes,
In many cases, the driver manually returns the operation position of the direction instruction SW 6 to the neutral position. That is, the driver may return the direction instruction switch 6 to the neutral position even when the vehicle 1 has not yet completely changed lanes.

Therefore, in step S42, immediately after the direction instruction information is changed from the direction instruction information existence (ON) to the direction instruction information no (OFF), there is a possibility that the vehicle 1 is still changing lanes. In consideration of the high value, the alarm flag Fw set to the value 1 as described above is once reset to the value 0. Thereby, it is stored that the alarm is not required. The state in which the warning flag Fw is reset to 0 is maintained for a predetermined time ta.

The predetermined time ta is suitably set in advance based on, for example, the time normally required when the vehicle 1 changes lanes. Hereinafter, the procedure for measuring the predetermined time ta will be described.
The product of the execution period TS (for example, 100 msec) of the routine and the count value T (n → 0) of the subtraction timer (TS ·
T). Here, the initial value is when the count value T of the subtraction timer is a value n, and the product (T
S · n) coincides with the predetermined time ta.

In step S44, it is determined whether or not the count value T is 0 (T = 0), that is, in step S4.
It is determined whether or not a predetermined time ta has elapsed since the result of the determination at 0 is true and the timekeeping has ended. At the time when the clocking is started as described above, the count value T is equal to the value n.
Therefore, the determination result of step S44 is false, and in this case, the process proceeds to step S46.

In step S46, the count value T is subtracted. Here, the value 1 is subtracted each time the routine is executed once (T = T−1). When the routine is repeatedly executed, the next time the routine is executed,
The determination result of step S40 is false, and in this case, step S52 is executed next. In this step S52, it is determined whether or not the count value T is the initial value n. When the count value T is being subtracted as described above, the count value T is smaller than the initial value n. In this case, the process proceeds to step S44, and the count value T is further subtracted. Is done.

As the subtraction of the count value T proceeds, a predetermined time t
When a has elapsed, the count value T becomes zero. When the count value T becomes 0, the above-described step S44 is performed.
Is true, and in this case, the process proceeds to step S48. When the predetermined time ta has elapsed, as described above, for example, the vehicle 1 finishes changing lanes, the approaching state of the vehicle 1 to the white line W is released, and the warning is no longer issued. It is regarded. Therefore, in step S48, the value 0 is temporarily set in step S42.
Is reset to the value 1 again. Then, in step S50, the count value T is returned to the initial value n, in preparation for the next time measurement.

When the result of the determination in step S52 is true, that is, for example, after the driver operates the direction indicator SW to operate the direction indicator 4, the driver manually returns the direction indicator 4 and then returns to the predetermined position. Despite the passage of the time ta, the lane changing behavior of the vehicle 1 is slow, and the vehicle 1 is still in the white line W
This is a case where the vehicle is traveling while maintaining a state approaching (see steps S18 and S20). In this case, the execution result of step S48 is held as it is, and the alarm flag Fw remains at the value 1. Thus, step S
When the alarm output determination is made in 28, the process proceeds to step S30.

In step S30, it is determined whether or not the warning flag Fw has the value "1". If the determination result is true and the warning flag Fw is 1, the process proceeds to step S32. Here, an alarm signal is output to the speaker 8 in response to the alarm flag Fw having a value of 1. And
An alarm is preferably issued from the speaker 8. This allows
The vehicle 1 is approaching the white line W against the driver's intention,
The driver is warned by voice that the vehicle has departed from the lane or is in a danger of departure.

On the other hand, if the result of the determination in step S30 is false, or if the above-described step S26 has been executed and the warning flag Fw has a value of 0, the process proceeds to step S34. In this step S34, the speaker 8
Is stopped. Therefore, in this case, no alarm is issued from the speaker 8.
As described in detail above, in the lane departure warning device of the present invention, the white line W
The distance DR or the distance DL between the vehicle and the vehicle 1 is a predetermined value (first predetermined
When the vehicle 1 approaches the white line W until the distance becomes less than ( distance ) b, it is determined that the vehicle 1 deviates from the lane or is likely to deviate, and an alarm is issued (steps S18 and S24 in FIG. 3). , S32), and thereafter, when the driver moves away from the white line W in response to the warning, the distance DR or the distance DL becomes equal to or more than a predetermined value (second predetermined distance ) a smaller than the predetermined value b. When a warning is issued, the issuance of an alarm is stopped (steps S20 and S2 in FIG. 3).
6, S34). Therefore, even though the attitude of the vehicle 1 that has tended to deviate has been restored to a favorable running state, it is prevented that the alarm is meaninglessly continued to be issued, and the driver does not feel uncomfortable.

Further, in the lane departure warning device, the driver operates the direction instruction switch 6 and the direction instruction information is transmitted to the ECU 10.
When it is being supplied to the company, it will not be warned unnecessarily. Then, as described above, even when the direction instruction SW6 is returned to the neutral position when the distance DR or the distance DL is less than the predetermined value b or less than the predetermined value a, the same is continued for the predetermined time ta. No alarm is issued (see FIG. 4). Therefore, even if the driver quickly returns the direction instruction switch 6 to the neutral position while the vehicle 1 is changing lanes, for example, an alarm is issued until it is determined that the lane change is completed. The driver does not feel uncomfortable.

On the other hand, even after the lapse of the predetermined time ta, the distance DR
Alternatively, if the distance DL is less than the predetermined value b or less than the predetermined value a, and the vehicle 1 still has a tendency to deviate, an alarm is preferably issued (see steps S48 and S52 in FIG. 4). Therefore, even if the driver's awakening degree is sufficiently high and the vehicle 1 is running normally, the vehicle 1 further keeps closer to the white line W after the direction instruction SW 6 is returned to the neutral position. When the vehicle continues to travel, the driver is warned to travel toward the center of the lane. Thereby, in the lane departure warning device, the direction indication SW6
Even after the vehicle is returned to the neutral position, it is possible to satisfactorily issue a warning to the driver to keep the traveling position of the vehicle closer to the center of the lane, and the traveling safety of the vehicle 1 is sufficiently ensured. You.

In the above embodiment, the predetermined value (first predetermined distance ) b and the predetermined value (second predetermined distance ) a, which are the thresholds for determining the distance DR or the distance DL, are described as fixed values. Instead, for example, the predetermined value b and the predetermined value a may be changed according to vehicle speed information from a vehicle speed sensor (not shown) as vehicle speed detection means mounted on the vehicle 1. At this time, the difference ba, which is the hysteresis, may remain at the above-mentioned predetermined value (for example, 40 cm),
You may make it change according to the said vehicle speed information. Thereby, it is possible to realize a lane departure warning device that does not cause a sense of discomfort.

[0047]

As described above in detail, according to the lane departure warning device of the first aspect of the present invention, the traveling lane recognizing means mounted on the vehicle and recognizing the traveling lane ahead of the vehicle, and the traveling lane Traveling position recognition means for recognizing the traveling position of the vehicle in the traveling lane based on the lane information from the recognition means;
Based on the lane information and the travel position, when the lane departure determination means determines the tendency of the vehicle to depart from within the travel lane, and when the lane departure determination means determines that the vehicle is deviating,
Warning means for outputting a warning, wherein the lane departure determination means determines the tendency of departure based on the distance from the lane side edge of the vehicle.
When the vehicle is approaching the lane edge
Has a first predetermined distance not corresponding to the first determination threshold.
If the vehicle is full, it is determined that the vehicle is deviating.
When the vehicle is separated from the lane side edge after
A second predetermined distance smaller than the first predetermined distance corresponding to the determination threshold
If it is less than the separation, it is determined that the vehicle is deviating.
When the vehicle is approaching the lane edge, the vehicle and the traveling lane edge
Is determined to be a departure tendency when the distance to the vehicle is less than the first predetermined distance.
On the other hand, after the vehicle has once deviated,
When the vehicle is separated from the vehicle,
If the distance is less than a second predetermined distance that is smaller than the first predetermined distance
In this case, it can be determined that there is a deviation tendency. In other words, the vehicle tends to deviate
After it is determined that there is a vehicle and an alarm is output, the vehicle
When approaching the side edge, the vehicle approaches the side edge of the traffic lane
Release judgment of tendency to deviate earlier than when
The alarm can be suitably stopped . Therefore, it is possible to minimize the period during which the alarm is continuously output and to prevent the driver from feeling uncomfortable.

[0048]

In addition, according to the lane departure warning system of claim 2, further comprising a lane change signal outputting means for outputting a traveling lane change signal based on the intention of the vehicle driver, the warning means, the lane change signal output When the driving lane change signal based on the driver's intention is output by the means, the output of the warning is stopped regardless of the deviation tendency information of the vehicle from the driving lane by the lane departure determination means. When a driving lane change signal based on the driving lane is output and it is determined that the degree of awakening of the driver is high, even if the vehicle is approaching the driving lane side edge, it is possible to prevent the warning from being output unnecessarily. Therefore, the timing at which the warning is output can be further minimized so that the driver does not feel uncomfortable.

According to the lane departure warning device of the third aspect , the vehicle further comprises a vehicle speed detecting means for detecting a vehicle speed.
The second predetermined distance and the second predetermined distance are set according to the vehicle speed. Therefore, by setting the first and second predetermined distances according to the vehicle speed, more fine lane departure determination can be performed. For example, in a case where the vehicle speed is high, if the first predetermined distance when the vehicle is heading for the departure tendency is set to a value at which the departure tendency is determined at an early timing, the driver will not feel uncomfortable. However, it is possible to more reliably avoid departure from the lane of the vehicle.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a lane departure warning device of the present invention mounted on a vehicle.

FIG. 2 is a block diagram illustrating a configuration of a lane departure warning device.

FIG. 3 is a flowchart illustrating a lane departure warning processing routine;

FIG. 4 is a flowchart showing a processing routine for determining an alarm output in FIG. 3;

FIG. 5 is a first predetermined distance b when the vehicle approaches the white line W;
FIG. 6 is a diagram showing a relationship between the distance from a white line W and a second predetermined distance a.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 2 CCD camera (traveling lane recognition means) 4 Direction indicator 6 Direction switch (lane change signal output means) 8 Speaker (alarm means) 10 Electronic control unit (ECU) 12 White line recognition part (traveling position recognition means) 14 Lane departure determination unit (lane departure determination unit) 16 Warning output determination unit (warning unit) W White line (running lane side edge)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norio Inoue 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Tadashi Sugawara 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Misuzu Yamamoto 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) References JP-A-6-171392 (JP, A) JP flat 7-105499 (JP, a) JP flat 8-16998 (JP, a) (58 ) investigated the field (Int.Cl. ^7, DB name) B60K 28/06 B60R 21/00

Claims (3)

(57) [Claims] 1. A traveling lane recognizing means mounted on a vehicle for recognizing a traveling lane ahead of the vehicle, and a traveling position for recognizing a traveling position of the vehicle in the traveling lane based on lane information from the traveling lane recognition means. Recognition means; lane departure determination means for determining a tendency of the vehicle to deviate from the traveling lane based on the lane information and the travel position; and the lane departure determination means determines that the vehicle is in the departure tendency. Warning means for outputting a warning when the vehicle is traveling, the lane departure determining means detects the distance from the lane side edge of the vehicle.
Determining the departure tendency based on the vehicle
When the vehicle is approaching the lane edge, the distance
If it is less than the fixed distance, it is determined that the vehicle is in the departure tendency, and the vehicle
Departing from the lane side edge after the departure tendency
Sometimes, the distance is smaller than the first predetermined distance in the second
A lane departure warning device, wherein the lane departure warning device is determined to be in the departure tendency when the distance is less than a predetermined distance . 2. The vehicle according to claim 1, further comprising: a lane change signal output unit that outputs a travel lane change signal based on a driver's intention. The warning unit uses the lane change signal output unit to drive based on the driver's intention. when the lane change signal is output, regardless of the departure tendency information of the vehicle from the driving lane by the lane deviation determining means and to discontinue an output of the alarm, the lane of claim 1 Symbol placement Departure warning device. Wherein further comprising a vehicle speed detecting means for detecting a vehicle speed, wherein the first and second predetermined distance, lane departure of claim 1, wherein a set according to the vehicle speed Alarm device.