JP4282678B2 - Lane departure warning device - Google Patents

Description

  The present invention relates to a lane departure warning device that monitors a traveling lane of a vehicle and issues a warning for lane departure.

The conventional lane departure warning device is intended to avoid a situation in which it is in contact with a vehicle traveling in an adjacent lane or an oncoming vehicle, and in order to achieve the purpose, Various alarm methods that are easy to notice have been proposed.
For example, in Patent Document 1, an image of a traveling lane is recognized by a camera, and when the vehicle is about to depart from the traveling lane, an alarm sound is emitted through a speaker to make the driver notice the lane departure. Patent Document 2 proposes a method in which when a vehicle is about to deviate from the driving lane, an alarm is provided by directly vibrating the spokes of the steering wheel by a vibration actuator built in the steering wheel. ing.

Japanese Patent Laid-Open No. 6-14230 (pages 2 to 4, FIG. 1) JP-A-6-76200 (pages 3-5, FIG. 1)

  However, in these alarm devices, drivers and passengers feel annoyance due to alarms that are issued when they are not needed, and in some cases the power of the device itself is turned off, so the acceptability to the user is low There was a problem.

 The present invention has been made to solve the above-described problems, and informs the driver of a situation in which the vehicle deviates from the traveling lane, and can increase the acceptability to the user. The purpose is to obtain.

In the lane departure warning device according to the present invention, the traveling lane recognition means for recognizing the traveling lane of the own vehicle, and two lanes constituting the traveling lane based on the traveling lane of the own vehicle recognized by the traveling lane recognition means. The dividing line lateral position calculating means for calculating the lateral position ahead of the vehicle by a predetermined distance from the own vehicle, and the two lateral positions of the two dividing lines calculated by the dividing line lateral position calculating means An alarm area setting means for setting an alarm threshold value on the inside and outside of the dividing line, respectively, so that the interval between the two alarm threshold values on the inside and outside is narrower than the width of the own vehicle ; Warning output determination means for determining to issue a warning to the driver when a wheel of the own vehicle exists between the inner and outer warning thresholds by a calculation formula using the own vehicle width , and this alarm output Depending on the judgment result of the judgment means Warning means for giving a warning to the driver, the warning output judging means deviated in the process in which one wheel of the own vehicle exceeded the outside alarm threshold, departed the driving lane, and returned to the driving lane again. When the vehicle wheel exists between the two alarm threshold values on the inner side and the outer side, it is determined not to issue an alarm.

As described above, the present invention is a travel lane recognition means for recognizing the travel lane of the host vehicle, and the two lanes constituting the travel lane based on the travel lane of the host vehicle recognized by the travel lane recognition means. A dividing line horizontal position calculating means for calculating a horizontal position ahead of the separation line by a predetermined distance from the host vehicle , and two dividing lines based on the horizontal position of the two dividing lines calculated by the dividing line horizontal position calculating means. each alarm threshold inside and outside the line, the warning area setting means is between the inner and outer two alarm threshold is set to be narrower than the width of the vehicle, the own and alarm threshold Warning output determination means for determining to issue a warning to the driver when the wheel of the host vehicle exists between the inner and outer warning thresholds, and the warning output determination by the calculation formula using the vehicle width Depending on the determination result of the means to the driver Warning means for providing a warning, and the warning output judging means deviates from the traveling vehicle in the process in which one wheel of the own vehicle exceeds the outside warning threshold value and deviates from the traveling lane and returns to the traveling lane again. When there is between two alarm thresholds on the inside and outside, it is determined not to issue an alarm, so an alarm is issued in a timely manner only when the vehicle departs from the lane, and an alarm is issued when avoiding the lane departure Therefore, the driver's discomfort can be reduced.

Embodiment 1 FIG.
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a lane departure warning device according to Embodiment 1 of the present invention.
In FIG. 1, the traveling lane recognition means 10 recognizes a traveling lane by recognizing a white line that separates a lane adjacent to the traveling lane along which the host vehicle travels, and a demarcation line such as a bag. The dividing line lateral position calculating unit 11 calculates the lateral position of the dividing line ahead of a predetermined distance based on the approximate polynomial of the dividing line of the lane output from the traveling lane recognition unit 10. The warning area setting unit 14 sets two warning threshold values on the inner side and the outer side with respect to the left and right dividing lines with reference to the horizontal position of the dividing line ahead of the predetermined distance obtained from the dividing line horizontal position calculating unit 11. Provided between the left and right as warning areas. This warning area is set narrower than the width of the host vehicle. The alarm output determination means 12 determines whether or not alarm output is possible due to the presence of a wheel on the basis of two alarm threshold values (that is, an alarm area) inside and outside obtained from the alarm area setting means 14. . When the alarm output is determined by the alarm output determination means 12, the alarm means 13 is operated by incorporating a vibration actuator into the steering, applying vibration to the driver's hand, or incorporating a vibration actuator into the seat. Alarm by giving vibration to the person.

FIG. 2 is an explanatory diagram showing a traveling lane recognition means of the lane departure warning device according to Embodiment 1 of the present invention.
In FIG. 2, a camera 21 is attached near the rear mirror of a vehicle 20 having wheels 22 so as to project the front of the vehicle.

FIG. 3 is a diagram showing a vibration generator of the lane departure warning device according to Embodiment 1 of the present invention.
In FIG. 3, a vibration actuator 31 is incorporated in the steering 30 to apply vibration to the driver's hand.

FIG. 4 is a diagram showing another vibration generator of the lane departure warning device according to Embodiment 1 of the present invention.
In FIG. 4, the vibration actuator 41 is incorporated into the seat 40 and operated to give a vibration to the driver and give an alarm.

FIG. 5 is an explanatory diagram showing a method for setting a warning area of the lane departure warning device according to Embodiment 1 of the present invention.
In FIG. 5, 20 and 22 are the same as those in FIG. In FIG. 5, a dividing line 50 and an alarm area 51 are shown.

  FIG. 6 is a flowchart showing the operation of the lane departure warning device according to Embodiment 1 of the present invention.

FIG. 7 is an explanatory diagram showing changes in the state of the host vehicle from the departure from the lane of the lane departure warning device according to Embodiment 1 of the present invention until the vehicle returns.
7, 20, 22, 50 and 51 are the same as those in FIG. The vehicle traveling in the middle of the lane as shown in FIG. 7A starts to deviate from the lane as shown in FIG. 7B, departs from the lane as shown in FIG. This avoids lane departure.

FIG. 8 is an explanatory diagram showing a state in which the host vehicle of the lane departure warning device according to Embodiment 1 of the present invention moves to the adjacent lane.
In FIG. 8, 20, 22, 50 and 51 are the same as those in FIG.

Next, the operation will be described.
The traveling lane recognition means 10 in FIG. 1 recognizes a white line, a saddle, or the like that separates a lane that is attached to the traveling lane along which the host vehicle travels. Specifically, for example, as shown in FIG. 2, a road image in front of the vehicle including the traveling lane is captured using a camera 21 attached in the vicinity of the rear mirror of the vehicle 20 so as to reflect the front of the vehicle. The travel lane is recognized by image processing from the luminance distribution. Then, the recognized travel lane is approximated by a polynomial as in the following formula (1), and the shape of the travel lane is output.
Approximate expression x = Ay ² + By + C Expression (1)
Here, A, B, and C are constants. x is the horizontal position of the separator line. y is the forward distance.

Next, the horizontal position of the dividing line ahead of the predetermined distance is calculated by the dividing line horizontal position calculating means 11 based on the approximate polynomial of the lane dividing line output from the traveling lane recognition means 10. The predetermined distance is set as shown in the following formula (2) using, for example, the host vehicle speed v and the time t required to turn on / off the alarm means 13.
Predetermined distance y = v × t Expression (2)
That is, by predicting the position of the white line after t seconds when the vehicle maintains the current course, and determining the alarm ON / OFF, without being affected by the time required for ON / OFF of the alarm means 13, The alarm can be turned ON / OFF at a suitable timing. Alternatively, a preset deviation prediction time (TTLC: Time To Line)
By using (Crossing), an alarm can be given at a suitable timing without being affected by the vehicle speed.

  This alarm is generated by the alarm means 13 by, for example, incorporating a vibration actuator 31 into the steering wheel 30 as shown in FIG. 3 and applying vibration to the driver's hand, or as shown in FIG. An alarm is issued by a method in which the driver is vibrated by incorporating 41 and operating.

Further, the warning area setting unit 14 uses the following formula (3) and formula based on the horizontal position X _i (i = R, L) of the dividing line ahead of the predetermined distance obtained from the dividing line horizontal position calculating unit 11. As shown in (4), two alarm threshold values X _iN and X _iF (i = R, L) are provided on the inner and outer sides of the left and right dividing lines, respectively, and the width W of the host vehicle as shown in FIG. A narrower alarm area 51 is set.
X _iF = X _i + Z _iF (i = R, L) (3)
X _iN = X _i + Z _iN (i = R, L) (4)
Here, Z _iF is a constant for setting the alarm position outside the lane, and Z _iN is a constant for setting the alarm position inside the lane. For example, Z _iN = 0 (i = R, L), Z _iF = separation By setting the width of the line (i = R, L), the alarm area 51 can be set on the separation line 50 of the traveling lane.
Alternatively, the alarm can be turned ON / OFF at a suitable timing without being affected by the vehicle speed by changing the value in accordance with a preset departure prediction time (TTLC: Time To Line Crossing).

The alarm output determination means 12 determines whether or not alarm output is possible according to the flowchart shown in FIG. 6 based on the two alarm threshold values X _iN and X _iF (i = R, L) obtained from the alarm area setting means 14. To do.

Hereinafter, the specific processing flow of the lane departure warning device will be described with reference to the flowchart of FIG.
Note that the processing shown in FIG. 6 is performed for each of the two separation lines constituting the travel lane.

First, in step S100 of FIG. 6, the travel lane is recognized using the travel lane recognition means 10. Next, in step S101, the horizontal position X _i (i = R) of the lane dividing line ahead of a predetermined distance is calculated by the dividing line horizontal position calculating means 11 based on the approximate polynomial of the lane dividing line obtained from step S100. , L) and proceeds to step S102.

In step S102, the warning area setting unit 14 sets the warning area 51 as shown in FIG. 5 based on X _i (i = R, L) obtained from step S101, and the process proceeds to step S103.

The following is processing of the alarm output determination unit 12.
In step S103, the alarm threshold value X _iN (i = R, L) obtained from step S102 is compared with the vehicle width W,
| X _iN | ≦ W / 2 (i = R, L) (5)
If so, the process proceeds to step S104 to determine whether alarm output is possible. On the other hand, if the mathematical expression (5) is not satisfied in step S103, it is determined that the host vehicle 20 is not in the warning area 51, the process proceeds to step S111, and the warning prohibition flag is turned OFF in step S111. Here, the warning prohibition flag is set in order to mask unnecessary warnings. When the own vehicle deviates from the lane, the vehicle returns to the driving lane to avoid the deviation (from FIG. 7C). As shown in FIG. 7 (D)) and FIG. 8, when the host vehicle deviates from the lane and then moves to the adjacent lane as it is, the alarm is kept from being issued. The alarm prohibition flag ON / OFF condition will be described later.

  After step S111, the process proceeds to step S112. In step S112, the alarm unit 13 is stopped, and the process of monitoring the lane departure of the host vehicle starting from step S100 is continued.

  In step S104, whether or not alarm output is possible is determined by turning on / off the blinker switch. That is, if the winker switch is ON in step S104, it is determined that the host vehicle 20 is in the alarm area 51 due to a lane change, etc., and the process proceeds to step S111. In step S111, the alarm prohibition flag is turned OFF. At the same time, the alarm means 13 is stopped in step S112. However, if the winker switch is OFF in step S104, the process proceeds to step S105.

In step S105, it is determined whether or not the alarm threshold value X _iF (i = R, L) obtained from step S102, the host vehicle width W, and the wheel width Tw of the host vehicle satisfy the following formula (6). To do.
| X _iF | ≦ W / 2−Tw (i = R, L) (6)
When the mathematical formula (6) is satisfied, as shown in FIG. 7C, the host vehicle 20 has already deviated from the lane 50 and has further crossed the lane 50, and the process proceeds to step S113, where an alarm prohibition flag is set. Is turned on, the alarm means 13 is stopped, and the process of monitoring the lane deviation of the host vehicle starting from step S100 is continued.
On the other hand, when the mathematical formula (6) is not satisfied in step S105, the process proceeds to step S106.

  If the warning prohibition flag is OFF in step S106, it is the timing at which the host vehicle starts to depart from the lane (corresponding to FIG. 7 (B) from FIG. 7A). Activate. On the other hand, when the warning prohibition flag is ON in step S106, the timing of returning to the travel lane (corresponding to FIG. 7D) in order to avoid the departure after the own vehicle 20 departs from the lane, 8 is the timing when the host vehicle deviates from the lane and then moves to the adjacent lane as it is, and since it has already warned that it has deviated from the lane once, the step without activating the alarm means 13 Returning to S100, the process of monitoring the lane departure of the host vehicle 20 is continued.

As described above, according to the first embodiment, only when the vehicle departs from the lane, the warning means is activated to avoid the lane departure or to the wheel on the side opposite to the departure direction when moving to the adjacent lane. Since unnecessary alarms are masked, driver discomfort can be reduced.
In addition, because vibration to the driver is used as a warning means, it is possible to reduce discomfort to the passengers, and for the driver to travel on the unevenness on the lane line that has already been put to practical use. It is easy to recognize and has high acceptability.

It is a block diagram which shows the lane departure warning apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the traveling lane recognition means of the lane departure warning apparatus by Embodiment 1 of this invention. It is a figure which shows the vibration generator of the lane departure warning apparatus by Embodiment 1 of this invention. It is a figure which shows another vibration generator of the lane departure warning apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the setting method of the warning area | region of the lane departure warning apparatus by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the lane departure warning apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the state change of the own vehicle after deviating from the lane of the lane departure warning apparatus by Embodiment 1 of this invention until it returns. It is explanatory drawing which shows the state which the own vehicle of the lane departure warning apparatus by Embodiment 1 of this invention moves to an adjacent lane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Traveling lane recognition means 11 Separation line lateral position calculation means 12 Alarm output determination means 13 Alarm means 14 Alarm area setting means 20 Vehicle 21 Camera 22 Wheel 30 Steering wheel 31 Vibration actuator 40 Seat 41 Vibration actuator 50 Separator line 51 Alarm area

Claims (3)

Traveling lane recognition means for recognizing the traveling lane of the host vehicle, and based on the traveling lane of the host vehicle recognized by the traveling lane recognition means, a predetermined distance ahead of the host vehicle of the two separation lines constituting the traveling lane A dividing line horizontal position calculating means for calculating the horizontal position of each of the two dividing lines, with reference to the horizontal position of the two dividing lines calculated by the dividing line horizontal position calculating means. An alarm area setting means for setting the alarm threshold value so that the interval between the two alarm threshold values on the inner side and the outer side is narrower than the width of the host vehicle, and the alarm threshold value and the host vehicle width are used. According to the calculation formula, when the vehicle wheel exists between the inner and outer alarm thresholds, the alarm output determining means for determining to issue an alarm to the driver, and the determination of the alarm output determining means Warning to the driver according to the result A warning means for giving, and the warning output judging means, in the process in which one wheel of the own vehicle exceeds the outside warning threshold value, deviates from the driving lane, and returns to the driving lane again. A lane departure warning device characterized in that a determination is made not to issue a warning when there are two wheels between the inner and outer warning thresholds. Traveling lane recognition means for recognizing the traveling lane of the host vehicle, and based on the traveling lane of the host vehicle recognized by the traveling lane recognition means, a predetermined distance ahead of the host vehicle of the two separation lines constituting the traveling lane A dividing line horizontal position calculating means for calculating the horizontal position of each of the two dividing lines, with reference to the horizontal position of the two dividing lines calculated by the dividing line horizontal position calculating means. An alarm area setting means for setting the alarm threshold value so that the interval between the two alarm threshold values on the inner side and the outer side is narrower than the width of the host vehicle, and the alarm threshold value and the host vehicle width are used. According to the calculation formula, when the vehicle wheel exists between the inner and outer alarm thresholds, the alarm output determining means for determining to issue an alarm to the driver, and the determination of the alarm output determining means Warning to the driver according to the result Warning means for giving, and the warning output judging means is a side opposite to the departure direction of the own vehicle in a process in which the own vehicle exceeds the outside alarm threshold and departs from the driving lane to enter the adjacent driving lane. when the wheel is present between the upper Symbol inner and outer two alarm thresholds, lane departure warning system and judging not to an alarm.   3. The lane departure warning device according to claim 1, wherein the warning means warns the driver by giving vibration to the driver.

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