JPH06253311A - Lane deviation warning device - Google Patents

Abstract

PURPOSE:To eliminate the need to extend vehicle speed sensors and wire a signal line and to reduce the cost by performing lane detection only when a signal processing means which receives the voltage signal from an indication lamp driving means, turning on one of speed indication lamps, received as an operation start power supply signal. CONSTITUTION:This warning device consists of a lane detecting means 1 which photographs the scene in front of a vehicle having the speed indication lamps, the speed indication lamp driving means 2 which drives the speed indication lamps, a blinker 3, a warning device 4, and a signal processing means 5 which drives the warning device 4 by receiving respective output signals from the means 1, means 2, and blinker 3. Then the signal processing means 5 converts the image signal obtained from the lane detecting means 1 into a binary signal to extract a white line on a road surface. The signal processing means 5 drives the warning device 4 to generate an alarm unless direction indicating operation by the blinker 3 is performed when the distance between the white line and vehicle becomes less than a certain value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lane departure warning system, and more particularly to a system for warning the departure of a vehicle from the lane (white line) by monitoring the road condition in front of the vehicle with a line camera or the like.

[0002]

2. Description of the Related Art FIG. 4 schematically shows the configuration of a conventionally known lane departure warning system. In this conventional example, a lane detecting means 11 such as a line sensor, a vehicle speed sensor 12, and a direction. An indicator (winker) 13, an alarm device 14 such as a buzzer, a lane detecting means 11, and a vehicle speed sensor 12
And an indicator 14 which receives an output signal from the direction indicator 13
And a CPU 15 as a signal processing means for activating the above. The CPU 15 is supplied with power from a power supply 16.

FIG. 5 is a CPU in the embodiment shown in FIG.
15 is a flowchart of a control program stored and executed in 15. The operation of the conventional example of FIG. 4 will be described below with reference to this flowchart.

First, the CPU 15 reads the camera signal from the line sensor 11, the vehicle speed signal from the vehicle speed sensor 12, and the winker signal from the direction indicator 13 (step S1).

As for the camera signal among the signals read as described above, for example, as shown in FIG. 6, a camera signal on a horizontal line passing through the center O (this is because the line camera does not scan in the vertical direction but scans in the horizontal direction). (Because there is only one), it is judged whether it exceeds a threshold value and binarized (S
2).

Then, the CPU 15 extracts the white line WL on the road surface (white line width on the center line CL in this example) from the binarized camera signal as shown in FIG. 6 and calculates the coordinates thereof (S3 in the same figure). ), And further, the distance between the white line and the vehicle is calculated (at step S4).

In order to determine whether or not the vehicle deviates from the white line based on the positional relationship between the vehicle and the white line thus obtained, it is determined whether or not the distance between the white line and the vehicle is less than or equal to the threshold Th. (S5) If it is equal to or more than the threshold value, the process returns to step S1, but if it is equal to or more than the threshold value Th, the next step is executed.

That is, even if the vehicle is approaching the white line WL, it is not necessary to issue an alarm when the lane is changed. Therefore, in step S6, it is determined whether or not a winker signal is issued, and the winker signal is given. When it is given from the direction indicator 13, the process returns to step S1, but when the winker signal is not generated, it is further determined whether or not the vehicle speed exceeds the set value (S8).

The reason why the vehicle speed exceeds the set value in step S8 is as follows.

The vehicle speed signal from the vehicle speed sensor 12 is used to distinguish an ordinary road whose lane is erroneously detected or difficult to detect from an automobile exclusive road whose lane is easily detected according to the traveling speed of the vehicle. The speed limit on general roads is generally 60 km
/ H or less, and 80-100 Km / h or less on a motorway, it is determined in this step S8 whether or not the vehicle speed is equal to or higher than a set value (approximately 60 Km / h), and if the vehicle speed is lower than the set value. Is judged to be traveling on a general road, and there is a possibility of erroneous detection in this case, so the procedure returns to step S1. The warning device 14 is driven to issue a lane departure warning (at step S7).

[0011]

In the above-mentioned conventional example, although the vehicle speed signal from the vehicle speed sensor is used only for determining whether or not an alarm output is required, it is necessary to pull in and read the signal line to the CPU. Therefore, it takes time and effort to arrange the signal line, and it is necessary to provide an input device for reading the vehicle speed, which causes a cost problem.

Further, since the output signal of the vehicle speed sensor is generally a pulse having a frequency proportional to the vehicle speed, there is a problem in that reading and conversion / determination into the vehicle speed are troublesome.

Therefore, an object of the present invention is to realize a device capable of issuing a lane departure warning of a vehicle without using a vehicle speed sensor.

[0014]

FIG. 1 shows in principle the structure of a lane departure warning system according to the present invention for achieving the above object. Reference numeral 1 denotes a speed indicator lamp (not shown). Lane detection means for photographing the front of the vehicle, 2 speed indicator light driving means for driving speed indicator lamps, 3 direction indicator, 4 alarm device, 5 lane detecting means 1 and speed indicator light driving means 2
And a signal processing means for driving the alarm device 4 in response to the respective output signals of the direction indicator 3 and, when a voltage signal from the indicator light driving means 2 for turning on one of the speed indicator lights is given, it is activated. The operation is started as a power supply signal.

[0015]

In FIG. 1, the signal processing means 5 is the lane detecting means 1
A white line on the road surface is extracted by binarizing the image signal obtained from the vehicle, and when the distance between the white line and the vehicle is below a certain position, the direction indicating operation from the direction indicator 3 is performed. If not, the signal processing means 5 drives the alarm device 4 to generate an alarm.

However, in this case, for example, without using a vehicle speed signal for determining whether the road is a general road or a road exclusively for automobiles,
When the indicator lamp driving means lights one of the speed indicator lamps equipped in a large vehicle, the voltage signal is given to the signal processing means 5 to drive at a desired speed or more, that is, for an automobile only. Only when it is detected that the vehicle is traveling on a road or the like, the signal processing means 5 is operated to perform the same alarm processing as in the conventional case.

In this way, it is possible to remove the vehicle speed sensor which is troublesome in the arrangement of the signal lines and which is disadvantageous in cost.

[0018]

FIG. 2 shows an embodiment of the lane departure warning apparatus according to the present invention shown in FIG. 1. In this embodiment, a line camera is used as the lane detecting means 1 to drive a speed indicator lamp 10. Contact point 1 of tachograph 2 as indicator light drive means
a, 1b, 1c are used. In addition, the winker switch 3 is used as a signal indicating whether or not a direction indicating operation has been performed.
, A buzzer is used as an alarm device, and a CPU is used as the signal processing means 5.

FIG. 3 shows a flow chart of a control program stored and executed in the CPU 5 shown in FIG. 2. The operation of the embodiment shown in FIG. 2 will be described below with reference to this flow chart. .

First, the contacts 1a, 1b of the tachograph 2,
1c corresponds to a mechanical contact of a speedometer (not shown), and the vehicle is 60 km / h and 40 respectively.
The contacts are closed when the vehicle travels at a speed of Km / h or 20 Km / h or more, and the corresponding lamps of the speed indicator lamp 10 are turned on when the contacts are closed.

Further, as described in the conventional example, it is necessary to operate the lane departure warning device of the present invention only when the vehicle is traveling on an automobile-only road by dividing an ordinary road from an automobile-only road. In the embodiment, only the contact point 1a for 60 Km / h, which is determined to be traveling on an automobile road, is connected to the CPU 5, and the contact point 1a is connected to the battery power source. Therefore, the vehicle is 60 km / h.
Only when the vehicle is running as described above, the CPU 5 is supplied with power and becomes operable.

FIG. 3 shows a flow chart of a control program stored and executed in the CPU 5 shown in FIG. 2, and this flow chart is executed only when the vehicle is traveling at 60 km / h or more as described above. Therefore, only step S8 shown in FIG. 5 is removed, and steps S1 to S7 other than the step S8 may be the same as those in FIG. 5, and the description thereof will be omitted here.

[0023]

As described above, according to the lane departure warning apparatus of the present invention, the signal processing means uses the voltage signal from the indicator light driving means for turning on one of the speed indicator lights as the operation start power supply signal. Lane detection only when receiving,
Since it is configured to give an alarm when the distance between the lane and the vehicle is less than a certain value and the direction operation is not performed, it is not necessary to add a vehicle speed sensor or signal line arrangements and realize cost reduction. In addition, since the speed indicator light signal is used as the device power supply, the power supply device dedicated to the signal processing means can be omitted.

[Brief description of drawings]

FIG. 1 is a block diagram showing in principle the configuration of a lane departure warning device according to the present invention.

FIG. 2 is a block diagram showing an embodiment of a lane departure warning device according to the present invention.

FIG. 3 is a flowchart of a control program stored and executed in a signal processing unit (CPU) used in the lane departure warning system according to the present invention.

FIG. 4 is a block diagram showing the configuration of a conventional example in principle.

FIG. 5 is a flowchart of a control program stored and executed in a signal processing means (CPU) in a conventional example.

FIG. 6 is a diagram showing a screen including a white line on a road surface detected by a lane detecting means.

[Explanation of symbols]

 1 Lane detecting means 2 Speed indicator light driving means 3 Direction indicator 4 Warning device 5 Signal processing means (CPU) In the drawings, the same reference numerals indicate the same or corresponding parts.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H04N 5/225 C

Claims (1)

[Claims] 1. A white line on a road surface is extracted by a signal processing unit binarizing an image signal obtained from a lane detection unit for photographing the front of a vehicle having a speed indicator light. In the lane departure warning device for activating the warning device when the direction indicating operation is not performed when the inter-vehicle distance becomes less than a certain value, the signal processing means causes the signal processing means to turn on one of the speed indicating lights. A lane departure warning device characterized in that a voltage signal from a driving means is inputted as an operation start power supply signal.