JPH079927A - Lane departure alarm device - Google Patents

Abstract

PURPOSE:To accurately judge a lane position even in the case of rainy weather or the like by correcting a lane position on the basis of a correction value for enlarging the lane position outside as a wiper is operated faster than the preset operation with a signal processing means. CONSTITUTION:A lane correction value (d) under the operation condition of the wiper 6 is obtained. The wiper 6 can be switched between four stages of 'OFF', 'INT' (intermittent operation), 'LOW' (continuous low speed operation), 'HIGH' (continuous high speed operation). A CPU 45 computes coordinates of a lane area (lane position) on the basis of the lane correction value (d), and furthermore, computes a distance between the lane and the vehicle. In the case of a distance at a threshold value Th (for example, '0' m) or less and the winker signal is OFF (speed >=set value is desirable), the CPU 45 energizes an alarm 5 to generate the alarm.

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 device, and more particularly to a white line or a yellow line (hereinafter referred to as a lane) by monitoring a road surface condition in front of a vehicle by a lane sensor.
The present invention relates to a device that warns a deviation of a vehicle from the vehicle.

[0002]

2. Description of the Related Art A conventionally known lane departure warning device (for example, Japanese Patent Application No. 4-170593) is installed at a predetermined front center of a vehicle 10 as shown in FIGS. 4 (a) and 4 (b). By attaching a line camera (one-dimensional CCD camera) 1 as a lane sensor and detecting the lane (white line) WL on the road surface 20 and binarizing it, the positional relationship between the vehicle 10 and the lane WL, that is, between the two A lane departure is determined from the distance, and when it is determined that the vehicle deviates, an alarm is issued to the driver.

FIG. 5 schematically shows the structure of a lane departure warning system using such a line camera 1. In the figure, 2 is a vehicle speed sensor, 3 is a winker (direction indicator),
Reference numeral 4 is a controller that generates a lane departure warning signal, and 5 is an alarm device that receives a lane departure warning signal and issues an alarm.

Further, the controller 4 is the line camera 1
A / D converter 41 for converting the analog output of the vehicle into a digital signal, the vehicle speed signal from the vehicle speed sensor 2 and the winker 3
Circuit 42 for inputting a winker signal from the ROM, a ROM 43 storing a control program, an output circuit 44 for giving an output signal to the alarm device 5, and a CP connected to these.
U45 and a power supply circuit 4 for supplying power in the controller 4
6 and 6.

FIG. 6 shows the arrangement of the lane departure warning system shown in FIG. 5 when the components are actually attached to the vehicle 10. The line camera 1 as lane detecting means.
Is installed on the roof at the front of the vehicle 10, and the controller 4 equipped with a CPU as signal processing means is provided under the seat of the driver's seat so that output signals from the vehicle speed sensor 2 and the winker 3 are also input at the same time. ing.

The alarm device 5 includes an actuator drive circuit 51 driven by the controller 4 and a steering actuator 5 driven by the drive circuit 51.
It is composed of 2 and. The actuator 52 gives an alarm to the driver by vibrating the steering wheel 11 when an alarm is issued.

FIG. 7 shows a flow chart of a control program stored and executed in the CPU 45 of the controller 4 in the lane departure warning system shown in FIG. 5, and hereinafter, referring to this flow chart, FIG. 6
The operation of the conventional example shown in FIG.

First, the CPU 45 reads the camera signal from the line camera 1, the vehicle speed signal from the vehicle speed sensor 2 and the winker signal from the winker 3 after initialization (step S0) (step S1).

Of the signals read as described above, the camera signal on the horizontal center line CL passing through the center O, for example, as shown in FIG. However, there is only scanning in the horizontal direction), but it is determined by whether the threshold Th shown by the dotted line in FIG.

Then, the CPU 45 extracts the lane WL on the road surface (lane width on the center line CL in this example) from the binarized camera signal as shown in FIG. 8 (a) and calculates its coordinates. (S3), and the distance between the lane and the vehicle is calculated (S4).

In order to determine whether or not the vehicle deviates from the lane based on the positional relationship between the vehicle and the lane thus obtained, the distance between the lane and the vehicle is a threshold Th (for example, "0" m).
It is determined whether or not it is below (at step S5), and if it is at least the threshold value Th, an alarm output is not generated (at step S9), and the process returns to step S1. .

That is, even if the vehicle is approaching the lane WL, it is not necessary to issue an alarm when the lane is changed. Therefore, it is judged in step S6 whether or not the winker signal is generated, and the winker signal is detected. When it is given from the turn signal 3 (when ON), the alarm output is not generated (S9) and the process returns to step S1.
When the winker signal is not generated, it is further determined whether or not the vehicle speed exceeds the set value (for example, 60 km / h) (at step S7).

Whether or not the vehicle speed exceeds the set value is determined in step S7 because when the vehicle speed <the set value, the vehicle is traveling on a low speed road or the like in which the lane is not clear. This is to exclude such cases. However, this step S7 is not an essential step.

Therefore, if the vehicle speed is less than the set value, the process returns to step S1, but if the vehicle speed exceeds the set value, it is determined that the vehicle is traveling on a low speed road where the lane is clear. The alarm device 5 is driven to issue a departure warning (at step S8).

[0015]

Generally, the paint (white / yellow) portion of the lane detected by the conventional lane departure warning system as described above is about 7.degree. From the inner edge of the lane as shown in FIG. The position outside 5 cm is used as the coordinates of the lane area (step S8 in FIG. 7: lane position).

This is based on the fact that the basic line width of the lane is 15 cm, and also in the case of wide paint such as lanes and lanes, the inside paint position is 15 cm as shown in the figure. This is because they are similar.

When the lane position is detected from the painted portion as described above, the lane can be normally judged as shown in FIG. 10 (a) under normal weather conditions. If it is possible, due to the refraction / reflection phenomenon of light, as shown in (b) of the figure, it appears to be bulging more apparently than the paint part of the actual lane WL. If the position is determined to be the lane position, the lane is determined to be narrower than it actually is.

As a result, the lane-to-vehicle distance calculated in step S4 in FIG. 7 becomes smaller, and the set value Th is set although the vehicle does not actually depart from the lane.
There is a problem in that the lane departure warning is issued when the following is determined.

Accordingly, the present invention extracts the lane position on the road surface by binarizing the image signal obtained from the lane sensor for photographing the front of the vehicle by the signal processing means, and the distance between the lane position and the vehicle. In the lane departure warning device that performs warning processing to activate the alarm device when the blinker is not operated when is below a certain value, the purpose is to enable accurate lane position determination even in rainy weather. To do.

[0020]

In order to achieve the above object, in the lane departure warning system according to the present invention, the signal processing means determines the lane position of the vehicle as the wiper operating state stored in advance becomes faster. The feature is that the lane position is corrected by a correction value for expanding outward.

In the present invention, the condition for the alarm processing may include the time when the vehicle speed from the vehicle speed sensor exceeds the set value.

[0022]

In the operation of the lane departure warning apparatus according to the present invention, first, the signal processing means is obtained from the lane sensor as shown in FIG.
The image signal (solid line) of the lane as shown in (2) is binarized by the threshold Th to detect the coordinates (lane position) of the lane area.

At this time, the signal processing means stores the correction value of the lane position according to the operating state of the wiper in advance in order to correct the lane position in response to rainy weather.

Therefore, the operation of the wiper becomes faster as the amount of rainfall increases in the case of rain, and the lane position is expanded to the outside of the vehicle in consideration of the bulging of the edge portion of the lane correspondingly. To make a correction.

Then, based on the lane position thus obtained, the signal processing means obtains the distance between the lane and the vehicle, and when the distance becomes a certain value or less, the winker is not operated (preferably the vehicle speed is Activate the alarm if it exceeds the set value.

Therefore, it is possible to eliminate a false alarm in rainy weather.

[0027]

FIG. 1 shows an embodiment of a lane departure warning system according to the present invention. The difference between this embodiment and the conventional example shown in FIG. 5 is that the wiper signal of the wiper 6 is passed through an input circuit 42. It is taken in by the controller 4.

A flow chart of a control program stored and executed in the CPU 45 as the signal processing means in this embodiment is shown in FIG.

The operation of the embodiment of the lane departure warning system according to the present invention will be described below with reference to the flow chart of FIG.

The difference between this flowchart and the flowchart shown in FIG. 7 is that in FIG. 2, steps S2 and S of FIG.
The point is that step S10 is provided between the first and second steps.

That is, after executing steps S0 to S2,
In step S10, the lane correction value d depending on the operating state of the wiper 6 is obtained.

A memory map for obtaining this lane correction value d is shown in FIG. 3, and this memory map is obtained by experiments or the like and stored in the ROM 43 of FIG. 1 as data.

According to the map example of FIG. 3, the wiper 6 is
"OFF", "INT" (intermittent operation), "LO"
If it is possible to switch in four stages of "W" (continuous low speed operation) and "HIGH" (continuous high speed operation), in the case of, the normal lane position is 7.5 cm from the detection edge,
In the case of, the amount of rain is small and the amount of water is small, so it is 0.8 cm. In this case, the amount of rainfall is, for example, a downpour, and there are many pools of water, so 12.0 cm is set as the lane position.

Using the lane correction value d thus obtained, the CPU 45 calculates the coordinates (lane position) of the lane area (step S3), further calculates the lane-vehicle distance (step S4), and step S5. When this distance is equal to or less than the threshold Th (for example, “0” m) and the winker signal is OFF (and preferably when vehicle speed ≧ setting value), the alarm device 5 is activated.
Is activated to give an alarm (step S5).
~ S8).

[0035]

As described above, according to the lane departure warning system of the present invention, the signal processing means expands the lane position to the outside of the vehicle as the operation state of the wiper stored in advance becomes faster. Since the lane position is corrected by the correction value for, the lane position can be determined more accurately regardless of the weather or the road surface condition (puddle, etc.), and the lane can be determined closer to the vehicle than it actually is. It is possible to prevent a false alarm from being generated due to the accident.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a lane departure warning system according to the present invention.

FIG. 2 is a flow chart diagram of a control program stored and executed in a signal processing means (controller) used in the lane departure warning apparatus according to the present invention.

FIG. 3 is a lane position correction map diagram in the lane departure warning system according to the present invention.

FIG. 4 is a diagram showing an arrangement of lane sensors in a vehicle.

FIG. 5 is a block diagram showing a configuration of a conventional example.

FIG. 6 is a schematic diagram showing a configuration when the embodiment of FIG. 5 is mounted on an actual vehicle.

FIG. 7 is a flowchart showing a processing program of a conventional example.

FIG. 8 is a waveform diagram showing a front road surface state imaged by a line camera and an image signal obtained by the line camera in a relationship between pixel coordinates and luminance.

FIG. 9 is a diagram showing a painted state of a lane.

FIG. 10 is a diagram showing a lane detection state in fine weather and in rainy weather.

[Explanation of symbols]

 1 line camera (lane sensor) 2 vehicle speed sensor 3 winker 4 signal processing means (controller) 5 alarm device 6 wiper 43 ROM 45 CPU WL lane The same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A lane position on a road surface is extracted by binarizing an image signal obtained from a lane sensor for photographing the front of the vehicle by a signal processing means, and a distance between the lane position and the vehicle is a constant value. In the lane departure warning device that performs an alarm process for activating an alarm device when the winker is not operated when the following occurs, the signal processing means changes the lane position as the wiper operating state stored in advance becomes faster. A lane departure warning device, characterized in that the lane position is corrected by a correction value for expanding to the outside of the vehicle. 2. The lane departure warning system according to claim 1, wherein a condition when the vehicle speed from the vehicle speed sensor exceeds a set value is added to the condition of the warning process.