JP2001176000A - Out-of-lane suppressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a driver from being troubled by hardly performing out-of- lane suppressing processing even when a vehicle approaches an inside lane while a driver travels the vehicle along a curve at high speed. SOLUTION: The position of the vehicle in respect of the nearside lane, on which the vehicle is to be traveled, is detected or estimated by a traveling position detecting means 15. Besides, lateral acceleration acting on the vehicle is detected or estimated by a lateral acceleration detecting means 7. Then, the presence/absence of danger for the vehicle to get out of the nearside lane is decided from the vehicle position detected by the traveling position detecting means by an out-of-lane deciding means 16 and when an out-of-lane danger state is decided by the out-of-lane deciding means 16, out-of-lane suppressing processing is performed by an out-of-lane suppressing means 17. Especially when the lateral acceleration of the vehicle or parameter value corresponding to the lateral acceleration is higher than a prescribed value, the sensitivity of the out-of-lane decision is lowered by the out-of-lane deciding means 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lane departure suppressing device which issues an alarm to prevent a vehicle from deviating from a driving lane.

[0002]

2. Description of the Related Art In recent years, there has been developed a technology (driving assistance device) for grasping the position and attitude of a vehicle with respect to a traveling road, performing automatic traveling control of a vehicle based on the information, and assisting a driver's driving. Is being developed. In the case of automatic cruise control, it is necessary to drive a car without relying on the driver at all, and various conditions such as the development of basic facilities (infrastructure) such as roads are premised on the practical application. Become.

[0003] On the other hand, in the case of a driving assistance device, the driver drives the automobile, and the driving assistance device informs the driver of a driver's driving operation error or assists driving in a direction to eliminate the error. It is. Therefore, there are many technologies for driving assistance devices that can be realized even in the current road environment, and development of driving assistance devices with higher practicality is desired.

[0004] One of such driving guide devices is a lane departure suppression device. As a lane departure suppression device, there is a technology that issues a warning to a driver when an automobile is inadvertently deviated from a traveling lane. For example, JP-A-6-4799
Japanese Patent Application Laid-Open Publication No. H11-163873 discloses a technique in which the higher the vehicle speed, the earlier the operation timing of the lane departure suppression means, so that the driver is notified of the danger earlier during high-speed traveling.

[0005]

However, according to the technology disclosed in this publication, the vehicle often approaches the driving lane when driving at high speed at the will of the driver, and especially for a skilled driver. There is a problem that it is troublesome to advance the operation timing of the lane departure suppression means.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and makes it difficult for the lane departure suppression process to be performed even when a vehicle approaches a traveling lane while the driver is driving at a high speed curve. An object of the present invention is to provide a lane departure suppression device that can prevent a driver from feeling annoying.

[0007]

For this reason, in the lane departure suppression device of the present invention, the position of the vehicle with respect to the traveling lane in which the vehicle travels is detected or estimated by the traveling position detecting means.
The lateral acceleration detecting means detects or estimates the lateral acceleration acting on the vehicle. Then, it is determined whether there is a risk that the vehicle deviates from the traveling lane from the vehicle position detected by the traveling position detection unit by the lane departure determination unit, and the lane departure determination unit determines that the vehicle is in a lane departure danger state by the lane departure determination unit. If it is determined, lane departure suppression processing is performed. In particular, when the lane departure determination unit determines that the lateral acceleration of the vehicle or a parameter value corresponding to the lateral acceleration is equal to or greater than a predetermined value, the lane departure determination sensitivity is reduced. This reduction in sensitivity can be dealt with, for example, by changing the determination value of the lane departure determination.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a lane departure suppressing device according to an embodiment of the present invention; FIG. The lane departure suppression device of the present embodiment is for preventing the vehicle from deviating from the traveling lane in an automobile, and recognizes the position of the own vehicle with respect to the traveling lane, and there is a risk of lane departure. And a braking force control actuator provided in the vehicle applies a braking force to the wheels such that a yaw moment in a direction to prevent the lane departure acts on the vehicle, and performs a lane departure suppression process for suppressing the departure from the lane. Things.

Therefore, the present lane departure suppressing device is shown in FIG.
As shown in FIG. 1, in order to recognize the position of the host vehicle with respect to the traveling lane, a camera 1 as an image pickup means for picking up an image of a road state in front of the vehicle, image information from the camera 1 is appropriately processed, and Image information processing means 11 for recognizing left and right white line positions on a road;
And a traveling lane estimating means 12 for estimating a traveling lane (traveling lane) ahead of the vehicle based on the white line position image information.

These image information processing means 11 and travel lane estimating means 12 perform white line recognition processing and travel lane estimation processing by a method as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-85249. . In other words, in the image information processing means 11, as shown in FIG. 2A, the camera 1 provided in the vehicle 1 captures black-and-white image information in a predetermined front and rear range in front of the vehicle so that the image is equally spaced on the screen. A plurality of horizontal lines 11A are set. The capture of the black and white image information is updated every minute control cycle. Then, as shown in FIG. 2B, each horizontal line 11A
In the above, the required range on the left and right of the white line position on the previous screen is set as a white line search area (processing target area) 11B. In the first screen, the white line position on the straight road is used as previous screen data.

Then, as shown in FIG. 2C, the brightness of each horizontal line is detected in the horizontal direction from the left, and the detected value is differentiated to obtain a brightness change characteristic. As a result, for example, characteristics as shown in FIG. 2D are obtained, and the white line 51 and the guardrail have a very high luminance compared to a normal road surface, so that a large change in brightness (differential value) is obtained. Then, as shown in FIG. 2E, the peaks of the change in the brightness (differential value) appear in the order of plus and minus from the left, and the intervals between the respective peaks fall within the extent considered to be appropriate as the white line 51. Is extracted as a white line candidate, and its middle point is stored as a white line candidate point 11C. Further, of these white line candidate points 11C, the one closest to the screen center is left as the final candidate point.

Finally, as shown in FIG. 2 (f), the continuity of the white line candidate points 11C in each horizontal line data in the vertical direction is sequentially verified from the bottom of the screen. That is, if the inclination between the upper and lower ends of the white line 51 on the previous screen is calculated in advance, and the lowest point 11D is set as the white line 51, the candidate point 11C on the horizontal line 11A, which is one line above, is replaced with the previous white line 51D. It is verified that the inclination is within a predetermined range. If the candidate point 11C falls within this range, it is regarded as a white line 51, and if not, the candidate point 11C is rejected, and the coordinates obtained by interpolation from the above-mentioned inclination are regarded as the white line position.

By performing the same operation for each horizontal line, a continuous white line can be recognized. Continue this white line recognition work at the required cycle,
Each time, the recognition of the white line is updated. The traveling lane estimating means 12 converts the white line 51 on the original image recognized in each recognition cycle in this way into a planar view image, and estimates the road center line LC that can be estimated from the white line 51L at the left end of the traveling lane.
The road center line LC is estimated based on L and the road center line LCR which can be estimated from the white line 51R at the right end of the traveling lane.

Further, the present lane departure suppression device compares the traveling lane (road center line) estimated by the traveling lane estimating means 12 with the predicted traveling course of the vehicle, and after a predetermined time (for example, one second). And a lane departure determining unit 16 for determining whether or not the vehicle has deviated from the lane based on the lateral deviation state detected by the lateral deviation state detecting unit 15. ing.

Here, the lateral deviation state detected by the lateral deviation state detecting means 15 is, specifically, a distance (lateral deviation amount) e of the vehicle traveling position from the center of the traveling lane, and a traveling prediction course for the traveling lane. Angle to be made (Yaw angle deviation amount) θ
The lateral displacement amount calculating means 15A and the yaw angle displacement amount calculating means 1 are functional elements of the lateral displacement state detecting means 15, respectively.
5B. Note that the lateral displacement state detecting means 15 predicts a predicted traveling course of the vehicle based on the steering angle, the yaw rate, and the vehicle speed detected by the steering angle sensor 2, the yaw rate sensor 3, and the vehicle speed sensor 4, respectively. The traveling lane estimating means 4 constitutes a traveling position detecting means for detecting or estimating the position of the vehicle with respect to the traveling lane in which the vehicle travels.

The lane departure determining means 16 determines whether any of the lateral deviation e and the yaw angle deviation θ exceeds the respective determination values (lane deviation determination values) Ke and Kθ, or both of them. When the judgment values Ke and Kθ are exceeded,
It is determined that the vehicle deviates from the lane, and a controller 1 described later
7, a lane departure signal (also indicating the lane departure direction) is output. The lane departure determining unit 16 is configured to determine whether there is a risk of the vehicle 1 deviating from the traveling lane based on the vehicle position detected by the traveling position detecting unit.

In the present embodiment, the lane departure determining means 16 determines each of the determination values Ke and Kθ for determining whether the vehicle may deviate from the lane by using the monotonousness of the driving of the driver or the monotonousness of the road. And so on based on the monotonicity of the running state of the vehicle indicating the above. The lane departure determining unit 16 determines that the monotonicity set by the monotonicity setting unit 13 is monotonicity indicating that the running state of the vehicle is monotonic (here, monotonicity is 1). The determination values Ke and Kθ are set by shifting to a side where lane departure determination is quicker than when the traveling state of the vehicle is not monotonic (here, monotonicity is set to 0). . Thus, for example, when the vehicle is traveling in a curve at a high speed (not a monotonous traveling state), the determination values Ke and Kθ of the lane departure determination are set on the side that reduces the sensitivity of the lane departure determination. Will be done.

For example, the lane departure judging means 16 has a monotonicity
Determination value Ke of lateral displacement amount e in case of 1 ₁In the case of monotonicity 0
Determination value Ke of the lateral displacement amount e in the case₀During the driving lane compared to
The side near the center (road center line) (for example, about 10 cm
Side) (see FIG. 5). Note that these determination values K
e₁, Ke₀Is set as a value corresponding to the lateral displacement amount e.
You. Also, the determination value Ke₁Is the determination value Ke₀More than running race
Is set to a small value so that the distance from the center of the
(Ke₁<Ke₀).

The lane departure judging means 16 has a monotonic degree 1
The determination value Kθ1 of the yaw angle deviation amount θ in the case of ( ₁₎ is smaller than the determination value Kθ0 of the yaw angle deviation amount θ in the case of monotonicity _0, and the angle formed by the traveling prediction course with respect to the traveling lane becomes smaller. Set to. Note that these determination values Kθ ₁ and Kθ ₀ are set as values corresponding to the yaw angle deviation amount θ. The determination value K [theta ₁ is at an angle to the running prediction course with respect to the traveling lane is set to a small value so as to be smaller than the determination value _{Kθ 0 (Kθ 1 <Kθ 0} ).

For this reason, the lane departure suppressing device is provided with a monotonicity setting means 13, and the monotonicity set by the monotonicity setting means 13 is sent to the lane departure determining means 16. I have. Here, monotonicity setting means 1
3 is a lateral G detecting lateral acceleration (lateral G) acting on the vehicle.
Sensor (lateral acceleration sensor, lateral acceleration detecting means) 7 and longitudinal G sensor (longitudinal acceleration sensor, longitudinal G calculating means) 14
Based on the information from, a monotonicity (here, monotonicity 1 or monotonicity 2) of the running state of the vehicle such as a monotonicity of the driving of the driver or a monotonousity of the road is set. That is, as described later, the monotonicity setting unit 13 determines whether or not the lane departure is determined when the front and rear G is equal to or more than the first predetermined value K1 and the lateral G is equal to or more than the second predetermined value (predetermined value) K2. The monotonicity (here, monotonicity 0) is set so as to lower the sensitivity. This is to reduce the lane departure determination sensitivity when the vehicle is not in a monotonous traveling state such as traveling on a curve at a high speed.

Here, the front and rear G sensor 14 calculates (estimates) the front and rear G by differentiating the vehicle speed detected by the vehicle speed sensor 4. Here, the horizontal G
(Lateral acceleration) is detected by the lateral G sensor 7, but the turning radius r calculated based on the steering angle detected by the steering angle sensor 2 or the yaw rate detected by the yaw rate sensor 3 and the vehicle speed sensor 4 can be estimated from the detected vehicle speed V (lateral G = V
² / r). Therefore, the steering angle, the yaw rate, and the vehicle speed V may be set as parameter values corresponding to the lateral acceleration, and the sensitivity of the lane departure determination may be reduced when it is detected that these parameter values are equal to or greater than a predetermined value. good.

The monotonicity setting processing by the monotonicity setting means 13 is performed according to the procedure shown in the flowchart of FIG. That is, first, in step S10, the front and rear G sensor 14
It is determined whether or not the G (absolute value) before and after is smaller than a first predetermined value K1 (for example, set to about 0.1 G (about 1.0 m / s ² )). Is determined to be smaller than a second predetermined value K2 (for example, set to about 0.1 G (about 1.0 m / s ² )). As a result of this determination, when it is determined that the front-rear G from the front-rear G sensor 14 is smaller than the first predetermined value K1, and when the horizontal G from the side G sensor 7 is smaller than the second predetermined value K2, Then, it is determined that the state may be a monotonous running state, and the process proceeds to step S20.

In step S20, it is determined whether or not the state in which such a monotonous running state is likely to have continued for a predetermined time T1 (for example, about 60 seconds). As a result of this determination, such a state is determined. If it is determined that the driving has continued for a predetermined time T1 (for example, about 60 seconds) or more, it is determined that the vehicle is in a monotonous running state, and the process proceeds to step S30, where the degree of monotonicity is set to 1
(Monotonicity = 1), and returns. Note that the initial setting of the monotonicity is 0. As a result, the lane departure determination is performed earlier. Here, it is determined whether or not the predetermined time T1 or more has been continued so that it can be more reliably determined that the vehicle is in a monotonous running state.

In this embodiment, as will be described later, when the vehicle shifts from the monotonous running state to the non-monotonic running state, it is immediately determined that the vehicle is not in the monotonous running state, and the monotonic degree is set to zero. In order to prevent the above, the running distance of the vehicle in a state where the running state may be non-monotonous is integrated, and it is determined whether or not the integrated value is equal to or longer than a predetermined distance T2. For this reason, when the monotonous degree is set to 1 in a monotonous running state, the integrated value of the traveling distance is cleared (0 m).

On the other hand, in step S20, a state in which there is a possibility of a monotonous running state is determined for a predetermined time T1 (for example, about 60
If it is determined that the running state has not continued for more than about (seconds), it is determined that the vehicle is not in a monotonous running state, and the routine returns with the initial setting (monotonic degree = 0). As a result, the state in which the lane departure determination is performed late is maintained. By the way, in step S10, whether the front-rear G from the front-rear G sensor 14 is equal to or more than the first predetermined value K1, or
Is greater than or equal to a second predetermined value K2, or the longitudinal G from the longitudinal G sensor 14 is greater than or equal to a first predetermined value K1, and the lateral G from the lateral G sensor 7 is greater than or equal to a second predetermined value. If it is determined that K2 is equal to or greater than K2, it is a state in which the vehicle may be in a non-monotonous traveling state. Therefore, the process proceeds to step S40, and the traveling distance of the vehicle in such a state is integrated, and the integrated value is a predetermined value. It is determined whether or not the distance has exceeded the distance T2 (for example, 150 m).

As described above, the reason for making the determination by confirming that the vehicle has traveled a predetermined distance in the predetermined state is that the vehicle is in a monotonous traveling state immediately before the determination, and that the monotonicity is set to 1 At (monotonic degree = 1), it is immediately determined that the vehicle is in a non-monotonic running state, and a hysteresis is provided so that the monotonicity is not set to zero. Further, by making a determination using the predetermined distance T2 in this manner, it is determined that the higher the vehicle speed is, the faster the vehicle is not in a monotonous running state, and the monotonic degree is 0.
Will be set to Here, the predetermined distance T2
Although the determination is made using, the determination may be made based on whether or not a state in which a non-monotonous running state is likely to have continued for a predetermined time or more.

If the result of this determination is that the vehicle was in a monotonous running state immediately before, since the integrated value of the traveling distance has been cleared, the vehicle is moved to the predetermined distance T2 in a state where the vehicle may enter a non-monotonous traveling state. When it is determined that the vehicle has traveled (for example, about 150 m) or more, the process proceeds to step S50, where it is determined that the vehicle is not in a monotonous traveling state, the monotonic degree is set to 0 (monotonic degree = 0), and the routine returns. As a result, the lane departure determination is performed later. On the other hand, in step S40,
If it is determined that the vehicle has not traveled for the predetermined distance T2 (for example, about 150 m) in a state in which the vehicle may be in a non-monotonic traveling state, the routine returns with the monotonic degree remaining at 1. As a result, the state in which the lane departure determination is performed early is continued.

If the vehicle is in a non-monotonous traveling state immediately before, the integrated value of the traveling distance is equal to or longer than the predetermined distance T2. It is determined that the vehicle has traveled the distance T2 or more, and the process returns with the monotonicity kept as it is. As a result, the state where the lane departure determination is performed late is continued.

Here, the monotonicity is set based on the front and rear G and the horizontal G, but the monotonicity may be set based on only the horizontal G. The lateral G is suitable for determining whether the vehicle is in a monotonous running state because both the monotonousness of the driving of the driver and the monotonousness of the road are taken into account. Here, it is determined whether or not the monotonous traveling state is a monotonous traveling state based on whether the state that may be the monotonous traveling state has continued for the predetermined time T1 or more, and one predetermined time T1 is used as a judgment value. However, the present invention is not limited to this.
The determination may be performed stepwise using the plurality of predetermined times.

For example, one predetermined time of a plurality of predetermined times is set to about 10 seconds, and another predetermined time is set to about 4 seconds.
Set to about 0 seconds. And when the state which may become a monotonous running state ends between 0 and 10 seconds, the above-mentioned integrated value of the running distance is left as it is, and when the state ends between 10 seconds and 40 seconds, If the integrated value of the traveling distance is cleared (0 m), for example, when a curve that turns left and right is continuous (a state that may become a monotonous state does not last longer than 10 seconds). In this case, the integrated value of the running distance is added without being cleared, so that the integrated value of the running distance becomes equal to or more than the predetermined distance T2, and it is possible to determine that the vehicle is in a non-monotonic running state. When the state where there is a possibility that the traveling state may be continued (that is, when the traveling state lasts about 10 seconds to about 40 seconds), the traveling distance is cleared, so that the integrated value of the traveling distance becomes less than the predetermined distance T2. A non-monotonic run Less likely to be determined to be state.

In the present embodiment, the monotonicity is set to one of two values of 0 or 1. However, the monotonicity is set to one of three or more values. May be set. Further, it may be set so that the monotonicity continuously changes with a change of a predetermined time as a determination value for determining whether the vehicle is in a monotonous running state. For example, the monotonicity is set to 0 from a predetermined time of 0 seconds to about 40 seconds, and the monotonicity is set to linearly change from 0 to 1 from a predetermined time of about 40 seconds to about 60 seconds. After the predetermined time of about 60 seconds, the monotonicity can be set to 1.

Further, the lane departure suppression device is configured to apply a braking force to the wheels based on the lane departure determination by the lane departure determination means 16 so that the yaw moment in the direction to suppress the lane departure acts on the vehicle. A controller (control means) 17 for controlling the braking force control actuator 20 is provided. For this reason, the controller 17 functions as a lane departure suppression unit that performs a lane departure suppression process when the lane departure determination unit 16 determines that the vehicle is in a lane departure danger state. The controller 17 receives not only the lane departure determination by the lane departure determination means 16 but also on / off information from the operation SW 9.

Next, the structure of the braking force control actuator 20 in which the braking force is controlled by the controller 17 will be described. The braking force control actuator 20 according to the present lane departure suppression device is disclosed in Japanese Patent Application Laid-Open No. H8-310360. The braking force control actuator applied to the turning control system as described above is diverted, and FIG. 4 schematically shows the configuration.

As shown in FIG. 4, in the braking force control actuator 20, the driver depresses the brake pedal 25 and the master cylinder 27 through the brake booster 26.
By operating the hydraulic pressure, the front wheel brake (F brake)
21L, 21R, rear wheel brake (R brake) 22L,
22R and a hydraulic system that drives the motor 24 by valve control separately from the driver's pedal operation and adds the hydraulic pressure generated by the hydraulic pump 23 and stored in the accumulator 28. Switching is performed by opening and closing a switching valve (SW valve) 29. Also, F brakes 21L, 21R,
The hydraulic lines to the R brakes 22L, 22R include inlet valves 31L, 31R, 33L, 33R and outlet valves 32.
L, 32R, 34L, 34R are provided, and an ABS device is composed of these valves 31L, 31R to 34L, 34R and a hydraulic source such as the accumulator 28. In addition, reference numerals for brakes and valves include:
L and R are attached, but those with L are related to the left wheel.
Those with an R are for the right wheel.

During normal running, the braking force control actuator 20 opens the SW valve 29, sets the hydraulic system to the master cylinder 27 side, and applies hydraulic pressure according to the driver's operation of the pedal 25 to the F brakes 21L, 21R, and R brakes. 22
L, 22R. Meanwhile, ABS
When the actuation of the accumulator 28 is required, the SW valve 29 is closed to switch the hydraulic system to the accumulator 28 side, and the valve 30 provided downstream of the accumulator 28 is opened to reduce the pressure in the accumulator 28 to the F brake 21L,
21R and R brakes 22L and 22R. Further, the inlet valves 31L, 31
R, 33L, 33R, outlet valves 32L, 32R, 34
L and 34R are opened and closed appropriately, whereby the F brake 21
The magnitude of the hydraulic pressure applied to the L, 21R, R brakes 22L, 22R, that is, the braking force applied to the wheels is optimally controlled so that the wheels do not lock. Here, the braking force can be controlled for each wheel.

When the braking force control actuator 20 having the above-described configuration performs the braking force control for preventing the lane departure, first, the SW valve 29 is closed, and the F brakes 21L, 21R, the R brakes 22L, 22R. Is switched to the accumulator 28 side. When either the left or right front wheel pressure increasing signal is input from the controller 17, for example, when the left front wheel pressure increasing signal is input, the inlet valve 31L on the F brake 21L side is opened, the outlet valve 32L is closed, and others. , The hydraulic pressure applied to the F-brake 21L is increased, and when the left front wheel pressure reduction signal is input, the inlet valve 31L is closed and the outlet valve 32L is opened to reduce the hydraulic pressure applied to the F-brake 21L. It has become.

Similarly, when the left rear wheel pressure increase signal is inputted, the inlet valve 33L on the R brake 22L side is opened, the outlet valve 34L is closed, and all other inlet valves are closed, and the R valve 22L is closed.
The hydraulic pressure applied to the brake 22L is increased, and when the rear left wheel pressure reduction signal is input, the inlet valve 33L is closed and the outlet valve 34L is opened to reduce the hydraulic pressure applied to the R brake 22L. Similar valve control is performed on the right front wheel side and the right rear wheel side.

Reference numeral 35 denotes a cutoff valve, 36 denotes a reservoir, and 37 and 38 denote pressure sensors.
Pressure control valves (PCV) 39L, 39R are provided between the 2L, 22R and the inlet valves 32L, 32R. Further, the lane departure suppression device is provided with the operation switch (SW) 9 for selecting the operation as described above. Therefore, if the user wants to operate the apparatus, the operation SW 9 is turned on, and if the user does not want to operate the apparatus, the operation SW 9 is turned off. Further, for example, in the instrument panel (instrument panel), there is provided an alarm means 40 for emitting an alarm sound when the vehicle is about to deviate from the lane, and for alerting the driver by hearing. Note that the process of generating an alarm sound by the alarm means 40 is also considered to be a lane departure suppression process for suppressing the vehicle from deviating from the lane. The suppression means is configured.

The image information processing means 11, traveling lane estimating means 12, lateral deviation state detecting means 15, lane departure determining means 16, controller 17, and front / rear G calculating means 14
The electronic control unit (ECU) 10 includes a PU, an input / output interface, a ROM, a RAM, and the like. Since the lane departure suppression device as one embodiment of the present invention is configured as described above, the lane departure suppression process when traveling on a curved road as shown in FIG. 5 is performed as follows. .

First, the camera 1 captures an image of a scene ahead of the traveling lane in which the host vehicle 50 is traveling. Then, a white line 5 is obtained from the captured image information by the image information processing means 11.
1L, 51R, and extract the extracted white lines 51L, 51R.
The traveling lane (traveling lane center line) 52 is estimated by the traveling lane estimating means 12 based on the 51R information. On the other hand, a steering angle, a yaw rate, and a vehicle speed are detected by a steering angle sensor 2, a yaw rate sensor 3, and a vehicle speed sensor 4 provided in the vehicle.
Is estimated. Then, the lateral displacement state detecting means 15 compares the estimated traveling lane 52 with the traveling prediction course 53,
Lateral deviation calculating means 15A, yaw angle deviation calculating means 15B
To calculate the lateral shift amount e and the yaw angle shift amount θ after a predetermined time (for example, after one second).

At this time, if any one or both of the lateral deviation amount e and the yaw angle deviation amount θ exceed the respective determination values, the lane departure determination means 16 determines that the vehicle has been traveling for a predetermined time (for example, 1 After a second), it is determined that the vehicle deviates from the lane, and a lane departure signal is output to the controller 17 so as to prevent the deviation. In the present embodiment, the lane departure determination unit 16 determines each determination value Ke, Kθ for determining whether the vehicle may deviate from the lane, using a vehicle in consideration of the monotonousness of the driving of the driver, the monotony of the road, and the like. Is changed based on the monotonicity (monotonicity 1 or monotonicity 0) of the traveling state of.

That is, as shown in FIG. 5, the lane departure determining means 16 determines each determination value Ke, when the monotonicity set by the monotonicity setting means 13 is 1, as compared with the case of monotonicity 0. Kθ is set so as to be shifted to the side where the lane departure determination is earlier. As a result, the lane departure determination is delayed when the vehicle is not in a monotonous traveling state such as when traveling on a curve at a high speed.

When a lane departure signal is input from the lane departure determination unit 16, the controller 17 emits an alarm sound from the alarm unit 40 and controls the braking force control actuator 20 for braking force. In the case shown in FIG. 5, first, the braking force control actuator 20 applies a braking force to the front wheels on the opposite side of the lane departure direction, that is, the right front wheel 42 and the right rear wheel 44.

With this braking force control, when a braking force is applied to the right front wheel 42 and the right rear wheel 44 in the vehicle 50, a yaw moment is generated clockwise. The clockwise yaw moment acts on the vehicle 50 to inform the driver that the vehicle is likely to deviate from the lane and to encourage a steering operation to avoid the lane departure. Avoidance is promoted.

Therefore, according to the present lane departure suppression device, when the lateral acceleration or the parameter value corresponding to the lateral acceleration becomes a predetermined value or more, the sensitivity of the lane departure determination is reduced. Furthermore, there is an advantage that the departure suppression processing is not easily performed even when the vehicle approaches the traveling lane, and it is possible to prevent the driver from feeling annoying.

In the above-described embodiment, the traveling position detecting means detects the traveling position of the vehicle from the image taken by the camera 2. However, the present invention is not limited to this. The configuration may be such that the traveling position of the vehicle is detected by a sensor or the like, or the relative position of the vehicle to the lane is detected using D-GPS navigation.

In the above-described embodiment, the lane departure determination is performed based on the lateral deviation amount e and the yaw angle deviation amount θ of the vehicle at the traveling position. What is necessary is to reduce the lane departure determination sensitivity when the value is equal to or greater than the predetermined value.
Further, in the above-described embodiment, as the lane departure suppression processing,
Although the method is based on the braking force control and the alarm sound, the method is not limited to this. The steering actuator may generate a steering torque (steering control torque) different from the steering torque applied by the driver, or may use the vibration actuator. By causing the steering wheel vibration, the driver may be notified of danger, and the vehicle may be prevented from departing from the lane.
A method using active yaw control (AYC) or auto speed control (ASC) may be used.

[0048]

As described above in detail, according to the lane departure suppressing device of the present invention, when the lateral acceleration or the parameter value corresponding to the lateral acceleration becomes a predetermined value or more, the sensitivity of the lane departure determination is reduced. There is an advantage that the lane departure suppression processing is not easily performed even when the vehicle approaches the traveling lane while the driver is traveling on a curve at a high speed, and it is possible to prevent the driver from feeling annoying.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a lane departure suppression device as one embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a white line recognition process according to an embodiment of the present invention, and shows the processing contents in order of (a) to (f).

FIG. 3 is a flowchart illustrating a monotonicity setting process of the lane departure suppression device as one embodiment of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a braking force control actuator according to one embodiment of the present invention.

FIG. 5 is a diagram for explaining an operation of the lane departure suppression device as one embodiment of the present invention.

[Explanation of symbols]

 7 lateral G sensor (lateral acceleration sensor, lateral acceleration detecting means) 13 monotonicity setting means 14 longitudinal G sensor (longitudinal acceleration sensor) 15 lateral deviation state detecting means (running position detecting means) 16 lane departure determining means 17 controller (control means, Lane departure suppression means) 20 braking force control actuator 40 alarm means 41-44 wheels e lateral displacement θ yaw displacement

Claims (1)

[Claims] 1. A travel position detection means for detecting or estimating a position of the vehicle with respect to a travel lane on which the vehicle travels, a lateral acceleration detection means for detecting or estimating a lateral acceleration acting on the vehicle, and a travel position detection means A lane departure determining unit that determines whether there is a risk that the vehicle deviates from the traveling lane from the vehicle position detected by the lane departure; and a lane departure when the lane departure determining unit determines that the vehicle is in a lane departure dangerous state. A lane departure suppression unit that performs a suppression process, wherein the lane departure determination unit reduces the sensitivity of the lane departure determination when a lateral acceleration of the vehicle or a parameter value corresponding to the lateral acceleration is equal to or greater than a predetermined value. A lane departure suppression device, characterized in that it is configured as follows.