JP2004026031A - Lane departure preventing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the sense of incongruity from being given to a driver in such construction as to grant departure preventing torque for the purpose of preventing the departure of a lane. <P>SOLUTION: This lane departure preventing device comprises a vehicle attitude specifying part 11 for detecting the attitude of a vehicle on a travel road in cooperation with a lane recognition sensor, a steering torque granting part 12 for granting a steering wheel departure preventing steering torque enough to make the vehicle attitude changed in an anti-departing direction and parallel to the travel road when the vehicle attitude specifying part 11 detects that the vehicle departs or tends to depart from the travel road, and a vehicle attitude control part 13 for controlling the vehicle attitude to be kept parallel to the travel road for a certain time when the steering torque granting part 12 grants the departure preventing steering torque to make the vehicle attitude parallel to the travel road. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lane departure prevention device that applies a steering torque for departure prevention so as to prevent a vehicle from deviating from a traveling road on which the vehicle is currently traveling.
[0002]
[Prior art]
2. Description of the Related Art There has been proposed a technology (driving assistance device) that grasps the position and attitude of a vehicle with respect to a traveling path during traveling, and performs automatic traveling control of a vehicle based on the information and assists driving of a driver.
There are technologies that support such driving, such as notifying the driver of a driving error or assisting driving in a direction to eliminate such a mistake. One such driving support device is lane departure prevention. There is a device.
[0003]
The lane departure prevention device applies a departure prevention torque (or return torque) different from the steering torque applied by the driver to warn the driver and correct the position of the vehicle. There is something. For example, a change in the relative position between the host vehicle and the traveling road is monitored by a forward monitoring camera, and when the host vehicle is about to deviate from the traveling road, the deviation preventing torque is weak enough to allow the driver to easily overcome. It is provided in the direction.
[0004]
If there is a possibility that the vehicle 1 may deviate due to such traveling control, as shown as a change in the attitude of the vehicle 1 from (A) in FIG. 9 to (B) in FIG. The attitude of the vehicle 1 is corrected in the direction indicated by the arrow A4 in (A).
In addition, in addition to such control, there are also those that apply vibration to the steering wheel, output a warning sound, and display a warning. Examples of such techniques include those disclosed in JP-A-6-274798 and JP-A-13-175999.
[0005]
[Problems to be solved by the invention]
However, in such a conventional technique, the departure prevention torque is applied until the vehicle direction becomes parallel to the lane or until the vehicle departs from the lane to some extent.
Therefore, as shown in FIG. 10 (B), when such lane departure prevention control is performed on the road 100 where the road surface cant is strong, the departure prevention torque is applied, and the vehicle 1 moves parallel to the lane. After that, since the vehicle 1 loses due to the road surface cant, the driver may feel that strong control has been applied and feel uncomfortable. That is, as shown in FIG. 10 (A), there is no problem when the road 100 has no road cant or the road cant is weak. However, if the road cant is strong, the vehicle 1 goes against the driver's intention. The driver naturally misbehaves (behavior in the direction indicated by arrow A5 in FIG. 10 (B) in FIG. 10) due to the lane departure prevention control, and feels uncomfortable.
[0006]
Accordingly, the present invention has been made in view of the above-described problem, and even when a configuration is used in which a departure prevention torque is applied for the purpose of preventing a lane departure, a lane departure that can prevent a driver from feeling uncomfortable is provided. The purpose is to provide a prevention device.
[0007]
[Means for Solving the Problems]
In order to solve the above problem, according to the present invention, when it is detected that a vehicle has deviated or is likely to deviate from a traveling path by a vehicle attitude detecting unit that detects the attitude of the vehicle with respect to the traveling path, the vehicle attitude of the vehicle is determined. Is applied to the steering wheel by the steering torque applying means so that it changes in the anti-deviation direction and becomes parallel to the traveling path. When the attitude becomes parallel to the travel path, control for maintaining the vehicle attitude parallel to the travel path is performed by the vehicle attitude control means for a certain period of time.
[0008]
That is, in the present invention, the steering torque for preventing departure is applied so that the vehicle attitude becomes parallel to the traveling road for the purpose of lane departure prevention, but when the vehicle attitude becomes parallel to the traveling road, That state is maintained for a certain period of time.
[0009]
【The invention's effect】
According to the present invention, since the control for maintaining the vehicle attitude with respect to the traveling road is performed at the timing of the end of the control for preventing the departure from traveling, that is, from the control for preventing the departure to the traveling by the driver's steering operation, During the transition to the traveling of the vehicle, the control of one step (control for maintaining the vehicle attitude with respect to the traveling road) is performed, so that the driver can know that the control for preventing the lane departure has ended by this control. Can be. Therefore, even if the vehicle exhibits the same behavior as the lane departure prevention control due to a road cant or the like after the end of the lane departure prevention control, the driver knows that the vehicle behavior is not due to the lane departure prevention control. Can be.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a configuration of a vehicle 1 to which the present invention is applied. In FIG. 1, reference numeral 10 denotes a control unit for controlling each component, reference numeral 2 denotes a steering wheel, and reference numeral 3 denotes a direction instruction. A steering detection sensor 4 for detecting a steering state of the steering wheel 2; a steering actuator 5 controlled by the control unit 10 to apply a steering torque to the steering wheel 2; Is a lane recognition sensor configured by a camera or the like so as to recognize the traveling lane, 7 is a steering device, and 8 is a vehicle speed sensor for measuring the own vehicle speed. Here, the steering device 7 is a hydraulic power steering device that assists the operating force of the steering handle 2 with hydraulic pressure.
[0011]
Next, the operation of each unit will be described while explaining the processing of the control unit 10. FIG. 2 shows a configuration of the control unit 10, and FIG. 3 shows a processing procedure of the control unit 10 realized by the configuration.
Although the control unit 10 is configured to be able to control each component, as shown in FIG. 2 as a configuration for realizing the present invention, a vehicle attitude specifying unit 11, a steering torque applying unit 12, a vehicle attitude control A section 13 is provided. With such a configuration, the vehicle has deviated from or is likely to deviate from the travel path by the vehicle attitude identification unit 11 serving as a vehicle attitude detection unit that detects the attitude of the vehicle with respect to the travel path in cooperation with the lane recognition sensor 6. When such a situation is detected, a steering torque for departure prevention (hereinafter referred to as departure prevention torque) that changes the vehicle attitude of the vehicle in the anti-departure direction and becomes parallel to the traveling path is applied. When the vehicle attitude becomes parallel to the travel path by applying the deviation preventing torque to the steering wheel 2 by the section 12, the vehicle is controlled to maintain the vehicle attitude parallel to the travel path. This is performed by the attitude control unit 13 for a certain period of time.
[0012]
That is, in the processing procedure shown in FIG. 3, the control unit 10 determines lane departure in step S1. The lane departure determination is performed based on the image information from the lane recognition sensor 6.
That is, the image of the traveling lane is input to the control unit 10 by the lane recognition sensor 6. The control unit 10 determines whether the vehicle deviates from the driving lane based on the input driving lane image. For example, information serving as a reference (for example, position information of a white line) is first obtained from the traveling lane image, and it is determined whether or not the own vehicle deviates from the traveling lane in subsequent traveling based on the reference information. Specifically, when the reference information is the position information of the white line, the position information of the white line serving as the reference is stored in the memory, and then compared with the position of the white line in the traveling lane image input thereafter. When the position of the white line is deviated, it is determined that the own vehicle deviates from the traveling lane. It is needless to say that the determination as to whether or not the vehicle deviates from the traveling lane is not limited to such a method.
[0013]
The control unit 10 performs such a lane departure determination. If the vehicle deviates from or is likely to deviate from the driving lane, the process proceeds to step S2. If the vehicle does not deviate from the driving lane, the process proceeds to step S2. To end.
In step S2, the control unit 10 performs lane departure prevention control. In the lane departure prevention control, the throttle actuator 4 is controlled so that the departure prevention torque is applied. Here, the throttle actuator 4 is configured to apply a steering torque according to the operation of the steering wheel 2 by the driver, and the control unit 10 applies the deviation preventing torque separately from the steering torque. I have.
[0014]
The departure prevention torque is given so as to oppose the steering of the steering wheel by the driver, and by operating such a departure prevention torque separately from the steering torque, as a result, the departure from the traveling lane Departure of the vehicle is prevented. It should be noted that the magnitude of the deviation preventing torque is set to a magnitude that the driver can easily overcome.
[0015]
Then, the control unit 10 determines the end of the lane departure prevention control in the following step S3 while applying such a departure prevention torque. In the determination of the end of the lane departure prevention control, the control unit 10 determines whether or not the posture of the host vehicle has been corrected. For example, the control unit 10 determines whether or not the own vehicle is in an attitude along the lane based on the traveling lane image from the lane recognition sensor 6, and when the own vehicle is in an attitude along the lane, It is determined that the posture of the own vehicle has been corrected.
[0016]
The control unit 10 makes such a lane departure prevention control end determination. If the attitude of the own vehicle is corrected, the process proceeds to step S4. If the attitude of the own vehicle is not corrected, the process from step S2 is performed. Do it again. Thereby, the control unit 10 applies the deviation preventing torque until it determines that the posture of the own vehicle has been corrected, and stops applying the deviation preventing torque when it determines that the posture of the own vehicle has been corrected. Then, the process of step S4 is started.
[0017]
In step S4, the control unit 10 acquires the lateral displacement at the end of the lane departure prevention control. For example, as shown in FIG. 4, a lateral position where a predetermined displacement amount (or interval) L between the lane 101 and a reference position (for example, a center position in the width direction) of the vehicle 1 is detected. The control unit 10 also obtains the lateral displacement at the end of the lane departure prevention control based on information from the lane recognition sensor 6.
[0018]
Then, in the following step S5, the control unit 10 performs the lateral displacement maintaining control. In the lateral displacement maintaining control, the control unit 10 performs traveling control to maintain the displacement amount L detected in step S4, that is, to maintain a predetermined position in the road width direction at the end of the lane departure prevention control.
FIG. 5 shows an example of a circuit configuration for realizing the lateral displacement maintaining control by feedback control.
[0019]
Thus, the lateral position information Y generated by the vehicle behavior, via an integrator (1 / s) 21 and the gain K _2, by feeding back to the vehicle (actuator) 10, a feedback loop of the lateral position of the vehicle 1 Make up. Here, the integrator 21 is used to reduce the influence of disturbance, but can be controlled without it. The feedback control based on the lateral position information can be performed only with the above-described configuration. However, in order to further reduce the influence of disturbance and improve the control performance, an observer (FIG. 5) configured as shown in FIG. at the monitoring circuit) 22, a vehicle behavior estimating various disturbance factors may be the result to be fed back to the vehicle 1 via a gain K _1.
[0020]
In addition to performing such lateral displacement maintenance control, in step S6, the control unit 10 determines whether the maintenance control has been completed. In the maintenance control termination determination, the control unit 10 determines whether a predetermined time has elapsed in the execution state of the lateral displacement maintenance control described above. The control unit 10 terminates the process when a predetermined time has elapsed in the execution state of the lateral displacement maintenance control, and does not elapse the predetermined time in the execution state of the lateral displacement maintenance control. In this case, the processing from step S5 is restarted.
[0021]
Further, the control unit 10 carries out a process of simultaneously monitoring the steering operation by the driver in addition to the process shown in FIG. That is, for example, the control unit 10 monitors the steering operation state in parallel with the process shown in FIG. 3 or by an interrupt process.
Accordingly, when the control unit 10 detects that the steering operation has been performed, the control unit 10 interrupts or stops the processing illustrated in FIG. 3 described above and executes control according to the detected steering operation. Here, the case where the steering operation is detected means that the direction indicator 3 is operated and the turn signal operation is turned on, the output value of the torque sensor is output, and the steering angle of the steering wheel exceeds a predetermined threshold. Or the steering angular velocity exceeds a predetermined threshold. For example, the steering angle and the steering angular velocity can be obtained based on the detection of the operation detection sensor 4. Further, it is needless to say that the detection of the steering operation is not limited to be performed based on such information.
[0022]
In the processing shown in FIG. 3, the processing in step S1 corresponds to the processing by the vehicle attitude specifying unit 11, the processing in steps S2 and S3 corresponds to the processing by the steering torque applying unit 12, and the processing in steps S4 to S4. The processing in S6 corresponds to the processing by the vehicle attitude control unit 13.
The above is the processing content of the control unit 10, and the vehicle performs the following series of operations by such processing content.
[0023]
As shown in FIG. 6A, when there is a possibility of departure from the driving lane, a deviation preventing torque is applied to the steering wheel 2 using the steering actuator 5, and as a result, the vehicle 1 moves to the lane 101. The posture is corrected in the anti-deviation direction so as to follow (the behavior in the direction indicated by arrow A1 in the figure). Then, the departure prevention torque is continuously applied, so that the attitude of the vehicle 1 becomes parallel to the lane 101 as shown in FIG.
[0024]
Then, since the lateral displacement (lateral position) is acquired and controlled so as to maintain the lateral displacement, the vehicle 1 travels along the lane 101 (the direction indicated by the arrow A2 in the figure). Behavior). After a lapse of a predetermined time, the control for maintaining the lateral displacement is also terminated, and thereafter, normal driving, for example, driving according to the steering wheel 2 by the driver is performed.
[0025]
When a steering operation is performed by the driver, such traveling control is interrupted or stopped, and the vehicle 1 travels according to the steering operation.
As described above, the vehicle finally shifts to running according to the steering wheel 2 by the driver through the lane departure prevention control and the lateral displacement maintaining control. That is, the vehicle travels by running control incorporating steps such as lateral displacement maintaining control from the end of the lane departure prevention control to the start of normal running control.
[0026]
Then, even when a departure prevention torque is applied to correct a posture on a road having a strong road surface cant by such traveling control, as shown in FIG. The vehicle 100 travels at a traveling position parallel to the lane for a predetermined time. As a result, when the vehicle travels on a road 100 where the road cant is strong, the vehicle may eventually flow due to the road cant. The vehicle travels in parallel (behaves in the direction indicated by arrow A3 in the figure).
[0027]
Therefore, the driver knows that the departure from the driving lane has been prevented, and even if the vehicle may flow on the road surface, there is one step by performing the lateral displacement maintaining control before that, It becomes possible to understand whether or not the movement of the vehicle is due to lane departure control.
Note that this effect is not limited to the case where there is a road surface cant, that is, if the vehicle exhibits the same behavior as the lane departure prevention control after the lane departure prevention control ends, the aforementioned lateral displacement A similar effect can be obtained by performing the maintenance control.
[0028]
Further, since the lateral displacement maintenance control itself is a traveling control of a normal vehicle, that is, a configuration in which the vehicle attitude specifying unit 11 of the control unit 10 detects the vehicle attitude based on the lane recognition sensor 6 such as a camera ( The configuration of the vehicle attitude detecting means) can be realized by a normal on-board configuration, so that the driver can understand whether or not the movement of the vehicle is based on the lane departure control without adding a new device. You can do it.
[0029]
Further, when a steering operation is performed by the driver, the steering operation can be performed with priority, so that a steering operation without a sense of incongruity is realized, and in such a case, the driver's movement is controlled by the lane departure control. Can be understood.
The embodiment of the invention has been described. However, the present invention is not limited to being realized as the above-described embodiment.
[0030]
That is, in the above-described embodiment, after the departure prevention torque is applied by the departure prevention control, the temporary vehicle is controlled along the lane based on the lateral position of the vehicle, but is not limited thereto. is not. For example, control such that the vehicle follows the lane may be performed based on the steering wheel angle or the vehicle yaw rate.
Further, in the above-described embodiment, a case has been described in which the turning device 7 is a hydraulic power steering device that assists the operating force of the steering handle 2 with hydraulic pressure. However, as shown in FIG. 8, the steering device 7 may be configured by an electric steering device that assists the operating force with an electric motor. In this case, a configuration corresponding to the configuration is provided, that is, for example, a sensor unit 9 configured to detect a steering angle, a torque, and the like from the operation of the steering wheel 2 is provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a control unit.
FIG. 3 is a flowchart illustrating a processing procedure of a control unit.
FIG. 4 is a diagram used for explaining lateral displacement maintaining control.
FIG. 5 is a block diagram showing a circuit configuration for realizing lateral displacement maintaining control.
FIG. 6 is a diagram used to explain the operation of the vehicle realized by the processing of the control unit.
FIG. 7 is a diagram used for describing the effect of the present invention.
FIG. 8 is a diagram showing a configuration of another embodiment.
FIG. 9 is a diagram used to explain the operation of the vehicle realized by the conventional lane departure prevention device.
FIG. 10 is a diagram used to explain a problem with the conventional lane departure prevention device.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 vehicle 2 steering wheel 3 direction indicator 4 steering detection sensor 5 steering actuator 6 lane recognition sensor 7 steering device 8 vehicle speed sensor 10 control unit 11 vehicle attitude specifying unit 12 steering torque applying unit 13 vehicle attitude control unit

Claims (3)

Vehicle attitude detecting means for detecting the attitude of the vehicle with respect to the traveling path,
If the vehicle attitude detecting means detects that the vehicle has deviated or is about to deviate from the travel path, the vehicle attitude of the vehicle changes in the anti-departure direction and is only parallel to the travel path. Steering torque applying means for applying a steering torque for prevention to the steering wheel;
When the vehicle posture becomes parallel to the traveling road due to the application of the steering torque for preventing departure by the steering torque applying means, control for maintaining the vehicle posture parallel to the traveling road is performed for a predetermined time. Vehicle attitude control means,
A lane departure prevention device comprising: The lane departure prevention device according to claim 1, wherein the vehicle attitude control means controls a steering device based on a detection result of the vehicle attitude detection means to make the vehicle attitude parallel to a traveling road. . The lane departure prevention device according to claim 1 or 2, wherein when a driver's steering operation is detected, the steering operation is preferentially performed.

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