JP2000215396A - Vehicle travel controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make guidable or controllable the travel according to road situations by considering not only white line information but also the information on a static object existing on the roadside. SOLUTION: This vehicle travel controller recognizes a white line on the road by a white line recognizing means 21 on the basis of image information of the road in front of a self-vehicle, recognizes a static object in front of the self-vehicle by a static object recognizing means 22 on the basis of detection information of the object existing in front of the self-vehicle, recognizes a road structure in front of the self-vehicle on the basis of the relative position of the recognized road white line to the self-vehicle and the relative position of the static object to the self-vehicle by a road structure recognizing means 23, sets a control reference line by a control reference line setting means 24 on the basis of the recognition results and guides or controls the travel of the self-vehicle by a controlling means 20 on the basis of the relative position of the set control reference line to the self-vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel control device for guiding or controlling the travel of a vehicle based on the position of a travel lane with respect to the vehicle.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique of photographing a traveling lane with a video camera or the like and detecting a white line of the traveling lane from obtained image information. This technology is also used in vehicle travel control, for example, an automatic travel system that actively controls the vehicle to travel along the travel lane, or an alarm when the vehicle attempts to deviate from the travel lane. There has been proposed a vehicle travel control device such as a lane departure prevention system that guides the prevention of departure by giving a gentle torque in a departure avoiding direction to a steering wheel.

[0003] In these vehicle travel control devices, the detected white line is regarded as a boundary of the travel lane, and vehicle travel control is performed based on the position of the white line with respect to the own vehicle. For example, in the technology disclosed in Japanese Patent Application Laid-Open No. H10-31799, a video camera detects a white line and a laser radar detects a distance to a side wall of a vehicle, and usually performs steering control based on the position of the white line. However, there is disclosed a technology relating to automatic traveling control in which steering control is performed based on a distance to a side wall when a white line cannot be detected.

[0004]

However, when running control is performed based on the position of a white line, there are the following problems. For example, on a road where the white line and the road side are close to each other, such as a two-way expressway, a roadside wall may be provided immediately after the white line, but when the vehicle crosses the white line, the vehicle reaches the roadside. There is a possibility that it will end up. Therefore, in such a case, it is necessary to perform traveling control in consideration of the road side wall. That is, it is desired that the control according to the road condition can be performed in consideration of not only the white line information but also a stationary object existing on the road side.

On the other hand, in the technique disclosed in Japanese Patent Application Laid-Open No. Hei 10-31799, traveling control is performed based on the distance to the road side wall as well as the position of the white line. Based on this control, the distance to the road side wall is merely a substitute means when a white line cannot be detected. Therefore, it cannot be a solution to the above-mentioned problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and can provide guidance or control of traveling according to road conditions in consideration of not only white line information but also information of a stationary object existing on the roadside. It is an object of the present invention to provide a vehicle traveling control device.

[0007]

In order to achieve the above object, in a vehicle traveling control device according to the present invention, a road ahead of an own vehicle is imaged by an imaging means, and a road white line is recognized by a white line recognition means based on the image information. In addition to the recognition, the front object detecting means detects an object existing in front of the own vehicle, and the stationary object recognizing means recognizes a stationary object in front of the own vehicle based on the detection information.

The road ahead of the host vehicle is determined based on the relative position of the white line recognized by the white line recognition unit with respect to the own vehicle and the relative position of the stationary object with respect to the own vehicle recognized by the stationary object recognition unit. The structure is recognized, and a control reference line is set by control reference line setting means based on the recognition result. The control means guides or controls the traveling of the own vehicle based on the relative position of the control reference line set by the control reference line setting means with respect to the own vehicle.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 7 show a vehicle travel control device according to an embodiment of the present invention. Here, a case where the vehicle travel control device is configured as a lane departure prevention system will be described as an example.

The lane departure prevention system is for preventing a vehicle from deviating from a driving lane in an automobile and recognizing the position of the host vehicle with respect to the driving lane, which may cause a lane departure. In this case, a warning is issued to the driver, or a steering torque (auxiliary torque) different from the steering torque applied by the driver is applied to the steering shaft to warn the driver during steering of the lane departure through the steering wheel.

[0011] For this reason, in this vehicle traveling control device, FIG.
As shown in (1), as means for alerting the driver of lane departure, an alarm buzzer 10 is provided on the instrument panel of the vehicle 1, and a steering shaft 8 is provided with a steering actuator 8 for applying an auxiliary torque. Further, an information display device 9 for displaying the operation state of the lane departure prevention system to the driver is provided on the instrument panel.

In addition, a video camera 2 is provided on the roof of the vehicle 1 as an image pickup means for capturing an image of the front traveling lane in order to recognize the position of the vehicle with respect to the traveling lane. Is provided with a scanning laser radar (hereinafter, simply referred to as a laser radar) 3 as a front object detecting means for detecting an object existing in front. Further, a steering wheel angle sensor 4, a wheel speed sensor 5, and a yaw rate sensor 6 are provided, and these sensors 4 to 6 detect a steering wheel angle, a vehicle speed, and a yaw rate, respectively.

The video camera 2, laser radar 3 and control means 20 for processing information detected by the sensors 4 to 6 are provided.
Performs lane departure prevention control based on the detection information. Reference numeral 7 denotes a switch for turning on / off the operation of the lane departure prevention control by the control means 20, and is provided on the handle 12.

The structure of the control means 20 will be described in detail.
As shown in FIG. 2, the control unit 20 includes, as its functional elements, an image processing unit (white line recognition unit) 21, a radar signal processing unit (stationary object detection unit) 22, a lane structure recognition unit (road structure recognition unit) 23. , A traveling lane boundary determining unit (control reference line setting means) 24 and a lane departure prevention control unit 25. The lane departure prevention control unit 25 is an application for configuring the present vehicle travel control device as a lane departure prevention system. By applying another application, for example, an automatic traveling system or the like can be configured. Has also become.

First, the image processing unit 21 takes in an original image from the video camera 2 and extracts a road white line from the taken-in original image.
This is a means for recognizing the position of the white line with respect to. Various known methods can be applied to the extraction of the white line from the original image. For example, the extraction may be performed by the following method.

That is, first, a plurality of horizontal lines (scanning lines) are set at equal intervals on the image of the traveling lane taken from the video camera 2. Then, the luminance of each pixel is detected in the horizontal direction for each horizontal line, and the luminance change in the horizontal direction is detected. At this time, the luminance of the white road is very high while the luminance of the white road is very high while the luminance of the normal road surface is low. Therefore, a large change occurs in the luminance distribution on each horizontal line at the white line. Therefore, the portion having this luminance change can be recognized as the position of the white line on each horizontal line, and by connecting the positions of the white lines detected on each horizontal line from the lower horizontal line to the upper horizontal line, the white line is obtained. Can be extracted.

Next, based on information from the laser radar 3, the radar signal processing unit 22 determines the position of an object existing in front of the vehicle, in particular, a delineator (a pole of a reflector installed on the roadside) and a guardrail. This is a means for recognizing a stationary object on the roadside. Here, it is assumed that a delineator is provided along the traveling lane, and the position of the delineator is detected by the laser radar 3. Regarding the recognition of the delineator train in the radar signal processing unit 22, for example, various known methods such as the method described in JP-A-10-142336 can be applied. For example, the following method is used. You may do it.

First, the moving amount of the host vehicle 1 is calculated from the steering wheel angle, the vehicle speed, and the yaw rate detected by the steering wheel angle sensor 4, the wheel speed sensor 5, and the yaw rate sensor 6, respectively. Next, the laser radar 3 compares the position information of the front object detected during the previous scan with the position information of the front object detected during the current scan, and calculates the relative movement amount of the front object with respect to the own vehicle. . The moving amount of the vehicle and the relative moving amount of the front object are compared, and if they substantially match, the front object is recognized as a stationary object. If the shape of the object is a pole shape, this stationary object is recognized as a delineator. Then, the recognized individual delineators are sequentially linked and recognized as a delineator sequence.

Next, the lane structure recognizing unit 23 will be described. Here, based on the white line and the delineator train recognized by the image processing unit 21 and the radar signal processing unit 22, the structure of the traveling lane in front of the vehicle 1 is described. Recognition is performed. That is, as shown in FIG. 3, the lane structure recognition unit 23 takes the Y-axis forward in the traveling direction with the current position of the vehicle 1 as the origin, and the X-axis toward the right side of the vehicle 1. Has a visual coordinate system. Then, the recognition result of the white line input from the image processing unit 21,
The recognition result of the delineator sequence input from the radar signal processing unit 22 is developed on the above-described top view coordinate system. As a result, the left and right white lines 30R and 30L and the left and right delineator rows 31 with respect to the host vehicle 1 are set.
The positional relationship between R and 31L is clarified, and the entire structure of the traveling lane is recognized.

The traveling lane boundary determining section 24 determines the traveling lane boundary (control reference line) based on the recognition result of the lane structure recognizing section 23. The traveling lane boundary defines a reference line for performing the lane departure prevention control. The outside of the traveling lane boundary indicates a range where the danger during traveling is relatively high, and the inside is relatively low and the danger is relatively low. The range in which the vehicle can travel is shown. The determination of the traveling lane boundary is performed as follows.

First, the traveling lane boundary determining unit 24 determines whether
As shown in the figure, each of the white lines 30R and 30L
Boundary line W_R, W_LAnd the delineator rows 31R, 31L
Boundary D for each_R, D_LLike setting
ing. For example, the boundary line W _R, W_LAbout the white line
Consider the risk of exceeding 30R and 30L.
And the boundary D_R, D_LAbout the conflict with the delineator
It is set in consideration of the risk of collision.

Specifically, as shown in FIG. 4, the boundary line W _{R with} respect to the right white line 30R is located at a predetermined distance α _R from the right white line 30R toward the inside of the lane (negative direction of the X axis). boundary line W _L for the 30L, the left side white line 3
0L, a predetermined distance α in the lane inward direction (positive direction of the X axis)
_{Take L} position. Further, the boundary line D _R for the right delineator array 31R, the right delineators array 31R in lane inward (negative direction of the X axis) taken at the position of a predetermined distance beta _R, borderline D _L for the left delineator rows 31L is
The position is set at a predetermined distance β _L from the left side delineator row 31L in the lane inside direction (positive direction of the X axis). The predetermined distances β _R and β _{L with} respect to the delineator row are set larger than the predetermined distances α _R and α _L with respect to the white line in consideration of the risk (for example, α _R , α _L = 1 m, β _R , β _L =
1.5m). However, these distances α _R , α _L , β _R ,
β _L is not limited to a fixed value, and may be increased according to the vehicle speed, for example, as the vehicle speed increases. In addition, independent settings may be made on the left and right in consideration of whether the vehicle is traveling on the left or right.

Thus, the boundary between the white lines 30R and 30L
Field line W_R, W_LAnd the delineator rows 31R and 31L
Boundary line D_R, D_LIs set,
The boundary determination unit 24 determines these boundary lines W_R, W_L, D
_R, D_LFrom the positional relationship of the left and right traveling lane boundary X_R, X
_LDecisions are made. In other words, traveling on the right
Lane boundary X_RIs the boundary line W for the white line 30R._RAnd de
Boundary line D for liner row 31R_RIs shown in FIG.
In the top view coordinate system, the positive direction of the Y axis from the X axis
, The two boundaries X_R, D _R
In the lane inner direction (negative direction of X axis)
Is determined by connecting to
You. Similarly, the left driving lane boundary X_LTo the white line 30L
Boundary line W_LAnd boundary for delineator row 31L
Line D_LAnd X on the top view coordinate system shown in FIG.
From the on-axis to the Y-axis in the positive direction,
Border X_L, D_LLane inward direction (X axis positive
Direction) is determined by connecting the parts in
It is supposed to be.

When the traveling lane boundaries X _R and _XL are determined in this way, the information is output from the traveling lane boundary determining unit 24 to the lane departure prevention control unit 25. The lane departure prevention control unit 25 is an application for configuring the vehicle traveling control device as a lane departure prevention system as described above.
And a lane departure determination unit 27 and a controller 28.

First, the traveling position predicting section 26 is means for predicting the traveling position of the vehicle 1 after a predetermined time (for example, 0.5 to 1 second). The traveling position is predicted by calculation based on the current steering wheel angle, vehicle speed, and yaw rate detected by the steering wheel angle sensor 4, the wheel speed sensor 5, and the yaw rate sensor 6, respectively.
As shown in FIG. 5, the vehicle is represented on a top view coordinate system in which the current vehicle 1 is the origin, the Y axis is in the traveling direction, and the X axis is in the right direction.

The lane departure judging section 27 is means for judging the possibility of departure of the vehicle 1 from the traveling lane and the departure direction. Specifically, as shown in FIG. 6, the host vehicle 1 after a predetermined time predicted by the traveling position prediction unit 26.
Of the predicted travel position, the travel lane boundary determining unit 24 lane boundary X _R determined in, compared with the X _L, if the predicted position is to the right than the right lane boundary X _R is rightward it may have deviations, so as to determine that there is a possibility of deviation to the left in the case than the left lane boundary X _L on the left side. In the case shown in FIG. 6, since the predicted position is in the left side of the left travel lane boundary X _L, the lane deviation determining unit 27 will determine that the own vehicle 1 deviates to the left.

Next, the controller 28 controls the actuator 8, the information display device 9, and the alarm buzzer 10 based on the judgment of the lane departure judging section 27.
However, when the switch 7 is turned off, these controls are not performed with priority given to the driver's intention. Note that the actuator 8 may be any actuator that can apply torque to the steering shaft 11, but is configured here by installing a DC motor below a torsion bar (not shown) of the steering shaft 11 (on the power steering side). Shall be.

First, when the lane departure judging section 27 judges the possibility of departure, the controller 28 generates an alarm sound from the alarm buzzer 10. This warning sound may be a constant sound regardless of the degree of deviation, or the magnitude, height, etc. may be changed according to the degree of deviation. Further, for the information display device 9, the controller 28 displays the operation state of the lane departure prevention system on a display. That is, the display on the display is also turned on in conjunction with the switch 7, and when the lane departure prevention system is operating, the state, for example, the departure direction and the departure degree, are displayed.

Then, an actuator (DC motor) 8
In response, the controller 28
When it is determined that the vehicle has deviated to the left, a current is applied so as to apply a torque in the right turning direction (auxiliary torque). Conversely, when it is determined that the vehicle has deviated to the right, the vehicle turns left. An electric current in the opposite direction is applied so as to apply a torque in the turning direction. In addition, a slight vibration (for example,
In order to draw the driver's attention by generating (about 25 Hz), a vibration component is given to the supplied current.

[0030] The size of the assist torque actuator 8 is applied may be each other a constant value, the travel lane boundary X _R, according to the degree of deviation from X _L, for example, the degree of deviation You may set so that it may become large, so that it is large. However, although the assist torque itself provided by the actuator 8 also has the effect of correcting the behavior of the vehicle 1, the main purpose of this assist torque is to warn the driver through the steering system, and in the lane departure prevention system. The correction of the position of the vehicle that is likely to deviate from the driving lane should be performed by the driver's steering operation that recognizes that the vehicle is likely to deviate from the driving lane due to the application of the auxiliary torque. Therefore, the assist torque applied by the actuator 8 is limited to a magnitude that does not hinder the driver's steering operation, that is, a magnitude that the driver can easily overcome.

The vehicle travel control device according to one embodiment of the present invention is configured as described above.
The lane departure prevention control is performed according to the flow shown in FIG. As shown in FIG. 7, first, in the vehicle traveling control device, an image of a traveling lane in front of the own vehicle 1 is captured by the video camera 2, and left and right white lines 30 are obtained from the captured image.
R and 30L are recognized (step S100). Further, from the detection information of the laser radar 3, the delineator trains 31R and 31L in front of the host vehicle 1 are recognized (Step S).
110).

[0032] Then, the recognized white lines 30R, 30L, delineator rows 31R, borderline W _R for each 31L, W _L, D _R, sets the D _L, the lane bounded by the following formula X _R, the X _L Determine (Step S12)
0). Right boundary _{X R = min (W R,} D R) left boundary _{X L = max (W L,} D L) Further, the steering wheel angle sensor 4, the wheel speed sensor 5, steering wheel angle at the present time by the yaw rate sensor 6, vehicle speed, yaw rate Are detected, and the traveling position of the host vehicle 1 after a predetermined time (for example, 0.5 to 1 second) is predicted based on the detection information (step S130).

[0033] Then, when the running position of the vehicle 1 that is predicted is between the right boundary X _R and the left boundary X _L does not perform lane departure prevention control is regarded as traveling in a safe range, right when in the right side of the boundary X _R, or when than left boundary X _L on the left, it is determined that the possibility of lane departure (step S140), the alarm buzzer 1
From 0, an alarm sound is generated, a deviation state is displayed on the information display device 9, and an auxiliary torque in the deviation avoidance direction is applied from the actuator 8 (step S15).
0).

As described above, according to the vehicle traveling control apparatus, the traveling lane is not recognized based on only the white line information as in the related art, but the white line information from the video camera 2 and the delineator row information from the laser radar 3 are used. Are combined to recognize the traveling lane and set the traveling lane boundary, so that there is an advantage that traveling control can be performed according to road conditions.

For example, when the vehicle traveling control device is configured as a lane departure prevention system as described above, and when a delineator row exists near a white line, the traveling lane boundary is determined based on the position of the delineator row. The lane departure prevention system is activated earlier when the vehicle attempts to deviate because the vehicle is on the lane inner side as compared with the case determined based on the white line. Therefore, there is an advantage that the time required for the vehicle to reach the road side wall or the like over the white line is increased, the time for the driver to perform steering correction is increased, and the risk of departure from the lane is reduced.

This is particularly effective when the distance between the median strip and the white line is short on a two-way road, and in such a case, the risk of lane departure is high. By defining the traveling lane boundary according to the road conditions, the risk of departure from the lane can be reduced. If the white line is interrupted on the way, the traveling control based on the white line information alone may not function or become unstable. However, as in the present vehicle traveling control device, the white line information and the delineator train Controlling in combination with the information has an advantage that effective traveling control is possible even in such a case.

Further, it is needless to say that the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the gist of the present invention. For example, in the above embodiment, the vehicle travel control device of the present invention is configured as a lane departure prevention system. However, if the system performs travel control based on a fixed control reference line such as an automatic travel system, the present invention It is of course possible to apply. Also in this case, as in the above-described embodiment, advantageous effects can be obtained as compared with a conventional system in which a control reference line is determined and controlled based only on white line information.

In the above-described embodiment, the video camera 2 is used as the imaging means, but it may be a CCD camera or an infrared camera. As the forward object detecting means, a radio wave radar can be used in addition to the laser radar 3. Further, in the above embodiment, the case where the delineator is provided along the traveling lane has been described.However, when the guardrail is provided instead of the delineator, the guardrail is recognized and the traveling lane boundary is determined. become. That is, the vehicle traveling control device of the present invention recognizes a stationary object on the road side and determines the traveling lane boundary (control reference line) based on the position information of the stationary object and the white line information. It does not matter what is. Therefore, when the vehicle is stopped on the road side, the control reference line is determined based on the position of the vehicle, and a collision with the stopped vehicle can be avoided. The term “stationary object” as used herein is a concept including not only a completely stationary object but also an object moving at a low speed such as a vehicle moving slowly on a roadside zone.

Further, in the above-described embodiment, two left and right traveling lane boundaries are set as control reference lines, and traveling control is performed based on the positional relationship between the traveling lane boundaries and the host vehicle. Alternatively, it is also possible to set one control reference line based on the road structure, and to perform traveling control based on the positional relationship between the one control reference line and the host vehicle.

[0040]

As described above in detail, according to the vehicle traveling control apparatus of the present invention, traveling control is not performed based only on white line information as in the prior art, but based on white line information and stationary object information. Since the vehicle recognizes the road structure ahead of the host vehicle and sets a control reference line based on the recognized road structure to perform travel, guidance or control of travel according to road conditions becomes possible. There is an advantage.

Therefore, especially when the distance between the median strip and the white line is short on a two-way road, there is a high risk that the vehicle will deviate from the original traveling lane. According to the present invention, since guidance or control of traveling is performed based on a control reference line set based on the road structure, there is an advantage that the risk of departure from the traveling lane can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic vehicle configuration diagram to which a vehicle travel control device as one embodiment of the present invention is applied.

FIG. 2 is a functional block diagram showing a configuration of a vehicle traveling control device as one embodiment of the present invention.

FIG. 3 is an explanatory diagram for describing a lane structure recognition process according to the vehicle traveling control device as one embodiment of the present invention;

FIG. 4 is an explanatory diagram for describing a traveling lane boundary determination process according to the vehicle traveling control device as one embodiment of the present invention.

FIG. 5 is an explanatory diagram for describing a traveling position prediction process according to the vehicle traveling control device as one embodiment of the present invention.

FIG. 6 is an explanatory diagram for describing a lane departure determination process according to the vehicle travel control device as one embodiment of the present invention.

FIG. 7 is a flowchart illustrating a flow of lane departure prevention control according to the vehicle travel control device as one embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 vehicle 2 video camera (imaging means) 3 scanning laser radar (front object detecting means) 8 actuator 9 information display device 10 alarm buzzer 20 ECU (control means) 21 image processing section (white line recognition means) 22 radar signal processing section ( stationary object recognizing means) 23 lane structure recognition section (road structure recognition means) 24 lane boundary determining unit (control reference line setting means) 25 lane departure prevention control section 30R, 30L white line 31R, 31L delineators column X _R, X _L travel Lane boundary

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Ota 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 5H180 AA01 CC03 CC04 CC14 CC24 LL01 LL02 LL07 LL08 LL09 5L096 BA04 CA02 DA03 DA05 FA03 FA69 HA13 JA11 JA16 9A001 BB02 BB03 BB04 DD15 HH03 HH18 HH30 JJ77 KK37 KK56

Claims (1)

[Claims] 1. An image pickup means for picking up an image of a road ahead of a host vehicle, a front object detecting means for detecting an object present in front of the host vehicle, and a white line recognition means for recognizing a road white line based on image information of the image pickup means. A stationary object recognizing means for recognizing a stationary object ahead of the host vehicle based on the detection information of the front object detecting means; a relative position of the road white line recognized by the white line recognizing means with respect to the host vehicle; Road structure recognizing means for recognizing a road structure ahead of the own vehicle based on the relative position of the stationary object with respect to the own vehicle recognized by the recognizing means; and controlling based on the road structure recognized by the road structure recognizing means. Control reference line setting means for setting a reference line; and guiding or controlling traveling of the own vehicle based on a relative position of the control reference line set by the control reference line setting means with respect to the own vehicle. A vehicle travel control device, comprising: