JP2001048036A - Lane following device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lane following device giving a feeling of security to a driver when he/she passes an obstacle out of a lane, by correcting a target line relating to even the obstacle provided out of the lane. SOLUTION: This lane following device, having an automatic steering actuator provided in a steering force transmitting system to give steering torque or steering reaction force torque and an automatic steering control means outputting a control command of making a self vehicle follow a preset target line relating to the automatic steering actuator at automatic steering time, is provided with an out-of lane obstacle detection means, passing each other mode judgement means judging whether a passing each other mode or not where an out-of lane obstacle moves from forward near to and away from the self vehicle on the basis of detection of the out-of lane obstacle, and a target line correction means performing correction deviating the target line set in a target line setting means to a direction with no out of lane obstacle when the passing each other mode is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for taking in lane information and applying a steering torque to a steering force transmission system to perform automatic steering to follow the vehicle in a forward lane, or a steering reaction torque. The present invention belongs to the technical field of a lane following device that is applied as a control device that supports driver steering so that the own vehicle follows the front lane by giving it to a force transmission system.

[0002]

2. Description of the Related Art Conventionally, a lane following device that detects a lane condition ahead of a vehicle, calculates a target line of the vehicle from this information, and performs lane following control is disclosed in, for example, Japanese Patent Laid-Open No. 5-50.
No. 937 is known.

This publication describes a technique for detecting an obstacle or a preceding vehicle in a traveling lane and changing the lane so as to avoid the preceding vehicle (an obstacle) promptly.

[0004]

However, in the above-described conventional lane-following apparatus, since the lane change is performed to avoid obstacles in the traveling lane, obstacles outside the lane are obstructed. The lane change control for avoiding the obstacle is not performed on the object, and there is a problem as described below.

[0005] When overtaking the preceding vehicle in the adjacent lane during traveling,
Or, if you pass an oncoming vehicle on a road without a median strip, or if you pass by looking at a stopped vehicle that is stopped outside the lane, there is no obstacle in the lane, but as a driver, If you do not follow the line slightly in the direction of escaping the vehicle, psychological pressure will occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to correct a target line for an obstacle outside the lane so that the obstacle can be prevented from passing the obstacle outside the lane. An object of the present invention is to provide a lane following device that gives a sense of security to a driver.

[0007]

According to the first aspect of the present invention, there is provided an automatic steering actuator provided in a steering force transmission system for supplying a steering torque or a steering reaction torque, and a lane information detection for detecting a lane state of a road ahead. Means, a target line setting means in which a target line which is a driving lane of a target vehicle is set, and a control command for causing the vehicle to follow the set target line during automatic steering is output to the automatic steering actuator. A lane following device provided with an automatic steering control means for detecting an obstacle existing outside the lane, and an out-of-lane obstacle detecting means for detecting an obstacle outside the lane. A passing mode determining means for determining whether an obstacle is a passing mode in which the obstacle approaches and leaves, and the target line setting means when determining that the vehicle is in the passing mode. The target line is set, characterized in that a target line correcting means for correcting the shift in the direction without lane outside obstacles.

According to a second aspect of the present invention, in the lane following apparatus according to the first aspect, the passing time is predicted based on the calculated relative distance and relative speed to the detected obstacle outside the lane, and the predicted passing time is predicted. A low-pass transition time setting means for setting a low-pass transition time from the start of correction to the end of correction based on the time is provided.

According to a third aspect of the present invention, in the lane following apparatus according to the second aspect, the transition time setting means i passes each time it is determined that there is an obstacle outside the lane based on the detection of the obstacle outside the lane. The present invention is characterized in that the transition time is reset.

According to a fourth aspect of the present invention, in the lane following device according to the second or third aspect, the target line correction means is configured to set the target line correction means to be more than the first passing time set by giving a passing width to the passing time. The correction to gradually add the line deviation to the target line is started before the set time, the maximum line deviation is maintained for the passing time, and the line deviation is gradually reduced after the passing time elapses, and the second set time elapses from the passing time. At this point, the line deviation is set to zero to terminate the correction.

According to a fifth aspect of the present invention, in the lane following apparatus according to any one of the first to fourth aspects, the target line correcting means increases a maximum line deviation in proportion to a relative speed to an obstacle outside the lane. Means.

According to a sixth aspect of the present invention, in the lane following apparatus according to any one of the first to fifth aspects, the lane information detecting means and the out-of-lane obstacle detecting means photograph a road ahead in the traveling direction, and an image thereof A common camera for sending a signal to the automatic steering control means is used, and the lane condition is detected and an obstacle existing outside the lane is detected by image processing in the automatic steering control means.

[0013]

According to the first aspect of the present invention, during automatic steering, the lane information detecting means detects the lane condition of the road ahead, and the target line setting means sets the target lane as the traveling lane of the target vehicle. A line is set, and in the automatic steering control means, a command for matching the own vehicle traveling line detected with the set target line, that is, a control command for causing the own vehicle to follow the target line, is transmitted to the steering force transmission system. It is output to an automatic steering actuator that gives torque or steering reaction torque.

The passing mode determining means determines whether or not the vehicle is in the passing mode in which the obstacle outside the lane approaches and moves away from the front in the own vehicle direction based on the detection of the obstacle outside the lane from the obstacle detecting means outside the lane. When the target line correction means determines that the vehicle is in the passing mode, the target line set in the target line setting means is corrected so as to be shifted in a direction free from obstacles outside the lane.

[0015] Therefore, in the case of overtaking the preceding vehicle in the adjacent lane while driving, or passing by an oncoming vehicle on a road without a median strip, or passing by while seeing a stopped vehicle stopped outside the lane, etc. It is determined that the vehicle is in the passing mode, and the target line is corrected to be shifted in the direction where there is no obstacle outside the lane, so that when the vehicle passes the obstacle outside the lane, the line expands in the direction to avoid the obstacle, and the driver It can give a sense of security.

According to the second aspect of the present invention, the passing transition time setting means predicts the passing time based on the calculated relative distance and relative speed to the detected obstacle outside the lane, and based on the predicted passing time. Thus, a passing transition time from the start of correction to the end of correction is set.

In other words, when a camera directed to the front of the vehicle is considered as an example of the obstacle detection means outside the lane, the angle of recognition of an image that can be captured by the camera is limited. Can not. Therefore, by predicting the passing time when an obstacle outside the lane can be recognized and setting the passing transition time from the start of correction to the end of correction, it is possible to reliably correct the target line for the obstacle outside the lane.

In the third aspect of the present invention, the passing transition time setting means resets the passing transition time each time it is determined that there is an obstacle outside the lane based on the detection of the obstacle outside the lane.

Therefore, by resetting the passing transition time until the very moment when the obstacle outside the lane is captured in the image, the passing transition time set at a position where the own vehicle and the obstacle outside the lane are separated can be reduced. The estimation error of the passing transition time can be reduced as compared with the case where the fixed transition value is used for the correction.

According to the present invention, in the target line correcting means, the correction for gradually adding the line deviation to the target line from the first set time before the passing time set with the passing time having a front-back width is set. Starting, the maximum line deviation is maintained for the passing time, and when the passing time elapses, the line deviation is gradually reduced, and when the second set time has elapsed from the passing time, the line deviation is made zero and the correction is completed.

Therefore, when the vehicle passes the obstacle outside the lane, the target line is slightly swollen so as to avoid the obstacle outside the lane. Also, there is no sense of incompatibility with the following vehicles.

According to the fifth aspect of the present invention, the target line correcting means increases the maximum line deviation in proportion to the relative speed with respect to the obstacle outside the lane.

Therefore, when the vehicle passes an obstacle outside the lane, it is possible to correct the target line that matches the avoidance psychology of the driver who wants to escape as the passing speed increases.

According to the sixth aspect of the present invention, a common camera is used as the lane information detecting means and the out-of-lane obstacle detecting means, which photographs the road ahead in the traveling direction and sends the image signal to the automatic steering control means. By the image processing in the automatic steering control means, detection of the lane state and detection of an obstacle existing outside the lane are performed.

Therefore, it is advantageous in terms of cost as compared with the case where separate cameras are used for the lane information detecting means and the out-of-lane obstacle detecting means, and new members are added to those provided with the lane information detecting means. , It is possible to adopt the target line correction technology for obstacles outside the lane.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Embodiment 1 is a lane following apparatus according to the first to sixth aspects of the present invention.

First, the configuration will be described.

FIG. 1 is an overall system diagram showing an automobile steering system to which the lane following device of the first embodiment is applied. In FIG. 1, reference numeral 1 denotes a steering wheel, and 2 denotes a steering shaft (corresponding to a steering force transmission system). ), 3 is a universal joint,
4 is a rack and pinion type steering gear box, 5 is a side rod, 6 is a worm wheel gear, 7
Is a motor (corresponding to an automatic steering actuator), 8 is a worm gear, 9 is an electromagnetic clutch, 10 is a steering angle sensor, 1
1 is a CCD camera (corresponding to lane information detecting means and out-of-lane obstacle detecting means), 12 is an automatic steering controller, 13
Is an automatic steering switch, and 14 is a steering torque sensor.

The steering shaft 2 includes an upper shaft 2a which rotates integrally with the steering wheel 1.
And a lower shaft 2b connected to the upper shaft 2a by a universal joint 3. The steering wheel 1 is attached to an upper end of the upper shaft 2a.
A pinion provided at the lower end of the lower shaft 2b is screwed into a side rod 5 extending in the left-right direction of the vehicle in the rack and pinion type steering gear box 4.

A worm wheel gear 6 is provided below the upper shaft 2a. A worm gear 8 screwed to the worm wheel gear 6 is provided on a motor shaft of a motor 7, and a motor steering torque is applied to the upper shaft 2a by driving the motor. . The motor 7 has a built-in electromagnetic clutch 9.

The steering angle sensor 10 is provided above the upper shaft 2a.
And sends the signal to the automatic steering controller 12. Then, the actual steering angle calculation unit of the automatic steering controller 12 calculates the actual steering angle θd using the rotation angle θ and the steering gear ratio.

The CCD camera 11 captures an image of a road ahead in the direction of travel, and converts the image signal into an image of the automatic steering controller 1.
Send to 2. Then, the image processing unit of the automatic steering controller 12 performs image processing on the front image based on the signal from the CCD camera 11, extracts and identifies the boundary line of the front lane such as a white line or a center line, and creates the own vehicle traveling state information. At the same time, obstacles outside the lane are extracted and identified, and relative distance information and relative speed information between the own vehicle and the obstacles outside the lane are created.

When the automatic steering mode is selected, the automatic steering controller 12 calculates a target steering torque Tr necessary for causing the own vehicle to follow the target line based on the own vehicle traveling state information and the set target line information. Then, automatic steering control for outputting a control command (motor current) to the motor 7 to obtain the target steering torque Tr is performed. In addition,
The steering state by the control is fed back based on the detected actual steering angle θd.

The automatic steering switch 13 is provided at a position where a driver in the vehicle compartment can operate the automatic steering switch 13, and enters an automatic steering mode when the switch is turned on.

The steering torque sensor 14 is provided above the upper shaft 2a adjacent to the steering angle sensor 10 and detects a torsion angle φ corresponding to a driver input torque from the steering wheel 1, and outputs the signal. This is sent to the automatic steering controller 12. Then, the actual steering torque calculation unit of the automatic steering controller 12 calculates the actual steering torque Td using the twist angle φ.

Next, the operation will be described.

[Automatic Steering Control Operation] FIG. 2 is a flowchart showing the flow of the automatic steering control operation performed by the automatic steering control section (corresponding to the automatic steering control means) of the automatic steering controller 12, and each step will be described below. .

At step 30, the own vehicle traveling state information from the image processing section for processing the video signal from the CCD camera 11 for photographing the road ahead in the traveling direction is read.

At step 31, the adjacent lane obstacle detection information from the image processing section for processing the video signal from the CCD camera 11 for photographing the road ahead in the traveling direction is read, and the routine proceeds to step 32.

In step 32, it is determined whether the mode is the passing mode. If NO, the process proceeds to step 33, where YE
In the case of S, the process proceeds to step 38 (corresponding to passing mode determination means).

In step 33, when the vehicle is not in the passing mode in the determination of step 32, it is determined whether there is an obstacle in the adjacent lane. If there is an obstacle, the process proceeds to step 34. If there is no obstacle, step 35 is performed. Proceed to.

In step 34, when it is determined in step 33 that there is an obstacle in the adjacent lane, the passing mode is set.
Proceed to step 35.

In step 35, the target line deviation ΔY
Is set to △ Y = 0, and the routine proceeds to step 36.

In step 36, the target lateral displacement YO is calculated as Y
It is calculated using the formula of O = Yopt + △ Y (Yopt: target line), and proceeds to step 37 (corresponding to target line setting means).

In step 37, the target steering torque Tr and the target steering angle θopt for obtaining the target lateral displacement YO calculated in step 36 are calculated. Then, a control command (motor current) for obtaining the target steering torque Tr and the target steering angle θopt is output to the motor 7.

In step 38, when it is determined in step 32 that the vehicle is in the passing mode, it is determined whether there is an obstacle in the adjacent lane. If there is an obstacle, the process proceeds to step 39. If there is no obstacle, the process proceeds to step 39. Proceed to 42.

In step 39, the relative speed and the relative distance to the obstacle are calculated, and the routine proceeds to step 40.

At step 40, the time t until the passing time t
s (passing time) is calculated based on the relative speed and relative distance to the obstacle, and the process proceeds to step 41.

In step 41, the passing transition time t
Timer settings of 0, t1, t2 are made, and step 42
Proceed to. Here, t0 is a passing transition start time, t1 is a passing time, and t2 is a passing transition end time. Steps 39 to 41 correspond to passing transition time setting means.

At step 42, the current timer is read, and the routine proceeds to step 43.

In step 43, it is determined whether or not the timer has exceeded the passing transition end time t2.
If it exceeds 2, the process proceeds to step 44, and if it does not exceed t2, the process proceeds to step 45.

In step 44, if the time has exceeded t2, the passing mode is cleared and the routine proceeds to step 45.

In step 45, the target line deviation ΔY is calculated based on the relationship between the time by the timer and the passing transition times t0, t1, t2, and the routine proceeds to step 36 (corresponding to the target line correcting means).

[When there is no obstacle] Automatic steering switch 1
When the vehicle is in the automatic steering mode with 3 on and there is no obstacle (such as an oncoming vehicle or preceding vehicle) passing by in the adjacent lane,
In the flowchart of FIG. 2, step 30 → step 31 → step 32 → step 33 → step 35 →
The flow proceeds from step 36 to step 37, and a control command (motor current) for obtaining the calculated target steering torque Tr and the target steering angle θopt is output to the motor 7.

Thus, for example, if the approximate center of the lane is set as the target line Yopt, the target line deviation ΔY becomes ΔY
Since = 0, the target lateral displacement YO becomes YO = Yopt, and the steering control is performed so that the own vehicle follows the set target line Yopt.

[Passing mode] Automatic steering switch 1
When the vehicle is in the automatic steering mode in which the vehicle 3 is ON and there is an obstacle passing in the adjacent lane, based on the determination that there is an obstacle in the adjacent lane in step 33 in the flowchart of FIG. The passing mode is set so that the obstacle outside the lane approaches and leaves in the direction of the own vehicle more. From the next control cycle, step 30 → step 31 → step 32 → step 38 → step 3
9 → step 40 → step 41 → step 42 → step 43 → step 45. In step 45, the target line which is a correction value for shifting the target lateral displacement YO from the target line Yopt to a direction where there is no obstacle outside the lane. The deviation ΔY is calculated.

Therefore, when overtaking the preceding vehicle in the adjacent lane while driving, passing by an oncoming vehicle on a road without a median strip, or passing by while seeing a stopped vehicle stopped outside the lane, etc. It is determined that the vehicle is in the passing mode, and the target lateral displacement YO is corrected to be shifted from the target line Yopt in a direction where there is no obstacle outside the lane. For example, when the vehicle passes an oncoming vehicle, as shown in FIG. The line will expand in the direction to avoid oncoming vehicles, giving the driver a sense of security.

[Setting of passing transition time] In the passing mode, the relative speed and the relative distance to the obstacle are calculated in step 39, and in step 40,
The passing time ts is calculated based on the relative speed and relative distance to the obstacle, and in step 41, based on the passing time ts, the passing transition times t0, t1, and t.
A timer setting of 2 is made. When the vehicle is in the passing mode, it is determined in step 38 whether there is an obstacle in the adjacent lane. Each time it is determined that there is an obstacle in the adjacent lane, the process proceeds to steps 39 to 41, and the passing transition times t0 and t1. , T2 are reset.

That is, although the CCD camera 11 directed to the front of the vehicle is used as an example of the obstacle detection means outside the lane, as shown in FIG. 4, the recognition angle of the image that can be captured by the CCD camera 11 is limited. There is an obstacle (large at about 45 degrees), and it is not possible to catch an obstacle in the area at the moment of passing and the area after passing.

Thus, when the next obstacle can be recognized by the CCD camera 11, the passing time ts is predicted, and the passing transition times t0, t1, t from the start of correction to the end of correction are predicted.
By setting 2, the target line correction for the adjacent obstacle can be reliably performed.

Further, by resetting the passing transition times t0, t1, and t2 until the very moment when the adjacent obstacle is captured in the image, the own vehicle and the adjacent obstacle are set at a distance from each other. The estimation error of the passing transition times t0, t1, and t2 can be reduced as compared with the case where the transition time is used as a fixed value for the correction.

[Correction of target line] In step 45, the target line deviation △ Y from the passing transition start time t0 (first set time) before the passing time t1 set with the passing time ts having a front-back width. , The maximum line deviation △ Ymax is maintained for the passing time t1, and the target line deviation △ after the passing time t1 elapses.
The value of Y is gradually reduced, and the target line deviation ΔY is set to zero when the passing transition end time t2 (second set time) has elapsed from the passing time t1.

Here, the passing time t1 is, as shown in FIG. 3, a time obtained by dividing a preset passing distance Lout by a relative speed Ve with respect to the obstacle, that is, t1 = Lout.
/ Ve. The maximum line deviation ΔYmax is set to be large in proportion to the relative speed Ve with respect to the next obstacle.

Therefore, when passing an oncoming vehicle, FIG.
As shown in FIG. 5, the line is slightly expanded so as to avoid the oncoming vehicle, and similarly, when passing the preceding vehicle, the line is slightly expanded so as to avoid the preceding vehicle as shown in FIG. The line will be rounded, and the driver and the following vehicle will not feel uncomfortable due to the natural obstacle avoidance operation of the vehicle.

Further, since the maximum line deviation △ Ymax is proportional to the relative speed Ve with respect to the next obstacle, when passing the next obstacle, the avoidance psychology of the driver who wants to escape as the passing speed is higher is higher. Target line correction. When the vehicle is traveling on a road with two or more lanes on one side, the maximum line deviation ΔYmax needs to be set to a small value so as not to surprise the following vehicle or the following lane.

Next, the effects will be described.

(1) In the passing mode in which the obstacle outside the lane approaches and separates from the front in the direction of the own vehicle, the target lateral displacement YO is set to the direction without the obstacle outside the lane by the target line deviation ΔY from the target line Yopt. In the passing mode, the traveling line of the own vehicle becomes a line that expands in a direction to avoid an adjacent obstacle, so that a sense of security can be given to the driver.

(2) In the passing mode, the relative speed and the relative distance to the obstacle are calculated, and the passing time ts
Is calculated by prediction based on the relative speed and relative distance to the obstacle, and the timer setting of the passing transition times t0, t1, and t2 is performed based on the passing time ts. In the case of a system in which the CCD camera 11 is directed toward the front of a vehicle having a certain obstacle, it is possible to reliably perform target line correction for an adjacent obstacle.

(3) When the vehicle is in the passing mode, it is determined whether there is an obstacle in the adjacent lane. Every time it is determined that there is an obstacle in the adjacent lane, the process proceeds to steps 39 to 41, and the passing transition times t0, t1 , T2 are reset, the passing transition times t0, t1, and t2 are reset until the very moment when the adjacent obstacle is captured in the image, so that the own vehicle and the adjacent obstacle can be separated from each other. The estimation error of the passing transition times t0, t1, and t2 can be reduced as compared with the case where the set passing transition time is used as a fixed value for correction.

(4) The value of the target line deviation ΔY is gradually increased from the time before the passing transition start time t0 to the passing time t1 set with the passing time ts having a width before and after the passing time ts. △ Ymax is maintained,
When the passing time t1 elapses, the value of the target line deviation ΔY is gradually reduced, and when the passing transition end time t2 has elapsed from the passing time t1, the target line deviation ΔY is set to zero. As shown in (2), the line is slightly expanded so as to avoid the next obstacle, and the natural obstacle avoidance operation of the vehicle does not give a sense of discomfort to the driver or the following vehicle.

(5) Since the maximum line deviation ΔYmax is set to be large in proportion to the relative speed Ve with respect to the next obstacle,
When passing by an adjacent obstacle, a target line correction that matches the avoidance psychology of a driver who wants to escape as the passing speed is higher can be achieved.

(6) As the lane information detecting means and the out-of-lane obstacle detecting means, a common CCD camera 11 for photographing the road ahead in the traveling direction and sending the video signal to the automatic steering controller 12 is used. The lane information detection unit and the obstacle detection unit outside the lane are detected by the image processing in the lane. In addition, it is possible to adopt the target line correction technology for obstacles outside the lane without adding a new member to the one provided with the lane information detecting means.

(Other Embodiments) In the first embodiment, an example in which the present invention is applied to a control device that applies a steering torque during automatic steering is described. However, the first embodiment is applied to a control device that applies a steering reaction torque during automatic steering. May be. In this case, control is performed such that the greater the degree of driver intervention, the smaller the steering reaction torque.

[Brief description of the drawings]

FIG. 1 is an overall system diagram showing an automobile steering system to which a lane following device according to a first embodiment is applied.

FIG. 2 is a flowchart illustrating a flow of an automatic steering control operation performed by an automatic steering control unit of the automatic steering controller according to the first embodiment.

FIG. 3 is a diagram showing a target line deviation for an oncoming vehicle passing by the lane tracking control device according to the first embodiment;

FIG. 4 is a diagram illustrating a camera view when the lane following control apparatus of the first embodiment passes an oncoming vehicle.

FIG. 5 is a diagram showing a target line deviation for a preceding vehicle passing by the lane following control device of the first embodiment.

[Explanation of symbols]

 Reference Signs List 1 steering wheel 2 steering shaft 3 universal joint 4 rack and pinion type steering gear box 5 side rod 6 worm wheel gear 7 motor 8 worm gear 9 electromagnetic clutch 10 steering angle sensor 11 CCD camera 12 automatic steering controller 13 automatic steering switch 14 steering torque sensor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Mohri 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Masayasu Shimakage F-term (reference) 3D032 CC01 CC08 CC20 CC30 DA03 DA15 DA16 DA22 DA23 DA76 DA77 DA84 DA88 DC09 DC38 DC40 DD02 DD17 EA01 EB04 EB11 EB12 EC23 EC27 GG01 5H180 AA01 CC04 CC24 LL01 LL02 LL09

Claims (6)

[Claims] An automatic steering actuator provided in a steering force transmission system for applying a steering torque or a steering reaction torque, a lane information detecting means for detecting a lane state of a road ahead, and a traveling lane of a target vehicle. A lane tracking device comprising: a target line setting device on which a target line is set; and an automatic steering control device for outputting, to the automatic steering actuator, a control command for causing the vehicle to follow the set target line during automatic steering. In the device, an out-of-lane obstacle detecting means for detecting an obstacle existing outside the lane, and based on the detection of the out-of-lane obstacle, is a passing mode in which the out-of-lane obstacle approaches and separates from the front in the own vehicle direction. A passing mode determining means for determining whether the target line is set in the target line setting means. Lane keeping apparatus characterized in that a target line correcting means for correcting the shift in the direction without obstruction. 2. The lane following apparatus according to claim 1, wherein a passing time is predicted based on a calculated relative distance and a relative speed to the detected out-of-lane obstacle, and correction is started based on the predicted passing time. A lane following device provided with a passing transition time setting means for setting a passing transition time from the time until the correction is completed. 3. The lane following apparatus according to claim 2, wherein the transition time setting means resets the passing transition time each time it is determined that there is an obstacle outside the lane based on the detection of an obstacle outside the lane. A lane following device characterized by the following. 4. The lane following device according to claim 2, wherein the target line correcting means sets the target line from a first set time earlier than a passing time set by giving a passing width to the passing time. Start the correction to gradually add the line deviation to the passing time, maintain the maximum line deviation for the passing time, gradually reduce the line deviation after the passing time, and reduce the line deviation when the second set time has passed from the passing time. A lane following device, which is a means for terminating the correction by setting it to zero. 5. The lane following device according to claim 1, wherein said target line correcting means is means for increasing a maximum line deviation in proportion to a relative speed with respect to an obstacle outside the lane. Lane following device. 6. The lane following device according to claim 1, wherein said lane information detecting means and said out-of-lane obstacle detecting means photograph a road ahead in a traveling direction, and automatically control the video signal based on the image signal. A lane following apparatus comprising: means for detecting a lane state and detecting an obstacle existing outside the lane by image processing by an automatic steering control means using a common camera sent to the lane tracking apparatus.