JP3351247B2 - Travel control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for detecting a lane boundary such as a white line to detect a lane and perform automatic traveling. It relates to traveling control in the case where detection has not been performed.

[0002]

2. Description of the Related Art For example, in addition to a travel control device for automatically following a vehicle while maintaining a distance between the vehicle and a preceding vehicle, and a device for maintaining a distance between the vehicle and a preceding vehicle while automatically adjusting a traveling speed. Therefore, a device for determining the traveling path of the vehicle and performing automatic steering is required. The device for performing this automatic steering detects a white line located on both sides of the vehicle from image data in front of the vehicle's road, detects a road using position information of a specific position of the detected white line, and detects the road. The steering amount is sequentially calculated so as to travel along.

[0003] However, depending on the environment on the road, such as blurring of the white line or reflection of a puddle formed on the white line, a part of the white line may not be detected. When the position where the white line cannot be detected coincides with the specific position (white line detection position) used for detecting the lane, the lane cannot be obtained, and the automatic traveling control has to be stopped. In addition, when approaching the preceding vehicle, the presence of the preceding vehicle makes it impossible to detect the white line at the white line detection position.Therefore, it is necessary to provide a sufficient inter-vehicle distance to detect the white line and stop following the preceding vehicle. Disappears.

In Japanese Patent Application Laid-Open No. Hei 4-306709, white line information of a portion that has already passed during traveling is temporarily stored, and a white line ahead of the vehicle is estimated based on the white line information. Is estimated so that traveling can be continued while adjusting the vehicle speed.

[0005]

However, in the prior art, the position of the white line on the road ahead of which is to be passed is estimated on the basis of the white line information of the portion which has already passed. In the case of a appearing road, the estimation is incorrect. That is, the estimation result is not always accurate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to more accurately estimate a lane boundary such as a white line used for lane detection when the lane cannot be directly detected. In addition, it is an object of the present invention to enable highly reliable travel control without stopping travel control.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, a first invention is to detect a lane boundary located in front of a lane of a vehicle, and to detect the lane boundary detected. A traveling control device for automatically traveling the vehicle along the lane determined on the basis of: lane boundary detecting means for sequentially detecting lane boundaries located in front of the lane of the vehicle from the image data; and the lane boundary on the image data. A first lane boundary line detection position used for detecting a lane among the lane boundary lines detected by the detection means, and each lane existing at a second lane boundary line detection position located ahead of the first lane boundary line detection position Lane boundary line information storage means for extracting and temporarily storing boundary line position information, and lane line detection means for detecting a lane based on positional information of the lane boundary line existing at the first lane boundary line detection position. If the lane boundary line cannot be detected at the first lane boundary line detection position, the lane boundary line is extracted when the lane boundary line exists at the second lane boundary line detection position, and the lane boundary line information storage means A lane is estimated using the past lane boundary line position information stored in.

According to a second aspect of the present invention, there is provided a travel control device for detecting a lane boundary located in front of a lane of a vehicle and automatically driving the vehicle along a lane determined based on the detected lane boundary. A lane boundary detecting means for sequentially detecting a lane boundary located in front of the lane of the vehicle, and a lane boundary storing a lane boundary located ahead of the own vehicle among the lane boundaries detected by the lane boundary detecting means. A lane information storage unit, a lane detection unit that detects a lane based on the lane boundary line position information existing at a lane boundary detection position used for lane detection among lane boundary lines stored by the lane boundary information storage unit. When the lane boundary line cannot be detected at the lane boundary line detection position, the lane boundary line that has been detected in the past and stored in the lane boundary line information storage unit cannot be detected. And estimating the road by using the positional information of the past lane boundary line corresponding to the line.

In other words, according to the above inventions, even if the lane boundary line cannot be detected at the lane boundary detection position used for lane detection, the undetectable lane boundary line itself is detected in the past. Since the position of the lane boundary line at the lane boundary line detection position is obtained using the position information, the lane can be accurately estimated.

[0010] In a third aspect based on the first or second aspect, there is provided a follow-up running means for performing a follow-up run using the past runway boundary line position information stored in the runway boundary line information storage means. It is characterized by. As a result, even when the lane boundary cannot be detected, the automatic following travel control can be continued without stopping based on the lane accurately estimated, and highly reliable travel control can be performed.

According to a fourth aspect of the present invention, in the first or second aspect, when stopping to approach the preceding vehicle using the past lane boundary position information stored in the lane boundary information storage means. It is characterized by having inter-vehicle distance control means.
Thus, even if the lane boundary line is not actually detected at the lane boundary detection position, the position of the lane boundary line at the lane boundary line detection position can be estimated by using the stored past position information. This makes it possible to bring the own vehicle closer to the preceding vehicle and stop it as compared with the related art.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a travel control device according to the present invention. Following EC
U (Electronic Control Uni)
t) 10, the image ECU 12 and the DGPS (Diff)
erential Global Positionion
ng System) 14 and a map database 16
And the inter-vehicle distance sensor 18 and the vehicle speed sensor 20 are connected. The image ECU 12 sequentially detects a white line in front of the track on the basis of image data captured by the on-board camera 22. The DGPS 14 combines pseudo-range correction information and carrier phase correction information with position information from a GPS device that detects the current position using satellite signals from communication satellites, and performs high-precision positioning up to the centimeter level. Obtain the current position of the vehicle. The map database 16 stores map information including nationwide road information and the like. The inter-vehicle distance sensor 18 detects, for example, an inter-vehicle distance from a preceding vehicle by irradiating an infrared radar toward the front and receiving a reflected wave. The vehicle speed sensor 20 is configured by a rotation sensor or the like that detects the number of rotations of the wheel shaft, and detects the traveling speed of the own vehicle.

In addition, the following cruise control ECU 10 is connected to acceleration / deceleration means 24 such as a throttle and a brake, which are to be controlled for the following cruise. The following cruise ECU 10 detects a lane based on data such as the above-described white line detection information from the image ECU 12, current position information from the DGPS 14, and link information including the road width from the map database 16, performs automatic steering control, and performs headway control. Inter-vehicle distance data from the distance sensor 18 and the vehicle speed sensor 2
By controlling the acceleration / deceleration means 24 and the like based on the vehicle speed from 0, the automatic following travel control is performed. In particular, the following cruise control ECU 10 in the present embodiment performs the image EC
Of the white lines detected by U12, as shown in FIG. 2, the first white line detection position P1 used for detecting the lane and the second white line detection position P located ahead of the first white line detection position P1.
2 is a lane boundary line position storage means for extracting and temporarily storing the position information of each white line existing in the line 2, and detecting the lane based on the position information (white line information) of the white line existing at the white line detection position P1. It is a detecting means. In the present embodiment, assuming that the lane is determined based on, for example, the position information of the white line 5 m ahead, the white line detection position P1 is 5 m ahead of the own vehicle. The white line detection position P2 is, for example, 5 m ahead of the white line detection position P1, that is, 10m ahead of the host vehicle.

A feature of the present embodiment is that even if a white line to be present at the first white line detection position P1 used for detecting a lane cannot be detected, the white line that could not be detected is detected at the white line detection position P2. If it has already been detected, the lane is detected using the position information of the white line detected at the white line detection position P2. As described above, the position of the white line at the white line detection position P1 is estimated using the white line information obtained when the white line that could not be detected at the white line detection position P1 was actually imaged in the past. Obtainable.

Next, the operation in the case of performing the automatic following running control in the present embodiment will be described with reference to the flowcharts shown in FIGS.

In FIG. 3, when the driver selects the automatic following mode, the automatic following control is started by satisfying predetermined conditions such as the current vehicle speed and the following distance (step 101). An automatic steering control process for detecting a white line based on the image data captured by the camera and performing automatic steering is performed (step 102). This automatic steering control process will be described with reference to the flowchart shown in FIG.

First, the image ECU 12 includes a vehicle-mounted camera 22.
Detects a white line from the captured image data (step 1
21). FIG. 5 is an example of an image captured while the vehicle-mounted camera 22 is traveling. Of these, FIG. 5B is an example of an image captured when a short time has elapsed since the image of FIG. is there. For example, if a part B of a white line ahead of the runway (hereinafter, simply referred to as “white line B”) is detected at a certain point at a white line detection position P2 10 m ahead (FIG. 5A), the vehicle travels. Eventually, it should be detected at the white line detection position P1 5 m ahead (FIG. 5B).

The follow-up traveling ECU 10 detects a white line detection position P1.
If the white line can be detected at the white line detection position P2 (step 122), the position information of each white line is extracted and temporarily stored in the built-in memory (step 123). Then, the following vehicle ECU 10 detects the traveling path based on the position information of the white line at the white line detection position P1 (step 124). For example, in FIG. 5A, when a part A of the white line to be present at the white line detection position P1 (hereinafter, simply referred to as “white line A”) can be detected, the travel path is detected using the detected position information of the white line A. Will do. Then, the following vehicle ECU 10 calculates the amount of steering based on the amount of deviation of the current vehicle position from the detected lane (step 12).
5) Perform automatic steering (step 126).

On the other hand, when the following cruise ECU 10 cannot detect a white line that should exist at the white line detection position P1 (step 122), it reads past positional information of the white line that should exist, and uses the positional information to read the running path. Is calculated (step 128). This operation will be described with a specific example. For example, in FIG. 5B, it is assumed that the white line B, which should originally exist at the white line detection position P1 5 m ahead, could not be detected for some reason such as reflection of a puddle. As shown in FIG. 5A, this white line B should exist at the white line detection position P2 when the white line A located 5 m before the white line B exists at the white line detection position P1. That is, since the white line information in the state shown in FIG. 5A when this white line A exists at the white line detection position P1 is stored in the internal memory of the following vehicle ECU 10 in step 123, the white line B is detected. The position of the white line B at the white line detection position P1 can be calculated from the white line information when it exists at the position P2. Therefore, even if the white line B cannot be detected when it exists at the white line detection position P1, it can be easily estimated. The position of the white line B at the white line detection position P1 is estimated based on data obtained by actually imaging the white line B in the past and the running results such as the steering amount from when the white line B reaches the white line detection position P1 to the white line detection position P1. Therefore, even if there is a change in the shape of the road on which the vehicle is going to travel, such as a turning angle, no more erroneous estimation is performed. Therefore, when the lane can be calculated based on the past white line information (step 129), the steering amount is calculated from the lane and the automatic steering is performed (steps 125 and 126). Then, the fact that automatic steering control is possible is set (step 127). If the runway cannot be calculated in step 128 (step 129), it is set that automatic steering control cannot be performed (step 130).

Returning to FIG. 3, if the automatic steering control cannot be performed in step 103, the automatic follow-up running control ends. If the automatic steering control is possible, the running control to follow the preceding vehicle is performed (step 104). Following ECU 10
In this embodiment, the own vehicle travels while maintaining a predetermined inter-vehicle distance while sequentially detecting the inter-vehicle distance to the preceding vehicle and the vehicle speed.In the present embodiment, the following traveling is performed by a method similar to the conventional method. The detailed description is omitted. When the preceding vehicle is stopped, the position of the white line can be estimated using the stored past white line information without actually detecting the white line at the white line detection position P1. The vehicle can be stopped closer to the preceding vehicle.
In the present embodiment, since the white line information of 10 m ahead is required, the start after the own vehicle is stopped, the inter-vehicle distance with the preceding vehicle is opened by 10 m or more, and the white line is detected from the image data at the white line detection position P2. It is desirable to do this when it is possible.

If the following running control is possible (step 105), the above processing is repeated unless there is an instruction from the driver or the like to end the automatic following running control (step 10).
6).

As described above, according to the present embodiment, even if a white line cannot be detected at the white line detection position used for detecting a lane, the white line itself is corrected using white line information obtained in the past. And the position of the white line is estimated, so that the running path can be obtained. As a result, the automatic following travel control can be continued without being stopped. Further, in the present embodiment, since the position of the white line is estimated by effectively utilizing the past white line information of the white line that could not be detected, a more accurate running path can be obtained, and as a result, Thus, it is possible to perform highly reliable following running control.

In this embodiment, the white line detection positions are 5 m and 10 m away from the host vehicle, and the white line detection positions are located on both sides as shown in FIG. The setting of the position is not limited to this, and can be changed as appropriate.

In the above-described embodiment, the lane is detected by using a white line which may exist on both sides of the lane as the lane boundary. However, the present invention is not limited to this. It is also feasible to detect grooves and grooves.

Embodiment 2 FIG . The automatic follow-up running control in the present embodiment is almost the same as in the first embodiment. However, the present embodiment is characterized by running control when the preceding vehicle is stopped. Next, the automatic following driving control in the present embodiment will be described with reference to the flowchart shown in FIG.

When the driver selects the automatic following travel mode, the automatic following travel control is started by satisfying predetermined conditions such as the current vehicle speed and the following distance (step 2).
01), the image ECU 12 detects a white line from the image data captured by the onboard camera 22 in the same manner as in the first embodiment (step 202). When the white line is detected (step 203), the following vehicle ECU 10 stores the detected position information of the white line (white line information) in the built-in memory (step 204). Further, the lane is detected based on the detected position of the white line (step 205). In a normal case, since the track can be detected, automatic steering control is performed so as to travel along the track (step 207). When the preceding vehicle is not stopped (step 208), the vehicle distance control is performed so as to maintain the required amount of vehicle distance, and the automatic following operation is performed (step 209). In this case, the white line at the white line detection position necessary for detecting the traveling road is not hidden by the preceding vehicle and cannot be detected.

Here, a description will be given of a process of the inter-vehicle distance control (step 210) according to the present embodiment for stopping the preceding vehicle and stopping the own vehicle behind the preceding vehicle, with reference to FIG. FIG. 7 is a diagram showing the transition from the rear of the stopped preceding vehicle 30 gradually approaching until the own vehicle 32 is stopped.

First, as described above, in step 204, the position information of the white line detected by the image ECU 12 from the image data captured by the vehicle-mounted camera 22 is stored in the internal memory of the following vehicle ECU 10. In FIG. 7A,
Since the front of the white line imaged by the on-vehicle camera 22 is limited by the rear part of the preceding vehicle 30, the following traveling ECU
10 stores the white line information up to the position E. In the present embodiment, the white line information of the track on which the vehicle 32 has passed is unnecessary, and may be deleted from the internal memory as needed. In the present embodiment, a white line detection position for detecting a lane is defined as a position S. This position S corresponds to the white line detection position P1 in the first embodiment.

The own vehicle 32 reduces the vehicle speed while the preceding vehicle 30
Gradually approach. Until the white line detection position S can no longer be detected by the trailing portion as shown in FIG. 7B, it is possible to detect the lane based on the white line at the white line detection position S detected based on the image data and perform follow-up traveling control. (Steps 202 to 207). Here, it is assumed that the own vehicle further approaches the preceding vehicle 30, and as shown in FIG. 7C, the white line detection position S cannot be detected by the tail part (step 2).
03). Here, in the present embodiment, the lane is calculated by reading the white line information stored in the past (step 211). That is, in the related art, if the white line at the white line detection position S cannot be detected by the trailing portion, the follow-up traveling control cannot be performed. Therefore, the vehicle 32 must be stopped at that point, but in the present embodiment, Since the white line information up to position E has been acquired and stored in the past,
By using the white line information that has been detected in the past, the position S ′ of the white line that cannot be actually detected can be easily estimated. Therefore, since the travel path can be calculated based on the result of the white line position estimation at the position S ′, even if the white line detection position S cannot be detected by the tail portion, the own vehicle 32 is further advanced, and the inter-vehicle distance is further reduced to make the own vehicle 32 Can be stopped. Needless to say, the inter-vehicle distance at the time of the stop is different from the inter-vehicle distance to be maintained at the time of traveling, but in the past, the inter-vehicle distance at the stop could only be reduced to a position where a white line could be detected. In the form,
The vehicle can be stopped by following the preceding vehicle 30 up to the target inter-vehicle distance at stop.

FIG. 8 is a diagram showing the relationship between the vehicle speed and the inter-vehicle distance. The straight line A in FIG. 8 is based on the inter-vehicle distance control during stop (step 210), and the straight line B is based on the inter-vehicle distance control during traveling (step 209).
In the present embodiment, the inter-vehicle distance at stop can be made very short.

As described above, according to the present embodiment, the position of the white line can be estimated by using the stored past white line information without actually detecting the white line at the white line detection position S. The vehicle 32 can be brought closer to the preceding vehicle 30 and stopped. In the present embodiment, if the preceding vehicle 30 starts moving and a white line can be detected from the image data at the white line detection position S, the vehicle can perform automatic following travel. The self-vehicle 32 may be started when the vehicle travels a distance.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a travel control device according to the present invention.

FIG. 2 is a conceptual diagram showing a white line detected from imaging data.

FIG. 3 is a flowchart showing an operation of automatic following running control performed in the first embodiment.

FIG. 4 is a flowchart illustrating an operation of an automatic steering control performed in the automatic following control according to the first embodiment.

FIG. 5 is a diagram illustrating an example of an image captured by a vehicle-mounted camera.

FIG. 6 is a flowchart illustrating an operation of an automatic following running control performed in a second embodiment.

FIG. 7 is a diagram used to explain inter-vehicle distance control at a stop in a second embodiment.

FIG. 8 is a diagram showing a relationship between a vehicle speed and an inter-vehicle distance.

[Explanation of symbols]

10 Following running ECU, 12 Image ECU, 14 DG
PS, 16 map database, 18 inter-vehicle distance sensor, 20 vehicle speed sensor, 22 vehicle-mounted camera, 24 acceleration / deceleration means, 30 preceding vehicle, 32 own vehicle.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-303625 (JP, A) JP-A-6-225308 (JP, A) JP-A-7-198349 (JP, A) JP-A-8-1983 96299 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06T 7/60 B60R 21/00 620 G05D 1/02 G06T 1/00 G08G 1/16 JICST file (JOIS)

Claims (4)

(57) [Claims] 1. A travel control device for detecting a lane boundary located ahead of a lane of a vehicle and automatically driving the vehicle along a lane determined based on the detected lane boundary. A lane boundary line detecting means for sequentially detecting lane boundary lines located at a first lane boundary line detection position and a first lane boundary line detection position used for detecting a lane among lane boundary lines detected by the lane boundary line detection means on image data; Lane boundary information storage means for extracting and temporarily storing position information of each lane boundary present at a second lane boundary detection position located ahead of one lane boundary detection position; and the first lane boundary Lane detection means for detecting a lane based on the position information of the lane boundary present at the line detection position, and the lane detection means cannot detect the lane boundary at the first lane boundary detection position. In the case, the lane boundary is extracted when the lane boundary line is present at the second lane boundary line detection position, and the lane is estimated using the past lane boundary line position information stored in the lane boundary information storage means. Traveling control device. 2. A travel control device for detecting a lane boundary located in front of a lane of a vehicle and automatically driving the vehicle along a lane determined based on the detected lane boundary. Lane boundary line detecting means for sequentially detecting lane boundary lines located in the vehicle; lane boundary line information storage means for storing lane boundary lines located ahead of the vehicle among the lane boundary lines detected by the lane boundary line detecting means And lane detection means for detecting a lane based on position information of lane boundary lines existing at lane boundary detection positions used for lane detection among lane boundary lines stored in the lane boundary information storage means. When the lane boundary line cannot be detected at the lane boundary line detection position, the lane line detecting means detects the lane boundary line that has been detected in the past and stored in the lane boundary line information storage means and cannot be detected. Travel control device and estimates the road by using the position information of the past lane boundary lines. 3. The traveling control device according to claim 1, wherein the following traveling unit performs the following traveling using the past lane boundary position information stored in the lane boundary information storage unit. A travel control device comprising: 4. The travel control device according to claim 1, wherein the approach to the preceding vehicle is stopped using the past lane boundary position information stored in the lane boundary information storage means. A travel control device comprising stop-time inter-vehicle distance control means.