JP2002248964A - Leading vehicle following control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a preceding vehicle following control device capable of stably following a curved section. SOLUTION: A radar apparatus 1 for recognizing the presence of a preceding vehicle.
A target vehicle recognition controller 2 for setting a preceding vehicle as a target for performing tracking control, and a vehicle speed sensor 3
And a steering angle sensor 4. Further, the target vehicle recognition controller 2 includes a host vehicle lane preceding vehicle recognition unit 2a.
A road shape estimating unit 2b, a lock-on processing unit 2c,
A target vehicle determination unit is provided. Then, based on data detected by the vehicle speed sensor 3 and the steering angle sensor 4, a curve radius of a road on which the host vehicle travels is obtained. If the curve radius is equal to or smaller than a predetermined value (when the curve is tight), The preceding vehicle is locked on, and the preceding vehicle is set as a target vehicle. As a result, the vehicle can stably follow the preceding vehicle even in a curved section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preceding vehicle follow-up control device for an automobile, and more particularly to a preceding vehicle follow-up control device that operates effectively when traveling on a curve section where recognition of the preceding vehicle to be followed tends to cause errors. About.

[0002]

2. Description of the Related Art Heretofore, a preceding vehicle traveling on its own lane has been recognized by a preceding vehicle recognizing means, and the recognized preceding vehicle has been transmitted to a travel control device while measuring the distance between the vehicles by a distance measuring means. There is known a preceding vehicle following control device that automatically follows a predetermined distance. This kind of preceding vehicle following control device determines that the preceding vehicle is present on the own lane and performs the following control when the lateral deviation between the own vehicle and the preceding vehicle is within a predetermined value. Operates effectively when the vehicle is substantially straight, but especially in a curved section, when it is determined that the preceding vehicle has deviated from its own lane despite traveling on its own lane, or when traveling on another lane. A vehicle may be erroneously recognized as a preceding vehicle traveling on its own lane. Due to such erroneous recognition, there is a problem that the tracking control operation is frequently turned on and off.

[0003] In order to solve this problem, for example, in the invention disclosed in Japanese Patent Application Laid-Open No. Hei 10-86688, a plurality of preceding vehicles traveling ahead of the host vehicle are imaged by an imaging device, and the images are taken. An image is displayed on a display device, and on this display screen, the driver specifies a vehicle to be followed by performing a selection operation using the input device. This makes it possible to follow the vehicle to be followed even in a curved section, and solves the problem that the following control operation is frequently turned on and off in the curved section.

[0004]

However, in such a conventional preceding vehicle follow-up control device, in order to select the follow-up target vehicle, the driver must perform an operation for selecting the follow-up target vehicle from the input device each time. Therefore, there is a problem that the operation is troublesome.

The present invention has been made in view of the above problems, and detects a curve radius of a traveling road when traveling on a curved section, and when the curve radius is smaller than a predetermined value, that is, when the curve radius is tight, In the case of a curve, it is an object to provide a preceding vehicle following control device that can stably follow the vehicle even in a curved section by locking on a preceding vehicle traveling immediately adjacent to the own vehicle as a following vehicle.

Further, it is determined in advance that the preceding vehicle to be followed has entered a curved section from a straight road while the own vehicle is still traveling on a straight line, and the preceding vehicle is locked on as a target vehicle to be followed and the following traveling is performed. It is intended to provide a possible preceding vehicle following control device.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention described in claim 1 of the present application is directed to a preceding vehicle recognizing means for recognizing a preceding vehicle traveling ahead of the own vehicle in a traveling lane. And a travel control means for controlling travel of the host vehicle so as to travel while maintaining a predetermined distance from the preceding vehicle. When the curve radius determined by the determining means and the road shape determining means is smaller than a predetermined value, the leading vehicle recognized by the preceding vehicle recognizing means is locked on as a vehicle to be followed, and then the road shape is determined. A lock-on processing means for releasing the lock-on when the curve radius obtained by the determination means is equal to or more than a predetermined value.

According to a second aspect of the present invention, a preceding vehicle recognizing means for recognizing a preceding vehicle traveling ahead of the own vehicle in the traveling lane, and traveling with a predetermined distance from the recognized preceding vehicle. In a preceding vehicle follow-up control device including traveling control means for controlling traveling of the own vehicle, a road shape determining means for obtaining a curve radius of a road ahead of the own vehicle, and a curve radius obtained by the road shape determining means are If it is smaller than the predetermined value, the preceding vehicle recognized by the preceding vehicle recognizing means is locked on as the vehicle to be followed, and thereafter,
Lock-on processing means for releasing the lock-on when the curve radius determined by the road shape determination means is equal to or more than a predetermined value.

According to a third aspect of the present invention, the road shape determining means includes an image capturing means for capturing an image of a front of a traveling road,
Image processing means for extracting a partition line from image data captured by the image capturing means, and curve radius estimating means for estimating a curve radius of a road ahead of the host vehicle based on the partition line. And

According to a fourth aspect of the present invention, the road shape determining means includes a stationary object detecting means for detecting a stationary object existing on the road in front of the host vehicle, and a position information of the detected stationary object. And a curve radius estimating means for estimating a curve radius of a road ahead of the own vehicle.

According to a fifth aspect of the present invention, the lock-on processing means determines that the curve radius determined by the road shape determining means is smaller than the predetermined value.
When it is determined that the curve radius has become equal to or greater than a predetermined value, the lock-on is released after a lapse of a predetermined time from the determination that the curve radius is equal to or greater than the predetermined value.

According to a sixth aspect of the present invention, when the lock-on processing means determines that the curve radius determined by the road shape determination means is smaller than the predetermined value,
The smaller the curve radius is, the longer the time from when the curve radius becomes a predetermined value or more to when the lock-on is released is set longer.

[0013]

According to the first aspect of the present invention, if the curve radius of the road at the traveling position of the own vehicle determined by the road shape determining means is smaller than a predetermined value, the preceding vehicle The leading vehicle recognized by the recognizing means is locked on as the following vehicle (target vehicle) to perform the following travel, and then the curve radius of the road at the traveling position of the own vehicle determined by the road shape determining means is determined. When the value is equal to or more than the value, the lock-on of the vehicle to be followed is released, so that, for example, the driver does not need to perform a troublesome operation even when the own vehicle is traveling on a curved section.

According to the second aspect of the present invention, when the curve radius of the road ahead of the own vehicle determined by the road shape determination means is smaller than a predetermined value, the preceding vehicle recognized by the preceding vehicle recognition means. If the curve radius of the road ahead of the own vehicle obtained by the road shape determining means becomes a predetermined value or more, the lock-on is released. Even when traveling, the vehicle ahead can be locked on when it recognizes the presence of a curve section ahead of the vehicle,
The driver does not need to perform cumbersome operations.

According to the third aspect of the present invention, a partition line (white line or yellow line) drawn on the road is extracted from the image data obtained by imaging the front of the host vehicle, and the host vehicle is extracted based on the partition line. Since the curve radius of the road ahead is estimated, the curve radius can be easily estimated using a known technique.

According to the fourth aspect of the present invention, since the curve radius of the road is estimated from the position information of a stationary object such as a guardrail or a side wall in front of the own vehicle or a continuous road sign, for example, a partition line is drawn. The curve radius can be estimated with high accuracy even on a road that is not covered.

According to the fifth aspect of the present invention, when the road shape is a sharp curve, the curve section tends to be continuous thereafter. From the point where the curve changes to the other curve)
In the above, by delaying the lock-on release for a predetermined time, the lock-on release is not performed even when the curvature change point is reached, and the vehicle to be followed continues to follow the vehicle.
On a road with a continuous curve, lock-on setting and lock-on release are performed alternately and frequently, resulting in unstable control and avoiding erroneous recognition of the vehicle to be followed. it can.

According to the sixth aspect of the present invention, the lock-on release delay is set such that the longer the sharper the curve, the longer the delay time, that is, the longer the detected curve radius, the more the lock-on release is performed. Since the release time is sequentially delayed, lock-on release can be appropriately performed.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment First, a first embodiment will be described. The first embodiment corresponds to the first, fifth, and sixth aspects, and detects a curve radius of a road at a traveling position of a host vehicle to lock on a target vehicle (vehicle to be followed), that is, to follow the vehicle. The vehicle is fixed while traveling on a curved section, and when the vehicle exits the curved section, the lock-on is released, and the control proceeds to the normal following control. As shown in FIG. 1, the preceding vehicle following control device according to the first embodiment includes a radar device 1, a target vehicle recognition controller 2, and an inter-vehicle distance control controller 5, and further includes a vehicle. It is connected to a mounted vehicle speed sensor 3 and a steering angle sensor 4. The preceding vehicle following control device is activated by turning on a main switch (not shown).

The radar device 1 is realized by a laser radar, a millimeter-wave radar, or the like. The radar device 1 recognizes an object such as a preceding vehicle or a road side wall, measures the distance and direction of the object, and measures the distance and direction of the own vehicle. It outputs relative position coordinates (X, Y) with respect to a plurality of objects located in front of a preceding vehicle or the like.

The target vehicle recognition controller 2 includes a CPU as a microcomputer and an RA as a memory.
A road shape estimating unit (including an M, a ROM, an input / output interface circuit, and the like) that calculates a curve radius of a road on which the host vehicle is currently traveling based on data detected by the vehicle speed sensor 3 and the steering angle sensor 4 ( Road shape determination means) 2
b, and when the road shape estimating unit 2b recognizes that the vehicle is in a curve section, the vehicle ahead of the own lane that recognizes the nearest preceding vehicle ahead from among a plurality of front objects captured by the radar device 1. A vehicle recognizing unit 2a, a lock-on processing unit 2c for locking on the preceding vehicle recognized by the own lane preceding vehicle recognizing unit 2a during traveling on a curve section, and a vehicle locked on by the lock-on processing unit 2c. Is determined as a target vehicle, and a target vehicle determination unit 2d that outputs the position data of the target vehicle to the following distance control controller 5. Inter-vehicle distance control controller 5
Is to control the traveling of the own vehicle such that the target vehicle and the own vehicle travel at a predetermined inter-vehicle distance.

Next, the operation of the first embodiment will be described with reference to FIGS.
It will be described based on. FIG. 2 is an explanatory diagram showing a road shape and a detection state of a preceding vehicle detected by radar, and FIG.
Target vehicle B (see FIG. 2) to be followed (see FIG. 2)
4 is a flowchart for explaining an operation of the target vehicle recognition controller 2 for outputting the position data of the target vehicle recognition controller 5 to the inter-vehicle distance control controller 5.

<Signal input and calculation of curve radius>
When the system is started by turning on the main switch by the driver (step ST100 in FIG. 3), the radar device 1 scans the front of the host vehicle and stores the position coordinates (Xn, Yn) of a plurality of preceding vehicles in the target vehicle recognition controller 2. (Step ST101). Next, receiving the vehicle speed signal of the own vehicle output from the vehicle speed sensor 3, the road shape estimating unit 2b calculates the speed of the own vehicle (step ST102).

Next, the rotation angle signal of the steering wheel output from the steering angle sensor 4 is output to the road shape estimation unit 2.
b. The road shape estimating unit 2b receives inputs from the vehicle speed sensor 3 and the steering angle sensor 4 and calculates a curve radius of a road on which the own vehicle runs (step ST).
103). Here, the steering angle of the vehicle running at the vehicle speed V is θ
Is given by the following equation (1).

R = (1 + A · V ² ) · N · L / θ (1) where A is a stability factor that is a value specific to the vehicle, N is a steering gear ratio, and L is a wheel base of the vehicle. It is.

<Determination of Curve Section> Next, it is determined whether or not the value of the calculated curve radius R is smaller than a predetermined value. In this embodiment, the curve radius R
Is set to R = 600 m, and it is determined whether or not the curve radius of the road on which the vehicle is currently traveling is a curve steeper than R600 m (step ST104). This curve radius can be set arbitrarily. For example, when the vehicle follows the preceding vehicle with a headway distance of 50 m, the lateral deviation of the preceding vehicle is about 2 m in the curve of R600 m, and the direction detection accuracy and the radar In this embodiment, the threshold value R is set to 600 m because the influence of the steering angle and the vehicle radius on the curve radius estimation accuracy increases the possibility of erroneous determination as a vehicle traveling in an adjacent lane. I have.

<Determination of Substantially Straight Section> Step ST103
If the curve radius calculated in the processing of (a) is a large curve of 600 m or more (NO in step ST104), the target vehicle determination unit 2d sets a constant lane width along the calculated curve radius (generally, 3. (A value of about 5 m is often used.) The position coordinates of a plurality of objects input from the radar device 1 are referred to the own lane estimation range having the own vehicle lane estimation value, and the vehicle closest to the front of the own lane is referred to as the own vehicle. (Step ST107).

The vehicle to be followed which uses the preceding vehicle immediately adjacent to the determined lane in the inter-vehicle distance control, that is,
The target vehicle is registered in the target vehicle determination unit 2d (step ST108). Then, the step S
Returning to T101, the following procedures are sequentially executed.

<Operation in Curve Section> Step ST1
If it is determined in 04 that the curve is a sharp curve with a radius of 600 m or less (YES in step ST104),
Target vehicle to be followed by the target vehicle determination unit 2d,
That is, it is determined whether or not the target vehicle exists (step ST109). If the target vehicle does not exist, the process returns to step ST101, and the following procedure is repeated.

<Set Lock On> Step ST10
If the target vehicle exists in step 9 (YES in step ST109), the target vehicle determining unit 2d determines whether lock-on is set for the target vehicle (step ST110). . If not set (N in step ST110)
O), lock-on is set by the lock-on processing unit 2c (step ST111).

Once the lock-on is set as the preceding vehicle (target vehicle) to be followed, the lock-on operates so as to maintain the handling as the target vehicle even if the position of the vehicle is out of the range of the lane judgment. Things.

Next, based on the magnitude of the curve radius calculated in the process of step ST103, the time from when it is determined that the road is a substantially straight road through the curve section until the lock-on is released. Is set (step ST112), and the locked-on preceding vehicle is registered in the target vehicle determination unit 2d as a target vehicle to follow (step ST113).
Returning to step ST101, the following procedure is executed.

<Setting of Lock-on Release Delay Time> FIG.
Is a graph showing a relationship between a curve radius and a time from when the vehicle enters a substantially straight road after passing through a curve section until the lock-on is released as a vehicle to be followed. Considering that it is common to drive at low speeds on sharp curves,
The smaller the curve radius, the longer the lock-on release time, ie, the longer the lock-on release delay time.

In this embodiment, as shown, the delay time is 10 seconds at a curve radius of 100 m and 0 second at a curve radius of 600 m.
The delay time is set so as to linearly change up to 0 m during this time.

As described above, the lock-on release delay time is generally set such that the steeper the curve that first enters, the steeper the curve is thereafter, the sharper the curve.
The lock-on release as the target vehicle is not immediately performed at the change point of the curvature of the curve, that is, the straight-on road portion at the change point from one curve to the other curve, but the lock-on release is performed after a predetermined delay time. By doing so, it is possible to prevent the setting and release of the lock-on from being performed frequently, and to stabilize the follow-up control.

<Continuation of Lock-On> Step ST110
If the lock-on process has already been performed on the target vehicle in the process (3) (YES in step ST110)
S), a process of following the same vehicle as the target vehicle is performed, and vehicles that match the same vehicle conditions recognized as the target vehicle from the preceding vehicle data detected by the radar device 1 (Step S
T114). The determination as to whether or not the vehicles are the same is made based on whether or not the amount of change in the X and Y coordinates and the amount of change in the relative speed of the detected object are within predetermined ranges.

If there is a preceding vehicle that satisfies the same vehicle condition (YES in step ST114), lock-on is continued for the preceding vehicle (step S114).
T115), the lock-on target vehicle is registered in the target vehicle determination unit 2d as a target vehicle to be followed.

<Release of lock-on> Step ST114
Is determined that there is no preceding vehicle that matches the same vehicle condition (N in step ST114).
O), it is determined that the target vehicle to be followed has deviated from its own lane due to a lane change or the like, and registration as the target vehicle is reset (step ST116), and step S116 is performed.
Returning to T101, the following procedure is executed.

On the other hand, in the second and subsequent steps of the procedure shown in the flowchart, it is determined whether or not the radius calculated in step ST104 is a gentle curve of 600 m or more, and whether lock-on is set in step ST105. (YES in step ST105)
S), it is determined whether or not the lock-on release delay time when the lock-on is set has elapsed (step ST106). If the lock-on release delay time has not elapsed, step ST is performed to continue lock-on.
The process proceeds to 114, and the same procedure as described above is executed.

FIG. 2 shows the relationship between the own vehicle A and the preceding vehicle B according to the road shape. In FIG. 2A, the own vehicle A and the preceding vehicle B have the same straight line. The vehicle B is on the lane, and is determined as a preceding vehicle in the own lane. Note that a triangle denoted by reference numeral D1 indicates a detection range of the radar device 1.

FIG. 6B shows a state when the vehicle enters the curve. When the two vehicles are on the same turning radius, the preceding vehicle B exists in the horizontal field of view of the radar device 1. If this is the case, it is determined as a preceding vehicle in the own lane.

FIG. 4C shows an S-shaped curve section. When the host vehicle A has entered the curvature change point of the curve, the preceding vehicle B has already entered the next curve. In this case, since the own vehicle is on a straight line, the determination of the own lane itself is performed within the range shown by the broken line.
In the case shown in the drawing, the preceding vehicle B is within the field of view of the radar, but deviates from the assumed lane of the own lane (broken line portion). Becomes unrecognized. However, by performing the lock-on processing described above, the preceding vehicle B captured in the field of view of the radar can be handled as a target vehicle.

As described above, in the preceding vehicle following control apparatus according to the first embodiment, when it is determined that the own vehicle is traveling on a curve having a curve radius equal to or smaller than the predetermined value, the own vehicle The vehicle ahead of the vehicle is locked on and continues to be recognized as the target vehicle, then exits the curve, and determines that the vehicle is traveling on a road (substantially straight road) having a curve radius equal to or greater than a predetermined value. Since the lock-on is released, the lock-on and the lock-on release can be performed without bothering the driver.

Further, it is determined that the radius of the curve is smaller than a predetermined value,
After that, the lock-on is released after a predetermined time has elapsed after it is determined that the vehicle is equal to or more than the predetermined value. Therefore, when traveling on an S-shaped curve or the like, the same preceding vehicle is kept locked on even at the curvature change point of the curve. And can run stably. Further, the predetermined time until the lock-on is released is set to be longer as the curve radius at the time of lock-on is smaller, so that lock-on control suitable for road conditions can be performed.

{Second Embodiment} Next, a second embodiment of the present invention will be described. The second embodiment is claimed in claims 2 and 3.
5 and 6, which is different from the first embodiment, even when the own vehicle is still traveling on a straight road, when the preceding vehicle enters the curve section, The point is that the curve radius is determined.

FIG. 5 is a diagram showing the system configuration of the second embodiment. In the figure, the system configuration according to the second embodiment is different from the system configuration according to the first embodiment (see FIG. 1) in that a front running path such as a CCD camera as an input sensor to the target vehicle recognition controller 2 and the like. A camera device 6 for imaging the vehicle is added. Further, as internal functions of the target vehicle recognition controller 2, an image processing unit 2e and a forward traveling road curve radius estimating unit 2f are added. Other configurations are the same.

Next, the operation of the second embodiment will be described with reference to the schematic diagram shown in FIG. 6 and the flowchart shown in FIG. The same operation parts as those in the flowchart of FIG. 3 shown in the first embodiment are omitted.

First, when the system is started by turning on the main switch by the driver (step ST1)
00), as in the first embodiment, radar ranging data input (step S101), vehicle speed signal input and vehicle speed calculation (step ST102), steering angle signal input, and turning curve radius R calculation (step ST103) are performed. .

<Input of Image Data and Extraction of White Line> The camera device 6 captures an image of the traveling road ahead of the host vehicle, and transmits the captured data to the image processing unit 2 e of the target vehicle recognition controller 2. The image processing unit 2e receives the input of the imaging data of the front traveling road (step ST201), creates an image based on the data, and performs a shading process on the image so that only the white line (partition line) of the road is obtained. Is extracted.

Since this white line image is a perspective image (see FIG. 6A) as viewed from the vicinity of the driver's seat of the vehicle, the image processing unit 2e converts the perspective image into a planar image (FIG. 6B). )
(Refer to step ST202). In the present embodiment, a continuous white line will be described as an example of a partition line, but the present invention is not limited to this, and may be applied to a partition line of another color such as a yellow line or a broken line. it can.

<Calculation of Curve Radius of Forward Road> The preceding vehicle ahead on the own lane is illuminated by the curve radius of the own vehicle traveling path determined from the position of the preceding vehicle detected by the radar device 1 and the steering angle and the like. The vehicle is determined (step ST203). When the presence of the preceding vehicle is confirmed by this determination (YES in step ST204), the distance L to the vehicle is set as a forward curve radius calculation point (step ST205). When the preceding vehicle is not detected in the process of step ST204 (step ST2
04 (NO), the distance L is temporarily set to 50 m (step ST206). In this provisional setting, the distance to the preceding vehicle being followed by the preceding vehicle following control is normally set to about 2 seconds between vehicles, so the distance to the preceding vehicle being followed at 100 km / h is about 50 m. Therefore, the target point distance L for estimating the curve radius is set near the target point distance L.

As shown in FIG. 6 (c), the preceding vehicle traveling road curve radius estimating unit 2f shown in FIG. 5 uses the distance L to the preceding vehicle on the white line E1 extracted by the image processing unit 2e.
Alternatively, a point corresponding to the temporarily set target distance L [FIG.
(Point P1 of (c))], a tangent line E2 is set, and the inclination θ of the road at the position of the preceding vehicle with respect to the own vehicle is calculated (step ST).
207). The curve radius R is calculated from the relationship between the distance L and the tilt angle θ by the following equation (2) (step ST208): R = L / sin θ (2) Once the curve radius R is obtained, Are the same as in the first embodiment, and are the same as those in step ST104 shown in FIG.
Perform the following steps: The description thereof is the same as that of the above-described first embodiment, and will not be repeated.

As described above, according to the preceding vehicle following control device according to the second embodiment, the camera device 6 captures an image of the front of the host vehicle, processes the image, and extracts a partition line. The curve radius of the road ahead of the host vehicle is determined based on the partition line. Therefore, since the preceding vehicle can be locked on when the existence of the curve section ahead of the own vehicle is recognized, the lock-on control can be performed more reliably.

{Third Embodiment} Next, a third embodiment will be described. The third embodiment is described in claims 2, 4, 5, and 6.
In the same manner as in the second embodiment,
Even when the own vehicle is still traveling on a straight road, the curve radius is determined when the preceding vehicle enters the curve section.

FIG. 8 is a diagram showing a system configuration according to the third embodiment. In the figure, the radar device 1 used in the third embodiment has a position coordinate (Xn, Yn) and a relative speed Vrn (n = n) for a plurality of targets (for example, 10 targets).
A millimeter wave radar device capable of measuring 1 to 10) is used.

Regarding the target vehicle recognition controller 2, in the system configuration in the first embodiment shown in FIG. 1, a plurality of stationary objects are obtained from the position coordinate information and the relative speed information about a plurality of forward objects output from the radar device 1. A stationary object recognizing unit 2g for recognizing position coordinates, and a forward road shape estimating unit 2h for calculating a curve radius of a road near the stationary object from the arrangement information of the stationary objects obtained by the stationary object recognizing unit 2g are added. Is done. The output of the forward road shape estimating unit 2h is supplied to the lock-on processing unit 2c, and the lock-on process for the preceding vehicle is performed.

The rest of the system configuration is the same as the system configuration in the first embodiment (see FIG. 1), and a description thereof will be omitted.

Next, the operation of the third embodiment will be described.
FIG. 11 is a flowchart for explaining the operation of the third embodiment, and portions common to the first embodiment are denoted by the same step numbers.

First, when the system is started by turning on the main switch by the driver (step ST1)
00), distance measurement data from the radar device 1 is input (step ST101). The obtained distance measurement data includes, for example, a moving object such as a preceding vehicle and a stationary object such as a side wall.

Next, the vehicle speed signal from the vehicle speed sensor 3 is input, and the vehicle speed Vf of the own vehicle is calculated (step ST1).
02).

<Detection of Stopping Object Along Curve of Forward Road> It is determined whether or not a group of stopping objects exists from the plurality of objects detected by the radar device 1 (step S).
T120). FIG. 12 shows a more specific operation of step ST120. This processing procedure will be described later.

FIG. 10 is a diagram showing a situation in which the radar apparatus 1 detects a forward object. FIG. 10 (a) shows a curve having a guardrail and a side wall at the shoulder of the road ahead of the vehicle A. Preceding vehicle B trying to enter
Shows a state in which the vehicle is traveling. The triangle protruding ahead of the host vehicle A indicates the horizontal field of view of the radar.

FIG. 10B shows the position coordinates of the object detected by the radar device 1. Among them, a target whose relative speed Vrn is substantially equal to the vehicle speed Vf of the own vehicle,
Treat as a stationary object. The square indicated by reference F1 indicates a stationary object, and the triangle indicated by reference F2 indicates a moving object.
In this embodiment, as shown in the figure, the eight stationary objects F1 along the curve section of the road are recognized by the radar signals reflected on the guardrails and the side walls, and the preceding vehicle B
Has been recognized as a moving object F2.

In step ST121 of FIG. 12, it is determined whether or not the number of detected stationary objects F1 is equal to or greater than a predetermined number.
Here, the minimum number of two required to draw a straight line is a predetermined number. When there are two or more stop objects F1 (step ST1
If it is determined that the object F1 is at a great distance from the stationary object F1 (step ST122), the process proceeds to step ST122. This processing is performed in order to prevent an error in calculating the radius of the curve from increasing when a reflection from an object other than the object along the curve of the road is detected.

After performing the process of removing abnormal values, it is determined whether or not a group of stopped objects F1 remains (step ST123). If it remains (step ST
In order to use the stopped object group for later calculation of the curve radius, the stopped object recognition unit 2g (FIG. 8).
(Refer to step ST124). This is because it has been experimentally confirmed that the stationary objects along the curve are detected so as to be arranged on a straight line substantially tangent to the curve.

On the other hand, when the stop object F1 cannot be detected by the predetermined number or more (NO in step ST121), the stop object F1 is handled as non-detection of the stop object group (step ST12 in FIG. 11).
0).

<Calculation of Curve Radius of Forward Road> Next, a method of calculating a curve radius of a forward road based on an array of stationary objects when a stationary object group is detected will be described with reference to the flowchart of FIG. 9 and 10
Description will be made based on the explanatory diagrams shown in (c) and (d) (step ST300).

First, in the stationary object group, the object S1 (x1, y1) whose X coordinate is the leftmost point when viewed from the host vehicle.
(Step ST301, see FIG. 10C).
Next, the rightmost stationary object S2 in the same group
(X2, y2) is obtained (step ST302). A straight line LS connecting these two points S1 and S2 is set (step ST303, see FIG. 10D). Next, an extension straight line LV with respect to the straight traveling direction of the own vehicle is set (step ST3).
04). Two straight lines LS and LV from the position P0 of the host vehicle
The distance L to the intersection P2 of is obtained (step ST30).
5). The distance L is given by the following equation (3) from two coordinate points.

L = y1-x1 (y2-y1) / (x2-x1) (3) Further, an angle φ at which the straight line LS intersects with the LV is calculated (step ST306). The angle φ is given by the following equation (4) [see FIG. 10 (d)] φ = tan ^-1 {(x2-x1 / (y2-y1)}} (4) Finally, the above is obtained. From the distance L and the angle φ, the curve radius R at the arc P2 is calculated.The angle φ is the angle between the tangent line LS at the point P2 and the straight line LV drawn from the point P2 to the own vehicle position P0. The curve radius R at the point is given by the following equation (5) (see FIG. 9).

R = L / sinφ (5) When the curve radius R is calculated, the process returns to the main processing from step ST300, and the curve radius R is set to the predetermined value 600.
It is determined whether it is larger or smaller than m (step ST10).
4) The entry into the curve section is thereby determined.

<Calculation of Turning Curve Radius of Own Vehicle> On the other hand, in step ST120 (FIG. 11), when a stationary object group is not detected by the radar device 1, the forward curve radius cannot be estimated based on the stationary object arrangement. For this purpose, a turning curve radius R is obtained from the steering angle of the host vehicle (step ST103), and is used to determine whether or not the vehicle is in a curve section.

<Lock-on setting for preceding vehicle>
The subsequent operation (the operation after step ST104 in FIG. 11) is the same as in the first embodiment, and the curve section is determined based on the forward curve radius or the own vehicle turning curve radius obtained from the arrangement of the stationary objects. If a preceding vehicle is present on the own lane when the operation is performed, lock-on is set for the preceding vehicle. Thereafter, the operation is the same as that of the first embodiment.

As described above, in the preceding vehicle following control device according to the third embodiment, even when the own vehicle is still traveling on a straight road, the size of the curve existing in front of the preceding vehicle is large. (Curve radius) can be determined, and when the preceding vehicle starts to enter the curve, the preceding vehicle can be locked on immediately, so that the target vehicle can be stably recognized before approaching the curve section. Can be. Further, even on a road where no partition line is drawn, the road shape can be estimated based on the positional information of the stationary object existing on the road side.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a preceding vehicle following control device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a road shape on which a host vehicle travels and a radar detection state of a preceding vehicle; FIG.
(B) shows the case where the road is curved, and (c) shows the case where the road is S-shaped.

FIG. 3 is a flowchart illustrating an operation of the preceding vehicle following control device according to the first embodiment.

FIG. 4 is a characteristic diagram showing a relationship between a curve radius and a lock-on release delay time.

FIG. 5 is a block diagram showing a configuration of a preceding vehicle following control device according to a second embodiment of the present invention.

FIGS. 6A and 6B are explanatory diagrams when a curve radius of a road ahead is obtained by image processing, wherein FIG. 6A is an original image, FIG. 6B is a plan view image, and FIG. It is.

FIG. 7 is a flowchart showing an operation of the preceding vehicle following control device according to the second embodiment.

FIG. 8 is a block diagram illustrating a configuration of a preceding vehicle following control device according to a third embodiment of the present invention.

FIG. 9 is an explanatory diagram for determining a curve radius ahead of a road based on a front stop object.

FIG. 10 is an explanatory diagram when a curve radius of a road ahead is calculated based on a detection state of a forward object by the radar device and a result of the detection.

FIG. 11 is a flowchart illustrating an operation of the preceding vehicle following control device according to the third embodiment.

FIG. 12 is a flowchart showing step S in the flowchart shown in FIG. 11;
It is a flowchart which shows the process of T120 in detail.

FIG. 13 is a flowchart showing step S in the flowchart shown in FIG. 11;
It is a flowchart which shows the process of T300 in detail.

[Explanation of symbols]

 Reference Signs List 1 radar device 2 target vehicle recognition controller 2a own lane preceding vehicle recognition unit 2b (own vehicle) road shape estimation unit 2c lock-on processing unit 2d target vehicle determination unit 2e image processing unit 2f front vehicle traveling road curve radius estimation unit 2g stationary object Recognition unit 2h Forward road shape estimation unit 3 Vehicle speed sensor 4 Steering angle sensor 5 Inter-vehicle distance control controller

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D044 AA01 AA21 AA25 AA31 AA47 AB01 AC26 AC31 AC56 AC59 AD01 AE04 AE14 AE15 3G093 AA01 BA24 BA27 CB09 DB05 DB16 EA01 EC01 FA03 FA04 FA08 FB05

Claims (6)

[Claims] 1. A preceding vehicle recognizing means for recognizing a preceding vehicle traveling ahead on a traveling lane of the own vehicle, and driving the own vehicle so as to keep a predetermined distance from the recognized preceding vehicle. A preceding vehicle follow-up control device comprising: a traveling shape control means for controlling the vehicle shape; a road shape determining means for determining a curve radius of a road at a traveling position of the own vehicle; and a curve radius determined by the road shape determining means being smaller than a predetermined value. Locks on the preceding vehicle recognized by the preceding vehicle recognizing means as the vehicle to be followed, and thereafter, when the curve radius determined by the road shape determining means becomes a predetermined value or more, the lock on And a lock-on processing means for releasing the following. 2. A preceding vehicle recognizing means for recognizing a preceding vehicle traveling ahead on the traveling lane of the own vehicle, and driving the own vehicle so as to keep a predetermined distance from the recognized preceding vehicle. A preceding vehicle follow-up control device comprising: a traveling shape control means for controlling; a road shape determining means for obtaining a curve radius of a road ahead of the own vehicle; and a curve radius obtained by the road shape determining means being smaller than a predetermined value. If the preceding vehicle recognized by the preceding vehicle recognizing means is locked on as a vehicle to be followed, and the curve radius determined by the road shape determining means becomes a predetermined value or more, the lock on is released. And a lock-on processing means. 3. An image pickup means for picking up an image in front of a traveling road, an image processing means for extracting a partition line from image data picked up by the image pickup means,
The preceding vehicle following control device according to claim 2, further comprising a curve radius estimating means for estimating a curve radius of a road ahead of the vehicle based on the partition line. 4. A stationary object detecting means for detecting a stationary object existing on a road side in front of the own vehicle, a road shape determining means, and a road ahead of the own vehicle based on the detected positional information of the stationary object. 3. The preceding vehicle following control device according to claim 2, further comprising a curve radius estimating means for estimating the curve radius of the preceding vehicle. 5. The lock-on processing unit determines that the curve radius determined by the road shape determination unit is smaller than the predetermined value, and then determines that the curve radius has exceeded a predetermined value. In this case, the lock-on is released after a lapse of a predetermined time after it is determined that the value is equal to or greater than a predetermined value, the preceding vehicle following control apparatus according to any one of claims 1 to 4, wherein . 6. The lock-on processing means, when it is determined that the curve radius determined by the road shape determination means is smaller than the predetermined value, the smaller the curve radius is, the more the curve radius becomes. The preceding vehicle follow-up control device according to claim 5, wherein a time period from when the lock-on is released to when the lock-on is released becomes longer than a predetermined value.