JP3873658B2 - Automatic steering device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic steering device, and more particularly, to an automatic steering device for a vehicle to perform lane-holding travel.
[0002]
[Prior art]
Such an automatic steering apparatus is provided with a lane detection unit that detects a lane in which the host vehicle travels. As this lane detection unit, (1) one that visually detects a segmented lane using a camera or the like, and (2) a marker row comprising magnets and radio wave transmitters is laid in the lane, and this marker row is used as a magnetic sensor. And those detected by a radio antenna are generally known.
[0003]
Usually, it is considered desirable to travel in the center of the lane, so in the case of the above lane detection unit (1), the center of the lane width is controlled as the target lane position of the automatic steering device, In the case of the lane detection unit {circle around (2)}, the marker row is laid in the center of the lane width as the target lane position, and the automatic steering device performs control using this as the target lane position.
[0004]
As a result, in either case of the lane detection units {circle around (1)} and {circle around (2)}, the center of the lane width is controlled as the target lane position of the automatic steering device.
[0005]
[Problems to be solved by the invention]
As described above, if control is always performed with the center in the lane as the target lane position of the automatic steering device, the problem shown in FIG. 1 (1) occurs.
In other words, the lane detection unit 1 is normally installed at the center position of the front portion of the vehicle 10, and as described above, control is performed by the automatic steering device so that the lane detection unit 1 matches the lane width center position CL. However, since the automatic steering control is performed without considering the inner wheel difference, the rear part of the vehicle 10 protrudes from the left side lane (inner lane) LL on the curved road as shown in the figure.
[0006]
Since this problem occurs in a vehicle having a long wheel base, it becomes a serious problem particularly in a large vehicle.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to control an automatic steering device for carrying a vehicle in a lane so that the rear side of the vehicle does not protrude from an inner lane during running on a curved road.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an automatic steering apparatus according to the present invention obtains a lane width center position from a lane detection unit, a curve road detection unit, a lane detected by the lane detection unit, and the curve road detection unit. A calculation unit for determining a position in the target lane of the vehicle by obtaining an offset direction and an offset amount of the vehicle with respect to the center position of the lane width according to the direction of the curved road and the radius of curvature detected by And an actuator that performs steering control based on the position.
[0008]
That it is, in the present invention, the arithmetic unit calculates a relative position between the lane and the vehicle detected by the lane detecting unit. At the same time, the calculation unit obtains the offset direction and the offset amount for correction according to the direction and the radius of curvature of the curved road detected by the curved road detection unit.
[0009]
Further, the calculation unit corrects the relative position based on the offset direction and the offset amount thus determined, and sets this as the target lane position.
The actuator performs steering control based on the target lane position determined by the calculation unit.
[0010]
In this case, the lane detection unit may be a single unit that also serves as a curved road detection unit. Further, the calculation unit can increase the offset amount as the curvature radius is smaller.
Thus, in the present invention, the target lane position for automatic steering on a curved road corresponds to the curved road. For example, when traveling on a right curved road, the target lane position is corrected to the left by the offset amount, and the left curved road In the case of traveling, the target lane position is corrected to the right by the offset amount.
[0011]
Therefore, as shown in FIG. 1 (2), for example, when the front center position of the vehicle 10 in which the lane detector 1 is installed is set as the vehicle reference position, the vehicle reference position is the relative lane width center. The offset amount q is offset from the position CL or the segmented lane position, thereby avoiding a state where the rear portion of the vehicle 10 protrudes from the left lane LL.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 shows a configuration of an embodiment of an automatic steering apparatus according to the present invention. The automatic steering device according to this embodiment includes a lane detector 1, a curve road detector 2, a calculator 3, and a steering actuator 4.
[0013]
The lane detection unit 1 outputs information on the relative position of the lane detected with reference to the own vehicle, and is configured by a combination of a camera and an image processing device, a combination of a lane marker / sensor and a signal processing device, or the like. A known one that can be used may be used.
[0014]
The curved road detection unit 2 is, for example, a combination of a camera and an image processing device (which can also be used as the lane detection unit 1), a vehicle yaw rate sensor, a device that receives and obtains curved road information from the road infrastructure side, A well-known device such as a navigation device that obtains curve road information from GPS and map information can be used.
[0015]
The calculation unit 3 uses the input unit 31 that reads the lane information from the lane detection unit 1 and the curve road information from the curve road detection unit 2, and uses the output signal of the input unit 31 to calculate and judge the automatic steering control. The CPU 32 to perform, the RAM 33 used by the CPU 32 for operations, the ROM 34 for storing control programs and control parameters, the output unit 35 for driving the steering actuator 4 according to the output data obtained by the CPU 32, and the vehicle power supply And a power source unit 36 for supplying necessary power to each unit.
[0016]
The steering actuator 4 may be a known device that automatically operates the steering wheel (not shown) of the vehicle by the output from the output unit 35.
FIG. 3 shows the flow of the control program stored in the ROM 34 in the arithmetic unit 3 shown in FIG. 2, and the operation of the embodiment of FIG. 2 will be described below with reference to FIG. Note that this flowchart is started at predetermined time intervals, and only the part related to the control of the control device is described, but initial processing at the time of starting up the hardware such as the CPU is omitted.
[0017]
First, the CPU 32 reads the lane information of the lane detection unit 1 and the curve road information of the curve road detection unit 2 via the input unit 31 (step S1). In this case, the lane information from the lane detector 1 is information on the relative position of the lane detected with reference to the center line in the left-right direction of the host vehicle (in the case of segmented lane detection, the position information of the segmented lanes on the left and right, In the case of detection, this is the marker row position information). The curved road information of the curved road detection unit 2 is information related to the curved road direction and the radius of curvature of the traveling road.
[0018]
Next, the CPU 32 calculates the lane width center position based on the lane information read in step S1. In this case, if the lane information of the lane detector 1 is segment lane information, the center of the left segment lane LL and the right segment lane RL (see Fig. 1) is the lane width center position CL as shown in FIG. When the marker row information is used, the marker row position is usually used as the lane width center position CL as it is.
[0019]
Next, the curve direction is determined from the curve road information (step S3). If the road is a left curve road, the process proceeds to step S4, and if the road is a right curve road, the process proceeds to step S5 to obtain the left and right offset amounts q.
The offset amount q can be calculated geometrically from the vehicle wheelbase, the tread, and the curve curvature radius r, and a value stored in advance in the ROM 34 may be read using the curve curvature radius r as a parameter.
[0020]
The curve curvature radius r can be obtained as follows.
(1) When a combination of a camera and an image processing device is used as the lane detection unit 1, since the front division lane is detected by the camera, it is obtained from the detected division lane.
[0021]
(2) When the lane detection unit 1 uses a combination of a lane marker sensor for detecting a marker row and a signal processing device, the curve curvature radius r is set as described above by the separately provided curve road detection unit 2 What is necessary is just to detect.
The offset amount q with respect to the curve curvature radius r is set so that the offset amount q increases as the curvature radius r decreases.
[0022]
In this way, the target lane position can be determined by adding the offset amount q obtained in steps S4 and S5 to the lane width center position CL calculated in step S2 (step S6).
In addition, the offset amount obtained for the left curve road in step S4 acts to move the target lane position to the right side, and in the case of the right curve road shown in step S5, the target lane position is set to the left side. Since the position in the target lane obtained in step S6 is based on the center line in the left-right direction of the host vehicle, the position is as follows.
[0023]
(a) Target lane position = 0: The target lane position is on the center line in the lateral direction of the host vehicle.
(b) Target lane position> 0: The target lane position is on the right side of the center line in the lateral direction of the vehicle.
(c) Target lane position <0: The target lane position is on the left side of the center line in the left-right direction of the vehicle.
[0024]
It is determined whether the target lane position determined in this way corresponds to any of the above cases (step S7).
That is, when the target lane position = 0 (a), since the target lane position exists on the center line in the left-right direction of the host vehicle, the steering actuator 4 is controlled to be neutrally held in step S8.
[0025]
When the target lane position <0 (b), the target lane position is on the left side of the center line in the left-right direction of the host vehicle, and therefore, the steering actuator 4 is steered to the left in step S9.
Further, when the position in the target lane> 0 (c), the position in the target lane is on the right side of the center line in the left-right direction of the host vehicle, so the steering actuator 4 is subjected to the right turning control in step S10.
[0026]
In the above embodiment, the offset amount q is added to the lane width center position CL. However, since the position of the own vehicle and the position of the lane are relative positions, the lane is used as a reference (segment lane position or lane width center. Even if the specific position of the own vehicle is relatively obtained as the position) and the offset amount is added to this, the same operation as described above can be realized.
[0027]
【The invention's effect】
As described above, according to the automatic steering device of the present invention, the relative position between the lane detected by the lane detection unit and the vehicle is obtained, and the curved road detected by the lane detection unit or the curved road detection unit. The calculation unit determines the target lane position of the relative position based on the offset direction and the amount determined according to the direction and the radius of curvature, and controls the steering actuator. It is possible to avoid a situation in which the vehicle protrudes, and thus the vehicle can be operated safely.
[Brief description of the drawings]
FIG. 1 is a schematic plan view for explaining operational differences between an automatic steering apparatus according to the present invention and a conventional technique.
FIG. 2 is a block diagram showing an embodiment of an automatic steering apparatus according to the present invention.
FIG. 3 is a flowchart showing a control program used in the embodiment of the automatic steering apparatus according to the present invention shown in FIG. 2;
[Explanation of symbols]
1 Lane detector
2 Curved road detector
3 Calculation unit
4 Steering actuator
10 vehicles
CL lane width center position
RL right side lane
In the left side lane map, the same reference numerals indicate the same or corresponding parts.

Claims (4)

A lane detector;
A curved road detection unit;
The center position of the lane width is obtained from the lane detected by the lane detector, and the offset direction and the offset amount of the vehicle with respect to the center position of the lane width according to the direction and the radius of curvature of the curve road detected by the curve road detector. Calculating a position in the target lane of the vehicle by obtaining
An actuator for performing steering control based on the target lane position;
An automatic steering apparatus comprising: In claim 1,
An automatic steering apparatus, wherein the lane detection unit is a single unit that also serves as the curve road detection unit. In claim 1,
The automatic steering device, wherein the calculation unit increases the correction offset amount as the curvature radius is smaller. In any one of Claim 1 to 3,
The lane is a lane marker or an automatic steering apparatus, wherein the marker sequence der Rukoto.

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