JP3687640B2 - 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]
If the control by such an automatic steering device is described with reference to FIG. 1 (1), it is usually desirable to travel in the center of the lane, so in the case of the above lane detection unit (1) The center position CL of the lane width obtained from the detected left side lane LL and right side lane RL is controlled as the target lane position of the automatic steering device. In the case of the above lane detection unit (2), within the target lane As a position, a marker row is laid at the center position CL of the lane width, and the automatic steering apparatus performs control using this position as the position in the target lane.
[0004]
Therefore, the vehicle 10 on which automatic steering control is performed is controlled so that the vehicle center line CC, which is the center in the left-right direction of the host vehicle, is in a state (state A) that coincides with the in-lane center position CL. That is, when the vehicle center line CC is close to the left segment lane LL as in the state B, the steering in the right direction is automatically performed. Conversely, when the vehicle center line CC is close to the right side lane RL as in state C, the steering to the left is automatically performed.
[0005]
As described above, 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.
[0006]
[Problems to be solved by the invention]
As described above, when the control is always performed with the center in the lane as the target lane position of the automatic steering device, the following problem occurs particularly in the case of a large vehicle.
Fig. 1 (2) shows a case where the vehicle 10 shown in Fig. 1 (1) is a large vehicle, and the vehicle width W2 of the vehicle 10 is wider than the lane width W1 of the lane being traveled. is there. The state corresponding to state A is state D. Thus, when automatic steering control is performed so that the vehicle center line CC, which is the center in the left-right direction of the host vehicle, coincides with the center position CL in the lane, As shown in the state, the left and right sides of the vehicle 10 always protrude to the left and right by the same width from the left and right lane markings LL and RL.
[0007]
When traveling in such a state, there is a risk that a part of the vehicle 10 that protrudes to the road shoulder side will come into contact with a roadside workpiece (a sign, a signboard, etc.). There is also a risk of road shoulder collapse and wheel stripping.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make it possible to travel more safely in a lane that is narrower than the full width of the host vehicle in an automatic steering device that allows the vehicle to travel in a lane.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned purpose, when a large vehicle travels on a narrow road, it is assumed that the left lane marking line LL side is adjacent to the road shoulder in the above state D, for example, as in state E. It is desirable to offset the target lane position to the right by an offset amount q from the width center position CL.
[0009]
From such a viewpoint, the automatic steering apparatus according to the present invention uses a lane marking detection unit that detects a lane marking on the road surface, and lane information based on the lane marking detected by the lane marking detection unit. When the lane width of the lane in which the host vehicle is traveling is narrower than the entire width of the host vehicle and either the left or right side of the traveling lane is closer to the shoulder than the other, the vehicle is offset by a predetermined correction amount in the opposite direction to the shoulder And a calculation unit that determines a position in the target lane and an actuator that performs steering control based on the position in the target lane.
[0010]
That is, in the present invention, the calculation unit determines a target lane position using lane information based on the lane marking detected by the lane marking detection unit, and the lane width of the lane in which the host vehicle is traveling is the full width of the host vehicle. Narrower and the left or right side of the running lane is closer to the shoulder than the other, a predetermined correction amount (for example, a predetermined value is set to one half of the full width of the host vehicle). After adding as a margin, the target lane position is determined by offsetting by a correction amount (subtracted by subtracting one half of the lane width).
[0011]
The actuator also performs steering control based on the target lane position determined by the calculation unit.
Therefore, in the present invention, when the lane width of the running lane is narrower than the entire width of the host vehicle and only one of the left and right sides is adjacent to the road shoulder, the vehicle will not protrude from the road shoulder side. It becomes possible to drive more safely in a lane narrower than the full width of the own vehicle.
[0012]
In this case, when the number of lanes on the running road obtained from the lane information detected by the lane line detection unit is two and the right side of the running lane is It is determined that the road is closer to the shoulder than the left side, and when the vehicle is traveling in the left lane, it may be determined that the left side of the traveling lane is closer to the shoulder than the right side.
[0013]
That is, the calculation unit offsets the position in the target lane as described above only when the number of lanes on the running road is two.
This is because the lane markings are not necessarily set in consideration of the full width of the passing vehicle, but in the case of a lane design of 3 lanes or more, it can be assumed that the lane width is sufficiently secured, This is because it is not necessary to offset the position in the target lane while driving on a road with three or more lanes.
[0014]
In the case of a road with only one lane, both the left and right sides are adjacent to the shoulder. In this case, it is not desirable to offset the position in the target lane to either the left or right, and the center of the lane width is targeted. It is desirable to perform automatic steering control as the position in the lane.
The automatic steering apparatus according to the present invention further includes a marker row detection unit that detects a marker row installed on the road, and the arithmetic unit is configured to detect the marker row while the marker row detection unit is detecting the marker row. The target lane position may be determined giving priority to the marker row.
[0015]
This is because the marker row is usually constructed with the lane width determined in advance assuming the full width of the large vehicle at the time of laying, so when performing automatic steering control by detecting the marker row, This is because it is considered that no offset is required.
[0016]
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 apparatus according to this embodiment includes an automatic steering switch 1, a lane marking detection unit 2, a marker row detection unit 3, a calculation unit 4, and a steering actuator 5.
[0017]
The automatic steering switch 1 is a dedicated switch for the driver to instruct the start and release of automatic steering control by turning the switch ON / OFF.
The lane marking detection unit 2 and the marker row detection unit 3 output information on the relative position of the lane detected with reference to the own vehicle, and each includes a combination of a camera and an image processing device, a lane marker sensor, What is necessary is just to use the known thing which can be comprised by the combination with a signal processing apparatus.
[0018]
The calculation unit 4 includes an input unit 41 that reads an automatic steering switch signal from the automatic steering switch 1, lane information from the lane marking detection unit 2, and lane information from the marker row detection unit 3, and an output of the input unit 41. CPU 42 that performs calculation / judgment regarding automatic steering control using signals, RAM 43 used by CPU 42 for calculation, ROM 44 for storing control programs and control parameters, and steering actuator 6 according to output data obtained by CPU 42 Output unit 45, and a power source unit 46 for supplying necessary power to each of these units from a vehicle power source.
[0019]
The steering actuator 5 may be a well-known device that automatically operates the steering wheel (not shown) of the vehicle by the output from the output unit 45.
FIG. 3 shows the flow of the control program stored in the ROM 44 in the arithmetic unit 4 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.
[0020]
In addition, all the positions used in this flowchart are represented by “0” as the center line in the lateral direction of the host vehicle, + on the right side of the vehicle, and − on the left side of the vehicle. It is assumed that the lane marking detection unit 2 and the marker row detection unit 3 also express the lane information with the center line in the left-right direction of the host vehicle being “0”.
[0021]
First, the CPU 42 reads the automatic steering switch signal from the automatic steering switch 1, the lane information from the lane marking detection unit 2, and the lane information from the marker row detection unit 3 via the input unit 41 (step S1).
Next, the CPU 42 confirms ON / OFF of the automatic steering switch 1 based on the automatic steering switch signal read in step S1 (S2). When the automatic steering switch 1 is OFF, automatic steering control is not performed, and therefore the steering actuator 5 is set to no steering control (S3), and the process is terminated.
[0022]
When the automatic steering switch 1 is ON in step S2, the CPU 42 determines the presence / absence of the marker row based on the lane information from the marker row detection unit 3 read in step S1 (S4). If there is a marker row in step S4, the lane width center position is calculated based on the lane information (marker row) from the marker row detector 3 (S5). In this case, the position of the marker row is directly used as the lane width center position, and “0” is substituted for the offset amount (S6).
[0023]
If there is no marker row in the above step S4, the lane width is calculated (S7) based on the lane information from the lane marking detection unit read in Step S1, and then the lane width center position is calculated (S8). ). In this case, the center of the left segment lane and the right segment lane may be calculated as the lane width center position.
[0024]
Next, the lane width obtained in step S7 is compared with the set value T1 corresponding to the entire width of the host vehicle (S9). If the lane width is smaller than the set value T1, the lane classification read in step S1 The number of lanes is calculated based on the lane information from the line detection unit 2 (S11).
If the number of lanes is 2 in step S11 described above, a deviation which is an absolute value of the left and right offset amounts is obtained (S12). In this case, a preset value T2 is determined in advance to give a certain margin on the shoulder side of the road, and the lane width 2 is calculated from the value obtained by adding the preset value T2 to one half of the preset value T1 corresponding to the full width of the host vehicle. The value obtained by subtracting 1 / min is the deviation.
[0025]
Next, it is determined whether the running lane is the right side or the left side of the two lanes (S13) .If the lane is on the right side, in order to offset to the left side, the sign of the deviation obtained in step S12 is reversed. Substitute in the offset amount (S14). Conversely, if it is on the left side, it is offset to the right side, so the deviation obtained in step S12 is directly substituted for the offset amount (S15).
[0026]
When the lane width ≧ the set value T1 in step S9 and when the number of lanes ≠ 2 in step S11, “0” is substituted for the offset amount (S15).
After obtaining the offset amount by any one of steps S6, S14, and S15, the CPU 42 adds the offset amount to the lane width center position calculated in step S5 or S8, and calculates the target lane position (step S16).
[0027]
Since the target lane position obtained in step S16 is based on the center line in the left-right direction of the host vehicle, it is as follows.
(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 left side of the center line in the lateral direction of the vehicle.
[0028]
(c) Target lane position> 0: The target lane position is on the right side of the center line in the lateral direction of the vehicle.
It is determined whether the target lane position determined in this way corresponds to any of the above cases (step S17).
[0029]
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 5 is controlled to be neutrally held in step S18.
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, so the steering actuator 5 is steered to the left in step S19.
[0030]
Further, when the position in the target lane> 0 (c), the target lane position is on the right side of the center line in the left-right direction of the host vehicle, so in step S20, the steering actuator 5 is turned to the right.
[0031]
【The invention's effect】
As described above, according to the automatic steering apparatus of the present invention, the calculation unit uses the lane information based on the lane marking detected by the lane marking detection unit, and the lane width of the lane in which the host vehicle is traveling. Is narrower than the full width of the host vehicle and the left or right side of the running lane is closer to the shoulder than the other, the target lane position is determined by offset by a predetermined correction amount in the opposite direction to the road shoulder, Since the steering actuator is controlled to be steered based on the target lane position, it becomes possible to travel more safely in a lane narrower than the full width of the host vehicle.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a target lane position in automatic steering control;
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 Automatic steering switch
2 Lane marking detector
3 Marker row detector
4 Calculation unit
5 In the steering actuator diagrams, the same reference numerals indicate the same or corresponding parts.

Claims (4)

A lane marking detection unit for detecting a lane marking on the road surface;
Using the lane information based on the lane line detected by the lane line detection unit, the lane width of the lane in which the host vehicle is traveling is narrower than the entire width of the host vehicle, and A calculation unit that determines a target lane position by offsetting by a predetermined correction amount in a direction opposite to the road shoulder when closer to the road shoulder than the other;
An actuator for performing steering control based on the target lane position;
An automatic steering apparatus comprising: In claim 1,
The calculation unit has two lanes of a road that is obtained from the lane information detected by the lane marking detection unit, and when the vehicle is driving in the right lane, only the right side of the driving lane is An automatic steering apparatus characterized by determining that the vehicle is adjacent to a road shoulder and determining that only the left side of the traveling lane is adjacent to the road shoulder when the vehicle is traveling in the left lane. In claim 1,
A marker row detector for detecting a marker row installed on the road;
An automatic steering device characterized in that, while the marker row detection unit detects the marker row, the calculation unit prioritizes the marker row and determines the target lane position. In claim 1,
The calculation unit adds a predetermined value as a margin to half of the entire width of the host vehicle, and then calculates the predetermined correction amount by subtracting one half of the lane width. Steering device.

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