JPH09292919A - Travel controller for automatic travel vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always provide the same detection precision with a simple control method and to improve the travel control performance by obtaining deviations in the direction of vehicle width between travel route reference lines on a travel route and plural notice points on a virtual straight line showing the travel direction of a vehicle. SOLUTION: An image pickup camera 3 which image-picks up an image in front of the vehicle on the travel route 2 is fitted to a golf car 1 as an automatic travel vehicle traveling on the travel route 2 where the travel route reference lines 2a and 2b are plotted with the virtual straight line A showing the travel direction as a center. A controller 5 controlling the automatic travel of the golf car 1 detects the travel route reference lines 2a and 2b provided on the travel route 2 from the image from the image pickup camera 3 and operates the deviations D between the travel route reference lines 2a and 2b in plural notice point distances K on the virtual straight line A. A target vehicle speed V is set based on change amounts (absolute value of differences) between the respective operated deviations D and travel speed is controlled so that it becomes target speed V.

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 an automatic traveling vehicle which detects a traveling road reference line on a traveling road by a camera or the like installed in the vehicle and automatically travels based on the reference line.

[0002]

2. Description of the Related Art Conventionally, as an automatic traveling vehicle that automatically travels based on a road reference line such as a white line in front of the vehicle, a storage device for storing white line information detected by a sensor and a vehicle front based on the stored past white line information. The vehicle speed control device controls the traveling speed of the vehicle to be low when the deviation is large according to the deviation between the road white line information detected by the sensor and the estimated linear There is such a method (see Japanese Patent Laid-Open No. 4-306709).

[0003]

However, in the conventional vehicle which controls the traveling speed based on the difference between the estimated value of the road alignment and the actual measured value, for example, when traveling on a curve, the above estimation is performed as the traveling speed increases. Since there is a possibility that the difference between the measured value and the actual measured value becomes large, there is a problem that the vehicle speed cannot be increased so much.

Further, since the image processing apparatus detects white line information at a plurality of positions, there is a problem that the total processing time becomes long and it becomes difficult to control speed quickly according to the road alignment.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to always perform control with the same accuracy regardless of whether the vehicle speed is high or low, and to perform speed control in accordance with the road alignment. An object of the present invention is to provide a traveling control device for an autonomous vehicle that can perform the above.

[0006]

As shown in FIG. 9, the invention of claim 1 is a detection means 50 for detecting a track reference line provided on a track, and the detected track reference line and a vehicle. Deviation amount calculation means 51 for obtaining each deviation in the vehicle width direction from a plurality of gaze points on a virtual straight line indicating the traveling direction, and target vehicle speed setting means 52 for setting a target vehicle speed based on the change of each deviation thus obtained. And a traveling speed control means 53 for controlling the traveling speed so that the target vehicle speed is set as described above.

According to a second aspect of the present invention, in the first aspect, the deviation amount calculating means 51 and the target vehicle speed setting means 52 are:
When the amount of change between the deviations is smaller than a predetermined value, the gazing point is moved away from the own vehicle and the target vehicle speed is increased, while when the amount of change between the deviations is larger than a predetermined value, the gazing point is It is characterized in that the target vehicle speed is reduced while bringing the vehicle closer to the own vehicle.

According to a third aspect of the present invention, in the first or second aspect, the gazing point is forward from the host vehicle by a braking distance required to decelerate from a predetermined target vehicle speed to a predetermined minimum speed with a predetermined minimum deceleration. It is characterized by being located at.

According to a fourth aspect of the present invention, in the third aspect, the deviation amount calculating means 51 obtains the first and second deviations of the first gazing point and the second gazing point located in front of the first gazing point, and the target is obtained. When the change amount between the first and second deviations is smaller than a predetermined value, the speed calculation means sets the second target vehicle speed corresponding to the second gazing point as the target vehicle speed, and when the change amount is larger than the predetermined value. Is characterized in that the first target vehicle speed corresponding to the first gazing point is set as the target vehicle speed.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the target vehicle speed setting means 52 obtains the target vehicle speed obtained in the current control cycle in the control cycle within the immediately preceding predetermined time. If the target vehicle speed is not within the range between the minimum value and the maximum value, the target vehicle speed obtained in the current control cycle is adopted, and if it is in the above range, the target speed obtained in the previous control cycle is adopted. It is characterized by that.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 8 are views for explaining a traveling control device for an automatic traveling golf car according to an embodiment of the present invention, FIG. 1 is a schematic diagram for explaining traveling control, and FIG. 2 is an image captured by an imaging camera. The image shown,
FIG. 3 is a block configuration diagram showing the configuration of the traveling control device,
4 and 5 are flowcharts for explaining the operation of the traveling control device, and FIGS. 6 to 8 are diagrams showing the processing contents in each cycle processing mode of the traveling control device.

In FIG. 1, reference numeral 1 indicates a golf car as an automatic vehicle that travels on a road (running road) 2 on which white lines (running road reference lines) 2a and 2b are drawn. Is a virtual straight line indicating the direction of travel (imaging center line)
An image pickup camera 3 for picking up an image in front of the vehicle on the road 2 centering on A is attached.

Ki (i = 1, 2, ..., N) is the distance from the camera 3 to each front gazing point, and Di (i = 1, 1)
2, ..., N) are deviations (distances) in the vehicle width direction from the virtual straight line A to the road reference line 2a or 2b at each front gazing point distance Ki. In this specification, for convenience, the above K
In some cases, i may be used as each forward gazing point.

Here, the distance Ki to the front gazing point is set by the following method. That is, the minimum speed V1
In order to set a total of n-1 target vehicle speed options between the maximum vehicle speed Vn and the maximum speed Vn that can be driven by automatic driving, and to decelerate from each option speed (V2 to Vn) to the above V1 with the minimum deceleration. The required braking distance is the distance (K1 to Kn-1) to the front gazing point.

In other words, K1 is the distance from the target vehicle speed V2 to the gazing point located in front of the vehicle by the distance required to decelerate from the target vehicle speed V2 to the minimum speed V1 with the minimum deceleration, and K2 is the target vehicle speed. It is a distance from V3 to the gazing point located in front of the vehicle by a distance required to decelerate from V3 to the minimum speed V1 with the minimum deceleration, and is set farther from K1.

The minimum speed V1 is the maximum speed within the range where the riding feeling is not impaired when the golf car 1 turns with the minimum turning radius. 1 is, for example, 3 km / h
r. The maximum speed Vn is, for example, 20 km.
/ Hr. The minimum deceleration is the maximum deceleration within a range that does not impair the riding feeling. The minimum speed and the minimum deceleration may be set by a method other than the above.

In the present embodiment, in determining the target vehicle speed, a total of n-1 processing modes from the first cycle processing mode to the (n-1) th cycle processing mode are introduced, and in each cycle processing mode. , The first and second gazing point distances Kc and Kc + 1 and the first and second target velocities Vc and Vc + 1 are set, and one of them is selected.

The image pickup camera 3, as shown in FIG.
Via the I / F 4, it is connected to a controller 5 for controlling the automatic running of the golf car 1, and the controller 5 is provided with a vehicle speed sensor 6 for detecting a vehicle speed, a drive motor (starter), and an engine throttle. A controller 7 such as a driving motor is connected via I / Fs 8 and 9, and a traveling control device 19 for controlling the traveling speed of the golf car 1 based on the information from the imaging camera 3 and the vehicle speed sensor 6. Is configured.

The controller 5 uses the image from the image pickup camera 3 to determine the runway reference line 2a provided on the runway,
As the detection means for detecting 2b, the calculated deviations as deviation amount calculation means for calculating the deviation D between the plurality of gazing point distances K on the virtual straight line A and the detected track reference lines 2a, 2b. It functions as a target vehicle speed setting means for setting the target vehicle speed V based on the amount of change (absolute value of the difference) between D and as a traveling speed control means for controlling the traveling speed so that the target vehicle speed V is set.

Further, the controller 5 functions as the deviation amount calculating means and the target vehicle speed setting means,
When the amount of change between the deviations D is smaller than a predetermined value, the gazing point to be subjected to the deviation calculation is moved away from the own vehicle and the target vehicle speed V is increased, while when the amount of change of the deviation D is larger than a predetermined value. Reduces the target vehicle speed V while bringing the target gazing point closer to the own vehicle.

In the function as the deviation amount calculating means, the controller 5 moves the gazing point from the target vehicle speed to a predetermined minimum speed (a range in which the riding feeling is not impaired in the turning traveling at the minimum turning radius). The maximum vehicle speed set in 1.) and a predetermined minimum deceleration (maximum deceleration set in the range that does not impair the riding feeling) to reduce the braking distance. The viewpoint and the second gazing point located a predetermined distance ahead of the first gazing point are adopted as the deviation calculation targets.

Furthermore, the controller 5 functions as the deviation amount calculating means and the target speed calculating means, and based on the first and second gaze points, the first and second deviations and the first and second deviations. 2 The target vehicle speed is obtained, and when the amount of change between the first and second deviations is smaller than the predetermined value, the larger one of the first and second target vehicle speeds is set as the target vehicle speed, and the amount of change is larger than the predetermined value. At this time, the smaller one of the first and second target vehicle speeds is set as the target vehicle speed.

Further, the controller 5 functions as the target vehicle speed setting means, and the target vehicle speed obtained in the current control cycle (current cycle processing mode) is
If the target vehicle speed obtained in the control cycle (past cycle processing mode) within the immediately preceding predetermined time is not within the range between the minimum and maximum values, the target vehicle speed obtained in the current control cycle is adopted, If it is within the range, the target speed obtained in the previous control cycle is adopted.

The controller 5 is specifically provided with an image processing unit 10 for image-processing the data imaged by the camera 3, and the image processing unit 10 has the road 2
A reference line detection unit (detection means) 17 for detecting the upper white line 2a as a road reference line, and a detection possibility determination unit 18 for determining whether or not the reference line is properly detected.

Further, based on the image data, the controller 5 deviates from the white line (track reference line) 2a and the virtual straight line (image center line) A at the gazing point which is a predetermined distance Ki forward from the vehicle. A deviation amount calculation unit (deviation amount calculation means) 11 that calculates Di, whether the vehicle speed is appropriate based on the calculated change amount of the deviation, and whether the curvature of the road is within a predetermined range, that is, , A road suitability judgment unit 12 for judging whether or not the front road is a curve that makes a sharp turning motion that impairs the feeling of getting on when the vehicle travels at the current target vehicle speed, and the following based on the deviation amount calculated above: A provisional target vehicle speed determination unit 13 that determines the processing mode of the cycle and the provisional target vehicle speed, a final target vehicle speed determination unit (target vehicle speed setting means) 14 that determines the final target vehicle speed, and the determined target vehicle speed. A driving force calculation unit 15 for calculating a required driving force based on the driving force; and a command signal output unit (running speed control means) 16 for outputting a command signal for controlling a motor controller or the like based on the calculated driving force. ing.

Next, the vehicle speed control operation by the controller 5 will be described. When the image of the road ahead of the vehicle (see FIG. 2) captured by the image capturing camera 3 is input (step S1), the road reference line (white line 2a) is detected based on the input image data ( Step S2), if the track reference line is properly detected (Step S3),
Distances (Kc, Kc + 1) to the first and second forward gazing points in the current processing cycle set in step S21 of FIG.
) Between the white line 2a and the image center line A (D
c, Dc + 1) is calculated (step S4).

When it is determined that the road is appropriate in view of the absolute value of the difference between the deviations (Dc, Dc + 1), the relationship between the current vehicle speed and the curvature of the road (step S5), the processing in the next cycle is performed. As the mode, a value obtained by adding “1” to the current processing mode is also used as the provisional target vehicle speed in the current cycle, and the option (V
The larger one (c, Vc + 1) (Vc + 1) is set (step S6). In this case, c is 1 to
It will change between n-1.

When the runway reference line is not properly detected in the step S3, or when the step S5 is executed.
When it is determined that the road is not appropriate in, the process mode in the next cycle is the current process mode minus "1", and the temporary target vehicle speed in the current cycle is the smaller one of the above options ( Vc) is set (step S7).

Next, as a noise removal process due to a temporary erroneous detection or the like, the provisional target vehicle speed set above is the minimum and maximum target vehicle speeds determined in the processing cycle at the immediately preceding preset time. It is determined whether or not it is within the range between and, and if it is within this range, the provisional target vehicle speed is determined as the final target vehicle speed (step S
8, S9).

Then, the required driving force is calculated based on the final target vehicle speed and the current vehicle speed thus determined (step S10), and a predetermined command signal is sent to the controller 7 such as the drive motor and the engine throttle motor. It is output (step S11).

Now, the setting of the target vehicle speed and the next cycle processing mode will be described more concretely with reference to FIGS. 6 to 8.

First, in the current cycle processing mode c, both (deviations Dc, Dc + 1) at the distances (Kc, Kc + 1) to the first and second forward gazing points are properly detected, and the deviations (both deviation points) between the gazing points ( If the absolute value of the difference of Dc, Dc + 1) is smaller than a predetermined threshold value, the larger one (Vc + 1) from the above options (Vc, Vc + 1)
Is selected as the target vehicle speed and the "current cycle processing mode +
1 ”is set as the next cycle processing mode.

Then, in the (c + 1) th cycle processing mode, the distance (Kc + 1,
The deviations (Dc + 1, Dc + 2) in Kc + 2) are both properly detected, and the deviations (Dc
When the absolute value of the difference between +1 and Dc + 2) is smaller than a predetermined threshold value, the larger one (Vc + 1) from the above options (Vc + 1, Vc + 2) is selected as the target vehicle speed, and "current cycle processing mode +1" is selected. Is set as the next cycle processing mode.

Specifically, the current cycle processing mode (c)
= 1, when the detection of the first deviation D1 of the first forward gazing distance K1 fails, when the detection of the first deviation D1 succeeds and the detection of the second deviation D2 fails, and Deviation D1,
The detection of D2 is successful and the first and second of K1 and K2 are performed.
When the absolute value (| D1-D2 |) of the difference between the deviations is larger than the predetermined threshold value, the target vehicle speed = V1, the next processing mode = 1
Is set to On the other hand, the deviations at both the gazing point distances K1 and K2 have been successfully detected, and the absolute value (| D1-D2 |)
Is smaller than the predetermined threshold value, the target vehicle speed = V2, the next processing mode = 2 is set, and the processing mode of the second cycle is entered.

Second cycle processing mode (c) =
2, when the deviation of the second front gazing point distance K2 is unsuccessful, when the deviation of the second front gazing point distance K2 is successfully detected and the deviation of the third front gazing point distance K3 is unsuccessful,
When the deviation between the two gazing point distances K2 and K3 is successfully detected and the absolute value (| D2-D3 |) of the difference between the second and third deviations in K2 and K3 is larger than the predetermined threshold value, ,
The target vehicle speed = V2, the next processing mode = 1 is set, and the processing of the first cycle is performed again. On the other hand, when the deviation between the two gazing point distances K2 and K3 is successfully detected and the absolute value (| D2-D3 |) is smaller than a predetermined threshold value,
The target vehicle speed = V3 and the next processing mode = 3 are set, and the processing mode of the third cycle is entered.

Similarly, in the processing mode (c) = n-2, when the deviation of the n-2th forward gazing point distance Kn-2 fails to be detected, the deviation of the n-2th forward gazing point distance Kn-2 is detected. Is successfully detected and the deviation of the (n-1) th forward gazing point distance Kn-1 is unsuccessful, and both the gazing point distances Kn-2, K are detected.
The detection of the deviation of (n-1) is successful, and the absolute value of the difference between the deviations of (n-2) th and (n-1) th in Kn-2 and Kn-1 (| (Dn
-2)-(Dn-1) |) is larger than a predetermined threshold value, the target vehicle speed = Vn-2, the next processing mode = n-3 is set, and the processing of the n-3th cycle is performed. Will be done again.
On the other hand, the deviation between the two gazing point distances Kn-2 and Kn-1 has been successfully detected, and the absolute value (| (Dn-2)-(Dn-
1) When |) is smaller than a predetermined threshold value, the target vehicle speed =
Vn−1, next processing mode = n−1, set to nth
-1 Proceed to cycle processing.

Furthermore, in the processing mode (c) = n-1, when the detection of the deviation of the (n-1) th forward gazing point distance Kn-1 fails, the deviation of the (n-1) th forward gazing point distance Kn-1. Is successfully detected and the deviation of the n-th forward gazing point distance Kn is unsuccessful, and the deviation of both the gazing point distances Kn-1, Kn is successful and the n-th point of Kn-1, Kn is detected. −
1, absolute value of the difference between the nth deviations (| (Dn-1) -Dn |)
Is greater than a predetermined threshold value, the target vehicle speed = Vn−
1, the next processing mode = n-2 is set, and the processing of the (n-2) th cycle is performed again. On the other hand, when the deviation between the two gazing point distances Kn-1 and Kn is successfully detected and the absolute value (| (Dn-1) -Dn |) is smaller than a predetermined threshold value, the target vehicle speed = Vn, The next processing mode = n-1 is set, and the processing of the (n-1) th cycle is repeated.

In this way, the target speed of the vehicle is set based on the amount of change in the deviation between the white line of the road (runway reference line) and the virtual straight line indicating the traveling direction, and the running speed is controlled based on this target speed. As compared with the conventional one that controls the traveling speed based on the difference between the estimated value of the road alignment and the actual measured value, the same detection accuracy is always obtained while adopting a simple control method. Therefore, the traveling control performance can be improved.

Further, since the point of interest in front of the vehicle is the gazing point for the braking distance required for decelerating from the target speed to the minimum speed with the minimum deceleration that does not impair the riding feeling, the minimum speed may occur due to an abnormal detection of the gazing point or the like. When it becomes necessary to decelerate to, it is possible to decelerate to the minimum speed without impairing the riding feeling.

Further, a point in front of the vehicle by the braking distance required to decelerate from the target speed to the minimum speed with the minimum deceleration is set as the first gazing point, and the second gazing point is separated from the first gazing point by a predetermined distance. Since the deviation is calculated from the gazing point, the time required for speed control can be shortened and the vehicle speed can be quickly controlled according to the track alignment.

Since the target vehicle speed is made to correspond to the gazing point, the speed control can be simplified and the time required for the control can be shortened.

When the target vehicle speed set by the current control cycle is within the range between the maximum value and the minimum value of the target vehicle speed in the past control cycle in the immediately preceding predetermined time, the previous control cycle is executed. Since the target vehicle speed is adopted, it is possible to prevent the speed from changing excessively due to a primary erroneous detection or the like, and the riding feeling can be improved also from this point.

In the above embodiment, a golf car has been described as an example, but the present invention can of course be applied to automated vehicles other than golf cars.

[0044]

As described above, according to the traveling control device for an autonomous vehicle according to the invention of claim 1, a plurality of injection lines on a virtual straight line indicating the traveling direction of the vehicle and the traveling road reference line provided on the traveling road. Since the deviation in the vehicle width direction from the viewpoint is obtained and the target vehicle speed is set based on the change of each deviation, the control of the traveling speed is performed based on the difference between the estimated value of the conventional road alignment and the measured value. The problem that the difference between the estimated value and the actually measured value becomes large can be avoided, and the same detection accuracy can always be obtained while adopting a simple control method, and the traveling control performance can be improved.

According to the second aspect of the present invention, when the variation amount of the deviation is smaller than the predetermined value, the gazing point is moved away from the own vehicle and the target vehicle speed is increased, while the variation amount of the deviation is less than the predetermined value. When it is large, the gazing point is brought closer to the own vehicle and the target vehicle speed is reduced, so that the target vehicle speed selection control is simple and the control time can be shortened.

According to the third aspect of the invention,
Since the point is located ahead of the host vehicle by the braking distance required to decelerate from the target vehicle speed to the predetermined minimum speed with the predetermined minimum deceleration, it is necessary to decelerate to the minimum speed due to detection abnormality of the gazing point or the like. In this case, there is an effect that the vehicle can be decelerated to the minimum speed before the vehicle reaches the gazing point and without impairing the riding feeling.

According to the fourth aspect of the present invention, the first and second deviations and the first and second target vehicle speeds are obtained based on the first and second fixation points, and the change amount between the first and second deviations is calculated. Is smaller than a predetermined value, the larger one of the first and second target vehicle speeds is set as the target vehicle speed, and when the change amount is larger than the predetermined value,
Since the smaller one of the second target vehicle speeds is set as the target vehicle speed, the target vehicle speed selection control is easy and the control time can be further shortened.

According to the fifth aspect of the present invention, the target vehicle speed obtained in the current control cycle is not within the range between the minimum value and the maximum value of the target vehicle speeds obtained in the control cycle in the immediately preceding predetermined time. In this case, the target vehicle speed obtained in the current control cycle is adopted, and when it is within the above range, the target vehicle speed obtained in the previous control cycle is adopted. There is an effect that it is possible to avoid the change to, and the ride feeling can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a control method of a travel control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing image data in the control device.

FIG. 3 is a block diagram showing a configuration of the traveling control device.

FIG. 4 is a flow chart for explaining the operation of the traveling control device.

FIG. 5 is a flowchart for explaining the operation of the traveling control device.

FIG. 6 is a diagram showing a process of each cycle of the travel control device.

FIG. 7 is a diagram showing a process of each cycle of the traveling control device.

FIG. 8 is a diagram showing a process of each cycle of the traveling control device.

FIG. 9 is a diagram showing the configuration of the claims of the present invention.

[Explanation of symbols]

 2a, 2b Runway reference line 19 Travel control device 50 Detection means 51 Deviation amount calculation means 52 Target vehicle speed setting means 53 Travel speed control means A Virtual straight line

Claims (5)

[Claims] 1. Detecting means for detecting a track reference line provided on a track, and vehicle width directions of the detected track reference line and a plurality of gazing points on a virtual straight line indicating a traveling direction of the vehicle. A deviation amount calculating means for obtaining a deviation, a target vehicle speed setting means for setting a target vehicle speed based on a change of each of the obtained deviations, and a traveling speed control means for controlling the traveling speed to reach the set target vehicle speed. A travel control device for an autonomous vehicle, comprising: 2. The deviation amount calculating means and the target vehicle speed setting means according to claim 1, when the change amount between the deviations is smaller than a predetermined value, the gazing point is moved away from the own vehicle and the target vehicle speed is increased. On the other hand, when the amount of change between the deviations is larger than a predetermined value, the gaze point is brought closer to the own vehicle and the target vehicle speed is decreased, and the traveling control device for the automatic traveling vehicle. 3. The vehicle according to claim 1, wherein the gazing point is located ahead of the host vehicle by a braking distance required to decelerate from a predetermined target vehicle speed to a predetermined minimum speed with a predetermined minimum deceleration. A traveling control device for an autonomous vehicle, characterized in that 4. The method according to claim 3, wherein the deviation amount calculating means obtains the first and second deviations of the first gazing point and the second gazing point located in front of the first gazing point, and the target speed calculating means When the change amount between the first and second deviations is smaller than a predetermined value, the second target vehicle speed corresponding to the second gazing point is set as the target vehicle speed, and when the change amount is larger than the predetermined value, the first gazing point is set. Is a target vehicle speed that corresponds to the first target vehicle speed. 5. The target vehicle speed set in the present control cycle by the target vehicle speed setting means according to claim 1, wherein the target vehicle speed set in the current control cycle is the minimum of the target vehicle speeds set in the control cycle in the immediately preceding predetermined time. When it is not within the range between the value and the maximum value, the target vehicle speed obtained in the current control cycle is adopted, and when it is in the above range, the target vehicle speed obtained in the previous control cycle is adopted. A traveling control device for a traveling vehicle.