JPH01300311A - Unmanned vehicle guiding device - Google Patents

Abstract

PURPOSE:To ensure the stable guided drive of an unmanned vehicle and also to ensure the accurate stop control of the vehicle by performing the image pickup of two zones at front and right under a guide line set on a floor surface and detecting the position of the guide line from the front picture in a traveling mode and the lower picture before and in a stop mode respectively to perform the automatic steering operation. CONSTITUTION:The shift value of an unmanned vehicle 1 is calculated against a guide line 11 based on an upper front picture a1 of a ITV camera 12 for execution of the automatic steering control while the vehicle 1 is traveling. Then the steering control is carried out based on a lower picture b1 when the vehicle 1 gets close to a fixed stop position. At the same time, the vehicle 1 is stopped at the fixed stop position. Thus a front guide line is available while the vehicle 1 is travelling and the traveling speed of the vehicle can be increased. While said shift value of the vehicle is detected based on a lower guide line right before a stop mode when the speed of the vehicle is slowed down or in the stop mode. In such a way, the steering control is carried out for the vehicle 1 and therefore the vehicle 1 can be stopped at tan accurate stop position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an automatic guidance system for an unmanned vehicle such as an automatic guided vehicle.

(Prior technology) Conventionally, as a guidance method for automatic guided vehicles, a sensor that shines light on an optical reflective tape attached to the floor surface, receives the reflected light, detects the relative position of the reflective tape and the vehicle, and receives the light. An unmanned vehicle guidance device is known that uses output to detect deviation between a reflective tape and a vehicle and performs steering.

5 and 6 show a conventional example of such an unmanned vehicle guidance system, in which a guided vehicle 1 is equipped with drive wheels 2 on the left and right, caster wheels 3 are provided at four locations on the front, rear, left and right, and A light guide sensor 4 is provided at the lower front portion of the conveyor 111, and is further provided with a travel control section 5, a motor drive section 6, and a motor 7. Further, as shown in FIG. 6, the light guide sensor 4 includes a light sensor 9 that projects light onto a reflective tape 8 mounted on the floor surface and receives the reflected light.

Therefore, in the automatic guided vehicle 1, the optical sensor 9 of the optical guidance sensor 4 provided at the front lower part of the automatic guided vehicle 1 shines light toward the reflective tape 8 directly below, and receives the reflected light from the reflective tape 8.
The relative position of the automatic guided vehicle 1 with respect to the reflective tape 8 is detected, and when the reflective tape 8 is detected at the center of the optical sensor 9, the steering is not performed, and for example, when the reflective tip 18 is detected at the right side of the optical sensor 9, the steering is performed. Conversely, when the vehicle is detected on the left side, the travel control section 5 controls the vehicle to steer the vehicle to the right, and the vehicle travels along the reflective tape 8 as a guide line.

In this conventional unmanned vehicle guidance system, the unmanned guided vehicle 1
Drive wheels 2 are provided on the left and right sides of the front and rear center of the wheel, and steering is performed using the difference in rotation speed between the left and right drive wheels 2°2.When steering to the right, the rotation speed of the right drive wheel is used to perform steering. When steering to the left, the rotation speed of the left drive wheel is lowered.

(Problem to be solved by the invention) However, in such a conventional unmanned vehicle guidance device,
Detection of reflective tape 8 as a guide line by unmanned transport 11
Since this is done by looking directly below within the projected area of No. 11, it is difficult to stabilize the traveling, and due to this, there is a problem that the speed during unmanned transportation cannot be increased.

The present invention has been made to solve these conventional problems, and it is an object of the present invention to provide an unmanned vehicle guidance system that is capable of stable guided travel even at high speeds.

[Structure of the Invention] (Means for Solving Problem Li1) The unmanned vehicle guidance device of the present invention displays a guidance line provided on the driving road and two zones from above the unmanned vehicle, in front and directly below, on the same screen. an image capturing means for capturing an image in an upper stage and a lower stage; an image processing means for detecting the guidance line position by processing image signals outputted from the imaging means separately for the upper stage image and the lower stage image; and an image processing means for detecting the guidance line position; Based on the route data, a deviation amount detecting means detects a positional deviation of the unmanned vehicle with respect to the guidance line using an upper forward image while driving and a lower downward image immediately before and during stopping; and an output from the deviation amount detecting means. and steering means for steering the unmanned vehicle based on the deviation signal.

(Function) In the unmanned vehicle guidance device of the present invention, the m* means images two zones in front and directly below the unmanned vehicle in the upper and lower stages of the same screen, and the image signal output from this imaging means is transmitted to the upper stage. The image and the lower image are processed separately, and the deviation amount detection means detects the deviation product based on the upper front image when the unmanned vehicle is moving, and based on the lower image when the unmanned vehicle is slowing down and just before stopping or while the vehicle is stopped. Detects the deviation of an unmanned vehicle from the guidance line.

This allows the unmanned vehicle to use the guidance line in front of it as a guide to increase its driving speed, and when the vehicle is slowing down just before or during a stop, it can shift based on the guidance line below. It is possible to perform steering by detecting the amount, and it is possible to stop at an accurate position.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 is an explanatory diagram showing an example of a device configuration according to an embodiment of the present invention, and FIG. 2 is a circuit configuration diagram.

As shown in FIG. 1, the conveyance vehicle 1 is provided with drive wheels 2 on the left and right sides of the rear center portion, as in the conventional example, and is provided with caster wheels 3 at four locations in the front, back, left and right.

During unmanned transport 1, there is also an ITV camera 12 for imaging the guide line 11 provided on the floor 10, a front imaging mirror 13 for imaging the gravity point a of the transport vehicle 1, and the transport vehicle 1. An image processing unit 15 that processes signals from the ITV camera 12 and travel control of the transport 111 based on the image information processed by the image processing unit 15. The vehicle is equipped with a travel control section 16 that performs the following.

The detailed configuration of the image processing section 15 and the traveling control section 16 is described in the second section.
As shown in the figure, the image processing unit 15 includes an ITV camera 12
The line position detecting section 18 includes an A/D converter 17 for receiving an image signal from the line position detecting section 18 and a line position detecting section 18. The travel control section 16 also includes a deviation detection section 19 for the output signal from the image processing section 15, a steering calculation section 20, left and right -9 rotation command sections 21a and 21b, and a motor control section 228.
．． 22b, and a Daruma pattern generating section 23.

The operation of the unmanned vehicle guidance system having the above configuration will be explained next.

In the guided vehicle 1, the motor rotation command parts 21a and 21b give motor rotation commands to the motor control parts 22a and 22b in response to the speed pattern command from the speed pattern generation part 23, and the motor a and I+ control parts 22a and 22b The left and right drive wheels 2 are rotationally driven to guide the guide line 1 on the floor 10.
Drive along 1.

Here, when steering the conveyance vehicle 1, it is done by rotating the left and right drive wheels 2 at the same rotation speed when moving straight, and by lowering the rotation speed of the right drive wheel when steering to the right. When steering to the left, the rotation speed of the left drive wheel 2 is lowered.

Therefore, the ITV camera 12 has a front 1lil image II3.
and downward 1 [ii of point a in front via the mirror 14! The image at point b immediately below and the image at point b are simultaneously captured on the same screen and input to the A/D converter 17 of the image processing section 15.

In this image processing section 15, an A/D converter 17 converts the input signal into a digital image signal, and a line position detection section 18 converts the input signal into a digital image signal.
give to

The line position detection unit 18 includes an addition function unit that adds the digital image signal in the vertical direction to obtain the vertical peripheral distribution of the input image, and a differentiation function unit that differentiates the vertical peripheral distribution obtained by the addition function unit. It is equipped with a maximum/minimum position detection function section that calculates the horizontal addresses of the maximum and minimum values from the output result of this differentiation function section, and from the maximum/minimum addresses output from this maximum/minimum position detection function section. The position of the guide line 11 is detected.

Once the line position is detected in the image processing section 15 in this manner, this signal is output to the deviation detecting section 19 of the traveling control section 16.

The deviation bow detection unit 19 sets the deviation ff1o when the center of the image of the guide line 11 comes to the center of the screen on the screen of the ITV camera 12, and the line position detection unit 18
The difference between the address at the center of the guide line 11 and the address at the center of the guide line 11 is detected as a shift. Therefore, for example, if it is shifted to the right, it is assumed to be 10Δ, and if it is shifted to the left, it is -
Let it be Δ.

The deviation amount detection output from the deviation constant detection section 19 is input to the steering calculation section 20, where the steering amount is changed to FI! calculated. In the case of this embodiment, since a system is adopted in which steering is performed based on the difference in rotational speed between the left and right wheels, the amount of steering is converted into the difference in rotational speed between the left and right drive wheels. Therefore, when the deviation amount detection signal from the deviation detection section 19 is +Δ, the output of the steering calculation section 20 is
This is a command to lower a by Δn, and if the deviation amount is -Δ, a command to lower the left motor rotation command section 21b by Δn is output.

The speed pattern generation section 23 generates a speed pattern according to the travel command and outputs the speed pattern to the motor rotation command section 21a.

21b, and is output to the motor rotation command section 21a.
, 21b gives a rotational speed command to each of the control units 22a and 22b in accordance with the speed command from the speed pattern generation unit 23, controls the rotational speed of the motors of the left and right drive wheels 2, and moves the conveyance vehicle 1 along the guidance line. 11.

Therefore, from the steering calculation unit 20 to either the left or right motor rotation command unit 218 or 21b, Δn is set as described above.
When a command is given to reduce the speed by
By applying the speed i lI command value to the motor 1I11 control unit 22a or the motor control unit 22b, left and right steering can be performed.

In this way, while the conveyance vehicle 1 is traveling, it moves based on the image of point a in front, but when the positional accuracy when stopped is a problem, it moves based on the image of point a in front. If control is performed, sufficient stopping position accuracy cannot be ensured. Therefore, as shown in FIG. 3, the front image a1 is displayed in the upper part of the screen C of the ITV camera 12, and the lower image b1 is shown in the lower part. The upper front image ea+ is subjected to image processing by the line position detecting section 18 of the image processing section 15 to perform line position detection, and when it is about to stop, the line position detection processing is switched to the line position detection process based on the lower lower image b1. The speed pattern generation unit 2 determines which of the upper image a1 and the lower image b1 to adopt.
It is assumed that the line position detection unit 18 automatically selects the speed command No. 3.

In the case of stopping at a fixed position, as shown in FIG.
b is provided, and the bottom lower image of the ITV camera 12 if>
b+ captures this stop mark 11b, and the line position detection unit 18 determines the gravity center position address where the center of the stop mark 11b in the vertical and horizontal directions is the lower image fg! When it is detected that the transport vehicle 1 has come to the center of b+, the transport vehicle 1 is controlled so as to stop at the fixed position.

Therefore, when the line position detection unit 18 is about to stop depending on the magnitude of the speed command value from the speed pattern generation unit 23, the line position detection unit 18 detects the address of the center position of the stop mark 11b in the horizontal direction and the center position of the stop mark 11b in the vertical direction in the lower image b1. The address of the section is also crushed and outputted to the misalignment detection section 19.

Therefore, when the offset rh of the stop mark 11b becomes O in both the vertical and horizontal directions, the deviation rh detection section 19 detects the motor rotation command section 21a, 2 via the steering calculation section 20.
A motor stop command is given to 1b to cause it to stop at a fixed position.

In this way, while the transport vehicle 1 is running, [TV camera 1
Based on the upper front image a1 of 2, the automatic steering 4+ control is performed by crushing the slippage with respect to the guidance line 11, and when the fixed position stop is approaching, the lower step lower image ab+ performs steering control, and the Pn 17-ri 11b This makes it possible to stop at a fixed position.

In addition, in the above embodiment, the speed pattern generating section 2
Based on the speed command No. 3, the line position detection unit 18 detects the ITV
Upper image Qa to lower image fill on screen C of camera 12
) + to perform fixed position stop control, but the present invention is not limited to this embodiment, and the automatic guided vehicle 1
It may be possible to automatically switch when the distance from the traveling position of the automatic guided vehicle 1 to the fixed position stop point falls within a certain value based on route data on the side and a distance counter possessed by the automatic guided vehicle 1.

Further, in the above embodiment, only the amount of deviation with respect to the guide line was detected, but the amount of deviation is obtained from the upper front image al and the lower lower image b1 of the screen C of the ITV camera 12, and the amount of deviation of the guided vehicle 1 is calculated from both deviations. By controlling the attitude angle, it becomes possible to not only stop the transport vehicle 1 at a fixed position but also control the attitude angle of the transport vehicle 1 to a normal value.

Furthermore, if the guidance line is not found on the forward image a1 captured by the ITV camera 12, it is assumed that the image of the forward point a cannot be captured due to sunlight reflection or other reasons.
In this case, it is also possible to automatically switch to the lower image b1, detect the line position, and perform misalignment detection.

[Effects of the Invention] As described above, according to the present invention, the imaging means images two zones, the position in front of the guide line on the floor and the position directly below the guide line, and while the vehicle is running, the forward image is used to capture images immediately before the stop and when the guide line is stopped. At times, the line position is detected using a downward image and automatic steering is performed, so it is possible to perform stable guided travel even at higher travel speeds compared to the conventional example, and it is also possible to perform stop control accurately.

[Brief explanation of the drawing]

Fig. 1 is an equipment configuration diagram of an embodiment of the present invention, Fig. 2 is a circuit block diagram of the above embodiment, Fig. 3 is an explanatory diagram of an example of an image taken by an ITV camera according to the above embodiment, and Fig. 4 is an illustration of the above embodiment. FIG. 5 is an explanatory diagram showing the fixed position stop mark portion of the guide line in the embodiment, FIG. 5 is an explanatory diagram of the conventional example, and FIG. 6 is an explanatory diagram showing the light adjustment sensor in the conventional example. 1... Unmanned transport I 2... Drive wheel 10
... Floor surface 11 ... Guidance line 11
a... Traveling line part 11b... Stop mark 1
2... ITV camera 13... Mirror for forward Ill image 14... Mirror for downward leaping image 15... Image processing section 16... Travel control section 17... A/D
Converter 18...Line position detection section 19...Displacement amount detection section 20...Steering operation section 21a, b...Motor rotation command section 22a, b...Motor control section 23...Speed Pattern generation part 4℃ Buried Buried Yasuo Miyoshi Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

Claims (1)

[Claims] A guide line provided on the driving road, an imaging means for capturing images of two zones in front and directly below the unmanned vehicle from above on the same screen, and an image signal output from the imaging means as the upper image. An image processing means detects the guidance line position by separately processing the lower image and the lower image, and based on the driving route data of the unmanned vehicle, the upper front image is used while driving, and the lower lower image is used just before and while stopping. An unmanned vehicle guidance device comprising a deviation amount detection means for detecting the amount of positional deviation of an unmanned vehicle with respect to a guidance line, and a steering means for steering the unmanned vehicle based on a deviation signal output from the deviation amount detection means.