WO2022205180A1

WO2022205180A1 - Automatic guided vehicle synchronizing method, device, and system

Info

Publication number: WO2022205180A1
Application number: PCT/CN2021/084685
Authority: WO
Inventors: 闵令宝; 李�浩; 华韬; 席宝时; 吴剑强
Original assignee: 西门子（中国）有限公司
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2022-10-06

Abstract

An automatic guided vehicle synchronizing method, device, and system. The synchronizing method comprises the following steps: S1: providing a reference point (R) on a second automatic guided vehicle (200); S2: continuously obtaining pictures from an industrial camera (C), and determining whether the reference point (R) on the pictures is within a first range (d); when the reference point (R) is deflected on a picture in a first direction, determining that a first automatic guided vehicle (100) is faster than the second automatic guided vehicle (200), and speeding down the first automatic guided vehicle (100) and/or speeding up the second automatic guided vehicle (200); when the position of the reference point (R) on a picture deviates from the first direction, determining that the first automatic guided vehicle (100) is slower than the second automatic guided vehicle (200), and speeding up the first automatic guided vehicle (100) and/or speeding down the second automatic guided vehicle (200); and iteratively performing step S2 until the reference point (R) is located within the first range (d) of the pictures.

Description

Synchronization method, device and system for automatic guided car

technical field

The invention relates to the field of industrial automation, in particular to a synchronization method, device and system for automatically guiding a trolley.

Background technique

Automatic Guided Vehicle (AGV, Automatic Guided Vehicle) is used more and more in industrial and commercial fields. For example, automated guided vehicles are used to transport components from a warehouse to a production line, and then automatically transport manufactured goods from the production line back to the warehouse.

For some larger-sized items, two or more automated guided vehicles may be required to transport from one location to another. How to determine the synchronization of automatic guided vehicles is very important.

The existing technology does not solve the synchronization problem of automatic guided vehicles well. One of the solutions in the prior art is to use a camera mounted on the automated guided vehicle to capture pictures of the automated guided vehicle, for example, the camera can be mounted on the ceiling of the workshop. Another solution is to use machine vision technology to locate automated guided carts. Another solution in the prior art is to control the calculation result of the automatic guided vehicle. However, the visual area and position accuracy of the camera are key issues.

SUMMARY OF THE INVENTION

A first aspect of the present invention provides a method for synchronizing automatic guided vehicles, wherein at least two automatic guided vehicles move together in a first direction, an industrial camera is installed on one of the first automatic guided vehicles, and the industrial camera pairs Another second automatic guided vehicle takes pictures, and the synchronization method includes the steps of: setting a reference point on the second automatic guided vehicle; continuously acquiring pictures from the industrial camera, and judging the reference point on the picture Whether it is within the first range, when the position of the reference point on the photo is outside the first range and is biased towards the first direction, it is determined that the speed of the first automatic guided vehicle is faster than the speed of the first automatic guided vehicle. the second automatic guided vehicle, and the speed of the first automatic guided vehicle is slowed down and/or the speed of the second automatic guided vehicle is adjusted faster, when the position of the reference point on the photo is at the location of the When it is outside the first range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle, and the speed of the first automatic guided vehicle is adjusted to a higher speed than that of the second automatic guided vehicle. /or slow down the speed of the second automatic guided vehicle, and perform step S2 iteratively until the reference point is located within the first range of the photo.

Further, the industrial camera is mounted on the side of the first automatic guided vehicle relative to the second automatic guided vehicle, and the reference point is set at the second automatic guided vehicle relative to the first automatic guided vehicle side.

Further, before the judging step, it also includes the following steps: performing denoising on the photo; increasing the contrast of the denoised photo to highlight the reference point of the photo; and extracting the reference point in the photo.

Further, the grayscale mean value of the photo is:

where k is the number of extreme grayscale pixels, where W _ij is the filtering window centered at coordinates (i, j) being processed, W ₀ is the default initial window size, and W _max is the maximum allowable value Window size, f _ij is the image gray value at coordinates (i, j), f _min is the minimum gray value in W _ij , f _max is the maximum gray value in W _ij , and f _med is W _ij The grayscale median in ;

If f _min <f _ij <f _max , the output image gray value is f _ij ; if f _min <f _med <f _max , the output is the gray median value f _med in W _ij , if W _ij+2 ≤ W _max , then W _ij =W _ij +2 to increase the filter window, otherwise the average gray level of the output image, if f _avg does not exist, that is, W _ij ×W _ij =k, then the average output gray level is f _avg =(f _min +f _max )/2.

A second aspect of the present invention provides a synchronization device for automatic guided vehicles, wherein at least two automatic guided vehicles move together in a first direction, an industrial camera is installed on one of the first automatic guided vehicles, and the industrial camera pairs Another second automatic guided vehicle takes pictures, and the synchronization method includes the steps of: setting a device, which sets a reference point on the second automatic guided vehicle; acquiring and determining means, which continuously obtains photos from the industrial camera, and judge whether the reference point on the photo is within the first range, and when the position of the reference point on the photo is outside the first range and is biased towards the first direction, judge the first range An automatic guided vehicle is faster than the second automatic guided vehicle, and the speed of the first automatic guided vehicle is slowed down and/or the speed of the second automatic guided vehicle is adjusted faster, when the reference point When the position on the photo is outside the first range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle, and the first automatic guided vehicle is determined to be slower than the second automatic guided vehicle. Speed up one automated guided vehicle and/or slow down the second automated guided vehicle until the reference point is within the first range of the photo.

Further, the synchronization device further includes an image processing device, wherein the image processing device further includes: a denoising device, which performs denoising on the photo; a contrast device, which increases the contrast on the denoised photo, so as to highlighting the reference points of the photo; extraction means extracting the reference points in the photo.

Further, the grayscale mean value of the photo is:

A third aspect of the present invention provides a synchronization system for an automated guided vehicle, the synchronization system comprising: a processor; and a memory coupled to the processor, the memory having instructions stored therein, the instructions being processed by the processor When executing, the electronic device is caused to perform actions, the actions include: setting a reference point on the second automatic guided vehicle; continuously acquiring photos from the industrial camera, and judging whether the reference point on the photo is on the first Within a range, when the position of the reference point on the photo is outside the first range and is biased toward the first direction, it is determined that the speed of the first automatic guided vehicle is faster than that of the second automatic guided vehicle automatic guided vehicle, and slow down the speed of the first automatic guided vehicle and/or speed up the second automatic guided vehicle, when the position of the reference point on the photo is in the first automatic guided vehicle When it is outside the range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle, and the speed of the first automatic guided vehicle is increased and/or the speed of the first automatic guided vehicle is increased. The speed of the second automatic guided vehicle is slowed down, and action S2 is iteratively performed until the reference point is located within the first range of the photo.

The present invention can easily identify the synchronization of the automatic guided vehicle, and automatically and accurately synchronize the speed of the automatic guided vehicle.

Description of drawings

1 is a schematic diagram of the installation of an automatic guided vehicle camera according to a specific embodiment of the present invention;

2 is a flowchart of a synchronization method for an automatic guided vehicle according to a specific embodiment of the present invention;

3 is a schematic diagram of different positions of reference points on a photo according to a specific embodiment of the present invention;

4 is a schematic diagram of denoising a photo including reference points according to a specific embodiment of the present invention;

FIG. 5 is a schematic diagram of increased contrast of a photo including reference points according to an embodiment of the present invention.

Detailed ways

The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

A first aspect of the present invention provides a method for synchronizing automatic guided vehicles, wherein an industrial camera is installed on one of the first automatic guided vehicles, and the industrial camera takes pictures of the other second automatic guided vehicle. 1 is a schematic diagram of the installation of an automatic guided vehicle camera according to a specific embodiment of the present invention, and FIG. 2 is a flowchart of a synchronization method of an automatic guided vehicle according to a specific embodiment of the present invention.

As shown in FIG. 1 , according to a preferred embodiment of the present invention, the first automatic guided vehicle 100 and the second automatic guided vehicle 200 jointly carry the same component, and one end of the component is placed on the upper surface 100b of the first automatic guided vehicle 100 . The other end of the element is placed on the upper surface 200b of the second automatic guided vehicle 200 . Wherein, the first automatic guided vehicle 100 and the second automatic guided vehicle 200 should keep the same speed and move forward in the direction shown by the direction S in the figure, so as to carry objects along the direction S and move forward. If the first automatic guided vehicle 100 and the second automatic guided vehicle 200 do not keep the same speed and move relatively statically, the components located above may tilt or even fall, causing damage to the items. Therefore, we should synchronize the first automatic guided vehicle 100 with the first automatic guided vehicle 100 and the second automatic guided vehicle 200. 2. The speed of the automatic guided vehicle 200.

The synchronization method of the automatic guided vehicle provided by the present invention includes step S1 and step S2.

First, step S1 is performed, and a reference point R is set on the second automatic guided vehicle 200 . Preferably, as shown in FIG. 1 , the reference point R is set at a side 200a of the second automatic guided vehicle 200 relative to the first automatic guided vehicle.

Then, step S2 is executed to continuously acquire photos from the industrial camera C on the first automatic guided vehicle 100 according to a certain frequency, and determine whether the reference point R on the photo is within the first range d. The industrial camera C is mounted on the side surface 200 a of the first automatic guided vehicle 100 relative to the second automatic guided vehicle 200 . When the reference point R on the photo is within the first range d, it is determined that the first automatic guided vehicle 100 and the second automatic guided vehicle 200 have the same speed, and the first automatic guided vehicle 100 maintains the current speed. Preferably, the first range d may be an area range or a length range. As shown in FIG. 3 , the reference point R ₁ on the photo P ₁ is at the center and is within the first range d, so it is judged that the first automatic guided vehicle 100 and the second automatic guided vehicle 200 have the same speed, then the first automatic guided vehicle 100 maintains the current speed.

The industrial camera C also needs to be combined with a picture processing module and an interface, wherein the interface is used to couple the automatic guided vehicle.

When the reference point on the photo is not within the first range, the judgment is continued. Specifically, when the position of the reference point on the photo is outside the first range and is inclined to the first direction, it is determined that the speed of the first automatic guided vehicle is faster than that of the second automatic guided vehicle , and slow down the speed of the first automatic guided vehicle and/or speed up the second automatic guided vehicle until the reference point is within the first range of the photo. According to the present embodiment, when the position of the reference point on the photo is higher, that is, when the position of the reference point R ₂ is higher on the photo P ₂ as shown in FIG. 3 , it is determined to adjust the speed of the first automatic guided vehicle 100 Slow, otherwise, the speed of the first automatic guided vehicle 100 is adjusted to be faster.

Similarly, when the position of the reference point on the photo is outside the first range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle. Guide the vehicle and speed up the first automated guided vehicle and/or slow down the second automated guided vehicle until the reference point is within the first range of the photo. As shown in FIG. 3 , when the position of the reference point R ₃ is lower on the photo P ₃ , the speed of the first automatic guided vehicle is increased and/or the speed of the second automatic guided vehicle is decreased. until the reference point is within the first range of the photo.

Step S2 is performed iteratively until the reference point R is located within the first range of the photo.

Further, before the judging step, it also includes the following steps: performing denoising on the photo; increasing the contrast of the denoised photo to highlight the reference point of the photo; and extracting the reference point in the photo. FIG. 4 is a schematic diagram of denoising a photo including reference points according to a specific embodiment of the present invention. As shown in FIG. 4 , the photo P ₄ includes a reference point R ₄ and also includes a lot of noise N, and denoising is to remove the noise N. The contrast of FIG. 4 also needs to be increased to improve the contrast between the reference point and other areas of the photo. FIG. ₅ is a schematic diagram of increasing the contrast of a photo including a reference point according to a specific embodiment of the present invention, as shown in FIG. The contrast with other areas of the photo is obvious, so it is easier to judge the synchronization degree of the automatic guided car.

Specifically, the purpose of photo denoising is to highlight reference points and erase other information. For example, if someone happens to walk by, the image of the person will be erased. Among them, image denoising mainly removes salt and pepper noise or impulse noise.

Among them, W _ij is the filter window being processed and centered at coordinates (i, j), W ₀ is the default initial window size, and W _max is the maximum allowed window size. f _ij is the image gray value at coordinates (i, j), f _min is the minimum gray value in W _ij , f _max is the maximum gray value in W _ij , f _med is the gray value in W _ij median value.

Specifically, if f _min <f _ij <f _max , the gray value of the output image is f _ij . If f _min <f _med < f _max , the output is the grayscale median value f _med in W _ij , if W _ij+2 ≤W _max , then W _ij =W _ij +2 to increase the filter window, otherwise the output image Grayscale mean. Among them, the average gray value of the output maximum window except all the minimum grayscale pixels and the maximum grayscale pixels is:

Among them, k is the number of extreme grayscale pixels. If f _avg does not exist, that is, W _ij ×W _ij =k, then the output gray mean value f _avg =(f _min +f _max )/2.

Further, the grayscale mean value of the photo is:

While the content of the present invention has been described in detail by way of the above preferred embodiments, it should be appreciated that the above description should not be construed as limiting the present invention. Various modifications and alternatives to the present invention will be apparent to those skilled in the art upon reading the foregoing. Accordingly, the scope of protection of the present invention should be defined by the appended claims. Furthermore, any reference signs in a claim shall not be construed as limiting the claim involved; the word "comprising" does not exclude other claims or means or steps not listed in the specification; Words such as "two" are used only to denote names and do not denote any particular order.

Claims

A method for synchronizing automatic guided vehicles, wherein at least two automatic guided vehicles move together in a first direction, an industrial camera is installed on one of the first automatic guided vehicles, and the industrial camera is directed to the other second automatic guided vehicle Taking pictures of the car, the synchronization method includes the following steps:

setting a reference point on the second automatic guided vehicle;

Continuously acquiring photos from the industrial camera, and judging whether the reference point on the photo is within the first range,

When the position of the reference point on the photo is outside the first range and is biased toward the first direction, it is determined that the speed of the first automatic guided vehicle is faster than that of the second automatic guided vehicle, and slowing down the speed of the first automatic guided vehicle and/or speeding up the speed of the second automatic guided vehicle,

When the position of the reference point on the photo is outside the first range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle, and increase the speed of the first automatic guided vehicle and/or reduce the speed of the second automatic guided vehicle,

Step S2 is performed iteratively until the reference point is located within the first range of the photo.
The method for synchronizing an automatic guided vehicle according to claim 1, wherein the industrial camera is installed on the side of the first automatic guided vehicle relative to the second automatic guided vehicle, and the reference point is set at the The side of the second automatic guided vehicle relative to the first automatic guided vehicle.
The method for synchronizing an automatic guided vehicle according to claim 1, further comprising the following steps before the judging step:

performing denoising on the photo;

Add contrast to the denoised photo to highlight the reference points of the photo;

Reference points in the photo are extracted.
The method for synchronizing an automatic guided vehicle according to claim 4, wherein the average grayscale value of the photo is:

where k is the number of extreme grayscale pixels, where W ij is the filtering window centered at coordinates (i, j) being processed, W 0 is the default initial window size, and W max is the maximum allowable value Window size, f ij is the image gray value at coordinates (i, j), f min is the minimum gray value in W ij , f max is the maximum gray value in W ij , and f med is W ij The grayscale median in ;

If f min <f ij <f max , the output image gray value is f ij ; if f min <f med <f max , the output is the gray median value f med in W ij , if W ij+2 ≤ W max , then W ij =W ij +2 to increase the filter window, otherwise the average gray level of the output image, if f avg does not exist, that is, W ij ×W ij =k, then the average output gray level is f avg =(f min +f max )/2.
Synchronization device for automatic guided vehicles, wherein at least two automatic guided vehicles move together in a first direction, an industrial camera is mounted on one of the first automatic guided vehicles, and the industrial camera is directed to the other second automatic guided vehicle. Taking pictures of the car, the synchronization method includes the following steps:

setting means for setting a reference point on the second automatic guided vehicle;

an acquisition judging device, which continuously acquires a photo from the industrial camera, and determines whether a reference point on the photo is within a first range,

When the position of the reference point on the photo is outside the first range and is inclined to the first direction, it is determined that the speed of the first automatic guided vehicle is faster than that of the second automatic guided vehicle, and slowing down the speed of the first automatic guided vehicle and/or speeding up the speed of the second automatic guided vehicle,

When the position of the reference point on the photo is outside the first range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle, and increase the speed of the first automatic guided vehicle and/or reduce the speed of the second automatic guided vehicle,

until the reference point is within the first range of the photo.
The automatic guided vehicle synchronization device according to claim 5, wherein the industrial camera is installed on the side of the first automatic guided vehicle relative to the second automatic guided vehicle, and the reference point is set at the The side of the second automatic guided vehicle relative to the first automatic guided vehicle.
The synchronization device for an automatic guided vehicle according to claim 5, wherein the synchronization device further comprises an image processing device, wherein the image processing device further comprises:

a denoising device that performs denoising on the photo;

a contrast device that adds contrast to the denoised photo to highlight the reference points of the photo;

Extraction means that extracts reference points in the photograph.
The automatic guided vehicle synchronization device according to claim 7, wherein the average grayscale value of the photo is:

where k is the number of extreme grayscale pixels, where W ij is the filtering window centered at coordinates (i, j) being processed, W 0 is the default initial window size, and W max is the maximum allowable value Window size, f ij is the image gray value at coordinates (i, j), f min is the minimum gray value in W ij , f max is the maximum gray value in W ij , and f med is W ij The grayscale median in ;

If f min <f ij <f max , the output image gray value is f ij ; if f min <f med <f max , the output is the gray median value f med in W ij , if W ij+2 ≤ W max , then W ij =W ij +2 to increase the filter window, otherwise the average gray level of the output image, if f avg does not exist, that is, W ij ×W ij =k, then the average output gray level is f avg =(f min +f max )/2.
A synchronization system for an automatic guided vehicle, characterized in that the synchronization system includes:

processor; and

a memory coupled to the processor, the memory having stored therein instructions that, when executed by the processor, cause the electronic device to perform actions, the actions comprising: on the second automated guided vehicle set a reference point;

Continuously acquiring photos from the industrial camera, and judging whether the reference point on the photo is within the first range,

When the position of the reference point on the photo is outside the first range and is inclined to the first direction, it is determined that the speed of the first automatic guided vehicle is faster than that of the second automatic guided vehicle, and slowing down the speed of the first automatic guided vehicle and/or speeding up the speed of the second automatic guided vehicle,

When the position of the reference point on the photo is outside the first range and deviates from the first direction, it is determined that the speed of the first automatic guided vehicle is slower than that of the second automatic guided vehicle, and increase the speed of the first automatic guided vehicle and/or reduce the speed of the second automatic guided vehicle,

Action S2 is performed iteratively until the reference point is within the first range of the photo.