JP5729736B1 - Automated transport system - Google Patents

Abstract

An unmanned transfer system that is stronger against dirt and defects on a guide line. An unmanned conveyance system (1) includes a guide line (L) laid on a road surface and colored in a color different from that of the road surface, and an imaging area (A) attached to a vehicle body (3) and including the guide line (L). And an automatic guided vehicle 2 having an image pickup means 5 for generating image data. The guide line L is composed of two different colors, a first color and a second color. The first color and the second color are colored so that the boundary line Yc generated by the difference in color extends in the laying direction of the guide line L. The automatic guided vehicle 2 performs image processing on the image data to extract and specify the boundary line Yc so that the predetermined portion P on the center line C in the width direction of the vehicle body 3 is on the specified boundary line Yc. Travel along the guide line L. [Selection] Figure 1

Description

  The present invention relates to an automatic guided system including a guide line and an automatic guided vehicle that travels along the guide line.

  2. Description of the Related Art Conventionally, in a factory, a warehouse, and the like, an unmanned conveyance system that conveys loads by causing an automatic guided vehicle to travel along a predetermined traveling route is used. Various types of unmanned conveyance systems are known. As one of the unmanned transport systems, as shown in FIG. 5, the vehicle travels along the guide line L ′ while detecting the guide line L ′ by the imaging means 5 such as a CCD camera and the guide line L ′ laid on the road surface. There is an image guidance type equipped with an automatic guided vehicle 2 (see, for example, Patent Document 1 and Patent Document 2).

  The guide line L ′ is colored in a single color different from the road surface. The guide line L 'is formed of tape or paint.

  With reference to FIGS. 5 and 6A, the automatic guided vehicle 2 sequentially images a predetermined imaging area A including the guide line L ′ by the imaging means 5 at regular time intervals during traveling. The traveling control means 6 of the automatic guided vehicle 2 extracts boundary lines Wl and Wr between the guide line L ′ and the road surface by performing predetermined image processing such as binarization processing on the obtained image data, The center line Lc in the width direction of the guide line L ′ is calculated and specified based on the two boundary lines Wl and Wr. The travel control means 6 drives and steers the wheels 4 so that the width direction center line C of the vehicle body 3 is on the width direction center line Lc of the guide line L ′, thereby causing the vehicle body 3 to travel. That is, the automatic guided system travels the automatic guided vehicle 2 using the center line Lc in the width direction of the guide line L ′ as a travel center.

  In an image guidance type unmanned conveyance system, the guidance line L ′ may be soiled or chipped. For example, as shown in FIG. 6B, a part of the boundary line Wl may be covered with the dirt D in the imaging region A. The traveling control means 6 performs image processing on the captured image data, thereby extracting a portion free of dirt D in the boundary line Wl in the imaging region A, and extending or connecting the extracted boundaries. The part that could not be extracted due to the dirt D is complemented. And the traveling control means 6 specifies the width direction center line Lc based on the complemented boundary line Wl and boundary line Wr. Thereby, the automatic guided system can run the automatic guided vehicle 2 without shifting with respect to the center line Lc in the width direction of the guide line L ′ even if a part of the boundary line W1 is dirty in the imaging region A. .

JP 2012-230601 A JP 2012-208592 A

  For example, as shown in FIG. 6C, the road surface may become dirty over a long section, and the entire boundary line Wl may be covered with the dirt D in the imaging region A. In this case, the boundary line Wl cannot be extracted or complemented as described above. At this time, the traveling control means 6 misidentifies the line Wl ″ determined from the boundary between the dirt D and the guidance line L ′ as the boundary line Wl, and the guidance line L ′ is moved from the original position. The line Lc ″ shifted in the width direction is specified as the width direction center line Lc. As a result, the automatic guided vehicle 2 travels with this line Lc ″ as the travel center. In other words, the automatic guided vehicle 2 travels along the guide line L ′ in a state of being shifted from the correct travel position in the width direction of the guide line L ′.

  Further, not only when the dirt D adheres to the guide line L ′ as described above, but also when the guide line L ′ is missing from the side edge over a long section, the automatic guided vehicle 2 is running off. .

  As described above, the conventional unmanned conveyance system is vulnerable to dirt and defects on the guide line L 'over a long section.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the unmanned conveyance system stronger with respect to the stain | pollution | contamination and defect | deletion of a guide line.

In order to solve the above-mentioned problem, an unmanned conveyance system according to the present invention includes a guide line laid on a road surface and colored in a color different from the road surface,
An automatic guided vehicle having a vehicle body and an imaging unit attached to the vehicle body and imaging an imaging region including the guide line to generate image data of the imaging region;
The guide line is composed of two colors, a first color and a second color, which are different from each other, and the first boundary line generated by the difference in color between the first color and the second color is the guide color. It is colored to extend in the direction of laying the line,
The automatic guided vehicle extracts and specifies the first boundary line by performing image processing on the image data, and the predetermined position on the center line in the width direction of the vehicle body is specified on the first boundary line. An unmanned transport system that travels along the guide line so that
When the first boundary line is not extracted at all, or when the extracted first boundary line is less than a predetermined ratio, the automatic guided vehicle has the first of the guide lines extracted from the image data. A second boundary line caused by the difference between the color of the road surface and the color of the road surface, and a third boundary line caused by the difference between the second color of the guide line extracted from the image data and the color of the road surface The first boundary line is specified based on both or one of the lines .

  Preferably, the guide line is configured such that the first boundary line coincides with a center line in the width direction of the guide line.

  By providing the above configuration, the present invention can provide an unmanned conveyance system that is stronger against dirt and defects on the guide line.

It is a top view which shows the schematic structure of the unmanned conveyance system which concerns on this invention. FIG. 2A is an example of a guide line in the present invention, FIG. 2A is a straight portion of the guide line, and FIG. 2B is a curved portion of the guide line. FIG. 3A and FIG. 3B are examples when the guide line in the present invention is dirty. 4A and 4B are examples when the guide line in the present invention is dirty. It is a top view which shows the schematic structure of the conventional unmanned conveyance system. FIG. 6A is an example of a conventional guide line, FIG. 6A is a diagram in which the guide line is not soiled, and FIGS. 6B and 6C are diagrams in the case where the guide line is soiled.

Hereinafter, an automatic transfer system according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the automatic guided system 1 includes a guide line L laid on a road surface and colored in a color different from the road surface, and an automatic guided vehicle 2 that travels along the guide line L.

  The automatic guided vehicle 2 includes a vehicle body 3, wheels 4 provided at four corners of the vehicle body 3, and an imaging unit 5 such as a CCD camera attached to the vehicle body 3. The imaging means 5 is arranged on the center line C in the width direction of the vehicle body 3. The imaging means 5 has its imaging surface facing the road surface, images the imaging area A including the guide line L, and generates image data of the imaging area A. The automatic guided vehicle 2 captures images at regular time intervals while traveling and sequentially generates image data.

  The automatic guided vehicle 2 includes a traveling control unit 6 that drives and steers the wheel 4 based on the image data sequentially sent from the imaging unit 5 to cause the vehicle body 3 to travel. The traveling control means 6 is composed of a microcomputer, a storage device and the like.

  As shown in FIGS. 2A and 2B, the guide line L is laid on the road surface and extends along the travel route of the unmanned conveyance system 1. The guide line L is composed of two different colors, a first color and a second color. The first color and the second color are colored so that a central boundary line Yc (first boundary line), which is a boundary line generated by the difference in color, extends along the laying direction of the guide line L. . The guide line L extends along the travel route, and includes a straight portion as shown in FIG. 2A and a curved portion as shown in FIG. 2B.

  The color of the road surface, the first color of the guide line L, and the second color of the guide line L can be clearly distinguished. As an example, the color of the road surface is gray or green, and one of the two colors of the guide line L is red and the other is yellow. The guide line L is formed by applying two colors of paint to the road surface, or adhering two tapes of different colors to each other adjacent to each other.

  Hereinafter, the portion colored in the first color is referred to as the left line portion Ll, and the portion colored in the second color is referred to as the right line portion Lr. Further, the boundary line generated by the color difference between the left line portion Ll and the road surface is defined as the left boundary line Yl (second boundary line), and the boundary line generated by the color difference between the right line portion Lr and the road surface is defined as the right boundary line. Let Yr be the third boundary line. The left line portion Ll and the right line portion Lr extend in parallel to each other and have the same width, and the central boundary line Yc coincides with the width direction center line Lc of the guide line L.

  The automatic guided vehicle 2 specifies the center boundary line Yc of the guide line L by the imaging unit 5 and the traveling control unit 6, and a predetermined portion P on the center line C in the width direction of the vehicle body 3 (see FIGS. 1 and 2). The vehicle runs along a straight line portion as shown in FIG. 2A or a curved portion as shown in FIG. 2B of the guide line L so that (in this embodiment, the center of the imaging region A) is on the central boundary line Yc. That is, the automatic guided vehicle 2 identifies the central boundary line Yc that is the boundary between the first color and the second color of the guide line L, and travels using this as the traveling center. Hereinafter, a method for specifying the central boundary line Yc will be specifically described.

  The traveling control means 6 of the automatic guided vehicle 2 performs predetermined image processing such as binarization processing with an appropriate threshold value on the image data of the imaging area A including the guide line L sequentially sent from the imaging means 5. Thus, the center boundary line Yc is extracted and specified.

  As described above, according to the configuration in which the guide line L has two colors and the central boundary line Yc which is the boundary between the colors is extracted by image processing, the left boundary line Yl or the right side in the imaging region A as shown in FIG. 3A. Even when the dirt D adheres to all or part of the boundary line Yr, or when the side edge of the guide line L is missing due to peeling of the tape or paint, the automatic guided vehicle 2 is moved with respect to the central boundary line Yc. It can be run without deviation.

  As shown in FIG. 3B, when a part of the central boundary line Yc is dirty in the imaging region A, the extracted part without the dirt D being attached is extended or connected. Thus, the center boundary line Yc is specified by complementing the portion that cannot be extracted due to the dirt D.

  However, with the above configuration alone, as shown in FIG. 4A, when the dirt D is attached to the entire central boundary line Yc in the imaging region A, the central boundary line Yc cannot be extracted by image processing and may be supplemented. Can not. Further, as shown in FIG. 4B, in the imaging region A, when the dirt D adheres to most of the central boundary line Yc, only a small part of the central boundary line Yc can be extracted. As shown in FIG. 4B, if the guide line L in the imaging region A is a straight line portion, it is possible to accurately complement a portion that cannot be extracted as described above from a slightly extracted portion. However, as shown in FIG. 2B, the guide line L in the imaging region A may be a curved portion. In this case, if most of the central boundary line Yc is dirty, the portion that cannot be extracted cannot be accurately complemented, As a result, the center boundary line Yc cannot be accurately specified.

  Therefore, as a result of the image processing for extracting the central boundary line Yc, the traveling control unit 6 does not extract the central boundary line Yc as described above if the extracted central boundary line Yc is equal to or greater than a predetermined ratio. The center boundary line Yc is specified by complementing the part.

  Here, the traveling control means 6 determines whether or not the extracted portion of the central boundary line Yc is equal to or greater than a predetermined ratio, for example, in the vertical direction of the imaging area A, as shown in FIG. This is performed depending on whether the ratio (t / T) of the extracted portion t of the central boundary line Yc to T is greater than or equal to a predetermined value. The predetermined ratio or more is, for example, 30% or more, that is, t / T ≧ 0.3.

  On the other hand, when the central boundary line Yc cannot be extracted at all, or when the traveling control means 6 can extract the central boundary line Yc, the traveling control means 6 is less than a certain ratio (for example, t When /T<0.3), the center boundary line Yc is specified as follows.

  The traveling control means 6 performs predetermined image processing such as binarization processing on the image data of the imaging area A with an appropriate threshold value, and extracts both the left boundary line Yl and the right boundary line Yr, Based on these boundary lines Yl and Yr, the central boundary line Yc is determined and specified. Specifically, the center boundary line Yc is specified by determining the center of the left boundary line Yl and the right boundary line Yr.

  Note that the travel control means 6 specifies the center boundary line Yc based on either the left boundary line Yl or the right boundary line Yr, without being based on both the left boundary line Yl and the right boundary line Yr. Also good. When based on the left boundary line Yl, for example, since the width of the left line part Ll is known in advance, the center boundary is determined by calculating a position offset to the right side by the width of the left line part Ll from the extracted left boundary line Yl. The line Yc is specified. The same applies to the case based on the right boundary line Yr, and the center boundary line Yc is specified by determining the position offset to the left side by the width of the right line part Lr from the extracted right boundary line Yr.

  As described above, the traveling control means 6 can detect any of the above when the central boundary line Yc cannot be extracted at all or when the extracted portion of the central boundary line Yc is less than a certain ratio even if it can be extracted. The central boundary line Yc is specified by this method. Thereby, as shown in FIG. 4A, even when the central boundary line Yc is dirty over a long section, the automatic guided vehicle 2 can travel without being deviated from the central boundary line Yc.

  Further, when the central boundary line Yc is not extracted at all, or when the extracted central boundary line Yc is less than a predetermined ratio, the following may be performed. The traveling control means 6 performs image processing for extracting the left boundary line Yl and the right boundary line Yr, and when both the left boundary line Yl and the right boundary line Yr can be extracted, the extracted left boundary line Yl and right boundary line The center boundary line Yc is specified based on both or either of the lines Yr. On the other hand, when only one of the left boundary line Yl and the right boundary line Yr can be extracted, the traveling control means 6 identifies the central boundary line Yc based on the extracted boundary line.

  According to this method, not only in the case of FIG. 4A but also in the imaging region A, as shown in FIG. 4B, the central boundary line Yc and one boundary line between the guide line L and the road surface (the left boundary line in FIG. 4B). Even when Yl) is heavily soiled, the other boundary line (right boundary line Yr in FIG. 4B) can be extracted, and based on this, the center boundary line Yc can be accurately identified. Therefore, in either case of FIG. 4A or FIG. 4B, the automatic guided system 1 can accurately drive the automatic guided vehicle 2 with the central boundary line Yc as a travel center.

  As described above, in the automatic guided system 1 according to the present invention, the robustness against the dirt and the defect of the guide line L is improved, and the automatic guided vehicle 2 can travel without being deviated from the central boundary line Yc.

  As mentioned above, although preferable embodiment of the unmanned conveyance system 1 which concerns on this invention was described, this invention is not limited to the said embodiment.

DESCRIPTION OF SYMBOLS 1 Automated guided vehicle 2 Automated guided vehicle 3 Car body 4 Wheel 5 Imaging means 6 Traveling control means A Imaging area C Center direction width D of vehicle body Dirt L Guiding line L 'Guiding line (conventional)
Lc The center line Ll in the width direction of the guide line Ll The left line portion Lr colored in the first color The right line portion T colored in the second color The vertical range t of the imaging region The extracted portion Yc of the guide line Center Boundary line (first boundary line)
Yl Left boundary line (second boundary line)
Yr right border (third border)
Wl, Wr boundary line (conventional)

Claims (2)

A guide line laid on the road surface and colored differently from the road surface;
An automatic guided vehicle having a vehicle body and an imaging unit attached to the vehicle body and imaging an imaging region including the guide line to generate image data of the imaging region;
The guide line is composed of two colors, a first color and a second color, which are different from each other, and the first boundary line generated by the difference in color between the first color and the second color is the guide color. It is colored to extend in the direction of laying the line,
The automatic guided vehicle extracts and specifies the first boundary line by performing image processing on the image data, and the predetermined position on the center line in the width direction of the vehicle body is specified on the first boundary line. An unmanned transport system that travels along the guide line so that
When the first boundary line is not extracted at all, or when the extracted first boundary line is less than a predetermined ratio, the automatic guided vehicle has the first of the guide lines extracted from the image data. A second boundary line caused by the difference between the color of the road surface and the color of the road surface, and a third boundary line caused by the difference between the second color of the guide line extracted from the image data and the color of the road surface Identifying the first boundary line based on both or one of the lines;
An unmanned transport system characterized by that. The induction line, AGV system of claim 1, characterized in that it is configured such that the first boundary line coincides with the widthwise center line of the guide line.

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