JP2020046835A - Unmanned conveyance system - Google Patents

Abstract

To provide an unmanned conveyance system which does not need to lay a guidance line.SOLUTION: The automatic guided vehicle system S includes an unmanned carrier 3, an image storage unit 4 which stores a guidance image G including a guidance line for guiding the unmanned carrier 3, and a projector 2 which is installed on a ceiling C and projects the guidance image G on a road surface. The unmanned carrier 3 includes an on-vehicle camera 32 which captures an image of the road surface R, a guidance line detection unit 36 which analyzes the image of the road surface R captured by the on-vehicle camera 32 and detects a guidance line in the guidance image G, and a steering control unit 35 which performs steering control based on the guidance line detected by the detection unit 36.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an unmanned transport system provided with an unmanned transport vehicle.

  In factories and warehouses, unmanned transport vehicles that can travel autonomously in transport operations are used. Various types of guidance systems are used in this type of automatic guided vehicle. For example, the automatic guided vehicle disclosed in Patent Literature 1 uses a guidance system that travels along a guidance line. Specifically, this automatic guided vehicle is provided with an imaging unit, uses the imaging unit to image a guide line laid on the road surface, and travels on the guide line based on the position of the imaged guide line. I do.

  The guide line is made of a tape affixed to the road surface, a paint applied to the road surface, or the like, and is colored differently from the road surface. However, since such a guide line is laid on a road surface, it is easy for dirt to adhere or peel off. Therefore, there is a problem that the automatic guided vehicle cannot recognize the guide line due to the adhesion and peeling of the guide line, and stops traveling.

  Therefore, for example, there is an automatic guided vehicle guidance system using electromagnetic induction that is not easily affected by the attachment or peeling of dirt (see Patent Document 2). According to this guidance system, the automatic guided vehicle detects the induced magnetic field of the tow path wire laid on the floor along the traveling route by a pickup coil provided on the vehicle body, and controls the steering motor based on the detected induced magnetic field. Thereby, it moves along the traveling route.

  However, laying the tow path wire on the floor is cumbersome. In addition, this guidance method has a problem that a tow path wire must be newly laid on the floor each time a layout in a factory or warehouse is changed.

JP-A-7-210246 JP-A-6-119036

  Therefore, an object of the present invention is to provide an unmanned transport system that does not need to lay a guide line.

In order to solve the above-described problems, an unmanned transport system according to the present invention includes:
Automatic guided vehicles,
An image storage unit that stores a guidance image including a guidance line that guides the automatic guided vehicle,
A projection unit that is installed above a ceiling or a wall and projects a guidance image onto a road surface,
Automated guided vehicles are
A first imaging unit for imaging a road surface;
A guide line detecting unit that analyzes a road surface image captured by the first image capturing unit and detects a guide line in the guide image;
A steering control unit that performs steering control based on the guidance line detected by the guidance line detection unit.

The unmanned transport system is preferably
A second imaging unit for imaging the direction projected by the projection unit,
A vehicle presence determination unit that determines whether an unmanned guided vehicle is present in a predetermined area based on an image captured by the second imaging unit;
A projection control unit that switches between a projection state and a non-projection state of the projection unit based on a determination result of the vehicle presence determination unit.

The unmanned transport system is preferably
A third imaging unit for imaging the direction projected by the projection unit,
A face direction determination unit that determines whether the direction of the face of a person at the projection destination of the projection unit is facing the direction of the projection unit based on the image captured by the third imaging unit;
When the face direction determination unit determines that the person's face is facing the direction of the projection unit, any part of the guidance image projected by the projection unit is determined based on the image captured by the third imaging unit. A part specifying unit that specifies whether the image is projected on a human face,
A brightness reduction unit that reduces the brightness of the part of the guidance image specified by the part specification unit.

The unmanned transport system is preferably
A fourth imaging unit that captures a guidance image projected on a road surface,
An image correction unit that corrects the guidance image based on the image captured by the fourth imaging unit.

The image correction unit is preferably
Based on each luminance of each color component of each pixel of the guidance image captured by the fourth imaging unit and each luminance of each color component of each pixel of the guidance image stored in the image storage unit, each pixel of the guidance image A correction coefficient calculation unit that calculates a correction coefficient of each color component of
A correction processing unit that corrects each luminance of each color component of each pixel of the guide image using the correction coefficient.

  ADVANTAGE OF THE INVENTION According to the unmanned transport system which concerns on this invention, an unmanned transport system which does not need to lay a guidance line can be provided.

FIG. 1 is a schematic diagram of an unmanned transport system according to a first embodiment of the present invention. It is a top view which shows the guidance image projected on the road surface. It is a functional block diagram of each composition with which the automatic guided vehicle of FIG. 1 is provided. FIG. 2 is a top view illustrating the automatic guided vehicle of FIG. 1 and a road surface on which a guidance image is projected. FIG. 2 is a functional block diagram of a control unit in FIG. 1. It is an outline figure of an unmanned conveyance system concerning a 2nd embodiment of the present invention. FIG. 7 is a functional block diagram of a control unit in FIG. 6.

<First embodiment>
A first embodiment of an unmanned transport system according to the present invention will be described with reference to the accompanying drawings. The directions X, Y, and Z in the front-rear direction, the left-right direction, and the up-down direction are based on the traveling direction of the automatic guided vehicle as shown in the accompanying drawings.

  FIG. 1 is a schematic diagram of the unmanned transport system S. In the unmanned transport system S, the control unit 1 controls the projector 2 to project the guidance image G on the road surface R. The automatic guided vehicle 3 is an unmanned forklift, and travels on a predetermined traveling route by being guided along a guidance line L in a guidance image G projected by the projector 2.

  The unmanned transport system S includes a control unit 1, a projector 2, an unmanned transport vehicle 3, and an image storage unit 4.

  The image storage unit 4 stores a guidance image G for guiding the automatic guided vehicle 3.

  The control unit 1 outputs the guidance image G stored in the image storage unit 4 to the projector 2 by wired or wireless communication.

  The projector 2 is installed on the ceiling C so as to face the road surface R, and projects the input guidance image G on the road surface R. The projector 2 corresponds to the “projection unit” of the present invention.

  As shown in FIG. 2A, in the guidance image G, a guidance line L having a certain width is arranged at the center, and the direction of the guidance line L indicates the direction in which the automatic guided vehicle 3 is guided. Further, the color of the guide line L is clearly different in lightness and saturation as compared with the two sides. The guidance image G is merely an example and is not limited to this. For example, only the guide line L of a color that is clearly different from the road surface R may be used as the guide image G.

<Automated guided vehicle 3>
As shown in FIGS. 1 and 3, the automatic guided vehicle 3 includes a vehicle body 31, a vehicle-mounted camera 32, a pair of left and right front wheels, a pair of left and right rear wheels, and one or both of a front wheel and a rear wheel. The vehicle includes a steering control unit 35 that controls the vehicle, a guidance line detection unit 36, a fork 37, and a mast 38.

  A part of the front surface of the vehicle body 31 is formed of a transparent member. The in-vehicle camera 32 is provided at a front upper side and a central position in the vehicle body 31 so as to face the road surface R through a transmission member. The position of the vehicle-mounted camera 32 is merely an example, and is not limited to this.

  As shown in FIG. 4, the vehicle-mounted camera 32 captures a predetermined imaging range T of the road surface R including the guidance image G, generates a road surface image, and outputs the road surface image to the guidance line detection unit 36. The in-vehicle camera 32 corresponds to the “first imaging unit” of the present invention.

  The guidance line detection unit 36 analyzes the input road surface image based on the saturation and brightness, and detects a guidance line L in the guidance image.

  The steering control unit 35 controls the steering of one or both of the front wheel 33 and the rear wheel 34 based on the guidance line L detected by the guidance line detection unit 36. Specifically, the steering control unit 35 performs feedback control of the steering angles of the wheels 33 and 34 so that the position of the guide line L is located at the center of the imaging range T. Thereby, the automatic guided vehicle 3 is guided along the guidance image G projected by the projector 2 and can travel on a predetermined traveling route.

  By the way, as shown in FIG. 2B, the road surface R may be stained or peeled off depending on the use condition, and in this case, a part of the guidance image G like the part A is not appropriately displayed. . Therefore, the control unit 1 analyzes the guidance image G projected on the road surface R, and corrects the guidance image G so as to correspond to such a road surface R. Hereinafter, a specific description will be given.

  As shown in FIG. 1, the unmanned transport system S further includes a lower camera 5. The lower camera 5 faces downward and is installed on the ceiling C adjacent to the projector 2. The lower camera 5 captures an image of the lower side, generates a lower image, and outputs the lower image to the controller 1. The lower camera 5 corresponds to the “fourth imaging unit” of the present invention.

  As shown in FIG. 5, the control unit 1 has an image correction unit 11. The image correction unit 11 includes a correction coefficient calculation unit 111 and a correction processing unit 112. The guidance image G stored in the image storage unit 4 is output to the correction coefficient calculation unit 111 and the projector 2 via the correction processing unit 112. The projector 2 projects the input guidance image G on the road surface R. The lower camera 5 captures the projected guidance image G, generates a road surface image, and outputs the road surface image to the correction coefficient calculation unit 111.

  The correction coefficient calculation unit 111 normalizes each luminance of each pixel of the guidance image G for each color component to generate input data D1, and also calculates each luminance of each pixel of the road surface image output from the lower camera 5 to each color component. The output data D2 is generated by normalizing the data. Next, the correction coefficient calculation unit 111 collates the input data D1 and the output data D2, and calculates a correction coefficient of each color component of each pixel for adjusting the luminance ratio between each pixel of the output data D2 to the input data D1. Then, the calculated correction coefficient is output to the correction processing unit 112.

  The correction processing unit 112 uses the calculated correction coefficient of each color component of each pixel to correct the luminance of each color component of each pixel of the projection image G1 to be projected, and generates a guidance image G2. Next, the correction processing unit 112 outputs the generated guidance image G2 to the projector 2 and outputs the generated guidance image G2 to the correction coefficient calculation unit 111. The projector 2 projects the input guidance image G2 on the road surface R. The lower camera 5 captures the projected guidance image G2, generates a road surface image, and outputs the road surface image to the correction coefficient calculation unit 111. The correction coefficient calculation unit 111 calculates the correction coefficient corresponding to the guidance image G2 as described above.

  As shown in FIG. 2 (c), by repeating this process, the finally projected guidance image G is displayed like an image projected on a monochrome screen. As described above, since the guide image G projected by the projector 2 is corrected as needed by the correction processing unit 112, the guide image G can be appropriately displayed so that the road surface R as the projection surface is partially stained. For this reason, the automatic guided vehicle 3 can appropriately detect the guide line L in the guide image G and travel along the guide line L.

<Second embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a schematic diagram of an unmanned transport system S according to the second embodiment of the present invention. The unmanned transport system S according to the second embodiment differs from the unmanned transport system S according to the first embodiment only in a part of the configuration of the control unit 1, and is common in other configurations. Therefore, a detailed description of the overlapping components will be omitted.

  As illustrated in FIG. 7, the control unit 1 further includes a face direction determination unit 12 and a part identification unit 13.

  The lower camera 5 captures an image below the projector 2 to generate a lower image, and outputs the lower image to the face direction determination unit 12 and the vehicle presence determination unit 15. The lower camera 5 corresponds to the “second imaging unit” and the “third imaging unit” of the present invention.

  The face direction determination unit 12 determines whether or not the face of the person H present below faces the direction P of the projector 2 based on the lower image. Specifically, the face direction determination unit 12 first recognizes the face of the person H by detecting characteristic portions of the face of the person H such as the eyes, the nose, and the mouth from the lower image. Estimate the orientation. Next, the face direction determination unit 12 determines whether or not the estimated face direction is in the direction P of the projector 2.

  When the face direction determining unit 12 determines that the face of the person H is facing the direction P of the projector 2, the partial identifying unit 13 guides the guided image projected by the projector 2 based on the lower image captured by the projector 2. It specifies which part of G is projected on the face of person H, and outputs the position of the specified part to brightness reduction unit 14.

  The brightness reduction unit 14 reduces the brightness of the portion of the guidance image G projected on the person H to a level that does not impair the eye health of the person H, based on the position input from the portion identification unit 13. The brightness lowering unit 14 outputs to the projector 2 the guidance image G in which the brightness has been partially reduced. The projector 2 projects the input guidance image G on the road surface R. Thereby, the unmanned transport system S prevents the person H indoors from directly viewing the projection light of the projector 2 continuously when the person H indoors has to check the direction of the ceiling C. Can be.

  The control unit 1 further includes a vehicle presence determination unit 15 and a projection control unit 16. The vehicle presence determination unit 15 determines whether or not the automatic guided vehicle 3 exists in a predetermined area based on the lower image. This predetermined area is an area including the periphery of the guidance image G projected on the road surface R by the projector 2.

  When the vehicle presence determining unit 15 determines that the automatic guided vehicle 3 does not exist in the predetermined area, the projection control unit 16 stops the projection of the projector 2 and the automatic guided vehicle 3 exists in the predetermined area. If so, the projector 2 restarts the projection. Therefore, when the automatic guided vehicle 3 is not within the projection range, the unmanned transport system S can save power by not projecting by the projector 2.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  (1) The projector 2 may be composed of a plurality of projectors 2 installed indoors. In this case, the plurality of guided images G may be simultaneously projected by the plurality of projectors 2 to simultaneously guide the plurality of automatic guided vehicles 3. Further, a plurality of guidance images G may be simultaneously projected by the plurality of projectors 2 to display a wide range of guidance images G on the road surface R.

  (2) The lower camera 5 includes, for example, a camera that captures the road surface R to generate a road surface R image and a camera that captures an image of the projection direction of the projector 2 to generate images of the automatic guided vehicle 3 and the person H. It may be configured. In this case, the camera that generates the images of the automatic guided vehicle 3 and the person H may generate an image for confirming the direction of the face of the human H and whether or not the automatic guided vehicle 3 exists in a predetermined area. If possible, it may not be installed adjacent to the projector 2, and may be installed, for example, on the upper part of a wall.

  (3) The projector 2 may be provided above a wall.

REFERENCE SIGNS LIST 1 control unit 11 image correction unit 111 correction coefficient calculation unit 112 correction processing unit 12 face direction determination unit 13 partial specification unit 14 brightness reduction unit 15 car presence determination unit 16 projection control unit 2 projector (projection unit)
3 Automated guided vehicle 31 Body 32 On-board camera (first imaging unit)
33 front wheel 34 rear wheel 35 steering control unit 36 guidance line detection unit 4 image storage unit 5 lower camera (second to fourth imaging units)
S Unmanned transport system L Guidance line G Guidance image C Ceiling R Road surface G Guidance image T Imaging range H Person

In order to solve the above-described problems, an unmanned transport system according to the present invention includes:
Automatic guided vehicles,
An image storage unit that stores a guidance image including a guidance line that guides the automatic guided vehicle,
A projection unit that is installed above a ceiling or a wall and projects a guidance image onto a road surface,
A road surface imaging unit that captures a guidance image projected on a road surface,
An image correction unit that corrects the guidance image based on the image captured by the road surface imaging unit ,
The projection unit further projects the guidance image corrected by the image correction unit on a road surface,
Automated guided vehicles are
A first imaging unit for imaging a road surface;
A guide line detecting unit that analyzes a road surface image captured by the first image capturing unit and detects a guide line in the guide image;
A steering control unit that performs steering control based on the guidance line detected by the guidance line detection unit.

The image correction unit is preferably
Based on each brightness of each color component of each pixel of the guide image captured by the road surface image unit and each brightness of each color component of each pixel of the guide image stored in the image storage unit, A correction coefficient calculation unit that calculates a correction coefficient for each color component;
A correction processing unit that corrects each luminance of each color component of each pixel of the guide image using the correction coefficient.

As shown in FIG. 1, the unmanned transport system S further includes a lower camera 5. The lower camera 5 faces downward and is installed on the ceiling C adjacent to the projector 2. The lower camera 5 captures an image of the lower side, generates a lower image, and outputs the lower image to the controller 1. The lower camera 5 corresponds to the “ road surface imaging unit” of the present invention.

REFERENCE SIGNS LIST 1 control unit 11 image correction unit 111 correction coefficient calculation unit 112 correction processing unit 12 face direction determination unit 13 partial specification unit 14 brightness reduction unit 15 car presence determination unit 16 projection control unit 2 projector (projection unit)
3 Automated guided vehicle 31 Body 32 On-board camera (first imaging unit)
33 front wheel 34 rear wheel 35 steering control unit 36 guidance line detection unit 4 image storage unit 5 lower camera (second to third imaging unit , road surface imaging unit )
S Unmanned transport system L Guidance line G Guidance image C Ceiling R Road surface G Guidance image T Imaging range H Person

Claims (5)

Automatic guided vehicles,
An image storage unit that stores a guidance image including a guidance line that guides the automatic guided vehicle,
A projection unit that is installed above a ceiling or a wall and projects the guidance image onto a road surface,
The automatic guided vehicle,
A first imaging unit for imaging the road surface;
A guidance line detection unit that analyzes the image of the road surface captured by the first imaging unit and detects the guidance line in the guidance image;
An unmanned transport system, comprising: a steering control unit that performs steering control based on the guidance line detected by the guidance line detection unit. A second imaging unit for imaging the direction projected by the projection unit;
A vehicle presence determination unit that determines whether the automatic guided vehicle is present in a predetermined area based on an image captured by the second imaging unit;
The unmanned transport system according to claim 1, further comprising: a projection control unit that switches between a projection state and a non-projection state of the projection unit based on a determination result of the vehicle presence determination unit. A third imaging unit that captures an image in a direction projected by the projection unit;
A face direction determination unit configured to determine whether a face of a person at a projection destination of the projection unit faces the direction of the projection unit based on an image captured by the third imaging unit;
When the face direction determination unit determines that the person's face is facing the direction of the projection unit, the guidance image projected by the projection unit is projected based on the image captured by the third imaging unit. A part specifying unit that specifies which of the parts is projected on the person's face,
The unmanned transport system according to claim 1, further comprising: a brightness reduction unit configured to reduce brightness of a portion of the guidance image specified by the portion specification unit. A fourth imaging unit that captures the guidance image projected on the road surface,
The unmanned transport system according to any one of claims 1 to 3, further comprising: an image correction unit configured to correct the guidance image based on an image captured by the fourth imaging unit. The image correction unit,
Based on each luminance of each color component of each pixel of the guidance image captured by the fourth imaging unit and each luminance of each color component of each pixel of the guidance image stored in the image storage unit, A correction coefficient calculation unit that calculates a correction coefficient of each color component of each pixel of the guidance image,
The unmanned transport system according to claim 4, further comprising: a correction processing unit configured to correct each luminance of each color component of each pixel of the guide image using the correction coefficient.

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