JP2022093887A - Unmanned carrier and unmanned carrier system - Google Patents

Abstract

To provide an unmanned carrier that can autonomously travel using an inexpensive image sensor even in an environment where disturbance light is incident in an indoor facility such as a storehouse, and an unmanned carrier system.SOLUTION: An unmanned carrier includes: an image sensor that captures an image of an object in the direction of travel; a drive unit that independently controls the drive of multiple wheels; a robot control unit that transmits a control command to the drive unit for autonomous driving along a travel path based on an environmental map; and a wireless communication unit. The robot control unit has: a function for constantly updating the environmental map and a route based on image information from the image sensor; a function for registering an image of a specific shape or pattern arranged along the travel path as a landmark image in association with coordinate information on the environmental map; a first current position estimation function for estimating a current position based on the image information from the image sensor and the environmental map; and a second current position estimation function for estimating a current position based on the coordinate information on the landmark image and the environmental map, when the image information from the image sensor includes the landmark image. A projection image is included as the landmark image.SELECTED DRAWING: Figure 1

Description

The present invention relates to an automatic guided vehicle having a map updating function by, for example, 3D-SLAM (3dimension Simultaneous Localization AND Mapping) and capable of autonomous traveling, and an automatic guided vehicle system including the automatic guided vehicle.

Conventionally, as a method for guiding an automated guided vehicle (AGV), for example, the following method is known.
(1) A method in which an automated guided vehicle is embedded in a driving path and detects radio waves from an inductive cable (2) A method in which an automated guided vehicle detects magnetism and reflected light by attaching an inductive tape to the traveling path (3) How to install a guide sign and the automatic guided vehicle recognizes the guide sign as an image

However, in these methods, it is necessary to install guidance equipment on the traveling path in advance.
Therefore, in recent years, research has been conducted on an automatic guided vehicle that recognizes obstacles with a sensor or the like and travels autonomously. The rule-based method, the (virtual) potential method, and the search method are mainly known as obstacle avoidance route generation methods. In Patent Document 1, a virtual potential method is adopted, and a plurality of partial maps constituting an environmental map of a moving area are created based on distance information and angle information with surrounding objects read from a laser range finder. An autonomous mobile device capable of performing is disclosed. In this autonomous mobile device, SLAM (Simultaneous Localization and Mapping) is used to estimate the self-position and create an environmental map in real time.

Japanese Unexamined Patent Publication No. 2010-92147

In the guidance method of (1) above, the cost of burying the guidance cable is high, and the travel path cannot be easily changed. In the guidance method of (2), if the guide tape installed on the road is damaged, guidance cannot be performed, so it is necessary to replace the guide tape on a regular basis. In an environment where the flow line of an automatic guided vehicle and the flow line of a forklift overlap, such as in a warehouse, there is a problem that the replacement span of the guide tape becomes shorter than usual.

In the guidance method of (3) above, inconsistency occurs in the created environmental map due to the accumulation of measurement errors, and in particular, when creating a circular environmental map, the start part and the end part do not match. The problem of this (circular route problem) has been pointed out. In addition, it has been pointed out that if the layout around the track is changed, it is necessary to recreate the entire environmental map. Therefore, in Patent Document 1, by dividing the environmental map into a plurality of partial maps and managing them, the range of measurement error is limited to the partial map, and the range that needs to be recreated when the layout is changed is limited to the partial map unit. Has been proposed.
However, in an environment where manned vehicles and workers work in the same space, the layout in the work space changes constantly, so there is a problem that the accuracy of self-position estimation deteriorates due to unexpected environmental changes. There is. There is also a need to minimize the system setting changes required when changing the layout in the warehouse.

By the way, as a means for grasping surrounding objects, there is a need to use an inexpensive sensor instead of an expensive laser range finder (for example, LiDAR (Light Detection and Ranging)). It is conceivable to use an inexpensive image sensor such as a stereo camera as an alternative method, but if ambient light is incident on the field of view of the automatic guided vehicle, it will be temporarily impossible to grasp surrounding objects, and the automatic guided vehicle will stop. Occurs. There is a problem that it is difficult to construct an automatic guided vehicle using a stereo camera in an environment where ambient light is constantly incident from an arrival / shipment place that is in contact with the outdoors, such as a warehouse.

Therefore, an object of the present invention is to provide an automatic guided vehicle and an automatic guided vehicle system that can solve the above problems.

The unmanned carrier of the present invention has an image sensor that captures an image of an object on the traveling direction side, a drive unit that independently controls the drive of a plurality of wheels, and a control command for autonomously traveling along a travel path based on an environmental map. A robot control unit and a wireless communication unit are provided, and the robot control unit constantly updates the environment map and the route based on the image information from the image sensor, and along the travel path. A function to register an image of a specific shape or pattern placed as a landmark image in association with the coordinate information on the environmental map, and feature point recognition in the image information from the image sensor, which is currently compared with the environmental map. A first current position estimation function that estimates the position, and a second current position estimation function that estimates the current position based on the coordinate information of the landmark image when the image information from the image sensor includes a landmark image. The landmark image is characterized by including a projected image.
In the automatic guided vehicle, the drive unit has a function of transmitting rotation information of the plurality of wheels to the robot control unit as odometry information, and the robot control unit has the odometry information and the current position information stored immediately before. It may be characterized by having a third current position estimation function for estimating the current position based on the above.
In the automatic guided vehicle, the robot control unit has a function of continuously generating a composite image in which a virtual image is added to image information from an image sensor, and a function of performing running control based on the virtual image included in the composite image. It may be characterized by that.
In the unmanned carrier, the projected image is an image of a line, a pattern, an artificial code, a character string, a logo, or a character projected on a floor surface, a wall surface, and / or a ceiling, and the robot control unit. May be characterized by having a function of traveling control based on the projected image.
The automatic guided vehicle may be characterized by having a line follow function for traveling along a line projected along the traveling path.
In the automatic guided vehicle, the landmark image may include an image of an artificial code including a two-dimensional code.

The automatic guided vehicle system of the present invention includes the automatic guided vehicle and a landmark image projection device that projects a line, a pattern, an artificial code, a character string, a logo, or an image of a character along the traveling path. It is an automatic guided vehicle system equipped.
In the automatic guided vehicle system, the landmark image projection device is a line, a pattern, an artificial code, a character string, a logo, or a character on the floor, the wall surface, and / or the ceiling along the traveling path. It may be characterized by having a function of projecting an image.
In the automatic guided vehicle system, the landmark image projection device has a function of projecting a line, a pattern, an artificial code, a character string, a logo, or an image of a character on a passage portion that is a boundary between a travel path and a work section. It may be characterized by being prepared.
The automatic guided vehicle system may be characterized in that the landmark image projection device is provided with a server that transmits a projection command for projecting a specific image.
In the automatic guided vehicle system, the projection command is a first image for causing the automatic guided vehicle to perform a first travel control and a second image for causing the automatic guided vehicle to perform a second travel control. It may be characterized by including a projection command for projecting an image.
In the unmanned carrier system, the server transmits a projection command for projecting the first image in the first time zone, and transmits a projection command for projecting the second image in the second time zone. It may be characterized by that.

According to the present invention, it is possible to provide an automatic guided vehicle and an automatic guided vehicle system that can autonomously travel using an inexpensive image sensor even in an environment where ambient light is incident in an indoor facility such as a warehouse. In addition, it is possible to easily respond to layout changes in the warehouse.

It is a block diagram of the automatic guided vehicle system which concerns on embodiment. It is a top view of the automatic guided vehicle which concerns on embodiment. It is a side view of the automatic guided vehicle which concerns on embodiment. It is a top view for demonstrating the traveling path of the warehouse which concerns on embodiment. It is a figure explaining the triangular cone to which the AR marker which concerns on embodiment is attached, and the color tape attached to the wall. It is a figure for demonstrating the wall line recognition area and the floor line recognition area in this embodiment. It is a figure for demonstrating the traveling control method using the floor guidance line provided on the floor surface. It is a figure for demonstrating the traveling control method using the wall guide line provided on the wall. It is a figure for demonstrating the traveling control method using the ceiling guidance line provided on the ceiling. It is a flowchart of route correction during traveling. It is a flowchart of the present position acquisition which also used the complementary information. It is a figure for demonstrating the composite image generation function which dynamically generates the composite image which added the virtual image to the captured image.

Hereinafter, the system configuration of the embodiment of the present invention will be described, and then the procedure of the warehousing / delivery work will be described as an example of the transport work method of the present invention.
<System configuration>
The automatic guided vehicle system of the embodiment includes an RM server 1, a WMS server 2, a management terminal 3, a handy terminal 4, a wireless LAN base unit 5, a basket car 6, a landmark image projection device 7, and the like. It is configured to include a plurality of automatic guided vehicles 10. The handy terminal 4, the wireless LAN base unit 5, the basket car 6, the landmark image projection device 7, and the plurality of automatic guided vehicles 10 are installed in the work place of an indoor facility such as a warehouse.

The RM server 1 is a server that makes it possible to manage the automatic guided vehicle 10, and is constructed by installing RM software and database software in a server device including a CPU and a storage device. This RM software includes a transport vehicle management unit 1a, a work adjustment unit 1b, a work location management unit 1c, and a billing information management unit 1d as software modules that realize main functions.
The automatic guided vehicle management unit 1a manages work location information in which the automatic guided vehicle 10 is arranged and operation information of the automatic guided vehicle 10. In the automatic guided vehicle management unit 1a, the vehicle ID of the automatic guided vehicle 10 and the work place ID to be worked are linked and managed.
The work adjustment unit 1b manages the operating time of a plurality of automatic guided vehicles 10. The work adjustment unit 1b manages the vehicle ID of the automatic guided vehicle 10 in association with the work place ID to be operated, and serves as input data for calculating billing information. In some cases, a plurality of automatic guided vehicles 10 may be operated in the same space in the same building, or only one of them may be operated.
The work place management unit 1c manages the basic map for each work place and transmits the basic map to the automatic guided vehicle 10. In the basic map, passable courses and prohibited areas are set. The basic map of the work place may not be managed by the RM server 1, but may be managed by the automatic guided vehicle 10 and the management terminal installed in the work place.
The billing information management unit 1d acquires the operation information of the automatic guided vehicle 10 from the transport vehicle management unit 1a, refers to the charge table for each client, and calculates the billing information.
The projection device management unit 1e transmits a projection command for projecting a specific image onto a specific landmark image projection device 7. The projection device management unit 1e also has a function of transmitting a projection command for projecting different images in the first time zone and the second time zone.

The WMS server 2 is a server that makes it possible to realize a warehouse management system, and is constructed by installing WMS software and database software in a server device including a CPU and a storage device. This WMS software includes an inventory management unit 2a and an order processing unit 2b as software modules that realize main functions.

The inventory management unit 2a updates the inventory database that manages the product ID, the address of the storage destination, the status, and the like. In addition, a function of assigning a storage address according to the warehousing information received from the management terminal 3, a function of sending a warehousing instruction to the handy terminal 4 and an automatic guided vehicle 10, a function of warehousing items, the status of delivery status, and the like. It has a function to manage.
The order processing unit 2b updates the order database that manages the order information received from the management terminal 3. The order processing unit 2b sends a delivery instruction to the handy terminal 4 and the automatic guided vehicle 10 based on the order information, and when the delivery information is received from the handy terminal 4, the status of the order is updated to complete. In addition, it has an allocation function to reserve inventory according to an order, and if you allocate by the number of orders in inventory according to one order, the quantity can not be reserved from other orders, so inventory is secured. Will be done.

The landmark image projection device 7 is, for example, a laser beam irradiation device or a projector, and a plurality of the landmark image projection devices 7 are installed on the ceiling, wall surface, or floor surface along the traveling path in the warehouse. The landmark image projection device 7 is configured to be communicable with the RM server 1, and based on a projection command from the RM server 1, an image of a specific shape or pattern that can be used as a landmark image is displayed on the floor surface, wall surface, or. Project on the ceiling. Images of specific shapes and patterns projected by the landmark image projection device 7 include, for example, lines including dotted lines, polygons including circles and ellipses, triangles, geometric patterns, artificial codes, character strings, company logos, and the like. The character is illustrated. An image different depending on the time zone may be projected on the landmark image projection device 7. The landmark image projection device 7 of the embodiment includes a swivel device, and can change the projection position based on a command from the RM server 1.
As shown in FIG. 1, the automatic guided vehicle 10 includes a robot control unit 11, a display unit 12, a wireless communication unit 13, a speaker 14, a power supply unit 15, a drive system (21 to 23), and a sensor group. (31 to 33) are provided.

As shown in FIGS. 2 and 3, the drive system (21 to 23) of the automatic guided vehicle 10 is arranged on the lower surface side of the base 16, and the other robot control units 11 and the like are arranged on the upper surface side of the base 16. Has been done. The wheels 19 are single wheels having no drive device and are arranged on the lower surface of the base 16 via a rotary table 18.
A gate-shaped frame 17 is provided on the traveling direction side of the base 16, and an arm for attaching the display unit 12, an emergency stop button 24, and an image sensor 33 are suspended and fixed to the upper pillar of the frame 17. A fixing tool is provided for this purpose.
On the side opposite to the traveling direction of the base 16, a connecting portion 41 provided with a locking pillar 42 is arranged. In the illustrated example, the locking plate 53 of the trailer 50 capable of towing the container is attached to the locking pillar 42. The trailer 50 is a non-self-propelled trolley provided with a block-shaped body portion 51, a long plate-shaped support portion 52, and a pair of wheels 54a and 54b. The trailer 50 can be further connected to other trailers.

The robot control unit 11 is a computer on which transport software configured using ROS (Robot Operating System), which is a standard platform for robot development, is operated, and is a map management unit 111, an operation management unit 112, and a route generation. A unit 113, a sensor management unit 114, and a virtual image generation unit 115 are provided.
The map management unit 111 has a map update function by 3D-SLAM (3dimension Simultaneous Localization AND Mapping). The environmental map updated by the map update function is composed of a basic map for unchanged parts such as a floor map and a basic passage, and a plurality of partial maps. The map management unit 111 grasps the position and shape information of objects such as basket cars and packing boxes that are constantly changed based on the signals from the sensor group (31 to 33), and while traveling, the map management unit 111 is a partial map around itself ( Peripheral map) is updated in real time.

The operation management unit 112 controls the drive system (21 to 23) of the automatic guided vehicle 10 based on the entry / exit instruction to enable autonomous traveling. Information on the amount of rotation of the wheels 23a and 23b obtained by the encoder provided on the axle is stored as odometry information. The operation management unit 112 has a function of estimating its own position without communicating with the RM server 1 by using image information, odometry information, an environmental map, and observation data of sensor groups (31 to 33) (No. 1). Current position estimation function of 1). Here, a 6-axis sensor may be separately provided, and information from the 6-axis sensor may also be used together. For the estimation of the self-position, a known estimation method (for example, the Monte Carlo method) can be used. It also has a line follow function, which will be described later. When a plurality of automatic guided vehicles 10 are driven on the same travel path, a function of exchanging their own positions with each other and ensuring a constant inter-vehicle distance may be provided. The operation management unit 112 has a second current position estimation function that estimates the current position based on the coordinate information of the landmark image when the image information from the image sensor includes the landmark image described later.
The route generation unit 113 uses the environment map stored in the storage device of the robot control unit 11 to generate a route for autonomous traveling without communicating with the RM server 1. The storage address of the product, which is the warehousing / delivery position, is managed by the inventory management unit 2a in association with the product ID. The cargo handling position for receiving and delivering cargo from a transport vehicle such as a truck is managed by the address on the basic map. When the warehousing / delivery instruction is issued, the route generation unit 113 generates a route (global route) from the cargo handling position to the warehousing / delivery position based on the basic map and the partial map, and it is necessary to update the partial map while traveling. The peripheral route (local route) of the automatic guided vehicle 10 is corrected according to the above.

The sensor management unit 114 detects observation signals from the front sensors (31a to 31c), side sensors (32a, 32b), and the image sensor 33, and transmits them to the map management unit 111, the operation management unit 112, and the like. The three front sensors (31a to 31c) provided in front are distance sensors (for example, ultrasonic sensors), and detect an object existing in front in a range of, for example, 180 degrees or more. The two side sensors (32a, 32b) provided on the sides are distance sensors (for example, ultrasonic sensors), and detect objects existing on the sides in a range of, for example, 120 degrees or more. When five sensors (31a to 31c, 32a, 32b) provided in the front and side detect an obstacle (including a person), the operation management unit 112 that receives the detection information from the sensor management unit 114 receives the detection information from the obstacle management unit 112. If it is difficult to avoid the problem, control is performed to suspend the vehicle.

The virtual image generation unit 115 has a composite image generation function that dynamically generates a composite image in which a virtual image is added to the captured image of the image sensor 33. For example, by dynamically generating a composite image with an image of a virtual line added, the line follow function described later can be executed based on the added virtual line, or an image with a mark indicating a turning position is added. By dynamically generating the combined image, it is possible to control the direction change based on the added virtual mark. Further, in an environment where ambient light is incident, traveling control can be performed by dynamically generating a composite image to which a virtual landmark image is added. In these cases, it is premised that the current position information held by the operation management unit 112 is correct, so supplementary information using artificial code information such as an AR marker with known coordinates, a QR code (registered trademark), or a barcode is used. It is preferable to use it in combination to acquire the current position.

12A is an image captured by the image sensor 33, FIG. 12B is a composite image in which a virtual image is added to the image captured by the image sensor 33, and FIG. 12C is a schematic plan view of FIG. 12B.
In the composite image shown in FIG. 12B, the virtual guidance line 81 and the virtual control sign 82 are added to the captured image of the image sensor 33. Based on the added virtual guidance line 81 and the virtual control sign 82, the operation management unit 112 performs traveling control. For example, it discloses that the virtual guidance line 81 is line-followed so as to be located at the center of the base 16 and the traveling control for turning 90 degrees to the right at the virtual control sign 82 is performed. When the landmark image in the captured image changes due to the traveling of the automatic guided vehicle 10, the current position of the automatic guided vehicle 10 is corrected in real time, so that the drawing positions of the virtual guidance line 81 and the virtual control sign 82 are inaccurate. Even if there is, the drawing position is corrected as the automatic guided vehicle 10 travels.

The image sensor 33 is composed of a stereo camera that captures two-dimensional images arranged at a distance. The stereo camera may be configured by fixing two independent cameras, or may be configured by integrally including two lens mechanisms and a shutter mechanism. The image sensor 33 is preferably configured by a color camera so that it can recognize color information. The image sensor 33 is attached to the front side of the base 16 and captures a two-dimensional image in front of the automatic guided vehicle 10 and transmits it to the map management unit 111.
The map management unit 111 generates a three-dimensional image having distance information based on the captured image of the image sensor 33. In addition, the map management unit 111 also has a function of registering an image of an object having a specific shape or pattern or an image of a specific shape or pattern projected on a floor surface or a wall surface as a landmark image in association with coordinates. is doing. As landmarks made of tangible objects, protective signs such as triangular cones (safety cones) and columns can be registered, color tapes and hanging signs can be registered, and AR markers and QR codes (registered trademarks) can be registered. ) And other two-dimensional codes and information signs such as emergency exit plates can also be registered. In addition, an image of a specific shape or pattern projected from the landmark image projection device 7 onto the floor surface, wall surface, or ceiling can be used as a landmark. The projection of the image from the landmark image projection device 7 can also be performed at the designated coordinates. A server for managing landmark images may be installed in the work place or in the cloud, and the landmark information (image and coordinate information) may be shared by a plurality of automatic guided vehicles 10 arranged in the work place. Protective signs and information signs are preferably colored in a color that contrasts well with the background of the work area.

The display unit 12 is composed of a touch screen and also serves as an information input unit. In the embodiment, the display unit 12 is configured by a tablet-type terminal running a program capable of communicating with the robot control unit 11. The recommended route created by the route generation unit 113 is displayed on the display unit 12. When the worker approves the route, the route generation unit 113 converts the approved route into array data. If the recommended route is not preferable, a route change instruction can be issued, and another route created by the route generation unit 113 is displayed.
The wireless communication unit 13 enables bidirectional communication with the handy terminal 4 and the RM server 1 by a wireless LAN (for example, Wi-Fi). The communication module of the handy terminal 4 and the RM server 1 may be configured by a separate module, and the communication with the RM server 1 may be configured to be performed by an LPWA (Low Power Wide Area Network).
The speaker 14 is composed of a general-purpose speaker, and a melody for notifying that the automatic guided vehicle 10 is running is sounded while the automatic guided vehicle 10 is running. When the automatic guided vehicle 10 is stopped due to an abnormality, an alarm notifying the abnormality is sounded from the speaker 14. It should be noted that the alarm may not be sounded at the time of abnormal stop, and an image for notifying the abnormality may be displayed on the display unit 12, or a configuration for notifying the abnormality may be adopted by a separately provided indicator lamp.
The power supply unit 15 is provided with a rechargeable secondary battery, and makes it possible to run the automatic guided vehicle 10 cable-free. In addition to the contact-type charging device, the power supply unit 15 is provided with a power receiving device on the bottom surface portion or the side surface portion that enables non-contact charging by locating the automatic guided vehicle 10 in the charging area. The non-contact charging is not an indispensable configuration, and may be configured to include only a contact-type charging device.

The drive system (21 to 23) includes a drive control device 21, drive devices 22a and 22b, and wheels 23a and 23b.
The drive control device 21 is a computer that independently controls the drive of each of the drive devices 22a and 22b based on an instruction from the robot control unit 11. The automatic guided vehicle 10 is changed in direction by changing the rotational angular velocity of the wheel 23a by the drive device 22a on the right side and the rotational speed of the wheel 23b by the drive device 22b on the left side.
The drive devices 22a and 22b are configured to include general-purpose motors such as direct current (DC) motors, alternating current (AC) motors, motors with encoders, geared motors, etc., and the wheels 23a and 23b can be rotated at arbitrary rotational angular speeds. .. The drive devices 22a and 22b can carry a load of 500 kg at a speed of, for example, 50 m / min or less. Unlike the embodiment, a steering device for steering the wheels 23a and 23b may be separately provided in the drive device. In this case, the odometry information described above includes steering angle information.
In the embodiment, tires suitable for running on a floor surface coated with epoxy resin or the like are used for the wheels 23a and 23b. The diameter, width, and presence / absence of the tread pattern of the wheels 23a and 23b can be optimally selected according to the weight of the article to be transported and the condition of the floor surface.

The management terminal 3 is a terminal such as a notebook PC, a desktop PC, or a tablet, and is used for managing the RM server 1 and the WMS server 2. It may be possible to transmit a projection command directly from the management terminal 3 to the landmark image projection device 7.
The handy terminal 4 is a mobile terminal used for reading a barcode during picking work. The handy terminal 4 has a display unit consisting of a liquid crystal screen or the like, a storage unit composed of a storage device or the like, a control unit composed of a processor or a built-in clock, an operation unit composed of buttons or the like, a bar code reader unit, and wireless communication. It has a unit and a secondary battery. In the present embodiment, the operation unit is provided separately from the display unit, but the display unit may be configured with a liquid crystal touch screen capable of inputting information. The handy terminal 4 of the preferred embodiment can wirelessly communicate with the robot control unit 11 of the automatic guided vehicle 10.
The wireless LAN base unit 5 is arranged on the floor of the work place, and an environment is provided in which access to the wireless LAN (for example, Wi-Fi) is possible at any place on the floor.

FIG. 4 is a plan view for explaining a traveling path of the warehouse according to the embodiment. In the figure, the shaded area is the running path. The floor line 71 is partially projected by the landmark image projection device 7 at the boundary between the travel path and the work section on the floor surface. For places where it is difficult to project the floor line 71, the floor line 71 may be formed by color tape (eg, tiger-patterned tape) or painting. In the figure, the boundary line 72 shown by the dotted line is the boundary between the traveling path and the working section, and indicates a portion that becomes a passage for a person or a forklift. It is preferable that the landmark image projection device 7 projects an image having a different color, a different shape, or a different pattern from the floor line 71 on the boundary line 72. In the embodiment, the floor line 71 and the boundary line 72 can be distinguished by forming the floor line 71 and the boundary line 72 with lines of different colors. The projected boundary line 72 does not deteriorate even when a person or a forklift passes through it, and contributes to the person's visual recognition of the work space. Further, by using the boundary line 72 as a landmark image, the landmark information in the travel path is increased, so that the accuracy of autonomous travel can be improved. Further, the floor guidance line 76, which will be described later, may be projected onto the main portion of the travel path by the landmark image projection device 7.

As shown in FIG. 5, a color tape (for example, a tiger) for calling attention to an operator at a height reflected on an image sensor 33 of a wall along a traveling path (for example, a height lower than the height of a person). Pattern tape) 75 is partially attached. Instead of the color tape 75, a color line may be formed by painting. The wall guidance line 77 and the ceiling guidance line 78, which will be described later, are projected by the landmark image projection device 7 at locations necessary for traveling control.

In the illustrated example, any of areas A, B and C can be set as the start and finish points. Illustrated by reference numeral 73 is a support column as high as the waist, and the support column is colored (for example, a tiger-patterned tape). Illustrated by reference numeral 74 is a traffic cone (registered trademark, hereinafter omitted). As shown in FIG. 5, a two-dimensional code 79 such as an AR marker is attached to a part of the color cone 74. Color tape 75 is attached to the corners of the pillars in contact with the running path in the vertical direction. The color tape 75 may be replaced by painting, or an image of a specific shape or pattern may be projected by the landmark image projection device 7. The columns 73, the color cone 74 and the color tape 75 also function as markers for workers. In this way, since a sign for workers is installed in the space where the automatic guided vehicle 10 travels, the automatic guided vehicle 10 uses this as feature point information and uses it to grasp the current position. is doing.

The automatic guided vehicle 10 according to the present embodiment also has a function of detecting guidance lines 76 and 77 provided on the floor or wall and autonomously traveling. Specifically, the automatic guided vehicle 10 first includes a floor guidance line 76 formed on a traveling path on a floor surface and a wall guidance line 77 formed on a wall surface in an image captured by an image sensor 33. recognize. Here, FIG. 6 shows a method of recognizing in the present embodiment whether the guidance line detected in the region in the captured image is a line formed on the floor surface or a line formed on the wall surface. It is a figure for demonstrating. As shown in FIG. 6, in the present embodiment, the operation management unit 112 of the automatic guided vehicle 10 sets the area below the center of the screen of the captured image as the floor guidance line recognition area, and sets the area below the center of the screen of the captured image and The area excluding the upper part of the screen is set as the wall guidance line recognition area. Then, when the operation management unit 112 detects a line image having specific color information in the floor guidance line recognition region, the operation management unit 112 recognizes that the line is the floor guidance line 76 formed on the floor surface, and the floor guidance Travel control is performed based on the line 76. Further, when the operation management unit 112 detects a line image having specific color information in the wall guidance line recognition region, the operation management unit 112 recognizes that the line is the wall guidance line 77 formed on the wall surface, and recognizes that the line is the wall guidance line 77. Travel control based on 77 is performed.
As shown in FIG. 6, when both the floor guide line 76 formed on the running path of the floor surface and the wall guide line 77 formed on the wall surface were detected, both lines 76 and 77 were detected. It is also possible to perform travel control, to have a specific vehicle perform a first travel control based on the floor guidance line 76, and another vehicle to perform a second travel control based on the wall guidance line 77. You can also.

FIG. 7 is a diagram for explaining a traveling control method using the floor guidance line 76 formed on the floor surface. For example, when the automatic guided vehicle 10 detects the floor guidance line 76 in the traveling path on the floor surface, for example, as shown in FIG. 7A, the floor guidance is on the center line in the longitudinal direction of the detected floor guidance line 76. A line follow function for controlling traveling can be provided so as to travel along the line 76. Alternatively, the automatic guided vehicle 10 regards the detected floor guide line 76 as the end of the passage, for example, as shown in FIG. 7B, so as not to exceed the floor guide line 76 or to be constant from the floor guide line 76. Travel control can be performed so that the vehicle travels a distance away. Here, the floor line 71 or the boundary line 72 may be used as the floor guidance line 76.
FIG. 8 is a diagram for explaining a traveling control method using the wall guide line 77 formed on the wall surface. Further, when the automatic guided vehicle 10 detects the wall guidance line 77 on the wall surface along the traveling path, it is constant from the detected wall guidance line 77 as shown in FIGS. 8A and 8B. Travel control can be performed so as to travel along the wall guidance line 77 at a position separated by a distance. Here, the color tape 75 attached to the wall may be used as the wall guide line 77.

Further, in the present embodiment, the automatic guided vehicle 10 has a function of registering an image of a color tape attached to the ceiling, a hanging signboard, a beam, a lighting fixture, etc. suspended from the ceiling as a landmark image in association with coordinates. In addition, it also has a function to detect the guidance line provided on the ceiling and drive autonomously.
FIG. 9 is a diagram for explaining a traveling control method using the ceiling guidance line 78 provided on the ceiling. As shown in FIG. 9, the operation management unit 112 of the automatic guided vehicle 10 sets the area on the upper center of the screen of the captured image as the ceiling recognition area. When the operation management unit 112 detects a line image in the ceiling recognition area, the operation management unit 112 recognizes that the line is a ceiling guidance line 78 formed on the ceiling, and controls traveling based on the ceiling guidance line 78 formed on the ceiling. I do. For example, the automatic guided vehicle 10 can be provided with a line follow function that controls traveling so as to travel along the ceiling guidance line 78 on the center line in the longitudinal direction of the detected ceiling guidance line 78. It is also possible to combine traveling based on the ceiling guidance line 78 with landmark information on the ceiling (for example, a hanging signboard suspended from the ceiling) to control traveling so that the hanging signboard travels to a position directly above. .. In particular, in a facility such as a hospital with a low ceiling, it is useful to perform traveling control based on the ceiling guidance line 78 formed on the ceiling.

The floor line recognition area and the wall line recognition area shown in FIG. 6 and the ceiling recognition area shown in FIG. 9 are examples, and the range can be changed as appropriate. Further, when the unmanned carrier 10 estimates the current position from each line (71, 72, 76 to 78) as feature point information, as described above, the unmanned carrier 10 recognizes the line recognized in the floor line recognition area of the captured image. It is recognized as a floor line 71, a boundary line 72 or a floor guide line 76 formed on the floor surface, and a line recognized in the wall line recognition area of the captured image is recognized as a wall guide line 77 formed on the wall surface, or is imaged. By recognizing the line recognized in the ceiling recognition area of the image as the ceiling guidance line 78, the current position can be estimated.

Further, in the above-mentioned example, in order to perform highly accurate and stable running control in a running path such as a narrow passage or a curve, a support column 73, a color cone 74, a color tape 75, a signboard attached to the ceiling (not shown), and the like. Is illustrated as a configuration for estimating the current position by using It can also be an estimated configuration. For example, in FIG. 4, reference numeral D is a charging area, reference numeral E is an entrance / exit, and reference numeral F is a loading / unloading place. In the charging area of reference numeral D, a power transmission device (shown) for non-contact charging is arranged. However, in the charging area, charging cannot be performed unless the automatic guided vehicle 10 is guided with an accuracy on the order of cm. Therefore, a floor guidance line 76 for guiding the automatic guided vehicle 10 to the power transmission device is attached. The floor guide line 76 may be created by color tape, may be created by painting, or may be projected by the landmark image projection device 7. Here, the color tape is sufficient as long as it is a visible tape, and includes a translucent tape and a tape with a pattern. Further, the floor guide line 76 may be a line composed of a dotted line.
The operation management unit 112 has a line follow function that guides the automatic guided vehicle 10 along the line when the image sensor 33 detects the line image. As an implementation form of the line follow function, for example, it is disclosed that traveling control is performed by extracting preset color information and recognizing the shape of the line. With this line follow function, it is possible to guide the automatic guided vehicle 10 so that the power receiving device is located above the power transmission device with an accuracy on the order of cm.
The cargo handling place F is also a place where a transport vehicle such as a truck arrives and departs, and is incident with ambient light.

The automatic guided vehicle 10 is traveling while correcting the route at regular intervals. FIG. 10 is a flowchart of route correction during traveling.
STEP601: The robot control unit 11 acquires image information in the traveling direction and its surroundings by an image sensor, and recognizes feature points in the image information. The details of feature point recognition will be described later.
STEP602: The robot control unit 11 proceeds to STEP603 when the current position can be acquired, and proceeds to STEP606 when the current position cannot be acquired.

STEP603: The robot control unit 11 updates the acquired partial map corresponding to the current position based on the image information.
STEP604: The robot control unit 11 determines whether the correction of the set route is necessary, proceeds to STEP605 if necessary, and returns to STEP601 if it is not necessary.
STEP605: The robot control unit 11 corrects the set route and stores it in the storage device.

STEP606: The robot control unit 11 acquires the odometry information from the storage device, and calculates the current position based on the current position information and the odometry information stored immediately before in the storage device.
STEP607: The robot control unit 11 proceeds to STEP608 when the current position can be acquired, and proceeds to STEP609 when the current position cannot be acquired.
STEP608: The robot control unit 11 updates the acquired partial map corresponding to the current position based on the image information.
STEP609: Stop the automatic guided vehicle 10, display a screen notifying the abnormality on the display unit 12, or sound an alarm notifying the stop from the speaker 14.
STEP610: The robot control unit 11 determines whether the correction of the set route is necessary, proceeds to STEP605 if necessary, and returns to STEP601 if it is not necessary.

A supplementary explanation will be given regarding feature point recognition in STEP601. In a warehouse where objects installed around it are constantly changing, feature points are extracted in a form that includes objects that are constantly moving, such as basket cars and merchandise boxes, so false positives are likely to occur. Therefore, in the embodiment, when the current position cannot be acquired by the feature point extraction based on the image information, the current position is acquired by using the complementary information such as the landmark information and the artificial code information together. FIG. 11 is a flowchart of the current position acquisition using the complementary information.

STEP7011: The robot control unit 11 recognizes feature points in the image information of the traveling direction and its surroundings acquired by the image sensor, compares it with the basic map and the partial map, and tries to acquire the current position.
STEP702: If the current position can be acquired, the process proceeds to STEP706, and if the current position cannot be acquired, the process proceeds to STEP703.
STEP703: Based on the result of feature point recognition for the acquired image information, the complementary information registered in advance in association with the coordinates is detected. For example, the coordinate information of a specific AR marker extracted from the image information is read out, and the current position is calculated based on the position and size of the AR marker in the image.
STEP704: If the current position can be acquired, the process proceeds to STEP706, and if the current position cannot be acquired, the process proceeds to STEP705.
STEP705: The automatic guided vehicle 10 is stopped, a screen notifying the abnormality is displayed on the display unit 12, or an alarm notifying the stop is sounded from the speaker 14.
STEP706: The robot control unit 11 stores the acquired current position in the storage device.

The automatic guided vehicle 10 of the embodiment described above can autonomously travel based on a projected image, peripheral image information, and an inexpensive obstacle sensor without installing a guide cable or a guide tape. Therefore, it is possible to construct an automatic guided vehicle even in an existing warehouse with a minimum of capital investment.

Further, by changing the projection position of the projected image of the landmark image projection device 7, it is possible to easily cope with the layout change in the warehouse. In addition, by using the projected virtual landmark image together, it is possible to improve the acquisition accuracy of the current position even in an environment where ambient light is incident.

Although the preferred embodiment of the present invention has been described above, the technical scope of the present invention is not limited to the description of the above embodiment. Various changes and improvements can be added to the above-described embodiments, and those in which such changes or improvements have been made are also included in the technical scope of the present invention.
In the example of the embodiment, the configuration in which the automatic guided vehicle 10 receives the warehousing information and the order information from the WMS server 2 has been described. However, an automatic guided vehicle system that does not cooperate with the WMS server 2 may be constructed, for example, the handy terminal 4. Or, the warehousing / delivery instruction may be transmitted to the automatic guided vehicle 10 from the management terminal installed at the work place.
Further, it is not necessary to acquire the current position in the priority order described with reference to FIG. 10, and the robot control unit 11 can set an arbitrary priority as to what information is used to prioritize the acquisition of the current position. Is. For example, the priority of the distance sensor or the line follow function may be prioritized to the acquisition of the current position based on the information from the image sensor 33.

Further, in the above-described embodiment, the warehouse is exemplified as an indoor facility in which GPS cannot be used, but the present invention is not limited to the use in the warehouse, and the invention is not limited to the warehouse in which the goods are transported. It can also be used in indoor facilities (for example, factories and hospitals where GPS is not available).
Further, the present invention is an invention for preventing an automatic guided vehicle from stopping when a camera cannot properly recognize a surrounding object, and exemplifies an environment in which ambient light is incident as such a scene. explained. However, the scene in which the surrounding objects cannot be properly recognized is not limited to the environment in which ambient light is incident. In some cases, such as when people and forklifts coexist in the same environment, the arrangement of surrounding articles may change with time, and the present invention is also useful in such an environment.

Further, the work using the automatic guided vehicle according to the present invention is not limited to the warehousing / delivery work, and can be applied to various works in which the automatic guided vehicle 10 needs to carry the load.

Further, in the above-described embodiment, the configuration having the image sensor 33 is exemplified, but the number of the image sensors 33 is not particularly limited, and the configuration may have a single image sensor 33, or a plurality of image sensors 33 may be used. It may be configured to have. In the case of a configuration having a plurality of image sensors 33, a support column 73, a color cone 74, a color tape 75, a signboard attached to the ceiling (not shown), etc., based on images captured in a plurality of directions captured by the plurality of image sensors 33, etc. By recognizing the feature point information of the above, recognizing the current position, and performing running control, it is possible to improve the recognition accuracy of the current position and the running control accuracy.

1 RM server 2 WMS server 3 Management terminal 4 Handy terminal 5 Wireless LAN base unit 6 Basket car 7 Landmark image projection device 10 Automated guided vehicle 11 Robot control unit 12 Display unit 16 Base 21 Drive control device 22 Drive device 23 Wheel 31 Front Sensor 32 Side sensor 33 Image sensor 71 Floor line 72 Passage line 73 Prop 74 Color cone 75 Color tape 76 Floor guidance line 77 Wall guidance line 78 Ceiling guidance line 79 Two-dimensional code 81 Virtual guidance line 82 Virtual control sign

Claims (12)

An image sensor that captures an image of an object in the direction of travel,
A drive unit that independently controls the drive of multiple wheels,
A robot control unit that sends control commands to the drive unit for autonomous driving along the travel path based on the environmental map, and a robot control unit.
With a wireless communication unit,
The robot control unit has a function to constantly update the environment map and route based on the image information from the image sensor.
A function to register an image of a specific shape or pattern arranged along the travel path as a landmark image in association with coordinate information on an environmental map, and
The first current position estimation function that recognizes feature points in the image information from the image sensor and estimates the current position in comparison with the environmental map,
When the image information from the image sensor includes a landmark image, a second current position estimation function that estimates the current position based on the coordinate information of the landmark image, and
Equipped with
An automatic guided vehicle characterized by including a projected image as the landmark image. The drive unit has a function of transmitting rotation information of the plurality of wheels as odometry information to the robot control unit.
The automatic guided vehicle according to claim 1, wherein the robot control unit includes a third current position estimation function that estimates the current position based on the odometry information and the current position information stored immediately before. The robot control unit has a function to continuously generate a composite image in which a virtual image is added to the image information from the image sensor.
The automatic guided vehicle according to claim 1 or 2, further comprising a function of performing traveling control based on a virtual image included in the composite image. The projected image is an image of a line, a pattern, an artificial code, a character string, a logo, or a character projected on a floor surface, a wall surface, and / or a ceiling.
The automatic guided vehicle according to any one of claims 1 to 3, wherein the robot control unit has a function of controlling traveling based on the projected image. The automatic guided vehicle according to any one of claims 1 to 4, further comprising a line follow function for traveling along a line projected along the traveling path. The automatic guided vehicle according to any one of claims 1 to 5, wherein the landmark image includes an image of an artificial code including a two-dimensional code. The automatic guided vehicle according to any one of claims 1 to 6 and the automatic guided vehicle.
A landmark image projection device that projects an image of a line, pattern, artificial code, character string, logo, or character along the track.
An automatic guided vehicle system equipped with. The landmark image projection device has a function of projecting an image of a line, a pattern, an artificial code, a character string, a logo, or a character on a floor surface, a wall surface, and / or a ceiling along the traveling path. The unmanned transport vehicle system according to claim 7, wherein the system is characterized by the above. A claim characterized in that the landmark image projection device has a function of projecting an image of a line, a pattern, an artificial code, a character string, a logo, or a character on a passage portion that is a boundary between the travel path and a work section. Item 7. The automatic guided vehicle system according to Item 7. The automatic guided vehicle system according to any one of claims 7 to 9, wherein the landmark image projection device includes a server for transmitting a projection command for projecting a specific image. The projection command is a projection command for projecting a first image for causing the automatic guided vehicle to perform the first travel control and a second image for causing the automatic guided vehicle to perform the second travel control. The automatic guided vehicle system according to claim 10, wherein the automatic guided vehicle system is included. A claim characterized in that the server transmits a projection command for projecting the first image in a first time zone and a projection command for projecting the second image in a second time zone. 11. The unmanned carrier system according to 11.

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