JP7207046B2 - Autonomous mobile device, guidance system, and method of moving autonomous mobile device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an autonomous mobile device, a guidance system, and a method of moving an autonomous mobile device.

2. Description of the Related Art Conventionally, automating transportation work in a warehouse by using an automated guided vehicle (AGV), which is an autonomous mobile device, has been widely studied in the world. Specifically, there is already known a configuration in which an automatic guided vehicle is provided with a connection mechanism, an object to be conveyed (cart cart) is connected to the automatic guided vehicle, and the object is conveyed in a warehouse.

In the automation of transportation work, on a fixed route such as aisles in a warehouse, the guide tape installed on the floor is recognized by a camera, etc., so that the automatic guided vehicle can move while recognizing its own position. methods are generally known. On the other hand, when trying to separate the object to be transported (cart) from the guide tape in a storage area such as a truck berth, a method for recognizing the position of the vehicle that does not depend on the guide tape is required. .

In Patent Document 1, the shape of the surrounding environment is measured or image recognition by a camera is used to discriminate a plurality of markers stored in advance from the surrounding environment, and the position of the vehicle is estimated from the positions of the discriminated markers. A method for doing so is disclosed.

Patent Literature 2 discloses a technique of providing reflectors on both sides of a garage entrance, measuring the coordinate position and attitude angle of the vehicle, and guiding the vehicle into the garage by correcting the track.

However, according to the techniques disclosed in Patent Document 1 and Patent Document 2, there is room for improvement in applying the motion to move to a desired stop position while determining the vehicle's own position.

For example, when there are a plurality of stop positions in a stop area (storage area), when applying the technology disclosed in Patent Document 1, each of the plurality of predetermined positions corresponding to each of the plurality of stop positions has a unique shape. It is necessary to prepare a plurality of markers, and furthermore, it is necessary to distinguish between the plurality of markers. For this reason, according to the technology disclosed in Patent Document 1, pattern matching processing for distinguishing between a plurality of markers is required, which is time-consuming when changing the position and range of the stop area, which is costly. , there is a problem.

In addition, when applying the technology disclosed in Patent Document 2, since the reflector cannot be seen after entering the stop area, it is difficult to determine the own position until the vehicle reaches the desired stop position in the stop area. is not suitable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an autonomous mobile device that moves to a desired position while determining its own position without using many kinds of markers or pattern matching processing. do.

In order to solve the above-described problems and achieve the object, the present invention provides an autonomous mobile device that autonomously travels toward a target position. a sensor for measuring the positions of a plurality of guide members provided along a path; a position estimation means for estimating the position of the autonomous mobile device based on the positions of the plurality of guide members measured using the sensors; wherein at least two guide members among the plurality of guide members are provided at positions that can be detected by the sensor when the autonomous mobile device is positioned at the target position, and the position The autonomous mobile device travels autonomously to the target position while estimating the position of the autonomous mobile device by the estimating means, the target positions exist in a plurality of predetermined areas, and the position estimating means determines whether the autonomous mobile device is moving. estimating the position of the autonomous mobile device at a distance L in the traveling direction of the autonomous mobile device when heading to the target position from the guide member to the farthest target position in the predetermined area on a plane where the plurality of The guide members are provided at intervals that satisfy the following formula,
D<2·tan(θ/2)·L
D: Interval between the guide members
θ: Viewing angle of the sensor when both sides of the target position are filled with obstacles
It is characterized by

ADVANTAGE OF THE INVENTION According to this invention, the autonomous moving apparatus has the effect that it can move to a desired position, determining a self-position, without using multiple types of markers or pattern matching processing.

FIG. 1 is an explanatory diagram showing a self-propelled robot and a basket carriage in a transport system according to a first embodiment. FIG. 2 is a perspective view showing an example in which an ID panel is arranged on a cart. FIG. 3 is an explanatory diagram showing an example of a distribution warehouse to which the transportation system is supposed to be applied. FIG. 4 is a diagram showing an example of installation of reflectors. FIG. 5 is a block diagram showing an example of the hardware configuration of the controller of the self-propelled robot. FIG. 6 is a block diagram showing a functional configuration example exhibited by the controller of the self-propelled robot. FIG. 7 is a diagram showing a table that stores garage locations. FIG. 8-1 is a diagram showing the operation of entering the garage by traveling backward to the storage area of the self-propelled robot (basket trolley). FIG. 8-2 is a diagram showing the operation of putting the self-propelled robot (basket trolley) into the garage by traveling backward to the storage area. FIG. 8-3 is a diagram showing the operation of entering the garage by traveling backward to the storage area of the self-propelled robot (basket trolley). FIG. 9-1 is a diagram showing a garage entry operation by forward traveling of the self-propelled robot (basket trolley) to the storage area. FIG. 9-2 is a diagram showing a garage entry operation by forward traveling of the self-propelled robot (basket trolley) to the storage area. 10A and 10B are diagrams for explaining positional conditions for seeing two reflectors according to the second embodiment. FIG. FIG. 11 is a diagram showing examples of Dmax and Dmin. FIG. 12 is a diagram showing a modification of the arrangement of reflectors.

Embodiments of an autonomous mobile device, a guidance system, and a method for moving the autonomous mobile device will be described in detail below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is an explanatory diagram showing a self-propelled robot 1 and a cage carriage 2 in a transport system according to the first embodiment. This embodiment is an automated guided vehicle (AGV) that automatically transports the basket trolley 2 to a desired destination by automatically connecting to and towing a towed trolley such as the basket trolley 2 to be connected. ) is applied to an autonomous mobile device, which is an example of a transport system that is an example of a guidance system.

The self-propelled robot 1 is an autonomous mobile device having a function of automatically connecting to a basket cart 2 on which goods are loaded. As a result, the self-propelled robot 1 does not need to have a structure capable of being loaded, and by pulling the cage carriage 2 with a simple moving device, a large number of objects loaded on the cage carriage 2 can be transported. can.

As shown in FIG. 1, the self-propelled robot 1 includes a robot body 100 as a device body, a magnetic sensor 3, a controller 4 as a detection device, a power source (battery) 6, a power motor 7, a motor driver 8, a first range sensor 9, coupling device 10, drive wheel 71, driven wheel 72, and the like. Range sensor 9 recognizes the surrounding environment of self-propelled robot 1 .

In the transport system of the present embodiment, a magnetic tape is installed as a guide tape on the floor of the route on which the self-propelled robot 1 can travel, and the magnetic sensor 3 is used to detect the magnetic tape, thereby allowing the self-propelled robot 1 to travel. It can be recognized that it is located on an appropriate route. The guidance method for installing the tape on the floor is not limited to the configuration using the magnetic tape (magnetic type), but may be the configuration using the optical tape (optical type). When using an optical tape, a reflective sensor, an image sensor, or the like can be used instead of the magnetic sensor 3 .

Further, in the transport system of this embodiment, it is possible to autonomously travel by recognizing its own position by collating the two-dimensional or three-dimensional map with the detection result of the range sensor 9 . The range sensor 9 is a scanning laser distance sensor (laser range finder (LRF)) that irradiates an object with laser light and measures the distance to the object from the reflected light. Henceforth, the range sensor 9 may be described as LRF9.

In addition to the laser range finder (LRF), a stereo camera, a depth camera, etc. can also be used as a sensor for recognizing the self position by matching the detection result with a two-dimensional or three-dimensional map.

In the self-propelled robot 1, the controller 4 controls the driving of the power motor 7 via the motor driver 8 based on the detection results of the magnetic sensor 3 and the range sensor 9, and the power motor 7 rotates the drive wheels 71. As a result, the self-propelled robot 1 runs autonomously.

As shown in FIG. 1, the basket truck 2 includes a bottom plate 22 that holds the basket portion 20, casters 23 arranged at the four corners of the rectangular bottom plate 22, and identification members arranged on the side surfaces of the basket portion 20. and an ID panel 21 .

An ID panel 21 on which a recognition marker is displayed is attached to the basket truck 2 placed at a predetermined place. For the marker, the identification number information (ID information) of the cage cart 2, the destination information such as the transportation position, and the priority information of transportation are coded using retroreflective tape 21b (see FIG. 2) or the like, which is a band-shaped member. ing. The identification number information (ID information) of the cart 2 can be recognized by referring to a table or the like.

The self-propelled robot 1 is equipped with a marker reader. The marker reader comprises a range sensor 9 as ID recognition means and a decoding section. In this embodiment, the controller 4 functions as a decoding section. The controller 4 recognizes the marker code from the detection result of the range sensor 9 . The decoding unit of the controller 4 decodes the code information of the recognized marker to obtain identification number information, transport destination information, and priority information of the cart 2 .

In this embodiment, a retroreflective tape 21b is used as a marker installed on the cart 2. As shown in FIG. The self-propelled robot 1 reads using a range sensor 9 such as a laser range finder (LRF) that obtains the distance to the surrounding environment. The controller 4 calculates the position coordinates of the ID panel 21 from distance information between the ID panel 21 whose position is recognized by the range sensor 9 and the range sensor 9 . Using the calculated positional coordinates of the ID panel 21 , the controller 4 drives and controls the power motor 7 to position the self-propelled robot 1 at a predetermined position in front of the ID panel 21 on the cart 2 .

Next, the ID panel 21 will be described in detail.

Here, FIG. 2 is a perspective view showing an example in which the ID panel 21 is arranged on the cart 2. As shown in FIG. As shown in FIG. 2 , the ID panel 21 is arranged substantially centrally on the front surface of the cage carriage 2 . More specifically, the ID panel 21 is arranged at a position facing the range sensor 9 of the self-propelled robot 1 (see FIG. 1). The ID panel 21 is attachable to and detachable from the cage carriage 2 and is installed at a predetermined position such as the central frame (vertical bar) of the cage carriage 2 by an operator. Since the angle of the ID panel 21 is synonymous with the angle of the cage carriage 2 , it is installed so as to be parallel to the front portion of the cage carriage 2 .

In order for the self-propelled robot 1 to connect the cage carriage 2, the self-propelled robot 1 needs to detect the distance and angle between the cage carriage 2 and the self-propelled robot 1 and travel toward the cage carriage 2. . However, when the range sensor 9 recognizes the shape of the cage truck 2, the shape to be recognized changes depending on the loading condition of the cage truck 2, so it is difficult to accurately detect the distance and angle to the cage truck 2. . Therefore, in the present embodiment, the ID panel 21 is attached to the cart 2 and the range sensor 9 mounted on the self-propelled robot 1 detects the ID panel 21 .

Here, the ID panel 21, which is an identification member, will be technically described. The ID panel 21 is an identification member for detecting and identifying a detection target by a detection device using electromagnetic waves such as a laser range finder (LRF). In order to perform detection using electromagnetic waves or the like, the detection surface (for example, the surface of the ID panel 21) where the electromagnetic waves are detected is geometrically arranged in at least three directions in the first direction (horizontal direction in the ID panel 21 shown in FIG. 2). It is divided into regions, and in a plurality of divided regions, at least adjacent regions are set to have different reflectances with respect to electromagnetic waves and the like. A detector such as a laser range finder (LRF) also scans in this first direction. (In the case of a laser range finder (LRF), the laser scans in this first direction.)

Then, the detection device detects and identifies a detection target by detecting a specific pattern (signal) using a difference in intensity of a reflected signal when an electromagnetic wave or the like is irradiated.

The transport system of the present embodiment using the self-propelled robot 1 automates the work of transporting a transport object with casters such as a basket trolley 2 in a distribution warehouse or the like. The transportation operation by the self-propelled robot 1 is divided into the following three operations (1) to (3).
(1) Searching and connecting objects to be transported in the temporary storage area (2) Traveling in the travel area (3) Searching for storage locations and unloading in the storage area

FIG. 3 is an explanatory diagram showing an example of a distribution warehouse 1000 to which the transportation system is assumed. FIG. 3 shows a plan view of the floor surface of the distribution warehouse 1000 viewed from the ceiling side. The XY plane shown in FIG. 3 is a plane parallel to the floor surface, and the Z axis indicates the height direction. In the physical distribution warehouse 1000 shown in FIG. 3, the temporary storage area A1 of (1) above is assumed to be a place where, for example, packages after picking (collection work in the warehouse) or unloaded packages are arranged. The storage area A2 in (3) above is assumed to be an area in front of the truck parking position for each direction of the truck berth, or an area in front of the elevator when transferring to another floor by an elevator or the like. Also, the traveling area A3 in (2) above is assumed to be a place where the arrow in FIG. 3 indicates a round-trip route between the temporary storage area A1 and the storage area A2.

The self-propelled robot 1 moves on the main line by a guidance method based on line recognition in which a sensor recognizes the line of the magnetic tape installed on the floor. Also, the area is determined by detecting the area mark 52 on the side of the line. Further, the ID panel 21 includes information on the storage area A2 to be the transfer destination and information on the order of priority.

As shown in FIG. 3, a magnetic tape for guiding the self-propelled robot 1 is provided in a line in the travel area A3, and a travel line 51 along which the self-propelled robot 1 travels is provided. Also, area marks 52 are arranged near the travel line 51 at the start and end positions of the temporary placement area A1 and the storage area A2 in the travel area A3 to recognize in which area the self-propelled robot 1 is located. It is possible.

In the program executed by the self-propelled robot 1, which will be described later, an action can be specified for each area. The self-propelled robot 1 performs the connection operation of the basket carriage 2 in the temporary storage area A1, and the operation of putting the basket carriage 2 into the garage in the storage area A2. After the transportation of the basket trolley 2 to the storage area A2 is completed, the self-propelled robot 1 automatically moves to the temporary storage area A1 where the basket trolley 2 is placed in order to carry the next basket trolley 2 without the help of an operator. Move by running.

In this embodiment, the travel line 51 made of magnetic tape for guiding the self-propelled robot 1 is provided in the travel area A3, but the present invention is not limited to this. For example, the travel line 51 is not essential in the travel area A3, and area marks may be installed at predetermined intervals. In this case, the self-propelled robot 1 determines its own position from the number of rotations of the drive wheels 71 and the driven wheels 72 and the like, and travels between the area marks.

In the present embodiment, the temporary placement area A1 and the storage area A2 are arranged immediately beside the travel line 51. As shown in FIG. The self-propelled robot 1 searches the areas of the temporary placement area A1 and the storage area A2 while traveling along the travel line 51. - 特許庁When the basket trolley 2 to be transported is found in the temporary placement area A1, the connection operation to the basket trolley 2 from the running line 51 is performed. Also, in the storage area A2, a vacant address is searched from the running line 51, and the car carriage 2 is moved into the garage.

In addition, in the distribution warehouse 1000 shown in FIG. 3, a retroreflective tape 53 (a guide member), which is a reflective material, is provided on the opposite side of the storage area A2 across the travel line 51 and away from the storage area A2. are installed multiple times. A plurality of retroreflective tapes 53 are installed in a direction (X-axis direction, predetermined direction) along the traveling line 51, and the range sensor 9 of the self-propelled robot 1 can be detected by using the walls and shelves of the distribution warehouse 1000. is installed in a position where it can be detected. The self-propelled robot 1 estimates its own position based on the installation information of the plurality of retroreflective tapes 53 .

As shown in FIG. 3, the storage area A2 does not have a magnetic tape running line for guiding the self-propelled robot 1. As shown in FIG. That is, when trying to separate the cage cart 2 from the self-propelled robot 1 at a predetermined position off the travel line 51, such as in the vicinity of the storage area A2, a method for recognizing the position of the own vehicle that does not rely on the travel line 51 is required. becomes.

Therefore, in the present embodiment, the self-propelled robot 1 scans the entire storage area A2 with the range sensor 9, determines a stop position from among a plurality of stop positions, and moves to the determined stop position. Based on the installation information of the corresponding retroreflective tape 53, the vehicle stops at the determined stop position while judging its own position.

Here, the condition of the interval when installing a plurality of retroreflective tapes 53 will be described.

Here, FIG. 4 is a diagram showing an installation example of the reflector. As shown in FIG. 4, a plurality of retroreflectors, which are reflective materials, are placed on the opposite side of the travel line 51 from the storage area A2 where the cart 2 is parked and at a position where the range sensor 9 of the self-propelled robot 1 can detect. A reflective tape 53 is installed. The self-propelled robot 1 estimates its own position based on the installation information of the retroreflective tape 53, for example, as follows. The self-propelled robot 1 stores the installation intervals of the plurality of retroreflective tapes 53 in advance, and the range sensor 9 detects at least two retroreflective tapes 53 from the position of the vehicle. The self-propelled robot 1 estimates its own position using triangulation from the distance and angle to two retroreflective tapes 53 whose distance is known.

FIG. 4 shows four garages arranged in two rows and two columns in the storage area A2. Three retroreflective tapes 53 are installed so that the range sensor 9 can detect at least two retroreflective tapes 53 when the vehicle is parked in either row of garages. These three retroreflective tapes 53 do not need to have unique shapes and sizes, and may have shapes and sizes that allow the retroreflective tape 53 to be recognized as the retroreflective tape 53 . Here, the three retroreflective tapes 53 have the same shape and size. As described above, since there is no restriction on the shape and size of the retroreflective tape 53, the ease of installation is improved and the installation can be done at low cost. In addition, by using the retroreflective tapes 53 having the same shape and size, the ease of installation is enhanced and the installation cost can be reduced.

As shown in FIG. 4, by setting a plurality of retroreflective tapes 53 on opposite sides of the storage area A2 and the traveling line 51 and at positions where the range sensor 9 of the self-propelled robot 1 can detect, You can get the effect like For example, if you want to park in a vacant garage in storage area A2, which is surrounded by obstacles such as shelves and has a plurality of partitioned garages, the direction opposite to the direction of travel after entering storage area A2 is desired. Since the retroreflective tape 53 can be recognized using the field of view of , the vehicle position can be estimated.

When setting the storage area A2 on the opposite side of the article shelf, it is preferable to attach a plurality of retroreflective tapes 53 using the side surface of the shelf or the frame. When the car trolley 2 loaded with cargo is towed and the robot 1 is put into the garage by traveling backward, it becomes difficult to secure the rearward visibility of the self-propelled robot 1. Since the position of the vehicle can be known by the fact that the vehicle is moving backward, it is most suitable for such parking in reverse driving.

Next, the controller 4 of the self-propelled robot 1 will be explained.

Here, FIG. 5 is a block diagram showing an example of the hardware configuration of the controller 4 of the self-propelled robot 1. As shown in FIG. As shown in FIG. 5, the controller 4 includes a control device 11 such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and a main storage device 12 such as a ROM (Read Only Memory) or a RAM (Random Access Memory). , an auxiliary storage device 13 such as an SSD (Solid State Drive), a display device 14 such as a display, an input device 15 such as a keyboard, and a communication device 16 such as a wireless communication interface. It has a hardware configuration using a computer.

The control device 11 executes various programs stored in the main storage device 12 and the auxiliary storage device 13 to control the overall operation of the controller 4 (self-propelled robot 1) and realize various functional units described later. .

The program executed by the controller 4 of the self-propelled robot 1 is a file in an installable format or an executable format, and can be stored on a computer such as a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile Disk). It may be configured to be recorded on a readable recording medium and provided.

Furthermore, the program to be executed by the controller 4 of the self-propelled robot 1 may be stored on a computer connected to a network such as the Internet, and provided by being downloaded via the network. Alternatively, the program executed by the controller 4 of the self-propelled robot 1 may be provided or distributed via a network such as the Internet.

Next, the functions that the controller 4 of the self-propelled robot 1 exhibits when the control device 11 of the controller 4 of the self-propelled robot 1 executes the programs stored in the main storage device 12 and the auxiliary storage device 13 will be described. Here, description of conventionally known functions will be omitted, and the characteristic functions exhibited by the controller 4 of the self-propelled robot 1 of the present embodiment will be described in detail.

Part or all of the functions exhibited by the controller 4 of the self-propelled robot 1 may be configured using a dedicated processing circuit such as an IC (Integrated Circuit).

FIG. 6 is a block diagram showing a functional configuration example exhibited by the controller 4 of the self-propelled robot 1. As shown in FIG. As shown in FIG. 6, the controller 4 of the self-propelled robot 1 has position estimation means 111 .

The position estimation means 111 estimates the position of the self-propelled robot 1 from the positions of the plurality of retroreflective tapes 53 measured using the range sensor 9 when entering the storage area A2.

Next, the movement of the self-propelled robot 1 (basket trolley 2) into the storage area A2 will be described in detail.

Here, FIG. 7 is a diagram showing a table T for storing garage positions. The controller 4 of the self-propelled robot 1 stores in advance the position coordinates of the garage in the storage area A2 as a table T, as shown in FIG. 7(b). As shown in FIG. 7A, four garages are provided in the storage area A2. Garage no. 1 position coordinates (X1, Y1), garage No. 2 is (X2, Y1), garage No. 3 is (X1, Y2), garage No. 4 is assumed to be (X2, Y2). In the state shown in FIG. 7(a), garage No. Only 2 are vacant. Also in the table shown in FIG. 7(b), garage No. It is remembered that only 2 is free.

FIGS. 8-1 to 8-3 are diagrams showing the operation of putting the self-propelled robot 1 (basket trolley 2) into the storage area A2 by moving backward.

8-1 to 8-3, the self-propelled robot 1 moves backward to the storage area A2 while towing the basket trolley 2, and completes parking. It is a series of operations to return to the traveling operation on the traveling line 51 again after the car carriage 2 is separated.

First, as shown in FIG. 8-1(a), the controller 4 (position estimation means 111) of the self-propelled robot 1 controls the self-propelled robot 1 to travel along the travel line 51 until it finds the area mark 52. .

As shown in FIG. 8-1(b), the controller 4 (position estimation means 111) of the self-propelled robot 1 temporarily stops the self-propelled robot 1 when the area mark 52 is detected.

Next, as shown in FIG. 8-1(c), the controller 4 (position estimating means 111) of the self-propelled robot 1 scans the entire storage area A2 with the range sensor 9 while traveling again. Use T to search for an empty garage in storage area A2.

Here, in FIG. 8-1(c), the range sensor 9 used for searching for an empty garage is preferably of a type with a horizontal field of view of 270 degrees or 360 degrees. When using a type with a field of view of 270 degrees, the self-propelled robot 1 is installed in a direction that allows measurement of the storage area A2 while traveling on the travel line 51 . If a plurality of vacant garages are found, a method such as prioritizing the garages in the storage area A2 for selection may be adopted.

As shown in FIG. 8-1(d), when the controller 4 (position estimating means 111) of the self-propelled robot 1 detects an empty garage in the storage area A2, the self-propelled robot 1 is moved to the empty garage position (here, Stop in front of Garage No. 2).

In FIG. 8-1(d), the controller 4 (position estimating means 111) of the self-propelled robot 1 causes the self-propelled robot 1 to travel to the end of the storage area A2, and checks the availability of all garages in the storage area A2. After searching, the vehicle may be stopped at the coordinate position of the desired garage.

Next, as shown in FIG. 8-2(e), the controller 4 (position estimation means 111) of the self-propelled robot 1 turns the self-propelled robot 1 so that the basket cart 2 faces the garage.

As shown in FIG. 8-2(f), the controller 4 (position estimating means 111) of the self-propelled robot 1, after turning, uses the retroreflective tape 53 to estimate its self-position and moves the garage number. A direction parallel to the Y-axis is defined as a traveling direction toward the position coordinates (X2, Y1) of 2, and the self-propelled robot 1 is caused to travel along this traveling direction. This position coordinate (X2, Y1) becomes the target position of the self-propelled robot 1 .

As shown in FIG. 8-2(g), the controller 4 (position estimating means 111) of the self-propelled robot 1 is the garage number. 2 position coordinates (X2, Y1), the basket cart 2 is separated from the self-propelled robot 1 .

Next, as shown in FIG. 8-2(h), the controller 4 (position estimating means 111) of the self-propelled robot 1 uses the retroreflective tape 53 to estimate the self-position after the car carriage 2 has been separated. While doing so, the self-propelled robot 1 is made to travel until a travel line 51 is found.

As shown in FIG. 8-3(i), the controller 4 (position estimation means 111) of the self-propelled robot 1 turns the self-propelled robot 1 when the travel line 51 is found.

Then, as shown in FIG. 8-3(j), the controller 4 (position estimating means 111) of the self-propelled robot 1 returns to the recognition travel motion of the travel line 51 after turning.

By the above operation, the controller 4 (position estimating means 111) of the self-propelled robot 1 can control the travel of the self-propelled robot 1 that has estimated its own position in the storage area A2 off the travel line 51. FIG. In other words, the self-propelled robot 1 can travel while estimating its own position in the storage area A2 off the travel line 51 .

As described above, according to the present embodiment, when the self-propelled robot 1 is put into the storage area A2 off the travel line 51, the pattern matching process is not performed without using many types of markers. It is possible to enter the storage area A2 while estimating the vehicle position and stop at the target position within the storage area A2 without increasing the processing load.

In this embodiment, the operation of entering the garage by backward traveling has been described, but the present invention is not limited to this. The self-propelled robot 1 uses the range sensor 9 to determine the position of the self-propelled robot 1 even when entering the garage by traveling forward after turning so that the front of the self-propelled robot 1 faces an empty garage in the storage area A2. It can be applied as an estimation method. The operation for entering the garage by moving forward will be described below.

FIGS. 9-1 and 9-2 are diagrams showing the garage operation by forward traveling of the self-propelled robot 1 (basket cart 2) to the storage area A2. In the example shown in FIG. 9, it is assumed that the storage area A2 is sandwiched between two travel lines 51. As shown in FIG. In addition, a plurality of retroreflective tapes 53, which are reflective materials, are installed on the side where the self-propelled robot 1 leaves when traveling forward.

9-1 and 9-2, the self-propelled robot 1 moves forward while towing the basket trolley 2 to enter the storage area A2. It is a series of operations to return to the traveling operation on the traveling line 51 again after the car carriage 2 is separated. The operation of entering the storage area A2 is omitted because it is the same as the backward travel in FIGS. 8-1(a) and (b).

As shown in FIG. 9-1(a), the controller 4 (position estimation means 111) of the self-propelled robot 1 causes the range sensor 9 to scan the entire storage area A2 while causing the self-propelled robot 1 to travel again. , search for an empty garage in the storage area A2 using the table.

As shown in FIG. 9-1(b), when the controller 4 (position estimating means 111) of the self-propelled robot 1 detects an empty garage in the storage area A2, the self-propelled robot 1 is moved to the empty garage position (here, Stop in front of Garage No. 2).

Next, as shown in FIG. 9-1(c), the controller 4 (position estimation means 111) of the self-propelled robot 1 turns the self-propelled robot 1 so that the basket cart 2 faces the garage.

As shown in FIG. 9-1(d), the controller 4 (position estimation means 111) of the self-propelled robot 1, after turning, uses the retroreflective tape 53 to estimate its self-position and moves the garage number. The self-propelled robot 1 is caused to run toward the position coordinates of 2.

As shown in FIG. 9-2(e), the controller 4 (position estimating means 111) of the self-propelled robot 1 is the garage number. 2, the cage carriage 2 is separated from the self-propelled robot 1. - 特許庁

Next, as shown in FIG. 9-2(f), the controller 4 (position estimating means 111) of the self-propelled robot 1 uses the retroreflective tape 53 to estimate the self-position after the car carriage 2 has been separated. While doing so, the self-running robot 1 is moved forward until it finds a running line 51.例文帳に追加

As shown in FIG. 9-2(g), the controller 4 (position estimation means 111) of the self-propelled robot 1 turns the self-propelled robot 1 when the travel line 51 is found.

Then, as shown in FIG. 9-2(h), the controller 4 (position estimating means 111) of the self-propelled robot 1 returns to the recognition travel motion of the travel line 51 after turning.

(Second embodiment)
Next, a second embodiment will be described.

The conveying system of the second embodiment differs from that of the first embodiment in that the arrangement of the retroreflective tapes 53 is defined so that two retroreflective tapes 53 can be reliably found. Hereinafter, in the description of the second embodiment, the description of the same portions as those of the first embodiment will be omitted, and the portions different from those of the first embodiment will be described.

As shown in FIG. 4 of the first embodiment, in order for the controller 4 (position estimating means 111) of the self-propelled robot 1 to identify the position and orientation of the own vehicle, at least two retroreflective tapes 53 are used. Range sensor 9 needs to detect. However, for example, when a car is parked on both sides of an empty garage in the storage area A2 and the car enters between them, the field of view (viewing angle, detection range) in which the range sensor 9 can detect the retroreflective tape 53 becomes narrower. Therefore, in the present embodiment, the arrangement of the retroreflective tapes 53 is defined so that two retroreflective tapes 53 can be reliably detected.

Here, FIG. 10 is a diagram for explaining positional conditions for detecting two reflectors according to the second embodiment. As shown in FIG. 10, the distance between the retroreflective tapes 53 is "D". Let θ be the viewing angle when both sides of the vacant garage line (parking position) are filled with obstacles.

When the self-propelled robot 1 tows the car carriage 2 and backs up into the garage, the range sensor 9 on the self-propelled robot 1 at the farthest position from the travel line 51 and the surface on which the retroreflective tape 53 is installed. Let L be the distance from When the self-propelled robot 1 comes to the position of this distance L, it is necessary to detect two or more retroreflective tapes 53, so the interval D between the retroreflective tapes 53 is defined by the following formula (1).
D<Dmax
Dmax=2·tan(θ/2)·L (1)
D: Interval
θ: Viewing angle when both sides of an empty garage line are filled with obstacles
L: Distance from the reflector to the farthest parking position

Here, it is desirable that the distance D between the retroreflective tapes 53 is as large as possible as long as it does not exceed Dmax. The reason for this is that, in triangulation, if the distance between the retroreflective tapes 53 is too small, the accuracy of position estimation will be degraded. This is because when the space between the retroreflective tapes 53=the base line is the base and the position of the vehicle is the vertex, the change in the angle of contact with the base line with respect to the change in height is very small.

Here, FIG. 11 is a diagram showing an example of Dmax and Dmin. As shown in FIG. 11, as an example, consider a case where the storage area A2 has three sections in the depth direction of the garage, and one section has a width of 0.8 [m] and a depth of 1 [m]. Assuming that the self-propelled robot 1 enters the garage by itself, the self-propelled robot 1 enters the garage in the depth direction for about 2.5 sections of the garage. Let L=4 [m] be the distance from the surface on which the reflective tape 53 is installed. In this case, when Dmax is obtained, Dmax=1.28 [m].

From the viewpoint of using the range sensor 9 to detect the retroreflective tapes 53, it is desirable that the minimum distance between the two retroreflective tapes 53 is as follows, as shown in FIG. When two retroreflective tapes 53 are adjacent to each other, in order to distinguish between them, at least an interval is required so that they do not appear to overlap when detected by the range sensor 9 . That is, Dmin is defined by the following formula (2) as the interval for at least one beam diameter to be included between two retroreflective tapes 53 . Here, let φ be the beam diameter at the exit end of the laser light source, α be the divergence angle, and L be the distance between the range sensor 9 on the self-propelled robot 1 and the surface on which the retroreflective tape 53 is installed.
Dmin<D
Dmin=φ+αL (2)

As shown in FIG. 11, as an example, when L = 4 [m], the beam diameter φ at the output end = 0.02 [m], and the divergence angle α = 4.3 [mrad], the distance L = 4 [m ], Dmin=0.0372 [m].

As described above, according to the present embodiment, the self-propelled robot 1 can reliably find two or more retroreflective tapes 53 from the vehicle position.

Here, FIG. 12 is a diagram showing a modification of the reflector arrangement. When three or more retroreflective tapes 53 are provided on the same line, if they are arranged at regular intervals (periods), even positions separated by periodic intervals may be recognized as the own vehicle position, causing erroneous recognition. On the other hand, misrecognition can be reduced by setting the intervals of the retroreflective tapes 53 at irregular intervals. In the example shown in FIG. 12, the distance between the retroreflective tapes 53 is a≠b.

Further, as a method of reducing erroneous recognition of self-position estimation, the retroreflective tape 53 may be arranged at different positions in the direction of entering the garage (the direction intersecting the running line 51). Rather than arranging the retroreflective tapes 53 on the same line, by creating a pattern that changes in the depth direction when detecting the retroreflective tape 53, a difference in the detection pattern is likely to occur, and the vehicle position of the self-propelled robot 1 is easily detected. becomes easier to decide in one place. In the example shown in FIG. 12, the interval between the retroreflective tapes 53 is c≠d≠e. By not installing a plurality of retroreflective tapes 53 on the same line in this way, misrecognition can be further reduced.

In each embodiment, an automated guided vehicle (AGV) that automatically transports the basket trolley 2 to a desired destination by automatically connecting to and towing a towed trolley such as the basket trolley 2 that is a connection target. Although an example in which the self-propelled robot 1 is applied to an autonomous mobile device has been described, it is needless to say that it is not limited to this and can be applied to various autonomous mobile devices.

REFERENCE SIGNS LIST 1 autonomous mobile device 9 range sensor 53 a plurality of reflectors 111 position estimation means

JP 2017-204043 A Japanese Patent No. 2676971

Claims (6)

In an autonomous mobile device that autonomously travels toward a target position,
a sensor that measures the positions of a plurality of guide members provided along a predetermined direction that intersects the traveling direction of the autonomous mobile device when heading toward the target position;
position estimating means for estimating the position of the autonomous mobile device based on the positions of the plurality of guide members measured using the sensor;
with
At least two guide members among the plurality of guide members are provided at positions that can be detected by the sensor when the autonomous mobile device is positioned at the target position,
While estimating the position of the autonomous mobile device by the position estimation means, the autonomous mobile device travels autonomously to the target position;
A plurality of the target positions exist within a predetermined area,
In the plane on which the autonomous mobile device moves, the position estimating means measures the distance L in the traveling direction of the autonomous mobile device when heading from the guide member to the farthest target position in the predetermined area. Estimate the position of the autonomous mobile device,
The plurality of guide members are provided at intervals satisfying the following formula,
D<2·tan(θ/2)·L
D: Interval between the guide members
θ: Viewing angle of the sensor when both sides of the target position are filled with obstacles
An autonomous mobile device characterized by: A second sensor that detects a travel line indicating the route along which the autonomous mobile device travels or an area mark that allows recognition of the area in which the autonomous mobile device is located,
When the autonomous mobile device returns to the travel line or the area mark, the position estimation means estimates the self-position using the guide member until the second sensor finds the travel line or the area mark. run an autonomous mobile device,
The autonomous mobile device according to claim 1, characterized in that: when the plurality of guide members is three or more, each guide member is provided at non-equidistant intervals in the predetermined direction;
The autonomous mobile device according to claim 1 or 2, characterized in that: The plurality of guide members are provided at different positions in the traveling direction of the autonomous mobile device when heading toward the target position.
The autonomous mobile device according to any one of claims 1 to 3, characterized in that: An autonomous mobile device according to any one of claims 1 to 4,
a plurality of guide members provided along a predetermined direction that intersects the traveling direction of the autonomous mobile device when the autonomous mobile device moves toward a target position;
with
guiding the autonomous mobile device to the target position;
A guidance system characterized by: A moving method for an autonomous mobile device that autonomously travels toward a target position,
a measuring step of using a sensor to measure the positions of a plurality of guide members provided along a predetermined direction intersecting with the traveling direction of the autonomous mobile device when heading toward the target position;
a position estimation step of estimating the position of the autonomous mobile device based on the positions of the plurality of guide members measured in the measurement step;
including
At least two guide members among the plurality of guide members are provided at positions that can be detected by the sensor when the autonomous mobile device is positioned at the target position,
while estimating the position of the autonomous mobile device by the position estimation step, autonomously traveling to the target position;
A plurality of the target positions exist within a predetermined area,
In the position estimating step, in a plane in which the autonomous mobile device moves, at a distance L in the traveling direction of the autonomous mobile device when heading to the target position from the guide member to the farthest target position in the predetermined area Estimate the position of the autonomous mobile device,
The plurality of guide members are provided at intervals satisfying the following formula,
D<2·tan(θ/2)·L
D: Interval between the guide members
θ: Viewing angle of the sensor when both sides of the target position are filled with obstacles
A moving method for an autonomous mobile device, characterized by:

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