JP7136426B2 - Management device and mobile system - Google Patents

Description

The present disclosure relates to mobiles and mobile systems.

Research and development of mobile objects such as automated guided vehicles and mobile robots are underway. For example, JP-A-2009-223634, JP-A-2009-205652, and JP-A-2005-242489 disclose a system for controlling the movement of each mobile body so that a plurality of autonomous mobile bodies do not collide with each other. ing.

JP 2009-223634 A JP 2009-205652 A JP 2005-242489 A

An embodiment of the present disclosure provides a technology for smoother operation of a plurality of mobile bodies capable of autonomous movement.

A management device in an exemplary embodiment of the present disclosure manages operation of a plurality of mobile bodies capable of autonomous movement. The management device includes a first communication circuit that communicates with each of the plurality of mobile bodies, determines an operation route of each of the plurality of mobile objects, and transmits a signal indicating the operation route through the first communication circuit. to each of the plurality of moving bodies. Each of the plurality of mobile bodies includes a second communication circuit that communicates with the first communication circuit, at least one sensor that detects obstacles, and the mobile body according to the traveling route determined by the first control circuit. When an obstacle is detected by the sensor, the second control circuit causes the moving body to avoid the obstacle, and transmits a signal indicating the presence of the obstacle through the second communication circuit and a second control circuit for transmitting. The first control circuit causes one of the plurality of moving bodies to pass through a route on which the obstacle exists when the signal indicating the presence of the obstacle is transmitted from one of the plurality of moving bodies. Change the route of the planned vehicle.

The above generic aspects may be implemented by systems, methods, integrated circuits, computer programs, or recording media. Alternatively, it may be implemented by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

According to an embodiment of the present disclosure, when a moving body performs an action to avoid an obstacle, the path of another moving body is changed to a path that does not collide with the obstacle. As a result, the operation of the mobile system can be made smoother.

FIG. 1 is a diagram schematically showing the configuration of mobile system 100 in an exemplary embodiment of the present disclosure. FIG. 2A shows an example in which there are no obstacles on the traveling route of the moving body 10A. FIG. 2B shows an example of an avoidance operation when an obstacle 70 exists between the marker M1 and the marker M2 on the traveling route of the moving body 10A. FIG. 2C is a diagram illustrating an example of a changed route. FIG. 2D is a diagram showing another example of a changed route. FIG. 3 is a diagram showing an example of data indicating the operation route of each mobile body 10 managed by the management device 50. As shown in FIG. FIG. 4 is a flow chart showing an example of the operation of the first control circuit 51 in the management device 50. As shown in FIG. FIG. 5 is a flow chart showing an example of the operation of the second control circuit 14a in the mobile body 10. As shown in FIG. FIG. 6 is a schematic diagram of a control system that controls travel of each AGV according to the present disclosure. FIG. 7 is a diagram showing an example of a moving space S in which an AGV exists. FIG. 8A shows the AGV and towing truck before they are connected. FIG. 8B is a diagram showing a connected AGV and tow truck. FIG. 9 is an external view of an exemplary AGV according to this embodiment. FIG. 10A is a diagram showing a first hardware configuration example of the AGV. FIG. 10B is a diagram showing a second hardware configuration example of the AGV. FIG. 11A is a diagram showing an AGV that generates a map while moving. FIG. 11B is a diagram showing an AGV that generates a map while moving. FIG. 11C is a diagram showing an AGV generating a map while moving. FIG. 11D is a diagram showing an AGV generating a map while moving. FIG. 11E is a diagram showing an AGV generating a map while moving. FIG. 11F is a diagram schematically showing part of the completed map. FIG. 12 is a diagram showing an example in which a map of one floor is composed of a plurality of partial maps. FIG. 13 is a diagram showing a hardware configuration example of an operation management device. FIG. 14 is a diagram schematically showing an example of an AGV movement route determined by the operation management device.

<Term>
Prior to describing embodiments of the present disclosure, definitions of terms used herein will be provided.

"Automated Guided Vehicle" (AGV) means a trackless vehicle that loads cargo manually or automatically into its main body, travels automatically to a designated location, and unloads manually or automatically. "Automated guided vehicle" includes automated towing vehicles and automated forklifts.

The term "unmanned" means that no person is required to steer the vehicle, and does not exclude that the AGV carries "persons (e.g., those loading and unloading goods)".

An “unmanned tractor” is a trackless vehicle that automatically travels to a designated location by towing a trolley that loads and unloads cargo manually or automatically.

An “unmanned forklift” is a trackless vehicle equipped with a mast that raises and lowers a fork for loading and unloading cargo.

A "trackless vehicle" is a vehicle that has wheels and an electric motor or engine that rotates the wheels.

A “moving object” is a device that moves with a person or load on it, and is equipped with a driving device such as wheels, a bipedal or multipedal walking device, or a propeller that generates a driving force (traction) for movement. The term “mobile” in the present disclosure includes mobile robots, service robots, and drones as well as automated guided vehicles in the narrow sense.

"Automatic driving" includes driving based on commands of a computer operation management system to which the automatic guided vehicle is connected by communication, and autonomous driving by a control device provided in the automatic guided vehicle. Autonomous travel includes not only travel by an automatic guided vehicle toward a destination along a predetermined route, but also travel following a tracking target. Also, the automatic guided vehicle may temporarily travel manually based on instructions from the operator. "Automated driving" generally includes both "guided" driving and "guideless" driving, but in this disclosure means "guideless" driving.

The “guide type” is a system in which derivatives are installed continuously or intermittently, and the guides are used to guide an automatic guided vehicle.

The “guideless type” is a method of guiding without installing a derivative. An automatic guided vehicle according to an embodiment of the present disclosure includes a self-position estimation device and can travel without a guide.

A "self-position estimation device" is a device that estimates a self-position on an environmental map based on sensor data acquired by an external sensor such as a laser range finder.

The "external sensor" is a sensor that senses the state of the exterior of the moving object. External sensors include, for example, laser range finders (also called range sensors), cameras (or image sensors), LIDAR (Light Detection and Ranging), millimeter wave radars, and magnetic sensors.

An "internal sensor" is a sensor that senses the internal state of a moving object. Internal sensors include, for example, rotary encoders (hereinafter sometimes simply referred to as "encoders"), acceleration sensors, and angular acceleration sensors (eg, gyro sensors).

"SLAM" is an abbreviation for Simultaneous Localization and Mapping, which means performing self-localization and environmental map creation at the same time.

<Exemplary embodiment>
An example of a mobile body and a mobile system according to the present disclosure will be described below with reference to the accompanying drawings. Note that more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art. The inventors provide the accompanying drawings and the following description for a full understanding of the present disclosure by those skilled in the art. They are not intended to limit the claimed subject matter. In the following description, identical or similar components are given the same reference numerals.

FIG. 1 is a diagram schematically showing the configuration of mobile system 100 in an exemplary embodiment of the present disclosure. This mobile body system 100 comprises a plurality of mobile bodies 10 capable of moving autonomously, and an operation management device (hereinafter sometimes simply referred to as a "management device") that manages the operation of the plurality of mobile bodies 10. 50. FIG. 1 shows two moving bodies 10 as an example. The mobile system 100 may include three or more mobiles 10 . In this embodiment, the moving body 10 is an automatic guided vehicle (AGV). In the following description, the moving body 10 may be described as "AGV 10". Mobile object 10 may be other types of mobile objects such as, for example, bipedal or multipedal robots, hovercraft, or drones.

The management device 50 includes a first communication circuit 54 that communicates with each of the plurality of mobile units 10 via a network, and a first control circuit 51 that controls the first communication circuit 54 . The first control circuit 51 determines the travel route of each of the plurality of mobile bodies 10 and transmits signals indicating the respective travel routes to the plurality of mobile bodies 10 via the first communication circuit 54 . An operation route may be determined individually for each mobile object 10, or all mobile objects 10 may move according to the same operation route. The travel routes of at least two mobile bodies 10 among the plurality of mobile bodies 10 at least partially overlap.

The "signal indicating the operation route" transmitted from the management device 50 to each mobile object 10 may include, for example, information indicating the positions of a plurality of points on the route from the initial position to the target position. In this specification, such points are sometimes referred to as "markers." Markers can be set at intervals of several tens of centimeters (cm) to several meters (m), for example, along the traveling route of each mobile body 10 .

Each of the plurality of moving bodies 10 moves along the operation route according to instructions from the management device 50 . In a typical example, each moving body 10 has a storage device that stores environmental map data (sometimes simply referred to as an "environmental map"), periodically scans the environment, and outputs sensor data for each scan. and an external sensor. In this case, each moving body 10 moves along the operation route while estimating its own position and pose by matching sensor data and environmental map data.

Each moving body 10 has a function of detecting obstacles on the traveling route and a function of avoiding obstacles. Each mobile body 10 includes a second communication circuit 14e capable of communicating with the first communication circuit 54 via a network, at least one obstacle sensor 19 for detecting an obstacle, and movement and communication of the mobile body 10. and a second control circuit 14a for controlling the The second control circuit 14 a controls a driving device (not shown) to move the moving body 10 according to the route determined by the first control circuit 54 . The second control circuit 14a causes the moving body 10 to avoid the obstacle when the sensor 19 detects the obstacle on the travel route. At this time, the second control circuit 14a transmits a signal indicating the presence of the obstacle to the first communication circuit 54 via the second communication circuit 14e.

The "signal indicating the presence of an obstacle" may include, for example, positional information of the obstacle, information on the trajectory of the moving body that has avoided the obstacle, or information indicating the presence or absence of the obstacle. A signal indicating the presence of an obstacle may include information about the size of the obstacle or the area occupied by the obstacle.

When a signal indicating the presence of an obstacle is transmitted from one of the plurality of moving bodies 10, the first control circuit 51 in the management device 50 selects a route on which the obstacle exists among the plurality of moving bodies 10. Change the route of the moving object 10 that is scheduled to pass.

As an example, an operation will be described in which the signal indicating the travel route includes information indicating the positions of a plurality of points (markers) on the route. When a signal indicating the presence of an obstacle is transmitted from any one of the plurality of moving bodies 10, the first control circuit 54 identifies two adjacent points between which the obstacle is positioned. The first control circuit 54 changes the route of the mobile object 10 scheduled to pass through the route including the two points among the plurality of mobile objects 10 to a route that does not include the two points.

With such an operation, the following moving body 10 can smoothly move along the new route without being affected by obstacles. After one mobile body 10 discovers an obstacle, the other mobile bodies 10 do not need to take actions to avoid the obstacle. Therefore, the operation of the mobile system can be made smoother.

An example of the operation at the time of route change will be described below with reference to FIGS. 2A to 2D. Here, as an example, the "signal indicating the operation route" includes information indicating the positions of a plurality of points (markers) on the route from the initial position to the target position, and the "signal indicating the presence of obstacles" An example in which information indicating the position of an object is included will be described. The "information indicating the position of the obstacle" is not limited to the position (coordinates) of the obstacle itself, but may be information on the position (coordinates) or trajectory of the moving body 10 that has performed the avoidance action.

FIG. 2A shows an example in which there are no obstacles on the traveling route of the moving body 10A. In this case, the moving body 10A moves along a preset operation route (broken line arrow in the figure). More specifically, the moving object 10A sequentially traces a plurality of markers ( _only markers M1 and _M2 are illustrated in FIG. 2A) instructed by the first control circuit 51 of the management device 50, and moves from the initial position to the target position. move up to Movement between markers is linear movement. The moving body 10A may acquire the position information of all markers on the travel route in advance, or may request the position information of the next marker from the management device 50 each time it reaches each marker.

FIG. 2B shows an example of an avoidance operation when an obstacle ₇₀ exists between the marker M1 and the marker _M2 on the traveling route of the mobile object 10A. Obstacles 70 are objects that are not on the environmental map, and may be, for example, packages, people, or other moving objects. The travel route of the moving body 10A is determined in advance assuming that such obstacles do not exist.

When the moving object 10A finds an obstacle 70 on the route using the sensor 19, the moving object 10A performs an operation to avoid the obstacle 70. FIG. For example, the moving body 10A avoids the obstacle 70 by appropriately combining operations such as turning right, turning left, and turning. In the example of FIG. 2B, when the mobile body 10A discovers the obstacle 70, it performs the following operations.
(1) Before the obstacle 70 (for example, several tens of centimeters before), the traveling direction is turned about 90 degrees to the right, and the distance is about the same as the width of the obstacle 70 . The width of obstacle 70 can be measured using, for example, sensor 19 or a laser range finder.
(2) Turn the direction of travel about 90 degrees to the left and move forward over a distance slightly longer than the width of the obstacle 70 .
(3) Turn the direction of travel about 90 degrees to the left and move forward for a distance about the width of the obstacle 70 .
(4) Turn right about 90 degrees and move forward to marker _M2 .

The avoidance operation of the obstacle 70 by the moving object 10A is not limited to this example, and any algorithm can be applied.

Upon discovering the obstacle 70 , the moving body 10</b>A transmits a signal indicating the presence of the obstacle 70 to the management device 50 . The moving body 10A receives, for example, a signal indicating that an obstacle ₇₀ exists between the marker M1 and the marker _M2 , or _an avoidance action of the moving body 10A performed between the marker M1 and the marker _M2 . A signal indicating the trajectory (set of a plurality of coordinates) is transmitted to the management device 50 . If the moving object 10A can measure the coordinates and size of the obstacle 70 using a laser range finder, information on the coordinates and size of the obstacle 70 may be included in the signal.

When the first control circuit 51 of the management device 50 receives the signal indicating the presence of the obstacle 70 from the moving body 10A, there is a following moving body 10 scheduled to pass through the route containing the _two markers M1 and _M2 . determine whether If there is such a mobile object 10, the first control circuit 51 changes the route of the mobile object 10 to a route that does not include the _two markers M1 and _M2 .

FIG. 2C is a diagram illustrating an example of a changed route. In this example, the route of the following moving body 10B is changed to a route that is slightly shifted so as not to collide with the obstacle 70. FIG. The first control circuit 51 of the management device 50 implements this route change by changing the markers M ₁ and M ₂ to markers M ₁ ' and M ₂ '.

FIG. 2D is a diagram showing another example of a changed route. In this example, the route of the following mobile object 10B is significantly changed. The positions of the markers M ₁ ′ and M ₂ ′ after the change are significantly changed from the original positions of the markers M ₁ and M ₂ .

By changing the route as described above, the following moving body 10B can smoothly move to the destination without performing an operation to avoid the obstacle 70. FIG.

FIG. 3 is a diagram showing an example of data indicating the operation route of each mobile body 10 managed by the management device 50. As shown in FIG. Such data can be recorded in a storage device (not shown in FIG. 1) included in the management device 50. FIG. As shown in FIG. 3, the data indicating the travel route of each mobile object 10 can include information on a plurality of points (markers) on the route. Information of each marker may include information of the position of the marker (eg, x-coordinate and y-coordinate) and the orientation of mobile object 10 at that position (eg, angle θ from the x-axis). In FIG. 3, the information of each marker is represented by symbols such as M ₁₁ (x ₁₁ , y ₁₁ , θ ₁₁ ), all of which are recorded as specific numerical values.

FIG. 4 is a flow chart showing an example of the operation of the first control circuit 51 in the management device 50. As shown in FIG. In this example, the first control circuit 51 performs the following operations.
- Step S101: Determine the moving route of each moving body 10 . The movement route is determined according to instructions from the user or administrator, or according to a predetermined program.
Step S102: Start instructing each moving body 10 to move. The timing of starting the instruction to move to each mobile unit 10 is also performed according to an instruction from the user or administrator, or according to a predetermined program.
Step S103: Determine whether or not notification of the presence of an obstacle has been received from any moving body 10 . If this determination is Yes, the process proceeds to step S104. If this determination is No, step S103 is executed again.
Step S104: It is determined whether or not there is a subsequent moving body 10 that is scheduled to pass through a route on which obstacles exist. This determination can be made, for example, based on a comparison between the position of the obstacle and the route of each moving body 10 . If this determination is Yes, the process proceeds to step S105. If this determination is No, the process returns to step S103.
Step S105: Change the route of the following moving object 10 and instruct the moving object 10 to change the route. After that, the process proceeds to step S103.

FIG. 5 is a flow chart showing an example of the operation of the second control circuit 14a in the mobile body 10. As shown in FIG. In this example, the second control circuit 14a performs the following operations after starting movement.
Step S201: Determine whether the obstacle sensor 19 has detected an obstacle. If this determination is Yes, the process moves to step S202. If this determination is No, the process proceeds to step S203.
Step S202: Send a signal to the effect that an obstacle exists to the management device 50, and perform an operation to avoid the obstacle.
Step S<b>203 : It is determined whether a route change instruction has been received from the management device 50 . If this determination is Yes, the process proceeds to step S204. If this determination is No, the process returns to step S201.
Step S204: Move along the indicated changed route.

The above operation is an example, and the above operation may be modified as appropriate. Several modifications of this embodiment will be described below.

After changing the route, the first control circuit 51 may return the changed route to the original route when a signal indicating that the obstacle has been removed is input. A signal indicating that the obstacle has been removed may be transmitted, for example, from another moving object 10 moving in the vicinity of the location, or may be manually input by an administrator or user.

The first control circuit 51 does not change the route of the moving object 10 that is scheduled to pass through the route on which the obstacle exists when the signal indicating the presence of the obstacle is first transmitted, and does not change the route of the moving object 10 that is scheduled to pass through the route where the obstacle exists. You can leave the avoidance of The first control circuit 51 receives a signal indicating the presence of an obstacle from n moving objects (where n is an integer equal to or greater than 2), or transmits the signal indicating the presence of the obstacle n times. The route of the moving object 10 that is scheduled to pass through the route on which the obstacle exists may be changed only when the obstacle is present. According to such an operation, since the route is changed only when the obstacle exists for a long time, it is avoided that the route is changed frequently when the obstacle exists for a short time.

Each moving body 10 compares the laser range finder, the storage device holding the environmental map, and the data output from the laser range finder with the environmental map to determine the position and orientation of the moving body 10 on the environmental map. A position estimator for determining and outputting an estimate may also be included. In this case, the second control circuit 14a moves the moving object 10 based on the position and orientation estimated values output from the position estimation device and the signal indicating the travel route transmitted from the first control circuit 54. .

The first control circuit 54 may transmit the environment map to each moving body 10, or may instruct updating of the environment map depending on the situation. For example, the first control circuit 54 determines whether the obstacle has been removed within a certain period of time (for example, within several hours to several days) after a signal indicating the presence of the obstacle is transmitted from one of the plurality of mobile bodies 10. If no signal indicating that is input, each moving body 10 may be instructed to update the environment map including the obstacle information.

A more specific example in which the mobile body is an automatic guided vehicle will be described below. In the following description, an abbreviation is used to describe an automatic guided vehicle as an "AGV." It should be noted that the following description is equally applicable to moving bodies other than AGVs, such as bipedal or multipedal walking robots, drones, hovercrafts, manned vehicles, and the like, as long as there is no contradiction.

(1) Basic Configuration of System FIG. 6 shows an example of the basic configuration of an exemplary mobile management system 100 according to the present disclosure. The mobile management system 100 includes at least one AGV 10 and an operation management device 50 that manages operation of the AGV 10 . A terminal device 20 operated by the user 1 is also shown in FIG.

The AGV 10 is an unmanned guided vehicle capable of "guideless" travel that does not require a dielectric such as a magnetic tape for travel. The AGV 10 can estimate its own position and transmit the estimation result to the terminal device 20 and the operation management device 50 . The AGV 10 can automatically travel within the moving space S according to a command from the operation management device 50 . The AGV 10 can also operate in a "tracking mode" in which it follows a person or other moving object.

The operation management device 50 is a computer system that tracks the position of each AGV 10 and manages the running of each AGV 10 . The traffic management device 50 can be a desktop PC, a notebook PC, and/or a server computer. The operation management device 50 communicates with each AGV 10 via multiple access points 2 . For example, the operation management device 50 transmits to each AGV 10 the coordinate data of the position to which each AGV 10 should go next. Each AGV 10 periodically transmits data indicating its own position and orientation to the operation management device 50, for example, every 100 milliseconds. When the AGV 10 reaches the instructed position, the operation management device 50 further transmits coordinate data of the position to which the vehicle should go next. The AGV 10 can also travel within the moving space S according to the user's 1 operation input to the terminal device 20 . An example of the terminal device 20 is a tablet computer. Typically, the AGV 10 runs using the terminal device 20 when the map is created, and the AGV 10 runs using the operation control device 50 after the map is created.

FIG. 7 shows an example of a moving space S in which three AGVs 10a, 10b and 10c are present. It is assumed that both AGVs are running in the depth direction in the figure. The AGVs 10a and 10b are in the process of transporting loads placed on the top plate. The AGV 10c is running following the AGV 10b in front. For convenience of explanation, reference numerals 10a, 10b, and 10c are attached in FIG. 7, but are described as "AGV 10" below.

The AGV 10 can also transport a load by using a towing truck connected to itself, in addition to the method of transporting the load placed on the top board. FIG. 8A shows the AGV 10 and towing truck 5 before being connected. Each leg of the tow truck 5 is provided with a caster. The AGV 10 is mechanically connected with the towing truck 5 . FIG. 8B shows the AGV 10 and tow truck 5 connected. When the AGV 10 travels, the tow truck 5 is towed by the AGV 10. - 特許庁By towing the tow truck 5, the AGV 10 can transport the load placed on the tow truck 5. - 特許庁

The connection method between the AGV 10 and the towing truck 5 is arbitrary. An example is described here. A plate 6 is fixed to the top plate of the AGV 10 . The towing carriage 5 is provided with a guide 7 having a slit. The AGV 10 approaches the tow truck 5 and inserts the plate 6 into the slit in the guide 7. When the insertion is completed, the AGV 10 causes an electromagnetic locking pin (not shown) to pass through the plate 6 and the guide 7 to apply an electromagnetic lock. As a result, the AGV 10 and the towing truck 5 are physically connected.

Please refer to FIG. 6 again. Each AGV 10 and the terminal device 20 are connected, for example, one-to-one, and can perform communication conforming to the Bluetooth (registered trademark) standard. Each AGV 10 and terminal device 20 can also perform Wi-Fi (registered trademark) compliant communication using one or a plurality of access points 2 . A plurality of access points 2 are connected to each other via a switching hub 3, for example. FIG. 6 shows two access points 2a and 2b. The AGV 10 is wirelessly connected to the access point 2a. The terminal device 20 is wirelessly connected to the access point 2b. The data transmitted by the AGV 10 is received by the access point 2a, transferred to the access point 2b via the switching hub 3, and transmitted to the terminal device 20 from the access point 2b. Data transmitted by the terminal device 20 is received by the access point 2b, transferred to the access point 2a via the switching hub 3, and transmitted from the access point 2a to the AGV 10. FIG. Thereby, bidirectional communication between the AGV 10 and the terminal device 20 is realized. A plurality of access points 2 are also connected to an operation management device 50 via a switching hub 3 . Thereby, two-way communication is also realized between the operation management device 50 and each AGV 10 .

(2) Creation of environment map A map of the moving space S is created so that the AGV 10 can travel while estimating its own position. The AGV 10 is equipped with a position estimation device and a laser range finder, and the output of the laser range finder can be used to create a map.

The AGV 10 transitions to the data acquisition mode by user's operation. In data acquisition mode, the AGV 10 begins acquiring sensor data using the laser range finder. The laser range finder periodically scans the surrounding space S by radiating, for example, an infrared or visible laser beam to the surroundings. The laser beam is reflected by surfaces such as walls, structures such as pillars, and objects placed on the floor. The laser range finder receives the reflected light of the laser beam, calculates the distance to each reflection point, and outputs measurement result data indicating the position of each reflection point. The position of each reflection point reflects the arrival direction and distance of the reflected light. Data of measurement results is sometimes called "measurement data" or "sensor data".

The position estimation device accumulates sensor data in a storage device. When the acquisition of the sensor data in the movement space S is completed, the sensor data accumulated in the storage device are transmitted to the external device. The external device is, for example, a computer having a signal processor and having a mapping program installed.

A signal processor in the external device superimposes the sensor data obtained for each scan. A map of the space S can be created by repeating the process of superimposition by the signal processor. The external device transmits the created map data to the AGV 10 . The AGV 10 saves the created map data in an internal storage device. The external device may be the operation management device 50 or may be another device.

The AGV 10 may create the map instead of the external device. A circuit such as a microcontroller unit (microcomputer) of the AGV 10 may perform the processing performed by the signal processing processor of the external device described above. When creating a map within the AGV 10, there is no need to transmit the accumulated sensor data to an external device. The data volume of sensor data is generally considered to be large. Since there is no need to transmit sensor data to an external device, occupation of communication lines can be avoided.

It should be noted that the movement within the movement space S for acquiring the sensor data can be realized by the AGV 10 running according to the user's operation. For example, the AGV 10 wirelessly receives a travel command from the user via the terminal device 20 to move in the front, back, left, and right directions. The AGV 10 travels forward, backward, leftward, and rightward in the moving space S according to the travel command to create a map. When the AGV 10 is wired to a control device such as a joystick, the AGV 10 may move forward, backward, left and right in the moving space S according to control signals from the control device to create a map. Sensor data may be acquired by a person pushing a measurement trolley equipped with a laser range finder.

Although a plurality of AGVs 10 are shown in FIGS. 6 and 7, the number of AGVs may be one. When a plurality of AGVs 10 exist, the user 1 can use the terminal device 20 to select one AGV 10 from among the plurality of registered AGVs and create a map of the moving space S.

After the map is created, each AGV 10 can automatically travel while estimating its own position using the map. A description of the process of estimating the self-position will be given later.

(3) Configuration of AGV FIG. 9 is an external view of an exemplary AGV 10 according to this embodiment. The AGV 10 has two driving wheels 11a and 11b, four casters 11c, 11d, 11e and 11f, a frame 12, a carrier table 13, a travel control device 14, and a laser range finder 15. Two drive wheels 11a and 11b are provided on the right and left sides of the AGV 10, respectively. Four casters 11c, 11d, 11e and 11f are arranged at the four corners of the AGV 10. As shown in FIG. It should be noted that the AGV 10 also has multiple motors connected to the two drive wheels 11a and 11b, but the multiple motors are not shown in FIG. FIG. 9 also shows one drive wheel 11a and two casters 11c and 11e positioned on the right side of the AGV 10 and a caster 11f positioned on the left rear, but the left drive wheel 11b and the left front The caster 11d is hidden behind the frame 12 and is not shown. The four casters 11c, 11d, 11e and 11f are freely swivelable. In the following description, the drive wheels 11a and 11b are also referred to as wheels 11a and 11b, respectively.

AGV 10 further comprises at least one obstacle sensor 19 for detecting obstacles. In the example of FIG. 9, four obstacle sensors 19 are provided at four corners of the frame 12 . The number and arrangement of obstacle sensors 19 may differ from the example in FIG. Obstacle sensor 19 may be, for example, a device capable of distance measurement, such as an infrared sensor, an ultrasonic sensor, or a stereo camera. If the obstacle sensor 19 is an infrared sensor, for example, an infrared ray is emitted at regular intervals and the time taken for the reflected infrared ray to return is measured, thereby detecting an obstacle existing within a certain distance. can be done. When the AGV 10 detects an obstacle on the route based on the signal output from at least one obstacle sensor 19, the AGV 10 performs an action to avoid the obstacle.

The travel control device 14 is a device that controls the operation of the AGV 10, and mainly includes an integrated circuit including a microcomputer (described later), electronic components, and a board on which they are mounted. The traveling control device 14 performs data transmission/reception with the terminal device 20 and preprocessing calculations as described above.

The laser range finder 15 is an optical device that measures the distance to a reflection point by emitting an infrared or visible laser beam 15a and detecting the reflected light of the laser beam 15a. In this embodiment, the laser range finder 15 of the AGV 10 emits a pulsed laser beam in a space within a range of 135 degrees to the left and right (270 degrees in total) with respect to the front of the AGV 10, for example, while changing the direction every 0.25 degrees. 15a and detects the reflected light of each laser beam 15a. As a result, it is possible to obtain data on the distance to the reflection point in the direction determined by the angles of 1081 steps in total, every 0.25 degrees. In this embodiment, the scanning of the surrounding space performed by the laser range finder 15 is substantially parallel to the floor surface and planar (two-dimensional). However, the laser range finder 15 may scan in the height direction.

The AGV 10 can create a map of the space S based on the position and orientation (orientation) of the AGV 10 and the scanning result of the laser range finder 15 . The map may reflect the placement of the walls around the AGV, structures such as pillars, and objects placed on the floor. Map data is stored in a storage device provided in the AGV 10 .

Generally, the position and posture of a moving object are called poses. The position and orientation of a moving object in a two-dimensional plane are represented by position coordinates (x, y) in an XY orthogonal coordinate system and an angle θ with respect to the X axis. The position and orientation of the AGV 10, ie pose (x, y, θ), may hereinafter be simply referred to as "position".

The position of the reflection point as seen from the emission position of the laser beam 15a can be expressed using polar coordinates determined by angles and distances. In this embodiment, the laser range finder 15 outputs sensor data expressed in polar coordinates. However, the laser range finder 15 may convert the position expressed in polar coordinates into rectangular coordinates and output the same.

Since the structure and operating principle of laser range finders are well known, no further detailed description is provided herein. Examples of objects that can be detected by the laser range finder 15 are people, luggage, shelves, walls.

The laser range finder 15 is an example of an external sensor for sensing the surrounding space and acquiring sensor data. Image sensors and ultrasonic sensors can be considered as other examples of such external sensors.

The traveling control device 14 can estimate its own current position by comparing the measurement result of the laser range finder 15 and the map data it holds. Note that the stored map data may be map data created by another AGV 10 .

FIG. 10A shows a first hardware configuration example of the AGV 10. As shown in FIG. FIG. 10A also shows a specific configuration of the travel control device 14. As shown in FIG.

The AGV 10 includes a travel control device 14, a laser range finder 15, two motors 16a and 16b, a driving device 17, wheels 11a and 11b, and two rotary encoders 18a and 18b.

The traveling control device 14 has a microcomputer 14a, a memory 14b, a storage device 14c, a communication circuit 14d, and a position estimation device 14e. The microcomputer 14a, the memory 14b, the storage device 14c, the communication circuit 14d, and the position estimation device 14e are connected by a communication bus 14f, and can exchange data with each other. The laser range finder 15 is also connected to the communication bus 14f via a communication interface (not shown), and transmits measurement data, which are measurement results, to the microcomputer 14a, the position estimation device 14e and/or the memory 14b. The microcomputer 14a also functions as the second control circuit 14a shown in FIG.

The microcomputer 14a is a processor or control circuit (computer) that performs calculations for controlling the entire AGV 10 including the travel control device 14. FIG. The microcomputer 14a is typically a semiconductor integrated circuit. The microcomputer 14a transmits a PWM (Pulse Width Modulation) signal, which is a control signal, to the driving device 17 to control the driving device 17 and adjust the voltage applied to the motor. This causes each of the motors 16a and 16b to rotate at the desired rotational speed.

One or more control circuits (for example, microcomputers) for controlling the driving of the left and right motors 16a and 16b may be provided independently of the microcomputer 14a. For example, the motor driving device 17 may include two microcomputers that respectively control the driving of the motors 16a and 16b. These two microcomputers may perform coordinate calculations using encoder information output from encoders 18a and 18b, respectively, to estimate the movement distance of AGV 10 from a given initial position. Also, the two microcomputers may control the motor drive circuits 17a and 17b using the encoder information.

The memory 14b is a volatile storage device that stores computer programs executed by the microcomputer 14a. The memory 14b can also be used as a work memory when the microcomputer 14a and the position estimation device 14e perform calculations.

The storage device 14c is a non-volatile semiconductor memory device. However, the storage device 14c may be a magnetic recording medium typified by a hard disk, or an optical recording medium typified by an optical disc. Further, the storage device 14c may include a head device for writing data to and/or reading data from any recording medium and a control device for the head device.

The storage device 14c stores map data M of the space S in which the vehicle travels, and data R of one or more travel routes (travel route data). The map data M are created by the AGV 10 operating in the map creation mode and stored in the storage device 14c. The travel route data R is transmitted from the outside after the map data M is created. Although the map data M and the travel route data R are stored in the same storage device 14c in this embodiment, they may be stored in different storage devices.

An example of travel route data R will be described.

If the terminal device 20 is a tablet computer, the AGV 10 receives travel route data R indicating a travel route from the tablet computer. The travel route data R at this time includes marker data indicating the positions of a plurality of markers. A "marker" indicates a passing position (way point) of the traveling AGV 10 . The travel route data R includes at least position information of a start marker indicating a travel start position and an end marker indicating a travel end position. The travel route data R may further include position information of markers of one or more intermediate waypoints. When the travel route includes one or more intermediate waypoints, the route from the start marker to the end marker via the travel waypoints in order is defined as the travel route. The data of each marker can include the direction (angle) and travel speed data of the AGV 10 until it moves to the next marker, in addition to the coordinate data of that marker. When the AGV 10 temporarily stops at the position of each marker and performs self-position estimation and notification to the terminal device 20, etc., the data of each marker is the acceleration time required for acceleration to reach the running speed, and / or , data of the deceleration time required for deceleration from the running speed to stop at the position of the next marker.

The movement of the AGV 10 may be controlled by the operation management device 50 (eg, PC and/or server computer) instead of the terminal device 20 . In that case, the operation management device 50 may instruct the AGV 10 to move to the next marker each time the AGV 10 reaches the marker. For example, the AGV 10 receives, from the operation control device 50, the coordinate data of the next target position, or the data of the distance to the target position and the angle to be traveled, as the travel route data R indicating the travel route.

The AGV 10 can travel along the stored travel route while estimating its own position using the created map and the sensor data output by the laser range finder 15 acquired during travel.

The communication circuit 14d is, for example, a wireless communication circuit that performs wireless communication conforming to the Bluetooth (registered trademark) and/or Wi-Fi (registered trademark) standards. Both standards include wireless communication standards using frequencies in the 2.4 GHz band. For example, in a mode in which the AGV 10 is driven to create a map, the communication circuit 14d performs wireless communication conforming to the Bluetooth (registered trademark) standard and communicates with the terminal device 20 on a one-to-one basis.

The position estimation device 14e performs map creation processing and self-position estimation processing during travel. The position estimation device 14e creates a map of the moving space S based on the position and orientation of the AGV 10 and the scan result of the laser range finder. During traveling, the position estimation device 14e receives sensor data from the laser range finder 15, and reads map data M stored in the storage device 14c. By matching the local map data (sensor data) created from the scanning result of the laser range finder 15 with the wider map data M, the self-position (x, y, θ) on the map data M is determined. identify. The position estimator 14e generates "reliability" data representing the extent to which the local map data matches the map data M. FIG. Self-position (x, y, θ) and reliability data can be transmitted from the AGV 10 to the terminal device 20 or the operation management device 50 . The terminal device 20 or the operation management device 50 can receive the self-position (x, y, θ) and reliability data and display them on a built-in or connected display device.

In this embodiment, the microcomputer 14a and the position estimation device 14e are separate components, but this is just an example. A single chip circuit or semiconductor integrated circuit capable of independently performing each operation of the microcomputer 14a and the position estimation device 14e may be used. FIG. 10A shows chip circuitry 14g that encompasses microcomputer 14a and position estimator 14e. An example in which the microcomputer 14a and the position estimation device 14e are provided independently will be described below.

Two motors 16a and 16b are attached to the two wheels 11a and 11b respectively to rotate each wheel. That is, the two wheels 11a and 11b are drive wheels respectively. Motors 16a and 16b are described herein as being motors that drive the right and left wheels of AGV 10, respectively.

The moving body 10 further comprises an encoder unit 18 for measuring the rotational positions or rotational speeds of the wheels 11a and 11b. The encoder unit 18 includes a first rotary encoder 18a and a second rotary encoder 18b. The first rotary encoder 18a measures rotation at any position of the power transmission mechanism from the motor 16a to the wheels 11a. The second rotary encoder 18b measures rotation at any position of the power transmission mechanism from the motor 16b to the wheels 11b. The encoder unit 18 transmits signals obtained by the rotary encoders 18a and 18b to the microcomputer 14a. The microcomputer 14a may control the movement of the moving body 10 using not only the signal received from the position estimation device 14e but also the signal received from the encoder unit 18. FIG.

The drive device 17 has motor drive circuits 17a and 17b for adjusting the voltage applied to each of the two motors 16a and 16b. Each of motor drive circuits 17a and 17b includes a so-called inverter circuit. The motor drive circuits 17a and 17b turn on or off the current flowing through each motor according to the PWM signal sent from the microcomputer 14a or the microcomputer in the motor drive circuit 17a, thereby adjusting the voltage applied to the motor.

FIG. 10B shows a second hardware configuration example of the AGV 10. As shown in FIG. The second hardware configuration example differs from the first hardware configuration example (FIG. 10A) in that it has a laser positioning system 14h and that the microcomputer 14a is connected to each component on a one-to-one basis. do.

The laser positioning system 14 h has a position estimation device 14 e and a laser range finder 15 . The position estimation device 14e and the laser range finder 15 are connected, for example, by an Ethernet (registered trademark) cable. Each operation of the position estimation device 14e and the laser range finder 15 is as described above. The laser positioning system 14h outputs information indicating the pose (x, y, θ) of the AGV 10 to the microcomputer 14a.

The microcomputer 14a has various general-purpose I/O interfaces or general-purpose input/output ports (not shown). The microcomputer 14a is directly connected to other components in the travel control device 14, such as the communication circuit 14d and the laser positioning system 14h, via the general-purpose input/output port.

The configuration is common to that of FIG. 10A except for the configuration described above with respect to FIG. 10B. Therefore, the description of the common configuration is omitted.

The AGV 10 in embodiments of the present disclosure may include safety sensors, such as bumper switches, not shown. The AGV 10 may be equipped with an inertial measurement device such as a gyro sensor. Using data measured by internal sensors such as rotary encoders 18a and 18b or an inertial measurement device, it is possible to estimate the movement distance and attitude change amount (angle) of the AGV 10 . These range and angle estimates are referred to as odometry data and may serve to supplement the position and attitude information obtained by the position estimator 14e.

(4) Map data FIGS. 11A to 11F schematically show the AGV 10 moving while acquiring sensor data. The user 1 may manually move the AGV 10 while operating the terminal device 20 . 10A and 6B, or the AGV 10 itself may be placed on a truck, and the user 1 may manually push or pull the truck to acquire sensor data.

FIG. 11A shows the AGV 10 using a laser range finder 15 to scan the surrounding space. A laser beam is emitted at each predetermined step angle to perform scanning. It should be noted that the illustrated scan range is an example schematically shown, and is different from the total scan range of 270 degrees described above.

In each of FIGS. 11A to 11F, the positions of the reflection points of the laser beam are schematically indicated using a plurality of black dots 4 represented by symbols "·". The scanning of the laser beam is performed at short intervals while the position and posture of the laser range finder 15 are changed. Therefore, the actual number of reflection points is much larger than the number of reflection points 4 shown. The position estimating device 14e accumulates the positions of the black spots 4 obtained as the vehicle travels, for example, in the memory 14b. Map data is gradually completed by continuously scanning while the AGV 10 is running. In Figures 11B to 11E, only the scan range is shown for simplicity. The scan range is an example, and differs from the total 270 degree example described above.

A map may be created using the microcomputer 14a in the AGV 10 or an external computer based on the sensor data obtained after acquiring the necessary amount of sensor data for creating the map. Alternatively, a map may be created in real time based on sensor data acquired by the AGV 10 while it is moving.

FIG. 11F schematically shows a portion of the completed map 80. FIG. In the map shown in FIG. 11F, free space is partitioned by Point Clouds corresponding to collections of reflection points of laser beams. Another example of a map is an occupancy grid map that distinguishes between space occupied by objects and free space by grid units. The position estimation device 14e accumulates map data (map data M) in the memory 14b or the storage device 14c. Note that the illustrated number or density of black dots is an example.

The map data thus obtained can be shared by multiple AGVs 10 .

A typical example of an algorithm by which the AGV 10 estimates its own position based on map data is ICP (Iterative Closest Point) matching. As described above, by matching the local map data (sensor data) created from the scanning result of the laser range finder 15 with the wider map data M, the self-position (x, y, θ) can be estimated.

When the area in which the AGV 10 travels is large, the data amount of the map data M increases. Therefore, there is a possibility that problems such as an increase in map creation time and a long time required for self-position estimation may occur. If such an inconvenience occurs, the map data M may be created and recorded by dividing it into a plurality of partial map data.

FIG. 12 shows an example in which a combination of four pieces of partial map data M1, M2, M3, and M4 covers an entire floor of one factory. In this example, one piece of partial map data covers an area of 50m x 50m. A rectangular overlapping area with a width of 5 m is provided at the boundary between two adjacent maps in each of the X and Y directions. This overlapping area is called a "map switching area". When the AGV 10 traveling while referring to one partial map reaches a map switching area, the AGV 10 switches to traveling while referring to another adjacent partial map. The number of partial maps is not limited to four, and may be set as appropriate according to the area of the floor on which the AGV 10 runs, and the performance of the computer that executes map creation and self-position estimation. The size of the partial map data and the width of the overlapping area are also not limited to the above examples, and may be set arbitrarily.

(5) Configuration Example of Operation Management Device FIG. 13 shows an example of the hardware configuration of the operation management device 50 . The operation management device 50 has a CPU 51 , a memory 52 , a position database (position DB) 53 , a communication circuit 54 , a map database (map DB) 55 and an image processing circuit 56 .

The CPU 51, memory 52, position DB 53, communication circuit 54, map DB 55, and image processing circuit 56 are connected by a communication bus 57, and can exchange data with each other.

The CPU 51 is a signal processing circuit (computer) that controls the operation of the operation management device 50 . The CPU 51 is typically a semiconductor integrated circuit. The CPU 51 functions as the first control circuit 51 shown in FIG.

The memory 52 is a volatile storage device that stores computer programs executed by the CPU 51 . The memory 52 can also be used as a work memory when the CPU 51 performs calculations.

The position DB 53 stores position data indicating each potential destination of each AGV 10 . The position data may be represented by coordinates set virtually within the factory by an administrator, for example. Location data is determined by an administrator.

Communication circuit 54 performs wired communication conforming to the Ethernet (registered trademark) standard, for example. The communication circuit 54 is connected to the access point 2 ( FIG. 1 ) by wire, and can communicate with the AGV 10 via the access point 2 . The communication circuit 54 receives data to be transmitted to the AGV 10 from the CPU 51 via the bus 57 . The communication circuit 54 also transmits data (notification) received from the AGV 10 to the CPU 51 and/or the memory 52 via the bus 57 .

The map DB 55 stores map data of the inside of a factory or the like where the AGV 10 travels. The map may be the same as map 80 (FIG. 11F) or may be different. The data format does not matter as long as the map has a one-to-one correspondence with the position of each AGV 10 . For example, the map stored in the map DB 55 may be a map created by CAD.

The position DB 53 and the map DB 55 may be constructed on a non-volatile semiconductor memory, or may be constructed on a magnetic recording medium typified by a hard disk, or an optical recording medium typified by an optical disc.

The image processing circuit 56 is a circuit that generates image data to be displayed on the monitor 58 . The image processing circuit 56 operates exclusively when the manager operates the operation management device 50 . In this embodiment, a more detailed description is omitted. Note that the monitor 59 may be integrated with the operation management device 50 . Alternatively, the processing of the image processing circuit 56 may be performed by the CPU 51 .

(6) Operation of Operation Management Device An outline of the operation of the operation management device 50 will be described with reference to FIG. FIG. 14 is a diagram schematically showing an example of the moving route of the AGV 10 determined by the operation management device 50. As shown in FIG.

An overview of the operations of the AGV 10 and the operation management device 50 is as follows. Below is an example in which an AGV 10 is currently at a point (marker) M1, passes through several positions, and travels to its final destination, a marker _{Mn+1 (} n: a positive integer equal to or greater than 1). explain. Note that the position DB 53 records coordinate data indicating the respective positions of the marker M ₂ to be passed next to the marker M ₁ , the marker M ₃ to be passed next to the marker M ₂ , and the like.

The CPU 51 of the operation management device 50 refers to the position DB 53, reads the coordinate data of the marker _M2 , and generates a travel command to direct the vehicle to the marker _M2 . A communication circuit 54 transmits a travel command to the AGV 10 via the access point 2 .

The CPU 51 periodically receives data indicating the current position and orientation from the AGV 10 via the access point 2 . In this way, the operation management device 50 can track the position of each AGV 10 . When the CPU 51 determines that the current position of the AGV 10 matches the marker M ₂ , the CPU 51 reads the coordinate data of the marker M ₃ , generates a travel command to move the marker M ₃ , and transmits it to the AGV 10 . That is, when the operation management device 50 determines that the AGV 10 has reached a certain position, it transmits a travel command to direct the AGV 10 to the position to be passed next. This allows the AGV 10 to reach its final destination, marker _Mn+1 .

The mobile body and mobile body management system of the present disclosure can be suitably used for moving and transporting goods such as packages, parts, and finished products in factories, warehouses, construction sites, logistics, hospitals, and the like.

1... User, 2a, 2b... Access point, 10... AGV (moving body), 14... Driving control device, 14a... Microcomputer (second control circuit), 14b... Memory , 14c... storage device, 14d... communication circuit (second communication circuit), 14e... position estimation device, 16a, 16b... motor, 15... laser range finder, 17... drive Device 17a, 17b Motor drive circuit 18 Encoder unit 18a, 18b Rotary encoder 19 Obstacle sensor 20 Terminal device (mobile computer such as tablet computer) , 50... Operation management device, 51... CPU (first control circuit), 52... Memory, 53... Position database (position DB), 54... Communication circuit (first communication circuit) , 55... Map database (map DB), 56... Image processing circuit, 100... Mobile object management system, 101... Mobile object, 103... External sensor, 105... Position estimation device , 107... storage device, 109... controller, 111... drive device

Claims (5)

A management device for managing the operation of a plurality of autonomously movable moving bodies,
a first communication circuit communicating with each of the plurality of mobile bodies;
a first control circuit that determines a travel route for each of the plurality of mobile bodies and transmits a signal indicating the travel route to each of the plurality of mobile bodies via the first communication circuit;
with
each of the plurality of moving bodies,
a second communication circuit communicating with the first communication circuit;
at least one sensor for detecting obstacles;
A second control circuit for moving the moving body along the travel route determined by the first control circuit, wherein when the sensor detects an obstacle, the moving body avoids the obstacle, a second control circuit that transmits a signal indicating the presence of an obstacle via the second communication circuit;
with
The first control circuit is
when the signal indicating the presence of the obstacle is transmitted from any one of the plurality of mobile bodies,
changing a route of one of the plurality of mobile bodies that is scheduled to pass through the route on which the obstacle exists ;
The first control circuit is
without changing the route of the moving object that is scheduled to pass through the route on which the obstacle exists when the signal indicating the presence of the obstacle is first transmitted;
A route of a moving object that is scheduled to pass through a route on which said obstacle exists only when said signal indicating the existence of said obstacle is transmitted from n moving objects (where n is an integer equal to or greater than 2). A management device that changes the A management device that manages the operation of a plurality of autonomously movable moving bodies,
a first communication circuit communicating with each of the plurality of mobile bodies;
a first control circuit that determines a travel route for each of the plurality of mobile bodies and transmits a signal indicating the travel route to each of the plurality of mobile bodies via the first communication circuit;
with
each of the plurality of moving bodies,
a second communication circuit communicating with the first communication circuit;
at least one sensor for detecting obstacles;
A second control circuit for moving the moving body along the travel route determined by the first control circuit, wherein when the sensor detects an obstacle, the moving body avoids the obstacle, a second control circuit that transmits a signal indicating the presence of an obstacle via the second communication circuit;
with
The first control circuit is
when the signal indicating the presence of the obstacle is transmitted from any one of the plurality of mobile bodies,
changing a route of one of the plurality of mobile bodies that is scheduled to pass through the route on which the obstacle exists;
Each moving body
a laser range finder,
a storage device holding an environment map;
a position estimation device that determines and outputs estimated values of the position and orientation of the mobile object on the environmental map by comparing the data output from the laser range finder with the environmental map;
further comprising
The second control circuit controls the estimated value output from the position estimation device and the first control circuit.
moving the mobile object based on the signal indicating the travel route transmitted from the road;
When a signal indicating that the obstacle has been removed is not input within a certain period of time after the signal indicating the presence of the obstacle has been transmitted from any of the plurality of mobile bodies,
The management device, wherein the first control circuit instructs each moving body to update the environment map including the information on the obstacle. The signal indicating the travel route includes information indicating the positions of a plurality of points on the route from the initial position to the target position,
the signal indicating the presence of the obstacle includes information indicating the position of the obstacle;
When the signal indicating the presence of the obstacle is transmitted from any one of the plurality of moving bodies, and the position of the obstacle is between two adjacent points among the plurality of points,
The first control circuit changes a route of a moving object, which is scheduled to pass through a route including the two points, from among the plurality of moving objects to a route that does not include the two points.
The management device according to claim 1 or 2 . 4. The management device according to any one of claims 1 to 3 , wherein said first control circuit returns the changed route to the original route when a signal indicating that said obstacle has been removed is input. a management device according to any one of claims 1 to 4 ;
a plurality of moving bodies;
A mobile system comprising:

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