Patent Publication Number: US-2022217925-A1

Title: Working machine

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to and the benefit of Japanese Patent Application No. 2021-003010 filed on Jan. 12, 2021, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a working machine. 
     Description of the Related Art 
     As one of work machines that perform work such as maintenance of roads and parks, a work machine (blower) that moves (collects) fallen leaves scattered on roads and grass clippings in parks is known. Additionally, International Publication No. 2018/182944 proposes a technique of using a drone (unmanned aerial vehicle) in a work machine that performs pest control work. 
     On the other hand, in recent years, research and development of a technique related to an autonomous work machine having a function of performing work by automatically and autonomously traveling (autonomously traveling) in a work area without requiring operation by a worker have been advanced for various work machines. In such an autonomous work machine, as disclosed in International Publication No. 2018/182944, for example, a technique for further improving work efficiency by using a drone or the like is required. 
     SUMMARY OF THE INVENTION 
     The present invention provides a new technique related to a work machine. 
     According to one aspect of the present invention, there is provided an autonomous work machine comprising: a main body portion; an air blowing portion that is provided in the main body portion and ejects air toward a work plane to generate an airflow; a first acquisition portion that acquires scattered object information regarding scattered objects present in a work area; a second acquisition portion that acquires target information regarding a target position for moving the scattered objects; and a control portion that controls the air blowing portion on the basis of the scattered object information acquired by the first acquisition portion and the target information acquired by the second acquisition portion, wherein the control portion controls a direction and an amount of the air ejected by the air blowing portion so that the scattered objects are moved to the target position by the airflow generated by the air blowing portion. 
     Further aspects of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a configuration of a work machine according to a first embodiment of the present invention. 
         FIG. 2  is a diagram illustrating an example of a configuration of a control portion of the work machine illustrated in  FIG. 1 . 
         FIG. 3  is a diagram schematically illustrating an example of an operation of the work machine illustrated in  FIG. 1 . 
         FIG. 4  is a diagram schematically illustrating an example of an operation of the work machine illustrated in  FIG. 1 . 
         FIGS. 5A and 5B  are diagrams schematically illustrating an example of an operation of the work machine illustrated in  FIG. 1 . 
         FIG. 6  is a schematic view illustrating a configuration of a work machine according to a second embodiment of the present invention. 
         FIG. 7  is a schematic view illustrating a configuration of a work machine according to a third embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made to an invention that requires a combination of all features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. 
     First Embodiment 
       FIG. 1  is a schematic view illustrating a configuration of a work machine  1 A according to a first embodiment of the present invention, and is a side view of the work machine  1 A. Note that in each drawing including  FIG. 1 , a coordinate axis X indicates a front-and-rear direction (traveling direction) of the work machine  1 A, a coordinate axis Y indicates a width direction of the work machine  1 A, and a coordinate axis Z indicates a vertical direction (height direction) of the work machine  1 A. 
     The work machine  1 A is an autonomous work machine having a function of performing predetermined work by automatically and autonomously traveling (autonomously traveling) in a work area without requiring operation by a worker, that is, an autonomous working robot. The work machine  1 A is embodied as a work machine, a so-called blower, that performs work of moving (collecting) scattered objects present in a work area such as a road or a park as predetermined work. Scattered objects are objects to be moved in the work area or objects to be removed from the work area, and in the present embodiment, fallen leaves, grass clippings, and the like are assumed. Note, however, that scattered objects are not limited thereto, and include snow, for example. As illustrated in  FIG. 1 , the work machine  1 A includes a main body portion  10 , a traveling portion  20 , a detection portion  30 , an area monitoring portion  40 , a setting portion  50 , an environment monitoring portion  60 , a communication portion  70 , an air blowing portion  80 , and a control portion  90 . 
     The main body portion  10  forms an outer surface of the work machine  1 A. The main body portion  10  includes, for example, a frame that is a framework of the work machine  1 A and a housing (outer surface) that covers an internal space (accommodation space) defined by the frame. 
     The traveling portion  20  has a function of causing the work machine  1 A to travel, and in the present embodiment, moves the main body portion  10  along a work plane WP of a work area. The traveling portion  20  is provided in the main body portion  10 , and includes front wheels  22  disposed on the front left side and the front right side of the work machine  1 A and functioning as driven wheels, and rear wheels  24  disposed on the rear left side and the rear right side of the work machine  1 A and functioning as drive wheels, as wheels rotatably contacting the work plane WP. Additionally, the traveling portion  20  includes a motor  26  that drives the rear wheels  24  so as to move the main body portion  10  along the work plane WP. In the present embodiment, the work machine  1 A (main body portion  10 ) is supported by four wheels of the front wheels  22  and the rear wheels  24 . When the motor  26  drives (rotates) the rear wheels  24 , the work machine  1 A can be made to travel along the work plane WP. Note, however, that the traveling portion  20  is not an essential requirement for the work machine  1 A as described later. 
     The detection portion  30  is provided in the main body portion  10  and has a function of detecting various types of information regarding traveling of the work machine  1 A. The detection portion  30  includes, for example, a current sensor that detects the load of the motor  26  of the traveling portion  20 , a GPS sensor that detects the position of the work machine  1 A, and a G sensor, a vehicle speed sensor, an angular velocity sensor, and the like that detect the attitude, the vehicle speed, the angular velocity, and the like (state of work machine  1 A) of the work machine  1 A. 
     The area monitoring portion  40  is provided in the main body portion  10 , and has a function of monitoring the work area of the work machine  1 A and acquiring various types of information regarding the work area. The area monitoring portion  40  monitors, for example, whether scattered objects are present in the work area, and if scattered objects are present in the work area, acquires information (scattered object information) regarding the scattered objects. As described above, in the present embodiment, the area monitoring portion  40  functions as a first acquisition portion that acquires scattered object information regarding scattered objects present in the work area. The area monitoring portion  40  acquires, as scattered object information regarding scattered objects, information indicating the position of the scattered objects present in the work area and information indicating the amount of the scattered objects at the position (i.e., position where scattered objects are present). The area monitoring portion  40  includes a detection unit that detects the state of the work area, and specifically includes, as the detection unit, an infrared sensor and a camera that detect scattered objects (e.g., fallen leaves and grass clippings) present in the work area. Additionally, the area monitoring portion  40  can also detect an obstacle (e.g., stone) in the work area. 
     The setting portion  50  includes a display device such as a liquid crystal display (LCD) or an organic light emitting diode (OLED), and an input device such as a button and an operation key. In the present embodiment, the setting portion  50  is configured as a touch panel provided in the main body portion  10 , displays (provides) various graphical user interfaces (GUIs) including a setting screen, a selection screen, and the like, and accepts operations on the GUIs (various settings for work machine  1 A). The worker sets a target position to which the scattered objects present in the work area are moved, through (GUI displayed on) the setting portion  50 . Additionally, the worker may set, as a destination to move the scattered objects, the target position itself or a direction headed toward the target position (target direction). As described above, in the present embodiment, the setting portion  50  functions as a second acquisition portion that acquires target information (i.e., information indicating target position and information indicating target direction) regarding a target position for moving scattered objects. 
     The environment monitoring portion  60  is provided in the main body portion  10 , and functions as a third acquisition portion that monitors the environment around the work machine  1 A (work area) and acquires environment information regarding the environment of the work area. The environment monitoring portion  60  acquires, as environment information regarding the environment of the work area, information indicating the direction of wind (wind direction) in the work area and information indicating the position of a person present in the work area. The environment monitoring portion  60  includes a detection unit that detects the environment of the work area, and specifically includes, as the detection unit, an anemoscope and an anemometer that detect the wind direction and the wind speed in the work area, and an infrared sensor and a camera that detect a person present in the work area. Note that some functions (e.g., function of detecting person) of the environment monitoring portion  60  may be integrated with some functions (e.g., function of detecting scattered objects or obstacle) of the area monitoring portion  40 . 
     The communication portion  70  communicates with an external device such as another work machine through wireless communication such as Bluetooth (registered trademark), and acquires various types of information regarding the other work machine. In the present embodiment, the communication portion  70  communicates with another work machine and acquires route information indicating a route (work route) along which the other work machine moves from the other work machine. 
     The air blowing portion  80  functions as a work unit that actually performs work of moving scattered objects present in the work area to a target position. The air blowing portion  80  is provided in the main body portion  10 , and ejects air toward the work plane WP to generate an airflow AF so as to levitate the work machine  1 A (main body portion  10 ). In the present embodiment, the air blowing portion  80  includes a blade member  81 , a rotary motor  82 , a duct  83 , an air inlet  84 , and an air outlet  85 . The blade member  81  is attached to a rotation shaft  82   a  of the rotary motor  82 , and includes, for example, blades extending in the radial direction about the rotation shaft  82   a . The rotary motor  82  rotates the rotation shaft  82   a  to rotate the blade member  81  about the rotation shaft  82   a . The duct  83  connects the air inlet  84  and the air outlet  85 , and accommodates the blade member  81  therein (between air inlet  84  and air outlet  85 ). Additionally, by providing the air inlet  84  in the vicinity of the motor  26 , the motor  26  as a heat source can be cooled by the air taken into the duct  83  from the air inlet  84 . 
     In the air blowing portion  80 , when the rotary motor  82  rotates the blade member  81 , outside air is taken into the duct  83  from the air inlet  84 . The air taken into the duct  83  is sent to the blade member  81  located downstream of the air inlet  84 , and compressed (pressurized) by the rotation of the blade member  81 . The air compressed by the blade member  81  is ejected onto the work plane WP from the air outlet  85  located downstream of the blade member  81 , and forms the airflow AF from the air outlet  85  toward the work plane WP. The air blowing portion  80  continuously compresses air taken in from the air inlet  84  and injects the air onto the work plane WP below the work machine  1 A (main body portion  10 ) (i.e., continuously forms airflow AF by compressed air), thereby applying a levitating force to the work machine  1 A. Accordingly, the work machine  1 A can be levitated by the airflow AF generated by the air blowing portion  80 . 
     Additionally, as a mechanism for changing the direction of air injected from the air outlet  85 , that is, the direction of air injected by the air blowing portion  80 , in the present embodiment, a change mechanism  86  for changing the direction (attitude) of the blade member  81  with respect to the work plane WP is provided in the air blowing portion  80 . As indicated by arrows in  FIG. 1 , the change mechanism  86  has a function of rotating the blade member  81  with at least two axes along the front-and-rear direction (X direction) of the work machine  1 A and the width direction (Y direction) of the work machine  1 A as rotation axes. The direction of the airflow AF can be changed by changing the direction of the blade member  81  with respect to the work plane WP through the change mechanism  86 . It is also possible to apply a propulsive force to the work machine  1 A (main body portion  10 ) by forming the airflow AF in the front-and-rear direction or the left-and-right direction of the work machine  1 A, for example. In other words, the air blowing portion  80  can generate the airflow AF so as to move the work machine  1 A along the work plane WP in cooperation with the change mechanism  86 . In this case, since the air blowing portion  80  also has a function of causing the work machine  1 A to travel, as described above, the work machine  1 A does not necessarily have to include the traveling portion  20 . Additionally, the air blowing portion  80  or the traveling portion  20  may be used supplementarily to cause the work machine  1 A to travel. Furthermore, a function of causing the work machine  1 A to travel may be achieved by the air blowing portion  80 , and it is possible to provide only the front wheels  22  and the rear wheels  24  in the work machine  1 A as assistance of such travel. 
     The control portion  90  is an electronic control unit (ECU), and includes a central processing unit (CPU)  92 , a memory  94 , and a storage  96  as illustrated in  FIG. 2 .  FIG. 2  is a diagram illustrating an example of a configuration of the control portion  90 . The CPU  92  controls each portion of the work machine  1 A by developing a program stored in the storage  96  in the memory  94  and executing the program. Note that the function of the control portion  90  may be implemented by a semiconductor integrated circuit such as a programmable logic device (PLD) or an application specific integrated circuit (ASIC), or may be implemented by software. In other words, the function of the control portion  90  can be implemented by both hardware and software. 
     In the present embodiment, the CPU  92  functions as a travel control portion  922  and a work control portion  924 . For example, the CPU  92  functions as the travel control portion  922  to control the traveling portion  20  (or air blowing portion  80 ) on the basis of various types of information detected by the detection portion  30 , and functions as the work control portion  924  to control the air blowing portion  80  on the basis of various types of information acquired by the area monitoring portion  40 , the setting portion  50 , and the environment monitoring portion  60 . As a result, a function of performing work of automatically and autonomously traveling in the work area and moving scattered objects without requiring operation by the worker is achieved. Note that in the following description, in order to facilitate the description, the control portion  90  will be described as the control subject. 
     The control portion  90  integrally controls each portion of the work machine  1 A to operate the work machine  1 A. In the present embodiment, the control portion  90  controls the air blowing portion  80  on the basis of scattered object information acquired by the area monitoring portion  40  and target information acquired by the setting portion  50 . For example, the control portion  90  first specifies a target position, which is a destination to which the scattered objects are to be moved, from target information acquired by the setting portion  50 . Next, while controlling the traveling portion  20  to cause the work machine  1 A to travel in the work area, the control portion  90  controls the area monitoring portion  40  to acquire scattered object information regarding scattered objects present in the work area. Next, based on the scattered object information acquired by the area monitoring portion  40 , the control portion  90  causes the traveling portion  20  to move the work machine  1 A to a position where the scattered objects are present in the work area. Then, as illustrated in  FIG. 3 , the control portion  90  controls the direction and amount of air (compressed air) ejected by the air blowing portion  80  such that the scattered objects are moved to the target position by the airflow AF generated by the air blowing portion  80 .  FIG. 3  is a diagram schematically illustrating an example of an operation (work) of the work machine  1 A. As described above, by controlling the direction and amount of air injected by the air blowing portion  80  from the positional relationship between the position of the scattered objects present in the work area and the target position, the scattered objects can be efficiently moved to the target position. Note that as described above, the direction of air ejected by the air blowing portion  80  can be controlled by the change mechanism  86 , and the amount of air injected by the air blowing portion  80  can be controlled by the number of revolutions or the rotation speed (i.e., output of rotary motor  82 ) of the blade member  81 . 
     Additionally, by matching the moving direction when the work machine  1 A is moved to the position where the scattered objects are present in the work area with the direction in which the scattered objects are moved to the target position, it is possible to efficiently perform the work of moving the scattered objects to the target position. This is particularly useful when the air blowing portion  80  is used instead of the traveling portion  20  to move the work machine  1 A. 
     Additionally, it is preferable that the control portion  90  control the air blowing portion  80  such that the larger the amount of scattered objects included in the scattered object information acquired by the area monitoring portion  40 , the larger the amount of air injected by the air blowing portion  80  at the position where the scattered objects are present. As a result, it is possible to reduce the amount of scattered objects that could not be moved to the target position by the airflow AF, that is, the residual amount of scattered objects. 
     Additionally, the control portion  90  may control the traveling portion  20  (motor  26 ) or the air blowing portion  80  such that the larger the amount of scattered objects included in the scattered object information acquired by the area monitoring portion  40 , the slower the moving speed of the work machine  1 A (main body portion  10 ) at the position where the scattered objects are present becomes. As a result, as in the case of increasing the amount of air injected by the air blowing portion  80 , it is possible to reduce the amount of scattered objects that could not be moved to the target position by the airflow AF, that is, the residual amount of scattered objects. 
     It is preferable that the control portion  90  control the direction and amount of air ejected by the air blowing portion  80  so that the scattered objects move to the target position by the airflow AF generated by the air blowing portion  80 , based not only on the scattered object information acquired by the area monitoring portion  40  and the target information acquired by the setting portion  50 , but also environment information acquired by the environment monitoring portion  60 . As a result, it is possible to perform work of moving the scattered objects to the target position according to the environment of the work area. 
     For example, consider a case where environment information includes information indicating a wind direction in the work area. In this case, the control portion  90  can move scattered objects to the target position more efficiently while reducing (preventing) re-scattering of the scattered objects, by controlling the direction and amount of air ejected by the air blowing portion  80  such that the scattered objects move to the target position along the wind direction included in the environment information acquired by the environment monitoring portion  60 . 
     Additionally, a case where environment information includes information indicating a position of a person present in the work area will be considered. In this case, as shown in  FIG. 4 , the control portion  90  controls the direction and amount of air ejected by the air blowing portion  80  such that the scattered objects move to the target position while avoiding the position of a person included in the environment information acquired by the environment monitoring portion  60 .  FIG. 4  is a diagram schematically illustrating an example of an operation (work) of the work machine  1 A. As described above, by moving the scattered objects in consideration of people present around the work machine  1 A, it is possible to keep (prevent) the scattered objects from hitting people. 
     In an actual scene, there may be a case where the work of moving scattered objects to the target position is performed not only by one work machine  1 A, but together with a plurality of work machines, that is, other work machines. In such a case, it is preferable that the control portion  90  control the movement of the work machine  1 A using information regarding other work machines acquired by the communication portion  70 . For example, the control portion  90  moves the work machine  1 A (main body portion  10 ) along the work plane WP such that the work machine  1 A does not interfere with other work machines as illustrated in  FIG. 5A , on the basis of route information indicating routes along which other work machines move acquired by the communication portion  70 . As a result, the work machine  1 A can perform the work of moving scattered objects to the target position without disturbing work performed by other work machines, and work efficiency can be improved. Alternatively, based on the route information acquired by the communication portion  70 , as illustrated in  FIG. 5B , the control portion  90  may move the work machine  1 A (main body portion  10 ) along the work plane WP such that the work machine  1 A follows another work machine. As a result, the work machine  1 A can perform work in cooperation with other work machines, and work efficiency can be improved. This is particularly useful because when work performed by the other work machine generates scattered objects, such as when the other work machine performs mowing, the mowed turf that is the scattered objects can be immediately moved to the target position. Furthermore, the work machine  1 A and a plurality of other work machines may perform work in formation (in an orderly manner). Here,  FIGS. 5A and 5B  are diagrams schematically illustrating an example of an operation (work) of the work machine  1 A. 
     As described above, according to the present embodiment, it is possible to provide a work machine that efficiently moves scattered objects present in a work area to a target position. 
     Second Embodiment 
       FIG. 6  is a schematic view illustrating a configuration of a work machine  1 B according to a second embodiment of the present invention, and is a side view of the work machine  1 B. Similarly to the work machine  1 A, the work machine  1 B is embodied as an autonomous work machine, a so-called blower, that performs work of moving (collecting) scattered objects present in a work area such as a road or a park. The work machine  1 B basically has a configuration similar to that of the work machine  1 A, but differs from the work machine  1 A in a mechanism for changing the direction of air injected from an air outlet  85 , that is, the direction of air injected by an air blowing portion  80 . Specifically, in the work machine  1 B, the change mechanism  86  is replaced with a change mechanism  88 . 
     The change mechanism  88  changes the direction (orientation) of the air outlet  85  with respect to a work plane WP. As indicated by an arrow in  FIG. 6 , the change mechanism  88  has a function of rotating the air outlet  85  with at least an axis along the width direction (Y direction) of the work machine  1 B as a rotation axis. Further, the change mechanism  88  preferably has a function of rotating the air outlet  85  with an axis along the front-and-rear direction (X direction) of the work machine  1 B as a rotation axis. The direction of an airflow AF can be changed similarly to the work machine  1  by changing the direction of the air outlet  85  with respect to the work plane WP through the change mechanism  88 . 
     Similarly to the first embodiment, the present embodiment, too, can provide a work machine that efficiently moves scattered objects present in a work area to a target position. 
     Third Embodiment 
       FIG. 7  is a schematic view illustrating a configuration of a work machine  1 C according to a third embodiment of the present invention, and is a side view of the work machine  1 C. Similarly to the work machine  1 A, the work machine  1 C is embodied as an autonomous work machine, a so-called blower, that performs work of moving (collecting) scattered objects present in a work area such as a road or a park. The work machine  1 C basically has a configuration similar to that of the work machine  1 A. Note, however, that the work machine  1 C is different from the work machine  1 A in that the traveling portion  20  is not provided, and the work unit that actually performs the work of moving the scattered objects present in the work area to the target position is different. Specifically, in the work machine  1 C, the air blowing portion  80  is replaced with an air blowing portion  80 C. 
     The air blowing portion  80 C is provided in a main body portion  10 , and ejects air toward a work plane WP to generate an airflow AF so as to levitate and move the work machine  1 C (main body portion  10 ). The air blowing portion  80 C includes a drone (unmanned aerial vehicle) DR, and includes three drones DR in the present embodiment. Note, however, that the number of drones DR configured as the air blowing portion  80 C is not limited. 
     The air blowing portion  80 C includes, as the drone DR, a plurality of (e.g., four) rotary blades (propellers)  802  and a motor  804  that rotates each of the plurality of rotary blades  802 . In the air blowing portion  80 C, when the motor  804  rotates the rotary blade  802 , air compressed by the rotary blade  802  is ejected onto a work plane WP from an air outlet  85  located below the rotary blade  802 , and forms an airflow AF from the air outlet  85  toward the work plane WP. 
     In the present embodiment, the control portion  90  controls the rotation direction and the rotation speed of each of the plurality of rotary blades  802 . As a result, it is possible to control (change) the levitation and movement of the work machine  1 C, that is, the direction of the airflow AF. Accordingly, even when the drone DR is used as the air blowing portion  80 C, it is possible to control the direction and amount of air ejected by the air blowing portion  80 C such that scattered objects are moved to a target position by the airflow AF generated by the air blowing portion  80 C. By controlling the direction and amount of air ejected by the air blowing portion  80  from the positional relationship between the position of the scattered objects present in the work area and the target position, the scattered objects can be efficiently moved to the target position. 
     As described above, similarly to the first embodiment and the second embodiment, the present embodiment, too, can provide a work machine that efficiently moves scattered objects present in a work area to a target position. 
     Summary of Embodiments 
     1. A work machine of the above-described embodiment is an autonomous work machine (e.g.,  1 A,  1 B,  1 C) including: 
     a main body portion (e.g.,  10 ); 
     an air blowing portion (e.g.,  80 ,  80 C) that is provided in the main body portion and ejects air toward a work plane (e.g., WP) to generate an airflow (e.g., AF); 
     a first acquisition portion (e.g.,  40 ) that acquires scattered object information regarding scattered objects present in a work area; 
     a second acquisition portion (e.g.,  50 ) that acquires target information regarding a target position for moving the scattered objects; and 
     a control portion (e.g.,  90 ) that controls the air blowing portion on the basis of the scattered object information acquired by the first acquisition portion and the target information acquired by the second acquisition portion, in which 
     the control portion controls a direction and an amount of the air ejected by the air blowing portion so that the scattered objects are moved to the target position by the airflow generated by the air blowing portion. 
     According to this embodiment, scattered objects can be efficiently moved to the target position. 
     2. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the scattered object information includes information indicating a position of the scattered objects in the work area and information indicating an amount of the scattered objects at the position, and 
     the control portion (e.g.,  90 ) controls the air blowing portion (e.g.,  80 ,  80 C) such that the larger the amount of the scattered objects included in the scattered object information acquired by the first acquisition portion (e.g.,  40 ), the larger the ejection amount at the position of the scattered objects included in the scattered object information. 
     According to this embodiment, it is possible to reduce the amount (residual amount) of scattered objects that could not be moved to the target position by the airflow. 
     3. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the air blowing portion (e.g.,  80 ,  80 C) generates the airflow so as to move the main body portion (e.g.,  10 ) along the work plane (e.g., WP). 
     According to this embodiment, the main body portion can be moved along the work plane. 
     4. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the scattered object information includes information indicating a position of the scattered objects in the work area and information indicating an amount of the scattered objects at the position, and 
     the control portion (e.g.,  90 ) controls the air blowing portion (e.g.,  80 ,  80 C) such that the larger the amount of the scattered objects included in the scattered object information acquired by the first acquisition portion (e.g.,  40 ), the slower a moving speed of the main body portion (e.g.,  10 ) at the position of the scattered objects included in the scattered object information. 
     According to this embodiment, it is possible to reduce the amount (residual amount) of scattered objects that could not be moved to the target position by the airflow. 
     5. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, further including: 
     a wheel (e.g.,  22 ,  24 ) that is provided in the main body portion (e.g.,  10 ) and rotatably contacts the work plane (e.g., WP); and 
     a motor (e.g.,  26 ) that rotates the wheel so as to move the main body portion along the work plane. 
     According to this embodiment, the main body portion can be moved along the work plane. 
     6. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the control portion (e.g.,  90 ) controls the motor (e.g.,  26 ) such that the larger the amount of the scattered objects included in the scattered object information acquired by the first acquisition portion (e.g.,  40 ), the slower a moving speed of the main body portion (e.g.,  10 ) at the position of the scattered objects included in the scattered object information. 
     According to this embodiment, it is possible to reduce the amount (residual amount) of scattered objects that could not be moved to the target position by the airflow. 
     7. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, further including 
     a third acquisition portion (e.g.,  60 ) that acquires environment information regarding an environment of the work area, in which 
     the control portion (e.g.,  90 ) controls the ejection direction and the ejection amount such that the scattered objects are moved to the target position by the airflow generated by the air blowing portion (e.g.,  80 ,  80 C) also based on the environment information acquired by the third acquisition portion. 
     According to this embodiment, it is possible to perform an operation of moving scattered objects to the target position according to the environment of the work area. 
     8. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the environment information includes information indicating a wind direction in the work area, and 
     the control portion (e.g.,  90 ) controls the ejection direction and the ejection amount such that the scattered objects move to the target position along the wind direction included in the environment information acquired by the third acquisition portion (e.g.,  60 ). 
     According to this embodiment, it is possible to more efficiently move the scattered objects to the target position while curbing re-scattering of the scattered objects. 
     9. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the environment information includes information indicating a position of a person present in the work area, and 
     the control portion (e.g.,  90 ) controls the ejection direction and the ejection amount such that the scattered objects move to the target position while avoiding the position of a person included in the environment information acquired by the third acquisition portion (e.g.,  60 ). 
     According to this embodiment, it is possible to keep scattered objects from hitting people. 
     10. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, further including 
     a communication portion (e.g.,  70 ) that communicates with another work machine, in which 
     the communication portion acquires route information indicating a route along which the other work machine moves from the other work machine, and 
     the control portion (e.g.,  90 ) moves the main body portion (e.g.,  10 ) along the work plane (e.g., WP) so as not to interfere with the other work machine on the basis of the route information acquired by the communication portion. 
     According to this embodiment, it is possible to perform the work of moving scattered objects to the target position without disturbing work performed by other work machines, and work efficiency can be improved. 
     11. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the control portion (e.g.,  90 ) moves the main body portion (e.g.,  10 ) along the work plane (e.g., WP) so as to follow the other work machine. 
     According to this embodiment, work can be performed in cooperation with other work machines, and work efficiency can be improved. 
     12. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, further including 
     a change mechanism (e.g.,  86 ,  88 ) that changes the direction of the air ejected by the air blowing portion (e.g.,  80 ,  80 C). 
     According to this embodiment, the direction of airflow generated by the air blowing portion can be changed. 
     13. The work machine (e.g.,  1 A,  1 B,  1 C) of the above-described embodiment, in which 
     the air blowing portion (e.g.,  80 C) ejects air so as to levitate the main body portion to generate an airflow. 
     According to this embodiment, scattered objects can be efficiently moved to the target position using a drone. 
     The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.