Patent Publication Number: US-2022219949-A1

Title: Remote operation terminal and mobile crane provided with remote operation terminal

Description:
TECHNICAL FIELD 
     The present invention relates to a remote operation terminal and a mobile crane provided with the remote operation terminal. 
     BACKGROUND ART 
     Conventionally, regarding a mobile crane, a mobile crane in which an. actuator of a crane device is remotely operated and a remote operation terminal that remotely operates the actuator of the crane device have been proposed. In the work using the remote operation terminal, the worker can perform the work while confirming the moving state of a load near the load or at the target position of the load away from the operation device of the crane device. 
     In such a mobile crane, the relative positional relationship between the crane device and the remote operation terminal changes according to the work situation. For this reason, the worker who operates the crane device with the remote operation terminal needs to operate the operation tool of the remote operation terminal while always considering the relative positional relationship with the work device. Hence, there is known a remote operation. terminal capable of operating a crane device in an easy and simple manner by matching the operation direction of an operation tool of a remote operation terminal with the moving direction of the crane device, regardless of the relative positional relationship between the crane device and the remote operation terminal. Patent Literature 1 discloses one example. 
     A remote operation device (remote operation terminal) described in Patent Literature 1 is provided with a signal transmission unit that transmits a laser beam or the like having high straightness as a reference signal. Additionally, a control device on. the crane (work device) side is provided with a reference signal receiving unit. The remote operation device is configured such that the reference coordinate system of an operation tool coincides with the transmission direction of the reference signal. The crane side control device specifies the direction of The remote operation device by receiving the reference signal from the remote operation device with the reception unit, and matches the coordinate system of the crane with the coordinate system of the remote operation device. As a result, since the operating direction of the operating tool of the remote operation device and the moving direction of the crane coincide with each other, operation of the crane by the remote operation device can be performed in an easy and simple manner regardless of the relative positional relationship between the crane and the remote operation device. 
     However, the mobile crane described in Patent Literature 1 receives the reference signal with the reception unit to specify the relative direction of the remote operation device with respect to the working machine, and matches the reference coordinate system of the operation tool and the coordinate system of the working machine. For this reason, in a site where the crane cannot be visually recognized from the remote operation device, a site where there are many obstacles, or the like, the reception unit cannot receive the reference signal, and the coordinate system of the mobile crane cannot be matched with the coordinate system of the remote operation device in some cases. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2010-228905 A 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     An object of the present invention is to provide a remote operation terminal and a mobile crane including the remote operation terminal capable of preventing as erroneous operation at the time of remote operation of the mobile crane and performing the remote operation of the mobile crane in an easy and simple manner. 
     Solutions to Problems 
     The problem to be solved. by the present invention is as described above, and means for solving the problem will be described below. 
     That is, a first aspect of the present invention is 
     a remote operation terminal of a mobile crane including a position detection. unit that detects a current position of a tip of a boom, the remote operation terminal including: 
     a three-dimensional information acquisition unit that acquires three-dimensional information of each of the mobile crane and a planimetric feature within a movable range of the mobile crane; 
     a display unit that displays, in a virtual space, a three-dimensional image of each of the mobile crane and the planimetric feature within the movable range of the mobile crane; 
     a crane operation unit that receives a crane operation done by an operator and remotely operates the mobile crane so as to correspond to the crane operation; 
     an image operation unit that receives an image display changing operation done by the operator and controls a viewpoint position and a viewpoint direction in the three-dimensional image displayed on the display unit so as to correspond to the image display changing operation; and 
     a control unit that is configured to be communicable with a control device of the mobile crane and controls each unit of the remote operation terminal, in which 
     the control unit 
     acquires attitude information. of the mobile crane, movable range information of the mobile crane, and current position information of the tip of the boom from the control device of the mobile crane, 
     generates the three-dimensional image of the current mobile crane and the three-dimensional image of the planimetric feature within the movable range of the current mobile crane, on the basis of the information acquired from the control device of the mobile crane and the three-dimensional information acquired by the three-dimensional information acquisition unit, 
     displays the generated three-dimensional image in the virtual space of the display unit at the viewpoint position and the viewpoint direction input to the image operation unit, and 
     when the crane operation is input to the crane operation unit, associates a coordinate system of a horizontal plane of the three-dimensional image displayed on the display unit and an operation direction of the crane operation on the basis of the viewpoint position and the viewpoint direction, and generates a control signal for remotely operating the mobile crane so that the tip of the boom displayed on the display unit moves horizontally toward the operation direction of the crane operation. 
     According to a second aspect of the present invention, 
     in the above remote operation terminal, 
     the crane operation unit is configured to be capable of operating the three-dimensional image of the mobile crane displayed on the display unit, and 
     the control unit generates a control signal for remotely operating the mobile crane on the basis of operation information of the three-dimensional image by the crane operation unit. 
     According to a third aspect of the present invention, 
     in the above remote operation terminal, 
     the control unit acquires an image captured by a suspended load camera included in the mobile crane, and causes the display unit to display the acquired image together with the three-dimensional image. 
     A fourth aspect of the present invention is 
     a remote operation terminal of a mobile crane including a position detection unit that detects a current position of a tip of a boom, the remote operation terminal including: 
     an aerial camera that images the mobile crane and a planimetric feature within a movable range of the mobile crane; 
     an imaging information acquisition unit that acquires an image captured by the aerial camera, and position coordinates and a capturing direction of the aerial camera; 
     a display unit that displays the image; 
     a crane operation unit that receives a crane operation. done by an operator and remotely operates the mobile crane so as to correspond to the crane operation; and 
     a control unit that is configured to be communicable with a control device of the mobile crane and controls each unit of the remote operation terminal, in which 
     the control unit 
     acquires attitude information of the mobile crane and current position information of the tip of the boom of the mobile crane from the control device of the mobile crane, 
     displays the image acquired by the imaging information acquisition unit on the display unit, and 
     when the crane operation is input to the crane operation unit, associates a coordinate system of a horizontal plane of the image displayed on the display unit and an operation direction of the crane operation on the basis of the position coordinates and the imaging direction of the aerial camera, and generates a control signal for remotely operating the mobile crane so that the tip of the boom displayed on the display unit moves horizontally toward the operation direction of the crane operation. 
     A fifth aspect of the present invention is 
     the above remote operation terminal further including 
     an unmanned aerial vehicle having the aerial camera, and an aerial vehicle operation unit that operates the unmanned aerial vehicle, in which 
     the imaging information acquisition unit acquires position coordinates of the unmanned aerial vehicle and a direction of the aerial camera as position coordinates and an imaging direction of the aerial camera, and 
     the display unit displays the image captured by the aerial camera of the unmanned aerial vehicle operated by the aerial vehicle operation unit. 
     A sixth aspect of the present invention is 
     a mobile crane including the above remote operation. terminal, is which 
     a boom is operated on the basis of the control signal received from the remote operation terminal. 
     Effects of the Invention 
     The present invention has the following effects. 
     In the first and sixth aspects of the present invention, the remote operation terminal generates the control signal so that the tip of the boom in the three-dimensional image of the mobile crane in the virtual space displayed in an arbitrary direction from an arbitrary viewpoint moves in the operation direction of the crane operation unit in the display state. Hence, the remote operation of the mobile crane is intuitively performed without being conscious of the positional relationship of the viewpoint with respect to the mobile crane. As a result, an erroneous operation at the time of remote operation of the mobile crane can be prevented, and the remote operation of the mobile crane can be performed in an easy and simple mariner. 
     In the second aspect of the present invention, since the control signal of the mobile crane is generated on the basis of the movement of the mobile crane using the three-dimensional image in the virtual space, the mobile crane is operated in consideration of the surrounding situation and the operation condition. As a result, an erroneous operation at the time of remote operation of the mobile crane can be prevented, and the remote operation of the mobile crane can be performed in an easy and simple manner. 
     In the third aspect of the present invention, information such as a planimetric feature that is not reproduced in a three-dimensional image in the virtual space is displayed. As a result, an. erroneous operation at the time of remote operation of the mobile crane can be prevented, and the remote operation of the mobile crane can be performed in an easy and simple manner. 
     In the fourth aspect of the present invention, the operation direction reference of the remote operation terminal is set so that the tip of the boom of the mobile crane, which is imaged in an arbitrary imaging direction from arbitrary camera coordinates, moves in the operation direction of the crane operation unit in the display state. Hence, the remote operation of the mobile crane can be performed intuitively without being conscious of the positional relationship of the viewpoint with respect to the mobile crane. As a result, an erroneous operation at the time of remote operation of the mobile crane can be prevented, and the remote operation of the mobile crane can be performed an easy and simple manner. 
     In the fifth and sixth aspects of the present invention, the remote operation terminal generates the control signal so that the tip of the boom of the mobile crane imaged in an arbitrary imaging direction from arbitrary camera coordinates moves in the operation direction of the crane operation unit in the display state. Hence, the remote operation of the mobile crane can be performed intuitively without being conscious of the positional relationship of the camera coordinates with respect to the mobile crane. As a result, an erroneous operation at the time of remote operation of the mobile crane can be prevented, and the remote operation of the mobile crane can be performed in an easy and simple manner. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view illustrating an overall configuration of a crane. 
         FIG. 2  is a block diagram illustrating a control configuration of a crane. 
         FIG. 3  is a plan view illustrating a schematic configuration of a first embodiment of a remote operation terminal. 
         FIG. 4  is a block diagram illustrating a control configuration. of the remote operation terminal. 
         FIGS. 5(A) and 5(B)  illustrate the first embodiment of the remote operation terminal.  FIG. 5(A)  illustrates a state in which a three-dimensional image viewed from the side of the crane is displayed on the remote operation terminal, and  FIG. 5(B)  illustrates a state in which a three-dimensional image viewed from the upper front side of the crane is displayed on the remote operation terminal. 
         FIGS. 6(A) and 6(B)  illustrate the first embodiment of the remote operation terminal.  FIG. 6(A)  is an enlarged view of a three-dimensional image of the crane displayed on the remote operation terminal, and  FIG. 6(B)  illustrates a state in which a suspended load moving operation tool of the remote operation terminal is operated. 
         FIG. 7  is a partially enlarged view illustrating the display device when the suspended load moving operation tool is operated in a state where the three-dimensional images of the crane and planimetric features are displayed on the remote operation terminal. 
         FIG. 8  is a plan view illustrating the crane controlled by the remote operation terminal operated in  FIG. 7 . 
         FIG. 9  is a plan view illustrating a schematic configuration of a second embodiment of the remote operation terminal. 
         FIGS. 10(A) and 10(B)  illustrate the second embodiment of the remote operation terminal.  FIG. 10(A)  illustrates an unmanned aerial vehicle controlled by the remote operation terminal, and  FIG. 10(B)  illustrates a control image captured by the unmanned aerial vehicle. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a crane  1  which is a mobile crane according to a first embodiment of the present invention will be described with reference to  FIGS. 1 and 2 . Note that while a rough terrain crane will be described in the present embodiment, the crane may be an all-terrain crane, a truck crane, a truck loader crane, or the like. 
     As illustrated in  FIG. 1 , the crane  1  is a mobile crane that can be moved to an unspecified place. The crane  1  includes a vehicle  2 , a crane device  6  as a work device, a control device  31 , and a remote operation terminal  32  (see  FIG. 2 ) capable of remotely operating the crane device  6 . 
     The vehicle  2  is a mobile body that transports the crane device  6 . The vehicle  2  has a plurality of wheels  3  and travels using an engine  4  as a power source. The vehicle  2  is provided with an outrigger  5 . The outrigger  5  includes an overhanging beam that can be extended by hydraulic pressure on both sides in the width direction of the vehicle  2 , and a hydraulic jack cylinder that can be extended in a direction perpendicular to the ground. The vehicle  2  can expand the workable range of the crane  1  by extending the outrigger  5  in the width direction of the vehicle  2  and grounding the jack cylinder. 
     The crane device  6  is a device that lifts a load W with a wire rope. The crane device  6  includes a slewing base  7 , a boom  9 , a jib  9   a,  a main hook block  10 , a sub hook block  11 , a hydraulic derricking cylinder  12 , a main winch  13 , a main wire rope  14 , a sub winch  15 , a sub wire rope  16 , a cabin  17 , and the like. 
     The slewing base  7  is a device that slews the crane device  6 . The slewing base  7  is rotatable about the center of an annular bearing. The slewing base  7  is provided with a hydraulic slewing motor  8  that is an actuator. The slewing base  7  is slewable in one and the other direction by the hydraulic stewing motor  8 . 
     The hydraulic slewing motor  8 , which is an actuator, is rotationally operated by a slewing valve  23  (see  FIG. 2 ), which is an electromagnetic proportional switching valve. The slewing valve  23  can control the flow rate of hydraulic oil supplied to the hydraulic stewing motor  8  to an arbitrary flow rate. The slewing base  7  is provided with a slewing sensor  27  (see  FIG. 2 ) that detects a slewing position (angle) and a slewing speed of the stewing base  7 . 
     The boom  9  is a beam member that supports the wire rope in a state where the wire rope can lift the load W. The base end of a base boom member of the boom  9  is swing ably provided substantially at the center of the stewing base  7 . The boom  9  is capable of expanding and contracting in the axial direction by moving each boom member with a hydraulic expansion/contraction cylinder (not illustrated) which is an actuator. Additionally, the boom  9  is provided with the jib  9   a.    
     The hydraulic expansion/contraction cylinder (not illustrated) which is an actuator is expanded and contracted by an expansion/contraction valve  24  (see  FIG. 2 ) which is an electromagnetic proportional switching valve. The boom  9  is provided with an expansion/contraction sensor  28  that detects the length of the boom  9 , a weight sensor that detects the weight of the load W, and the like. 
     A suspended load camera  9   b  (see  FIG. 2 ) is an imaging device that images the load W and planimetric features around the load W. The suspended load camera  9   b  is provided in a tip part of the boom  9 . The suspended load camera  9   b  is capable of imaging the load W and planimetric features and topography around the crane  1  from vertically above the load W. 
     The main hook block  10  and the sub hook block  11  are members for suspending the load W. The main hook block  10  is provided with a plurality of hook sheaves around which the main wire rope  14  is wound, and a main hook  10   a  for suspending the load W. The sub hook block  11  is provided with a sub hook  11   a  for suspending the load W. 
     The hydraulic derricking cylinder  12  is an actuator that raises and lowers the boom  9  and holds the attitude of the boom  9 . The hydraulic derricking cylinder  12  is operated to expand and contract by a derricking valve  25  (see  FIG. 2 ) which is an electromagnetic proportional switching valve. The boom  9  is provided with a derricking sensor  29  (see  FIG. 2 ) that detects a derricking angle of the boom  9 . 
     The main winch  13  and the sub winch  15  spool (wind up) and feed (wind out) the main wire rope  14  and the sub wire rope  16 . The main winch  13  is configured such that a main drum around which the main wire rope  14  is wound is rotated by a main hydraulic motor (not illustrated) as an actuator, and the sub winch  15  is configured such that a sub drum around which the sub wire rope  16  is wound is rotated by a sub hydraulic motor (not illustrated) as an actuator. 
     The main hydraulic motor is rotationally operated by a main valve  26   m  (see  FIG. 2 ) which is an electromagnetic proportional switching valve. By controlling the main hydraulic motor with the main valve  26   m,  the main winch  13  can be operated at an arbitrary spooling and feeding speed. Similarly, by controlling the sub hydraulic motor with a sub valve  26   s  (see  FIG. 2 ), which is an electromagnetic proportional switching valve, the sub winch  15  can be operated at an arbitrary spooling and feeding speed. 
     The cabin  17  is mounted on the slewing base  7 . An unillustrated cockpit is provided. The cockpit is provided with an operation tool for operating traveling of the vehicle  2 , a slewing operation tool  18  for operating the crane device  6 , a derricking operation tool  19 , an expansion/contraction operation tool  20 , a main drum operation tool  21   m,  a sub drum operation tool  21   s,  and the like (see  FIG. 2 ). 
     A communication device  22  (see  FIG. 2 ) is a device that receives a control signal from the remote operation terminal  32  through a wide-area information. communication network or the like, and transmits control information and. the like from the crane device  6  through the wide-area information communication network or the like. The communication device  22  is provided in the cabin  17 . The communication device  22  is configured to transfer a control signal or the like to the control device  31  of the crane  1 , upon receipt of the control signal or the like from the remote operation terminal  32 . Additionally, the communication. device  22  is configured to transfer control information from the control device  31  and a suspended load image i 1  from the suspended load camera  9   h  to the remote operation terminal  32 . 
     The GNSS receiver  30  (see  FIG. 2 ), which is a position detection unit, is a receiver included in a global navigation satellite system, and is a device that receives a ranging electric wave from a satellite and detects latitude, longitude, and altitude, which are position coordinates of the receiver. The GNSS receiver  30  is provided at the tip of the boom  9  and in the cabin  17  (hereinafter, GNSS receivers provided at tip of boom  9  and in cabin  17  are collectively referred to as “GNSS receiver  30 ”). That is, the crane  1  can acquire position coordinates of the tip of the boom  9  and position coordinates of the cabin  17  with the GNSS receiver  30 . Additionally, the crane  1  can detect the arrangement of the boom  9  with respect to the tip (position of load W) of the boom  9  with the GNSS receiver  30 . Note that while the crane  1  detects the tip position of the boom  9  using the GNSS receiver  30  in the following embodiment, the crane  1  may detect the tip position of the boom  9  using known position detection means such as a fired point camera or near field wireless communication. 
     As illustrated in  FIG. 2 , the control device  31  is a device that controls an actuator of the crane I through each operation. valve. The control device  31  is provided in the cabin  17 . Substantially, the control device  31  may be configured such that a CPU, a ROM, a RAM, an HDD, and the like are connected by a bus, or may be configured of a one-chip LSI and the like. The control device  31  stores various programs and data in order to control the operation of each actuator, switching valve, sensor, and the like. 
     The control device  31  is connected to the suspended load camera  9   b,  the slowing operation tool  18 , the derricking operation tool  19 , the expansion/contraction operation tool  20 , the main drum operation tool  21   m,  and the sub drum operation tool  21   s,  can acquire the suspended load image i 1  of the suspended load camera  9   h,  and can acquire the operation amount of each of the stewing operation tool  18 , the derricking operation tool  19 , the main drum operation tool  21   m,  and the sub drum operation tool  21   s.    
     The control device  31  is connected to the communication device  22 , can acquire a control signal from the remote operation terminal  32 , and can transmit control information from the crane device  6 , the suspended load image i 1  from the suspended load camera  9   b,  and the like. 
     The control device  31  is connected to the slewing valve  23 , the expansion/contraction valve  24 , the derricking valve  25 , the main valve  26   m,  and the sub valve  26   s,  and can transmit a control signal to the slewing valve  23 , the derricking valve  25 , the main valve  26   m,  and the sub valve  26   s.    
     The control device  31  is connected to the slewing sensor  27 , the expansion/contraction sensor  28 , and the derricking sensor  29 , and can acquire attitude information such as the slewing position of the slewing base  7 , the boom length, and the derricking angle, and the weight of the load W. 
     The control device  31  is connected to the GNSS receiver  30 , and can acquire position coordinates of the tip of the boom  9  and position coordinates of the cabin  17 . Additionally, the control device  31  can calculate the arrangement of the boom  9  with respect to the tip (load W) of the boom  9  from the acquired position coordinates of the tip of the boom  9  and position coordinates of the cabin  17 . 
     The control device  31  generates a control signal corresponding to each operation tool on the basis of the operation amount of the slewing operation tool  18 , the derricking operation tool  19 , the main drum operation tool  21   m,  and the sub drum operation tool  21   s.    
     The crane  1  configured as described above can move the crane device  6  to an arbitrary position by causing the vehicle  2  to travel. Additionally, the crane  1  can expand the lifting range and the work radius of the crane device  6  by causing the boom  9  to stand at an arbitrary derricking angle by operating the hydraulic derricking cylinder  12  with the derricking operation tool  19  and extending the boom  9  to an arbitrary boom length by operating the expansion/contraction operation tool  20 . Additionally, the crane  1  can lift the load W by the sub drum operation tool  21   s  or the like, and can convey the load W by slewing the slewing base  7  by operating the slewing operation tool  18 . 
     Next, the remote operation terminal  32  that remotely operates the crane  1  will be described with reference to  FIGS. 3 to 5 (B). 
     As illustrated in  FIG. 3 , the remote operation terminal  32  is a device used for remotely operating the crane  1 . The remote operation terminal  32  includes a housing  33 , a viewpoint changing operation tool  34  which is an image operation unit provided on the operation surface of the housing  33 , a suspended load moving operation tool  35  which is a crane operation unit provided on the operation surface of the housing  33 , a terminal-side stewing operation tool  36 , a terminal-side expansion/contraction operation tool  37 , a terminal-side main drum operation tool  38   m,  a terminal-side sub drum operation tool  38   s,  a terminal-side derricking operation tool  39 , a display device  40  which is a display unit, a terminal-side communication device  41 , a terminal-side control device  43  (see  FIG. 4 ), and the like. The remote operation terminal  32  transmits a control signal of an operation valve of each actuator for moving the load W by operating the suspended load moving operation tool  35  or various operation tools to the crane device  6  through a wide area information communication network (the Internet or the like). 
     The housing  33  is a main component of the remote operation terminal  32 . The housing  33  is formed in a size that can be held by the operator&#39;s hand. The housing  33  is provided with the viewpoint changing operation tool  34 , the suspended load moving operation tool  35 , the terminal-side slewing operation tool  36 , the terminal-side expansion/contraction operation tool  37 , the terminal-side main drum operation tool  38   m,  the terminal-side sub drum operation tool  38   s,  the terminal-side derricking operation tool  39 , the display device  40 , and the terminal-side communication device  41  (see  FIGS. 2 and 4 ) on the operation surface. 
     The viewpoint changing operation tool  34  is an operation tool that receives input of an instruction to change the position of the viewpoint and the direction of the viewpoint of a three-dimensional image G displayed on the display device  40 . The viewpoint changing operation tool  34  includes a rotatable operation stick protruding from the operation surface of the housing  33 , and a sensor (not illustrated) that detects a rotation direction and rotation amount, and a tilt direction and tilt amount of the operation stick. With art operation of the operation stick, the viewpoint changing operation tool  34  transmits, to the terminal-side control device  43 , a signal regarding the position of the viewpoint and the direction of the viewpoint of the three-dimensional image G in the virtual space displayed on the display device  40 . That is, with an operation of the operation stick, the viewpoint changing operation tool  34  transmits, to the terminal-side control device  43 , an operation signal regarding the displacement amount of the three-dimensional image G in the virtual space displayed on the display device  40 . 
     The suspended load moving operation tool  35 , which is a first operation unit, is an operation tool that receives input of an instruction to move the load W at an arbitrary speed in an arbitrary direction on an arbitrary horizontal plane. The suspended load moving operation tool  35  includes an operation stick standing substantially vertically from the operation surface of the housing  33  and a sensor (not illustrated) that detects a tilt direction and a tilt amount of the operation stick. The suspended load moving operation tool  35  is configured such that the operation stick can be tilted in an arbitrary direction. The suspended load moving operation tool  35  is configured to transmit, to the terminal-side control device  43 , a signal regarding the angle and the tilt amount between the upward direction of the remote operation terminal  32  and the tilt direction of the operation stick detected by the sensor. The remote operation terminal  32  displays, as indicators of the tilting operation of the suspended load moving operation tool  35 , an arrow Aa indicating an upward direction at the time of facing the operation surface of the housing  33 , an arrow Ab indicating a rightward direction at the time of facing the operation surface, an arrow Ac indicating a downward direction at the time of facing the operation surface, and an arrow Ad indicating a leftward direction at the time of facing the operation surface. 
     The terminal-side slewing operation tool  36  is an operation tool that receives input of an instruction to slew the crane device  6  at an arbitrary moving speed in an arbitrary moving direction. The terminal-side slewing operation tool  36  includes an operation stick standing substantially vertically from the operation surface of the housing  33  and a sensor (not illustrated) that detects a tilt direction and a tilt amount of the operation stick. 
     The terminal-side expansion/contraction operation tool  37  is an operation tool that receives input of an instruction to expand and contract the boom  9  at an arbitrary speed. The terminal-side expansion/contraction operation tool  37  includes an operation stick standing from the operation surface of the housing  33  and a sensor (not illustrated) that detects a tilt direction and a tilt amount of the operation stick. 
     The terminal-side main drum operation tool  38   m  is an operation tool that receives input of an instruction to rotate the main winch  13  at an arbitrary speed in an arbitrary direction. The terminal-side main drum operation tool  38   m  includes an operation stick standing from the operation surface of the housing  33  and a sensor (not illustrated) that detects a tilt direction and a tilt amount of the operation stick. The terminal-side sub drum operation tool  38   s  is similarly configured. 
     The terminal-side derricking operation tool  39  is an operation tool that receives input of an instruction to raise or lower the boom  9  at an arbitrary speed. The terminal-side derricking operation tool  39  includes an operation stick standing from the operation surface of the housing  33  and a sensor (not illustrated) that detects a tilt direction and a tilt amount of the operation stick. 
     The display device  40  is a display device  40  that displays various information such as attitude information of the crane  1  and information of the load W. The display device  40  includes an image display device such as a liquid crystal screen. The display device  40  is provided on the operation surface of the housing  33 . The display device  40  displays the three-dimensional image G of the crane  1  arranged in the virtual space and the three-dimensional image G of a ground surface, planimetric features, and the like within the movable range of the crane  1  (hereinafter, both images are collectively referred to as “three-dimensional image G”). Note that while the display device  40  is provided in the remote operation terminal  32  in the present embodiment, the display device  40  may he a monitor separated from the remote operation terminal  32 . 
     Moreover, the display device  40  displays, as indicators of the tilting direction of the suspended load moving operation tool  35 , an arrow Aa in an upward direction at the time of facing the operation surface of the housing  33 , an arrow Ab indicating a rightward direction at the time of facing the operation surface, an arrow Ac indicating a downward direction at the time of facing the operation surface, and an arrow Ad indicating a leftward direction at the time of facing the operation surface. 
     As illustrated in  FIG. 4 , the terminal-side communication device  41  is a device that receives control information and the like of the crane device  6  through a wide-area information communication network or the like, and transmits control information and the like from the remote operation terminal  32  to the crane device  6 . The terminal-side communication device  41  is provided. inside the housing  33 . The terminal-side communication device  41  is configured to transmit the suspended load image i 1  (see  FIG. 7 ), the control signal, and the like to the terminal-side control device  43 , upon receipt of the suspended load image i 1 , a control signal, and the like from the crane device  6 . Additionally, the terminal-side communication device  41  is configured to transmit control information from the terminal-side control device  43 , from the wide-area information communication network or the like to the crane device  6  through the communion device  22  of the crane  1 . 
     The terminal-side control device  43  as a control unit is a device that controls the remote operation terminal  32 . The terminal-side control device  43  is provided inside the housing  33  of the remote operation terminal  32 . Substantially, the terminal-side control device  43  may be configured such that a CPU, a ROM, a PJM, an HDD, and the like are connected by a bus, or may be configured of a one-chip LSI and the like. The terminal-side control device  43  includes a three-dimensional information acquisition unit  42 . The terminal-side control device  43  stores various programs and data in order to control operations of the suspended load moving operation tool  35 , the viewpoint changing operation tool  34 , the terminal-side slewing operation tool  36 , the terminal-side expansion/contraction operation tool  37 , the terminal-side main drum operation tool  38   m,  the terminal-side sub drum operation tool  38   s,  the terminal-side derricking operation tool  39 , the display device  40 , the terminal-side communication device  41 , and the like. 
     The terminal-side control device  43  is connected to the suspended load moving operation tool  35 , the terminal-side stewing operation tool  36 , the terminal-side expansion/contraction operation tool  37 , the terminal-side main drum operation tool  38   m,  the terminal-side sub drum operation tool  38   s,  and the terminal-side derricking operation tool  39 , and can acquire an operation signal including a tilt direction and a tilt amount of the operation stick of each operation tool. Additionally, the terminal-side control device  43  is connected to the viewpoint changing operation tool  34 , and can acquire an operation signal including the rotation direction and rotation amount, and the tilt direction and tilt amount input to the viewpoint changing operation tool  34 . 
     The terminal-side control device  43  is connected to the terminal-side communication device  41 , and can transmit and receive various types of information to and from the control device  31  through the communication device  22  of the crane device  6  connected through the wide-area information communication network. Specifically, the terminal-side control device  43  can acquire, from the control device  31 , attitude information of the crane  1 , the suspended load image i 1  captured by the suspended load camera  9   b,  the movable range of the crane  1 , and the current position of the tip of the boom  9 . 
     The three-dimensional information acquisition unit  42  of the terminal-side control device  43  can acquire three-dimensional information of the crane  1  (e.g., information on three-dimensional shape of crane  1 ), three-dimensional information of a planimetric feature within a movable range of the crane  1  (e.g., information on three-dimensional shape of planimetric feature), and the like from the control device  31  of the crane  1  or a building information modeling (BIM) such as a management server (not illustrated) through the wide-area information communication network. 
     The terminal-side control device  43  can generate a control signal of a corresponding one of the slewing valve  23 , the expansion/contraction valve  24 , the derricking valve  25 , the main valve  26   m,  and the sub valve  26   s  from the operation signal of each operation stick acquired from each sensor of the terminal-side slewing operation tool  36 , the terminal-side expansion/contraction operation tool  37 , the terminal-side main drum operation tool  38   m,  the terminal-side sub drum operation tool  38   s,  and the terminal-side derricking operation tool  39 . 
     The terminal-side control device  43  can generate the three-dimensional image G of the crane  1  in the attitude of the current crane  1  and planimetric features within the movable range of the current crane  1 , on the basis of the attitude information of the crane  1 , the movable range of the crane  1  and current position of the tip of the boom  9 , the three-dimensional information of the crane  1  and three-dimensional information of planimetric features within the movable range of the crane  1 , and the like acquired from the control device  31  of the crane  1 . 
     The terminal side control device  43  is connected to the display device  40 , and can cause, the display device  40  to display the three-dimensional image G of the crane  1  in the attitude of the current crane  1  and the planimetric features within the movable range of the current crane  1 , the suspended load image i 1  from the suspended load camera  9   b,  and various types of information acquired from the crane  1 . Additionally, the terminal-side control device  43  can display the three-dimensional image G displayed on the display device  40  as a three-dimensional image G from an arbitrary viewpoint position and viewpoint direction in synchronization with the rotation direction and rotation amount and the tilt direction and tilt amount input to the viewpoint changing operation tool  34 . 
     The terminal-side control device  43  generates a control signal of the crane  1  when the suspended load moving operation tool  35  is tilted, with reference to a display state which is a position and an orientation on a screen of the three-dimensional image S of the crane  1  in the virtual space displayed on the display device  40 . For example, when the suspended load moving operation tool  35  is tilted in the direction of the arrow Aa or the direction of the arrow Ac (hereinafter simply referred to as “vertical direction of remote operation terminal  32 ”), which is the vertical direction of the remote operation terminal  32 , the terminal-side control device  43  generates a control signal of the crane  1  in which the tip of the boom  9  is moved horizontally as well as in the vertical direction at the time of facing the operation surface of the housing  33  in the virtual space. Additionally, when the suspended load moving operation tool  35  is tilted in the direction of the arrow Ab or the direction of the arrow Ad (hereinafter simply referred to as “left-right direction of remote operation terminal  32 ”), which is the left-right direction at the time of facing the operation surface of the housing  33 , the terminal-side control device  43  generates a control signal of the crane  1  in which the tip of the boom  9  is moved horizontally and in the left-right direction at the time of facing the operation surface of the housing  33  in the virtual space. As described above, when the suspended load moving operation tool  35  is tilted in an arbitrary direction, the terminal-side control device  43  generates a control signal of the crane  1  in which the tip of the boom  9  is moved horizontally and in the tilting direction of the suspended load moving operation tool  35  in virtual space, in the display state of the three-dimensional image P of the crane  1  displayed in virtual space. 
     Moreover, the terminal-side control device  43  generates a control signal of the crane  1 , and. also moves the tip of the boom  9  in the three-dimensional image G of the crane  1  displayed on the display device  40  in the tilting direction of the suspended load moving operation tool  35 . That is, the remote operation terminal  32  can confirm the operating state of the crane  1 , in advance, by the movement of the three-dimensional image G of the crane  1  in the virtual space displayed on the display device  40 . When a transmission operation. is given or a predetermined condition (e.g., predetermined time elapses from generation of control signal) is satisfied for a generated control signal, the terminal-side control device  43  transmits the control signal to the control device  31  of the crane  1 . 
     As illustrated in  FIGS. 5  (A) and  5 (B), the terminal-side control device  43  (see  FIG. 4 ) displays, on the display screen, the three-dimensional image G rotated and moved on the basis of an operation signal related to the rotation direction and rotation amount and the tilt direction and tilt amount acquired from the rotated and tilted viewpoint changing operation tool  34 . In the present embodiment, a forward direction of the crane  1  is defined as an X-axis direction, a direction perpendicular to the forward direction of the crane  1  is defined as a Y direction, and the vertical direction of the crane  1 , which is a direction perpendicular to the ground surface in the virtual space, is defined as a Z direction. 
     As illustrated in  FIG. 5(A) , the terminal-side control device  43  causes the display device  40  to display the three-dimensional image G in the virtual space on the basis of attitude information of the crane  1 , the movable range of the crane  1 , the current position of the tip of the boom  9  acquired from the control device  31  of the crane  1 , and the three-dimensional information of the crane  1  and the three-dimensional information of planimetric features within the movable range of the crane  1 , and the like acquired from the BIM. In the present embodiment, the display device  40  displays the three-dimensional image G of the crane  1  in which the direction. of the line of sight is the direction along the Y-axis at the position of the viewpoint from the left side in the forward direction of the crane  1 . 
     As illustrated in  FIG. 5(B) , when the viewpoint changing operation tool  34  is rotated and tilted, the terminal-side control device  43  rotates and moves the three-dimensional image G of the crane  1  displayed on the display device  40  on the basis of the rotation direction and rotation amount and the tilt direction and tilt amount of the viewpoint changing operation tool  34 . When the viewpoint changing operation tool  34  is rotated counterclockwise and tilted downward with respect to the remote operation terminal  32 , the terminal-side control device  43  rotates the three-dimensional image G of the crane  1  displayed on the display device  40  in the state of  FIG. 5(A)  counterclockwise about the Z-axis, and displays the state of  FIG. 5(B)  rotated counterclockwise about the X-axis on the display device  40 . 
     As illustrated in  FIGS. 6(A) and 6(B) , the terminal-side control device  43  (see  FIG. 4 ) generates a control signal of the crane  1  on the basis of the operation signal related to the tilting direction and tilting amount acquired from the tilted suspended load moving operation tool  35 , and simultaneously moves the tip of the boom  9  in the three-dimensional image G of the crane  1  in the tilting direction of the suspended load moving operation tool  35 . When the suspended load moving operation tool  35  is tilted in the direction of the arrow Aa (see  FIG. 6(A) ), which is the upward direction of the remote operation terminal  32 , the terminal-side control device  43  moves the tip of the boom  9  in the three-dimensional image G of the crane  1  displayed on the display device  40  horizontally as well as in a direction perpendicular to the operation surface of the remote operation terminal  32  in the virtual space from the display state (see  FIG. 6(B) ). That is, the terminal-side control device  43  moves the tip of the boom  9  in the display state of the three-dimensional image G of the crane  1  in the upward direction of the remote operation terminal  32  which is the same direction as the tilting direction of the suspended load moving operation tool  35  on the screen of the display device  40  (see white arrow). In the crane  1  in the virtual space, the tip of the, boom  9  moves toward the −X-axis direction which is the backward direction as well as the Y-axis which is the left direction in the forward direction. 
     Hereinafter, control of the crane  1  by the remote operation terminal  32  will be described with reference to  FIGS. 7 and 8 . In the present embodiment, assume that the crane  1  is disposed at a position away to such an extent that the operator who operates the remote operation terminal  32  cannot visually recognize the crane  1 . Assume that the crane  1  and the remote operation terminal  32  are communicable through the wide-area information communication network. As a result, the crane  1  can be operated by the remote operation. terminal  32  regardless of whether it is inside or outside the country as long as the crane  1  can be connected to the wide-area information communication network. Additionally, also assume that the remote operation terminal  32  acquires attitude information of the crane  1 , the movable range of the crane  1 , and the current position of the tip of the boom  9  of the crane  1  from the control device  31  of the crane  1 . Moreover, assume that the remote operation terminal  32  acquires three-dimensional information of the crane  1  and three-dimensional information of planimetric features and the like of the work site from a BIM included in a server or the like (not illustrated). 
     As illustrated in  FIG. 7 , the display device  40  of the remote operation terminal  32  displays the three-dimensional image G of the crane  1  and planimetric features within a movable range of the crane  1 . The three-dimensional image P displayed on the display device  40  is rotated and moved in an arbitrary viewpoint position and viewpoint direction by the viewpoint changing operation tool  34 . 
     When the suspended load moving operation tool  35  is tilted in the direction of the arrow Aa (see arrow in  FIG. 6(A) ), which is the upward direction of the remote operation terminal  32 , the terminal-side control device  43  (see  FIG. 4 ) generates a control signal for moving the tip of the boom  9  horizontally as well as in a vertical direction at the time of facing the operation surface of the housing  33  in the virtual space in the display state of the three-dimensional image G of the crane  1  displayed on the display device  40 . At the same time, the terminal-side control device  43  moves the tip of the boom  9  in the three-dimensional image G of the crane  1  horizontally as well as in a vertical direction at the time of facing the operation surface of the housing  33  in the virtual space (see white arrow). When the transmission operation of the generated control signal is performed, the terminal-side control device  43  transmits the control signal to the control device  31  (see  FIG. 2 ) of the crane  1 . 
     When the terminal-side main drum operation tool  38   m  or the terminal-side sub drum operation tool  38   s  is operated in the vertical direction of the remote operation terminal  32 , the terminal-side control device  43  winds up or winds out the main wire rope  14  or the sub wire rope  16 . That is, regardless of the display state or the three-dimensional image G of the crane  1  displayed on the display device  10 , when the terminal-side main drum operation tool  38   m  or the terminal-side sub drum operation tool  38   s  is operated in the upward direction of the remote operation terminal  32 , the terminal-side control device  43  generates a control signal so that the load W moves in a direction away from the ground. Additionally, when the terminal-side main drum operation tool  38   m  or the terminal-side sub drum operation tool  38   s  is operated in the downward direction of the remote operation terminal  32 , the terminal-side control device  43  generates a control signal so that the load W moves in a direction approaching the ground. 
     As illustrated in  FIG. 8 , the control device  31  (see  FIG. 2 ) of the crane  1  acquires a control signal from the terminal-side control device  43  (see  FIG. 4 ) of the remote operation terminal  32  using a wide-area information communication network or the like. The control device  31  controls each valve of each actuator on the basis of the acquired control signal. The crane  1  moves the tip of the boom  9  so as to correspond to the movement of the tip of the boom  9  in the display state of the three-dimensional image G of the crane  1  of the display device  40  illustrated in  FIG. 7  (see white arrow). 
     With this configuration, the remote operation terminal  32  (see  FIG. 4 ) generates the control signal so that the tip of the boom  9  in the display state of the three-dimensional image G (see  FIG. 7 ) of the crane  1  in the virtual space displayed from an arbitrary viewpoint and line-of-sight direction moves in the tilting direction. of the suspended load moving operation tool  35  (i.e., operating direction of crane operation). Hence, the remote operation of the crane  1  is intuitively performed without being conscious of the positional relationship of the viewpoint with respect to the crane  1 . Additionally, since the control signal of the crane  1  is generated on the basis of the movement of the crane  1  using the three-dimensional image G in the virtual space, the crane  1  is operated consideration of the surrounding situation and operation conditions. As a result, an erroneous operation at the time of remote operation of the crane  1  can be prevented, and the remote operation of the crane  1  can be performed in an easy and simple manner. 
     Note that as illustrated in  FIG. 7 , the display device  40  of the remote operation terminal  32  may display the suspended load image i 1  captured by the suspended load camera  9   b  (see  FIG. 2 ) of the crane  1 . The terminal-side control device  43  causes the display device  40  to display the suspended load image i 1  acquired from the control device  31  of the crane  1  such that the suspended load image i 1  is rotated by a rotation angle around the Z-axis of the three-dimensional image G of the crane  1 . 
     With this configuration, information of a planimetric feature or the like that is not reproduced in the three-dimensional image G in the virtual space is displayed by the suspended load image i 1 . As a result, an erroneous operation at the time of remote operation of the mobile crane  1  can be prevented, and the remote operation of the mobile crane  1  can be performed in an easy and simple manner. 
     Next, a crane  1  according to the present invention and a remote operation terminal  32  as a second embodiment of the remote operation terminal of the crane  1  will be described with reference to  FIGS. 9, 10 (A), and  10 (B). Note that the crane  1  and the remote operation terminal  32  according to the following embodiment are applied in place of the crane  1  and the remote operation terminal  32  to the crane  1  and the remote operation terminal  32  illustrated in  FIGS. 1 to 8 , and the names, figure numbers, and reference numerals used in the description are used to indicate the same components. In the following embodiment, points similar to those of the previously described embodiment will not be specifically described, and differences will be mainly described. 
     As illustrated in  FIG. 9 , the remote operation terminal  32  is a device used for remotely operating the crane  1 . The remote operation terminal  32  includes a housing  33 , a camera position change operation tool  44  which is an aerial vehicle operation unit, a suspended load moving operation tool  35  of the housing  33 , a terminal-side slewing operation tool  36 , a terminal-side expansion/contraction operation tool  37 , a terminal-side main drum operation tool  38   m,  a terminal-side sub drum operation tool  38   s,  a terminal-side derricking operation tool  39 , a display device  40 , a terminal-side communication device  41 , an unmanned aerial vehicle  45 , an aerial camera  46 , a terminal-side control device  47 , and the like. 
     The camera position change operation tool  44  is an operation tool that receives input of an operation of the unmanned aerial vehicle  45  capturing an image displayed on the display device  40 . That is, the camera position change operation tool  44  is an operation tool that changes the position coordinates and the imaging direction of the aerial camera  46  by operating the unmanned aerial vehicle  45 . The camera position change operation tool  44  includes a rotatable operation stick protruding from an operation surface of the housing  33 , and a sensor (not illustrated) that detects a rotation direction and rotation amount, and a tilt direction and tilt amount of the operation stick. 
     With an operation of the operation stick, the camera position change operation tool  44  transmits, to the terminal-side control device  47 , a signal regarding the position coordinates of the unmanned aerial vehicle  45  holding the aerial camera  46  and the direction of the camera. That is, with an operation of the operation stick, the camera position change operation tool  44  transmits, to the terminal-side control device  47 , a signal regarding the camera coordinates and the displacement amount in the photographing direction of a control image i 2 , which is an image from the aerial camera  46  displayed on the display device  40 . 
     The display, device  40  is a display device  40  that displays various information such as attitude information of the crane  1  and information of the load W. The display device  40  includes an image display device such as a liquid crystal screen. The display device  40  is provided on the operation surface of the housing  33 . The display device  40  displays the control image i 2  of the crane  1  and the ground surface, the ground object, and the like within. the movable range of the crane  1  captured by the aerial camera  46 . 
     The terminal-side communication device  41  is a device that receives control information of a crane device  6 , the unmanned aerial vehicle  45 , and the aerial camera  46 , the control image i 2  from the aerial camera  46 , and the like through a wide-area information communication network or the like, and transmits the control information and the like from the remote operation terminal  32  to the crane device  6  and the unmanned aerial vehicle  45 . Upon receipt of a suspended load image i 1  from the crane device  6 , the control image i 2  from the aerial camera  46 , control signals of the crane device  6  and the unmanned aerial vehicle  45 , and the like, the terminal-side communication device  41  transmits the suspended load image i 1 , the control image i 2 , the control signals, and the like to the terminal-side control device  47 . Additionally, the terminal-side communication device  41  transmits control information from the terminal-side control device  47  to the crane device  6  or to the unmanned aerial vehicle  45  through the communication device  22  of the crane  1  from the wide-area information communication network or the like. 
     The unmanned aerial vehicle  45  is a moving device that transports the aerial camera  46 . The unmanned aerial vehicle  45  has a plurality of rotary blades  45   a  (see  FIG. 10(A) ). The unmanned aerial vehicle  45  can fly while maintaining an arbitrary attitude or stop flight (hover) by controlling the plurality of rotary blades  45   a.  The unmanned aerial vehicle  45  can move to an arbitrary position and stop by a control signal from the remote operation terminal  32 . The unmanned aerial vehicle  45  is provided with an aerial vehicle-side GNSS receiver  45   b  (see  FIG. 9 ) and the aerial camera  46 . The unmanned aerial vehicle  45  can acquire position coordinates of the unmanned aerial vehicle  45  with the aerial vehicle-side GNSS receiver  45   b.  The unmanned aerial vehicle  45  can image an object from camera coordinates which are position coordinates of the unmanned aerial vehicle  45  and an imaging direction by stop flight. 
     The terminal-side control device  47  as a control unit is a device that controls the remote operation terminal  32 . The terminal-side control device  47  includes an imaging information acquisition unit  48 . The terminal-side control device  47  stores various programs and data in order to control operations of the suspended load moving operation tool  35 , the terminal side slewing operation tool  36 , the terminal-side expansion/contraction operation tool  37 , the terminal-side main drum operation tool  38   m,  the terminal-side sub drum operation tool  38   s,  the terminal-side derricking operation tool  39 , the display device  40 , the terminal-side communication device  41 , the camera position change operation tool  44 , and the like. 
     The terminal-side control device  47  is connected to the terminal-side communication device  41 , and can transmit and receive various types of information to and from the unmanned aerial vehicle  45  connected through a wide-area information communication network or the like. Specifically, the terminal-side control device  47  can acquire the camera coordinates, the imaging direction, and the control image i 2  captured by the aerial camera  46  from the unmanned aerial vehicle  45 . 
     The terminal-side control device  47  is connected to the display device  40 , and can cause the display device  40  to display the control image  12  in which the aerial camera  46  captures the current crane  1  and surrounding planimetric features or the like from an arbitrary capturing direction at arbitrary camera coordinates. 
     The terminal-side control device  47  generates a control signal of the crane  1  when the suspended load moving operation tool  35  is tilted, with reference to a display state which is a position and an orientation on a screen of the control image i 2  of the crane  1  displayed on the display device  40 . Specifically, when the suspended load moving operation tool  35  is tilted in the vertical direction of the remote operation terminal  32 , the terminal-side control device  47  generates a control signal of the crane  1  in which the tip of the boom  9  moves horizontally as well as in a direction corresponding to the vertical direction at the time of facing the operation surface of the housing  33  from the display state of the control image i 2 . Additionally, when the suspended load moving operation tool  35  is tilted the left-right direction of the remote operation terminal  32 , the terminal-side control device  47  generates a control signal of the crane i in which the tip of the boom  9  moves horizontally as well as in a direction corresponding to the left-right direction at the time of facing the operation surface of the housing  33  from the display state of the control image i 2 . That is, the terminal-side control device  47  generates a control signal in which the tip of the boom  9  in the display state of the control image i 2  of the crane  1  moves in a direction corresponding to the same direction as the tilting direction of the suspended load moving operation tool  35  on the screen of the display device  40 . 
     As illustrated in  FIG. 10(A) , the unmanned aerial vehicle  45  performs stop flight at an arbitrary positron by a control signal from. the remote operation terminal  32 . The unmanned aerial vehicle  45  transmits the position coordinates and the attitude during the stop flight to the remote operation terminal  32  as camera coordinates and an imaging direction. At the same time, the unmanned aerial vehicle  45  transmits the control image i 2  captured by the aerial camera  46  to the remote operation terminal  32 . 
     As illustrated in  FIG. 10(B) , the control image i 2  captured by the aerial camera  46  is displayed on. the display device  40  of the remote operation terminal  32 . The control image i 2  displayed on the display device  40  is captured from an arbitrary capturing direction at arbitrary camera coordinates by the camera position change operation tool  44 . The terminal-side control device  47  of the remote operation terminal  32  generates a control signal for moving the tip of the boom  9  of the crane  1  in a direction corresponding to the tilting direction of the suspended load moving operation tool  35  on the screen of the display device  40 . 
     With this configuration, the terminal-side control device  47  of the remote operation terminal  32  generates the control signal so that the tip of the boom  9  of the crane  1  displayed on the display device  40  moves in the direction corresponding to the tilting direction of the suspended load moving operation tool  35  in the display state. Hence, the remote operation of the crane  1  is intuitively performed without being conscious of the positional relationship between the camera coordinates of the aerial camera  46 , which is the viewpoint for the crane  1 , and the imaging direction. As a result, an erroneous operation at the time of remote operation of the crane  1  can be prevented, and the remote operation of the crane  1  can be performed is an easy and simple manner. 
     In the present embodiment, the remote operation terminal  32  acquires the control image i 2  from the aerial camera  46  of one unmanned aerial vehicle  45 . However, the remote operation terminal  32  may acquire the control image i 2  from the aerial camera  46  of each of a plurality of unmanned aerial vehicles  45 . The remote operation terminal  32  can arbitrarily switch among a plurality of control images i 2  captured from different capturing directions at different camera coordinates and use the control images i 2  for controlling the crane  1 . With this configuration, it is not necessary to move the unmanned aerial vehicle  45  each time, so that the remote operation of the crane  1  can be performed in an easy and simple manner. Additionally, instead of the aerial camera  46  included in the unmanned aerial vehicle  45 , an image from a ground surface camera installed at an arbitrary position may be used. 
     The above-described embodiments are merely representative forms, and various modifications can be made without departing from the gist of one embodiment. It is a matter of course that the present invention can be implemented in various other forms. The scope of the present invention is indicated by the description of the claims, and further includes equivalents of the description of the claims and all modifications within the scope. 
     The entire disclosure of the specification, drawings, and abstract included in Japanese Patent Application No. 2019 096382 filed on May 22, 2019 is incorporated herein by reference. 
     REFERENCE SIGNS LIST 
     
         
           1  crane 
           6  crane device 
           9  boom 
           30  GNSS receiver 
           31  control device 
           32  remote operation terminal 
           34  viewpoint changing operation tool 
           35  suspended load moving operation tool 
           40  display device 
           41  terminal-side communication device 
           43  terminal-side control device 
           44  camera position change operation tool 
           45  unmanned aerial vehicle 
           46  aerial camera 
           47  terminal-side control device