Patent Publication Number: US-2020278673-A1

Title: Information processing apparatus and flight control system

Description:
TECHNICAL FIELD 
     The present invention relates to providing piloting assistance for a pilot of a flight vehicle. 
     BACKGROUND ART 
     As one example of technology for controlling a flight vehicle, JP 2014-104797A discloses a system in which light emitted from a light emitter provided in a flight vehicle is tracked by a camera provided on a moving mechanism in order to capture images of the flight state of the flight vehicle, and the captured images are displayed at a remote location. 
     SUMMARY OF INVENTION 
     Technical Problem 
     Various types of services that employ flight vehicles called drones have become prevalent in recent years. Under such circumstances, consideration is being given to systems for remotely providing piloting assistance to a pilot who is inexperienced with the piloting of a flight vehicle. In view of this, an object of the present invention is to provide a system that can provide piloting assistance to a pilot of a flight vehicle from a remote location. 
     Solution to Problem 
     In order to solve the foregoing problems, the present invention provides an information processing apparatus including: a first communication unit configured to perform communication with a first piloting terminal that is for wirelessly piloting a flight vehicle; a second communication unit configured to perform communication with a second piloting terminal that is for piloting the flight vehicle via a network; a determination unit configured to determine whether the first piloting terminal or the second piloting terminal is to pilot the flight vehicle based on information that the first communication unit receives from the first piloting terminal or information that the second communication unit receives from the second piloting terminal; and a remote control unit configured to, in a case where it is determined that the second piloting terminal is to pilot the flight vehicle, transfer an instruction for the flight vehicle that is received from the second piloting terminal to the flight vehicle. 
     An aspect is possible in which in a case where it is determined that the second piloting terminal is to pilot the flight vehicle, the remote control unit uses the first communication unit to notify the first piloting terminal that the second piloting terminal is to pilot the flight vehicle, and if permission is received in response to the notification, the remote control unit transfers an instruction for the flight vehicle that is received from the second piloting terminal to the flight vehicle. 
     An aspect is possible in which the determination unit specifies a piloting experience level with respect to the first piloting terminal based on information that the first communication unit receives from the first piloting terminal or information that the second communication unit receives from the second piloting terminal, and makes the determination based on the experience level. 
     An aspect is possible in which the determination unit specifies a flight environment of the flight vehicle based on information that the first communication unit receives from the first piloting terminal, and makes the determination based on the flight environment. 
     An aspect is possible in which the determination unit specifies a state of the flight vehicle based on information that the first communication unit receives from the first piloting terminal, and makes the determination based on the state. 
     An aspect is possible in which the first communication unit and the second communication unit relay audio communication between the first piloting terminal and the second piloting terminal, and information that the first communication unit receives from the first piloting terminal is output by audio with use of the second communication unit. 
     An aspect is possible in which in a case where there are a plurality of sets of the first piloting terminal and the second piloting terminal, the determination unit makes the determination for each set of the first piloting terminal and the second piloting terminal, and for each set of the first piloting terminal and the second piloting terminal, in a case where it is determined that the second piloting terminal is to pilot the flight vehicle, the remote control unit transfers an instruction for the flight vehicle that is received from the second piloting terminal to the flight vehicle. 
     The present invention also provides a flight control system including: a first piloting terminal for wirelessly piloting a flight vehicle; a second piloting terminal for piloting the flight vehicle via a network; a first communication unit configured to perform communication with the first piloting terminal; a second communication unit configured to perform communication with the second piloting terminal; a determination unit configured to determine whether the first piloting terminal or the second piloting terminal is to pilot the flight vehicle based on information that the first communication unit receives from the first piloting terminal or information that the second communication unit receives from the second piloting terminal; and a remote control unit configured to, in a case where it is determined that the second piloting terminal is to pilot the flight vehicle, transfer an instruction for the flight vehicle that is received from the second piloting terminal to the flight vehicle. 
     According to the present invention, it is possible to provide piloting assistance to a pilot of a flight vehicle from a remote location. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram showing an example of the configuration of flight control system. 
         FIG. 2  is a diagram showing an example of the appearance of flight vehicle. 
         FIG. 3  is a diagram showing a hardware configuration of flight vehicle. 
         FIG. 4  is a diagram showing a hardware configuration of first piloting terminal. 
         FIG. 5  is a diagram showing a hardware configuration of second piloting terminal. 
         FIG. 6  is a diagram showing a hardware configuration of server apparatus. 
         FIG. 7  is a diagram showing an example of the functional configuration of server apparatus. 
         FIG. 8  is a diagram showing an example of a display image determination table. 
         FIG. 9  is a diagram showing an example of a main pilot determination table. 
         FIG. 10  is a sequence chart showing an example of operations of flight control system. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Configuration 
       FIG. 1  is a diagram showing an example of the configuration of flight control system  1 . Flight control system  1  is a system for controlling the flight of flight vehicle  10 . Flight control system  1  includes flight vehicle  10 , server apparatus  20 , first piloting terminal  30 , image capturing apparatus  40 , second piloting terminal  50 , and network  60 . Flight vehicle  10  is a flight-capable apparatus called a drone for example, and includes an image capturing function for capturing a moving image of its surroundings. The images captured with this image capturing function are images from the viewpoint of flight vehicle  10 , and will hereinafter be called flight vehicle viewpoint images. 
     First piloting terminal  30  is a terminal for allowing a pilot to pilot flight vehicle  10  while viewing flight vehicle  10 . First piloting terminal  30  is wirelessly connected to flight vehicle  10  and gives operation instructions thereto by transmitting wireless signals that correspond to operations performed by the pilot to the flight vehicle  10 . 
     Image capturing apparatus  40  is a camera for example, and captures a moving image of the flight of flight vehicle  10 . This image capturing apparatus  40  includes pan and tilt functions, and by using image recognition technology to analyze the captured images and recognize flight vehicle  10  in the captured images, and then controlling the pan and tilt functions, image capturing apparatus  40  can change the shooting direction during image capturing so as to follow the recognized flight vehicle  10 . This image capturing apparatus  40  may be a fixed image capturing apparatus that is disposed on the ground below the airspace of flight vehicle  10 , or may be a portable image capturing apparatus that can be carried by a person. In the present embodiment, image capturing apparatus  40  is portable, and is placed near the pilot and captures images of the space including flight vehicle  10 . The images captured by image capturing apparatus  40  include substantially the same field of view as the case of viewing the flight of flight vehicle  10  from the viewpoint of the pilot, and will hereinafter be called pilot viewpoint images. 
     Second piloting terminal  50  is a terminal for allowing a piloting assister to remotely assist the piloting of the flight vehicle by the pilot. Second piloting terminal  50  includes a display function and can display the aforementioned flight vehicle viewpoint images or pilot viewpoint images. The piloting assister assists the piloting performed by the pilot, by operating second piloting terminal  50  while viewing such images. Here, with respect to a piloting experience level that indicates the amount of piloting experience, it is presumed that the piloting assister who is operating second piloting terminal  50  has a higher piloting experience level than the pilot who is operating first piloting terminal  30 . 
     Server apparatus  20  is an information processing apparatus that functions as a control platform for controlling the flight of flight vehicle  10 . Server apparatus  20  performs flight control by determining whether the piloting of flight vehicle  10  is to be performed by first piloting terminal  30  operated by the pilot or second piloting terminal  50  operated by the piloting assister, and in a case of determining that the piloting of flight vehicle  10  is to be performed by second piloting terminal  50 , then transferring commands for flight vehicle  10  received from second piloting terminal  50  to flight vehicle  10 . 
     Also, server apparatus  20  causes either the flight vehicle viewpoint images captured through the image capturing function of flight vehicle  10  or the pilot viewpoint images of the flight of flight vehicle  10  captured by image capturing apparatus  40  to be displayed with priority on second piloting terminal  50 . Here, “displayed with priority” means that the one type of captured images that are to be displayed with priority will be displayed on second piloting terminal  50  in a manner of being more visible or comprehensible to the user than the other type of captured images, and examples of this include an aspect for displaying the priority captured images and not displaying the other captured images, an aspect for displaying the priority captured images at a larger size than the other captured images, an aspect for displaying the priority captured images at an earlier time than the other captured images, and an aspect for displaying the priority captured images in a more visually emphasized manner than the other captured images. 
     Server apparatus  20 , first piloting terminal  30 , image capturing apparatus  40 , and second piloting terminal  50  are connected wirelessly or by wire in network  60  so as to be able to communicate with each other. In order to realize low-latency data transfer, it is desirable that network  60  is a closed network. 
       FIG. 2  is a diagram showing an example of the appearance of flight vehicle  10 . Flight vehicle  10  is also called a drone for example, and includes propellers  101 , driving apparatuses  102 , and battery  103 . 
     Propellers  101  rotate around shafts. Flight vehicle  10  flies due to rotation of propellers  101 . Driving apparatuses  102  give motive power to propellers  101  to cause rotation thereof. Driving apparatuses  102  each include a motor and a transmission mechanism for transmitting motive power from the motor to the propeller  101 , for example. Battery  103  supplies electric power to units of flight vehicle  10 , including driving apparatuses  102 . 
       FIG. 3  is a diagram showing the hardware configuration of flight vehicle  10 . Flight vehicle  10  is physically configured as a computer apparatus that includes processor  11 , memory  12 , storage  13 , communication apparatus  14 , positioning apparatus  15 , image capturing apparatus  16 , sensor  18 , bus  17 , and the like. Note that in the following description, the term “apparatus” can be replaced with terms such as circuit, device, and unit. 
     Processor  11  runs an operating system and performs overall control of the computer, for example. Processor  11  may be configured by a CPU (Central Processing Unit) that includes a control apparatus, an arithmetic operation apparatus, a register, an interface for peripheral apparatuses, and the like. 
     Also, processor  11  reads out programs (program code), software modules, and data from storage  13  and/or communication apparatus  14  to memory  12 , and accordingly executes various types of processing. One program is a program for causing the computer to execute at least part of the operations of flight vehicle  10 . The various types of processing executed in flight vehicle  10  may be executed by one processor  11 , or may be executed by two or more processors  11  simultaneously or consecutively. Processor  11  may be mounted on one or more chips. Note that the program may have been transmitted from the network via an electrical communication line. 
     Memory  12  is a computer-readable recording medium, and may be configured by one or more of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), and the like. Memory  12  may be called a register, a cache, a main memory (main storage apparatus), or the like. Memory  12  can hold, for example, software modules and programs (program code) that can be executed in order to carry out a flight control method according to an embodiment of the present invention. 
     Storage  13  is a computer-readable recording medium, and may be configured by at least one of an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, or a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, or a key drive), a Floppy (registered trademark) disk, and a magnetic strip. Storage  13  may also be called an auxiliary storage apparatus. 
     Communication apparatus  14  is hardware for performing wireless communication with first piloting terminal  30 . 
     Positioning apparatus  15  measures the three-dimensional position of flight vehicle  10 . For example, positioning apparatus  15  is a GPS (Global Positioning System) receiver and measures the current position of flight vehicle  10  based on GPS signals that are received from a plurality of satellites. 
     Image capturing apparatus  16  captures images of the surroundings of flight vehicle  10 . For example, image capturing apparatus  16  is a camera, and captures images by forming an image on an imaging element with use of an optical system. Image capturing apparatus  16  captures images of a predetermined range in front of flight vehicle  10  for example. It should be noted that the image capturing direction of image capturing apparatus  16  is not limited to being in front of flight vehicle  10 , and may be above, below, or behind flight vehicle  10 . Also, the image capturing direction may be changed by rotation of a platform that supports image capturing apparatus  16 , for example. 
     Sensor  18  is a device for sensing various states of flight vehicle  10 , and detects the altitude of flight vehicle  10 , the speed of flight vehicle  10 , the orientation of flight vehicle  10 , the battery amount of flight vehicle  10 , the motor rotation speeds of flight vehicle  10 , and the distance between flight vehicle  10  and a work object, for example. Note that in the case where flight vehicle  10  is capturing images of a building for example, the work object is that building. 
     Apparatuses such as processor  11  and memory  12  described above are connected by bus  17  in order to exchange information. Bus  17  may be configured by a single bus, or may be configured by different buses that connect apparatuses. 
       FIG. 4  is a diagram showing the hardware configuration of first piloting terminal  30 . First piloting terminal  30  is physically configured as a computer apparatus that includes processor  31 , memory  32 , storage  33 , first communication apparatus  34 , second communication apparatus  35 , UI (User Interface) unit  36 , bus  37 , and the like. First communication apparatus  34  performs wireless communication with communication apparatus  14  of flight vehicle  10 . Second communication apparatus  35  performs communication with server apparatus  20  via network  60 . UI unit  36  includes a display unit that has a liquid crystal panel, a liquid crystal drive circuit, and the like, and displays images based on image data, and also includes an operation unit that has operators such as keys or a touch sensor and receives user operations and supplies signals corresponding to such operations to processor  31 . The other units, namely processor  31 , memory  32 , storage  33 , and bus  37 , are similar to processor  11 , memory  12 , storage  13 , and bus  17  that were described above, and therefore descriptions will not be given for them. 
       FIG. 5  is a diagram showing the hardware configuration of second piloting terminal  50 . Second piloting terminal  50  is physically configured as a computer apparatus that includes processor  51 , memory  52 , storage  53 , communication apparatus  54 , UI unit  55 , bus  56 , and the like. Communication apparatus  54  performs communication with server apparatus  20  via network  60 . The other units, namely processor  51 , memory  52 , storage  53 , UI unit  55 , and bus  56 , are similar to processor  11 , memory  12 , storage  13 , UI unit  36 , and bus  17  that were described above, and therefore descriptions will not be given for them. 
       FIG. 6  is a diagram showing the hardware configuration of server apparatus  20 . Server apparatus  20  is physically configured as a computer apparatus that includes processor  21 , memory  22 , storage  23 , communication apparatus  24 , bus  25 , and the like. Communication apparatus  24  performs communication with first piloting terminal  30  and second piloting terminal  50  via network  60 . Processor  21 , memory  22 , storage  23 , and bus  25  are similar to processor  11 , memory  12 , storage  13 , and bus  17  that were described above, and therefore descriptions will not be given for them. 
       FIG. 7  is a diagram showing an example of the functional configuration of server apparatus  20 . Various functions of server apparatus  20  are realized by predetermined software (program) being loaded to hardware such as processor  21  and memory  22 , such that processor  21  performs arithmetic computation and controls communication performed by communication apparatus  24  and the reading and/or writing of data from/to memory  22  and storage  23 . 
     In  FIG. 7 , tracking unit  200  records flight vehicle identification information corresponding to flight vehicle  10  that is under control of server apparatus  20 , and also records the flight status of flight vehicle  10 . The flight status includes positions at which flight vehicle  10  is flying, and date/times of such positions. Tracking unit  200  records position information and date/time information that are notified by flight vehicle  10  via first piloting terminal  30 . Tracking unit  200  also determines whether or not the position information and the date/time information are within a flight plan that has been planned in advance, and records the determination results. 
     First acquisition unit  201  acquires, via first piloting terminal  30 , flight vehicle viewpoint images that were captured by image capturing apparatus  16  included in flight vehicle  10 . Second acquisition unit  202  acquires, from image capturing apparatus  40 , pilot viewpoint images of the flight of flight vehicle  10  captured by image capturing apparatus  40 . 
     Priority display control unit  203  causes either the flight vehicle viewpoint images acquired by first acquisition unit  201  or the pilot viewpoint images acquired by second acquisition unit  202  to be displayed with priority on second piloting terminal  50 . Priority display control unit  203  also causes information regarding the flight of the flying flight vehicle  10  to be displayed on second piloting terminal  50 . 
     First communication unit  204  performs communication with first piloting terminal  30  for wirelessly piloting flight vehicle  10 . Second communication unit  205  performs communication with second piloting terminal  50  for piloting flight vehicle  10  via network  60 . Determination unit  206  determines whether first piloting terminal  30  or second piloting terminal  50  is to pilot flight vehicle  10 , based on information that first communication unit  204  received from first piloting terminal  30 . More specifically, determination unit  206  specifies a piloting experience level corresponding to first piloting terminal  30  based on information that first communication unit  204  received from first piloting terminal  30 , and makes the aforementioned determination based on the specified experience level. 
     In a case of a determination that second piloting terminal  50  is to pilot flight vehicle  10 , remote control unit  207  transfers instructions for flight vehicle  10  that were received from second piloting terminal  50  to flight vehicle  10 . More specifically, in a case of a determination that second piloting terminal  50  is to pilot flight vehicle  10 , remote control unit  207  uses first communication unit  204  to notify first piloting terminal  30  that flight vehicle  10  is to be piloted by second piloting terminal  50 , and upon receiving permission in response to the notification, transfers instructions for flight vehicle  10  received from second piloting terminal  50  to flight vehicle  10 . In this way, flight vehicle  10  flies in accordance with instructions from first piloting terminal  30  in some cases, and flies in accordance with instructions from second piloting terminal  50  in other cases. 
       FIG. 8  shows an example of a display image determination table having described therein conditions for determining whether either flight vehicle viewpoint images or pilot viewpoint images are to be displayed with priority in the second piloting terminal. The display image determination table is stored in storage  23  of server apparatus  20 . Priority display control unit  203  determines which captured images are to be displayed with priority based on information regarding the flight of flight vehicle  10 , and in the present embodiment in particular, priority display control unit  203  determines which captured images are to be displayed with priority based on an in-flight state of flight vehicle  10 . 
     Here, in-flight states include states detected by sensor  18  of flight vehicle  10 , such as the altitude, speed, orientation, battery amount, and motor rotation speeds of flight vehicle  10 , as well as the distance to the work object. For example, in the case of determining which captured images are to be displayed based on the condition “altitude”, the flight vehicle viewpoint images are displayed with priority if the altitude of flight vehicle  10  is greater than or equal to a threshold value H, and the pilot viewpoint images are displayed with priority if the altitude is less than the threshold value H. In other words, when the altitude of flight vehicle  10  is considered to be the condition, the determination of which captured images are to be displayed with priority is made from the viewpoint of whether the piloting assister can more easily provide assistance while viewing the flight vehicle viewpoint images or while viewing the pilot viewpoint images. According to this viewpoint, the determination of which captured images are to be displayed with priority is made in consideration of conditions other than altitude as well, namely the speed, orientation, battery amount, and motor rotation speeds of flight vehicle  10 , and the distance to the work object. 
       FIG. 9  shows an example of a main pilot determination table having described therein conditions for determining whether first piloting terminal  30  or second piloting terminal  50  is to be the main pilot. The main pilot determination table is stored in the storage  23  of server apparatus  20 . Based on information that first communication unit  204  received from first piloting terminal  30 , determination unit  206  specifies the piloting experience level of the pilot and the difficulty level of the piloting performed by the pilot, determines that the pilot is to be the main pilot if the piloting experience level of the pilot is greater than or equal to the piloting difficulty level, and determines that the piloting assister is to be the main pilot if the piloting experience level of the pilot is less than the piloting difficulty level. Operations 
       FIG. 10  is a sequence chart showing an example of operations of flight control system  1 . In cases where it is described that flight vehicle  10  is performing processing in the following description, this specifically means that processing is executed by predetermined software (program) being loaded to hardware such as processor  11  and memory  12 , such that processor  11  performs arithmetic computation and controls communication performed by communication apparatus  14  and the reading and/or writing of data from/to memory  12  and storage  13 . The same follows for server apparatus  20 , first piloting terminal  30 , and second piloting terminal  50  as well. 
     When flight vehicle  10  starts to fly, image capturing apparatus  16  of flight vehicle  10  starts to capture images (step S 11 ). Moving image data including the captured images is wirelessly transmitted from communication apparatus  14  of flight vehicle  10  to first piloting terminal  30  (step S 12 ). At this time, flight vehicle  10  wirelessly transmits, from communication apparatus  14  to first piloting terminal  30 , flight-related information that was detected by positioning apparatus  15  and sensor  18  (including the date/time, the position of flight vehicle  10 , the altitude of flight vehicle  10 , the speed of flight vehicle  10 , the orientation of flight vehicle  10 , the battery amount of flight vehicle  10 , the motor rotation speeds of flight vehicle  10 , the distance between flight vehicle  10  and the work object, and the like). First piloting terminal  30  transmits, to server apparatus  20 , the flight-related information and the moving image data including the captured images that were received from flight vehicle  10  (step S 13 ). Note that flight-related information that can be generated by first piloting terminal  30  (e.g., the date/time) may be generated by first piloting terminal  30  and transmitted to server apparatus  20 . 
     Also, image capturing apparatus  40  starts to capture images in accordance with a start imaging operation performed by the pilot (step S 14 ). Moving image data including the captured images is transmitted from image capturing apparatus  40  to server apparatus  20  (step S 15 ). Accordingly, first acquisition unit  201  of server apparatus  20  acquires flight-related information and moving image data including captured images (flight vehicle viewpoint images) from image capturing apparatus  16 , and second acquisition unit  202  of server apparatus  20  acquires moving image data including captured images (pilot viewpoint images) from image capturing apparatus  40 . 
     Next, first communication unit  204  and second communication unit  205  of server apparatus  20  relay audio communication between first piloting terminal  30  and second piloting terminal  50  (step S 16 ). Accordingly, the pilot and the piloting assister can communicate through audio. Through this audio communication, the piloting assister can provide advice for assisting the piloting of the pilot. 
     Priority display control unit  203  of server apparatus  20  references the display image determination table and the flight-related information and determines the captured images that are to be displayed on second piloting terminal  50  (step S 17 ). Specifically, priority display control unit  203  applies the acquired flight-related information to the display image determination table and determines that the display target is the captured images that correspond to such information. At this time, there are cases where the determined captured images differ according to various conditions, such as the flight vehicle viewpoint images being the determined display target if focus is placed on the condition “altitude”, and the pilot viewpoint images being the determined display target if focus is placed on the condition “speed”. At this time, the display target may be determined to be the captured images that match the highest number of conditions, for example. Furthermore, the conditions may be weighted when making a determination. For example, the weight of 1.1 may be assigned for a display target that is determined when focus is placed on the condition “altitude”, and the weight of 1.3 may be assigned for a display target that is determined when focus is placed on the condition “speed”. 
     Priority display control unit  203  of server apparatus  20  transmits the moving image data that includes the captured images determined to be the display target to second piloting terminal  50 , thus performing display control for causing those captured images to be displayed with priority on second piloting terminal  50  (steps S 18  and S 19 ). Second piloting terminal  50  displays images in accordance with the moving image data that includes the captured images that were determined to be the display target (step S 20 ). At this time, server apparatus  20  uses second communication unit  205  to transmit, to second piloting terminal  50 , information that first communication unit  204  received from first piloting terminal  30  (e.g., the position of flight vehicle  10 , the altitude of flight vehicle  10 , the speed of flight vehicle  10 , the orientation of flight vehicle  10 , the battery amount of flight vehicle  10 , the motor rotation speeds of flight vehicle  10 , the distance between flight vehicle  10  and the work object), and causes such information to be output by audio in second piloting terminal  50 . By listening to such audio, the piloting assister can determine the content of the advice for assisting piloting. Note that such information may be displayed on second piloting terminal  50 . 
     The pilot pilots flight vehicle  10  by operating first piloting terminal  30  (step S 21 ). At this time, in first piloting terminal  30 , operation instructions for flight vehicle  10  are wirelessly transmitted from first communication apparatus  34  (step S 22 ), and information necessary for specifying the piloting experience level of the pilot of first piloting terminal  30  (e.g., the position of flight vehicle  10  detected by positioning apparatus  15  and sensor  18  of flight vehicle  10 , the altitude of flight vehicle  10 , the speed of flight vehicle  10 , the orientation of flight vehicle  10 , the battery amount of flight vehicle  10 , the motor rotation speeds of flight vehicle  10 , and the distance between flight vehicle  10  and the work object) is transmitted from second communication apparatus  35  to server apparatus  20  (step S 23 ). 
     First communication unit  204  of server apparatus  20  acquires the above-described information necessary for specifying the piloting experience level of the pilot of first piloting terminal  30 . Determination unit  206  determines whether first piloting terminal  30  or second piloting terminal  50  is to be the main pilot of flight vehicle  10 , based on the information that first communication unit  204  received from first piloting terminal  30  (step S 24 ). 
     First, determination unit  206  specifies the piloting experience level with respect to first piloting terminal  30  based on the information that first communication unit  204  received from first piloting terminal  30 . For example, in the case where changes in the position of flight vehicle  10 , changes in the speed of flight vehicle  10 , changes in orientation of flight vehicle  10 , and the like are in predetermined ranges, that is to say in the case where there are no rapid changes in the flight of flight vehicle  10 , and it can be inferred that reasonable and smooth flight control is being performed, then determination unit  206  determines that the piloting experience level with respect to first piloting terminal  30  is high. However, in the case where changes in the position of flight vehicle  10 , changes in the speed of flight vehicle  10 , changes in orientation of flight vehicle  10 , and the like are outside of the predetermined ranges, that is to say in the case where the flight of flight vehicle  10  is unreasonable, then determination unit  206  determines that the piloting experience level with respect to first piloting terminal  30  is low. 
     Next, determination unit  206  specifies the difficulty level of the piloting of flight vehicle  10  based on the information that first communication unit  204  received from first piloting terminal  30 . For example, the higher the altitude of flight vehicle  10  is, and the smaller the battery amount of flight vehicle  10  is, or the closer the distance between flight vehicle  10  and the work object is, that is to say the higher the match with predetermined conditions deemed to result in difficult piloting of flight vehicle  10  is, then the higher determination unit  206  determines the difficulty level of the piloting of flight vehicle  10  to be. In this way, based on information that first communication unit  204  received from first piloting terminal  30 , determination unit  206  specifies the piloting experience level of the pilot and the difficulty level of the piloting performed by the pilot, determines that the pilot is to be the main pilot if the piloting experience level of the pilot is greater than or equal to the piloting difficulty level, and determines that the piloting assister is to be the main pilot if the piloting experience level of the pilot is less than the piloting difficulty level. 
     Here, in a case where determination unit  206  determined that the main pilot is to be the pilot, piloting of flight vehicle  10  continues to be performed by the pilot with use of first piloting terminal  30 . On the other hand, in a case where determination unit  206  determined that the main pilot is to be the piloting assister, piloting of flight vehicle  10  is to be performed by the piloting assister with use of second piloting terminal  50 . First, using first communication unit  204 , remote control unit  207  notifies first piloting terminal  30  that flight vehicle  10  is to be operated by second piloting terminal  50  (step S 25 ). When this notification is output to first piloting terminal  30 , and the pilot performs an operation signifying permission for the notification, first piloting terminal  30  transmits permission for the notification to server apparatus  20  (step S 26 ). Remote control unit  207  notifies second piloting terminal  50  that the main pilot is to be changed from first piloting terminal  30  to second piloting terminal  50  (step S 27 ). 
     The piloting assister receives the aforementioned notification, and pilots flight vehicle  10  by operating second piloting terminal  50  (step S 28 ). At this time, as previously described, priority display control unit  203  of server apparatus  20  transmits the moving image data that includes the captured images determined to be the display target to second piloting terminal  50 , thus performing display control for causing those captured images to be displayed with priority on second piloting terminal  50 , and therefore the piloting as sister can pilot flight vehicle  10  while viewing such images. In accordance with operations performed by the piloting assister, second piloting terminal  50  transmits operation instructions for flight vehicle  10  to server apparatus  20  (step S 29 ). Remote control unit  207  of server apparatus  20  transfers operation instructions for flight vehicle  10  that were received from second piloting terminal  50  to flight vehicle  10 , thus performing remote control of flight vehicle  10  (steps S 30  and S 31 ). Such instructions are transmitted to flight vehicle  10  via first piloting terminal  30  (step S 32 ), and flight vehicle  10  flies in accordance with such instructions. Subsequently, the piloting assister continues to pilot flight vehicle  10  by operating second piloting terminal  50 . 
     According to the embodiment described above, the piloting as sister can easily give piloting assistance from a remote location. Also, images that are appropriate for the piloting assistance are displayed to the piloting assister with priority, thus contributing to the piloting assistance given from a remote location. Variations 
     The present invention is not limited to the embodiment described above. The above-described embodiment may be modified as described below. Also, two or more of the following variations may be implemented in combination with each other. 
     Variation 1 
     Determination unit  206  determined the main pilot based on information that first communication unit  204  received from first piloting terminal  30 , but may determine the main pilot based on information that the second communication unit  205  received from second piloting terminal  50 . Specifically, determination unit  206  determines whether first piloting terminal  30  or second piloting terminal  50  is to be the pilot of flight vehicle  10  based on information that first communication unit  204  received from first piloting terminal  30  or information that second communication unit  205  received from second piloting terminal  50 . For example, after the main pilot has changed to the piloting assister, if second communication unit  205  acquires information indicating piloting content from second piloting terminal  50 , determination unit  206  may specify the difficulty level of the piloting of flight vehicle  10  based on the acquired information, and determine that the main pilot is to be reverted to the pilot if the difficulty level is lower than a pilot piloting experience level that has been specified in advance. 
     Variation 2 
     A configuration is possible in which, instead of operation instructions for flight vehicle  10  that were received from second piloting terminal  50  being transferred to flight vehicle  10  via first piloting terminal  30 , in a case where flight vehicle  10  can directly connect to and perform communication on network  60 , such operation instructions are transferred to flight vehicle  10  via network  60  without passing through first piloting terminal  30 . 
     Variation 3 
     The conditions used when determination unit  206  determines the main pilot are not limited to the examples given in the embodiment. For example, determination unit  206  may specify the flight environment of flight vehicle  10  based on information that first communication unit  204  received from first piloting terminal  30 , and make the determination based on the specified flight environment. The flight environment mentioned here includes, for example, wind-related information such as wind direction and wind speed, and weather-related information such as clear sky, clouds, fog, rain, snow, and thunder. First piloting terminal  30  acquires information for specifying such conditions by measurement on its own or from a predetermined measurement apparatus, and transmits the acquired information to server apparatus  20 . Determination unit  206  of server apparatus  20  specifies the difficulty level of the flight of flight vehicle  10  based on such flight environment conditions. 
     Variation 4 
     Also, determination unit  206  may specify states of flight vehicle  10  based on information that first communication unit  204  received from first piloting terminal  30 , and make the determination based on the specified states, for example. The states of the flight vehicle referred to here are “function problem”, “operation problem”, and the like, and first piloting terminal  30  acquires information for specifying such states by measurement on its own, and transmits the acquired information to server apparatus  20 . Determination unit  206  of server apparatus  20  specifies the difficulty level of the flight of flight vehicle  10  based on such flight states. Variation  5   
     In a case where there are a plurality of piloting assisters for one or more pilots, remote control may be performed as follows. Specifically, in a case where there are a plurality of sets of first piloting terminal  30  and second piloting terminal  50  (when counting the sets, one first piloting terminal  30  may be counted in multiple sets), determination unit  206  determines the main pilot for each set of first piloting terminal  30  and second piloting terminal  50 , and, for each set of first piloting terminal  30  and second piloting terminal  50 , if it is determined that flight vehicle  10  is to be piloted by second piloting terminal  50 , remote control unit  207  transfers instructions for flight vehicle  10  that are received from second piloting terminal  50  to flight vehicle  10 . For example, in a case where there are two second piloting terminals  50  (i.e., in a case where there are two piloting assisters), assume that one second piloting terminal  50  is a terminal for assisting the piloting of flight vehicle  10  by the pilot, and that the other second piloting terminal  50  is a terminal for assisting image capturing performed by the pilot with use of flight vehicle  10 . In this case, the piloting assisters can each perform operations for image capturing or flight of flight vehicle  10  in accordance with their own assistance objectives by using their second piloting terminals  50  while viewing corresponding images. According to this configuration, it is possible to realize an aspect in which a plurality of piloting assisters can provide piloting assistance to one pilot. 
     Variation 6 
     When images are to be displayed with priority, the conditions for determining the display target captured images are not limited to the example of the embodiment. For example, priority display may be performed in accordance with piloting information regarding piloting operations performed by the pilot on first piloting terminal  30 , such as operation amounts, operation directions, and operation frequency. In this example, storage  23  stores a display image determination table having described therein piloting information-related conditions for determining whether the flight vehicle viewpoint images or the pilot viewpoint images are to be displayed with priority. When first acquisition unit  201  acquires the aforementioned pilot piloting-related information from first piloting terminal  30 , priority display control unit  203  references the display image determination table based on such information and determines the captured images that are to be displayed with priority. For example, the captured images that are to be displayed with priority are different between cases where the pilot piloting experience level is determined to be high based on the piloting information, or the piloting itself is easy, and cases where the pilot piloting experience level is determined to be low based on the piloting information, or the piloting itself is difficult. According to this configuration, it is possible to realize piloting assistance that corresponds to piloting content. 
     Variation 7 
     Also, the display priority determination may be made in accordance with attributes such as the piloting proficiency or the piloting experience of the pilot or the piloting assister. In this example, storage  23  stores a display image determination table having described therein conditions that are related to attributes of the pilot or the piloting as sister for determining whether the flight vehicle viewpoint images or the pilot viewpoint images are to be displayed with priority. Priority display control unit  203  identifies the pilot or the piloting assister that is logged into the system, references the display image determination table based on the attributes of the identified person, and determines the captured images that are to be displayed with priority. For example, the captured images that are to be displayed with priority are different between cases where, based on the attributes, the pilot piloting experience level is determined to be high, the piloting assister piloting experience is determined to be high, the pilot piloting experience level is determined to be low, and the piloting as sister piloting experience is determined to be low. According to this configuration, it is possible to realize piloting assistance that corresponds to such attributes. 
     Variation 8 
     The display priority determination may be made in accordance with the content of the piloting assistance provided by the piloting as sister. In this example, storage  23  stores a display image determination table having described therein piloting assistance-related conditions for determining whether the flight vehicle viewpoint images or the pilot viewpoint images are to be displayed with priority. Priority display control unit  203  acquires piloting assistance-related information (e.g., high/low assistance level, or assistance complexity/simplicity) provided by the piloting assister from second piloting terminal  50 , references the display image determination table based on such information, and determines the captured images that are to be displayed with priority. For example, the captured images that are to be displayed with priority are different between cases where, based on the piloting assistance content, the piloting assistance level is determined to be high, or the piloting assistance itself is easy, and cases where the piloting assistance level is determined to be low, or the piloting assistance itself is difficult. According to this configuration, it is possible to realize piloting assistance that corresponds to such content of piloting assistance. 
     Variation 9 
     In a case where there are a plurality of piloting assisters for one pilot, the priority display determination may be made as follows. Specifically, in a case where there are a plurality of second piloting terminals  50 , priority display control unit  203  determines the captured images that are to be displayed with priority in accordance with methods determined for respective second piloting terminals  50 . For example, in a case where one second piloting terminal  50  is a terminal for supporting flight of flight vehicle  10  by a pilot, and another second piloting terminal  50  is a terminal for assisting image capturing performed by the pilot with use of flight vehicle  10 , it is determined that the images to be displayed with priority on the one second piloting terminal  50  are the pilot viewpoint images, which are more useful for flight assistance, and it is determined that the images to be displayed with priority on the other second piloting terminal  50  are the flight vehicle viewpoint images, which are more useful for image capturing assistance. The piloting assisters thus operate the respective second piloting terminals  50  in accordance with their own assistance objectives while viewing the respective images. According to this configuration, it is possible to realize an aspect in which a plurality of piloting assisters can provide piloting assistance to one pilot. Variation  10   
     In a case where there are a plurality of flight vehicles  10  and pilots for one piloting assister, the priority display determination may be made as follows. First acquisition unit  201  acquires captured images that were captured by image capturing apparatuses  16  included in the respective flight vehicles  10 , and second acquisition unit  202  acquires captured images that show the flight of the respective flight vehicles  10 . For each flight vehicle  10 , priority display control unit  203  selects the captured images acquired by first acquisition unit  201  or the captured images acquired by second acquisition unit  202  in accordance with the objective of piloting assistance for each pilot, and causes the selected captured images to be displayed with priority on the terminal in the possession of the piloting assister. For example, in a case of providing flight assistance for first flight vehicle  10  to one first piloting terminal  30 , and providing image capturing assistance for second flight vehicle  10  to another first piloting terminal  30 , when providing assistance to the one first piloting terminal  30 , the captured images that are displayed with priority on the one second piloting terminal  50  are the pilot viewpoint images that show the flight of first flight vehicle  10 , and when providing assistance to the other first piloting terminal  30 , the captured images that are displayed with priority on the one second piloting terminal  50  are the flight vehicle viewpoint images that were captured by second flight vehicle  10 . By operating second piloting terminal  50  while viewing these images, the one piloting assister can provide assistance to two pilots at the same time or alternatingly. According to this configuration, it is possible to realize a case where one piloting assister provides piloting assistance to a plurality of pilots. 
     Variation 11 
     Information related to latency in network  60  may be displayed on second piloting terminal  50 . In other words, priority display control unit  203  may cause information related to delay in data communication between own server apparatus  20  and second piloting terminal  50  to be displayed on second piloting terminal  50 . Such information is also useful in piloting assistance. 
     Variation 12 
     Captured images designated by the piloting assister may be displayed with priority on second piloting terminal  50 . The captured images that are to be displayed with priority on second piloting terminal  50  may be determined in consideration of the weather forecast. 
     Variation 13 
     Any method may be used to follow flight vehicle  10  while capturing images. Also, the method for measuring the position of flight vehicle  10  is not limited to a method employing GPS, and any method may be used. Also, a configuration is possible in which flight vehicle  10  is configured to be capable of performing communication via network  60 , and flight vehicle  10  performs communication with server apparatus  20  or second piloting terminal  50  without passing through first piloting terminal  30 . 
     Other Variations 
     The block diagrams used in the above description of the embodiments shows blocks in units of functions. These functional blocks (configuration units) are realized by any combination of hardware and/or software. Furthermore, there are no particular limitations on the means for realizing the functional blocks. In other words, the functional blocks may be realized by one physically and/or logically combined apparatus, or a plurality of physically and/or logically separated apparatuses that are connected directly and/or indirectly (for example, in a wired and/or wireless manner). Also, at least some of the functions of server apparatus  20  may be implemented in first piloting terminal  30  or second piloting terminal  50 . Similarly, at least some of the functions of first piloting terminal  30  or second piloting terminal  50  may be implemented in server apparatus  20 . 
     The aspects/embodiments explained in the present description may also be applied to a system using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G, 5G, Future Radio Access (FRA), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark) or another appropriate system, and/or an extended next-generation system that is based on them. 
     The orders in the processing procedures, sequences, flowcharts, and the like of the aspects/embodiments described in the present description may be changed as long as no contradictions arise. For example, the methods explained in the present description show various step elements in an exemplified order, and are not limited to the specific order that is shown. 
     The aspects/embodiments described in the present description may also be used alone or in combination, or may also be switched when they are implemented. Furthermore, the notification of predetermined information (e.g., notification of “being X”) is not limited to being performed explicitly, and may also be performed implicitly (for example, notification of the predetermined information is not performed). 
     The terms “system” and “network” used in the present description can be used in an interchangeable manner. 
     The information and the parameters described in the present description may also be expressed by absolute values, relative values with respect to a predetermined value, or another type of corresponding information. For example, a radio resource may also be one indicated by an index. 
     The names used for the above-described parameters are in no way limiting. Furthermore, there may be a case where formulae and the like using these parameters are different from those explicitly disclosed in the present description. Various channels (such as, for example, a PUCCH and a PDCCH) and information elements (such as, for example, a TPC) can be identified by any suitable name, and thus various names assigned to these various channels and information elements are no way limiting. 
     The term “determining” used in the present description may include various types of operations. The term “determining” can include a case where judging, calculating, computing, processing, deriving, investigating, looking up (for example, looking up a table, a data base, or another data structure), or ascertaining is regarded as “determining”. Furthermore, the term “determining” can include a case where receiving (for example, receiving information), transmitting (for example, transmitting information), inputting, outputting, or accessing (for example, accessing data in the memory) is regarded as “determining”. Furthermore, the term “determining” can include a case where resolving, selecting, choosing, establishing, or comparing is regarded as “determining”. In other words, the term “determining” can include a case where some operation is regarded as “determining”. 
     The present invention may be provided as a flight control method that includes the processing steps performed in flight control system  1 . Also, the present invention may be provided as a program that is executed in server apparatus  20 , flight vehicle  10 , first piloting terminal  30 , or second piloting terminal  50 . This program may be provided in an aspect of being recorded on a recording medium such as an optical disk, or may be provided in an aspect of being downloaded to a computer via a network such as the Internet and being installed in the computer to become usable, for example. 
     Software, instructions, and the like may also be transmitted/received via a transmission medium. For example, if software is transmitted from a web site, a server, or another remote source using a wired technology such as a coaxial cable, an optical fiber cable, a twisted-pair wire, or a digital subscriber line (DSL), and/or a wireless technology using infrared light, radio waves, microwaves, or the like, the definition of the transmission medium will include the wired technology and/or the wireless technology. 
     Information, signals, and the like described in the present description may also be expressed using any of various different technologies. For example, data, an instruction, a command, information, a signal, a bit, a symbol, a chip, and the like that may be mentioned throughout the entire description above may also be expressed by an electric voltage, an electric current, an electromagnetic wave, a magnetic field or a magnetic particle, an optical field or a photon, or an arbitrary combination thereof. 
     Note that the terms described in the present description and/or the terms needed for understanding the present description may also be replaced by terms that have the same or similar meaning. For example, a channel and/or a symbol may also be a signal. Furthermore, a signal may also be a message. Furthermore, a component carrier (CC) may also be referred to as a carrier frequency, a cell, or the like. 
     All references to elements that have been given names such as “first” and “second” in the present description do not overall limit the number of such elements or the orders thereof. Such names may be used in the present description as a convenient method for distinguishing between two or more elements. Accordingly, references to first and second elements are not intended to mean that only two elements can be employed, or that the first element is required to come before the second element in some sort of manner. 
     The “means” in the configurations of the above-described apparatuses may be replaced by “unit”, “circuit”, “device”, or the like. 
     The terms “including”, “comprising”, and other forms thereof are intended to be comprehensive as long as they are used in the present description or the claims, similar to the term “being provided with”. Furthermore, the term “or” used in the present description or the claims is intended not to be exclusive OR. 
     In the entirety of the present disclosure, when articles are added through translation, for example, as “a”, “an”, and “the” in English, these articles also denote the plural form unless it is clear otherwise from the context. 
     While the present invention has been described in detail, it would be obvious to those skilled in the art that the present invention is not limited to the embodiments explained in the present description. The present invention can be implemented as corrected and modified aspects without departing from the spirit and scope of the present invention that are defined by the description of the claims. Accordingly, the present description aims to illustrate examples and is not intended to restrict the present invention in any way. 
     REFERENCE SIGNS LIST 
       1  flight control system 
       10  flight vehicle 
       20  server apparatus 
       21  processor 
       22  memory 
       23  storage 
       24  communication apparatus 
       200  tracking unit 
       201  first acquisition unit 
       202  second acquisition unit 
       203  priority display control unit 
       204  first communication unit 
       205  second communication unit 
       206  determination unit 
       207  remote control unit 
       30  first piloting terminal 
       40  image capturing apparatus 
       50  second piloting terminal.