Patent Publication Number: US-2021182757-A1

Title: Server device, information processing system, non-transitory storage medium, and method for operating information processing system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2019-224679 filed on Dec. 12, 2019, which is incorporated herein by reference in its entirety, including the specification, drawings and abstract. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to server a device, an information processing system, a non-transitory storage medium, and a method for operating an information processing system. 
     2. Description of Related Art 
     Japanese Unexamined Patent Application Publication No. 2004-341872 (JP 2004-341872 A) discloses a technique of dispatching a taxi via a communication channel. 
     SUMMARY 
     This technique has room for improvement in convenience of vehicle dispatch services. 
     The present disclosure provides a technique that improves the convenience of vehicle dispatch services. 
     A first aspect of the present disclosure is a server device. The server device includes a communication unit configured to communicate with a plurality of terminal devices and a control unit. The control unit is configured to mediate transmission and reception of information between the terminal devices via the communication unit and configured to transmit a dispatch message including an offer to dispatch a vehicle to a first terminal device when an image object indicating a necessity of dispatching a vehicle is transmitted from the first terminal device to a second terminal device. 
     In the first aspect, the control unit may be configured to dispatch a vehicle to a location of the first terminal device when the control unit receives an acceptance of the offer of the dispatch message from the first terminal device. 
     In the first aspect, the control unit may be configured to transmit the dispatch message to the first terminal device when a dispatch condition is satisfied. The dispatch condition may be a condition regarding at least one of a location of the first terminal device when the first terminal device transmits the image object to the second terminal device and a time when the first terminal device transmits the image object to the second terminal device. 
     In the first aspect, the dispatch condition may be that the location of the first terminal device when the first terminal device transmits the image object is different from an address of a user of the first terminal device. 
     In the first aspect, the dispatch condition may be that movement of the location of the first terminal device when the first terminal device transmits the image object is different from movement by a vehicle. 
     In the first aspect, the dispatch condition may be that the time when the first terminal device transmits the image object is outside operating hours of public transportation. 
     In the first aspect, the control unit may be configured to determine whether the image object indicates the necessity of dispatching the vehicle, based on a transmission manner in which the first terminal device transmitted the image object to the second terminal device in past. 
     In the first aspect, the transmission manner may be that a text message transmitted or received by the first terminal device to or from the second terminal device in association with the image object includes a predetermined keyword. 
     In the first aspect, the transmission manner may be that a location of the first terminal device when the first terminal device transmitted the image object is different from an address of a user of the first terminal device. 
     In the first aspect, the transmission manner may be that movement of a location of the first terminal device when the first terminal device transmitted the image object is different from movement by a vehicle. 
     In the first aspect, the transmission manner may be that a time when the first terminal device transmitted the image object is outside operating hours of public transportation. 
     In the first aspect, the control unit may be configured to reduce a fare for the dispatched vehicle in accordance with the number of times the first terminal device transmits the image object to the second terminal device. 
     In the first aspect, the control unit may be configured to transmit the image object to the second terminal device after the first terminal device performs a process of purchasing the image object from a vehicle dispatch service provider. 
     A second aspect of the present disclosure is an information processing system. The information processing system includes a first terminal device and a server device including a communication unit and a control unit. The communication unit is configured to communicate with a plurality of terminal devices. The control unit is configured to mediate transmission and reception of information between the terminal devices via the communication unit and configured to transmit a dispatch message including an offer to dispatch a vehicle to the first terminal device when an image object indicating a necessity of dispatching a vehicle is transmitted from the first terminal device to a second terminal device. 
     A third aspect of the present disclosure is a non-transitory storage medium. The non-transitory storage medium stores instructions that are executable by one or more processors and that cause the one or more processors to perform functions. The functions include: transmitting an image object indicating a necessity of dispatching a vehicle to a second terminal device via a server device configured to transmit and receive information to and from a first terminal device; and receiving from the server device a dispatch message including an offer to dispatch a vehicle. 
     In the third aspect, the functions may further include causing the server device to dispatch a vehicle to a location of the first terminal device, by transmitting an acceptance of the offer of the dispatch message from the first terminal device to the server device. 
     In the third aspect, the functions may further include: transmitting the image object to the second terminal device after performing a process for purchasing the image object from a vehicle dispatch service provider. 
     A fourth aspect of the present disclosure is a method for operating an information processing system. The information processing system includes plurality of terminal devices and a server device configured to mediate transmission and reception of information between or among the terminal devices. The method for operating the information processing system includes transmitting a dispatch message including an offer to dispatch a vehicle from the server device to a first terminal device when an image object indicating a necessity of dispatching a vehicle is transmitted from the first terminal device to a second terminal device. 
     In the fourth aspect, the method for operating the information processing system may further include causing the server device to dispatch a vehicle to a location of the first terminal device when the server device receives an acceptance of the offer of the dispatch message from the first terminal device. 
     In the fourth aspect, the method for operating the information processing system may further include: reducing a fare for the dispatched vehicle in accordance with the number of times the first terminal device transmitted the image object to the second terminal device. 
     According to the first, second, third, and fourth aspects of the present disclosure, the convenience of vehicle dispatch services is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: 
         FIG. 1  illustrates a configuration example of an information processing system; 
         FIG. 2  illustrates a configuration example of a terminal device; 
         FIG. 3  illustrates a configuration example of a server device; 
         FIG. 4  illustrates a configuration example of an on-board device; 
         FIG. 5  illustrates an example of a sequence of operations of the information processing system; 
         FIG. 6  illustrates an example of a sequence of operations of the information processing system; and 
         FIG. 7  illustrates an example of a display screen of the terminal device. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     An embodiment will be described below. 
       FIG. 1  illustrates a configuration example of an information processing system according to the embodiment. An information processing system  10  includes users&#39; terminal devices  11 ,  12  and server devices  13 ,  14  that are connected via a network  16  such that the terminal devices  11 ,  12  and the server devices  13 ,  14  can communicate with each other via the network  16 . One or more taxis  15  are connected to the network  16  such that the taxis  15  can communicate via their on-board devices. The terminal devices  11 ,  12  are, for example, mobile phones, smartphones, tablets, or personal computers (PCs). The server devices  13 ,  14  are, for example, server devices that belong to a cloud computing system or other computing system and that implement various functions. The network  16  is, for example, the Internet. The network  16  includes an ad hoc network, a local area network (LAN), a metropolitan area network (MAN), or other network, or any combination thereof. 
     Users (hereinafter respectively referred to as “U 1 ” and “U 2 ”) of the terminal devices  11 ,  12  use a social network service (SNS) service, which is provided by the server device  13 , by executing an SNS application on the terminal devices  11 ,  12 . The server device (hereinafter referred to as the “SNS server device”)  13  mediates transmission and reception of a text messages or an image object between the terminal devices  11 ,  12  using a chat function of the SNS. The users U 1 , U 2  use a taxi dispatch service, which is provided by the server device  14 , by executing a taxi dispatch application on the terminal devices  11 ,  12 . In response to, for example, a request from the terminal device  11 , the server device (hereinafter referred to as the taxi dispatch server device)  14  transmits a command to the taxi  15  to go to the location of the terminal device  11 . 
     The information processing system  10  generally provides the SNS service and the taxi dispatch service to the user U 1  as follows. When the SNS server device  13  mediates transmission and reception of an image object indicating the necessity of dispatching a taxi from the terminal device  11  to the terminal device  12  while the users U 1 , U 2  are chatting on SNS using the terminal devices  11 ,  12 , the SNS server device  13  transmits to the terminal device  11  a dispatch message an offer to dispatch a taxi. When the SNS server device  13  receives an acceptance of the offer from the terminal device  11 , the SNS server device  13  causes the taxi dispatch server device  14  to dispatch the taxi  15  to the location of the terminal device  11 . The SNS server device  13  and the taxi dispatch server device  14  correspond to the “server device” in the present embodiment. 
     The information processing system  10  provides the taxi dispatch service to the user U 1  in response to transmission of an image object in the SNS service between the terminal devices  11 ,  12 . The user U 1  can therefore timely receive the taxi dispatch service even without having to start and operate the taxi dispatch application while using the SNS application on the terminal device  11 . Convenience for the user U 1  is thus improved. 
       FIG. 2  illustrates a configuration example of the terminal device  11 . The terminal device  11  includes a control unit  21 , a storage unit  22 , a communication unit  23 , a positioning unit  24 , an input unit  25 , and an output unit  26 . The terminal device  11  is, for example, a mobile phone, a smartphone, a tablet, or a PC. The following description of the configuration example is similarly applied to the terminal device  12 . 
     The control unit  21  includes one or more processors, one or more dedicated circuits, or a combination thereof. The processor is, for example, a general-purpose processor such as a central processing unit (CPU), or a dedicated processor specialized in specific processing. The dedicated circuit is, for example, a field-programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The control unit  21  performs information processing related to the operations of the terminal device  11  while controlling each unit of the terminal device  11 . 
     The storage unit  22  includes one or more semiconductor memories, one or more magnetic memories, one or more optical memories, or a combination of at least two types of these memories. The semiconductor memory is, for example, a random access memory (RAM) or a read only memory (ROM). The RAM is, for example, a static RAM (SRAM) or a dynamic RAM (DRAM). The ROM is, for example, an electrically erasable programmable ROM (EEPROM). The storage unit  22  functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit  22  stores information that is used for the operations of the terminal device  11  and information obtained by the operations of the terminal device  11 . 
     The communication unit  23  includes one or more communication interfaces. The communication interface is, for example, an interface corresponding to a mobile communication standard such as Long Term Evolution (LTE), 4th generation (4G), or 5th generation (5G), or a LAN interface. The communication unit  23  receives information that is used for the operations of the terminal device  11  and transmits information obtained by the operations of the terminal device  11 . The terminal device  11  is connected to the network  16  by the communication unit  23  via a nearby router device or a nearby base station for mobile communication, and communicates with other devices via the network  16 . 
     The positioning unit  24  includes one or more global navigation satellite system (GNSS) receivers. The GNSS includes, for example, at least one of the Global Positioning System (GPS), the Quasi-Zenith Satellite System (QZSS), the Global Navigation Satellite System (GLONASS), and Galileo. The positioning unit  24  acquires location information of the terminal device  11 . 
     The input unit  25  includes one or more input interfaces. The input interface is, for example, a physical key, a capacitive key, a pointing device, a touch screen provided integrally with a display, or a microphone that receives voice input. The input interfaces may further include a camera that captures an image or an image code, or an IC card reader. The input unit  25  receives an operation to input information that is used for the operations of the terminal device  11 , and transmits the input information to the control unit  21 . 
     The output unit  26  includes one or more output interfaces. The output interface is, for example, an external or built-in display that outputs information as an image or a video, a speaker that outputs information as sound, or a connection interface with an external output device. The display is, for example, a liquid crystal display (LCD) or an organic electroluminescence (EL) display. The output unit  26  outputs information obtained by the operations of the terminal device  11 . 
     The operations of the terminal device  11  are realized as the processor included in the control unit  21  executes a program. The program can be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a magnetic recording device, an optical disc, a magneto-optical recording medium, or a semiconductor memory. The program is distributed in the form of a portable recording medium having the program recorded thereon, such as a digital versatile disc (DVD) or a compact disc (CD)-ROM. The program may be stored in a storage of a server device and may be distributed by transferring the program from the server device to other computers. A part or all of the operations of the terminal device  11  may be performed by the dedicated circuit included in the control unit  21 . 
       FIG. 3  illustrates a configuration example of the SNS server device  13 . The SNS server device  13  includes a control unit  31 , a storage unit  32 , a communication unit  33 , an input unit  35 , and an output unit  36 . The SNS server device  13  is, for example, a server that belongs to a cloud computing system or other computing system and that implements various functions. The following description of the configuration example is similarly applied to the taxi dispatch server device  14 . 
     The control unit  31  includes one or more processors, one or more dedicated circuits, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU, or a dedicated processor specialized in specific processing. The dedicated circuit is, for example, an FPGA or an ASIC. The control unit  31  performs information processing related to the operations of the SNS server device  13  while controlling each unit of the SNS server device  13 . 
     The storage unit  32  includes one or more semiconductor memories, one or more magnetic memories, one or more optical memories, or a combination of at least two types of the memories above. The semiconductor memory is, for example, a RAM or a ROM. The RAM is, for example, an SRAM or a DRAM. The ROM is, for example, an EEPROM. The storage unit  32  functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit  32  stores information that is used for the operations of the SNS server device  13  and information obtained by the operations of the SNS server device  13 . 
     The communication unit  33  includes one or more communication interfaces. The communication interface is, for example, a LAN interface. The communication unit  33  receives information that is used for the operations of the SNS server device  13  and transmits information obtained by the operations of the SNS server device  13 . The SNS server device  13  is connected to the network  16  by the communication unit  33  and communicates with other devices via the network  16 . 
     The input unit  35  includes one or more input interfaces. The input interface is, for example, a physical key, a capacitive key, a pointing device, a touch screen provided integrally with a display, or a microphone that receives voice input. The input interfaces may further include a camera that captures an image or an image code, or an IC card reader. The input unit  35  receives an operation to input information that is used for the operations of the SNS server device  13 , and transmits the input information to the control unit  31 . 
     The output unit  36  includes one or more output interfaces. The output interface is, for example, a display or a speaker. The display is, for example, an LCD or an organic EL display. The output unit  36  outputs information obtained by the operations of the SNS server device  13 . 
     Functions of the SNS server device  13  are realized as the processor included in the control unit  31  executes a control program. The control program is a program that causes a computer to perform the processes of steps included in the operations of the SNS server device  13  such that the computer realizes functions corresponding to the processes of the steps. That is, the control program is a program that causes the computer to function as the SNS server device  13 . A part or all of the functions of the SNS server device  13  may be realized by the dedicated circuit included in the control unit  31 . 
       FIG. 4  illustrates a configuration example of an on-board device  40  that is mounted on the taxi  15 . The on-board device  40  includes a control unit  41 , a storage unit  42 , a communication unit  43 , a positioning unit  44 , an input unit  45 , and an output unit  46 . The on-board device  40  is, for example, a navigation system, a mobile phone, a smartphone, a tablet, or a PC. 
     The control unit  41  includes one or more processors, one or more dedicated circuits, or a combination thereof. The processor is a general-purpose processor such as a CPU, or a dedicated processor specialized in specific processing. The dedicated circuit is, for example, an FPGA or an ASIC. The control unit  41  performs information processing related to the operations of the on-board device  40  while controlling each unit of the on-board device  40 . 
     The storage unit  42  includes one or more semiconductor memories, one or more magnetic memories, one or more optical memories, or a combination of at least two types of the memories above. The semiconductor memory is, for example, a RAM or a ROM. The RAM is, for example, an SRAM or a DRAM. The ROM is, for example, an EEPROM. The storage unit  42  functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit  42  stores information that is used for the operations of the on-board device  40  and information obtained by the operations of the on-board device  40 . 
     The communication unit  43  includes one or more communication interfaces. The communication interface is, for example, an interface corresponding to a mobile communication standard such as LTE,  4 G, or  5 G. The communication unit  43  receives information that is used for the operations of the on-board device  40  and transmits information obtained by the operations of the on-board device  40 . The on-board device  40  is connected to the network  16  by the communication unit  43  via a base station for mobile communication and communicates with other devices via the network  16 . 
     The positioning unit  44  includes one or more GNSS receivers. The GNSS includes, for example, at least one of GPS, QZSS, GLONASS, and Galileo. The positioning unit  44  acquires location information of the taxi  15 . 
     The input unit  45  includes one or more input interfaces. The input interface is, for example, a physical key, a capacitive key, a pointing device, a touch screen provided integrally with a display, or a microphone that receives voice input. The input interfaces may further include a camera that captures an image or an image code, or an IC card reader. The input unit  45  receives an operation to input information that is used for the operations of the on-board device  40 , and transmits the input information to the control unit  41 . 
     The output unit  46  includes one or more output interfaces. The output interface is, for example, a display or a speaker. The display is, for example, an LCD or an organic EL display. The output unit  46  outputs information obtained by the operations of the on-board device  40 . 
     Functions of the on-board device  40  are realized as the processor included in the control unit  41  executes a control program. The control program is a program that causes a computer to perform the processes of steps included in the operations of the on-board device  40  such that the computer realizes functions corresponding to the processes of the steps. That is, the control program is a program that causes the computer to function as the on-board device  40 . A part or all of the functions of the on-board device  40  may be realized by the dedicated circuit included in the control unit  41 . 
     The terminal devices  11 ,  12  and the SNS server device  13  that have the above configuration operate as follows when the user U 1  chats with the user U 2  on SNS. 
     When the user U 1  transmits an instant message to the user U 2 , the control unit  21  of the terminal device  11  receives text input operation by the user U 1  via the input unit  25  and generates an instant message including the input text. When the user U 1  transmits an image object called a sticker etc. to the user U 2 , the control unit  21  of the terminal device  11  receives, via the input unit  25 , an operation by the user U 1  to call image objects and displays available image objects via the output unit  26 . The control unit  21  displays, via the output unit  26 , image objects stored in advance in the storage unit  22  or image objects received from the SNS server device  13  or the taxi dispatch server device  14  via the communication unit  23 , for example. The control unit  21  receives selection of an image object by the user U 1  via the input unit  25 . The control unit  21  then receives a transmission command from the user U 1  via the input unit  25  and transmits the generated instant message or the selected image object to the SNS server device  13  via the communication unit  23 . The control unit  31  of the SNS server device  13  thus receives the instant message or the image object via the communication unit  33 . The control unit  31  then transmits the received instant message or image object to the terminal device  12  of the user U 2  via the communication unit  33 . The control unit  21  of the terminal device  12  thus receives the instant message or the image object via the communication unit  23 . The control unit  21  displays the received instant message or image object via the output unit  26 . When the user U 2  transmits an instant message or an image object to the user U 1 , the terminal device  12  performs the above operations of the terminal device  11 , the terminal device  11  performs the above operations of the terminal device  12 , and the SNS server device  13  transmits the instant message or image object received from the terminal device  12  to the terminal device  11 . 
     In the present embodiment, the SNS server device  13  cooperates with the taxi dispatch server device  14  to transmit to the terminal device  11  a dispatch message including an offer to dispatch a taxi to the user U 1 . When the user U 1  accepts the offer, the terminal device  11  transmits information indicating the acceptance of the offer to the SNS server device  13 . In this case, the control unit  31  of the SNS server device  13  generates the dispatch message and transmits the message to the terminal device  11  of the user U 1  via the communication unit  33 . When the terminal device  11  receives the dispatch message from the SNS server device  13 , the terminal device  11  displays the dispatch message to the user U 1  and receives an input by the user U 1  regarding whether to accept the offer. The control unit  21  receives the input by the user U 1  indicating the acceptance of the offer via the input unit  25  and transmits information indicating the acceptance of the offer to the SNS server device  13  via the communication unit  23 . The control unit  31  of the SNS server device  13  then transmits information regarding the dispatch to the taxi dispatch server device  14  via the communication unit  33 . 
     The control unit  31  of the taxi dispatch server device  14  transmits and receives various types of information necessary for the dispatch to and from the SNS server device  13  and the on-board device  40  of the taxi  15  via the communication unit  33 . The control unit  41  of the on-board device  40  transmits and receives various types of information necessary for the dispatch to and from the taxi dispatch server device  14  via the communication unit  43 . The control unit  41  of the on-board device  40  displays information regarding the dispatch to a driver via the output unit  46  or receives an operation input by the driver via the input unit  45 . 
     When the user U 1  chats with the user U 2  on SNS, the terminal devices  11 ,  12  display instant messages or image objects transmitted therebetween to the users U 1 , U 2  as a chat history. Similarly, when the user U 1  receives and responds to a dispatch message offer an offer to dispatch a taxi, the terminal device  11  displays to the user U 1  the dispatch message and a response by the user U 1  to the dispatch message together with the chat history. In this case, the control unit  21  of the terminal device  11  stores in the storage unit  22  the instant message, image object, dispatch message, and other information that are received from the SNS server device  13 , and also stores in the storage unit  22  the instant message, image object, information indicating an acceptance of the offer, and other information that are transmitted to the SNS server device  13 . The control unit  21  displays the stored instant messages etc. via the output unit  26 . 
     The operation procedure of the terminal device  11  of the user U 1 , the terminal device  12  of the user U 2 , and the SNS server device  13  when cooperating with each other will be described with reference to  FIGS. 5 to 7 . 
       FIG. 5  illustrates a sequence of operations of the terminal device  11  of the user U 1 , the terminal device  12  of the user U 2 , and the SNS server device  13  when cooperating with each other. The procedure in  FIG. 5  is performed when the user U 1  and the user U 2  transmit instant messages to each other to chat on SNS. 
     In step S 500  of  FIG. 5 , the terminal device  11  generates an instant message (denoted by “IM” in  FIG. 5 ) for the user U 2  in response to the operation by the user U 1 . In step S 502 , the terminal device  11  then transmits the instant message to the SNS server device  13 , and the SNS server device  13  receives the instant message from the terminal device  11 . In step S 504 , the SNS server device  13  performs a forwarding process of setting the destination of the instant message addressed to the user U 2  to the terminal device  12 . In step S 506 , the SNS server device  13  transmits the instant message to the terminal device  12 , and the terminal device  12  receives the instant message transmitted from the SNS server device  13 . In step S 508 , the terminal device  12  displays the received instant message to the user U 2 . 
     In step S 510 , the terminal device  12  of the user U 2  generates an instant message for the user U 1  in response to the operation by the user U 2 . In step S 512 , the terminal device  12  transmits the instant message to the SNS server device  13 , and the SNS server device  13  receives the instant message transmitted from the terminal device  12 . In step S 514 , the SNS server device  13  performs a forwarding process of setting the destination of the instant message addressed to the user U 1  to the terminal device  11 . In step S 516 , the SNS server device  13  transmits the instant message to the terminal device  11 , and the terminal device  11  receives the instant message transmitted from the SNS server device  13 . In step S 518 , the terminal device  11  displays the received instant message to the user U 1 . 
       FIG. 7  illustrates an example of the display screen of the terminal device  11 . In steps S 500  to S 518 , an instant message  702  telling “I missed the last train :(” that is transmitted from the terminal device  11  to the terminal device  12 , and an instant message  703  telling “That&#39;s too bad!” that is transmitted from the terminal device  12  to the terminal device  11 , are displayed as a chat history on a display screen  700 . 
     Referring back to  FIG. 5 , in step S 520 , the terminal device  11  receives the operation by the user U 1  to select an image object (denoted by “OB” in  FIG. 5 ). In step S 522 , the terminal device  11  transmits the selected image object to the SNS server device  13 , and the SNS server device  13  receives the image object transmitted from the terminal device  11 . In step S 524 , the SNS server device  13  performs a forwarding process of setting the destination of the image object addressed to the user U 2  to the terminal device  12 . In step S 526 , the SNS server device  13  transmits the image object to the terminal device  12 , and the terminal device  12  receives the image object transmitted from the SNS server device  13 . In step S 528 , the terminal device  12  displays the received image object to the user U 2 . 
     As shown in  FIG. 7 , an image object  704  that is transmitted from the terminal device  11  to the terminal device  12  in steps S 520  to S 528  and that indicates that the user U 1  missed the last train, that is, indicates the necessity of dispatching a taxi, is displayed after the history of the instant messages  702 ,  703  on the display screen  700 . 
     Referring back to  FIG. 5 , in step S 530 , the SNS server device  13  determines whether the image object indicates the necessity of dispatching a taxi. The control unit  31  of the SNS server device  13  stores in advance an image object determined to indicate the necessity of dispatching a taxi in the storage unit  32 . The control unit  31  compares the transmitted image object with the image object stored in the storage unit  32  to determine whether these image objects are different from each other. The control unit  31  thus determines whether the transmitted image object indicates the necessity of dispatching a taxi. 
     The step of determining whether the image object indicates the necessity of dispatching a taxi may be performed before step S 524  or may be performed during steps S 524 , S 526 . 
     In step S 531 , the SNS server device  13  determines whether a dispatch condition regarding either or both of the location of the terminal device  11  and the time when the image object is transmitted is satisfied. On condition that the dispatch condition is satisfied, the SNS server device  13  transmits to the terminal device  11  a dispatch message including an offer the user U 1  to dispatch a taxi in step S 532 . 
     An example of the dispatch condition is that the location of the terminal device  11  is different from an address of the user U 1 . When the location of the terminal device  11  is the same as the address of the user U 1 , it is highly probable that the user U 1  is already home and does not need a taxi even though the user U 1  has transmitted the image object. It can therefore be determined that the dispatch condition is not satisfied. On the other hand, when the location of the terminal device  11  is different from the address of the user U 1 , it is highly probable that the user U 1  needs a taxi to, for example, go home. It can therefore be determined that the dispatch condition is satisfied. For example, the control unit  31  of the SNS server device  13  stores in advance in the storage unit  32  the address of the user U 1  as membership registration information for the SNS service. The control unit  31  compares the location of the terminal device  11 , which is acquired from the terminal device  11  together with the instant message or the image object, with the address of the user U 1  to determine whether the location of the terminal device  11  is different from the address the user U 1 . 
     Another example of the dispatch condition is that movement of the location of the terminal device  11  is different from the manner of movement by a vehicle. When the path or speed, or both, of the movement of the location of the terminal device  11  are the same as a typical path or speed, or both, of the movement by a vehicle, it is highly probable that the user U 1  is already in a taxi and does not need a taxi. It can therefore be determined that the dispatch condition is not satisfied. On the other hand, when the path or speed, or both, of the movement of the location of the terminal device  11  are the different from the typical path or speed, or both, of the movement by a vehicle, it is highly probable that the user U 1  is not in a taxi yet and needs a taxi. It can therefore be determined that the dispatch condition is satisfied. For example, the control unit  31  of the SNS server device  13  obtains the path or speed of the movement of the terminal device  11  from a change in location of the terminal device  11  with time that is acquired from the terminal device  11  together with the instant message or the image object. The control unit  31  compares the path of the movement of the terminal device  11  with a typical path for vehicle traffic (e.g., a freeway and a highway) on a map to determine whether the path of the movement of the terminal device  11  is different from the typical path for vehicle traffic on the map, or determines whether the speed of the movement of the terminal device  11  is within a typical range of the speed of the movement by a vehicle (e.g., 25 to 90 km/h). The SNS server device  13  thus determines whether the dispatch condition is satisfied. 
     A further example of the dispatch condition is that the time when the image object is transmitted is outside the operating hours of public transportation. When the time when the image object is transmitted is not outside the operating hours of public transportation, the user U 1  may be able to use public transportation and it is therefore highly probable that the user U 1  does not need a taxi. It can therefore be determined that the dispatch condition is not satisfied. On the other hand, when the time when the image object is transmitted is outside the operating hours of public transportation, the user U 1  cannot use public transportation and it is therefore highly probable that the user U 1  needs a taxi. It can therefore be determined that the dispatch condition is satisfied. For example, the control unit  31  of the SNS server device  13  checks the time when the image object is transmitted with the operating hours of public transportation stored in advance in the storage unit  32  and determines whether the time when the image object is transmitted is outside the operating hours of public transportation. The public transportation includes, for example, trains and fixed-route buses. 
     As described above, the dispatch message is transmitted on condition that the dispatch condition is satisfied. This improves accuracy in offering to dispatch a taxi when the user U 1  needs a taxi. However, the dispatch message may be transmitted regardless of the dispatch condition. This process is also included in the scope of the present embodiment. 
     When the SNS server device  13  determines that the dispatch condition is satisfied, the SNS server device  13  transmits the dispatch message to the terminal device  11  and the terminal device  11  receives the dispatch message transmitted from the SNS server device  13  in step S 532 . In step S 534 , the terminal device  11  displays the dispatch message to the user U 1 . When the dispatch condition is not satisfied, the SNS server device  13  continues to mediate transmission and reception of a message or an image object between the terminal devices  11 ,  12 . 
     As shown in  FIG. 7 , dispatch messages  706 ,  708  transmitted from the SNS server device  13  to the terminal device  11  in steps S 530  to S 532  are displayed on the display screen  700 . The dispatch message  706  is a system message telling “The dispatch bot has detected your situation.” Displaying such a system message reduces a sense of abruptness to be given to the user U 1 . The dispatch message  708  is an instant message making the user U 1  an offer “Would you like me to arrange a taxi for you?” 
     Referring back to  FIG. 5 , in step S 536 , the terminal device  11  receives the operation by the user U 1  to accept the offer. In step S 538 , the terminal device  11  transmits information indicating the acceptance of the offer to the SNS server device  13 , and the SNS server device  13  receives this information transmitted from the terminal device  11 . The information indicating the acceptance of the offer is, for example, an instant message including any of affirmative words, such as “yes” and “please,” registered in advance in the storage unit  32  of the SNS server device  13 . Alternatively, the dispatch message may have, as choices, objects that can be selected by the operation by the user U 1  and may include information indicating that the user U 1  has selected acceptance from the given choices. The user U 1  may input such information indicating the acceptance of the offer to the input unit  25  by voice input. The information indicating the acceptance of the offer may include the location information of the terminal device  11 . This eliminates the need for the user U 1  to enter the pickup location to the terminal device  11  to transmit the pickup location to the SNS server device  13 . In step S 540 , the SNS server device  13  confirms that the received information indicates acceptance of the offer. For example, the control unit  31  of the SNS server device  13  confirms the acceptance of the offer either by checking the received information with the words registered in advance in the storage unit  32  or based on the choice selected by the user U 1 . The control unit  31  may also acquire the location of the terminal device  11  as the pickup location of the user U 1  and store the acquired location in the storage unit  32 . 
     As shown in  FIG. 7 , an instant message  710  telling “Yes,” that is, indicating the acceptance of the offer, which has been transmitted from the terminal device  11  to the SNS server device  13  in step S 538 , is displayed on the display screen  700 . 
       FIG. 6  illustrates an operation procedure for dispatching a taxi to the user U 1  by the SNS server device  13  in cooperation with the taxi dispatch server device  14 . 
     When the SNS server device  13  confirms the acceptance of the offer in step S 540  of  FIG. 5 , the SNS server device  13  transmits a dispatch request together with the pickup location of the user U 1  stored in the storage unit  32  to the taxi dispatch server device  14  and the taxi dispatch server device  14  receives the pickup location and the dispatch request from the SNS server device  13  in step S 602  of  FIG. 6 . 
     In step S 604 , the taxi dispatch server device  14  generates an operation request corresponding to the received dispatch request and transmits the operation request to the on-board device  40 , and the on-board device  40  receives the operation request transmitted from the taxi dispatch server device  14 . The operation request includes the pickup location of the user U 1 . 
     In step S 606 , the on-board device  40  displays the pickup location included in the received operation request to the driver. The on-board device  40  receives an operation by the driver to answer whether the taxi  15  is available for the operation request, and generates an operation response regarding the availability of the taxi  15 . When the on-board device  40  generates an operation response indicating that the taxi  15  is available, the on-board device  40  transmits the generated operation response to the taxi dispatch server device  14  and the taxi dispatch server device  14  receives the operation response transmitted from the on-board device  40  in step S 608 . 
     In step S 610 , the taxi dispatch server device  14  generates a dispatch response corresponding to the received operation response and transmits the generated dispatch response to the SNS server device  13 , and the SNS server device  13  receives the dispatch response transmitted from the taxi dispatch server device  14 . In this example, the dispatch response indicates that the taxi  15  is available. 
     In step S 612 , the SNS server device  13  generates a dispatch notification corresponding to the received dispatch response and transmits the generated dispatch notification to the terminal device  11  of the user U 1 , and the terminal device  11  receives the dispatch notification from the SNS server device  13 . In this example, the dispatch notification indicates that the taxi  15  is available. During the period from the time the SNS server device  13  transmits the dispatch request to the taxi dispatch server device  14  in step S 602  to the time the terminal device  11  receives the dispatch notification from the SNS server device  13  in step S 612 , the SNS server device  13  may transmit to the terminal device  11  an instant message indicating that a taxi is being arranged and the terminal device  11  may receive this instant message and display the received instant message to the user U 1 . In step S 614 , the terminal device  11  displays the received dispatch notification to the user U 1 . 
     As shown in  FIG. 7 , an instant message  712  indicating that a taxi is being arranged, telling “The dispatch bot is arranging a taxi,” is displayed on the display screen  700  after the history of the instant message  710  indicating the acceptance of the offer. Displaying such an instant message allows the user U 1  to recognize that a taxi is being arranged and thus reduces the stress the user U 1  may feel while waiting. An instant message  714  corresponding to the dispatch notification is displayed after the instant message  712 . The instant message  714  indicates a pickup point and an estimated pickup time, such as “A taxi has been arranged. Pickup point: P1, Pickup time: T1.” This allows the user U 1  to know when and where to expect the taxi to arrive and to take any necessary action. 
     As described above, according to the present embodiment, an offer to dispatch a taxi is made and a taxi is arranged while the user U 1  is chatting with the user U 2 . The user U 1  can thus receive the taxi dispatch service even without having to start and use the taxi dispatch application. Convenience of the taxi dispatch service is thus improved. 
     In the present embodiment, the SNS server device  13  determines whether an image object transmitted by the terminal device  11  is an image object indicating the necessity of dispatching a taxi, based on a transmission manner in which the user U 1  transmits this image object from the terminal device  11  to terminal devices of other users including the user U 2  in past. 
     An example of the transmission manner is that an instant message transmitted or received by the terminal device  11  to or from other terminal device in association with this image object includes a keyword indicating the necessity of dispatching a taxi. Examples of such a keyword include “miss * last train” (* is a wildcard that can be replaced with any character or any string of characters), “late for * last train,” “can&#39;t go home,” and “no * train.” Such keywords can be set as desired. For example, the control unit  31  of the SNS server device  13  searches for keywords stored in advance in the storage unit  32  in the instant message associated with the image object. When the number of keywords detected by the control unit  31  is equal to or greater than a reference value determined as desired, the control unit  31  determines that this image object is an image object indicating the necessity of dispatching a taxi. In this case, the control unit  31  adds, for example, tag information indicating that there is a need to dispatch a taxi to the image object, and stores the image object with the tag information in the storage unit  32 . The control unit  31  compares the image object transmitted from the terminal device  11  with the image object stored in the storage unit  32  to determine whether the image objects are different from each other. The control unit  31  thus determines whether the image object transmitted from the terminal device  11  indicates the necessity of dispatching a taxi. 
     Another example of the past transmission manner that is used to determine that the image object indicates the necessity of dispatching a taxi is that the location of the terminal device  11  when the terminal device  11  transmits the image object in past is different from the address of the user U 1 . In the case where the terminal device  11  has transmitted the image object at the same location as the address of the user U 1 , it can be determined that the terminal device  11  has transmitted this image object when the user U 1  is home and that this image object does not indicate the necessity of dispatching a taxi. On the other hand, in the case where the terminal device  11  has transmitted the image object at a location different from the address of the user U 1 , it can be determined that the user U 1  uses this image object in, for example, a situation where the user U 1  needs a taxi to get home and that this image object indicates the necessity of dispatching a taxi. For example, the control unit  31  of the SNS server device  13  counts the number of times the location of the terminal device  11  when the terminal device  11  transmits the image object in past is different from the address of the user U 1  stored in advance in the storage unit  32 , and stores the count value in the storage unit  32 . When the count value is greater than a reference value determined as desired, the control unit  31  determines that this image object indicates the necessity of dispatching a taxi. In this case, the control unit  31  adds information indicating that there is a need to dispatch a taxi to this image object, and stores the image object with this information in the storage unit  32 . 
     A further example of the past transmission manner that is used to determine that the image object indicates the necessity of dispatching a taxi is that movement of the location of the terminal device  11  when the terminal device  11  has transmitted the image object is different from movement by a vehicle. When the path or speed, or both, of the movement of the location of the terminal device  11  are the same as a typical path or speed, or both, of the movement by a vehicle, it is highly probable that the user U 1  is already in a taxi. It can therefore be determined that the image object transmitted in such a situation does not indicate the necessity of dispatching a taxi. On the other hand, when the path or speed, or both, of the movement of the location of the terminal device  11  are the different from the typical path or speed, or both, of the movement by a vehicle, it is highly probable that the user U 1  is not in a taxi yet and the image object has been transmitted in a situation in which the user U 1  needs a taxi. It can therefore be determined that this image object indicates the necessity of dispatching a taxi. For example, the control unit  31  of the SNS server device  13  obtains the path or speed of the movement of the terminal device  11  from a change in location of the terminal device  11  that is acquired from the terminal device  11  together with the instant message or the image object. The control unit  31  counts the number of times at which the path of the movement of the terminal device  11  is different from a typical path for vehicle traffic on a map or the number of times the speed of the movement of the terminal device  11  is not within a typical range of the speed of the movement by a vehicle, and stores the count value in the storage unit  32 . When the count value is greater than a reference value determined as desired, the control unit  31  determines that this image object indicates the necessity of dispatching a taxi. In this case, the control unit  31  adds information indicating that there is a need to dispatch a taxi to this image object, and stores the image object with this information in the storage unit  32 . 
     A still further example of the past transmission manner that is used to determine that the image object indicates the necessity of dispatching a taxi is that the time when the image object is transmitted is outside the operating hours of public transportation. When the time when the image object is transmitted is not outside the operating hours of public transportation, the user U 1  may be able to use public transportation. It can therefore be determined that there is no need to dispatch a taxi. On the other hand, when the time when the image object is transmitted is outside the operating hours of public transportation, the user U 1  cannot use public transportation. It can therefore be determined that this image object indicates the necessity of dispatching a taxi. For example, the control unit  31  of the SNS server device  13  counts the number of times at which the image object is transmitted outside the operating hours of public transportation stored in the storage unit  32  in advance, and stores the count value in the storage unit  32 . When the count value is greater than a reference value determined as desired, the control unit  31  determines that this image object indicates the necessity of dispatching a taxi. In this case, the control unit  31  adds information indicating that there is a need to dispatch a taxi to this image object, and stores the image object with this information in the storage unit  32 . 
     Alternatively, the control unit  31  may determine that this image object indicates the necessity of dispatching a taxi when the number of times the movement of the location of the terminal device  11  after a predetermined time has elapsed since the image object is transmitted indicates the movement by a vehicle is greater than a predetermined value. In this case, it can be determined that the user U 1  takes a taxi after a certain amount of time has elapsed since the image object is transmitted in a situation where there is a need to dispatch a taxi. In addition to the above, the control unit  31  may determine that the image object indicates the necessity of dispatching a taxi by performing machine learning of various training data associating an instant message associated with the image object, the time when the image object is transmitted, the location of the terminal device  11 , etc. with a taxi ride history. Such training data includes, for example, transmission histories of image objects etc. by many and unspecified users and their taxi ride histories. That is, the control unit  31  can determine the image object indicating the necessity of dispatching a taxi by learning the transmission histories of image objects by many and unspecified users followed by their taxi rides. The necessity of dispatching a taxi that is associated with the image object is not limited to the case where the user misses the last train and may be in case of urgency. Based on the history of the user taking a taxi after transmitting an image object in association with a text message such as “I will be there soon,” the control unit  31  can determine that this image object indicates the necessity of dispatching a taxi. The necessity of dispatching a taxi may be the case where it is difficult to use public transportation such as when the user has a physical problem. Based on the history of the user taking a taxi after transmitting an image object in association with a text message such as “I got hurt” or “I am not feeling well,” the control unit  31  can determine that this image object indicates the necessity of dispatching a taxi. 
     In the present embodiment, the user U 1  acquires an image object from an SNS service provider for a fee or free of charge. For example, the terminal device  11  downloads an image object from the website of an SNS service provided by the SNS server device  13  in response to the operation by the user U 1  and pays for the image object as necessary by electronic payment. In this case, the SNS service provider defines in advance, for example, attributes of image objects and sells the image objects with their attributes added as tag information. In the case where the necessity of dispatching a taxi is defined as a part of the attributes, the control unit  31  of the SNS server device  13  can store in the storage unit  32  in advance the information that the image object indicates the necessity of dispatching a taxi. The control unit  31  can thus determine that the image object indicates the necessity of dispatching a taxi even when the manner in which this image object is used has not been accumulated. 
     In one example of the present embodiment, a taxi dispatch service provider that operates the taxi dispatch server device  14  provides image objects indicating the necessity of dispatching a taxi to the user U 1  for a fee or free of charge. For example, the terminal device  11  downloads an image object from the website of the taxi dispatch service provided by the taxi dispatch server device  14  in response to the operation by the user U 1  and thus acquires the image object free of charge or pays for the image object by electronic payment. When the user U 1  transmits the image object acquired from the taxi dispatch service provider and receives the taxi dispatch service, the user U 1  receives a discount on the taxi fare. For example, when the SNS server device  13  transmits a dispatch request to the taxi dispatch server device  14  (step S 602  in  FIG. 6 ), the SNS server device  13  transmits the image object received from the terminal device  11  to the taxi dispatch server device  14 . The control unit  31  of the taxi dispatch server device  14  checks this image object with, for example, the record of providing image objects to the user U 1 , which is stored in the storage unit  32 , and checks whether the image object provided to the user U 1  is used. When dispatching the taxi  15 , the taxi dispatch server device  14  instructs the on-board device  40  to give the user U 1  a discount on the taxi fare. The discount amount may be determined according to the number of uses of the image object or may be determined for each image object. The taxi dispatch service provider or a taxi service provider can thus carry out their sales promotion activities through providing image objects. 
     The present disclosure is not limited to the above embodiment. For example, a plurality of blocks illustrated in each block diagram may be integrated, or one block may be divided into a plurality of blocks. Instead of performing the plurality of steps in the flowchart in a chronological order according to the description, the steps may be performed in parallel or in a different order either depending on the processing capability of the device that performs the steps or as necessary. Other modifications may be made without departing from the spirit and scope of the present disclosure.