JP2023085014A - Communication system, communication device, control methods thereof, and program - Google Patents

Abstract

To provide a technique for reducing delay in topic generation.SOLUTION: A communication system for distributing a message generated by a distribution device to a communication device owned by a mobile object using a publish/subscribe-type communication method identifies the mobile object to generate identification information on the mobile object, generates a topic based on the identification information, subscribes the communication device to the topic generated based on the identification information on the mobile object in response to receiving a request for subscription registration including information specifying the mobile object from the communication device, and distributes information generated on the topic by the distribution device to the communication device subscribed to the topic.SELECTED DRAWING: Figure 1

Description

The present invention relates to a communication system, a communication device, a control method thereof, and a program.

BACKGROUND ART In recent years, a traffic system has been proposed in which traffic information is obtained using images and sensor information obtained by cameras and sensors installed near a vehicle travel path (Patent Document 1).

On the other hand, application of a publish/subscribe type asynchronous communication method such as ROS (Robot Operating System) or MQTT (Message Queuing Telemetry Transport) is being studied as a communication method between a server and a terminal (Patent Document 2). By using publish/subscribe type asynchronous communication, publishers and subscribers can communicate without being aware of each other. Therefore, it is possible to obtain the advantage that the scalability of the communication system can be ensured and the implementation of communication processing in each terminal can be simplified. Publish/subscribe communication is configured to deliver information through topics where topics are manually configured and where publishers and subscribers are configured.

JP 2007-293563 Patent No. 6402077

Consider a case where road information obtained from a camera or sensor installed on the road is notified to vehicles via a topic by a publish/subscribe type communication method. In order to notify road information by publish/subscribe type communication, it is necessary for both publisher and subscriber devices to hold topic information in advance. That is, if topic information is not shared in advance between a camera or sensor acting as a publisher and a vehicle acting as a subscriber, the road information obtained from the camera or sensor cannot be notified to the vehicle.

In the publish/subscribe type communication method, after a topic is generated, it becomes possible for publishers to generate and distribute information and for subscribers to receive information. That is, when a topic is generated, a publisher can distribute (publish) road information for that topic, and subscribers (for example, vehicles) receive the distributed road information when they are subscribed to that topic. becomes possible. However, if topic generation is delayed, there will be a delay between when road information is required and when road information is actually generated and notified to vehicles, and useful information may not be obtained. There are issues that arise. For example, in a configuration where topics are generated manually, topic generation may be delayed. Also, if the radio wave condition between the subscriber and the broker is poor, the subscriber's subscription registration will be delayed.

On the other hand, if the information published to the topic contains information other than the information required by the subscriber, the processing load for selecting information on the subscriber side increases. There is also the issue of dynamically generating topics specialized for information related to subscribers in order to reduce computational resources of subscribers. As described above, in order to obtain necessary information such as road information using a communication device carried by a mobile object such as a vehicle or a person as a subscriber, a topic is generated at a necessary timing without delay, and the communication is performed. It is desirable that the device is subscribed.

The present invention provides a technique for reducing topic generation delays.

A communication system according to one aspect of the present invention has the following configuration. i.e.
A communication system for distributing a message generated by a distribution device to a communication device owned by a mobile object according to a publish/subscribe type communication method,
identification means for identifying the moving object and generating identification information for the moving object;
generating means for generating topics based on the identification information;
subscribing the communication device to the topic generated based on the identification information of the mobile in response to receiving a request for subscription registration including information identifying the mobile from the communication device; a registration means for live registration;
distribution means for distributing information generated on the topic by the distribution device to the communication devices subscribed to the topic by the registration means.

According to the present invention, topic creation delays are reduced.

1 is a schematic diagram showing a configuration example of a communication system according to this embodiment; FIG. FIG. 2 is a schematic diagram showing another configuration example of the communication system according to the present embodiment; FIG. 3 is a block diagram showing a functional configuration example of a camera (publisher); Block diagram showing a functional configuration example of a relay device (broker) FIG. 2 is a block diagram showing a functional configuration example of a vehicle (subscriber); FIG. 2 is a sequence diagram showing communication procedures of the communication system according to the embodiment; FIG. 2 is a sequence diagram showing communication procedures of the communication system according to the embodiment; FIG. 2 is a sequence diagram showing communication procedures of the communication system according to the embodiment; 4 is a flowchart showing the operation of a camera (publisher); 4 is a flowchart showing the operation of a topic management unit in a relay device (broker); 4 is a flowchart showing the operation of a publish control unit in a relay device (broker); 4 is a flow chart showing the operation of a vehicle (subscriber); The figure which shows an example of the information table which shows the correspondence of a topic name and a vehicle identifier.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a schematic diagram showing a configuration example of a communication system according to this embodiment. A camera 101 is installed to monitor the situation of the intersection and takes an image of the intersection. The camera 101 functions as a publish/subscribe publisher, generates topic-related information from captured images, and transmits the generated information to the topic. Camera 101 is an example of a publisher that generates and distributes information about a topic, and the imaging function and the distribution function may be provided by separate devices. The relay device 102 is a communication device that operates as a broker that relays publish/subscribe communication. A vehicle 103 is a vehicle that travels on the road, and is equipped with a communication device that functions as a subscriber. A wireless base station 104 wirelessly communicates with the camera 101 and the vehicle 103 . Camera 105 has the same function as camera 101 and is installed at the intersection. The information server 106 functions as a publisher to generate and distribute traffic information and the like provided to the vehicle 103 and other vehicles. In FIG. 1 , camera 101 , camera 105 and vehicle 103 can communicate with relay device 102 and information server 106 via radio base station 104 .

FIG. 2 is a schematic diagram showing another configuration example of the communication system according to this embodiment. Cameras 101 and 105 are installed at intersections and have the same functions as in FIG. A vehicle 103 is equipped with a communication device capable of functioning as a subscriber and travels on the road. The relay device 102 in FIG. 2 is a communication device that has a short-range wireless communication function that covers the vicinity of an intersection and that operates as a broker. The cameras 101 and 105 are connected to the relay device 102 by wire. Also, the vehicle 103 and the relay device 102 are connected by short-range wireless communication and configured to be able to communicate with each other.

FIG. 3 is a block diagram showing a functional configuration example of the camera 101 according to this embodiment. In FIG. 3 , a control unit 111 controls operations of the camera 101 . The control unit 111 has, for example, one or more processors (for example, CPU) and memory (ROM, RAM) (not shown), and implements various controls by executing programs stored in the memory. The imaging unit 112 images a subject and generates image data. The communication unit 113 communicates with an external device via radio or wire. The storage unit 114 holds image data generated by the imaging unit 112 and information used by the control unit 111 . The image analysis unit 115 analyzes captured image data to detect a moving object and its identification information, or to detect an event related to a topic. The publishing unit 116 controls information on topics and notifies external devices via the communication unit 113 . The communication unit 113 communicates with the relay device 102 through wireless communication connection (FIG. 1) or wired communication connection (FIG. 2). Note that part of the configuration described above may be implemented by the control unit 111, that is, a CPU that executes a predetermined program stored in a memory. For example, the image analysis unit 115 and the publishing unit 116 may be realized by the control unit 111, may be realized by dedicated hardware, or may be realized by their cooperation.

FIG. 4 is a block diagram showing a functional configuration example of the relay device 102 according to this embodiment. In FIG. 4, the control unit 121 controls the operation of the relay device 102 . The control unit 121 has, for example, one or more processors (for example, CPU) and memory (ROM, RAM) (not shown), and implements various controls by executing programs stored in the memory. The topic management unit 122 generates topics and notifies external devices of the topics via the communication unit 123 . The communication unit 123 communicates with an external device via radio or wire. The communication unit 123 , for example, communicates with the wireless base station 104 through a wired connection, and communicates with the vehicle 103 through a wireless connection. The storage unit 124 holds information used by the control unit 121, the topic management unit 122, and the like. The publish control unit 125 relays and distributes topic information. Note that part of the configuration described above may be implemented by the control unit 121, that is, a CPU that executes a predetermined program stored in a memory. For example, the topic management unit 122 and the publish control unit 125 may be implemented by the control unit 121, by dedicated hardware, or by their cooperation.

FIG. 5 is a block diagram showing a functional configuration example of a communication device (hereinafter simply referred to as vehicle 103) mounted on vehicle 103 according to this embodiment. In FIG. 5 , a control unit 131 controls communication functions of the vehicle 103 . The control unit 131 has, for example, one or more processors (for example, CPU) and memory (ROM, RAM) (not shown), and implements various controls by executing programs stored in the memory. The display unit 132 displays information notified by the topic, information of the control unit 131, and the like. The communication unit 133 performs wireless communication between vehicle equipment of the vehicle 103 and external equipment (for example, the relay device 102). The storage unit 134 holds information received from topics and information displayed on the display unit 132 by the control unit 131 . The subscribe control unit 135 performs subscribe processing for acquiring information from a device serving as a publisher. The position information processing unit 136 detects and holds the position, traveling direction, traveling speed, and the like of the vehicle 103 . A configuration may be adopted in which location information is acquired to determine a topic to be selected, or whether to execute subscribing. A part of the configuration described above may be implemented by the control unit 131, that is, a CPU that executes a predetermined program stored in the memory. For example, the subscription control unit 135 and the position information processing unit 136 may be realized by the control unit 131, may be realized by dedicated hardware, or may be realized by their cooperation.

FIG. 6 is a diagram showing a sequence of communication operations by the communication system of this embodiment. In FIG. 6, when the vehicle 103 runs and enters the imaging range of the camera 101 (the imaging unit 112), the image analysis unit 115 of the camera 101 detects the vehicle 103 as a moving object from the captured image obtained from the imaging unit 112. (F301). Publishing unit 116 transmits vehicle detection information including identification information (vehicle identifier) for identifying vehicle 103 detected by image analysis unit 115 to relay device 102 via communication unit 113 (F302). In addition, in this embodiment, the vehicle 103 is also called "vehicle A". Upon receiving the vehicle detection information, the topic management unit 122 of the relay device 102 determines a topic name for the detected vehicle and generates a topic (F303).

FIG. 13 is a diagram showing an example of an information table showing the correspondence between topic names and vehicle identifiers in this embodiment. The image analysis unit 115 acquires the vehicle number from the license plate image included in the captured image from the imaging unit 112, and uses it as a vehicle identifier to generate and transmit vehicle detection information. The topic management unit 122 generates topics based on vehicle identifiers. In this embodiment, a vehicle number is used as a vehicle identifier, and the topic management unit 122 determines a topic name from the vehicle number according to a predetermined naming rule to generate a topic. At that time, the topic management unit 122 generates an information table in which vehicle numbers and topic names are associated with each other, as shown in FIG. Alternatively, the topic name may be determined from the vehicle number by referring to an information table in which the correspondence between the vehicle number and the topic name is registered in advance. In that case, topics are not generated for vehicle numbers that are not registered in the information table.

The topic management unit 122 sets the generated topic in the publish control unit 125 (F304), and notifies the camera 101 of the generated topic (topic name) (F305). The publishing control unit 125 to which the topic is set can relay the distributed information. That is, the publish control unit 125 transmits the information published to the topic to subscribers who have subscribed to the topic. Also, the camera 101 notified of the topic can publish information using the notified topic. When the image analysis unit 115 of the camera 101 detects an event related to the vehicle 103 from the captured image from the imaging unit 112 (F306), the publishing unit 116 publishes information including a message notifying the detected event (event 1 information). Publishing unit 116 publishes the generated information (event 1 information) to relay device 102 using the topic name notified in F305 regarding vehicle 103 (that is, vehicle A) (F307).

On the other hand, when the communication unit 133 of the vehicle 103 enters the communicable range of the wireless base station 104, it executes wireless connection processing with the wireless base station 104, and communicates with the relay device 102 via the wireless base station 104. becomes (F308). When the wireless connection processing with the relay device 102 is completed, the subscription control unit 135 transmits a request for subscribing to a topic related to the host vehicle (vehicle 103) provided by the relay device 102 (F309). . The request for subscription registration transmitted from the subscription control unit 135 includes information for specifying the vehicle 103, and the publish control unit 125 uses this information to determine the topic to which the vehicle 103 is subscribed. For example, the request for subscription registration includes information on the vehicle number of vehicle 103 . In this case, the publish control unit 125 refers to the information table described with reference to FIG. 13 to determine the topic name from the notified vehicle number, and subscribes to the corresponding topic.

When the subscription registration is completed, the publish control unit 125 of the relay device 102 distributes (publishes) to the vehicle 103 the information received with the topic name related to the vehicle 103 from the camera 101 . For example, if the information related to the vehicle 103 received from the camera 101 before the vehicle 103 is subscribed is stored in the storage unit 114, the information is transmitted to the vehicle 103 (F310). When the image analysis unit 115 detects that an event related to the vehicle 103 has occurred (F311), the publishing unit 116 generates information (event 2 information) including a message notifying the detected event. Then, the publishing unit 116 publishes to the relay device 102 using the topic name notified in F205 (F312). Publish control unit 125 of relay device 102 publishes the notified information to vehicles 103 subscribing to the topic (F313). As indicated by F306 to F307 and F311 to F312, when the topic name of the vehicle 103 is notified to the camera 101, regardless of the subscription status of the vehicle 103, the camera 101 receives event information related to the vehicle 103. to publish.

After that, when the vehicle 103 moves out of the imaging range of the imaging unit 112, the image analysis unit 115 detects that the vehicle 103 is no longer within the imaging range (F314). When the image analysis unit 115 detects that the vehicle 103 is no longer present in the imageable range, the publishing unit 116 notifies the relay device 102 of vehicle non-detection information indicating a non-detection state of the vehicle 103 (F315). . In the relay device 102 that has received the notification that the vehicle 103 has become undetected, the topic management unit 122 requests the publication control unit 125 to cancel the topic related to the vehicle 103 (F316). The publish control unit 125 cancels the setting of the topic specified by this request, and notifies the vehicle 103 subscribed to the topic of cancellation of the subscription (F317). Note that the image analysis unit 115 and the publishing unit 116 of the camera 101 stop generating and distributing information regarding the vehicle 103 after the vehicle 103 becomes non-detected. Alternatively, for example, the topic management unit 122 of the relay device 102 may receive the vehicle non-detection information (F315) and notify the camera 101 of cancellation of the topic. Alternatively, the publishing control unit 125 that receives the unpublishing request (F316) may notify the camera 101 of the unpublishing of the topic. The image analysis unit 115 and the publishing unit 116 of the camera 101 notified of the cancellation of the topic stop generating and distributing information regarding the vehicle 103 corresponding to the topic of which the cancellation was notified.

Note that FIG. 6 shows a configuration in which the camera 101 publishes information via the broker function (the topic management unit 122 and the publish control unit 125) of the relay device 102, but the camera 101 publishes information to the vehicle 103. It may be configured to In this case, the broker function of the relay device 102 is incorporated in the camera 101, which is the publisher, and the relay device 102 having the broker function can be omitted. Also, a part of the functions of the relay device 102, for example, the functions of the topic management unit 122 may be incorporated into the camera 101, which is the publisher. In addition, in the example of FIG. 6, when the camera 101 detects the vehicle 103 as a moving object, the topic is always generated, but the present invention is not limited to this. For example, it may be configured to determine whether or not to generate a topic based on individual information such as the type of mobile object (vehicle or person) and vehicle number. Further, the determination conditions may be programmed in advance or may be changed arbitrarily. In addition, a configuration may be adopted in which an image of a moving object and related information are displayed on a UI to allow an operator or the like to select whether or not to generate a topic.

FIG. 7 is a diagram showing a sequence when a plurality of cameras (camera 101 and camera 105) are arranged at an intersection in this embodiment. Although FIG. 6 shows an example in which one camera 101 is arranged as a publisher, FIG. 7 shows an example in which two cameras 101 and 105 are arranged as publishers. In FIG. 7, when the vehicle 103 travels and enters the imaging range of the camera 101 (imaging unit 112), the image analysis unit 115 detects the vehicle 103 as a moving body (F401). The publishing unit 116 transmits vehicle detection information indicating that the vehicle 103 has been detected to the relay device 102 (F402). Upon receiving the vehicle detection information, the topic management unit 122 of the relay device 102 determines a topic name based on the vehicle identifier included in the vehicle detection information, and generates a topic regarding the vehicle 103 (F403). The topic management unit 122 sets the generated topic in the publication control unit 125 so that information on the topic can be relayed and distributed (F404). Also, the topic management unit 122 notifies the generated topic (topic name) to all communication devices existing as publishers (camera 101 and camera 105 in this example) (F405, F406). The camera 101 and the camera 105 notified of the topic generate information about the vehicle 103 and publish it using the notified topic. In the example of FIG. 7, an event related to the vehicle 103 is detected by the camera 101 (image analysis unit 115) (F407). The publishing unit 116 of the camera 101 generates information including a message notifying the detected event, and publishes the generated information using the notified topic to the relay device 102 (F408).

On the other hand, when the vehicle 103 enters the communicable range of the radio base station 104, the communication unit 133 executes radio connection processing with the radio base station 104 to enable communication with the relay device 102 via the radio base station 104. becomes (F409). When the wireless connection processing is completed, the subscription control unit 135 of the vehicle 103 transmits a request for subscription registration to the topic related to the vehicle 103 to the relay device 102 (F410). When the subscription registration is completed in the same manner as the procedure described above with reference to FIG. Become. The publish control unit 125 transmits to the vehicle 103 any topic information related to the vehicle 103 that has been received and stored before the vehicle 103 is subscribed. In the example of FIG. 10, the information related to the vehicle 103 received from the camera 101 before the vehicle 103 is subscribed is stored in the storage unit 114 (F407, F408). Therefore, the publish control unit 125 transmits this information to the vehicle 103 (F411).

After that (after subscribing), when the camera 101 and the camera 105 detect an event related to the vehicle 103 , they distribute information notifying the event, and the relay device 102 relays this and distributes it to the vehicle 103 . For example, in FIG. 10, the image analysis unit 115 of the camera 105 detects that an event related to the vehicle 103 has occurred (F412). Publishing unit 116 then publishes information including a message notifying the detected event to relay device 102 using the notified topic regarding vehicle 103 (F413). The publish control unit 125 of the relay device 102 transmits the received information to the vehicles 103 subscribing to the topic (F414). Similarly, the image analysis unit 115 of the camera 101 detects that an event related to the vehicle 103 has occurred (F415). Then, the publishing unit 116 of the camera 101 generates information including a message notifying the detected event, and transmits it to the relay device 102 using the notified topic regarding the vehicle 103 (F416). The publish control unit 125 of the relay device 102 transmits the received information to the vehicles 103 subscribing to the topic (F417).

When the image analysis unit 115 of the camera 101 detects that the vehicle 103 has moved out of the imageable range (F418), the publishing unit 116 of the camera 101 notifies the relay device 102 that the vehicle 103 has become undetected. (F419). Similarly, when the image analysis unit 115 of the camera 105 detects that the vehicle 103 has moved out of the imageable range (F420), the publishing unit 116 of the camera 105 relays that the vehicle 103 has become non-detectable. The device 102 is notified (F421). Upon receiving notification (vehicle non-detection information) that the vehicle 103 has become non-detected from both the cameras 101 and 105, the relay device 102 cancels the publication of the topic related to the vehicle 103. FIG. That is, the topic management unit 122 notifies the publication control unit 125 of a request to unsubscribe the vehicle 103 (publishing cancellation request) (F422). Upon receiving this request, the publish control unit 125 notifies the subscribing vehicle 103 of cancellation of the subscription (F423).

Although FIG. 7 shows the sequence in which the vehicle 103 is first detected by the camera 101 and the topic is generated, the topic is similarly generated when the camera 105 detects the vehicle 103 first. Note that a topic may be generated when both the camera 101 and the camera 105 detect the vehicle 103 . Also, FIG. 7 shows an example of canceling the publication for the topic when it is determined that the vehicle 103 is not detected by both the camera 101 and the camera 105. However, when one of the cameras is not detected, the publication is canceled. It may be configured to be released.

FIG. 8 is a diagram illustrating a sequence example of a communication system in which an information server 106 that functions as a publisher that provides predetermined information to subscribers is arranged in addition to the camera 101 that functions as a publisher. The information server 106 provides, for example, guidance information for guiding vehicles, obstacle information, and the like.

In FIG. 8, when the vehicle 103 travels and enters the imaging range of the imaging unit 112 of the camera 101, the image analysis unit 115 detects the vehicle 103 as a moving body (F501). The image analysis unit 115 transmits vehicle detection information including a vehicle identifier for identifying the detected vehicle 103 to the relay device 102 via the communication unit 113 (F502). Upon receiving the vehicle detection information, the topic management unit 122 of the relay device 102 determines a topic name based on the vehicle identifier and generates a topic related to the vehicle 103 (F503). The topic management unit 122 sets the generated topic in the publish control unit 125 (F504), and notifies the camera 101 and the information server 106 of the generated topic (F505, F506). The publishing control unit 125 notified of the topic can relay the information distributed to the topic. Publishers (here, camera 101 and information server 106) notified of the topic can publish information using the notified topic. Based on the held information, the information server 106 generates information (guidance information in this example) related to the topic notified in F505 (F507), and transmits the generated information to the relay device using the topic. 102 (F508). Further, in FIG. 8, an event related to the vehicle 103 is detected by the image analysis unit 115 of the camera 101 (F509). The publishing unit 116 of the camera 101 generates information including a message notifying the detected event, and publishes it to the relay apparatus 102 using the topic notified in F505 (F510).

On the other hand, when vehicle 103 enters the communicable range of radio base station 104 , communication unit 133 of vehicle 103 executes radio connection processing with radio base station 104 and communicates with relay device 102 via radio base station 104 . It becomes possible (F511). When the wireless connection processing is completed, the subscription control unit 135 of the vehicle 103 transmits a subscription request to the topic related to the own vehicle to the relay device 102 (F512). When the vehicle 103 has been subscribed by the procedure described in FIG. 6, the publish control unit 125 of the relay device 102 transmits the information published to the topic related to the vehicle 103 to the vehicle 103 . If information related to vehicle 103 received from information server 106 or camera 101 before vehicle 103 is subscribed is stored in storage unit 114, publish control unit 125 publishes the information to vehicle 103. to send. In the example of FIG. 8, the guidance information received from the information server 106 and the information received from the camera 101 are transmitted to the vehicle 103 (F513, F514). After subscribing, as in FIGS. 6 and 7, every time information about the vehicle 103 is published from the information server 106 or the camera 101, the publish control unit 125 of the relay device 102 transmits the information to the vehicle 103. .

When the vehicle 103 moves and the camera 101 detects that the vehicle 103 is out of the imageable range (F515), it notifies the relay device 102 that the vehicle is not detected (F516). The relay device 102 that has received the notification that the vehicle has become undetected starts unpublishing the topic. That is, the topic management unit 122 notifies the publication control unit 125 of the unsubscribe request for the topic related to the vehicle 103 (F517). The publish control unit 125 cancels the topic setting related to the vehicle 103 and notifies the vehicle 103 of cancellation of the subscription (F518). The publish control unit 125 also notifies the information server 106 that the topic has been canceled (topic cancellation notification, F519), and stops the information server 106 from transmitting information to the topic. If the information handled by the information server 106 is wide-area information, or if it is better to continue the topic and publish the information even if the vehicle 103 moves out of the imaging range of the camera 101, the information server 106 continues to receive the information. It may be configured to allow Note that the topic management unit 122 may notify the vehicle 103 of the cancellation of the topic.

FIG. 9 is a flowchart for explaining the operation of the camera 101 functioning as a publisher in this embodiment. The flowchart of FIG. 9 shows processing executed by the camera 101 or the camera 105 to realize the operations of the camera 101 shown in FIGS. In the camera 101, when a captured image is acquired by the imaging unit 112 (EYS in S601), processing related to the captured image (S602 to S611) is executed. First, the image analysis unit 115 performs image analysis for detecting a moving object from the obtained captured image (S602). In this example, a vehicle is used as the moving object to be detected. The image analysis unit 115 identifies the vehicle from the vehicle type and vehicle number information detected in S602, and determines whether or not a new vehicle has been detected (S603). If a new vehicle is detected (YES in S603), publishing unit 116 generates vehicle detection information including identification information (vehicle identifier) for identifying the vehicle, and transmits the vehicle detection information to relay device 102 (S604). . Further, when the vehicle that has been detected until then is no longer detected as a result of the image analysis in S602 (YES in S605), the publishing unit 116 detects the vehicle including identification information (vehicle identifier) specifying the vehicle that has become undetected. Generate non-detection information. Then, the publishing unit 116 transmits the generated vehicle non-detection information to the relay device 102 (S606). After that, the publishing section 116 cancels the setting of the topic in the publishing section 116 .

If there is a topic set in the publishing unit 116 (YES in S608), the image analysis unit 115 performs image analysis processing on the captured image to detect an event related to the vehicle corresponding to the set topic. (S609). The topic set in the publishing unit 116 is a topic set in S613 and not subject to release in S607. If an event is detected by image analysis processing (YES in S610), publishing unit 116 generates information for notifying the detected event, and publishes information to relay device 102 using the topic set for the related vehicle. (S611). On the other hand, if a new topic is notified (YES in S612) instead of acquiring a captured image (NO in S601), publishing section 116 sets the notified topic in publishing section 116. FIG. Note that the publishing unit 116 determines whether the notified topic is the same as an existing topic, and sets the topic if it determines that the topic is a new topic.

FIG. 10 is a flowchart showing processing by the topic management unit 122 of the relay device 102 according to this embodiment. The flowchart in FIG. 10 shows processing executed by the topic management unit 122 for realizing the operations shown in FIGS. The topic management unit 122 determines whether vehicle detection information has been received from an external device (for example, the camera 101) (S701). If vehicle detection information has been received (YES in S701), topic generation processing of S702 to S704 is executed. In the topic generation process, the topic management unit 122 determines a topic name based on the vehicle identifier included in the vehicle detection information received from the camera 101, and generates a topic corresponding to this (S702). At this time, the topic management unit 122 determines whether the received vehicle detection information is the same as already received vehicle detection information, and generates a topic if it is determined to be new vehicle detection information. The topic management unit 122 performs publishing settings using the topic (topic name) generated in S702 (S703). In the publish settings, the publish function is set so that the publish control unit 125 can distribute information published to the topic generated in S702 to registered subscribers. With this publish setting, the publish control unit 125 can perform relay processing for transmitting information on the topic to subscribers who have subscribed to the topic. Also, the topic management unit 122 notifies the topic generated in S702 to the camera 101 (and/or the camera 105 and the information server 106) functioning as a publisher (S704). Further, when the topic management unit 122 receives vehicle non-detection information from a publisher (for example, the camera 101) (YES in S705), the topic management unit 122 sets the publication related to the vehicle identifier included in the vehicle non-detection information. Release (S706).

FIG. 11 is a flowchart showing processing by the publish control unit 125 of the relay device 102. As shown in FIG. The flowchart of FIG. 11 shows the processing executed by the publish control unit 125 for realizing the operations shown in FIGS. The publishing control unit 125 determines whether or not there is an instruction for publishing settings from the topic management unit 122 (S801). If a publish setting is instructed (YES in S801), the publishing control unit 125 sets the publishing function so that information published on the topic specified by the instruction can be sent to subscribers (S802). Also, when the topic management unit 122 notifies the unpublishing request (YES in S803), the publishing control unit 125 cancels the setting of the topic specified by the notified unpublishing request (S804). Then, the publish control unit 125 notifies the vehicle corresponding to the topic of unsubscribing (S805).

When the publish control unit 125 receives a request for subscription registration from a vehicle (YES in S806), it subscribes the vehicle that sent the request (S807). The request for subscription registration includes information (for example, vehicle number) specifying the vehicle of the transmission source. The publish control unit 125 subscribes the vehicle to the topic corresponding to the identified vehicle. After that, if there is information published to the corresponding topic and stored in the storage unit 124, the publish control unit 125 transmits the information to the vehicle subscribed in S807 (S808).

The publish control unit 125 also determines whether information published to the set topic has been received from an external device (for example, the camera 101 (105) or the information server 106) (S809). If it is determined that the information published to the topic has been received (YES in S809), the publish control unit 125 determines whether the vehicle is subscribed to the topic (S810). If the vehicle is not subscribed to the topic (NO in S810), the publish control unit 125 saves the received information in the storage unit 124 (S811). The saved information is sent at S808 after the vehicle is subscribed. On the other hand, if the vehicle is subscribed to the topic (YES in S810), the publish control unit 125 transmits the information to the vehicle that is subscribed (S812).

FIG. 12 is a flow chart showing processing when the vehicle 103 enters the communicable range of the radio base station 104 in this embodiment. The communication unit 133 of the vehicle 103 establishes wireless communication connection with the wireless base station 104, and then wireless communication connection with the relay device 102 (S901). When wireless communication connection with the relay device 102 is established (YES in S902), the subscription control unit 135 requests subscription registration to the relay device 102 (S903). More specifically, the subscription control unit 135 sends a subscription registration request including the identification information of the own vehicle (for example, vehicle number) to the relay device 102 so that information on topics related to the own vehicle can be received. Send. Upon receiving the subscription registration request, the relay device 102 subscribes the vehicle as described in S807.

After that, the control unit 131 of the vehicle 103 waits for information on the topic (information transmitted in S808 or S812) transmitted from the relay device 102, and receives the information via the communication unit 133 (S904). The control unit 131 presents the information received in S904 to the user via the display unit 132, for example. The control unit 131 maintains the information waiting state until the subscription cancellation notification is received from the relay device 102 (while the determination in S905 is NO). When the subscription cancellation notification is received from the relay device 102 (YES in S905), this processing ends, and the waiting state of information distributed from the relay device 102 is cancelled.

The present invention is not limited to the one embodiment described above, but can be implemented in various modifications and can be applied to various embodiments without departing from the scope of the invention. For example, in the above embodiment, a vehicle is illustrated as a mobile body, but the mobile body is not limited to this. For example, the mobile object may be a person. In this case, the image analysis unit 115 of the camera 101 may identify the person by face recognition, for example, and notify the relay device 102 of the person. The topic management unit 122 generates a topic name based on the person's recognition information, and sets the topic in the publish control unit 125 . In addition, the publish control unit 125 subscribes a mobile phone owned by a person to a topic and distributes information through communication with the mobile phone. In such a communication system, a mobile phone number owned by a person can be used as identification information for identifying the person.

In the above embodiment, the camera 101, which is the publisher, recognizes the moving object by analyzing the captured image acquired by the imaging unit 112, but the present invention is not limited to this. For example, a mobile object (vehicle) may be identified by wireless communication such as that used at ETC (Electronic Toll Collection System) gates.

As described above, according to the embodiment, by transmitting and receiving information via dynamically generated topics between publishers and subscribers, it is possible to notify subscribers of highly relevant information without delay. This makes it possible to realize an information notification system that is more efficient and has less delay than the conventional system. In addition, when a moving vehicle tries to obtain information related to its own vehicle using the publish/subscribe communication method, waiting time occurs for topic generation and subscribing operations, etc., and reception cannot be started promptly. Problem solved.

(Other examples)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.

The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the claims are appended to make public the scope of the invention.

101: camera, 102: relay device, 103: vehicle, 104: wireless base station, 105: camera, 106 traffic information server

Claims (21)

A communication system for distributing a message generated by a distribution device to a communication device owned by a mobile object according to a publish/subscribe type communication method,
identification means for identifying the moving object and generating identification information for the moving object;
generating means for generating topics based on the identification information;
subscribing the communication device to the topic generated based on the identification information of the mobile in response to receiving a request for subscription registration including information identifying the mobile from the communication device; a registration means for live registration;
and distribution means for distributing information generated on the topic by the distribution device to the communication devices subscribed to the topic by the registration means. 2. The communication system according to claim 1, wherein the identifying means detects and identifies the moving object by analyzing an image captured by an imaging device. 3. The communication system according to claim 2, wherein said moving body is a vehicle, and said identification means generates said identification information from an image of a license plate of said vehicle. The method further comprises canceling means for canceling the subscription registration when it is detected by analyzing the image captured by the imaging device that the moving object is no longer within the imageable range. 4. A communication system according to item 2 or 3. 5. The method according to any one of claims 1 to 4, wherein the information generated regarding the topic is information including a message notifying an event related to the moving object detected from an image captured by an imaging device. Communication system as described. further comprising storage means for storing information generated on the topic if the information was obtained before the communication device was subscribed to the topic;
6. The distribution means distributes the information stored in the storage means to the communication device when the communication device is registered as a subscriber. a communication system as described in . A relay device functioning as a broker in a publish/subscribe type communication system, comprising the relay device functioning as the generation means, the registration means, and the distribution means,
7. The communication system according to claim 1, wherein said relay device comprises notification means for notifying said delivery device of the topic generated by said generation means. including another distribution device, separate from the distribution device, that functions as a publisher in a publish/subscribe communication scheme;
8. The communication system according to claim 7, wherein said notifying means further notifies said topic to said another distribution device. including a plurality of said identification means;
2. The communication system according to claim 1, wherein said generating means generates said topic when said mobile object is identified by at least one of said plurality of identifying means. including a plurality of said identification means;
2. The communication system according to claim 1, wherein said generating means generates said topic when said mobile body is identified by all of said plurality of identifying means. on the condition that the moving object cannot be identified by at least one of the plurality of identifying means, or that the moving object cannot be identified by all of the plurality of identifying means; 11. The communication system according to claim 9 or 10, further comprising canceling means for canceling the subscription registration of said communication device by. A communication device that functions as a publisher in a publish/subscribe type communication method,
identification means for generating identification information for identifying the moving object in response to detection of the moving object;
acquisition means for acquiring a topic generated based on the identification information;
generating means for generating information for distribution on the topic;
and transmitting means for transmitting the information generated by the generating means to a relay device functioning as a broker in the communication method. Further comprising notification means for notifying the relay device that the moving body is not detected when the moving body is not detected by the identification means,
13. The communication apparatus according to claim 12, wherein said generating means stops generating information on said topic when said moving body is not detected. 14. The communication device according to claim 12, wherein the acquisition means transmits the identification information to the relay device and receives notification of the topic related to the identification information from the relay device. A communication device that functions as a broker in a publish/subscribe type communication method,
generating means for generating a topic based on mobile identification information received from a first other communication device functioning as a publisher in the communication scheme;
notification means for notifying the topic to the first other communication device;
receiving means for receiving a request for subscription registration via a communication connection with a second other communication device owned by the mobile;
registration means for subscribing the mobile body to the topic in response to the fact that the identification information and the information specifying the mobile body included in the request indicate the same mobile body. communication equipment. A communication device owned by a mobile that functions as a subscriber in a publish/subscribe type communication scheme,
connection means for wireless communication connection with another communication device functioning as a broker in the communication method;
transmitting means for transmitting a request for subscription registration including identification information for identifying the mobile object via the wireless communication connection;
and receiving means for receiving information distributed from the other communication device via the wireless communication connection after the subscription registration. A method of controlling a communication system for distributing a message generated by a distribution device to a communication device owned by a mobile object according to a publish/subscribe type communication method, comprising:
an identification step of identifying the moving object and generating identification information of the moving object;
a generation step of generating a topic based on the identification information;
subscribing the communication device to the topic generated based on the identification information of the mobile in response to receiving a request for subscription registration including information identifying the mobile from the communication device; a registration process for live registration;
and a distribution step of distributing information generated on the topic by the distribution device to the communication devices subscribed to the topic by the registration step. A control method for a communication device functioning as a publisher in a publish/subscribe type communication system, comprising:
an identification step of generating identification information for identifying the moving object in response to detection of the moving object;
an obtaining step of obtaining a topic generated based on the identification information;
a generating step for generating information for distribution on the topic;
and a transmitting step of transmitting the information generated by the generating step to a relay device functioning as a broker in the communication method. A control method for a communication device functioning as a broker in a publish/subscribe type communication system, comprising:
a generation step of generating a topic based on mobile identification information received from a first other communication device functioning as a publisher in the communication scheme;
a notification step of notifying the topic to the first other communication device;
a receiving step of receiving a request for subscription registration via a communication connection with a second other communication device owned by the mobile;
a registration step of subscribing the mobile body to the topic in response to the fact that the identification information and the information specifying the mobile body included in the request indicate the same mobile body. A method of controlling a communication device to A control method for a communication device owned by a mobile unit that functions as a subscriber in a publish/subscribe type communication system, comprising:
a connecting step of wirelessly connecting with another communication device functioning as a broker in the communication method;
a transmitting step of transmitting, via the wireless communication connection, a request for subscription registration including identification information for identifying the mobile unit;
and a receiving step of receiving information distributed from the other communication device via the wireless communication connection after the subscription registration. A program for causing a computer to function as the communication device according to any one of claims 12 to 16.

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