Patent Publication Number: US-2019193659-A1

Title: Accident information collection system, and accident information collection method

Description:
TECHNICAL FIELD 
     The present invention relates to an accident information collection system, a vehicle-mounted device, and an accident information collection method for collecting information on a traffic accident. 
     BACKGROUND ART 
     Storing a video of the periphery of a vehicle and the like when the vehicle encounters a traffic accident is extremely important for a party concerned in the accident or a third party organization to know behavior of the vehicle, a pedestrian, and the like involved in the accident before and after the accident. As a device for storing an accident video, for example, a driving recorder is known for capturing a video ahead of the vehicle with a camera mounted near a rearview mirror in the vehicle, and storing in the storage device the video of a certain period before and after the accident is detected. 
     In recent years, in order to implement advanced driving assistance and automatic driving, examples are increasing of performing sensing of the periphery of the vehicle with a camera. In addition, it is also considered that a device mounted on each vehicle communicates with another vehicle, an information center, or a roadside facility to exchange information. 
     For example, Patent Literature 1 describes an accident information collection system for transmitting accident information including a video of the periphery of a vehicle captured by a vehicle-mounted camera to an information collection center when an abnormality is detected in the vehicle behavior. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2007-293536 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the accident information collection system described in Patent Literature 1, the information collection center collects accident information only from a vehicle having directly encountered a traffic accident. The video included in the accident information is captured in a field of view of the camera included in the vehicle having directly encountered the traffic accident. 
     Therefore, in the accident information collection system described in Patent Literature 1, a video can be obtained from only a limited viewpoint such as the front of the vehicle. In this case, even if an accident occurs in the side or the rear of the vehicle, there is a possibility that the situation of the accident is not captured in the video at all. In addition, when the capturing function of the camera is lost due to the shock of the accident, the video of the periphery of the vehicle cannot be obtained at all. 
     The present invention has been made to solve problems described above, and it is an object to provide an accident information collection system, a vehicle-mounted device, and an accident information collection method capable of collecting videos of various viewpoints of a traffic accident. 
     Solution to Problem 
     An accident information collection system according to the present invention includes a communication unit, a storage unit, and an information processing unit. 
     The communication unit communicates with one or more vehicle-mounted devices for each generating accident information including information indicating a location and a video of an accident having occurred in a vehicle or the periphery of the vehicle. The storage unit stores accident information received from at least one of the vehicle-mounted devices by the communication unit. The information processing unit collects accident information from at least another one of the vehicle-mounted devices existing in a periphery of a site of an accident indicated by the accident information stored in the storage unit, by controlling the communication unit. 
     Advantageous Effects of Invention 
     According to the present invention, since accident information including videos of an accident is collected from a vehicle existing in the periphery of the accident site in addition to a vehicle having directly encountered the accident, videos of various viewpoints of a traffic accident can be collected. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration example of an accident information collection system according to a first embodiment of the present invention. 
         FIG. 2  is a block diagram illustrating a hardware configuration of a vehicle-mounted device in the first embodiment. 
         FIG. 3  is a block diagram illustrating a hardware configuration of an information center device in the first embodiment. 
         FIG. 4  is a flowchart illustrating operation of the vehicle-mounted device in the first embodiment. 
         FIG. 5  is a diagram illustrating an example of accident information in the first embodiment. 
         FIG. 6  is a flowchart illustrating operation of the information center device in the first embodiment. 
         FIG. 7  is a flowchart illustrating operation of an information center device according to a second embodiment of the present invention. 
         FIG. 8  is a diagram illustrating a relationship between an accident site and a vehicle traveling in the periphery of the accident site. 
         FIG. 9  is a diagram illustrating an overview of generation of a fixed point monitoring video. 
         FIG. 10  is a diagram illustrating an example of accident information in a third embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, in order to explain the present invention in more detail, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. 
     First Embodiment 
       FIG. 1  is a block diagram illustrating a functional configuration of an accident information collection system  1  according to a first embodiment of the present invention. In addition,  FIG. 2  is a block diagram illustrating a hardware configuration of a vehicle-mounted device  2 .  FIG. 3  is a block diagram illustrating a hardware configuration of an information center device  3 . 
     The accident information collection system  1  includes the vehicle-mounted device  2  mounted on a vehicle, and the information center device  3  for collecting accident information transmitted from the vehicle-mounted device  2 . 
     The vehicle-mounted device  2  detects an accident having occurred in the vehicle or the periphery of the vehicle, and transmits the accident information on the accident to the information center device  3 . Note that, the accident information is information including location information and a video of the accident having occurred in the vehicle or the periphery of the vehicle. 
     In addition, in the example illustrated in  FIG. 1 , the vehicle-mounted device  2  and the information center device  3  are connected together by a network  5  via a radio base station  4 . 
     Note that, the vehicle-mounted device  2  and the information center device  3  may be communicatively connected together by inter-vehicle communication via a vehicle-mounted communication device, or may be communicatively connected together via a communication device installed on the roadside. 
     The vehicle-mounted device  2  includes a communication unit  20 , an information acquisition unit  21 , an accident detection unit  22 , and a storage unit  23 . 
     The communication unit  20  communicates with the information center device  3  via the radio base station  4  and the network  5 . For example, the communication unit  20  transmits the accident information to the information center device  3  in accordance with control from the accident detection unit  22 . In addition, when a transmission instruction of the accident information is received from the information center device  3 , the communication unit  20  returns the accident information to the information center device  3  regardless of the control from the accident detection unit  22 . At this time, the communication unit  20  stores the accident information in the storage unit  23 . 
     The information acquisition unit  21  acquires information on a vehicle state and a situation of the periphery of the vehicle. For example, the information is acquired from a vehicle-mounted camera, an acceleration sensor, a global positioning system (GPS) receiver, a vehicle control device, and the like. The vehicle-mounted camera captures a video of the periphery of the vehicle. The acceleration sensor detects acceleration in the front-back direction generated in the vehicle. The GPS receiver analyzes GPS information received from GPS satellites and detects the time information and the location information of the vehicle. In addition, the information acquisition unit  21  acquires driving operation information such as a vehicle speed, a steering angle, and brake information from the vehicle control device. 
     On the basis of the information acquired by the information acquisition unit  21 , the accident detection unit  22  detects the accident having occurred in the vehicle or the periphery of the vehicle. For example, the accident detection unit  22  determines that the accident has occurred in the vehicle when the acceleration or the brake state exceeds a threshold value, and determines that the accident has occurred in the periphery of the vehicle from an analysis result of the video of the periphery of the vehicle. In addition, the accident detection unit  22  generates accident information on the accident having occurred in the vehicle or the periphery of the vehicle. When the accident information is generated, the accident detection unit  22  instructs a communication unit  30  to transmit the accident information to the information center device  3 . 
     The storage unit  23  stores the accident information generated by the accident detection unit  22 . 
     The communication unit  20  in the vehicle-mounted device  2  communicates using a communication terminal  102  illustrated in  FIG. 2 , and the storage unit  23  stores the information in a storage medium  104  illustrated in  FIG. 2 . In addition, the information acquisition unit  21  acquires information from a sensor group  100 . That is, the sensor group  100  includes the vehicle-mounted camera, the acceleration sensor, the GPS receiver, and the vehicle control device described above. 
     In addition, individual functions of the communication unit  20 , the information acquisition unit  21 , the accident detection unit  22 , and the storage unit  23  in the vehicle-mounted device  2  are implemented by a processing circuit. That is, the vehicle-mounted device  2  includes a processing circuit for communicating with the information center device  3 , acquiring the information on the vehicle state and the situation of the periphery of the vehicle, performing detection of the accident having occurred in the vehicle or the periphery of the vehicle and generation of accident information, and instructing transmission of the accident information to the information center device  3 . The processing circuit may be dedicated hardware, or a processor  101  for executing a program stored in a memory  103 . 
     When the processing circuit is the dedicated hardware, examples of the processing circuit include a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and a combination thereof. The functions of the communication unit  20 , the information acquisition unit  21 , the accident detection unit  22 , and the storage unit  23  may be implemented by respective processing circuits, or the functions of the units may be collectively implemented by a processing circuit. 
     When the processing circuit is the processor  101 , the functions of the communication unit  20 , the information acquisition unit  21 , the accident detection unit  22 , and the storage unit  23  are implemented by software, firmware, or a combination of software and firmware. The software or the firmware is described as the program and stored in the memory  103 . The processing circuit reads and executes the program stored in the memory  103 , thereby implementing the function of each of the units. 
     That is, the vehicle-mounted device  2  includes the memory  103  for storing a program that when executed by the processing circuit, resultantly executes a series of processing steps of acquiring the information on the vehicle state and the situation of the periphery of the vehicle, performing detection of the accident having occurred in the vehicle or the periphery of the vehicle and generation of accident information, on the basis of the information, and transmitting the accident information to the information center device  3 . 
     In addition, examples of the memory  103  include a nonvolatile or volatile semiconductor memory such as a random access memory (RAM), a read only memory (ROM), a flash memory, an erasable programmable ROM (EPRROM), or an electrically erasable programmable ROM (EEPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a digital versatile disc (DVD), and the like. 
     Note that, the functions of the communication unit  20 , the information acquisition unit  21 , the accident detection unit  22 , and the storage unit  23  may be partially implemented by the dedicated hardware and partially implemented by the software or the firmware. For example, for the communication unit  20 , its function can be implemented by a processing circuit as the dedicated hardware, and for the information acquisition unit  21 , the accident detection unit  22 , and the storage unit  23 , a processing circuit can implement their functions by reading and executing the program stored in the memory  103 . 
     As described above, the processing circuit can implement the above-described functions by the hardware, software, firmware, or a combination thereof. 
     The information center device  3  includes the communication unit  30 , a storage unit  31 , and an information processing unit  32 . 
     The communication unit  30  communicates with the vehicle-mounted device  2 . For example, the communication unit  30  communicatively connects to the network  5  and communicates with the communication unit  20  of the vehicle-mounted device  2  via the radio base station  4 . 
     The storage unit  31  sequentially stores pieces of accident information received from one or more of the vehicle-mounted device  2  by the communication unit  30 . 
     Note that, the accident information stored in the storage unit  31  can be read by the information processing unit  32  as appropriate. 
     The information processing unit  32  determines an accident for which accident information needs to be further collected, from among accidents indicated by pieces of accident information stored in the storage unit  31 . For example, when an accident situation or an accident site included in accident information matches a predetermined condition, the corresponding accident is determined as a serious accident for which accident information needs to be further collected. Examples of the predetermined condition include whether an accident site is on an expressway, whether there is overturning or falling of a vehicle, whether a number of vehicles are involved, and whether a pedestrian or a two-wheeled vehicle is involved. 
     In addition, the information processing unit  32  instructs a vehicle-mounted device  2  existing in the periphery of the site of the accident determined to be the one for which accident information needs to be collected, to transmit accident information, by controlling the communication unit  30 . 
     For example, the information processing unit  32  controls the communication unit  30  to perform simultaneous distribution of a transmission request of accident information to a communication range including the periphery of the accident site. When the transmission request of accident information is received, a vehicle-mounted device  2  determines whether or not the vehicle-mounted device  2  exists in the periphery of the accident site, on the basis of location information of the accident site included in the transmission request. Then, when existing in the periphery of the accident site, the vehicle-mounted device  2  generates and transmits accident information on the accident to the information center device  3 . 
     Note that, in addition to transmitting the accident information, the information processing unit  32  may instruct the storage unit  23  included in the vehicle-mounted device  2  to store the accident information. 
     The communication unit  30  in the information center device  3  communicates using a communication terminal  201  illustrated in  FIG. 3 , and the storage unit  31  stores the information in a storage medium  203  illustrated in  FIG. 3 . 
     In addition, individual functions of the communication unit  30 , the storage unit  31 , and the information processing unit  32  in the information center device  3  are implemented by a processing circuit. 
     That is, the information center device  3  includes a processing circuit for receiving accident information by communicating with the vehicle-mounted device  2 , storing the accident information received from the vehicle-mounted device  2 , and collecting accident information from a vehicle-mounted device  2  existing in the periphery of the site of the accident indicated by the accident information stored. 
     The processing circuit may be dedicated hardware, or a processor  200  for executing a program stored in a memory  202 . 
     When the processing circuit is the dedicated hardware, examples of the processing circuit include a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC, an FPGA, and a combination thereof. The functions of the communication unit  30 , the storage unit  31 , and the information processing unit  32  may be implemented by respective processing circuits, or the functions of the units may be collectively implemented by a processing circuit. 
     When the processing circuit is the processor  200 , the functions of the communication unit  30 , the storage unit  31 , and the information processing unit  32  are implemented by software, firmware, or a combination of software and firmware. The software or the firmware is described as the program and stored in the memory  202 . The processing circuit reads and executes the program stored in the memory  202 , thereby implementing the function of each of the units. 
     That is, the information center device  3  includes the memory  202  for storing a program that when executed by the processing circuit, resultantly executes a series of processing steps of receiving accident information by communicating with the vehicle-mounted device  2 , storing the accident information received from the vehicle-mounted device  2 , and collecting accident information from a vehicle-mounted device  2  existing in the periphery of the site of the accident indicated by the accident information stored in the storage unit  31 , by controlling the communication unit  30 . In addition, the memory  202  is similar to the memory  103  described above. 
     Note that, the functions of the communication unit  30 , the storage unit  31 , and the information processing unit  32  may be partially implemented by the dedicated hardware and partially implemented by the software or the firmware. For example, for the communication unit  30 , its function can be implemented by a processing circuit as the dedicated hardware, and for the storage unit  31  and the information processing unit  32 , a processing circuit can implement their functions by reading and executing the program stored in the memory  202 . 
     As described above, the processing circuit can implement the above-described functions by the hardware, software, firmware, or a combination thereof. 
     Next, the operation will be described. 
       FIG. 4  is a flowchart illustrating the operation of the vehicle-mounted device  2 , and illustrates a series of processing steps of detecting an accident in the vehicle or the periphery of the vehicle and transmitting the corresponding accident information to the information center device  3 . 
     First, the information acquisition unit  21  continuously acquires information on the vehicle state and the situation of the periphery of the vehicle from the sensor group  100  at certain intervals, such as 30 times per second. The information is successively output from the information acquisition unit  21  to the accident detection unit  22 . 
     The accident detection unit  22  determines an abnormality in the acceleration of the vehicle acquired by the information acquisition unit  21  (step ST 1 ). For example, when the acceleration applied in the front-back direction of the vehicle exceeds a predetermined threshold value, it is determined that the vehicle has encountered an accident and thus acceleration that cannot be generated in normal driving has been generated. 
     When it is determined that there is no abnormality in the acceleration of the vehicle (step ST 2 ; NO), the accident detection unit  22  determines whether or not there is an abnormality in a brake state of the vehicle acquired by the information acquisition unit  21  (step ST 3 ). For example, when the brake strength exceeds a predetermined threshold value, it is determined that the vehicle has encountered an accident and thus a sudden braking maneuver that cannot be performed in normal driving has been performed. 
     On the other hand, when it is determined that there is an abnormality in the acceleration of the vehicle (step ST 2 ; YES) or when it is determined that there is an abnormality in the brake state of the vehicle (step ST 4 ; YES), the accident detection unit  22  determines that the vehicle has encountered an accident (step ST 5 ). 
     When it is determined that there is no abnormality in the brake state of the vehicle (step ST 4 : NO), the accident detection unit  22  determines whether or not there is an abnormality in the periphery of the vehicle from the video of the periphery of the vehicle acquired by the information acquisition unit  21  (step ST 6 ). 
     As a method of determining whether or not there is an abnormality from the video of the periphery of the vehicle, for example, it is conceivable to use machine learning. In the machine learning, a discriminator is provided that has learned videos of accidents each of which has occurred in the periphery of a vehicle. The accident detection unit  22  inputs the video of the periphery of the vehicle to the discriminator, and the discriminator discriminates whether or not an accident occurs in the video. The discriminator is stored in the memory  103 . 
     In addition, a discriminator may be used that has learned videos each of which shows that no abnormality has occurred in the periphery of a vehicle. 
     When it is determined that there is no abnormality in the periphery of the vehicle (step ST 7 ; NO), the processing is ended. 
     On the other hand, when it is determined that there is an abnormality in the periphery of the vehicle (step ST 7 ; YES), the accident detection unit  22  determines that a peripheral vehicle has encountered an accident (step ST 8 ). 
     When it is determined that the vehicle has encountered an accident in step ST 5 , or when it is determined that the peripheral vehicle has encountered an accident in step ST 8 , the accident detection unit  22  generates accident information on the accident, and instructs the communication unit  20  to transmit the accident information to the information center device  3 . The communication unit  20  transmits the accident information to the information center device  3  in accordance with the instruction of the accident detection unit  22 . 
     Further, the accident detection unit  22  instructs the storage unit  23  to store the accident information. As a result, the storage unit  23  stores the accident information generated by the accident detection unit  22 . 
     The processing so far corresponds to step ST 9 . Note that, when the vehicle-mounted device  2  does not include the storage unit  23 , the accident detection unit  22  performs only an instruction to the communication unit  20  in step ST 9 . 
     In the example of  FIG. 4 , the case has been described where the acceleration generated in the vehicle and the brake state are sequentially determined; however, it is not always necessary to make the determination in this order. In addition, it may be determined whether the vehicle has encountered an accident from acceleration, a sudden change in the vehicle speed other than in the brake state, activation of the airbag, a sudden change in the steering angle, or the like. 
     In addition, in  FIG. 4 , the case has been described where whether or not there is an abnormality in the periphery of the vehicle is determined after it is determined whether or not the vehicle has encountered an accident; however, this is not a limitation. 
     That is, the processing of determining whether or not there is an abnormality in the periphery of the vehicle and the processing of determining whether or not the vehicle has encountered an accident may be executed in parallel with each other. 
       FIG. 5  is a diagram illustrating an example of accident information  10  in the first embodiment. The accident detection unit  22  generates the accident information  10  on an accident having occurred in the vehicle or the periphery of the vehicle from the information acquired by the information acquisition unit  21 . Here, as illustrated in  FIG. 5 , the accident information  10  includes, for example, vehicle information  10   a , an accident situation  10   b , date and time information  10   c , location information  10   d , steering information  10   e , brake information  10   f , acceleration information  10   g , vehicle speed information  10   h , sensor information  10   i , driver information  10   j , log information  10   k , and a video  10   l.    
     The vehicle information  10   a  is information for specifying a vehicle on which the vehicle-mounted device  2  is mounted, and is, for example, license plate information of the vehicle, or a unique ID allocated to the vehicle or the vehicle-mounted device  2 . 
     The accident situation  10   b  is information indicating whether the vehicle has encountered an accident or the peripheral vehicle has encountered an accident. In addition, a detailed situation of the accident is also included, such as whether there is overturning or falling of a vehicle, whether a number of vehicles are involved, or whether a pedestrian or a two-wheeled vehicle is involved. 
     The date and time information  10   c  indicates the date and time when the accident information  10  has been transmitted to the information center device  3  or the date and time when the accident has been encountered. In addition, it may be the date and time when the accident information  10  has been stored in the storage unit  23 . Further, when the accident information  10  is continuously generated within a certain period and is stored in the storage unit  23 , the storage start date and time and the storage end date and time may be included in the date and time information  10   c.    
     The location information  10   d  is information indicating a location (latitude and longitude, or the like) of a place where the accident information  10  is transmitted to the information center device  3 , and is information indispensable for the accident information  10 . Note that, the location information  10   d  may be a location of a place where the storage unit  23  has stored the accident information  10 . 
     The information center device  3  specifies a location of the accident site from the location information  10   d.    
     The steering information  10   e  is information indicating a change in the steering angle of the steering wheel, and is acquired continuously for a certain period by the information acquisition unit  21 . The steering information  10   e  includes, for example, information at the time when the accident has occurred and information before and after the accident. In addition, the brake information  10   f  is information indicating the brake state (brake strength), and is acquired continuously for a certain period by the information acquisition unit  21 . The brake information  10   f  includes, for example, information at the time when the accident has occurred and information before and after the accident. 
     The acceleration information  10   g  is information indicating the acceleration generated in the vehicle, and is acquired continuously for a certain period by the information acquisition unit  21 . The acceleration information  10   g  includes, for example, information at the time when the accident has occurred and information before and after the accident. The vehicle speed information  10   h  is information indicating the speed of the vehicle, and is acquired continuously for a certain period by the information acquisition unit  21 . The vehicle speed information  10   h  includes, for example, information at the time when the accident has occurred and information before and after the accident. 
     The sensor information  10   i  is information indicating the specifications and the mounting positions in the vehicle of the sensors mounted on the vehicle, that is, the sensor group  100 . For example, information such as the specification and the mounting position of the camera is included. In addition, the driver information  10   j  is information indicating a state and personal information of a driver of the vehicle. The state of the driver is a biological state of the driver, and includes, for example, the direction of the face, the heart rate, and the like. The state of the driver is a result obtained by the sensor group  100  sensing the driver continuously for a certain period. In addition, the personal information of the driver includes, for example, the sex and age of the driver. 
     The log information  10   k  is information indicating a detection log of the sensor group  100  mounted in the vehicle. The log information  10   k  includes, for example, information at the time when the accident has occurred and information before and after the accident. 
     The video  10   l  is a video of the periphery of the vehicle captured by the camera mounted on the vehicle in the sensor group  100 , and is information indispensable for the accident information  10 . The video of the camera is acquired continuously for a certain period by the information acquisition unit  21 , and the video  10   l  includes information at the time when the accident has occurred and information before and after the accident. For example, the video  10   l  is a video for 1 minute in which a video for 30 seconds from immediately before the accident to the occurrence of the accident and a video for 30 seconds after the occurrence of the accident are combined together. 
       FIG. 6  is a flowchart illustrating the operation of the information center device  3 , and illustrates a series of processing steps of receiving accident information from the vehicle-mounted device  2  and further collecting accident information from a vehicle-mounted device  2  existing in the periphery of the accident site. 
     First, while the information center device  3  is activated, the communication unit  30  always accepts accident information from the vehicle-mounted device  2 . That is, if accident information is not received (step ST 1   a ; NO), the processing of step ST 1   a  is repeated. 
     When accident information is received from the vehicle-mounted device  2  (step ST 1   a ; YES), the communication unit  30  outputs the accident information to the storage unit  31 . The storage unit  31  stores the accident information received by the communication unit  30  (step ST 2   a ). For example, the accident information is stored in the storage medium  203 . 
     Next, the information processing unit  32  analyzes pieces of accident information stored in the storage unit  31 , and determines an accident for which accident information needs to be further collected, from among accidents indicated by the pieces of accident information stored in the storage unit  31  (Step ST 3   a ). 
     For example, the information processing unit  32  specifies the location of the accident site from the location information  10   d  included in the accident information  10 , and performs image analysis of the video  10   l  to specify the accident situation. Then, when the accident site or the accident situation matches a predetermined condition, the information processing unit  32  determines that the corresponding accident is a serious accident for which accident information needs to be further collected. As described above, examples of the predetermined condition include whether an accident site is on an expressway, whether there is overturning or falling of a vehicle, whether a number of vehicles are involved, and whether a pedestrian or a two-wheeled vehicle is involved. 
     Here, when accident information does not need to be further collected (step ST 4   a ; NO), the processing is ended. In addition, when it is determined that accident information needs to be further collected (step ST 4   a ; YES), the information processing unit  32  instructs a vehicle-mounted device  2  existing in the periphery of the accident site to transmit accident information by controlling the communication unit  30  (step ST 5   a ). 
     For example, the information processing unit  32  generates a transmission request for accident information, the transmission request including a site location of the accident for which accident information needs to be further collected and information requesting accident information on the accident. 
     Then, the information processing unit  32  instructs the communication unit  30  to perform simultaneous distribution of the transmission request of accident information to a communication range including the site location of the accident. 
     As a result, on the basis of the location information of the accident site included in the transmission request, a vehicle-mounted device  2  determines whether or not the vehicle-mounted device  2  is in the periphery of the accident site. When existing in the periphery of the accident site, the vehicle-mounted device  2  generates and transmits accident information on the accident to the information center device  3 . 
     Note that, in addition to transmitting the accident information, the information processing unit  32  may instruct the storage unit  23  included in the vehicle-mounted device  2  to store the accident information. 
     As described above, in the accident information collection system  1  according to the first embodiment, the information center device  3  collects accident information from a vehicle existing in the periphery of the accident site in addition to a vehicle having directly encountered the accident. As a result, videos of various viewpoints of a traffic accident can be collected. 
     In addition, since accident videos of various viewpoints can be obtained as accident information, a party concerned or a third party organization can accurately grasp the accident situation. 
     Further, since accident information on an accident encountered by a peripheral vehicle is also collected, even when the vehicle-mounted device  2  is not mounted on the peripheral vehicle, accident information can be collected from a vehicle existing in the periphery of the accident site. 
     In addition, in the accident information collection system  1  according to the first embodiment, the communication unit  30  of the information center device  3  receives from the vehicle-mounted device  2  the accident information  10  which further includes, in addition to the location information  10   d  and the video  10   l , at least one of the vehicle information  10   a , the accident situation  10   b , the date and time information  10   c , the steering information  10   e , the brake information  10   f , the acceleration information  10   g , the vehicle speed information  10   h , the sensor information  10   i , the driver information  10   j , and the log information  10   k.    
     As a result, in addition to the location information and the video of the accident site, information can also be obtained on the vehicle and the periphery of the vehicle, the sensor, and the driving state, so that the party concerned or the third party organization can accurately grasp the information on the accident. 
     Further, in the accident information collection system  1  according to the first embodiment, the accident detection unit  22  of the vehicle-mounted device  2  detects occurrence of an accident in the periphery of the vehicle, on the basis of the video in which the periphery of the vehicle is captured. As a result, even when the camera is not mounted on a vehicle having directly encountered the accident, the vehicle-mounted device  2  existing in the periphery of the vehicle can detect the accident of the vehicle. Since the accident information obtained in this way is transmitted from the vehicle-mounted device  2  to the information center device  3 , the accident information can be surely collected. 
     Second Embodiment 
     In an accident information collection system according to a second embodiment, an information center device generates a video in which an accident site is captured from a certain direction, on the basis of videos of the same accident included in a respective plurality of pieces of accident information stored in a storage unit. That is, a pseudo fixed point monitoring video can be obtained. 
     A vehicle-mounted device and the information center device in the second embodiment are similar to the configuration illustrated in  FIG. 1 , but are different therefrom in that an information processing unit of the information center device generates the fixed point monitoring video. 
     Therefore, hereinafter, a configuration of the vehicle-mounted device and the information center device in the second embodiment will be described with reference to  FIG. 1 . 
     Next, the operation will be described. 
       FIG. 7  is a flowchart illustrating the operation of the information center device  3  in the second embodiment, and illustrates a series of processing steps of receiving pieces of accident information from respective vehicle-mounted devices  2  and generating a pseudo fixed point monitoring video of an accident site. Note that, since the processing from step ST 1   a  to step ST 5   a  in  FIG. 7  is the same as that in  FIG. 6 , the description will be omitted. 
     In addition,  FIG. 8  is a diagram illustrating a relationship between an accident site and a vehicle traveling in the periphery of the accident site.  FIG. 9  is a diagram illustrating an overview of generation of the fixed point monitoring video. 
     In step ST 6   a , the information processing unit  32  generates a pseudo fixed point monitoring video on the basis of videos of the same accident included in a respective plurality of pieces of accident information stored in the storage unit  31 . 
     As illustrated in  FIG. 8 , as an example, a case will be described where, at a point A located in the periphery of a site of an accident caused by a vehicle  300  and a vehicle  301 , a vehicle  302  arrives at time t 1 , a vehicle  303  arrives at time t 2  later than the time t 1 , and a vehicle  304  arrives at time t 3  later than the time t 2 . 
     The vehicle-mounted device  2  mounted on each of the vehicle  302 , the vehicle  303 , and the vehicle  304  detects the accident. At this time, as illustrated in  FIG. 9 , the vehicle-mounted device  2  mounted on the vehicle  302  generates accident information including a video  400  of the accident and location information of the point A, and transmits the accident information to the information center device  3 . 
     Next, the vehicle-mounted device  2  mounted on the vehicle  303  generates accident information including a video  401  of the accident and the location information of the point A, and transmits the accident information to the information center device  3 . Further, the vehicle-mounted device  2  mounted on the vehicle  304  generates accident information including a video  402  of the accident and the location information of the point A, and transmits the accident information to the information center device  3 . Note that, the vehicle-mounted device  2  mounted on another vehicle arriving at the point A after the vehicle  304  having passed through the point A also similarly transmits accident information to the information center device  3 . 
     The information processing unit  32  of the information center device  3  extracts a frame image  400   a  at the time t 1  when the vehicle  302  arrives at the point A, from the video  400  included in the corresponding accident information received by the communication unit  30 . Next, similarly, the information processing unit  32  extracts a frame image  401   a  at the time t 2  when the vehicle  303  arrives at the point A, from the video  401 , and extracts a frame image  402   a  at the time t 3  when the vehicle  304  arrives at the point A, from the video  402 . The information processing unit  32  repeats the same processing for videos from other vehicles arriving at the point A following the vehicle  304 . 
     In this way, the information processing unit  32  sequentially acquires the frame images of the accident site captured at the point A. By arranging the frame images in chronological order, a pseudo fixed point monitoring video  500  can be obtained. 
     However, a time interval between the frame images in the fixed point monitoring video  500  varies depending on a positional relationship between the corresponding vehicles. In addition, depending on the mounting position of the camera in the vehicle and the specification of the camera, a position and a size of a subject, an image characteristic, and the like in the frame image may vary. 
     For this reason, simply arranging the frame images extracted as described above in chronological order may result in an unnatural video even when the frame images of the fixed point monitoring video are continuously reproduced. 
     Therefore, the information processing unit  32  corrects the frame images extracted as described above to obtain a natural video when the frame images of the fixed point monitoring video are continuously reproduced. 
     For example, the information processing unit  32  specifies the mounting position and specification of the camera from the sensor information  10   i  included in each accident information  10 , and thus corrects differences in position and size of the corresponding subject and a difference in image characteristic between the frame images. In addition, correction may be performed by matching feature points with each other between the frame images so that a positional relationship between the feature points becomes appropriate. 
     Further, a frame image at missing time may be interpolated by correcting one frame image or by synthesizing a plurality of frame images so that the time intervals of the frame images become uniform. 
     In addition, in the vehicle-mounted devices  2  mounted on a respective plurality of vehicles, capturing ranges of respective cameras are often different from each other. 
     Therefore, the information processing unit  32  may extract frame images for each same time from a respective plurality of accident information videos, and spatially connect the frame images together to sequentially synthesize frame images. By performing such so-called panorama synthesis, a video is generated indicating the accident site in a wider range than the video captured by the camera of each vehicle. 
     As described above, in the accident information collection system  1  according to the second embodiment, the information processing unit  32  generates a video indicating the accident temporally or spatially continuously, on the basis of the videos of the same accident included in the respective plurality of pieces of accident information stored in the storage unit  31 . 
     By generating the video indicating the accident temporally continuously in this way, a video can be provided in which fixed point monitoring of the accident site is performed continuously for a certain period. As a result, the party concerned and the third party organization can accurately grasp changes over time at the accident site. 
     In addition, by generating the video indicating the accident spatially continuously, a video can be provided in which the accident site is panoramically captured. As a result, the party concerned and the third party organization can accurately grasp the situation of the accident site. 
     Third Embodiment 
     A vehicle-mounted device and an information center device in a third embodiment are similar to the configuration illustrated in  FIG. 1 , but are different therefrom in that the vehicle-mounted device and the information center device exchange a hash value. 
     Therefore, hereinafter, a configuration of the vehicle-mounted device and the information center device in the third embodiment will be described with reference to  FIG. 1 . 
     The hash value is a value obtained by performing arithmetic processing of a hash function on target data. 
     As hash functions, functions such as SHA-1, SHA-2, and MD5 are known. The data size of the hash value is much smaller than that of the target data. In addition, hash values obtained from the same target data by arithmetic operation with the same hash function are the same value, and when hash functions or pieces of target data are different from each other, hash values obtained thereby are also different values. 
     By using this feature, it is possible to confirm whether or not accident information has been tampered with when the accident information is transmitted and received. 
       FIG. 10  is a diagram illustrating an example of accident information  10 A in the third embodiment of the present invention. In the accident information  10 A illustrated in  FIG. 10 , the video  10   l  of the accident information  10  illustrated in  FIG. 5  is replaced by a video hash  10   m.    
     The video hash  10   m  is a value obtained by performing arithmetic processing of the hash function on video data of an accident. Note that, hash values may be generated from, in addition to the video data, one or more pieces of information among the multiple pieces of information constituting the accident information  10 A illustrated in  FIG. 10 . 
     When an accident having occurred in the vehicle or the periphery of the vehicle is detected, the vehicle-mounted device  2  generates a hash value from the video data of the accident, for example, and transmits the hash value as accident information to the information center device  3 . For example, when a vehicle on which the vehicle-mounted device  2  is mounted encounters an accident, there is a possibility that the communication unit  20  malfunctions due to an impact of the accident or the like, and thereby an amount of information that can be communicated is reduced. Even in this case, the hash value having a small data size can be accurately transmitted to the information center device  3 . 
     After the hash value is transmitted, the vehicle-mounted device  2  transmits raw data of the accident information to the information center device  3  with reception of a transmission request from the police or the like as a trigger. 
     The information processing unit  32  of the information center device  3  generates a hash value from the accident information received later and compares the hash value with the previously received hash value to confirm whether or not both hash values coincide with each other. As a result, it is possible to confirm whether or not the accident information has been tampered with. 
     As described above, in the accident information collection system  1  according to the third embodiment, the communication unit  20  of the vehicle-mounted device  2  generates a hash value from the accident information and transmits the hash value as accident information to the information center device  3 . Since only the hash value of the accident information is transmitted as described above, the communication load of the accident information is greatly reduced as compared with a case where the video itself is transmitted, and transmission failure of the accident information can be reduced. 
     The communication unit  30  of the information center device  3  receives the hash value generated from the accident information by the vehicle-mounted device  2 . The information processing unit  32  determines whether or not the accident information has been tampered with, on the basis of a result of comparing the hash value received by the communication unit  30  with the hash value generated from the accident information received by the communication unit  30 . As a result, it is possible to ensure admissibility of evidence of the accident video. 
     Note that, in the present invention, within the scope of the invention, free combination of the embodiments, a modification of any component of each embodiment, or omission of any component in each embodiment is possible. 
     INDUSTRIAL APPLICABILITY 
     Since the accident information collection system according to the present invention can collect videos of various viewpoints of a traffic accident, it is suitable for an emergency notification system for making an emergency call on the basis of accident information. 
     REFERENCE SIGNS LIST 
     
         
           1  Accident information collection system 
           2  Vehicle-mounted device 
           3  Information center device 
           4  Radio base station 
           5  Network 
           10 ,  10 A Accident information 
           10   a  Vehicle information 
           10   b  Accident situation 
           10   c  Date and time information 
           10   d  Location information 
           10   e  Steering information 
           10   f  Brake information 
           10   g  Acceleration information 
           10   h  Vehicle speed information 
           10   i  Sensor information 
           10   j  Driver information 
           10   k  Log information 
           10   l  Video 
           10   m  Video hash 
           20 ,  30  Communication unit 
           21  Information acquisition unit 
           22  Accident detection unit 
           23 ,  31  Storage unit 
           32  Information processing unit 
           100  Sensor group 
           101 ,  200  Processor 
           102 ,  201  Communication terminal 
           103 ,  202  Memory 
           104 ,  203  Storage medium 
           300  to  304  Vehicle 
           400  to  402  Video 
           400   a  to  402   a  Frame image 
           500  Fixed point monitoring video.