JP5310461B2 - Inter-vehicle information communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-vehicle information communication device capable of reducing the communication load or storage capacity, while maintaining information fresh. <P>SOLUTION: The inter-vehicle information communication device that performs vehicle-to-vehicle communication includes a transmission/reception control unit 10 capable of transmitting and receiving information; an expiration date calculating unit 12, that calculates an expiration date defining a period during which the information received by control of the transmitting/receiving control unit 10 or the information that a vehicle 3 has is handled as information; and an integral operation process unit 11 that generates integrated information, by integrating a plurality of pieces of information regarding the same event, from among the information that the vehicle 3 has, or a plurality of pieces of information received from the other vehicle. The integral operation process unit 11 calculates the expiration date of the integrated information, according to the time the plurality of pieces of information from which the integrated information is generated were obtained, the time the integrated information was generated, or the expiration date. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an inter-vehicle information communication device.

  2. Description of the Related Art Conventionally, as an apparatus for communicating information between vehicles, a device used for ad hoc communication in which information held by each vehicle is directly transmitted and received between vehicles by inter-vehicle communication is known (for example, see Patent Document 1). In the system having the inter-vehicle communication device described in Patent Document 1, the server sets an expiration date in an ad hoc ID that can uniquely identify a vehicle to be transmitted and received, and distributes the ad hoc ID to the information. Include and communicate. As a result, it is possible to avoid tracking a specific vehicle beyond the expiration date from the acquired information.

JP 2006-174179 A

  By the way, the information transmitted from other vehicles by the ad hoc communication described in Patent Document 1 includes, for example, information related to the same event such as link time information. For this reason, from the viewpoint of reducing communication load and recording capacity, information on the host vehicle and information on the same event received from other vehicles are integrated by general statistical calculation processing such as average values, and the integrated information is handled. A method can be considered.

  However, when integrating a plurality of pieces of information with expiration dates set by statistical calculation processing, there is a possibility that old information whose expiration date has expired is included in the integrated information after a predetermined period after integration. And even if some of the original information of the integrated information has expired, it is not possible to separate only the expired information from the integrated information, The freshness of information may be reduced.

  Accordingly, the present invention has been made to solve such a technical problem, and provides an inter-vehicle information communication device capable of reducing a communication load or a storage capacity while maintaining freshness of information. Objective.

  That is, the vehicle-to-vehicle information communication device according to the present invention is a vehicle-to-vehicle information communication device that performs vehicle-to-vehicle communication, and has communication means capable of transmitting and receiving information and the information received by the communication means, or the host vehicle. Of the information, an expiration date calculating means for calculating an expiration date that defines a period to be handled as information, the information received from another vehicle and the information that the host vehicle has, or a plurality of the information received from another vehicle A statistical processing unit that integrates a plurality of pieces of information related to the same event to generate integrated information, and the expiration date calculating unit includes an acquisition time, a generation time, or a generation time of the plurality of pieces of information that are the sources of the integrated information The expiration date of the integrated information is calculated based on the expiration date.

  In the inter-vehicle information communication apparatus according to the present invention, integrated information obtained by integrating information related to the same event is generated by the statistical processing unit, and the acquisition time and generation time of a plurality of pieces of information that are sources of the integrated information are generated by the expiration date calculating unit. Alternatively, the expiration date of the integrated information is calculated based on the expiration date. In this way, it is possible to reflect the expiration date of a plurality of information that is the source of integrated information, or the acquisition time or generation time necessary for appropriately determining the expiration date of each information in the expiration date of the integrated information. It is possible to appropriately calculate the expiration date of the integrated information. Therefore, the freshness of information can be maintained, and communication load or storage capacity can be reduced by performing communication or recording using integrated information, for example.

  Here, the communication unit may transmit the information or the integrated information based on the expiration date. With this configuration, it is possible to reduce the communication load while maintaining the freshness of information.

  In addition, the information or the integrated information may be recorded in association with the expiration date. With this configuration, it is possible to reduce the storage capacity while maintaining the freshness of information.

  The expiration date calculating means preferably employs at least one of a transmission expiration date that defines a period during which the information can be transmitted and an expiration date that defines a period during which the vehicle can use the information as the expiration date. is there.

  By configuring in this way, it is possible to distinguish between the time limit for transmission to another vehicle and the time limit for use in the own vehicle for one piece of information, so use in the own vehicle while maintaining the freshness of the information to be transmitted. Can be secured.

  Further, the expiration date calculating unit may calculate the transmission time limit to be shorter than the usage time limit when the transmission time limit and the usage time limit are adopted as the expiration date. By comprising in this way, it can avoid transmitting the information immediately before becoming unusable to another vehicle.

  According to the present invention, communication load or storage capacity can be reduced while maintaining freshness of information.

It is a block diagram which shows the structure of a vehicle provided with the information communication apparatus between vehicles which concerns on embodiment. It is a flowchart which shows the reception operation | movement of the information communication apparatus between vehicles shown in FIG. It is a flowchart which shows the transmission operation | movement of the information communication apparatus between vehicles shown in FIG. It is a schematic diagram for demonstrating operation | movement of the information communication apparatus between vehicles which concerns on 1st Embodiment. It is a schematic diagram for demonstrating operation | movement of the information communication apparatus between vehicles which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating operation | movement of the conventional inter-vehicle information communication apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

(First embodiment)
The inter-vehicle information communication apparatus according to the present embodiment is preferably employed when, for example, information observed by other vehicles and information observed by the host vehicle are shared by inter-vehicle communication.

  First, a vehicle including the inter-vehicle information communication device according to the present embodiment will be described. FIG. 1 is a schematic diagram illustrating a configuration of a vehicle 3 including an inter-vehicle information communication device 1 according to the embodiment. As shown in FIG. 1, the vehicle 3 includes a communication device 30, an ECU (Electronic Control Unit) 2, and a data DB 31. The ECU is a computer of an electronically controlled automobile device, and includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input / output interface.

  The communication device 30 has a function of transmitting / receiving information to / from other vehicles by inter-vehicle communication. The communication device 30 is connected to the ECU 2 and has a function of outputting information received from the other vehicle to the ECU 2 and a function of transmitting information input from the ECU 2 to the other vehicle. The information transmitted / received to / from other vehicles includes the generation time of the information. The information generation time is set by the vehicle that generated the information.

  The data DB 31 is a database in which information is stored, and is configured to be referred to and written from the ECU 2. The data DB 31 stores information received by the communication device 30, information calculated by the ECU 2, information acquired from a sensor (not shown) provided in the vehicle 3, and the like. Further, the data DB 31 may be configured so that it can be referred to not only from the ECU 2 but also from other control units other than the ECU 2.

  The information stored in the data DB 31 is associated with the generation time of the information (life origin) and the expiration date (life) that defines the period to be handled as information. Information within the expiration date is handled as valid data, and information whose expiration date has passed is handled as invalid data. Note that the information stored in the data DB 31 may be further associated with a section indicating the content of the information.

  The ECU 2 includes a transmission / reception control unit 10, an integrated calculation processing unit 11, an expiration date calculation unit 12, and a recording processing unit 13. The transmission / reception control unit 10, the integrated calculation processing unit 11, the expiration date calculation unit 12, and the recording processing unit 13 constitute the inter-vehicle information communication device 1.

  The transmission / reception control unit 10 has a function of controlling transmission / reception of the communication device 30. First, the transmission function of the transmission / reception control unit 10 will be described. For example, the transmission / reception control unit 10 has a function of inputting information to be transmitted with reference to the data DB 31, a generation time of the information, and an expiration date. The transmission / reception control unit 10 has a function of determining whether or not the expiration date of the information to be transmitted has expired. The transmission / reception control unit 10 performs predetermined processing such as signal conversion processing necessary for communication on the information within the expiration date and the generation time of the information, and then outputs the processed information to the communication device 30. Thus, it has a function of transmitting to a predetermined destination. Next, the reception function of the transmission / reception control unit 10 will be described. The transmission / reception control unit 10 has a function of inputting information and a generation time of the information from the communication device 30, performing predetermined processing such as signal conversion, and then outputting the information to the expiration date calculation unit 12.

  The integrated arithmetic processing unit 11 has a function of integrating information related to the same event and generating new information. Here, the information related to the same event includes, for example, time (link travel time) required to pass a certain link, road environment information, traffic information, weather information, vehicle control information, and the like. The integrated arithmetic processing unit 11 may determine whether the information is related to the same event with reference to the content of the information, or the information stored in the data DB 31 is associated with a classification indicating the content of the information. If it is, it may be determined whether the information is related to the same event using the classification. The integrated calculation processing unit 11 has a function of performing an integrated calculation process such as an average value, a median value, and a mode value on a plurality of pieces of information related to the same event, and outputting the integrated information. The integrated arithmetic processing unit 11 may execute the integrated arithmetic processing at a predetermined timing, or may execute the integrated arithmetic processing at a timing when new information is stored in the data DB 31. Further, the integrated arithmetic processing unit 11 has a function of outputting the generated integrated information to the expiration date calculating unit 12.

  The expiration date calculation unit 12 has a function of calculating the expiration date of information. The expiration date calculation unit 12 is connected to the transmission / reception control unit 10 and the integrated calculation processing unit 11 and calculates the expiration date of the information output by the transmission / reception control unit 10 or the integrated information output by the integration calculation processing unit 11. have. For example, for the information output from the transmission / reception control unit 10 (that is, received information), the expiration date calculation unit 12 calculates the time after the elapse of a predetermined period (lifetime period) based on the generation time of the information as the expiration date. It has a function to do. That is, the expiration date calculation unit 12 has a function of calculating the expiration date of information by adopting the generation time of the information as the origin time of the expiration date (life origin). On the other hand, the expiration date calculation unit 12 has a function of calculating the expiration date based on the generation time of the original information regarding the integrated information output by the integration calculation processing unit 11. For example, the expiration date calculation unit 12 has a function of calculating a generation time of integrated information by performing a weighted average of generation times of information to be integrated using an information amount of information to be integrated. The expiration date calculation unit 12 has a function of adopting the generation time calculated by the weighted average as the origin time of the expiration date (life origin) and setting the time after a predetermined period (life time period) as the expiration date. ing. In addition, the expiration date calculation unit 12 inputs information from, for example, sensors (not shown), adopts the information generation time as the origin time (life origin) of the expiration date, and validates the time after a predetermined period (life period) has elapsed. It has a function to set as a time limit. In addition, the lifetime used by the expiration date calculation unit 12 may be changed for each information or may be a constant value. The expiration date calculation unit 12 has a function of outputting information and the expiration date of the information to the recording processing unit 13.

  The recording processing unit 13 has a function of storing information in the data DB 31. For example, the recording processing unit 13 has a function of associating the expiration date of the information output by the expiration date calculation unit 12 with the information output by the expiration date calculation unit 12 and storing the information in the data DB 31. In addition, the recording processing unit 13 may have a function of deleting information that is a source of the integrated information from the data DB 31 when storing the integrated information in the data DB 31. Moreover, you may have a function which deletes the information which expired among the information which exists in data DB31.

  Next, the transmission / reception operation of the inter-vehicle information communication device 1 according to the present embodiment will be described. First, the reception operation of the inter-vehicle information communication device 1 will be described. FIG. 2 is a flowchart showing the receiving operation of the inter-vehicle information communication device 1. The control process shown in FIG. 2 is executed, for example, at a timing when the vehicle 3 receives information from another vehicle.

  As shown in FIG. 2, the inter-vehicle information communication device 1 starts from a received data input process (S10). The process of S <b> 10 is a process executed by the transmission / reception control unit 10 and receiving the reception data and the generation time of the reception data from the communication device 30. When the process of S10 ends, the process proceeds to an expiration date setting process (S12).

The process of S12 is a process that is executed by the expiration date calculation unit 12 and calculates the expiration date of the received data acquired in the process of S10. For example, the expiration date calculation unit 12 calculates the expiration date of the reception data based on the generation time of the reception data. Details of this processing will be described with reference to FIG. FIG. 4 is a schematic diagram for explaining the operation of the inter-vehicle information communication device 1. In FIG. 4, the lifetime of information is displayed with the horizontal axis as the time axis. FIG. 4 shows the information generation time t _S , information amount S, and expiration date t _T together with the information name. Here, it is assumed that the vehicle 3 has the information A with a life period T of 5 seconds and an information amount of 1 before the processing of FIG. For convenience of explanation, the generation time t _S of the holding information A is set to 0. In addition, it is assumed that the information B is generated in the other vehicle when the time t = 2. Thus, in the case of having information A, describing the process of setting an expiration date t _T to the information B received in the processing of S10. As shown in FIG. 4, it is assumed that the information B and its generation time t _S are received from another vehicle when the time Now ₁ = 2.5. In this case, the expiration date calculating unit 12 calculates the expiration date t _T of the information B by adding the predetermined lifetime T with the generation time t _S = 2 of the information B as the lifetime origin. Note that the lifetime T may be variable for each piece of information, but here, the lifetimes of the information A and the information B are assumed to be the same in consideration of ease of explanation. That is, the expiration date calculation unit 12 calculates the expiration date t _T = 7 of the reception information B by adding the lifetime T = 5 to the generation time t _S = 2 of the information B. When the process of S12 is completed, the process proceeds to a recording process (S14).

The process of S14 is a process executed by the recording processing unit 13 to record information in association with the expiration date and generation time of the information. For example, the recording processing unit 13 associates the information input in the process of S10 with the expiration date and the generation time calculated in the process of S12 and stores them in the data DB 31. For example, the information B shown in FIG. 4 is associated with the expiration date t _T and the generation time t _S and stored in the data DB 31. When the process of S14 ends, the process proceeds to the same event determination process (S16).

  The process of S16 is a process executed by the integrated arithmetic processing unit 11 to determine whether or not information on the same event as the received data exists. For example, the integrated arithmetic processing unit 11 refers to the data DB 31 and determines whether information on the same event as the received data is stored. For example, the integrated arithmetic processing unit 11 may check the content of the received data and determine whether or not there is information on the same event by comparing with the content of the information stored in the data DB 31. The contents of the data may be confirmed and categorized according to a predetermined classification, and compared with the information classification stored in the data DB 31, it may be determined whether or not information on the same event exists. If it is not determined in step S16 that the same event information as the received data exists, the control process shown in FIG. On the other hand, in the process of S16, when it is determined that the same event information as the received data exists, the process proceeds to the integration process (S18).

The process of S18 is a process executed by the integrated arithmetic processing unit 11 to integrate a plurality of pieces of information of the same event. For example, the integrated arithmetic processing unit 11 performs statistical processing based on a plurality of pieces of information on the same event, and outputs integrated information such as an average value. This process will be described with reference to FIG. The retained information A (information amount S = 1) and the received information B (information amount S = 3) shown in FIG. 4 are information of the same event, and the retained information A and the received information B are integrated to generate integrated information C. It shall be. Amount of information S _A holdings information _A, if the information amount of the received information B and S _B, the amount of information S _C of the integrated information C can be expressed by the following equation.

The integrated calculation processing unit 11 calculates the information amount SC of the integrated information _C as 1 + 3 = 4 using Expression 1. When the process of S18 ends, the process proceeds to an expiration date calculation process (S20).

The process of S20 is a process executed by the expiration date calculation unit 12 to calculate the expiration date of the integrated data. For example, the expiration date calculation unit 12 calculates the expiration date of the integrated data based on the generation time of the data that is the source of the integrated data. Details of this processing will be described with reference to FIG. In the process of S18, the holding information A (information amount S = 1, generation time t _S = 0) and reception information B (information amount S = 3, generation time t _S = 2) shown in FIG. 4 are integrated and integrated. Assume that information C is generated. If the information amount of the retained information A is S _A , the generation time is t _SA , the information amount of the reception information B is S _B , and the generation time is t _SB , the generation time t _SC of the integrated information C can be expressed by the following equation. it can.

Expiration calculation unit 12, using Equation 2 to calculate the 1.5 generation time _{t SC} of integrated information C. Then, the calculated generation time t _SC and life origin, calculates the expiration date t _T of integrated information C by adding the predetermined lifetime T. The lifetime T may be variable for each piece of information, but here is set to a constant 5 in consideration of ease of understanding. In other words, the expiration date calculating unit 12 calculates the expiration date t _T = 6.5 of the integrated information C by adding the lifetime T = 5 to the generation time t _SC = 1.5 of the integrated information C. When the process of S20 ends, the process proceeds to a recording process (S22).

The process of S22 is a process executed by the recording processing unit 13 to record the integrated information and the expiration date of the integrated information in association with each other. Recording processing unit 13, for example, in association with the expiration date t _T calculated in the process of generating the integrated information C and in S20 the process of S18 is recorded in the data DB 31. It should be noted that a category indicating the content of information may be further associated and recorded. Further, the information that becomes the integration source may be deleted from the data DB 31. When the process of S22 ends, the control process shown in FIG. 2 ends.

The control process shown in FIG. By executing the control process shown in FIG. 2, when the vehicle 3 has the same event information as the information received from another vehicle, the received information and the held information are integrated and integrated. Information is generated and the expiration date of the integrated information is calculated and recorded. Moreover, it is also possible to further integrate the generated integrated information and the received information by repeatedly executing the control process shown in FIG. For example, as shown in FIG. 4, when the time Now ₂ = 6 after generating the integrated information C, the information is the same event information as the integrated information C, the information amount S = 5, and the generation time t _S = 5. Is received. Since the expiration date t _T of the integrated information C is 6.5, it is valid at the time Now ₂ = 6. Therefore, based on the information amount of the integrated information C and the reception information D, the integrated information E with the information amount S = 9 is generated using Equation 1, and based on the information amount and the generation time of the integrated information C and the reception information D. Using the expression 2, the generation time of the integrated information E is calculated as 3.4, and the expiration date t _T of the integrated information E is calculated as 8.4.

Here, in order to compare and explain the effect of the inter-vehicle information communication device 1 according to the present embodiment, an example in which the generation time of the integrated information is the reception time (acquisition time) of the information that is the source of the integrated information. Will be described with reference to FIG. In FIG. 6, similarly to FIG. 4, the lifetime of information is displayed with the horizontal axis as the time axis, and the generation time t _S , information amount S, and expiration date t _T of the information are shown together with the information name. As shown in FIG. 6, the lifetime T is set to a constant value 5. Then, it is assumed that the vehicle 3 has the information A with the information amount S = 1 and the expiration date t _T = 5, and has received the information B with the information amount S = 3 at the time t = 2.5. In this case, the information amount S of the integrated information C is 1 + 3 = 4, and the generation time t _S of the integrated information C is the reception time t of the information B = 2.5. That is, the integrated information C has an information amount S = 4 and an expiration date t _T = 7.5. Thereafter, at time t = 6, it is assumed that information D having the same amount of information as the integrated information C and having an information amount S = 5 is received. Since the expiration date t _T of the integrated information C is 7.5, it is valid at the time t = 6. For this reason, the information amounts of the integrated information C and the reception information D are added to generate the integrated information E with the information amount S = 9, and the reception time t = 6 of the reception information D is set as the generation time t _S of the integrated information E. The expiration date t _T of the integrated information E is calculated as 11. Thus, assuming that the reception time of information is the generation time of integrated information, as long as new information is continuously received from other vehicles, the old information that has expired continues to be extended, and the old information is also included in the integrated information. It becomes the state included.

  On the other hand, according to the vehicle-to-vehicle information communication device 1 according to the present embodiment, as shown in FIG. Therefore, the generation time of the integrated information can be advanced compared to the case where the reception time of the information that is the source of the integrated information is used. That is, regarding the integrated information, it is possible to set a time that goes back from the origin of the lifetime, so that even if the lifetime is constant, the expiration date can be set ahead. For example, in FIG. 4, when the reception time of the information B that is the source of the integrated information C is t = 2.5, the life origin of the integrated information C is set to a time (t = 1.5) that goes back from the present time. be able to. As a result, even if information is newly received from another vehicle, the service life origin gradually goes back and the service life will eventually come. Therefore, it is possible to avoid a situation in which information is extended forever. In this way, even when information is integrated and compressed, an appropriate expiration date can be set, which can contribute to the reduction of the storage area.

  Next, the transmission operation of the inter-vehicle information communication device 1 will be described. FIG. 3 is a flowchart showing the transmission operation of the inter-vehicle information communication device 1. The control process shown in FIG. 3 may be repeatedly executed at a predetermined interval from a predetermined timing, for example, or may be executed at a timing when the vehicle 3 receives a transmission request from another vehicle.

  As illustrated in FIG. 3, the inter-vehicle information communication device 1 starts from a transmission data input process (S30). The process of S30 is a process executed by the transmission / reception control unit 10 to input transmission data from the data DB 31. When the process of S10 ends, the process proceeds to an expiration date determination process (S32).

  The process of S32 is a process executed by the transmission / reception control unit 10 to determine whether or not the expiration date of the transmission data input in the process of S30 has expired. The transmission / reception control unit 10 refers to the data DB 31 and determines whether or not the expiration date of the transmission data has passed. If it is determined in S32 that the expiration date has passed, the control process shown in FIG. 3 is terminated. On the other hand, in the process of S32, when it is determined that it is within the expiration date, the process proceeds to the transmission process (S34).

  The process of S34 is a process executed by the transmission / reception control unit 10 and outputting the transmission data input in the process of S30 to the communication device 30. Through this process, the communication device 30 transmits the transmission data to the destination other vehicle. When the process of S34 ends, the control process shown in FIG. 3 ends.

  Thus, the control process shown in FIG. 3 is finished. By executing the control process shown in FIG. 3, only information within the expiration date is transmitted, so that it is possible to avoid transmitting unnecessary information whose expiration date has expired to another vehicle. Further, since the integrated information can be transmitted by the processing of FIG. 2, the amount of transmission information can be made constant even when the number of data increases. Therefore, the communication load can be reduced.

  As described above, according to the inter-vehicle information communication device 1 according to the first embodiment, the integrated calculation processing unit 11 generates integrated information that integrates information related to the same event, and the expiration date calculating unit 12 calculates the integrated information. The expiration date of the integrated information can be calculated based on the generation times of the plurality of pieces of information that are the sources. As described above, since the generation times of a plurality of pieces of information that are the basis of the integrated information can be reflected in the expiration date of the integrated information, it is possible to appropriately calculate the expiration date of the integrated information. Therefore, the freshness of information can be maintained. By recording the integrated information, the storage capacity can be reduced while maintaining the information freshness. Furthermore, the transmission / reception control unit 10 can reduce the communication load while maintaining the information freshness by using the integrated information in which the expiration date is appropriately set at the time of transmission.

(Second Embodiment)
The inter-vehicle information communication device according to the second embodiment is configured in substantially the same manner as the inter-vehicle information communication device 1 according to the first embodiment, and the expiration date is calculated by distinguishing between a transmission expiration date and a use expiration date. Is different. Therefore, the second embodiment will be described with a focus on differences from the first embodiment, and a duplicate description will be omitted.

  The configuration of the inter-vehicle information communication device according to the second embodiment is substantially the same as the configuration of the inter-vehicle information communication device 1 according to the first embodiment shown in FIG. Is different. The expiration date calculation unit 12 of the inter-vehicle information communication device according to the second embodiment has a function of calculating the expiration date of information by distinguishing it from a transmission expiration date and a use expiration date. The transmission expiration date is a time limit that determines a period during which the vehicle 3 can transmit the information, and the use expiration date is a time limit that determines a period during which the vehicle 3 can use the information. The expiration date calculation unit 12 has a function of calculating a transmission expiration date by, for example, setting the generation time of information as the lifetime origin and adding the transmission lifetime to the lifetime origin. In addition, the expiration date calculation unit 12 has a function of calculating the usage expiration date by, for example, setting the information generation time as the lifetime origin and adding the usage lifetime to the lifetime origin. The transmission effective period and the use effective period may be changed for each information or may be a constant value, but here, the transmission effective period is set to be shorter than the use effective period. That is, the transmission expiration date is set to be shorter than the usage expiration date. Further, the method of adopting the lifetime origin of the expiration date calculation unit 12 is the same as in the first embodiment. Further, the information stored in the data DB 31 is associated with a transmission expiration date and a usage expiration date as the expiration date. Other configurations are the same as those of the first embodiment.

  Next, the transmission / reception operation of the inter-vehicle information communication apparatus according to the present embodiment will be described. The transmission / reception operation of the inter-vehicle information communication device according to the second embodiment is substantially the same as the transmission / reception operation of the inter-vehicle information communication device 1 according to the first embodiment, and the expiration date calculation processing of S12 and S20 in FIG. , And S16 are different. Therefore, the expiration date calculation process and the integration determination process will be described with reference to FIG.

First, a process for calculating the expiration date of received data, which is a process corresponding to the process of S12 in FIG. 2, will be described. FIG. 5 is a schematic diagram for explaining the operation of the inter-vehicle information communication device 1. In FIG. 5, as in FIG. 4, the life of information is displayed with the horizontal axis as the time axis. FIG. 5 shows the information generation time t _S , information amount S, transmission expiration date t _X , and usage expiration date t _Y along with the information name. Here, it is assumed that the vehicle 3 has the information A with the transmission life period X of 3 seconds, the service life period Y of 5 seconds, and the information amount 1 before the processing of FIG. For convenience of explanation, the generation time t _S of the holding information A is set to 0. In addition, it is assumed that the information B is generated in the other vehicle when the time t = 2. As described above, when the information A is included at time t = 0, a process for setting the transmission expiration date t _X and the usage expiration date t _Y for the information B received in the processing of S10 will be described. As shown in FIG. 5, it is assumed that the information B and its generation time t _S are received from another vehicle when the time Now ₁ = 2.5. In this case, the expiration date calculating unit 12 uses the generation time t _S = 2 of the information B as the lifetime origin, and adds a predetermined transmission lifetime X and a usage lifetime Y, respectively, so that the transmission expiration date t _X of the information B, used to calculate the expiration date _{t Y.} The transmission life period X and the service life period Y may be variable for each piece of information. However, in consideration of ease of explanation, the transmission life period and the service life period of the information A and the information B are assumed to be the same. To do. That is, the expiration date calculation unit 12 calculates the transmission expiration date t _X = 5 of the reception information B by adding the transmission lifetime period X = 3 to the generation time t _S = 2 when the information B is generated. Then, the expiration date calculating unit 12 calculates the usage expiration date t _Y = 7 of the reception information B by adding the usage lifetime Y = 5 to the generation time t _S = 2 of the information B.

Next, a process for determining whether or not to perform a process of integrating a plurality of pieces of information of the same event, which is a process corresponding to the process of S16 in FIG. The integrated arithmetic processing unit 11 determines whether or not to perform integration processing based on the transmission expiration date among the expiration dates. For example, as shown in FIG. 5, it is assumed that information B of the same event as possessed information A is received at time t = 2. Because the transmission Expiration t _X holdings information A is 3 holding information A is effective as information. For this reason, it is determined that the holding information A and the reception information B are integrated.

Next, a process for calculating the validity period of the integrated information, which is a process corresponding to the process of S20 in FIG. For example, the expiration date calculation unit 12 calculates the expiration date of the integrated data based on the generation time of the data that is the source of the integrated data. Similar to the first embodiment, using the expression 1, holding information A (information amount S = 1, generation time t _S = 0) and reception information B (information amount S = 3, generation time t _S = 2) Are integrated to generate integrated information C (information amount S = 4). Then, like the first embodiment, using Equation 2, and to produce a generation time t _S of integrated information C using the generation time t _S and the information amount S of the underlying information A, B of the integrated . In this case, the expiration date calculating unit 12 sets the calculated generation time t _S as the lifetime origin, and adds the predetermined transmission lifetime X and the usage lifetime Y, thereby adding the transmission expiration date t _X of the information B, the usage expiration date. t _Y is calculated. The transmission life period X and the service life period Y may be variable for each piece of information, but here are set to constants 3 and 5 in consideration of ease of understanding. That is, the expiration date calculating unit 12 calculates the transmission expiration date t _X = 4.5 of the integrated information C by adding the transmission lifetime X = 3 to the generation time t _S = 1.5 of the integrated information C. To do. Further, the expiration date calculating unit 12 calculates the usage expiration date t _Y = 6.5 of the integrated information C by adding the usage lifetime Y = 5 to the generation time t _S = 1.5 of the integrated information C. To do.

As described above, in the inter-vehicle information communication apparatus according to the second embodiment, the expiration date can be set separately for the transmission expiration date and the usage expiration date, and thus, for example, information with good freshness is transmitted to other vehicles. Thus, it is possible to set so as to simultaneously satisfy two requirements of sharing information and securing a certain period of use in the own vehicle. In addition, by setting the transmission expiration date to be shorter than the usage expiration date, it is possible to avoid transmitting the information immediately before being unusable to other vehicles. Thereby, only useful information can be transmitted. Moreover, compared with the inter-vehicle information communication apparatus 1 according to the first embodiment, it is possible to more appropriately avoid a situation in which information is extended forever. For example, in FIG. 4, the integrated information E is generated by integrating the integrated information C and the received information D. The expiration date of the integrated information E is t _T = 8.4, which is shorter than the expiration date t _T = 10 of the integrated information E shown in FIG. However, for example, when the time Now ₂ = 6, since the expiration date of the information A is originally expired, it is more preferable not to use the information including the information A when generating the integrated information E. In the inter-vehicle information communication apparatus according to the second embodiment, as shown in FIG. 5, when the information D is received at time Now ₂ = 6, the transmission expiration date t _X of the integrated information C is 4.5. The integrated information C is invalid as information. For this reason, the reception information D is directly used as the integration information E without performing the process of integrating the integration information C and the reception information D. Then, the integrated information E does not include the information A that has expired. As described above, in the inter-vehicle information communication device according to the second embodiment, it is possible to appropriately avoid a situation in which information is extended forever compared to the inter-vehicle information communication device according to the first embodiment.

  As described above, according to the vehicle-to-vehicle information communication device according to the second embodiment, it is possible to treat the transmission expiration date for other vehicles and the expiration date for use in the host vehicle separately for one piece of information. It is possible to ensure use in the host vehicle while maintaining the freshness of the information to be transmitted. In addition, when integrated information is generated in a state where there is little information with good freshness, the integrated information will reach the transmission expiration date relatively early, but the use expiration date may be adopted for use in the own vehicle. This makes it possible to use information over a long period of time.

  Furthermore, according to the vehicle-to-vehicle information communication apparatus according to the second embodiment, since the transmission expiration date is calculated to be shorter than the usage expiration date, it is possible to avoid transmitting information immediately before it becomes unusable to other vehicles. can do. For this reason, it is possible to effectively use communication resources.

  In addition, embodiment mentioned above shows an example of the information communication apparatus between vehicles which concerns on this invention. The inter-vehicle information communication device according to the present invention is not limited to the inter-vehicle information communication device according to each embodiment, and the inter-vehicle information communication according to each embodiment is within the scope not changing the gist described in each claim. The device may be modified or applied to others.

  For example, in the above-described embodiment, the example in which the information is integrated by the reception process of FIG. 2 has been described. However, the integration process or the like may be performed by the transmission process of FIG.

  Further, in the above-described embodiment, an example in which each vehicle sets an expiration date has been described. However, communication may be performed by including the expiration date in information to be transmitted, and the expiration date may be used as a common communication target vehicle. good.

  In the above-described embodiment, the example in which the generation time of the integrated information is calculated and the expiration date is set based on the generation time of the information that is the source of the integrated information has been described. The generation time of the integrated information may be calculated or the expiration date may be set based on the time or the expiration date. When using the reception time of the information that is the source of the integrated information, for example, by replacing the generation time of the information that is the source of the integrated information in Expression 2 with the reception time, the generation time of the integrated information by the weighted average of the information amount Can be calculated. In this case, the generation time may not be included in the information to be transmitted. Also, when using the expiration date of the information that is the basis of the integrated information, for example, the expiration date of the integrated information can be calculated by a weighted average of the information amount by replacing the generation time of Equation 2 with the expiration date. It becomes. In this case, it is necessary to include not the generation time but the expiration date in the information to be transmitted.

  In the first embodiment described above, the lifetime T is a constant, but may be variable according to the traffic volume, for example. In the second embodiment described above, the transmission lifetime X is a constant, but may be variable according to the traffic volume, for example. It is conceivable that the amount of acquired information increases as the traffic volume increases, and the processing of the vehicle 3 is delayed. For example, the traffic volume increases by setting the effective period T or the transmission life period X shorter as the traffic volume increases. As transmission increases, transmission can be quickly terminated. For this reason, it becomes possible to avoid the processing delay of the vehicle 3 and to reduce the communication load.

  Furthermore, in the second embodiment described above, the case where both the transmission expiration date and the usage expiration date are employed as the expiration date has been described, but only one of the transmission expiration date and the usage expiration date may be employed.

  DESCRIPTION OF SYMBOLS 1 ... Inter-vehicle information communication apparatus, 2 ... ECU, 3 ... Vehicle, 10 ... Transmission / reception control part (communication means), 11 ... Integrated arithmetic processing part (statistical processing means), 12 ... Expiration date calculation part (expiration date calculation means) , 13: Recording processing unit (recording means), 30: Communication device.

Claims (5)

An inter-vehicle information communication device that performs inter-vehicle communication,
A communication means capable of transmitting and receiving information;
An expiration date calculating means for calculating an expiration date that defines a period to be treated as information for the information received by the communication means or the information of the host vehicle;
Statistical information means for generating integrated information by integrating a plurality of pieces of information related to the same event among the information received from other vehicles and the information possessed by the own vehicle, or a plurality of pieces of information received from other vehicles;
With
The expiration date calculating means calculates an expiration date of the integrated information based on an acquisition time, a generation time, or an expiration date of the plurality of pieces of information that are the basis of the integrated information;
A vehicle-to-vehicle information communication device.   The inter-vehicle information communication device according to claim 1, wherein the communication unit transmits the information or the integrated information based on the expiration date. The information or the inter-vehicle information communication device according to claim 1 or 2 comprising a recording means for recording in association with the expiration date of the integrated information.   The expiration date calculating means employs, as the expiration date, at least one of a transmission expiration date that defines a period during which the information can be transmitted and an expiration date that defines a period during which the vehicle can use the information. The inter-vehicle information communication apparatus according to any one of the above.   5. The inter-vehicle information communication according to claim 4, wherein the expiration date calculating unit calculates the transmission time limit to be shorter than the usage time limit when the transmission time limit and the usage time limit are adopted as the expiration date. 6. apparatus.

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