COMMUNICATION TAX DEVICE

Abstract

Communication control device (13) for a vehicle, comprising: - a short-range communication processing unit (F3) that performs direct vehicle-to-vehicle communication, without traversing a long-range communication network (3), with a peripheral vehicle arranged around the vehicle, in cooperation with a short-range communication module (11) for performing direct wireless communication with an external device without traversing the long-range communication network (3); - a long-range communication processing unit (F4) that performs indirect vehicle-to-vehicle communication, which does traverse the long-range communication network (3).with the peripheral vehicle in cooperation with a long-range communication module (12) for wireless communication with the external device via the long-range communication network (3); - a vehicle data generation unit (F2) that generates vehicle data indicating a driving state of the vehicle based on a detection result from a sensor (20) attached to the vehicle; and - a communication quality determination unit (F7) that determines whether a communication quality of the direct vehicle-to-vehicle communication provided by the short-range communication processing unit (F3) is greater than or equal to a predetermined permissible level, wherein - the short-range communication processing unit (F3) wirelessly transmits a communication packet containing the vehicle data in a predetermined short-range transmission cycle from the short-range communication module (11),- the long-range communication processing unit (F4) executes a process to send the communication packet containing the vehicle data to the peripheral vehicle in a predetermined long-range transmission cycle via the long-range communication module (12) and the long-range communication network (3); - the long-range communication processing unit (F4) selects a predetermined first long-range transmission cycle, which is longer than the short-range transmission cycle, as the long-range transmission cycle when the communication quality determination unit (F7) determines that the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the predetermined allowable level; and - the long-range communication processing unit (F4) selects a predetermined second long-range transmission cycle, which is less than or equal to the short-range transmission cycle, as the long-range transmission cycle when the communication quality determination unit (F7) determinesthat the communication quality of the direct vehicle-to-vehicle communication is below the predetermined permissible level.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application is based on Japanese patent application No. 2016-55975, filed on March 18, 2016, the full disclosure of which is hereby incorporated by reference. AREA OF INVENTION

[0002] The present invention relates to a communication control device that controls the operation of a communication module for performing vehicle-to-vehicle communication. CURRENT STATE OF THE TECHNOLOGY

[0003] In recent years, a vehicle-to-vehicle communication system has been proposed in which each of several vehicles sends out a communication packet (hereinafter referred to as a vehicle information packet) in turn, indicating vehicle information such as an instantaneous position, speed or direction of travel, and receives a vehicle information packet sent by another vehicle in turn.

[0004] In the vehicle-to-vehicle communication system described above, as disclosed in patent document 1, one mode of communication between vehicles (i.e., vehicle-to-vehicle communication) is assumed to be a mode of direct sending and receiving of the vehicle information packet between the vehicles, rather than via a wide area communication network. Direct wireless communication between the vehicles is achieved by applying a CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) method as an access control method.

[0005] Furthermore, vehicle information about other vehicles, obtained through vehicle-to-vehicle communication, is used for vehicle control, supporting driver activity, autonomous driving, providing information to the driver, and similar functions. For this reason, the vehicle information gathered through vehicle-to-vehicle communication must be real-time information, as close as possible to the current situation. Given this requirement, the transmission cycle of the vehicle information packet is often set to a few hundred milliseconds (more precisely, 100 ms). LITERATURE FROM THE STATE OF THE TECHNOLOGY PATENT DOCUMENT

[0006] Patent Document 1: JP 2013-5186 A BRIEF SUMMARY OF THE INVENTION

[0007] When vehicles implement direct wireless communication via CSMA / CA, known problems such as the hidden terminal problem and shadowing by large vehicles, such as trucks, must be considered. The hidden terminal problem arises when radio signal interference occurs because multiple vehicles are positioned in a way that prevents them from receiving signals from each other. Furthermore, shadowing occurs when large vehicles obstruct the radio wave, even though the vehicles could communicate with each other given the distance, and the vehicle information packet is temporarily unavailable or the received signal strength is reduced.

[0008] As a solution to the problems mentioned above, it is conceivable to use a configuration in which the vehicles communicate and exchange vehicle information packets via the wide area network (WAN). However, if the vehicles communicate with each other via the WAN, communication costs may arise based on the amount of traffic. Consequently, if vehicle-to-vehicle communication is implemented via the WAN, there is a need to reduce the transmission frequency of the vehicle information packet to lower communication costs, and a need to reduce the transmission interval of the vehicle information packet to share real-time vehicle information with the respective vehicles. These needs are contradictory.

[0009] The object of the present invention is to provide a communication control device that can reduce communication costs while enabling the exchange of vehicle information in real time.

[0010] According to one aspect of the present invention, a communication control device for a vehicle comprises: a short-range communication processing unit that performs direct vehicle-to-vehicle communication, which is direct vehicle-to-vehicle communication without traversing a long-range communication network, with a peripheral vehicle arranged around the vehicle, in cooperation with a short-range communication module for performing direct wireless communication with an external device without traversing the long-range communication network; a long-range communication processing unit that performs indirect vehicle-to-vehicle communication, which is indirect vehicle-to-vehicle communication that takes place via the long-range communication network.with the peripheral vehicle in cooperation with a long-range communication module for wireless communication with the external device via the long-range communication network; a vehicle data generation unit that generates vehicle data indicating a driving state of the vehicle based on a detection result from a sensor mounted on the vehicle; and a communication quality determination unit that determines whether the communication quality of the direct vehicle-to-vehicle communication provided by the short-range communication processing unit is sufficient.is greater than or equal to a predetermined permissible level. The short-range communication processing unit wirelessly transmits a communication packet containing the vehicle data from the short-range communication module in a predetermined short-range transmit cycle. The long-range communication processing unit executes a process to transmit the communication packet containing the vehicle data to the peripheral vehicle via the long-range communication module and the long-range communication network in a predetermined long-range transmit cycle. The long-range communication processing unit selects a predetermined first long-range transmit cycle, which is longer than the short-range transmit cycle, when the communication quality determination unit determines thatthat the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the predetermined permissible level. The long-range communication processing unit selects a predetermined second long-range transmit cycle, which is less than or equal to the short-range transmit cycle, as the long-range transmit cycle if the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is below the predetermined permissible level.

[0011] In the communication control device described above, if the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the permissible level, the vehicle information packet is sent via indirect vehicle-to-vehicle communication in the relatively long first long-distance transmission cycle. Conversely, if the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is below the permissible level, the vehicle information packet is sent via indirect vehicle-to-vehicle communication in the relatively short second long-distance transmission cycle.

[0012] According to the configuration described above, if the communication quality of the direct vehicle-to-vehicle communication falls below the permissible level, for example due to the hidden device problem or shadowing by large vehicles, the transmission of vehicle data via indirect vehicle-to-vehicle communication is implemented with relatively high density. This ensures that a real-time exchange of vehicle information can be maintained.

[0013] Furthermore, if the communication quality of direct vehicle-to-vehicle communication is greater than or equal to the permissible level, real-time exchange of vehicle information can be achieved through direct vehicle-to-vehicle communication. Consequently, even if the long-range transmission cycle is set to a relatively long period, the real-time capability of vehicle-to-vehicle communication is not impaired. Setting the long-range transmission cycle to a relatively high value corresponds to a reduction in the frequency at which communication is carried out by the long-range communication network, thereby reducing communication traffic and costs.

[0014] More precisely, according to the configuration described above, communication costs can be reduced while real-time exchange of vehicle information is achieved. List of characters

[0015] The above and further tasks, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings. The drawings show: Fig. 1. A block diagram illustrating an example of a schematic configuration of a vehicle-to-vehicle communication system; Fig. 2. A block diagram illustrating an example of a schematic configuration of a vehicle system; Fig. 3 a flowchart to illustrate a long-range transmission cycle control process; Fig. 4. An illustration to demonstrate the operation of a communications control unit when a long-distance transmission cycle is set to a first cycle; Fig. 5. An illustration to demonstrate the operation of the communication control unit when the long-distance transmission cycle is set to a second cycle; Fig. 6. An illustration to demonstrate another mode of the second cycle; Fig. 7. An illustration to demonstrate yet another mode of the second cycle; Fig. 8 an illustration to demonstrate yet another mode of the second cycle; Fig. 9 a block diagram to illustrate a modification of the vehicle system configuration; Fig. 10. A block diagram to illustrate a further modification of the vehicle system configuration; and Fig. 11 a block diagram to illustrate a configuration of a communication control unit according to a modification 7; EXECUTIONAL FORMS FOR IMPLEMENTING THE INVENTION

[0016] Embodiments of the present invention are described below with reference to the accompanying drawings. Fig. Figure 1 shows an illustration of an example of a schematic configuration of a vehicle-to-vehicle communication system. 100 of the present invention. As in Fig. As shown in 1, the vehicle-to-vehicle communication system 100 multiple vehicle systems 1 , which are installed in the several vehicles Ma or Mb, and a center 2 on.

[0017] In the Fig. For the sake of simplicity, only two vehicles, Ma and Mb, are shown as vehicles on which the respective vehicle systems are based. 1 are applied (hereinafter referred to as application vehicles). In fact, however, there may be three or more than three vehicles. Below is when the vehicle systems installed in vehicles Ma and Mb are 1To be distinguished are the vehicle system installed in the vehicle Ma 1 as a vehicle system 1a designated and the vehicle system installed in the vehicle Mb 1 as a vehicle system 1b designated. <Gesamtüberblick>

[0018] The vehicle-to-vehicle communication system 100 The system is designed to enable the application vehicles to communicate wirelessly with each other. The application vehicles travel on a road. The application vehicles can include four-wheeled vehicles, as well as two-wheeled vehicles, three-wheeled vehicles, or the like. The two-wheeled vehicles can also include motorized bicycles. In the present embodiment, the application vehicles Ma and Mb are, by way of example, four-wheeled vehicles.

[0019] Each of the application vehicles is designed to use wireless communication (so-called vehicle-to-vehicle communication), not via a wide area communication network. 3 , using radio waves of a pre-assigned frequency band. For simplicity, vehicle-to-vehicle communication that does not use the wide area communication network. 3 This occurs, referred to here as direct vehicle-to-vehicle communication. The area in which direct vehicle-to-vehicle communication can be realized is limited by the transmission output power of the radio waves. More precisely, the area in which direct vehicle-to-vehicle communication can be realized is more limited than that of communication via the wide area network. For this reason, direct vehicle-to-vehicle communication is sometimes referred to as "short-range communication".

[0020] The frequency band used for direct vehicle-to-vehicle communication can be appropriately determined. For example, direct vehicle-to-vehicle communication can be implemented using radio waves from a 760 MHz band (frequency band). Of course, direct vehicle-to-vehicle communication can also be implemented using other radio waves from a 2.4 GHz band, a 5.9 GHz band, or similar bands.

[0021] Any communication standard can be used to implement direct vehicle-to-vehicle communication. In this case, for example, each of the application vehicles performs direct vehicle-to-vehicle communication according to the IEEE WAVE (Wireless Access in Vehicular Environment) standard. 1609 , and the like.

[0022] Each of the application vehicles transmits a communication packet (hereinafter referred to as a vehicle data packet) containing its own vehicle data, via direct vehicle-to-vehicle communication in a predetermined cycle (hereinafter referred to as the short-range transmission cycle) Td to another vehicle around the host vehicle. The vehicle data includes source information, indicating the vehicle that sent the communication packet (i.e., a source vehicle), the time of data generation, the source vehicle's instantaneous position, direction of travel, speed, acceleration, and the like. The source information is identifying information (called a vehicle ID) that is pre-assigned to the source vehicle to distinguish it from other vehicles.

[0023] Each of the application vehicles is designed to be used by the vehicle system installed in the vehicle. 1wirelessly via the wide area communication network 3 to be connected. The wide area communication network. 3 In this example, it refers to a public communications network, such as a mobile phone network or the internet, provided by a telephone company. A [missing word] in the Fig. 1 base station shown 4 is a mobile communication base station for the vehicle system 1 , in order to establish a connection to the wide area communication network 3 to produce.

[0024] Each of the application vehicles sends a communication packet containing the same vehicle data as the vehicle data packet sent through direct vehicle-to-vehicle communication in a predetermined cycle (hereinafter referred to as the long-distance transmission cycle) Tw via the base station. 4 and the wide area communication network 3 to the center 2 .

[0025] Below, to distinguish it from the vehicle data packet that is periodically sent via direct vehicle-to-vehicle communication, is the communication packet containing the vehicle data of the sending source vehicle, which is transmitted via the wide area communication network. 3 to the center 2 The vehicle data packet sent is referred to as a long-range vehicle data packet. Furthermore, the vehicle data packet that is periodically sent through direct vehicle-to-vehicle communication is referred to as a short-range vehicle data packet. However, if it is not necessary to distinguish between the long-range and short-range vehicle data packets, then each vehicle data packet is simply referred to as a vehicle data packet. The following is a transmission of the communication packet to the center. 2 also referred to as long-range transmission, and the transmission of a predetermined communication packet through direct vehicle-to-vehicle communication is also referred to as short-range transmission.

[0026] The center 2 It features a function for transmitting the wide-area vehicle data packet sent from one vehicle to other vehicles (i.e., peripheral vehicles) located around the sending source vehicle. An area around the sending source vehicle is defined as the region within a predetermined vehicle-to-vehicle transmission distance from that vehicle. More precisely, the vehicle-to-vehicle transmission distance serves as a parameter used to extract the vehicles (more specifically, the peripheral vehicles for the sending source vehicle) to which the received wide-area vehicle data packet will be transmitted from the various application vehicles.

[0027] The vehicle-to-vehicle transmission distance can be maintained at a fixed value or dynamically determined according to the speed of the transmitting vehicle. In the latter case, for example, the vehicle-to-vehicle transmission distance is increased when the transmitting vehicle's speed is higher. Other vehicles within the vehicle-to-vehicle transmission distance of the transmitting vehicle are considered peripheral vehicles.

[0028] In another mode, the vehicle-to-vehicle transmission distance can be dynamically adjusted to a value corresponding to the type of road traveled by the transmitting vehicle. When the vehicle-to-vehicle transmission distance is adjusted according to the type of road traveled, if the road is a highway / expressway, the distance will be set to a relatively high value (such as 400 m). Conversely, if the road is a general road, the vehicle-to-vehicle transmission distance can be set to a value that is lower than if the road is a highway.

[0029] The center 2It features a function for managing the current positions of the respective application vehicles as a sub-function for determining a transmission destination for the received long-distance vehicle data packet. Managing the current position of each application vehicle can be implemented using a database (not shown). The database stores the current position of each application vehicle in conjunction with the vehicle ID or similar identifier. For simplicity, data describing the current position of each application vehicle is referred to as position management data. Each time the center 2 The center receives the long-distance vehicle data package and updates it. 2 the current position of the transmitting vehicle, which is registered in the database, with reference to the content of the long-distance vehicle data package.

[0030] When the long-range vehicle data packet sent by an application vehicle is received, the center extracts 2 The vehicles within the vehicle-to-vehicle transmission range are located at a straight-line distance from the transmitting vehicle based on position management data, and the center is transmitted. 2 the received long-distance vehicle data package for the extracted vehicle.

[0031] In this way, the vehicle-to-vehicle communication system 100 indirect vehicle-to-vehicle communication via the wide area communication network 3 ready. To distinguish it from direct vehicle-to-vehicle communication, indirect vehicle-to-vehicle communication is via the wide area communication network. 3 Also referred to below as indirect vehicle-to-vehicle communication. The following is a configuration of the vehicle system installed in each vehicle. 1described in more detail. <Konfiguration von Fahrzeugsystem 1 >

[0032] In this case, a configuration of the vehicle system is required. 1 insofar as the vehicle system 1a The configuration installed in the application vehicle Ma is described as an example. 1 applied, which are installed in other application vehicles (such as the Mb vehicle). For simplicity, the vehicle in which the vehicle system in question is installed is 1 is installed (i.e., the vehicle Ma), also referred to as a host vehicle to distinguish it from the vehicles in which the other vehicle systems are installed. 1 are installed.

[0033] As in Fig. 2 shown, the vehicle system 1 a communication unit 10 , a sensor 20 and a position transmitter 30 up. The communication unit10 is connected to the sensor via a communication network integrated into the vehicle (i.e., LAN: Local Area Network or local network). 20 and the position giver 30 tied together.

[0034] The communication unit 10 It is designed to send and receive vehicle data packets relating to peripheral vehicles. The communication unit 10 features a short-range communication module 11 , a long-distance communication module 12 and a communication control unit 13 as further elements. The short-range communication module 11 and the long-distance communication module 12 are connected to the communication control unit 13 connected in order to communicate with each other.

[0035] The short-range communication module 11It is designed to perform direct wireless communication (i.e., direct vehicle-to-vehicle communication) with other vehicles using radio waves within a predetermined frequency band. The short-range communication module 11 It features a short-range communication antenna and a short-range communication transmit and receive unit (not shown) as more detailed elements.

[0036] The short-range communication antenna is designed to transmit and receive radio waves in the frequency band used for direct vehicle-to-vehicle communication. The short-range communication transmitter and receiver demodulates a signal received from the short-range communication antenna and forwards the demodulated signal to the communication control unit. 13 to give, and modulated by the communication control unit 13Input data is used to send the modulated data to the short-range communication antenna and transmit the output data wirelessly. Access control for direct vehicle-to-vehicle communication is implemented using CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance). The access control process based on CSMA / CA can be managed by the short-range communication transmitter and receiver or by the communication control unit. 13 be handled.

[0037] The long-distance communication module 12 is designed to establish a wireless connection to the wide area communication network 3 to produce and to the vehicle system 1 to enable communication via the wide area communication network 3 to communicate with another communication device. The long-range communication module 12It includes a long-range communications antenna and a long-range communications transmit and receive unit (not shown) as further elements.

[0038] The long-range communication antenna is designed to receive radio waves from the predetermined frequency band used for wireless communication with the base station. 4 It is used to send and receive signals. The long-range communication transmit and receive unit demodulates a signal received by the long-range communication antenna in order to send the demodulated signal to the communication control unit. 13 to give, and modulated by the communication control unit 13 Input data to send the modulated data to the long-range communication antenna and to transmit the output data wirelessly.

[0039] The long-distance communication module 12serves as a communication module that transmits the received data to the communication control unit 13 there are those from the communication control unit 13 The input data is modulated and the modulated data is sent to an external device (such as a center). 2 ) transmits, in cooperation with the long-range communication antenna and the long-range communication transmit and receive unit.

[0040] The communication control unit 13 controls the operation of the short-range communication module 11 and the long-distance communication module 12 The communication control unit 13 The communication control unit is described in more detail separately below, but is briefly outlined below. 13 generates the vehicle data based on the information provided by the sensor 20is provided, and causes the vehicle data package containing the vehicle data from the short-range communication module to be sent. 11 or from the long-distance communication module 12 to be sent. Sending the communication packet from the short-range communication module. 11 This corresponds to the short-range transmission described above, and the transmission of the communication packet from the long-range communication module. 12 This corresponds to the long-distance transmission described above. Furthermore, the communication control unit receives 13 The vehicle data packet sent by the peripheral vehicles through direct vehicle-to-vehicle communication and indirect vehicle-to-vehicle communication.

[0041] The sensor 20It includes various sensors for detecting different parameters related to the host vehicle's movement. These parameters include, for example, vehicle speed, yaw rate, steering angle, acceleration, gear position, and the like. More precisely, the sensor 20 It includes a speed sensor that detects the vehicle speed, a yaw rate sensor that detects the yaw rate, a steering angle sensor that detects the steering angle, an acceleration sensor that detects any acceleration acting on the vehicle, a shift position sensor, and the like. The position information, which indicates the current position of the host vehicle, is provided by the position sensor. 30 The identified condition, which is described below, is also included in the status amounts relating to the journey of the host vehicle.

[0042] The sensor's detection result 20is sent sequentially to the communication unit via the LAN 10 Given. The recording results from the various sensors. 20 can be connected to the communication unit via any ECU (Electronic Control Unit). 10 be given. The sensors according to the sensor 20 are not limited to those described above. Furthermore, it is not necessary to provide all of the sensors described above. The type of sensor 20 can be determined in a suitable manner.

[0043] The position giver 30 is designed to identify a point where the host vehicle is currently located on a road map. The position transmitter 30 features a GNSS (Global Navigation Satellite System) receiver 31 and a map storage unit 32 as closer components.

[0044] The GNSS receiver 31 It receives a navigation signal sent by a navigation satellite that is part of a GNSS (Global Navigation Satellite System), which is a satellite navigation system, and sequentially calculates an instantaneous position based on the received navigation signal.

[0045] The card storage unit 32 It stores road map data that describes road connections and road layouts (more precisely, road structures). The map storage unit 32 can be achieved using a non-volatile storage medium, such as a hard disk drive.

[0046] The position giver 30 Identifies the position of the host vehicle on the road map based on the current position provided by the GNSS receiver. 31The vehicle's position is recorded. The identification of the vehicle's position on the road map is also referred to as "mapping." Mapping the vehicle's position can be performed using a known map-matching method commonly employed in navigation devices. This method involves obtaining the vehicle's location from its direction and speed at multiple points in time and comparing this location with the road's path, as determined by the map information, to ascertain the vehicle's current position.

[0047] The position giver 30 It sequentially transmits position information, indicating the current position, to the communication unit. 10 The position giver 30It can have the functions described above, and when the navigation device is installed in the host vehicle, the navigation device can act as the position transmitter. 30 be used. <Konfiguration der Kommunikationseinheit 10 >

[0048] Below is the communication unit 10 described. The communication control unit 13 This corresponds to a communication control device. The communication control unit 13 It is configured as a computer that has a CPU, RAM, ROM, I / O, and a bus connecting these components. The ROM stores a program (hereinafter referred to as the communication control program) that causes a normal computer to act as the communication control unit. 13 to serve as a vehicle ID and the like.

[0049] The communication control program described above can be stored on a non-volatile physical storage medium, and the storage medium is not limited to ROM. For example, the communication control program can be stored in flash memory. Execution of the communication control program by the CPU is equivalent to executing a procedure according to the communication control program.

[0050] The communication control unit 13 provides various functions that are in the Fig. 2 are shown by causing the CPU to execute the communication control program described above, which is stored in ROM. More precisely, the communication control unit 13 It features, as functional blocks, a vehicle information acquisition unit F1 , a vehicle data generation unit F2 , a short-range communication processing unitF3 , a wide area communications processing unit F4 , a receiving data management unit F5 , a peripheral vehicle identification unit F6 and a communication quality assessment unit F7 Furthermore, the communication control unit features 13 a storage M1 on, which is implemented using a rewritable storage medium, such as RAM.

[0051] Incidentally, some or all of the functional blocks in the communication control unit may be 13 These components can be implemented using one or more integrated circuits (ICs) or similar devices (more precisely, as hardware). Furthermore, some or all of the functional blocks contained in the communication control unit can be implemented using one or more ICs or similar components (more precisely, as hardware). 13 are contained within, and are realized through a combination of software execution by the CPU with hardware elements.

[0052] The vehicle information acquisition unit F1 The sensor captures various pieces of information (i.e., vehicle information) that indicate the driving status of the host vehicle. 20 and the position giver 30 via the LAN. In particular, the vehicle information acquisition unit records F1 The current position, speed, yaw rate, direction of travel, and similar information of the host vehicle. Various pieces of information obtained by the vehicle information acquisition unit. F1 When recorded, the data is stored in memory for a specific period of time. M1 saved.

[0053] The vehicle data generation unit F2 The vehicle data, which indicates the vehicle's driving status at the time of generation, is generated in a predetermined generation cycle Tg based on the various pieces of information stored in the memory. M1is stored. The generation cycle Tg can be, for example, 100 ms. This is generated by the vehicle data generation unit. F2 The vehicle data generated corresponds to a data body section (so-called user data) that is contained within the vehicle data package. The data generated by the vehicle data generation unit... F2 The generated vehicle data is stored in the memory. M1 stored and sent to the near-field communication processing unit F3 and the long-range communications processing unit F4 given.

[0054] Each time the vehicle data is sent from the vehicle data generation unit F2 The near-field communication processing unit generates the data to be provided. F3 a short-range vehicle data package containing the vehicle data and outputs the short-range communication processing unit F3 the generated short-range vehicle data package to the short-range communication module 11The short-range communication module 11 modulates the signal from the near-field communication processing unit F3 The system inputs a short-range vehicle data packet and transmits it (broadcasting).

[0055] The vehicle data generation unit F2 As described above, data is generated in the generation cycle Tg. Therefore, a cycle (i.e., a short-range transmission cycle) Td, in which the short-range communication processing unit... F3 the short-range vehicle data packet is transmitted, corresponding to the generation cycle Tg. More precisely, in the present embodiment, the short-range transmission cycle Td is set to match the generation cycle Tg.

[0056] Furthermore, the near-field communication processing unit captures F3 from the short-range communication module 11Received data (such as a short-range vehicle data packet from another vehicle). The short-range communication processing unit F3 transmits the vehicle data displayed by the captured short-range vehicle data packet to the receiving data management unit. F5 The vehicle data of the other vehicle, which is processed by the short-range communication processing unit. F3 Data that is captured can be transmitted to another ECU via the LAN.

[0057] In the present embodiment, according to one example, the vehicle data generation unit generates F2 spontaneously generates the vehicle data in the predetermined generation cycle Tg and outputs the vehicle data generation unit. F2 the generated vehicle data to the short-range communication processing unit F3 or the like; the operation of the vehicle data generation unit F2 However, it is not limited to the above-mentioned operation.

[0058] According to another mode, the vehicle data generation unit F2 the vehicle data package based on a request from the short-range communication processing unit F3 generate. In this case, the near-field communication processing unit queries F3 at the vehicle data generation unit F2 to generate the vehicle data in every short-range transmission cycle Td. Even in this mode, the short-range vehicle data packet is sent in the short-range transmission cycle Td.

[0059] The long-distance communications processing unit F4 The long-distance vehicle data package is generated using the vehicle data provided by the vehicle data generation unit. F2 are generated within the predetermined long-range transmission cycle Tw. The long-range communications processing unit F4generates the long-distance vehicle data packet to have the same vehicle data as the short-distance vehicle data packet that is sent at a time when the long-distance transmission cycle Tw is ending.

[0060] The long-distance communication processing unit then provides F4 the generated long-distance vehicle data package to the long-distance communication module 12 and sends the long-range communications processing unit F4 The long-range vehicle data package is transmitted wirelessly. More precisely, the long-range communication processing unit. F4 Executes a processing step to transmit the long-distance vehicle data packet within the predetermined long-distance transmission cycle Tw. The long-distance vehicle data packet originates from the long-distance communication module. 12 The data is transmitted via the base station 4 , the wide area communication network 3and the center 2 given to the peripheral vehicles of the host vehicle.

[0061] The cycle (i.e., the long-range transmission cycle) Tw per se, in which the long-range vehicle data packet is to be generated and transmitted, is managed by the long-range communications processing unit. F4 dynamically changed. In the present embodiment, a first cycle Tw1 and a second cycle Tw2, which differ in length, are pre-registered in the ROM as setting values ​​that can be applied as the long-range transmission cycle Tw. The long-range communication processing unit F4 selects a cycle to be used as the long-distance transmission cycle Tw from the first cycle Tw1 and the second cycle Tw2 based on the determination results of the peripheral vehicle determination unit. F6 and the communication quality determination unit F7, which are described below. The first cycle Tw1 corresponds to a first long-distance transmission cycle, and the second cycle Tw 2 This corresponds to a second long-distance transmission cycle.

[0062] The first period Tw1 can be set to a higher value than the second cycle Tw2. For example, the first cycle Tw1 is set to 10 times (i.e., 1 second) the short-range transmit cycle Td, and the second cycle Tw2 is set to 1 time (i.e., 100 ms) the short-range transmit cycle Td. The first cycle Tw1 can, of course, also be set to 0.5 s, 0.8 s, 2 s, or similar values.

[0063] Preferably, however, both the first cycle Tw1 and the second cycle Tw2 are set to integer multiples of the short-range transmission cycle Td (more precisely, the generation cycle Tg of the vehicle data). This serves to ensure that the vehicle data described by the long-range vehicle data packet, which is transmitted over a large area, has the same content as the vehicle data described by the short-range vehicle data packet, which is transmitted in a short range, both before and after the transmission time.

[0064] Furthermore, the first cycle Tw1 is a value set as the long-range transmission cycle Tw to reduce communication traffic. Consequently, given the need to reduce communication traffic, the first cycle Tw1 is preferably set to a relatively high value. This is because the communication traffic is routed over the long-range communication network. 3further increases if the long-distance transmission cycle Tw has a lower value, and communication costs continue to rise.

[0065] In contrast, the second cycle, Tw2, is a value that should be set as the long-distance transmission cycle, Tw, when real-time information exchange between vehicles is required. Consequently, given the need for real-time information exchange, the transmission cycle of the vehicle information packet is preferably set to a relatively low value (such as less than or equal to 300 ms). The second cycle, Tw2, can, for example, be set to 200 or 300 ms.

[0066] In conventional vehicle-to-vehicle communication systems, a transmission cycle of approximately a few hundred milliseconds (ms) is assumed for the vehicle data packet. This means that if the transmission cycle is set to 100 ms, as is the case in the present embodiment, the real-time capability of the vehicle-to-vehicle communication is sufficiently ensured. More precisely, to achieve the exchange or sharing of vehicle information in real time, the mutual vehicle information only needs to be exchanged every few hundred milliseconds.

[0067] In the future, if real-time information exchange between vehicles is required, a value corresponding to the request can be used as the second cycle Tw2. In this case, however, it is also assumed that the generation cycle Tg and the short-range transmission cycle Td of the vehicle data will likewise be set to the length corresponding to the request.

[0068] Incidentally, in another mode, the first cycle Tw1 can be set to a higher value (such as greater than or equal to 10,000 s) if the transmission of the long-distance vehicle data packet is essentially not performed. More precisely, the first cycle Tw1 can be set by the long-distance communication processing unit. F4 be set to a value that is considered infinite. Furthermore, the wide area communication processing unit can F4It should be designed not to send the long-distance vehicle data packet when the long-distance transmission cycle is set to the first cycle Tw1.

[0069] Furthermore, the long-distance communication processing unit records F4 from the long-distance communication module 12 Received data (especially a long-range vehicle data packet from another vehicle). The long-range communications processing unit F4 It transmits the vehicle data displayed by the captured long-distance vehicle data package to the receiving data management unit. F5 The vehicle data of the other vehicle, which is processed by the long-distance communication processing unit. F4 Data that is captured can be sent via the LAN to various ECUs.

[0070] The receiving data management unit F5 stores the vehicle data of the other vehicle, which is transmitted by the short-range communication processing unit.F3 and the long-range communications processing unit F4 be recorded in the storage M1 in conjunction with the vehicle ID of the other vehicle. This results in information about the other vehicles present around the host vehicle being managed separately for each vehicle. For simplicity, the vehicle data for each vehicle stored in the memory is M1 They are stored and referred to as peripheral vehicle data.

[0071] Furthermore, it compares when the vehicle data is stored in the memory. M1 The data is stored in the receiving data management unit. F5 the in storage M1 The stored vehicle data is compared with the vehicle data to be stored, and if the same data is already stored, the duplicate data is not saved but deleted. This is because it is unnecessary to store the duplicate data.

[0072] For example, if the vehicle data is from the long-distance communication processing unit F4 will be provided if the same data as the vehicle data is already in memory M1 are stored by the wide area communication processing unit F4 Provided vehicle data deleted.

[0073] In this case, the data in question is data where the vehicle IDs and data generation times match. This applies when the data is the same as the vehicle data provided by the long-distance communication processing unit. F4 be provided, already in storage M1 "are stored" means that the same vehicle data is stored by the short-range communication processing unit. F3 in front of the long-distance communication processing unit F4will be provided. Naturally, even if the vehicle data is provided by the short-range communication processing unit. F3 The same processing is performed to avoid storing duplicate data.

[0074] In the present embodiment, according to a preferred mode, when certain vehicle data is stored, the receiving data management unit stores F5 Whether a vehicle data acquisition path is direct vehicle-to-vehicle communication or indirect vehicle-to-vehicle communication, using a flag or similar means. For example, if the vehicle data is stored by the short-range communication processing unit. F3 The receiving data management unit is provided. F5A flag (ON) indicating the data captured through direct vehicle-to-vehicle communication. Furthermore, when vehicle data is stored from the long-range communication processing unit. F4 The receiving data management unit is provided. F5 A flag (ON) indicating the data captured through indirect vehicle-to-vehicle communication. The receiving data management unit. F5 can set (ON) the respective flags for the data that can be captured via both of these paths.

[0075] The Peripheral Vehicle Identification Unit F6 Determines whether or not another vehicle is present around the host vehicle, based on the peripheral vehicle data stored in memory. M1 are stored. The Peripheral Vehicle Determination Unit F6For example, it determines whether the vehicle data packet of another vehicle has been received within a predetermined time (hereinafter referred to as the determination time) since the current time. If the peripheral vehicle determination unit F6 The peripheral vehicle determination unit determines whether the vehicle data packet of another vehicle has been received within a specified time since the current time. F6 that no other vehicle is present around the host vehicle. In contrast, if the peripheral vehicle determination unit F6 The peripheral vehicle determination unit determines which vehicle has received the vehicle data packet of another vehicle within the determination time. F6 , that the other vehicle is present around the host vehicle.

[0076] The determination time used in this situation can be designed appropriately. However, the determination time is preferably set to be longer than once the length of the first cycle Tw1. For example, the determination time can be set to 1.5 times the length of the first cycle Tw1, or something similar.

[0077] The communication quality determination unit F7This determines whether the communication quality of direct vehicle-to-vehicle communication is greater than or equal to a predetermined permissible level. Various methods can be used to determine whether the communication quality of direct vehicle-to-vehicle communication is greater than or equal to the permissible level. A state in which the communication quality of direct vehicle-to-vehicle communication is greater than or equal to the permissible level describes a state in which the near-field vehicle data packet sent by the peripheral vehicle can be received normally; more precisely, a state in which the probability of the data not being received is less than or equal to a predetermined threshold (such as 10%).

[0078] In this case, according to an example, the communication quality determination unit determines F7The communication quality is deemed to be below the permissible level if another vehicle, which cannot receive the near-field vehicle data packet, is among the other vehicles that should be around the host vehicle. Furthermore, if the near-field vehicle data packet can be received by all of the other vehicles that should be around the host vehicle, the communication quality of the direct vehicle-to-vehicle communication is determined to be greater than or equal to the permissible level. The other vehicle that should be around the host vehicle can be determined based on the long-field vehicle data packet acquired through indirect vehicle-to-vehicle communication.

[0079] It should be noted that, preferably, the other vehicle used as the peripheral vehicle in the communication quality determination process is the other vehicle located within an area where direct vehicle-to-vehicle communication with the host vehicle should be sufficiently feasible. For example, another vehicle located within 100 m of the host vehicle can be used as a peripheral vehicle for determining communication quality. More precisely, it is not necessary to use all of the other vehicles detected through indirect vehicle-to-vehicle communication as the peripheral vehicles.

[0080] The procedure for determining whether or not the communication quality of direct vehicle-to-vehicle communication reaches the permissible level is not limited to the procedure described above. For example, it can be determined, based on the received signal strength (RSSI: Received Signal Strength Indication) of the short-range vehicle data packet acquired through direct vehicle-to-vehicle communication, whether or not the communication quality is greater than or equal to the permissible level.

[0081] In particular, the communication quality can be determined based on the following configuration and procedure. First, the short-range communication module provides 11 the received short-range vehicle data packet RSSI to the short-range communication processing unit F3 and provides the near-field communication processing unit F3the short-range vehicle data package together with the RSSI of the short-range vehicle data package to the receiving data management unit F5 The receiving data management unit F5 The RSSI of the vehicle data packet acquired through direct vehicle-to-vehicle communication is stored in the memory in conjunction with the vehicle data of the other vehicle. M1 It should be noted that the RSSI can be determined using a configuration known as an RSSI circuit.

[0082] There is usually a correlation between the RSSI and the distance between communication devices, with the RSSI increasing as the distance between the communication devices decreases. For this reason, an assumed RSSI value can be predetermined in accordance with the distance between the vehicles. Data (hereinafter referred to as RSSI data) indicating the assumed RSSI value according to the distance between the vehicles can be pre-stored in the ROM or similar as part of a communication control program.

[0083] In such a configuration, the communication quality determination unit determines F7that the communication quality of direct vehicle-to-vehicle communication falls below the permissible level if another vehicle is present whose RSSI of the currently received vehicle data packet is at least one predetermined threshold below the accepted RSSI value, which is determined in accordance with the distance of the other vehicle to the host vehicle. Furthermore, the communication quality determination unit determines F7The communication quality is greater than or equal to the permissible level when no other vehicle is present whose RSSI of the currently received vehicle data packet is at least the predetermined threshold below the accepted RSSI value, which is determined in accordance with the distance of the other vehicle to the host vehicle. According to the determination procedure described above, the communication quality of direct vehicle-to-vehicle communication can be determined without using vehicle data acquired through indirect vehicle-to-vehicle communication. The communication quality can, of course, be determined more accurately by combining the determination of the communication quality with the procedure described above.

[0084] The case where the RSSI of the currently received vehicle data packet falls below the assumed RSSI value, which is determined according to the distance between the vehicles, is considered a case of "shadowing" by a large vehicle or a case where the host vehicle's environment is a vehicle-to-vehicle multipath environment. Both situations tend to degrade the communication quality of direct vehicle-to-vehicle communication (i.e., a situation where direct vehicle-to-vehicle communication is poor). <weitverkehrs-sendezyklussteuerprozess>

[0085] Below is a sample from the communication control unit 13 executed long-range transmission cycle control process with reference to the one in the Fig. The flowchart shown in Figure 3 describes the process. The long-range transmit cycle control process controls the long-range transmit cycle Tw. The long-range transmit cycle control process can be started sequentially (e.g., every 100 ms) while a power supply (e.g., an ignition power supply) of the vehicle is switched on. Alternatively, the long-range transmit cycle control process can be started at a time when the long-range communication processing unit is active. F4 the long-distance vehicle data package to the long-distance communication module 12 gives.

[0086] The Peripheral Vehicle Identification Unit F6 first, in step S1 , to the storage M1 to, reads the peripheral vehicle data and proceeds to step S2 forward. In step S2 determines the peripheral vehicle identification unit F6 , whether or not another vehicle is present around the host vehicle, based on the information in step S1 Read peripheral vehicle data. If it is determined that the other vehicle is present around the host vehicle, in step S2 A positive decision has been made and the process proceeds step by step. S3 forward. If it is determined that the other vehicle is not present around the host vehicle, proceed to step S2 A negative determination has been made and the process proceeds step by step. S4 forward.

[0087] In step S3 determines the communication quality determination unit F7 , whether or not the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to a predetermined permissible level, in accordance with the determination procedure described above. If it is determined that the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the permissible level, in step S3 A positive decision has been made and the process proceeds step by step. S4 forward. In contrast, if it is determined that the communication quality of the direct vehicle-to-vehicle communication is below the permissible level, in step S3 A negative determination has been made and the process proceeds step by step. S5 forward.

[0088] In step S4 sets the long-range communications processing unit F4 the long-distance transmission cycle Tw on the first cycle Tw1 and terminates the long-distance communications processing unit F4 the ongoing process. If the long-distance transmission cycle Tw is already on the first cycle Tw1 If the setting has already been set, it is sufficient to maintain the setting.

[0089] In step S5 sets the long-range communications processing unit F4 the transmission cycle to the second cycle Tw2 and terminates the long-distance communications processing unit F4 the ongoing process. If the long-range transmission cycle Tw already on the second cycle Tw2 If the setting has already been set, it is sufficient to maintain the setting.

[0090] Fig. Figure 4 shows an illustration of the respective operating processes of the vehicle data generation unit. F2 , the short-range communication processing unit F3 and the long-distance communications processing unit F4 , when the long-range transmission cycle Tw on the first cycle Tw1 The x-axis represents time. The downward-pointing triangles in the diagram mark points in time at which the vehicle data generation unit is set. F2 The vehicle data is generated. The arrows on the abscissa correspond to the short-range communication processing unit. F3 and the long-distance communications processing unit F4 The numbers shown indicate the times at which the respective communication processing units send out the vehicle data packets.

[0091] As in Fig. As shown in Figure 4, the near-field communication processing unit transmits F3 the vehicle data package synchronized with the generation of vehicle data by the vehicle data generation unit F2 In contrast, it transmits when the long-range transmission cycle Tw on the first cycle Tw1 is set, the wide area communication processing unit F4 the vehicle data packet once every 10 transmissions of the vehicle data packet by the short-range communication processing unit F3 . In the long-range communications processing unit F4 The vehicle data packet sent contains the same vehicle data as that transmitted by the short-range communication processing unit. F3 The vehicle data packet sent is stored at the same time.

[0092] Fig. Figure 5 shows an illustration of the respective operating processes of the vehicle data generation unit. F2 , the short-range communication processing unit F3 and the long-distance communications processing unit F4 , when the long-range transmission cycle Tw on the second cycle Tw2 is set. The symbols in the illustration have the same meaning as those in the Fig. 4.

[0093] As in Fig. As shown in Figure 5, the long-range communications processing unit sends F4 in the event that the long-range transmission cycle Tw on the second cycle Tw2 The vehicle data packet is set to operate at the same frequency as that of the short-range communication processing unit. F3 out. More precisely, the wide area communication processing unit. F4 This achieves the transmission of information to other vehicles more frequently than when the long-distance transmission cycle is in use. Tw on the first cycle Tw1 is set. <Overview of the design>

[0094] According to the configuration described above, when the peripheral vehicle determination unit F6 determines that another vehicle is present around the host vehicle, and the communication quality determination unit F7 determined that the communication quality of direct vehicle-to-vehicle communication is below the permissible level, the long-distance transmission cycle Tw on the second cycle Tw2 set.

[0095] Furthermore, if the peripheral vehicle determination unit F6 determines that no other vehicle is present around the host vehicle, and the communication quality determination unit F7 determines that the communication quality of direct vehicle-to-vehicle communication is greater than or equal to the permissible level, the long-distance transmission cycle Tw on the first cycle Tw1 set.

[0096] The first cycle Tw1 is compared to the short-range transmission cycle Td and the second cycle Tw2 , set to a relatively higher value to reduce communication traffic. To achieve real-time capability comparable to that of direct vehicle-to-vehicle communication in indirect vehicle-to-vehicle communication—more precisely, to achieve real-time information exchange to the same extent as in direct vehicle-to-vehicle communication—the second cycle is used. Tw2 set to a value that is approximately comparable to that of the near-field transmission cycle Td.

[0097] That is, if the communication quality of the direct vehicle-to-vehicle communication has not reached the permissible level, even though another vehicle is present around the host vehicle, the long-distance communication processing unit sets F4 The long-range transmission cycle Tw is set to a relatively low value (short transmission cycle). In contrast, in other cases, the long-range communication processing unit sets F4 the long-distance transmission period Tw to a relatively high value (long transmission cycle).

[0098] In the event that the communication quality of the direct vehicle-to-vehicle communication has not reached the permissible level, even though another vehicle is present around the host vehicle, there is a possibility that the near-field vehicle data packet, which is sent at a short distance from the other vehicle around the host vehicle, cannot be received.

[0099] Consequently, if the communication quality of the direct vehicle-to-vehicle communication does not reach the permissible level, even though the other vehicle is present around the host vehicle, the long-range transmission cycle Tw is set to a relatively low value to allow the peripheral vehicle to acquire vehicle information about the host vehicle in real time. A reduction in the long-range transmission cycle Tw corresponds to an increase in the transmission frequency of the vehicle data packets to the long-range communication network. 3 and a denser transmission of information to the other vehicles. Furthermore, since the other vehicles operate similarly to the host vehicle, the host vehicle can also collect real-time vehicle information about the peripheral vehicles.

[0100] More precisely, according to the configuration described above, since indirect vehicle-to-vehicle communication serves as a backup unit for direct vehicle-to-vehicle communication, real-time information exchange between vehicles can be maintained even in environments where direct vehicle-to-vehicle communication is poor.

[0101] According to the configuration described above, if no other vehicle is present around the host vehicle, or if the communication quality of the direct vehicle-to-vehicle communication reaches the permissible level, the long-range transmission cycle Tw is set to a relatively high value. An increase in the long-range transmission cycle Tw corresponds to a decrease in the frequency (more precisely, the communication traffic) at which the vehicle data packet is transmitted to the long-range communication network. 3 is being sent.

[0102] If no peripheral vehicles are present around the host vehicle, the vehicle data packet is not used by the peripheral vehicles. Therefore, it is not necessary to send the vehicle data packets frequently. Furthermore, if the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the permissible level, the real-time capability of the vehicle-to-vehicle communication is maintained through the direct vehicle-to-vehicle communication.

[0103] Consequently, if no other vehicle is present around the host vehicle, or if the communication quality of the direct vehicle-to-vehicle communication reaches the permissible level, it is not necessary to shorten the long-distance transmission cycle Tw, and, given a reduction in communication traffic, the long-distance transmission cycle Tw is preferably longer.

[0104] More precisely, according to the configuration described above, communication traffic can be reduced while enabling the exchange of vehicle information in real time.

[0105] The present invention is described above in conjunction with its embodiments. However, the present invention is not limited to the embodiments described above, but can be modified in various ways within its scope of protection. Furthermore, various modifications other than those described below are conceivable within the scope of protection of the present invention.

[0106] Elements with functions identical to those in the embodiment above are identified below with the same reference numerals and are not described repeatedly. Furthermore, if reference is made to only a part of the configuration, the configuration of the embodiment above can be applied to the other sections. [Modification 1]

[0107] In the embodiment described above, the mode for determining whether the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the predetermined permissible level, after determining whether or not the peripheral vehicle is present, has been illustrated. However, the present invention is not limited to the above configuration. Step S2 in the Fig. Step 3 can be omitted. In this case, the communication quality determination unit can be used. F7 Determine whether or not the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the permissible level by referring to the RSSI of the near-field vehicle data packet captured by the direct vehicle-to-vehicle communication. [Modification 2]

[0108] In the embodiment described above, the mode for determining that another vehicle is present around the host vehicle when the vehicle data packet of the other vehicle is received within the determination time since the current time is illustrated by way of example. However, the present invention is not limited to the above configuration.

[0109] If the distance between the position of the other vehicle, as indicated by the received vehicle data, and the position of the host vehicle at a given time of data reception is greater than or equal to a predetermined peripheral determination distance, it can be determined that the other vehicle is not present around the host vehicle. More precisely, even if the vehicle data packet from the other vehicle was received via indirect vehicle-to-vehicle communication or direct vehicle-to-vehicle communication, if the distance between the other vehicle and the host vehicle is greater than or equal to the peripheral determination distance, it can be determined that no other vehicle is present around the host vehicle.

[0110] The peripheral detection distance according to modification 2 This parameter serves as a threshold to determine whether or not the other vehicle communicating directly or indirectly with the host vehicle is to be considered the other vehicle present around the host vehicle. The peripheral determination distance can be the same parameter as the vehicle-to-vehicle transmission distance defined by the center. 2 is used, or can be defined as a separate, independent parameter. Furthermore, the peripheral detection distance can be adjusted in accordance with the content of the vehicle control, which is to be executed by the host vehicle based on the vehicle data of the other vehicle.

[0111] Examples of vehicle control actions to be performed based on the other vehicle's data include lane changes, left or right turns, following maneuvers, providing information to a driver, and the like. For example, when following maneuvers, a value smaller than that used for lane changes or similar actions can be used as the peripheral distance. The peripheral distance, according to the control action, can be interpreted appropriately. [Modification 3]

[0112] The procedure for determining the communication quality of direct vehicle-to-vehicle communication by the communication quality determination unit F7 is not limited to the procedure described above. If a reception error rate (hereinafter referred to as the "packet loss rate") of the near-field vehicle data packet is calculated for each of the other vehicles, and another vehicle with a packet loss rate greater than or equal to a predetermined threshold is present, it can be determined that the communication quality of the direct vehicle-to-vehicle communication is below the permissible level.

[0113] The packet loss rate for a specific other vehicle can be calculated as follows. First, it is registered when the receiving data management unit... F5 The short-range vehicle data packet can be received from another vehicle; the receiving data management unit F5 a reception time of the short-range vehicle data packet as a reception history in advance in memory M1 More precisely, the storage M1 stores data (hereinafter referred to as "Direct Reception History Data") that shows the reception history for each vehicle.

[0114] If the communication quality determination unit F7 The communication quality determination unit determines whether the long-distance vehicle data packet can be received from another vehicle. F7 The number of times (hereinafter referred to as "the number of successful receptions") that the near-area vehicle data packet, which is sent in the near area by the other vehicle, can be received within the past one second since the long-area vehicle data packet was received, based on the history data of direct reception.

[0115] An expected value (hereinafter referred to as the "receive expectation value") of the number of times the vehicle data packet, sent by another vehicle via direct vehicle-to-vehicle communication, is received in one second is obtained by dividing 1 second by the short-range transmit cycle Td. More precisely, since the short-range transmit cycle Td is set to 0.1 s in this example, the receive expectation value is 10 .

[0116] The number of unsuccessful receptions, which is the number of times the reception of vehicle data packets sent by a specific other vehicle via direct vehicle-to-vehicle communication fails, is obtained by subtracting the number of successful receptions for that specific other vehicle from the expected reception value. Furthermore, the value obtained by dividing the number of unsuccessful receptions for that specific other vehicle by the expected reception value corresponds to the packet loss rate for that other vehicle.

[0117] More precisely, when the long-distance vehicle data packet of a specific other vehicle is captured, the communication quality determination unit determines F7 The number of successful receptions from the history data of direct reception from the other vehicle is calculated, and the communication quality determination unit is determined. F7 The packet loss rate for the other vehicle is calculated based on the specified number of successful receptions and the expected reception value. The packet loss rate can be expressed as a percentage. In this example, the value obtained by dividing the number of unsuccessful receptions by the expected reception value is used as is, without being converted to a percentage.

[0118] If the packet loss rate calculated in this way is less than or equal to a predetermined threshold (such as 0.2), it can be determined that the communication quality is below the permissible level. The threshold (hereinafter referred to as the "loss rate threshold") for determining, based on the packet loss rate, whether the communication quality is greater than or equal to the permissible level, can be set to a value corresponding to a distance between the host vehicle and the other vehicle to be subjected to the determination process. This is because the packet loss rate tends to increase with increasing distance between the vehicles. [Modification 4]

[0119] If the long-distance transmission cycle Tw is based on the determination result of the communication quality determination unit F7 from the first cycle Tw1 on the second cycle Tw2 When set, the communication control unit can 13 , via the wide area network, send a communication packet (hereinafter referred to as the "second cycle request packet") to request the peripheral vehicles to switch the wide area transmission cycle Tw to the second cycle Tw2 to be set. The generation and transmission of the request packet of the second cycle is handled by the wide area communication processing unit. F4 realized.

[0120] The second cycle request packet, processed by the wide area communication processing unit F4 in cooperation with the long-distance communication module 12 is sent through the center 2 transmitted to the peripheral vehicle. For example, when the request packet is received by vehicle Ma in the second cycle, the center identifies it. 2 the peripheral vehicles of vehicle Ma and transmits the center 2 The request packet is sent in the second cycle to the identified peripheral vehicles. If the long-range communication processing unit... F4 every vehicle system 1 Upon receiving the request packet in the second cycle, the wide area communication processing unit (WAN) is activated. F4 the long-distance transmission cycle Tw to the second cycle Tw2 .

[0121] When the long-distance transmission cycle Tw switches to the second cycle Tw2 The second cycle, triggered by the receipt of the request packet, is executed by the wide area communication processing unit. F4 The sending of the request packet in the second cycle does not occur. This is because when the request packet in the second cycle is sent, even if the wide area transmission cycle Tw is set to the second cycle upon receipt of the request packet in the second cycle. Tw2 When set, the request packet is distributed in a chain for the second cycle.

[0122] According to the configuration of modification 4 If the host vehicle determines that the communication quality of the direct vehicle-to-vehicle communication is below the permissible level, the host vehicle can also send the vehicle data packet in the second cycle. Tw2 send to the peripheral vehicle.

[0123] The long-distance communications processing unit F4 The communication packet (hereinafter referred to as the reset permission packet) is sent over the wide area network to reset the wide area transmission cycle Tw to the first cycle. Tw1 to allow, if the communication quality determination unit F7 determines that the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the permissible level after the request packet has been sent in the second cycle.

[0124] When the request packet is received in the second cycle, the wide area communication processing unit registers F4 Information (such as the vehicle ID) indicating a sending source of the communication packet is stored in memory as a request source vehicle beforehand. M1 When the reset permission packets are received from all of the request source vehicles, the long-range communications processing unit sets F4 the long-distance transmission cycle Tw from the second cycle Tw2 on the first cycle Tw1 Back. Incidentally, there is a high probability that some of the source vehicles of the second-cycle request packets, which subsequently failed to receive the long-range vehicle data packets, are no longer peripheral vehicles for the host vehicle. Therefore, vehicles that can no longer receive the long-range vehicle data packets can be removed from the registry as source vehicles. [Modification 5]

[0125] In the above embodiment, the mode in which the second cycle Tw2 to the same value as the short-range transmission cycle Td The following is set as an example. However, the present invention is not limited to the above configuration. As in Fig. As shown in section 6, the second cycle can begin. Tw2 for example, twice as long as the short-range transmission cycle Td be. Furthermore, as in Fig. 7 shown, the second cycle Tw2 half as long as the short-range transmission cycle Td. More precisely, the second cycle. Tw2 can be set to be shorter than the near-field transmission cycle Td to be. In this case, the generation cycle can Tg to a value equal to the second cycle Tw2 be set.

[0126] Furthermore, the long-distance vehicle data package can be generated to transmit the same vehicle data as the short-distance vehicle data package, and, if a constraint for the long-distance vehicle data package is met, the first cycle can be Tw1 and the second cycle Tw2 , which is known as the long-distance transmission cycle Tw can be used, not necessarily integer multiples of the short-range transmission cycle. Td be. As in Fig. As shown in section 8, the first cycle can Tw1 for example, 8.5 times the short-range transmission cycle Td be set. In this case, this can be done by the wide area communication processing unit. F4 The vehicle data packet sent at time Tb contains the vehicle data that is housed in the vehicle data packet that is processed by the short-range communication processing unit. F3 shortly before the vehicle data packet is sent. This means the vehicle data packet only needs to contain the vehicle data generated at a specific time point Ta. [Modification 6]

[0127] The above description describes the mode in which the long-range communication module operates. 12 and the communication control unit 13 are housed in the same casing, as illustrated. However, the present invention is not limited to the above configuration. As shown in Fig. As shown in Figure 9, the long-distance communication module can 12 outside the communication unit 10 It is intended that the communication control unit 13 features, and can use the long-distance communication module 12 and the communication control unit 13 They should be designed to be connected to each other via a LAN.

[0128] Furthermore, the short-range communication module 11 outside the communication unit 10 It is intended that the communication control unit 13 features, and can use the short-range communication module 11 and the communication control unit 13 They should be designed to be connected to each other via the LAN.

[0129] Furthermore, as in Fig. 10 shown, both the short-range communication module 11 as well as the long-distance communication module 12 outside the unit 10A It is intended that the communication control unit 13 exhibits. More precisely, both the short-range communication module 11 as well as the long-distance communication module 12 can be designed to communicate with the communication control unit via the LAN 13 to be connected. [Modification 7]

[0130] The above description describes the mode in which the wide area communication processing unit operates. F4 The long-range transmission cycle changes based on the presence or absence of the peripheral vehicle and the communication quality of the current direct vehicle-to-vehicle communication, as illustrated. However, the present invention is not limited to the above configuration. If, based on a certain type of peripheral vehicle and the structure of a road on which the host vehicle is traveling, it is estimated that the communication quality of the direct vehicle-to-vehicle communication will fall below the permissible level (i.e., decrease) before the vehicle travels a predetermined distance or within a predetermined time, the long-range transmission cycle Tw is preferably switched to the second cycle in advance. Tw2 set. Such a mode is a modification. 7 designated. The modification 7 This can be implemented, for example, as follows.

[0131] As in Fig. As shown in 11, the communication control unit 13 according to modification 7 a communication quality assessment unit F8 in addition to the various functions described above. The communication quality assessment unit F8 This can be achieved by allowing a CPU to execute a communication control program, or it can be implemented in hardware using one or more integrated circuits or the like. A function corresponding to the communication quality estimation unit. F8 can be found in the communication quality determination unit F7 be provided.

[0132] The communication quality assessment unit F8 This is a functional block for estimating whether or not the communication quality of direct vehicle-to-vehicle communication will fall below the permissible level from now on. The condition for this is the communication quality estimation unit. F8 To enable the determination that the communication quality of direct vehicle-to-vehicle communication will decrease from now on, can be determined or interpreted in a suitable manner.

[0133] The communication quality assessment unit F8 For example, it determines that communication quality will decrease from now on if it is estimated that a large vehicle, such as a LKW The host vehicle will overtake the larger vehicle within a fixed time period (such as 7 seconds) from the current time. This is because shadowing is expected to occur while the larger vehicle is overtaking the host vehicle.

[0134] Meanwhile, the other vehicle passing the host vehicle, the other vehicle behind the host vehicle, and the vehicle traveling at a higher speed than the host vehicle are among the peripheral vehicles. By referencing the peripheral vehicle data, the communication quality estimator can be determined. F8 Determine the other vehicle that will soon overtake the host vehicle. If the vehicle data includes the vehicle type of the transmitting source vehicle (specifically, whether or not the vehicle type is a large vehicle, etc.), the communication quality estimator can F8 Determine the vehicle type of the other vehicle that will soon overtake the host vehicle, using the vehicle data of the other vehicle.

[0135] More precisely, if the vehicle data includes the type of transmitting vehicle, the communication quality estimator can F8 estimate whether or not the large vehicle, such as a LKW The time required to overtake the host vehicle is determined by referencing peripheral vehicle data. An overtaking time for the host vehicle can be obtained by dividing the vehicle-to-vehicle distance between the host vehicle and the other vehicle by the relative speed of the other vehicle to the host vehicle.

[0136] Furthermore, the communication quality estimation unit can F8 Determine that the communication quality of direct vehicle-to-vehicle communication will now degrade if there is a section of road (such as a large road bump) with poor visibility in front of the host vehicle. This is because, if the road bump is large, an area may occur where the vehicle data packet sent at close range does not arrive (i.e., a blind spot for direct vehicle-to-vehicle communication).

[0137] The distance considered "in front of the host vehicle" can be a fixed value or dynamically determined according to the host vehicle's speed. A greater distance can be considered "in front of the host vehicle" if the speed is higher.

[0138] Information to determine whether or not the road section with poor visibility is present in front of the host vehicle can be obtained from the position transmitter. 30 be provided. That is, the position transmitter. 30 is designed to sequentially transmit information (hereinafter referred to as "ahead road information") to the communication control unit 13 to provide information that displays the road structure in front of the host vehicle. The road section with poor visibility among the various roads can be pre-registered on a road map. Furthermore, the communication quality estimation unit can be used. F8 Determine whether or not the road in front of the host vehicle is a poor visibility road by referring to a road gradient displayed as a road feature or similar. The communication quality estimator. F8 For example, it can determine that a section where the amount of change in the road gradient within a certain distance (such as 50 m) is greater than or equal to a predetermined angle (such as 30 degrees) is a section of road with poor visibility.

[0139] The long-distance communications processing unit F4 according to modification 7 sets the long-distance transmission cycle Tw to the second cycle Tw2 , if the communication quality estimation unit F8 This determines that the communication quality decreases. According to such a mode, since the long-distance transmission cycle Tw is on the second cycle Tw2 This allows the real-time capability of communication between the vehicles to be maintained before the communication quality actually falls below the predetermined permissible level.

[0140] It is noted that a flowchart or the execution of the flowchart in the present application has sections (also referred to as steps), each of which is, for example, described as S1 are designated. Furthermore, each section can be divided into several subsections, while several sections can be combined into a single section. Furthermore, each of the sections configured in this way can also be designated as a device, a module, or a means or facility.

[0141] Although the present invention is described above in connection with its embodiments, it should be noted that it is not limited to these embodiments and constructions. The present invention is to be understood as encompassing various modifications and equivalent arrangements. Furthermore, although the various combinations and configurations are shown, other combinations and configurations comprising more, fewer, or only a single element are likewise to be understood as included within the scope of protection of the present invention. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2016055975

[0001] JP 2013005186 A

[0006]

Claims

[1] Communication control device for a vehicle, with: - a short-range communication processing unit (F3) that performs direct vehicle-to-vehicle communication, which is direct vehicle-to-vehicle communication without passing through a long-range communication network, with a peripheral vehicle arranged around the vehicle, in cooperation with a short-range communication module to perform direct wireless communication with an external device without passing through the long-range communication network; - a long-range communication processing unit (F4) that performs indirect vehicle-to-vehicle communication, which is indirect vehicle-to-vehicle communication that traverses the long-range communication network, with the peripheral vehicle in cooperation with a long-range communication module for wireless communication with the external device via the long-range communication network; - a vehicle data generation unit (F2) that generates vehicle data indicating the vehicle's driving condition based on a reading from a sensor attached to the vehicle; and - a communication quality determination unit (F7) that determines whether the communication quality of the direct vehicle-to-vehicle communication provided by the short-range communication processing unit is greater than or equal to a predetermined permissible level, wherein - the short-range communication processing unit wirelessly transmits a communication packet containing the vehicle data in a predetermined short-range transmission cycle from the short-range communication module, - the long-range communication processing unit executes a process to send the communication packet containing the vehicle data to the peripheral vehicle in a predetermined long-range transmission cycle via the long-range communication module and the long-range communication network, - the long-range communication processing unit selects a predetermined first long-range transmit cycle that is longer than the short-range transmit cycle when the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the predetermined allowable level; and - the long-range communication processing unit selects a predetermined second long-range transmit cycle, less than or equal to the short-range transmit cycle, as the long-range transmit cycle when the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is below the predetermined permissible level. [2] Communication control device according to claim 1, characterized by , that it further exhibits: - a peripheral vehicle identification unit (F6) that determines whether another vehicle corresponding to the peripheral vehicle is present within a predetermined area of ​​the vehicle, based on the vehicle data acquired by the short-range communication processing unit and the long-range communication processing unit, wherein - the long-range communication processing unit selects the second long-range transmission cycle as the long-range transmission cycle when the peripheral vehicle determination unit determines that the other vehicle is located within the predetermined area according to the peripheral vehicle, and the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is below the predetermined permissible level. [3] Communication control device according to claim 2, characterized by , that - the long-range communication processing unit selects the first long-range transmission cycle as the long-range transmission cycle when the peripheral vehicle determination unit determines that no other vehicle corresponding to the peripheral vehicle is located within the predetermined area. [4] Communication control device according to any one of claims 1 to 3, characterized by, that it further exhibits: - a communication quality estimation unit (F8) that estimates whether the communication quality of the direct vehicle-to-vehicle communication deteriorates until the vehicle has traveled a predetermined distance from a current position or within a predetermined time period, based on vehicle data acquired by the short-range communication processing unit and the long-range communication processing unit, or based on a structure of a road ahead of the vehicle, wherein - the long-range communication processing unit selects the second long-range transmission cycle as the long-range transmission cycle when the communication quality estimation unit estimates that the communication quality of the direct vehicle-to-vehicle communication is deteriorating. [5] Communication control device according to any one of claims 1 to 4, characterized by , that - the long-range communication processing unit sends a second-cycle request packet, which is a communication packet to request the peripheral vehicle to set the long-range transmission cycle to the second long-range transmission cycle, via indirect vehicle-to-vehicle communication to the peripheral vehicle when the long-range communication processing unit changes the long-range transmission cycle from the first long-range transmission cycle to the second long-range transmission cycle, based on a determination by the communication quality determination unit that the communication quality of the direct vehicle-to-vehicle communication is below the predetermined permissible level. [6] Communication control device according to claim 5, characterized by , that - the long-range communication processing unit sets the long-range transmission cycle to the second long-range transmission cycle when the long-range communication processing unit receives the second cycle request packet via indirect vehicle-to-vehicle communication. [7] Communication control device according to claim 6, characterized by , that - the long-range communication processing unit sends a reset permission packet as a communication packet to allow the long-range transmission cycle to be reset to the first long-range transmission cycle when the communication quality determination unit determines that the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the allowable level after the request packet of the second cycle has been sent. [8] Communication control device according to claim 7, characterized by , that - the long-range communication processing unit sets the long-range transmission cycle to the first long-range transmission cycle when the reset permission packet is received by all vehicles according to the transmission sources of the received request packet second cycle, in a case where the long-range transmission cycle is set to the second long-range transmission cycle based on a reception of the request packet second cycle. [9] Communication control device according to any one of claims 1 to 8, characterized by , that - The communication quality determination unit determines whether the communication quality of the direct vehicle-to-vehicle communication is greater than or equal to the predetermined permissible level by referring to a received signal strength or a packet loss rate of the communication packet sent by the peripheral vehicle and received by the direct vehicle-to-vehicle communication. [10] Communication control device according to any one of claims 1 to 9, characterized by , that - the vehicle data includes position information, which shows the current position, speed and direction of travel of the vehicle, and the time of generation at which the vehicle data is generated.