JP2007196971A - On-vehicle communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accomplish a suitable on-vehicle communication system for increasingly providing electric equipment on a vehicle such as an automobile. <P>SOLUTION: The on-vehicle communication system is provided with a CAN bus 16 connected with a plurality of controllers 10, 12, 14 mounted in the automobile; a metal cable communication passage 22 connected with increasingly provided controllers 18, 20 attached in the automobile later; and an inter-network communication device 24 for relaying the CAN bus 16 and the metal cable communication passage 22. The inter-network communication device 24 selects control information having ID for CAN previously determined relevant to the increasingly provided controllers 18, 20 of the control information going back and forth the CAN bus 16, converts the CAN ID of the selected control information to metal cable ID and transmits it to the metal cable communication passage 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication system for controlling electrical equipment mounted on a vehicle such as an automobile.

  As a communication system for controlling electrical equipment mounted on a vehicle typified by an automobile, an engine control device, a brake control device, an air conditioner control device, and the like connected to a main communication path are known. In this communication system, control information (for example, a control signal and a sensor signal) is exchanged between control devices, and each control device is controlled based on the received control information and externally input information.

  In such a communication system, CAN (Controller Area Network), LIN (Local Interconnect Network), or the like is applied as a communication protocol for exchanging control information. For example, a plurality of control devices are connected to a dedicated communication line (hereinafter referred to as a CAN bus) as a main communication path. Then, when a certain control device transmits control information to the CAN bus, the other control device acquires control information necessary for itself among the control information traveling on the CAN bus, and uses the acquired information to select the target device. Control is performed (for example, refer patent document 1).

Japanese Patent Laid-Open No. 10-24783

  By the way, electrical equipment (for example, a navigation device) that can be added to a vehicle has been developed one after another. In a method such as Patent Document 1, when such an extension device is newly installed in a vehicle, the extension device is connected to an existing CAN bus. However, due to the control information transmitted from the extension device. The amount of communication on the CAN bus may increase. In that case, there is a possibility that the signal transmission time of the CAN bus is increased and the responsiveness of each electrical equipment is impaired, and there is a possibility that a signal collision occurs frequently on the CAN bus and the control of each electrical equipment is delayed.

  An object of the present invention is to realize a more suitable in-vehicle communication system by adding electrical equipment to a vehicle such as an automobile.

  In order to solve the above problems, an in-vehicle communication system according to the present invention includes a main communication path to which a control device mounted on a vehicle is connected, an expansion communication path to which a control device is added to the vehicle, and the main communication path. And a communication device that relays between the expansion communication path, and the communication apparatus has a predetermined identifier corresponding to the control device of the expansion communication path among the control information passing through the main communication path Control information is selected, and the selected control information is transferred to the expansion communication path.

  That is, when a control device is added to a vehicle such as an automobile, the extension device is connected to an extension communication path different from the main communication path. The communication device interposed between the main communication path and the expansion communication path passes only the signals necessary for controlling the expansion device among the signals on the main communication path to the expansion communication path, and other signals. Will be blocked. Here, the other signals include signals from the expansion communication path to the main communication path.

  In this way, even when a control device is added to the vehicle, it is possible to prevent the signal of the extension communication path from entering the main communication path in a random manner, and thus it is possible to suppress an increase in the communication amount of the main communication path. . As a result, the responsiveness of each control device can be ensured, and the control delay due to signal collision in the main communication path can be avoided, thereby improving the reliability of the communication system.

  Here, the communication device preferably collates priorities given in advance to the control information after selection, and transfers the selection information in descending order of the priorities. Thereby, the responsiveness of a specific control apparatus can be improved according to an individual concrete actual condition.

  According to a more specific aspect, the communication device has an identifier conversion table in which an identifier for communication on the main communication path and an identifier for communication on the expansion communication path are associated and registered. And selecting control information having an identifier registered in the identifier conversion table from among the control information passing through the main communication path, and transferring the selection information according to the identifier conversion table when transferring the selection information. The identifier on the communication path is converted into the identifier on the extension communication path.

  In addition, the communication device has a priority conversion table in which a priority when communicating on the main communication path and a priority when communicating on the expansion communication path are associated and registered, and the selection information is transferred In this case, it is desirable to convert the priority of the selection information in the main communication path into the priority in the extension communication path according to the priority conversion table. That is, when passing the control information, the communication device converts the priority of the control information in addition to converting the identifier of the control information. Thereby, since a priority can be changed for every communication path according to a situation concretely, fine control according to a user's preference is realizable.

  In addition, the communication device includes a detection circuit that monitors a communication state of the extension communication path and detects that the selection information after the transfer collides with other control information in the extension communication path, The detection circuit preferably retransmits the selection information when the collision is detected. As a result, since loss of control information due to signal collision in the extension communication path is avoided, the control information can surely reach the control device, thereby improving the reliability of the communication system.

  Further, the communication device selects control information having a predetermined identifier corresponding to the control device of the main communication path from among the control information passing through the expansion communication path, and the selected control information is selected from the main communication path. It is desirable to transfer to the communication path. As a result, it is possible to pass only signals necessary for controlling the control device of the main communication path to the main communication path among the signals of the expansion communication path while suppressing an increase in the communication amount of the main communication path. That is, only necessary control information is exchanged between the main communication path and the extension communication path.

  Moreover, it is preferable to apply a battery line for supplying power to the devices mounted on the vehicle as the additional communication path.

  ADVANTAGE OF THE INVENTION According to this invention, a more suitable vehicle-mounted communication system is realizable by adding an electrical equipment to vehicles, such as a motor vehicle.

(First embodiment)
A first embodiment of an in-vehicle communication system to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of an in-vehicle communication system according to the present embodiment. In addition, although the example which adds a control apparatus to a motor vehicle is demonstrated, this invention is applicable also to other vehicles, such as a train.

  As shown in FIG. 1, the in-vehicle communication system includes a CAN bus 16 as a main communication path to which a plurality of control devices 10, 12, and 14 mounted on a vehicle are connected, and additional control devices 18 and 20 that are retrofitted to the vehicle. A metal cable communication path 22 as an additional communication path connected, and an inter-network communication device 24 that relays between the CAN bus 16 and the metal cable communication path 22 are provided.

  Here, the inter-network communication device 24 according to the present embodiment has a predetermined identifier (ID) corresponding to the expansion control devices 18 and 20 among the control information (for example, control signal, sensor signal) that passes through the CAN bus 16. Is selected, and the selected control information is transferred to the metal cable communication path 22.

  That is, in this embodiment, when retrofitting the extension control devices 18 and 20 to the automobile, the extension control devices 18 and 20 are connected to a metal cable communication path 22 that is different from the CAN bus 16. When controlling the extension control devices 18 and 20, the inter-network communication device 24 sends only signals necessary for controlling the extension control devices 18 and 20 to the metal cable communication path 22 among signals on the CAN bus 16. Passing and blocking the passage of other signals. The other signals include signals from the metal cable communication path 22 toward the CAN bus 16.

  In this way, even when the extension control devices 18 and 20 are newly installed in the automobile, signals on the metal cable communication path 22 can be prevented from entering the CAN bus 16 at random. An increase in the amount can be suppressed. As a result, even when the extension control devices 18 and 20 are controlled using the control information of the control devices 10, 12, and 14, the responsiveness of the control devices 10, 12, and 14 can be secured, and the signal on the CAN bus 16 can be secured. The reliability of the control communication system is improved, for example, the control delay caused by the collision can be avoided.

  In more detail, the in-vehicle communication system of the present embodiment will be described. As shown in FIG. 1, the in-vehicle communication system is roughly divided into a CAN bus communication system and a metal cable communication system.

  In the CAN bus communication system, control devices 10, 12, and 14 are connected via a CAN bus 16 so that they can communicate with each other. The control device 10 is, for example, an engine control device mounted with an electronic control unit (hereinafter referred to as ECU) 26 and connected to the CAN bus 16 via the CAN transceiver 28. The ECU 26 outputs, for example, an on / off command or the like to the control device 10 based on control information input via the CAN transceiver 28 or input information from the outside, or transmits control information to the CAN bus 16 via the CAN transceiver 28. To do. The control device 12 is, for example, a brake control device mounted with the ECU 30 and connected to the CAN bus 16 via the CAN transceiver 32. The control device 14 is, for example, an air conditioner control device that includes the ECU 34 and is connected to the CAN bus 16 via the CAN transceiver 36. As the control devices 10, 12, and 14 here, control devices such as lights, door locks, and electric mirrors may be applied.

  Each ECU 26, 30, 34 connected to the CAN bus 16 is assigned a unique CAN identifier (hereinafter referred to as a CAN ID as appropriate) for CAN communication. The ECUs 26, 30, and 34 share the CAN ID and the correspondence table of the ECU, and discriminate the ECU that is the transmission source of the reception signal by checking the CAN ID of the reception signal with the correspondence table. For example, based on the determination result of the transmission source ECU, the ECU 26 captures only a signal necessary for its own control processing, and outputs a control command to the control device 10 using the captured signal. The same applies to the ECUs 30 and 34. It is assumed that each ECU 26, 30, and 34 is preset with the ID of the transmission source ECU of the signal that it should capture.

  FIG. 3 is a diagram showing the data format of the CAN communication protocol. As shown in FIG. 3, the CAN communication signal includes a start bit 58, a CAN ID 60, an RTR 62, a control 64, data 66, an error correction 68, an ACK 70, an end bit 72, and an intermission 74. Concatenated.

  On the other hand, in the metal cable communication system, the extension control devices 18 and 20 are connected via a metal cable communication path 22 so as to communicate with each other. The extension control device 18 is, for example, a navigation system in which an extension ECU 38 is mounted and connected to the metal cable communication path 22 via the extension transceiver 40. The extension control device 20 is, for example, a fog lamp that includes the extension ECU 42 and is connected to the metal cable communication path 22 via the extension transceiver 44.

  Further, each of the ECUs 38 and 42 connected to the metal cable communication path 22 is assigned a unique metal cable identifier (hereinafter, appropriately referred to as a metal cable ID) for performing metal cable communication. The ECUs 38 and 42 share the metal cable ID and the correspondence table of the ECU, and collate the metal cable ID of the reception signal with the correspondence table to determine the ECU that is the transmission source of the reception signal. Then, for example, based on the determination result of the transmission source ECU, the ECU 38 captures only a signal necessary for its own control processing, and outputs a control command to the extension control device 18 using the captured signal. The same applies to the ECU 42. In addition, each ECU38,42 shall set ID of the transmission origin ECU of the signal which self should take in beforehand.

  The data format of the metal cable communication signal is basically the same as that of the CAN communication signal except that a metal cable ID is assigned instead of the CAN ID 60 of FIG. However, regarding the communication protocol of the metal cable communication path 22, the communication protocol of the CAN bus 16 may be applied, or a communication protocol different from the communication protocol of the CAN bus 16 may be applied.

  In this embodiment, an inter-network communication device 24 is interposed between the CAN bus communication system and the metal cable communication system. FIG. 2 is a diagram illustrating a configuration of the inter-network communication device 24. As shown in FIG. 2, the inter-network communication device 24 includes a CAN receiving unit 46, an ID selection circuit 48, a memory 50, a bit string generation circuit 52, a carrier sense circuit 54, a transmitter 56, and the like. .

  The CAN receiver 46 receives all signals that travel on the CAN bus 16. The CAN receiver 46 outputs the CAN ID included in the received signal to the ID selection circuit 48 and outputs data other than the CAN ID included in the received signal to the bit string generation circuit 52.

  The ID selection circuit 48 has a lookup table as an identifier conversion table. FIG. 4 is an example of a lookup table. As shown in FIG. 4, in the lookup table, for example, the CAN ID “0001” assigned to the ECU 26 is associated with the metal cable ID “0003” for communicating the control information of the ECU 26 through the metal cable communication path 22. Registered. That is, the CAN ID in the lookup table is used to output signals (for example, switch information and ignition information) necessary for controlling the extension control devices 18 and 20 among the CAN IDs of the control devices 10, 12, and 14. This is the CAN ID for the control devices 10, 12, 14. The metal cable ID in the lookup table is set so as not to overlap with the metal cable ID of the extension control devices 18 and 20. The CAN ID or metal cable ID in the lookup table is registered when the expansion control devices 18 and 20 are installed, and is corrected according to changes in the control device 10 and the expansion control device 18 and the like.

  In the lookup table, the priority is registered corresponding to the CAN ID. The priority shown in FIG. 4 is an importance for determining the transmission order of signals in the metal cable communication path 22 and is an index for determining a signal to be transmitted with priority when signals collide on the metal cable communication path 22. It is. The priority can be individually changed in association with the transmission bit string. Further, the priority value is relatively determined among the extension control device 18, the extension control device 20, and the inter-network communication device 24 when the lookup table is registered or corrected.

  The ID selection circuit 48 collates the CAN ID output from the CAN receiver 46 with a lookup table. Next, when the CAN ID is already registered in the lookup table, the ID selection circuit 48 determines that the signal corresponding to the CAN ID should be transmitted to the metal cable communication path 22. Then, the ID selection circuit 48 converts the CAN ID “0001” into the metal cable ID “0003” according to the lookup table, and outputs the converted metal cable ID to the bit string generation circuit 52. The ID selection circuit 48 outputs the priority “1” corresponding to the CAN ID “0001” to the memory 50 and the transmitter 56 according to the lookup table.

  The bit string generation circuit 52 receives data other than the CAN ID output from the CAN receiver 46 and the metal cable ID output from the ID selection circuit 48. Next, the bit string generation circuit 52 converts the received information into a transmission format for a metal cable. For example, when the CAN bus 16 communication protocol is applied to the metal cable communication path 22, the bit string generation circuit 52 replaces the CAN ID 60 in FIG. 3 with the metal cable ID and recalculates the error correction 68 data. Then, the control information for transmission is generated by converting to the transmission format for the metal cable. Then, the bit string generation circuit 52 outputs the generated control information to the memory 50 and the transmitter 56.

  The carrier sense circuit 54 confirms the communication state of the metal cable communication path 22 and outputs it to the transmitter 56. For example, the carrier sense circuit 54 outputs a standby command to the transmitter 56 when the extension control device 18 and the extension control device 20 are communicating. On the other hand, the carrier sense circuit 54 outputs a permission command to the transmitter 56 when the extension control device 18 and the extension control device 20 are not communicating.

  The transmitter 56 receives the control information output from the bit string generation circuit 52 and the priority output from the ID selection circuit 48, and the metal cable communication path 22 according to the priority and the output command of the carrier sense circuit 54. Send control information to. For example, when a permission command is output from the carrier sense circuit 54, the transmitter 56 transmits control information to the metal cable communication path 22. On the other hand, when the standby command is output from the carrier sense circuit 54, the transmitter 56 stops or waits for transmission of the control information, and when waiting, the transmitter 56 retransmits the control information according to the output of the permission command. Furthermore, when a plurality of control information to be transmitted is selected, the transmitter 56 collates priorities given in advance to each control information, and transmits the control information to the metal cable communication path 22 in descending order of priority. The transmitter 56 transmits the control information to be transmitted when the control information passes over the metal cable communication path 22 and the priority of the transmission target is higher than the control information on the metal cable communication path 22. When the priority of the control information to be transmitted is lower than the control information on the metal cable communication path 22, the transmission of the control information is stopped or waited.

  The transmitter 56 may read the control information stored in the memory 50 instead of the control information from the bit string generation circuit 52 and the ID selection circuit 48 when outputting the control information. Here, when a plurality of control information is stored in the memory 50, the transmitter 56 reads the control information from the memory 50 in descending order of priority, and transmits the control information to the metal cable communication path 22 in the read order.

  The transmitter 56 includes a transmission amplifier that amplifies the voltage of the signal output from the bit string generation circuit 52. In addition, a means for phase modulation, amplitude modulation, OFDM, or spread spectrum modulation may be disposed in front of the transmission amplifier. In addition, a band pass filter that allows only the set band of all the signal bands to pass may be attached to the front stage or the rear stage of the transmission amplifier. Further, since it is necessary to store a plurality of data in the memory 50, it is desirable to apply a dual port memory in which the input port and the output port are separately mounted as the memory 50.

  The in-vehicle communication system configured as described above will be described more specifically with reference to FIGS.

<Example 1>
The present embodiment is an example in which a fog lamp and a fog lamp switch are added in an automobile. FIG. 5 is a diagram illustrating a configuration of the in-vehicle communication system according to the present embodiment. FIG. 6 is a diagram for explaining the operation of the fog lamp. FIG. 7 is a diagram illustrating a lookup table according to the present embodiment.

  As shown in FIG. 5, the in-vehicle communication system of this embodiment includes an engine 76 and an optical sensor 78 that are connected to each other via a CAN bus 16, and a fog lamp 80 that is connected to each other via a metal cable communication path 22. And a fog lamp switch 84 and the like. 5 is compared with that of FIG. 1, the engine 76 corresponds to the control device 10, the optical sensor 78 corresponds to the control device 12, the fog lamp 80 corresponds to the additional control device 20, and the fog lamp switch 84 is This corresponds to the extension control device 18. As in the case of FIG. 1, an inter-network communication device 24 that relays the CAN bus 16 and the metal cable communication path 22 is provided.

  The fog lamp 80 is mounted with a fog lamp ECU 82 and connected to the metal cable communication path 22 via the extension transceiver 44. The fog lamp switch 84 is mounted with a fog lamp switch ECU 86 and is connected to the metal cable communication path 22 via the extension transceiver 40.

  The fog lamp ECU 82 outputs a lighting command to the fog lamp 80 in accordance with the ON signal transmitted from the fog lamp switch ECU 86, and outputs a lighting stop command to the fog lamp 80 in response to the external light signal transmitted from the optical sensor 78. It shall have. That is, as shown in FIG. 6, the lighting condition of the fog lamp 80 is when the control information transmitted from the fog lamp switch ECU 86 includes an ON signal and the control information transmitted from the ECU 30 of the optical sensor 78 also includes an ON signal. is there. Note that the ON signal of the optical sensor 78 is output when there is no external light.

  That is, the fog lamp ECU 82 needs control information for the optical sensor 78 connected to the CAN bus 16 in addition to the control information for the fog lamp switch 84 when controlling the lighting or extinguishing of the fog lamp 80. Therefore, the fog lamp ECU 82 takes in the control information of the fog lamp switch 84 and acquires the control information of the optical sensor 78 via the inter-network communication device 24.

  More specifically, first, when the fog lamp switch 84 is turned on, the fog lamp switch ECU 86 transmits its own metal cable ID and ON signal to the metal cable communication path 22 as control information. The fog lamp ECU 82 receives the control information of the fog lamp switch 84, and sets the fog lamp switch flag to “1” when the ON information is included in the control information.

  When attention is paid to the CAN bus 16, control information transmitted from the ECU 30 of the optical sensor 78 and control information transmitted from the ECU 26 of the engine 76 are mixed. Here, the CAN ID of the ECU 30 is “0007”, and the CAN ID of the ECU 26 is “0004”. The inter-network communication device 24 receives all of the control information that passes on the CAN bus 16 by the CAN receiver 46 and outputs the CAN ID included in each received signal to the ID selection circuit 48. In the lookup table of the ID selection circuit 48, as shown in FIG. 7, the CAN ID “0007”, the metal cable ID “0017”, and the priority “2” are associated. The look-up table is created when the fog lamp 80 is added to the automobile.

  The ID selection circuit 48 of the inter-network communication device 24 outputs a process cancel command related to the control information to the bit string generation circuit 52 because the control information having the CAN ID “0004” is not registered in the lookup table. That is, since the control information of the engine 76 is not necessary for controlling the fog lamp 80, transmission from the CAN bus 16 to the metal cable communication path 22 is stopped by the inter-network communication device 24.

  On the other hand, the ID selection circuit 48 converts the CAN ID “0007” into the metal cable ID “0017” because the control information having the CAN ID “0007” is already registered in the lookup table. The subsequent ID is output to the bit string generation circuit 52 together with a processing command related to control information. Next, the bit string generation circuit 52 generates a bit string based on the signal output from the ID selection circuit 48. The generated bit string is transmitted to the metal cable communication path 22 by the transmitter 56. That is, since the control information of the optical sensor 78 is necessary for controlling the fog lamp 80, it is transferred from the CAN bus 16 to the metal cable communication path 22 by the inter-network communication device 24. The transferred control information of the optical sensor 78 is taken into the fog lamp ECU 82 in the process of moving over the metal cable communication path 22. The ECU 82 sets the optical sensor flag of FIG. 6 to “1” when the ON signal is included in the control information of the optical sensor 78. Then, the fog lamp ECU 82 lights the fog lamp 80 when both the fog lamp switch flag and the optical sensor flag in FIG. 6 are “1”.

<Example 2>
The present embodiment is an example in which a navigation system and a navigation controller are added in an automobile. FIG. 8 is a diagram illustrating a configuration of the in-vehicle communication system according to the present embodiment.

  As shown in FIG. 8, the in-vehicle communication system according to the present embodiment includes an engine 76 and a vehicle speed sensor 79 connected to each other via a CAN bus 16 and a navigation system connected to each other via a metal cable communication path 22. 90, a navigation system controller 94, and the like. The navigation system 90 is equipped with a navigation system ECU 92 and is connected to the metal cable communication path 22 via the additional transceiver 44. The navigation system controller 94 is equipped with a navigation system controller ECU 96 and is connected to the metal cable communication path 22 via the extension transceiver 40. An inter-network communication device 24 is disposed between the CAN bus 16 and the metal cable communication path 22.

  In the present embodiment, as in the case of the first embodiment, the control information of the engine 76 is not necessary for the control of the navigation system 90. Therefore, the inter-network communication device 24 connects the CAN cable 16 to the metal cable communication path 22. Transmission to is canceled. On the other hand, since the control information of the vehicle speed sensor 79 is necessary for control of the navigation system 90, it is transferred from the CAN bus 16 to the metal cable communication path 22 by the inter-network communication device 24. The navigation system 90 is controlled by the navigation system ECU 92 based on the control information transferred from the inter-network communication device 24 and the control information transmitted from the navigation system controller 94.

<Example 3>
In this embodiment, when the control information on the CAN bus 16 is transferred to the metal cable communication path 22, the CAN ID of the control information is converted into the metal cable ID, and the priority is reset. FIG. 9 is a diagram illustrating a configuration of the in-vehicle communication system according to the present embodiment. FIG. 10 is a diagram showing a lookup table implemented in the inter-network communication device 24 of FIG.

  As shown in FIG. 9, the in-vehicle communication system of this embodiment includes an engine 76, a vehicle speed sensor 79, and an engine speed sensor 98 that are connected to each other via a CAN bus 16, and a metal cable communication path 22. A navigation system 90, a storage device 100, and the like. The storage device 100 is mounted with a storage device ECU 102 and connected to the metal cable communication path 22 via the additional transceiver 40.

  The storage device 100 acquires and stores, for example, engine speed information via the network communication device 24. The engine speed information is acquired by the engine speed sensor 98. Further, the navigation system 90 acquires, for example, vehicle travel speed information via the inter-network communication device 24, and corrects the position of the vehicle on the navigation map based on the vehicle travel speed information. The vehicle travel speed information is acquired by the vehicle speed sensor 79.

  Here, the inter-network communication device 24 of this embodiment holds the lookup table shown in FIG. As shown in FIG. 10, the look-up table includes a CAN ID “0006” of the engine speed sensor ECU 34, a CAN priority “1”, and a metal cable ID “0039” of the engine speed sensor ECU 34. Metal cable priority “5” is associated. The lookup table associates the CAN ID “0023” of the vehicle speed sensor ECU 30, the CAN priority “3”, the metal cable ID “0010” of the vehicle speed sensor ECU 30, and the metal cable priority “1”. It has been. Although the CAN priority in the lookup table may be unregistered, it is assumed that it is registered as shown in FIG. 10 for convenience of explanation. Also, the highest priority is “1”, and the importance decreases as the value increases.

  That is, in the CAN bus 16, since the engine speed information of the engine speed sensor 98 is used for controlling the engine 76, a high priority “1” is set on the CAN bus 16. When the inter-network communication device 24 receives such engine speed information, the inter-network communication device 24 converts the engine speed information having the CAN ID “0006” into the metal cable ID “0039”. The CAN priority “1” is reset to the metal cable priority “5” and transferred to the metal cable communication path 22. The vehicle traveling speed information of the vehicle speed sensor 79 is set with a priority “3” lower than the engine speed information. Similarly, when such vehicle traveling speed information is transferred from the CAN bus 16 to the metal cable communication path 22 by the inter-network communication device 24, the CAN ID “0023” is converted to the metal cable ID “0010”. At the same time, the CAN priority “3” is reset to the metal cable priority “1”.

  That is, since the navigation system 90 is required to correct the vehicle position on the navigation map with high accuracy, it is necessary to acquire the vehicle travel speed information of the vehicle speed sensor 79 in real time, for example. On the other hand, when storing the engine speed information of the engine speed sensor 98, the storage device 100 is not required to be more immediate than the navigation system 90. Based on such specific circumstances, the inter-network communication device 24 of the present embodiment, when transferring the vehicle travel speed information and the engine speed information from the CAN bus 16 to the metal cable communication path 22, By resetting the priority “3” to the priority “1” and resetting the priority “1” of the engine speed information to the priority “5”, the vehicle running speed information is more than the engine speed information. Is transferred to the metal cable communication path 22 at a higher priority. Therefore, since the vehicle traveling speed information quickly reaches the navigation system 90, the real-time property of the control of the navigation system 90 can be ensured.

<Example 4>
FIG. 11 is a diagram illustrating another example of the inter-network communication device 24 of FIG. As shown in FIG. 11, the inter-network communication device 24 of the present embodiment is provided with a collision detection circuit 104 in place of the carrier sense circuit 54 of FIG. For convenience of explanation, it is assumed that the transmitter 56 in FIG. 11 transmits the control information of the output from the bit string generation circuit 52 without referring to the priority when transferring the control information to the metal cable communication path 22.

  When the control information is transmitted from the transmitter 56 to the metal cable communication path 22, the collision detection circuit 104 generates a signal collision due to superimposition of the transmission timing and the communication timing between the extension control devices 18 and 20. The collision is detected and notified to the transmitter 56 as signal collision information. When the signal collision information is notified from the collision detection circuit 104, the transmitter 56 retransmits the control information. Thereby, since the loss of the control information due to the signal collision in the metal cable communication path 22 can be avoided, the extension control devices 18 and 20 can be accurately controlled.

<Example 5>
FIG. 12 is a diagram illustrating another example of the inter-network communication device 24 of FIG. As shown in FIG. 12, the inter-network communication device 24 of this embodiment is provided with an input / output terminal 106 as means for rewriting a lookup table mounted on the ID selection circuit 48. In other words, the CAN ID, metal cable ID, and priority in the lookup table are changed according to the configuration of the extension control devices 18 and 20. Therefore, in this embodiment, when the look-up table needs to be rewritten, external look-up table update information is input via the input / output terminal 106, and the look-up table is rewritten based on the input update information. As the input / output terminal 106, a non-contact type interface such as optical communication or radio may be applied.

  As described above, the in-vehicle communication system according to the present embodiment has been described with reference to Examples 1 to 5. According to the present embodiment, by installing the extension control devices 18 and 20 on the metal cable communication path 22 different from the existing CAN bus 16, the responsiveness of the control devices 10 and 12 connected to the CAN bus 16 is not impaired. The extension control devices 18 and 20 can be controlled. Further, by providing the inter-network communication device 24 between the CAN bus 16 and the metal cable communication path 22, the extension control devices 18 and 20 can be controlled using the control commands of the control devices 10 and 12, so that the state of the automobile It becomes possible to control according to Furthermore, when adding the extension control devices 18 and 20, the communication software of the ECUs 26 and 30 connected to the CAN bus 16 and the change of the CAN ID can be made unnecessary. Can be avoided. Further, since the inter-network communication device 24 converts the control information on the CAN bus 16 into a digital value and retransmits it, the control information transmitted from the inter-network communication device 24 to the metal cable communication path 22 is the CAN bus. Since the influence of noise generated in the process of crossing 16 is removed, the extension control devices 18 and 20 can be controlled accurately.

  In addition, according to the present embodiment, important information is preferentially transmitted to determine transmission continuation or transmission interruption at the time of collision with other communication signals based on the priority given to the control information. Is possible. Thereby, the responsiveness of a specific control apparatus among the extension control apparatuses 18 and 20 can be improved more. Further, when the control information on the CAN bus 16 is transferred to the metal cable communication path 22, it is possible to reset the metal cable priority different from the CAN bus priority. For example, even if the control information has a low priority on the CAN bus 16, when the control information is transmitted to the metal cable communication path 22, the priority of the control information can be increased. As a result, by reassigning the priority corresponding to the control device whose responsiveness is desired to be improved according to the user's preference among the extension control devices 18 and 20, it is possible to realize control that matches the user's preference.

(Second embodiment)
A second embodiment of an in-vehicle communication system to which the present invention is applied will be described with reference to the drawings. This embodiment differs from the first embodiment in which necessary control information is transferred from the CAN bus 16 to the metal cable communication path 22 in that the necessary control information is transferred from the metal cable communication path 22 to the CAN bus 16. Therefore, the same code | symbol is attached | subjected to the location corresponding to each other, and it demonstrates centering around difference.

  FIG. 13 is a diagram illustrating a configuration of the in-vehicle communication system according to the present embodiment. As shown in FIG. 13, an information panel 111 (hereinafter referred to as an instrument panel 111) and an optical sensor 78 that are communicably connected to the CAN bus 16, and a fog lamp that is communicably connected to the metal cable communication path 22. 80, a fog lamp switch 84, a fog lamp light intensity sensor 112, and the like. The fog lamp light intensity sensor 112 here detects and transmits an abnormality in the light intensity of the fog lamp 80. The fog lamp light intensity sensor 112 is mounted with a fog lamp light intensity sensor ECU, and is connected to the metal cable communication path 22 via the extension transceiver 115. The instrument panel 111 displays a warning according to the detection value of the fog lamp light intensity sensor 112. The instrument panel 111 is mounted with an ECU 26 that receives the detection value of the fog lamp light intensity sensor 112 via the inter-network communication device 110, and is connected to the CAN bus 16 via the CAN transceiver 28. The optical sensor 78, the fog lamp 80, and the fog lamp switch 84 are the same as those in FIG.

  An inter-network communication device 110 is provided between the CAN bus 16 and the metal cable communication path 22. The inter-network communication device 110 selects control information necessary for control of the instrument panel 111 from among the control information passing through the metal cable communication path 22 and transfers the selected control information to the CAN bus 16.

  FIG. 14 is a diagram showing a configuration of the inter-network communication device 110 of FIG. As shown in FIG. 14, the inter-network communication device 110 includes a receiver 116, an ID selection circuit 118, a CAN bit string generation circuit 120, a memory 121, a CAN transmission unit 122, and the like.

  The receiver 116 receives all signals that travel on the metal cable communication path 22. For example, the signal on the metal cable communication path 22 includes control information (metal cable ID: 0012) transmitted from the fog lamp switch ECU 86 and control information (metal) transmitted from the fog lamp light intensity sensor ECU 114 as shown in FIG. Cable ID: 0021). Then, the receiver 116 outputs the metal cable ID included in the reception signal to the ID selection circuit 118 and outputs data other than the metal cable ID included in the reception signal to the CAN bit string generation circuit 120.

  The ID selection circuit 118 has a lookup table. For example, as shown in FIG. 16, the lookup table includes a metal cable ID “0021” assigned to the fog lamp light intensity sensor ECU 114 and a CAN ID for communicating control information of the fog lamp light intensity sensor ECU 114 via the CAN bus 16. “0055” is associated and registered.

  The ID selection circuit 118 collates the metal cable ID output from the receiver 116 with the lookup table. When the metal cable ID to be collated is already registered in the lookup table, the ID for the metal cable is CAN. It is converted into a business ID and output to the CAN bit string generation circuit 120. For example, when the ID selection circuit 118 receives the metal cable ID “0021” from the receiver 116, the ID selection circuit 118 converts the metal cable ID “0021” into the CAN ID “0077” according to the lookup table, and generates a CAN bit string. Output to the circuit 120. On the other hand, when the ID for metal cable to be verified is not registered in the lookup table, the ID selection circuit 118 stops the processing and discards the data. For example, when the ID selection circuit 118 receives the metal cable ID “0012” from the receiver 116, the ID selection circuit 118 stops the processing and discards the data.

  The CAN bit string generation circuit 120 generates a CAN bit string in accordance with the CAN communication protocol based on the CAN ID output from the ID selection circuit 118 and the data output from the receiver 116, and outputs the CAN bit string to the memory 121 or the CAN transmission unit 122. The CAN bit string generation circuit 120 also has a function of calculating an error correction code and adding it to the CAN bit string. Then, the CAN transmission unit 122 transmits the bit string output from the CAN bit string generation circuit 120 or the bit string read from the memory 121 to the CAN bus 16 according to the CAN communication protocol.

  The ECU 26 of the instrument panel 111 receives the control information (CAN ID: 0077) of the fog lamp light intensity sensor 112 transmitted from the inter-network communication device 110. The ECU 26 is preset to receive control information having a CAN ID when the fog lamp light intensity sensor 112 is installed. Then, the ECU 26 decodes the received information and causes the instrument panel 11 to display information such as a warning.

  According to the present embodiment, the inter-network communication device 110 selects only the control information of the fog lamp light intensity sensor 112 necessary for controlling the instrument panel 111 from the control information passing through the metal cable communication path 22 to select the CAN bus 16. Send to. Thereby, even when the fog lamp light intensity sensor 112 is added to the automobile, an increase in the communication amount of the CAN bus 16 is suppressed, so that the responsiveness of the ECUs 26 and 30 connected to the CAN bus 16 can be ensured. In addition, the vehicle-mounted communication system of this embodiment can incorporate 1st embodiment shown in FIGS. 1-12 etc. as needed.

(Third embodiment)
A third embodiment of an in-vehicle communication system to which the present invention is applied will be described with reference to the drawings. This embodiment is different from the first embodiment (for example, FIG. 1) in which the metal cable communication path 22 is applied as the expansion communication path in that a battery line is applied as the expansion communication path. Therefore, the same code | symbol is attached | subjected to the location corresponding to each other, and it demonstrates centering around difference.

  FIG. 17 is a diagram illustrating a configuration of the in-vehicle communication system according to the present embodiment. As shown in FIG. 17, in the in-vehicle communication system of the present embodiment, a battery line 124 is applied as an expansion communication path. The battery line 124 is a wiring for supplying the electric power of the battery 128 mounted on the automobile to the entire vehicle. That is, in the present embodiment, the battery line 124 and the body ground 130 are also used as communication lines.

  The inter-network communication device 24 is connected to the battery line 124 via the coupler 126. The expansion transceivers 40 and 44 are also connected to the battery line 124 via the coupler 126. The coupler 126 is a protection circuit that prevents circuit elements from being destroyed due to a direct current applied to the battery line 124.

  FIG. 18 is a diagram illustrating a configuration in which a coupler 126 is mounted on the inter-network communication device 24. FIG. 19 is a diagram illustrating a configuration of the coupler 126. As shown in FIG. 18, the coupler 126 is disposed between the transmitter 56, the battery line 124, and the body ground 130. In the case of the form shown in FIG. 14, coupler 126 is arranged between receiver 116, battery wire 124, and body ground 130. As shown in FIG. 19, the coupler 126 includes a transformer 132 for insulation, a capacitor 134 interposed between the transformer 132 and the battery line 124, and a transformer 132 and a body ground 130. The capacitor 135 is formed.

  According to the present embodiment, by applying the battery line 124 as the expansion communication path, it is not necessary to newly implement the wiring of the expansion communication path, so the expansion control devices 18 and 20 are retrofitted to the existing automobile. In particular, the present invention can be applied.

  In addition, due to a relatively large amount of noise occurring in the battery line 124, the timing at which the battery line 124 can communicate may be limited. In other words, transmission via the battery line 124 may be temporarily unavailable. In this regard, in this embodiment, a transmission priority is assigned to control information to be transmitted. Therefore, if high-priority information is generated while the transmission of the battery line 124 is delayed, the high-priority information is immediately transmitted at a timing at which communication is possible before other information waiting for transmission. Can be sent. The use of the battery line 124 whose noise level dynamically changes in this way is effective in that important information can be immediately transmitted at a timing when the noise level is low.

  In addition, the vehicle-mounted communication system of this embodiment can include 1st embodiment or 2nd embodiment shown in FIGS. 1-16 etc. as needed.

It is a figure which shows the structure of the vehicle-mounted communication system of 1st embodiment to which this invention is applied. It is a figure which shows the structure of the communication apparatus between networks of FIG. It is a figure which shows the data format of a CAN communication protocol. It is a figure which shows the look-up table mounted in the communication apparatus between networks of FIG. It is a figure which shows the 1st Example of the vehicle-mounted communication system of FIG. It is a figure for demonstrating operation | movement of the fog lamp of FIG. It is a figure which shows the look-up table mounted in the communication apparatus between networks of FIG. It is a figure which shows the 2nd Example of the vehicle-mounted communication system of FIG. It is a figure which shows the 3rd Example of the vehicle-mounted communication system of FIG. It is a figure which shows the lookup table mounted in the communication apparatus between networks of FIG. It is a figure which shows the other example of the communication apparatus between networks of FIG. It is a figure which shows the other example of the communication apparatus between networks of FIG. It is a figure which shows the structure of the vehicle-mounted communication system of 2nd embodiment to which this invention is applied. It is a figure which shows the structure of the communication apparatus between networks of FIG. It is a figure which shows the signal which goes and goes on the metal cable communication path of FIG. It is a figure which shows the lookup table mounted in the communication apparatus between networks of FIG. It is a figure which shows the structure of the vehicle-mounted communication system of 3rd embodiment to which this invention is applied. It is a figure which shows the structure by which the coupler was mounted in the communication apparatus between networks of FIG. It is a figure which shows the structure of the coupler of FIG. 17 or FIG.

Explanation of symbols

10, 12, 14 Control device 16 CAN bus 18, 20 Expansion control device 22 Metal cable communication path 24 Network communication device 48 ID selection circuit 124 Battery line 126 Coupler

Claims (7)

A main communication path to which a control device mounted on the vehicle is connected; an expansion communication path to which the control device is added to the vehicle; and a communication device that relays between the main communication path and the additional communication path. ,
The communication device selects control information having a predetermined identifier corresponding to the control device of the extension communication path from the control information passing through the main communication path, and uses the selected control information as the extension communication An in-vehicle communication system characterized by transferring to a road.   The in-vehicle communication system according to claim 1, wherein the communication device collates priorities given in advance to the control information after selection, and transfers the selection information in descending order of the priorities. The communication device has an identifier conversion table in which an identifier for communication on the main communication path and an identifier for communication on the extension communication path are associated and registered,
The control information having the identifier registered in the identifier conversion table is selected from the control information passing through the main communication path, and the main communication path of the selection information is transferred according to the identifier conversion table when the selection information is transferred. The in-vehicle communication system according to claim 1 or 2, wherein an identifier in the above is converted into an identifier in the additional communication path. The communication device has a priority conversion table in which the priority when communicating on the main communication path and the priority when communicating on the additional communication path are registered in association with each other,
4. The priority of the selection information in the main communication path is converted into the priority of the extension communication path according to the priority conversion table when the selection information is transferred. The in-vehicle communication system according to any one of the above.   The communication device includes a detection circuit that monitors a communication state of the extension communication path and detects that the selection information after the transfer collides with other control information on the extension communication path. The in-vehicle communication system according to claim 1, wherein when the collision is detected, the selection information is re-transferred.   The communication device selects control information having a predetermined identifier corresponding to the control device of the main communication path from among the control information passing through the expansion communication path, and the selected control information is selected from the main communication path. The in-vehicle communication system according to claim 1, wherein the in-vehicle communication system is transferred to the in-vehicle communication system. The in-vehicle communication system according to any one of claims 1 to 6, wherein the additional communication path is a battery line that supplies power to devices mounted on the vehicle.

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