JP5296515B2 - Vehicle communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable communication system for vehicles capable of assuring multiplex communication by other communication line even when a communication failure occurs in a part of a communication line of the communication system irrespective of low cost configuration. <P>SOLUTION: The communication system 10 for vehicles is constituted of: a main communication line I; and a sub communication line II which belongs to the main communication line I and whose management level is set as high. A master ECU 1 and a slave ECU_D which belong only to the main communication system I are connected to the sub communication system II so that the multiplex communication is possible using a slave ECU_A which functions as a master ECU in the sub communication line II as a communication relay means. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vehicle communication system, and more particularly to a vehicle communication system that employs a master / slave multiple communication system.

  Conventionally, in a vehicle such as a four-wheeled vehicle, a plurality of ECUs are used to control a smart verification system related to a so-called smart entry (R) function such as engine control and a body system such as an air conditioner, a door, and an airbag control. (Electric control Unit) is installed.

  In such a vehicle communication system, a serial communication function is used, and a master / slave multiple communication system is employed as a communication access method. This multiplex communication system uses so-called LIN (Local Interconnect Network) communication.

  As shown in FIG. 7, in a vehicle communication system 100 employing this type of multiplex communication system, a single master ECU 11 causes four (plural) slave ECUs a, b, c, A device that manages d (hereinafter abbreviated as slaves a to d) is known (see, for example, Patent Document 1).

  In the vehicle communication system 100, a single communication protocol is used, and the master ECU 11, more specifically, a microcomputer (not shown) built in the master ECU 11, the master ECU 11 itself and the slaves a to d. And are managed. Then, multiplex communication is performed between the master ECU 11 and each of the slaves a to d, and the smart verification system and the body system of the vehicle are controlled.

That is, as shown in FIG. 8, the master ECU 11 identifies one of the master ECU 11 and the slave ECUs a to d at each transmission timing scheduled for the master ECU 11 and each of the slaves a to d. A plurality of message frames (message frame sequences) each having a header Hm to Hc including an ID code and an operation command code to be output (serial transmission) via the communication bus LIN (see FIG. 7). Then, the response Rm to Rc including information (data) corresponding to the operation command code is taken into each message frame from either the master ECU 11 or the slaves a to d corresponding to the ID code, and further the same communication It is transmitted to the bus LIN and input to the master ECU 11 and other slaves a to d.
JP-A-9-112338

  However, in such a vehicle communication system 100, the communication bus LIN connecting the master ECU 11 and each of the slaves a to d is fixed at a low level or a high level due to disconnection, ground short, or the like, or If the master ECU 11 becomes inoperable or a communication failure occurs, the entire communication system will not function. In this case, particularly when a communication failure occurs in the smart verification system, it becomes impossible to start and run the vehicle.

  On the other hand, if so-called CAN (Controller Area Network) communication in which each communication bus is composed of a pair of communication lines is adopted, the reliability of communication is improved, but the CAN communication system is expensive, so the cost is reduced. Does not contribute.

  On the other hand, when the communication system for vehicles is composed of two independent communication systems, each communication system performs multiplex communication with LIN communication that is cheaper than CAN communication, and when a communication failure occurs in one communication system However, a configuration for switching to the other communication system is also conceivable, but since two independent communication systems are required, there is still a problem in terms of cost.

  The present invention has been made to solve the above-described problems, and its object is to achieve another communication even when a communication failure occurs in a part of the communication system of the communication system, while having a low-cost configuration. An object of the present invention is to provide a highly reliable vehicle communication system capable of ensuring multiplex communication by a system.

In order to solve the above problems, the invention according to claim 1 is provided for a vehicle, and is configured for a vehicle including a plurality of communication systems each having one or a plurality of slave nodes and a master node as nodes. In the communication system, the plurality of communication systems include a main communication system and a sub communication system connected via a slave node connected to the main communication system, and the slave node is connected to the main communication system. When the system is normal, it functions as a communication relay means for the main communication system and the sub communication system, manages slave nodes belonging to the sub communication system, and is a master node in the sub communication system when a communication failure occurs in the main communication system As a gist.

  According to this configuration, even if a communication failure occurs in the communication bus in the main communication system and multiplex communication via the communication bus becomes impossible, the node functioning as a communication relay means at the normal time without communication failure is By setting the node belonging to the communication system as a master node that manages the node, multiplex communication is ensured in the sub communication system. In addition, since the master node manages one or more nodes belonging to the sub communication system even when there is no communication failure, for example, the master node detects a communication failure in the main communication system, and the sub communication is performed when the communication failure occurs. Since it is not necessary to separately provide an abnormality detection device or the like for switching to the system, the multiplex communication system can be configured at low cost.

The gist of the invention according to claim 2 is that, in the vehicle communication system according to claim 1, a smart verification system ECU belongs to the sub-communication system as a node.
According to this configuration, since the smart verification system ECU belongs to the sub communication system as a node, it is possible to ensure the control function of the smart verification system even when a communication failure occurs in the main communication system other than the sub communication system. Can do.

  The gist of the invention according to claim 3 is that, in the communication system for vehicles according to claim 2, the ECU of the smart verification system includes an ECU for controlling the engine of the vehicle.

  According to this configuration, since the ECU that controls the vehicle engine belongs to the sub communication system as a node, the engine control function is ensured even if a communication failure occurs in the main communication system other than the sub communication system. Can do.

  According to a fourth aspect of the present invention, in the vehicle communication system according to any one of the first to third aspects, the communication relay means is exchanged between a pair of communication buses to which the communication relay means is connected. The gist of the present invention is that it includes a buffer memory for temporarily storing data recorded in the message frame.

  According to this configuration, data recorded in a message frame exchanged between a pair of communication buses is temporarily stored in a buffer memory provided in a master node as a communication relay unit that relays the pair of communication buses. Therefore, even when the block synchronization of the message frame sequence differs between the pair of communication buses, transmission of the message frame sequence is ensured in each communication bus.

  ADVANTAGE OF THE INVENTION According to this invention, although it is a low-cost structure, even when a communication failure arises in a part of communication system of a communication system, the multiplex communication by another communication system is securable.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
As shown in FIG. 1, the vehicle communication system 10 according to the present embodiment is a multiplex communication system configured by two (plural) communication systems of a main communication system I and a sub communication system II. Here, in the main communication system I and the sub communication system II, LIN communication having a common communication protocol is used.

  The main communication system I includes a master ECU 1 as a master node, a slave ECU_D (hereinafter referred to as slave D) as a slave node connected to the master ECU 1 via a communication bus LIN1, and a communication bus LIN1. And the sub-communication system II connected to the master ECU 1 and the slave D.

  The master ECU 1 manages its own master ECU 1 and the slave D by a built-in microcomputer (not shown). The slave D that does not belong to the sub communication system II and belongs only to the main communication system I is of the vehicle body system, and controls the vehicle speed meter based on a vehicle speed signal acquired from a sensor (not shown). At the same time, it functions as an ECU that performs multiplex communication via the communication bus LIN1 and outputs the vehicle speed signal to the master ECU 1.

  The sub-communication system II is a slave ECU_A (hereinafter referred to as slave A) as a slave node, a slave ECU_B (hereinafter referred to as slave B) connected to the slave A via a communication bus LIN2. A slave ECU_C (hereinafter referred to as slave C).

  The sub communication system II is connected to the master ECU 1 and the slave D via the slave A. In other words, the communication bus LIN2 is connected to the communication bus LIN1 using the slave A as a communication relay means (signal transmission exchange means). That is, the message frame sequences transmitted to the communication bus LIN1 and the communication bus LIN2 are exchanged by the slave A.

  Since the slaves A to C belonging to the sub communication system II are all of a smart verification system related to the engine control of the vehicle and have high importance, the sub communication system II is the other in the main communication system I. The management level is set higher than the nodes (master ECU 1 and slave D).

  Specifically, the slave A is an ECU that controls the power source of the vehicle, and a power switch (not shown) provided in the vehicle is operated by the user, whereby the ECU including the slaves B and C, and others It is comprised so that electric power may be supplied to various on-vehicle equipment from a vehicle-mounted power supply.

  In the present embodiment, the slave A also functions as a master node, manages the slave A that is itself by a built-in microcomputer (not shown), and performs multiplex communication via the communication bus LIN2 to B and slave C are managed respectively. Further, the slave A performs multiplex communication via the communication bus LIN1, and also manages the master ECU 1 and the slave D.

  The slave B functions as an ECU for controlling the engine of the vehicle and is connected to a wireless transceiver (not shown), and a portable device (electronic key) possessed by the user of the vehicle via the wireless transceiver. Two-way wireless communication is performed. Then, on the condition that the identification code transmitted from the portable device matches the code stored in its own memory, the door locking / unlocking control device (not shown), its own slave B, or the communication bus LIN1 and / or Multiple communication with the slave A and slave D is performed via the communication bus LIN2, and control of the in-vehicle device by the slave A and slave D is permitted, so that the door of the vehicle can be locked and unlocked and the engine can be started. Or the vehicle meter is operable.

  The slave C functions as an ECU that controls the steering lock device of the vehicle. That is, when the slave B matches the identification code and authentication of the portable device is established, the slave C performs multiplex communication with the slave B via the communication bus LIN2, and releases the steering lock of the vehicle. .

  In the vehicle communication system 10 of the present embodiment, as described above, the master ECU 1 performs multiplex communication via the communication bus LIN1, does not belong to the sub communication system II, and belongs only to the main communication system I. It manages its own master ECU 1 and slave D. In addition, the master ECU 1 performs multiplex communication via the slave A as a communication relay unit and the communication bus LIN2, and also manages the slaves A to C belonging to the sub communication system II.

  In the vehicle communication system 10, as described above, the slave A functions as a master node and manages its own slave A, slave B, and slave C belonging to the sub communication system II. . Further, the slave A belongs to the main communication system I and provides information related to the sub communication system II to the main communication system I.

  That is, as shown in FIGS. 1 and 2, the master ECU 1 schedules the transmission timings of a plurality of message frames for the master ECU 1 and the slaves A to D, which are its own, by means of a built-in microcomputer and a communication bus. Via LIN1, a plurality of message frames (message frame sequences) each composed of a header HM and a response RM, a header HA and a response RA, a header HB and a response RB, a header HC and a response RC, a header HD and a response RD In order, output (serial transmission) at each transmission timing.

  Here, in the headers HM, HA, HB, HC, and HD, the master ECU 1, the ID codes corresponding to the slaves A, B, C, and D, and the master ECU 1 and the slaves A, B, C, and D, respectively. The operation command code at is included. Further, in the responses RM, RA, RB, RC, RD, information (data) output from each node (master ECU 1, slave A, B, C, D) corresponding to the ID code based on the operation command code. ) Is captured.

  Specifically, information (ID code, operation command code) necessary for the headers HM to HC is set by setting the voltage level of the communication bus LIN1 to a low level and a high level by the microcomputer built in the master ECU 1. Captured as a bit string. The microcomputer schedules the transmission timing for each message frame, and each message frame is serially transmitted to the communication bus LIN1 at each transmission timing. The voltage level of the communication bus LIN1 is set to a low level and a high level by the microcomputer built in the master ECU 1 and the microcomputer (not shown) built in the slave D, so that the response RM and the response RD are Information (data) held by the master ECU 1 and the slave D corresponding to each ID code is taken in a bit string.

  On the other hand, the slave A schedules the transmission timing of a plurality of message frames for the slave A, the master ECU 1 and the slaves B to D by the built-in microcomputer, and via the communication bus LIN2. A plurality of message frames (message frame sequence) each composed of a header HM and a response RM, a header HA and a response RA, a header HB and a response RB, a header HC and a response RC, a header HD and a response RD are transmitted in this order. Output at timing (serial transmission).

  Specifically, the information (ID code, operation command code) necessary for the headers HM to HC is a bit string by setting the voltage level of the communication bus LIN2 to low level and high level by the microcomputer built in the slave A. It is captured. The microcomputer schedules the transmission timing for each message frame, and each message frame is serially transmitted to the communication bus LIN2 at each transmission timing. The voltage level of the communication bus LIN2 is set to a low level and a high level by the microcomputer with built-in slave A and the microcomputers with slaves B and C (not shown), so that the response RB, response RC In addition, information (data) held by the slave B and the slave C corresponding to each ID code is taken in as a bit string.

  In the present embodiment, as shown in FIG. 2, since the slave A is configured to start in conjunction with the master ECU 1 after the master ECU 1 is started, the message frame sequence that transmits the communication bus LIN2 is the communication bus LIN2. A delay time Δt [ms] due to the interlocking is generated for the message frame sequence transmitting LIN1. That is, in the communication bus LIN1 and the communication bus LIN2, block synchronization is not achieved for transmission of each message frame sequence, but the bit rate (frequency) is set to be the same.

  In the vehicle communication system 10 according to the present embodiment, as shown in FIG. 2, the slave A functions as a communication relay unit (signal transmission exchange unit), and a predetermined message frame, for example, a header is provided on the communication bus LIN1. When the HM and the response RM (with information about the master ECU 1) arrive, the data recorded in the message frame is temporarily stored in the corresponding buffer memory Bu (hereinafter referred to as buffer Bu).

  Furthermore, when the header HM, which is a message frame corresponding to the message frame, arrives at the communication bus LIN2, the slave A calls the response RM from the built-in buffer Bu and responds. As a result, the data recorded in the message frame consisting of the header HM and the response RM (with information about the master ECU 1) is transferred to the communication bus LIN2, and the message frame is transmitted to the slave B connected to the communication bus LIN2. Used appropriately by slave C.

  On the other hand, as shown in FIG. 2, the slave A functions as a communication relay means (signal transmission exchange means), and a predetermined message frame such as a header HB and a response RB (information on the slave B is present) on the communication bus LIN2. ), The data recorded in the message frame is temporarily stored in the corresponding buffer Bu.

  Further, when the header HB, which is a message frame corresponding to the message frame, arrives on the communication bus LIN1, the slave A calls a response RB corresponding to the message frame from the built-in buffer Bu and responds. As a result, the data recorded in the message frame composed of the header HB and the response RB (with information about the slave B) is transferred to the communication bus LIN1, and the message frame is appropriately used by the master ECU 1 and the slave D. .

  In this embodiment, in this way, multiplex communication is performed between the master ECU 1 and each of the slaves A to D, and the smart verification system and the body system of the vehicle are controlled. That is, in the vehicle communication system 10 according to the present embodiment, the same multiple communication is performed on the basis of the master ECU 1 with the vehicle communication system 100 (see FIGS. 7 and 8) described in the background art. Will be.

  Therefore, according to the vehicle communication system 10 of the present embodiment, as shown in FIGS. 3 and 4, the communication bus LIN1 communicates by fixing the voltage level to low level or high level due to disconnection, ground short, or the like. Even if it becomes impossible, since the communication bus LIN2 and slaves A to C in the sub communication system II operate as they are and multiplex communication is performed, the control of the smart verification system of the vehicle is maintained, the engine of the vehicle is started, and The steering function of the vehicle is ensured as it is. That is, even when the communication bus LIN1 becomes incapable of communication, the vehicle can be started and run.

  According to the vehicle communication system 10 of the present embodiment, as shown in FIGS. 5 and 6, when the slave D fails and becomes inoperable, the header HD and the response RD (slave D about the slave D) are transmitted to the communication bus LIN1. A message frame consisting of no information is transmitted. Then, although a slave response error occurs at the timing shown in FIG. 6 in the microcomputer with built-in slave A, the slave A is relayed and a message in which information about the slave D is not included in the response RD on the communication bus LIN2. Only the frame is transmitted, and there is no adverse effect on the smart verification system of the vehicle.

According to this embodiment, the following operations and effects can be obtained.
(1) In the main communication system I, even if a communication failure occurs in the communication bus LIN1 and the multiplex communication by the communication bus LIN1 becomes impossible, the slave A functioning as a communication relay means when there is no communication failure is By setting the nodes belonging to the sub communication system II (slaves A, B, and C) as master nodes, multiplex communication is ensured in the sub communication system II. Moreover, since the master node manages the nodes (slave A, B, C) belonging to the sub communication system II even when there is no communication failure, for example, the master node detects a communication failure in the main communication system I, and Since it is not necessary to separately provide an abnormality detection device or the like for switching to the sub-communication system II when a communication failure occurs, the multiplex communication system can be configured at low cost.

  (2) Since the smart communication system ECU belongs to the sub-communication system II as a node, even if a communication failure occurs in the main communication system I other than the sub-communication system II, the control function of the smart verification system is ensured. Can do.

  (3) Since the ECU that controls the vehicle engine belongs to the sub communication system II as the slave A, the engine control function is ensured even if a communication failure occurs in the main communication system I other than the sub communication system II. be able to.

  (4) Data recorded in message frames exchanged between the pair of communication buses LIN1 and LIN2 is temporarily stored in a buffer Bu provided in the slave A as a communication relay means for relaying the pair of communication buses LIN1 and LIN2. Therefore, even when the block synchronization of the message frame sequence differs between the pair of communication buses LIN1 and LIN2, transfer of the message frame sequence is ensured in each communication bus LIN1 and LIN2.

The above embodiment may be modified as follows.
In the above embodiment, the sub-communication system II with a high management level includes a smart verification system ECU, that is, slave A that is an ECU that controls the power supply of the vehicle, slave B that is an ECU that controls the engine of the vehicle, and the vehicle The slave D, which is an ECU that controls the steering lock device, belongs as a slave node or a master node. However, the present invention is not limited to this, and the sub-communication system II is an immobilizer that permits the start of the vehicle engine on the condition that the identification code authentication is established in the event of an emergency such as a battery running out of the portable device. It is also possible for an ECU, a vehicle attitude control ECU, or the like to belong as a slave node or a master node.

  In the above embodiment, only the smart verification ECU belongs to the sub communication system II with a high management level, and the body ECU that controls the air conditioner, the door, the airbag, etc. does not belong to the sub communication system II. However, the present invention is not limited to this, and it is of course possible that the body communication ECU belongs to the sub communication system II.

  -In the said embodiment, the radio | wireless communications system which performs the two-way communication with the portable device possessed by the user of the vehicle, and locks and unlocks the door of a vehicle, etc. through authentication establishment of the identification code. Applied to vehicles with. However, the present invention is not limited to this, and the vehicle communication system 10 is a so-called RKE (Remote Keyless) that performs unidirectional communication with a portable device held by a user and locks and unlocks the door of the vehicle after the identification code is authenticated. Of course, the present invention can be applied to a vehicle employing an entry system.

  In the above embodiment, in the sub communication system II, the slave A that functions as a communication relay unit between the communication bus LIN1 and the communication bus LIN2 is configured to function as a master node. That is, it is possible to configure the slave B and the slave C to function as a master node.

  In the above embodiment, the master ECU 1 and the slave A schedule each transmission timing in the order of the header HM and the response RM, the header HA and the response RA, the header HB and the response RB, the header HC and the response RC, the header HD and the response RD. I tried to do it. However, the present invention is not limited to this, and scheduling is appropriately changed in the order of other transmission timings, for example, header HM and response RM, header HD and response RD, header HA and response RA, header HB and response RB, header HC and response RC. It is also possible to do.

The block diagram which shows the electrical constitution of the communication system for vehicles of this embodiment. The time chart which shows the multiplex communication by the communication system for vehicles of this embodiment. The block diagram which shows the state which the communication failure produced in the communication line LIN1 of the communication system for vehicles of this embodiment. The time chart which shows the multiplex communication when the communication failure arises in the communication line LIN1 of the communication system for vehicles of this embodiment. The block diagram which shows the state which the communication failure produced in the slave D of the communication system for vehicles of this embodiment. The time chart which shows the multiplex communication when the communication failure arises in the slave D of the communication system for vehicles of this embodiment. The block diagram which shows the electrical constitution of the communication system for vehicles of a prior art example. The time chart which shows the multiplex communication by the vehicle communication system of a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Master ECU, 10 ... Communication system for vehicles, I ... Main communication system, II ... Sub communication system, A ... Slave ECU (communication relay means), B, C ... Slave ECU, Bu ... Buffer, LIN1, LIN2 ... Communication bus.

Claims (4)

In a vehicle communication system that is provided in a vehicle and includes a plurality of communication systems each having one or a plurality of slave nodes and a master node as nodes,
The plurality of communication systems include a main communication system and a sub communication system connected via a slave node connected to the main communication system,
The slave node functions as a communication relay unit between the main communication system and the sub communication system when the main communication system is normal, and manages slave nodes belonging to the sub communication system, and communication failure of the main communication system occurs. A vehicular communication system that sometimes functions as a master node in the sub-communication system. The vehicle communication system according to claim 1,
A vehicular communication system to which a smart verification system ECU belongs as a node in the sub communication system. The vehicle communication system according to claim 2,
The smart verification system ECU includes an ECU for controlling an engine of the vehicle. In the vehicle communication system according to any one of claims 1 to 3,
The communication relay means includes a buffer memory for temporarily storing data recorded in message frames exchanged between a pair of communication buses connected to the communication relay means.

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