JP2006347258A - Car-mounted adapter for communication and wire harness for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use an ECU commonly irrespective of different protocol etc. and reduce the processing load to an ECU. <P>SOLUTION: The invention includes an adapter 11 to generate trunk connection of electric wires as a wire harness W/H laid in a vehicle to the ECU 12 (electronic control unit), and a communication controlling means 14 performs a protocol transformation of a frame through which the ECU 12 makes transmission and reception via the wire harness W/H as a transmitting path. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle communication adapter and an automotive wire harness, and more particularly to an adapter for relaying and connecting an electric wire of a wire harness routed in an automobile to an electronic control unit (ECU) and a wire harness including the adapter. It is.

  In recent years, automobile manufacturers have been making efforts to reduce the weight of vehicles by reducing the wiring harnesses that are routed to the vehicle body in order to reduce exhaust gas and improve fuel efficiency in response to environmental problems. In addition, it has been proposed to reduce the wire harness routed in the vehicle by constructing a network (vehicle-mounted LAN). For this reason, various electronic control units (ECUs) mounted on the vehicle have appeared that have a communication function that can multiplex and transmit / receive signals corresponding to the vehicle-mounted LAN.

By the way, although ECU which performs various function control is connected to the wire harness routed in the vehicle via a connector (Japanese Patent Laid-Open No. 2003-324824, etc.), in a conventional in-vehicle LAN, a CPU in the ECU It performs all processes such as function control (application functions for controlling sensors, switches, actuators, etc.) and communication control. Therefore, when a version upgrade or the like occurs in the vehicle and the LAN protocol is different, the existing ECU is used because the communication control part is changed even though the original function control part of the ECU is not changed. This causes a problem that the entire ECU must be redesigned. Furthermore, as the communication speed using the wire harness as a transmission path is increased year by year, there is also a problem that processing loads are concentrated on the ECU.
JP 2003-324824 A

  The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to share the ECU and reduce the processing load of the ECU regardless of the difference in the protocol or the like.

In order to solve the above-mentioned problem, the present invention is an adapter that relays and connects an electric wire of a wire harness routed in a vehicle to an ECU (electronic control unit).
There is provided an in-vehicle communication adapter characterized in that the ECU includes communication control means for performing protocol conversion of a frame for transmitting and receiving the wire harness as a transmission path.

With the above configuration, since the protocol conversion function is provided in the adapter, even if the communication protocol of the network to which the ECU is connected differs depending on the vehicle type or the like, the adapter can absorb the difference in the communication method. Therefore, it is possible to share the ECU with an existing one and to suppress an increase in the number of products, and it is possible to reduce the design burden of the ECU.
In addition, the processing load on the ECU can be reduced by moving the protocol conversion function that has been conventionally performed on the ECU side to the adapter side, and the ECU can sufficiently cope with speeding up of the transmission path. . Therefore, it is possible to prevent the processing speed of the ECU from becoming a bottleneck, and it is possible to alleviate the demand for high-speed processing of the ECU.

    Signals are transmitted and received on the transmission path using a plurality of types of protocols, and the communication control means includes a protocol conversion unit that performs protocol conversion of a frame that is transmitted and received by the ECU through the transmission path, and a protocol type when the frame is transmitted. Preferably, a protocol identifier adding unit that adds a protocol identifier that can be identified to the frame and transmits the frame identifier, and a protocol determination unit that determines the protocol identifier when the frame is received.

  With the above-described configuration, the frame flowing through the transmission path is sent with a protocol identifier, so if the receiving side determines the protocol identifier, it can be converted into a protocol that can be recognized by the ECU according to the protocol of the frame. It becomes possible. Therefore, it is possible to send and receive frames by mixing a plurality of protocols on the transmission path, and it is possible to reduce gateway devices that absorb differences in protocols. As a result, transmission delay due to straddling the gateway device can be eliminated.

  The present invention also provides an automobile wire harness characterized in that the above-described in-vehicle communication adapter is connected to an electric wire terminal.

  As is clear from the above description, according to the present invention, the communication control function of the ECU is moved to the adapter, so even if the design change occurs in the transmission path, the adapter can absorb the difference in the communication method and the like. The ECU can be shared with existing ones. Further, by causing the adapter to perform communication control, it is possible to reduce the processing load of the ECU, and it is possible to sufficiently cope with speeding up of the transmission path without causing the ECU to become a bottleneck.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a communication system 10 mounted on an automobile. An adapter 11 (connector) is connected to an electric wire terminal of a wire harness W / H that is arranged in the vehicle and constitutes an in-vehicle LAN. The control unit 12 is fitted and connected to an adapter fitting portion 13 directly attached to the circuit board, and the wire harness W / H is used as a transmission path to transmit and receive frames. The transmission path is a high-speed transmission path such as an optical fiber or a metal cable represented by IEEE 1394, for example.

The adapter 11 incorporates the communication control board 14 connected to the electric wire of the wire harness W / H via the I / O part 17 and exposes the terminal part 18 connected to the communication control board 14 to the adapter front end surface. ing.
The communication control board (communication control means) 14 includes a processing unit 15 that performs various arithmetic controls, and a memory unit 16 that stores data. The processing unit 15 uses a CPU, an ASIC, or the like, and includes a protocol conversion unit 19, a protocol identifier addition unit 20, and a protocol identifier determination unit 21.
The protocol conversion unit 19 allows the ECU 12 to recognize a frame received from the transmission path composed of the wire harness W / H and a function for converting the frame transmitted from the ECU 12 into a protocol matching the transmission path composed of the wire harness W / H. And a function of performing protocol conversion on a frame and transferring it.

As shown in FIG. 3, the protocol identifier adding unit 20 has a function of adding a protocol identifier 29 that can identify the protocol type to the header of the frame 28 that is transmitted from the ECU 12 and output from the protocol conversion unit 19. Yes. In addition to the protocol identifier 29, the frame 28 includes fields such as a destination address, a transmission source address, data, and a CRC.
The protocol identifier determination unit 21 checks the protocol identifier 29 added to the header of the frame received via the wire harness W / H, determines the protocol type of the frame 28, and notifies the protocol conversion unit 19 of the protocol type have.

  The ECU 12 includes an application unit 26 that controls a sensor, a switch, or an actuator, and includes a processing unit 23 that performs various arithmetic controls, and a memory unit 24 that stores data. The adapter fitting unit 13 includes a circuit board of the ECU 12 and The connected terminal portion 25 is exposed.

Next, the communication operation of the adapter 11 will be described.
First, when data (frame) is transmitted from the ECU 12 to another ECU connected via the wire harness W / H, the following operation is performed.
The ECU 12 generates a frame in the application unit 26 of the processing unit 23 and transmits the frame to the communication control board 14 of the adapter 11 via the terminal units 25 and 18. In the processing unit 15, the frame received from the ECU 12 is converted by the protocol conversion unit 19 into a protocol that matches the communication method of the transmission path. Next, the protocol identifier adding unit 20 adds a protocol identifier 29 indicating the type of protocol converted by the protocol converting unit 19 to the header of the frame 28 and sends it from the I / O unit 17 to the wire harness W / H. At this time, for example, a token passing system is used as the LAN communication control system. By rotating the tokens in the order of ID, the adapter 11 receives the token and transmits data when the transmission right is obtained.

Next, when the ECU 12 receives data from another ECU via the wire harness W / H, the following operation is performed.
When the adapter 11 receives the frame 28 from the wire harness W / H, the protocol identifier determination unit 21 checks the protocol identifier 29 in the header of the frame 28, determines the protocol type of the received frame, and notifies the protocol conversion unit 19. Next, the protocol conversion unit 19 converts the frame into a frame that can be recognized by the ECU 12 based on the received protocol type, and transfers the frame to the ECU 12 side via the terminal units 18 and 25.
The ECU 12 performs a predetermined process in the application unit 26 of the processing unit 23 based on the received frame.

According to the above configuration, since the communication control function of the ECU 12 is transferred to the communication control board 14 built in the adapter 11, even if a design change occurs in the transmission path, the adapter 11 absorbs the difference in communication protocol and the like. The ECU 12 does not need to be aware of the network, and the ECU 12 can be shared with existing ones. Further, by providing the adapter 11 with the processing unit 15 to perform communication control, the load on the processing unit 23 of the ECU 12 can be reduced and the necessary resource amount (CPU power, memory capacity, etc.) can be suppressed. Therefore, the speedup performance can be sufficiently exerted as a whole system without the processing speed of the ECU 12 becoming a bottleneck.
Furthermore, since the protocol identifier 29 is attached to the frame 28 and transmitted to the transmission line, if the protocol identifier is determined on the receiving side, it can be converted into a protocol that can be recognized by the ECU 12 according to the protocol of the frame 28. Become. Therefore, it is possible to send and receive frames by mixing a plurality of types of protocols in the transmission path, and the number of gateway devices that relay between different types of existing LANs can be reduced. As a result, transmission delay due to straddling the gateway device can be eliminated.

  When a new function is added to the ECU, it can be dealt with by updating software in the ECU that responds to the ECU. The processing unit 15 of the adapter 11 may employ a CPU, but may be configured with an IC such as a general-purpose logic device (FPGA or PLD).

It is a block diagram which shows the adapter for vehicle-mounted communication of 1st Embodiment of this invention. 1 is an overall view of an in-vehicle communication system. It is drawing which shows a frame format.

Explanation of symbols

10 in-vehicle communication system 11 adapter 12 ECU
13 Adapter fitting part 14 Communication control board (communication control means)
DESCRIPTION OF SYMBOLS 15 Processing part 16 Memory part 19 Protocol conversion part 20 Protocol identifier addition part 21 Protocol identifier discrimination | determination part W / H Wire harness

Claims (3)

An adapter for relaying and connecting an electric wire of a wire harness routed to a vehicle to an ECU (electronic control unit),
An in-vehicle communication adapter, comprising: a communication control unit that performs protocol conversion of a frame in which the ECU transmits and receives the wire harness as a transmission path.   Signals are transmitted and received on the transmission path using a plurality of types of protocols, and the communication control means includes a protocol conversion unit that performs protocol conversion of a frame that is transmitted and received by the ECU through the transmission path, and a protocol type when the frame is transmitted. The in-vehicle communication adapter according to claim 1, further comprising: a protocol identifier adding unit that adds a protocol identifier that can be identified to the frame, and transmits the protocol identifier; and a protocol determination unit that determines the protocol identifier when the frame is received. .   An automotive wire harness, wherein the on-vehicle communication adapter according to claim 1 or 2 is connected to an electric wire terminal.

Images