JPH06112939A - Multiplex transmitter - Google Patents

Abstract

PURPOSE:To simplify the communication control and to obtain the transmitter with a small size at a low cost by providing a means sending and receiving prescribed format data through plural channels according to the transmission timing to the transmitter. CONSTITUTION:A central ECU 7 is provided on a combination meter 8 of an instrument panel and various data relating to vehicle information are received from a combination switch 10 of a steering handle 9, an input component 11 such as an operation switch or a sensor and a control signal is outputted to various electric components or the like based on the entry. Furthermore, left and right FCUs 5, 6 are interconnected by transmission lines 13 in duplicate made of optical fibers and a center ECU 7 and the left and right FC'Us 5, 6 are similarly connected. Each electronic controller is interconnected by multiplex transmission lines 13-15, a unique transmission timing is generated and a transmission reception means sends/receives data of a single format through plural channels according to the timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmission device for forming multiple communication by forming a network between a plurality of electronic control devices mounted on a vehicle, an aircraft or a ship.

[0002]

2. Description of the Related Art In recent years, for example, in automobiles, the types and number of electrical components mounted on vehicle bodies have been increasing with the progress of electronics. To control such electrical components, a plurality of controllers that control the energization of loads such as lights, motors, or solenoids in accordance with input signals from input components such as operation switches and sensors are used. A plurality of electronic control units (ECU) are configured to be integrated.
In recent years, a plurality of such ECUs are networked to perform multiplex communication to share programs and source data.

Conventionally, as a network system between such ECUs, (1) a bus line system in which a plurality of ECUs are connected in parallel to one cable, (2) each ECU is connected in a bead shape with one cable. , A token ring system in which only the ECU that has acquired the token (transmission right data that means a permit) slot flowing on the network has the transmission right, (3) the entire system is controlled in the ring-connected ECU Loop system having an ECU for controlling, (4)
Further, there is a net-type method in which all the ECUs are connected to each other by a cable, which is disclosed in Japanese Patent Laid-Open No. 64-50156.

In the multiplex communication between the ECUs of such a vehicle, the technique disclosed in the above publication has a heavy load EC.
The processing of U is carried out by utilizing the idle time of the ECU having a light load, so that the load of the ECU is leveled and the program amount of the entire ECU is reduced. Further, the transmission line between the ECUs is duplicated so that even if a transmission line failure such as disconnection of the transmission line occurs, the influence does not spread to the entire system, and communication reliability can be ensured.

[0005]

However, in the above-mentioned conventional example, it is necessary to perform complicated communication control in order to facilitate communication.

That is, according to the above bus line system, the ECU requesting transmission monitors the carrier (data transmission), and when the carrier from another ECU stops, data is transmitted on the line. If the transmitted data collides with other data on the bus, the transmission will fail and will be retransmitted after a suitable time. As described above, it is necessary to detect a collision and prioritize the communication control.

According to the token ring method, it is necessary to acquire the token slot when transmitting. Further, according to the loop method, the ECU that controls the entire system needs to control the transmission timing by time management.

By performing such complicated communication control, the communication control circuit and the communication control program become complicated, which leads to an increase in the number of parts of the device and an increase in the program memory, resulting in an increase in the scale of the device and a cost increase. There was a problem of becoming.

Further, in the multiplex communication system disclosed in the above publication, the load on the ECU is leveled in order to reduce the program amount of the entire ECU. However, unlike the case of general information communication that requires a transmission capacity of several tens of Kbps to several tens of Mbps, if the transmission capacity of several Kbps to several tens of Kbps is sufficient as in the case of electric components of automobiles, the program amount From the viewpoint of reducing the above and eliminating complicated communication control, leveling the load of the ECU is not a very important factor. Therefore, from the viewpoint of eliminating complicated communication control, a sufficient solution has not yet been made.

In view of the above conventional problems, it is an object of the present invention to provide a compact and inexpensive multiplex transmission device by simplifying communication control.

[0011]

In order to achieve the above object, the present invention comprises a plurality of electronic control units forming a network through multiple transmission lines, and between the electronic control units through the multiple transmission lines. In a multiplex transmission device for transmitting and receiving data, the network is formed by a point-to-point combination method, and the format of the data is configured into a single predetermined format, and each of the electronic control devices transmits the data. Transmission timing generation means for generating timing and transmission / reception means for transmitting / receiving the data of the predetermined format on a plurality of channels in accordance with the transmission timing are respectively provided.

[0012]

According to the present invention having the above structure, the electronic control units are connected point-to-point via the multiplex transmission lines, so that the electronic control units are completely connected. The transmission timing generation means of each electronic control device generates its own transmission timing, and the transmission / reception means transmits / receives data of a single format on a plurality of channels according to the transmission timing. As a result, the electronic control units can perform transmission / reception in the same data format without being affected by the transmission / reception timing of each other.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of a vehicle electrical component control system to which a multiplex transmission device according to the present invention is applied.

In the figure, reference numeral 1 denotes an automobile. In this automobile 1, a left ECU 5 is provided in the vicinity of both left and right sides of a dash panel 4 partitioning an engine room 2 and a vehicle compartment 3.
And a right ECU 6 is installed. Further, a central ECU 7 is installed in an instrument panel (not shown) installed on the rear surface side of the dash panel 4.

The central ECU 7 is provided in the combination meter 8 portion of the instrument panel, and from the combination switch 10 provided on the steering handle 9 and the input switch 11 such as an operation switch or a sensor provided on the instrument panel, the vehicle information is transmitted. Various data relating to the above are input, and a control signal is output to various electrical components based on the data. The input parts 11 connected to the central ECU 7 include a hazard switch, fog light switch, rear differential switch, illuminator, auto light sensor, vehicle speed sensor, and the like, and the electrical components connected for control signal output include: There are various warning lights, turn indicators, AT indicators, HI beam indicators and the like.

The electrical components connected to the left ECU 5 for inputting signals include a brake switch, a parking switch, a heated seat switch, a seat belt switch, a door switch, and an exhaust temperature sensor which are turned on when the brake pedal 12 is depressed. , Brake fluid switch, ignition key switch, auto light switch, turn switch / horn switch, wiper / washer switch, lighting switch, etc. The electrical components connected for control signal output include heated seat, keyless LOCK UNLOC
K, wiper Lo / Hi relay, headlight Lo, interior light, ignition key light, curtain light, turn signal light, and combination light.

Further, as electric components connected to the right ECU 6 for signal input, there are a washer level switch, a heated seat switch, an outside air temperature sensor, a door switch, a trunk switch, a shift position switch, a water temperature sensor, etc. Electrical components connected for signal output include heated seats, foot lights, curtain lights, washer motors, fog lights / horns, license lights, tail lights / position lights, backup lights, and combination lights.

The left and right ECUs 5, 6 are connected to each other by a duplicated transmission line 13 made of an optical fiber, and also between the central ECU 7 and the left and right ECUs 5, 6.
They are connected by similar transmission lines 14 and 15, respectively. In this way, each ECU 5, 6, 7 is connected to the transmission line 1
They are connected in a closed loop via 3, 14 and 15, and all data are exchanged between them.

Load drive units 16 and 17 are installed in the front and rear parts on the left side of the vehicle body, and similar load drive units 18, 19 and 20 are installed in the front and rear parts on the right side of the vehicle body and in the center of the rear part of the vehicle body. ing. The load drive units 16 and 17 are connected to the left ECU 5 via the wire harnesses 21 and 22, and the right load drive units 18 and 19 are connected to the right ECU 6 via similar wire harnesses 23 and 24. . On the other hand, the load drive unit 20 in the center of the rear part is connected to the right ECU 6 via a wire harnel 25 branched from a harness 24 on the right rear side.

Further, the ECUs 5, 6, 7 and the load driving units 16, 17, 18, 19, 20 also include a power supply line 27 for supplying electric power from a battery 26 installed in the engine room 2 to each electric component. It is connected.

Each of the load drive units 16 to 20 is a unit having a built-in relay, semiconductor switch, etc., and receives a control signal from the corresponding ECU 5 or 6 to control the energization of electrical components arranged in the vicinity thereof. To do.
That is, the load drive unit 16 on the front left side is
By the control signal from the CU 5, the above-mentioned left head 2
9L, the left side position light 30L, the front left turn signal light 31L, etc. are driven. And the right turn signal light 31R etc. are all driven.

In addition, the rear left and right load drive units 17,
The reference numeral 19 drives the left and right combination lights 32L or 32R including the above-mentioned taillights, brake lights, rear turn signal lights, etc., according to control signals from the left or right ECUs 5, 6. Then, the load drive unit 20 at the center of the rear part is
The backup light 33 and the like provided in the center of the rear portion of the vehicle body described above are driven by the control signal from.

FIG. 2 is a block diagram showing the internal structure of the ECU 5, and the ECUs 6 and 7 have the same structure as that of the ECU 5, and the description thereof will be omitted.

The ECU 5 has an input / output interface / control circuit 51 to which the above-mentioned electric components are connected. The input / output interface / control circuit 51 has an ECU.
5 16-bit MPU 52 for controlling the operation of the whole 5
Are connected. MPU52 is a 2-channel UA
RT (Universal AsychronousR)
receiver and Transmitter), and TX1 and RX1 in the figure are channel channels.
1 UART, TX2, RX2 are channel ch
2 UART. The UART is an LSI transceiver device having a function capable of program-controlling parallel-serial data conversion, insertion of transmission control code, odd-even check code, etc., error detection, and so on.
A light emitting element 5 such as a light emitting diode via the serial communication port built in the U52 and the drive circuit 53.
5 and 56, and light receiving elements 57 and 58 such as photodiodes are connected to RX1 and RX2 via serial communication ports and a receive circuit 54, respectively. The UART 52a, the drive circuit 53, the receive circuit 54, the light emitting elements 55 and 56, and the light receiving element 57,
Reference numeral 58 constitutes a transmission / reception unit that controls the transmission function of the ECU 5.

A fail-safe circuit 59 that controls the fail-safe function of the ECU 5 is connected to a power supply circuit 60 that supplies power to each component of the ECU 5, an input / output interface / control circuit 51, and an MPU 52.

The light emitting element 5 of the ECU 5 having such a configuration
Transmission lines 13a and 14 in which reference numerals 5 and 56 are optical fibers
The light receiving elements of the ECUs 6 and 7 are connected via a through point-to-point (one-to-one). The light emitting elements of the ECUs 6 and 7 are point-to-point coupled to the light receiving elements 57 and 58 of the ECU 5 through the transmission lines 13b and 14b formed of optical fibers. By connecting in this way, the ECU 5,
Since 6 and 7 are fully connected to form an excellent network configuration without waste, and the point-to-point connection method is optimal for adapting the transmission medium of optical communication, the reliability of the transmission lines 13, 14 and 15 is high. Can be easily improved.

Communication between these ECUs 5, 6 and 7 is as follows.
The same data format is used, and the data format is shown in FIGS. 3 (a) and 3 (b).

In the present embodiment, all data is 24 bytes, and the 24 bytes are configured into a single data format for communication. The data amount that can be transmitted in one frame in UART is 1 byte (8 bits). ), So 2
Transmission of 4 bytes requires 24 frames (one packet). In this embodiment, as shown in FIG. 3A, 24 frames are divided into, for example, four blocks A to D, and each block A to D has 6 frames as shown in FIG. 3B. Constitute. Note that FIG. 3 (b)
In the above, the first frame of each of the blocks A to D is an ID frame indicating the type of block, and the last frame of the block is data for error check (checksum or CR).
C code, etc.). The head bit of each frame is a bit that distinguishes the header and the data frame.

Next, the multiplex communication control in the case where such a single data format is used and the data is taken out from the ECU 6 and used by the ECU 6 will be described with reference to FIG. Note that FIG.
FIG. 4 is a timing chart in the multiplex communication of this embodiment.

First, each of the ECUs 5, 6 and 7 performs an initialization process after the system is activated to be in a communicable state. From time t1 thereafter, the transmission source ECU 5 starts transmission of the packet including the above-described four blocks A to D. At time t1, the ECU 5 simultaneously transmits block A (white in the figure) by channels ch1 and ch2. On the other hand, when the ECUs 5, 6 and 7 are system-activated, the reception through the respective channels ch1 and ch2 is also performed. Therefore, the block A transmitted from the ECU 5 is the ECU 6 which has already been system-activated.
7 is received.

The block A received by the ECU 6 is EC
At time t2 when the transmission of U6 starts, the channel ch1,
The signals are simultaneously transmitted to the ECUs 5 and 7 from both ch2 (block A shown by the diagonally right line in the figure). Further, the block A sent from the ECU 5 to the ECU 7 is simultaneously sent to the ECUs 5 and 6 from both of the channels ch1 and ch2 at the time t3 when the transmission of the ECU 7 is started (block A in the left-hand diagonal line in the figure). In this way, each of the ECUs 5, 6 and 7 generates its own transmission timing and transmits the block A according to this transmission timing. As a result, the ECU
The block A transmitted from 5 is ECU5 → ECU6,
ECU5 → Sent to ECU7, and further ECU6 → ECU
7, ECU7 → Sent to ECU6.

As described above, for example, the ECU 5 to the ECU
In the case of transmitting the block A to the ECU 6, a dual system of a route of ECU5 → ECU6 and ECU5 → ECU7 → ECU6 is configured. At that time, for the ECU6, the data from the ECU5 is transmitted to the route of the ECU5 → ECU6 and the ECU7 →
Although it is received by the route of the ECU 6, the route of the ECU 5 → ECU 6 is the shortest route because the source is the ECU 5.

When the data of this main route is valid, the ECU 6 preferentially uses the data of the main route with the shortest route to this source as the main route and other routes as the sub routes, and the main route data is If it is NG, the data of the sub route is used. The NG of this data is the ECU 5, 6, 7 or the transmission line 13, 14, 1.
5 is abnormal, and it is determined when the communication data error continues for a certain time or more, or when the transmission (reception of oneself) of the partner ECU is not performed for the certain time or more.

The ECU 6 having received the block A in this way reads out the necessary data from the corresponding area of the data format and uses it.

From the time t1 when the block A is transmitted, the transmission cycle (communication cycle) of this apparatus is, for example, 5 ms.
When the time t4 when elapses, the ECU 5 that is the transmission source
Updates the corresponding data area of the above data format to block B, and simultaneously transmits this block B by channels ch1 and ch2 as in the case of block A.
As a result, the block B transmitted from the ECU 5 is, like the block A, ECU5 → ECU6, ECU5 →
It is sent to the ECU 7, and further, the ECU 6 → the ECU 7, the ECU 7
→ ECU6 that has been sent to ECU6 and received block B
Reads necessary data from the corresponding area of the data format and uses it.

Further, subsequently, according to the communication cycle,
At times t5 and t6, the remaining blocks C and D are transmitted, respectively, and after the same processing as the blocks A and B, E
The transmission of one packet of data from the CU 5 to the ECU 6 is completed.

The present embodiment has the following advantages.

(1) Each of the ECUs 5, 6 and 7 generates its own transmission timing and transmits each block in accordance with this transmission timing. As a result, each ECU 5,
6 and 7 are not affected by the transmission and reception of other ECUs, and simple communication control is possible even when the ECUs 5, 6 and 7 have different functions from hardware and software. (2) When 24 frames are continuously transmitted when a framing error occurs due to disturbance noise or the like, all the remaining frames are lost.
A frame is divided into blocks A to D, and the transmission cycle (communication cycle) is transmitted, for example, at 5 ms so that a predetermined time interval is provided between the blocks A to D to be transmitted. You can

The present invention is not limited to the illustrated embodiment, and various modifications can be made. For example, each ECU 5,
The communication cycle of 6 and 7 is, for example, 5 ms for the ECU 5,
6 may be set to 10 ms, and the ECU 7 may be set to 20 ms, which are different from each other. Further, the multiplex transmission device of the above-mentioned embodiment has a configuration in which three ECUs are connected by a double transmission line. For example, as shown in FIG. 5, four ECUs are connected by a double transmission line in a net type. You may comprise.

[0041]

As described above, according to the present invention, a plurality of electronic control devices forming a network through multiple transmission lines are provided, and data is transmitted between the electronic control devices through the multiple transmission lines. In a multiplex transmission device for transmission / reception, the network is formed by a point-to-point coupling method, and the format of the data is configured into a single predetermined format, and each electronic control device controls the transmission timing of the data. Since the transmission timing generation means for generating and the transmission / reception means for transmitting / receiving the data of the predetermined format in a plurality of channels according to the transmission timing are respectively provided, communication control is simplified and both hardware and software can be simplified. As a result, it can be realized at a small size and at low cost.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an automobile electrical component control system to which a multiplex transmission device according to the present invention is applied.

FIG. 2 is a block diagram showing an internal configuration of an ECU 5.

FIG. 3 is a diagram showing a data format of the embodiment.

FIG. 4 is a timing chart in the multiplex communication of this embodiment.

FIG. 5 is a diagram showing a modified example of the present embodiment.

[Explanation of symbols]

 13,14,15 Multiplex transmission line 5,6,7 ECU

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomofumi Abe 1-4-1, Chuo, Wako-shi, Saitama Inside Honda R & D Co., Ltd. (72) Inventor Hirohide Suda 1-4-1, Wako-shi, Saitama No. Incorporated in Honda R & D Co., Ltd. (72) Inventor Takayuki Tsuji 1-4-1 Chuo, Wako, Saitama Incorporated in Honda R & D Co., Ltd.

Claims (1)

[Claims] 1. In a multiplex transmission device having a plurality of electronic control devices forming a network via multiplex transmission lines and transmitting and receiving data between the electronic control devices through the multiplex transmission line, The electronic control unit is formed by a two-point coupling method, and the format of the data is formed into a single predetermined format. Each electronic control unit is configured to generate a transmission timing of the data; A multiplex transmission device, each comprising: a transmitting / receiving unit for transmitting / receiving data of a predetermined format on a plurality of channels.