JPH0621956A - Multiplex transmission equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] In a multiplex transmission device in which a plurality of control units periodically send and receive signals via a common multiplex transmission line,
It is an object of the present invention to reduce the cost of a multiplex transmission apparatus and to simplify the entire apparatus by reducing the number of timer means required for each control unit in the past. [Structure] First to sixth units are provided via a common multiplex transmission line 2.
In order to configure the multiplex transmission apparatus 1 by connecting the control units 3 to 8 to each other, and to cause at least one of the control units 3 to 8 to transmit a signal from the unit at a preset timing. In addition to providing the timer function, the control unit not having the timer function is configured to control its own operation based on the reception timing of the signal from the control unit having the timer function.

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, and in particular, a plurality of control units are connected to a common multiplex transmission line, and signals are periodically transmitted and received between the control units via the multiplex transmission line. The present invention relates to a multiplex transmission device.

[0002]

2. Description of the Related Art In recent years, various kinds of controls have been digitized along with the rapid progress of electronics technology, and new electric components have been added to increase the demands and added value of users. It tends to be installed.
In this case, a control signal is transmitted using a wire harness in which a large number of electric wires are bundled for each device, but as the electronics become more advanced, the wire harness becomes larger and secures a space for disposing it. And layout tended to be difficult.

Therefore, in order to solve the above-mentioned problems, a vehicle multiplex transmission apparatus applying a multiplex communication technique to an automobile has been developed as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-121436. . This is because a plurality of control units are provided with multiplex communication interfaces for multiplexing and transmitting and receiving data, and these multiplex communication interfaces are provided with one or two twisted pair lines or the like. By connecting to a multiplex transmission line), signals can be exchanged between controllers for control provided in each control unit via a multiplex communication interface. According to this, a large number of signal lines are omitted as compared with the conventional one, the enlargement of the wire harness that bundles these is suppressed, and the wire harness is simplified. A space can be secured and the wire harness can be appropriately laid out.

[0004]

By the way, in a multiplex transmission apparatus in which a plurality of control units are connected by a common multiplex transmission line and signals are transmitted and received between the control units, the signals transmitted from the respective control units are It is required to prevent mutual interference and to efficiently send and receive signals between the control units, and each control unit itself needs to maintain a constant calculation cycle for control. For this reason, conventionally, each control unit is provided with a timer means, and each control unit measures its own transmission timing by this timer means, so that the mutual signals do not interfere with each other. Therefore, each control unit becomes complicated and the cost of the multiplex transmission device increases, and the entire multiplex transmission device becomes large in size. By connecting via the wire harness, the meaning of the multiplex transmission device for suppressing the enlargement of the wire harness and improving the disposition property of the wire harness is diminished.

Therefore, the present invention relates to a multiplex transmission apparatus in which a plurality of control units are connected to a common multiplex transmission line, and signals are periodically transmitted and received between the control units via the multiplex transmission line. It is an object of the present invention to reduce the cost of a multiplex transmission apparatus and to simplify the entire apparatus by reducing the number of timer means required for each control unit.

[0006]

In order to solve the above problems, the present invention is characterized in that it is configured as follows.

First, the invention according to claim 1 of the present application (hereinafter,
The first invention) is a multiplex transmission device in which a plurality of control units are connected to a common multiplex transmission line, and signals are periodically transmitted and received between the control units via the multiplex transmission line. At least one of the control units is provided with timer means for transmitting a signal at a predetermined timing set by the transmission means in the unit, and the timer means is provided in a control unit not provided with the timer means. Is provided with control means for controlling its own operation based on the reception timing of a signal from the control unit provided with.

The invention according to claim 2 of the present application (hereinafter,
In a multiplex transmission device in which a plurality of control units periodically send and receive signals via a multiplex transmission line, as in the first invention, at least two of the plurality of control units are provided. , When a timer means for transmitting a signal at a predetermined timing set in advance by the transmission means in each unit is provided, and one of the control units provided with these timer means and the other control unit goes down the system In addition to the timing changing means for changing the timing so that the signal is transmitted at the transmission timing of the system-down control unit,
It is characterized in that the control unit not provided with the timer means is provided with control means for controlling its own operation based on the reception timing of a signal from the control unit provided with the timer means.

[0009]

According to the first aspect of the invention, the timer means provided in at least one of the plurality of control units causes the transmitting means of the unit to transmit a signal at a predetermined timing and the timer means is provided. In a control unit without a control unit, the control means provided in the unit controls its own operation based on the timing of receiving a signal from the control unit provided with the timer means. Therefore, by providing the timer means to at least one of the plurality of control units connected to each other via the multiplex transmission path, the plurality of control units operate at appropriate timings without interfering with each other. Therefore, it is possible to reliably prevent the situation in which the control units simultaneously perform the transmission operation and the signals collide.
As a result, it becomes unnecessary to provide a dedicated timer for each of the plurality of control units that configure the multiplex transmission apparatus, unlike the prior art, and the cost of the multiplex transmission apparatus can be reduced and the entire apparatus can be It will be configured simply.

In particular, according to the second aspect of the invention, when one of the control units equipped with the timer means is down, the transmission timing of the other control unit equipped with the timer means is the timing provided in that unit. Since the changing unit is configured to change the transmission timing of the control unit that is system down, even if one control unit including the timer unit is down, another control unit is down. Since it functions as a substitute for the control unit, system down of the entire multiplex transmission device is prevented.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

In the present embodiment, the case where the multiplex transmission device according to the present invention is applied to an automobile will be described.

FIG. 1 is an overall schematic configuration diagram of a multiplex transmission apparatus according to the present embodiment. This multiplex transmission apparatus 1 is a multiplex consisting of one or two twisted pair wires or the like configured in a loop. A plurality of control units, for example, the first to sixth six control units 3 to 8 are respectively connected to the transmission path (multiplex communication line) 2, and the multiple signals are transmitted and received between the respective control units 3 to 8. It is a thing.

The first control unit 3 controls the operation of the engine including the control of the fuel injection amount, the fuel injection timing, the intake air amount, etc., and the second control unit 4 The third control unit 5 is a control unit for performing anti-skid control for improving braking performance and traction control for improving steering stability and riding comfort, and the third control unit 5 is a control unit for a four-wheel steering system. Further, the fourth control unit 6 is a control unit for controlling the operation of a lamp system and an alarm device provided on the front right side of the vehicle body, and the fifth control unit 7 is provided on the left front side of the vehicle body. The sixth control unit 8 is a control unit for controlling the operation of the lamp system, and controls the various switches and indicators provided around the steering column.

The first control unit 3 is connected with sensors such as an air flow meter, an engine rotation sensor or a water temperature sensor, and serves as an actuator for controlling the fuel injection amount, the fuel injection timing, the intake air amount and the like. Various electric loads are connected to the second control unit 4
The vehicle is connected to an acceleration sensor for detecting deceleration during vehicle braking, a vehicle height sensor for detecting vehicle height, and the like, and a hydraulic control valve provided in a brake hydraulic circuit for performing anti-skid control, Alternatively, an electric load as various actuators such as a control valve for controlling the supply / discharge of fluid pressure to / from the damper of the suspension device for performing traction control is connected. The third control unit 5 is connected with sensors such as a vehicle speed sensor and an electric load such as a hydraulic control valve that controls the supply and discharge of hydraulic pressure to and from hydraulic cylinders that form the steering mechanism for the front and rear wheels. The fourth control unit 6 includes a front turn signal lamp, a fog lamp, which is provided on the front right side of the vehicle body,
A small lamp and the like are connected, and the fifth control unit 7 is also connected with a front turn signal lamp, a fog lamp, a small lamp and the like provided on the left side of the front part of the vehicle body. Further, the sixth control unit 8 is connected with switches such as a turn right switch, a turn left switch, and a small lamp switch, and various indicators indicating a lighting state of each lamp.

In this embodiment, the first to sixth six control units 3 to 8 are connected to the multiplex transmission line 2, but the number of control units connected to the multiplex transmission line 2 is The number is not limited to six, and in addition to the first to sixth control units 3 to 8, for example, a control unit for controlling meters or various indicators provided on the instrument panel or a rear portion of the vehicle body is provided. A control unit for controlling the lamps, or a control unit for controlling the operation of a door lock / unlock mechanism or a power window drive motor that automatically opens and closes a window provided on the door. It is also possible to connect if necessary.

The first to sixth control units 3 to
The power supply voltage from the battery is directly supplied to the battery 8 or when the accessory switch or the ignition switch is turned on, so that each control unit is activated.

Here, a concrete configuration of each of the control units 3 to 8 will be described with reference to FIG. Although FIG. 2 shows a specific configuration of the first control unit 3, the other control units 4 to 8 also have the first control unit 3 concerned.
The configuration of the first control unit 3 will be described in detail, and the description of the specific configuration of the other control units 4 to 8 will be omitted.

As shown in FIG. 2, the first control unit 3 is connected to the multiplex transmission line 2 via a connector 10, and the other control units 4 to 4 transmitted via the multiplex transmission line 2 are transmitted. The information signal (multiplexed signal) from 8 is received by the reception control unit 11a which is a multiplex interface module, and the signal converted by this reception control unit 11a is input to the controller 12 for logical operation processing, and
The signal output from the controller 12 to the transmission control unit 11b, which is a multiple interface module, is converted and transmitted to the other control units 4 to 8 via the multiplex transmission line 2. Further, various switches and sensors 14 and various electric loads 15 are connected to the controller 12 via an input / output interface 13, and signals from the various switches and sensors 14 are input to the controller 12 and From the controller 12, signals for controlling various electric loads 15 are output.

The first to third control units 3 to 5 perform quick control according to the vehicle speed, the engine speed, etc., and also perform control related to important parts directly involved in the traveling system. Therefore, it is necessary to quickly and accurately send and receive signals between each unit. Therefore, each control unit 3 to 8 controls the transmission timing of the signal transmitted from each unit. Each has a timer function to regulate. Further, in this embodiment, the sixth control unit 8 also has a timer function.

By the way, in the present embodiment, the first
Or, as information signals transmitted from the sixth control units 3 to 8, various kinds of information are transmitted for each frame F having a configuration as shown in FIG. This frame F
Is SOM (start of message) code, priority / destination address code, ID code, VALI
It has a frame structure having a D / INVALID code, a data area, an EOD (end of data) code, an ACK area and an EOM (end of message) code.

The above SOM code is a code indicating the start of the frame F, and each control unit 3 to 8 uses this SO
The start of the frame F is recognized by receiving the M code. Also, of the priority / destination address codes, the priority is a priority order that indicates which signal is to be preferentially processed when the signals collide with each other and are simultaneously transmitted from a plurality of control units 3 to 8. Is shown. On the other hand, the destination address indicates the destination control unit to which the signal should be transmitted. Furthermore, the ID code is a code indicating the content of the data of the frame F, and each of the control units 3 to 8 can know the content of the data area of the frame F by this ID code. In addition, VALID / INVA
The LID code is a code indicating whether data to be transmitted is valid or invalid. In the data area, the number of various data, the content of each data, etc. are shown, and the EOD code is
It is a code indicating the end of data. Further, the ACK area is an area for discriminating whether or not the signals are correctly exchanged between the control units 3 to 8, and the EOM (End of Message) code is a code indicating the end of the frame F. .

The ACK area is composed of a plurality of bits, for example 16 bits, and each control unit 3-8.
Corresponding to the above, a preset bit area is assigned to each unit, and each control unit 3 to 8 confirms normal reception by each bit. That is, the transmission source control unit sets only the bit at the position corresponding to its own unit in the 16-bit ACK area to “0”,
All other bits are set to "1" and one "0" and 15
, "1" bits are transmitted. On the other hand, the control unit on the receiving side checks whether or not the content of the received frame F is error-free, and if there is no error, it is unique to each control unit in the bit area of the position preset for its own unit. The reception confirmation signal (hereinafter, referred to as an ACK signal) is set to "0" and is returned to the transmission source control unit. Therefore, the control unit whose bit area in the ACK area is "0" is
This indicates that the frame F is normally received.

When the ACK signal is not returned from the control unit on the receiving side, it is considered that a reception error has occurred, and the control unit at the transmission source retransmits the frame F repeatedly at a predetermined cycle. If the ACK signal is not returned even if the control signal is transmitted more than the number of times, for example, three times or more, the control unit is removed from the multiplex transmission line 2 as a system down for some reason.

Next, an example of a case in which a signal is transmitted and received between the control units 3 to 8 via the multiplex transmission line 2 and the electric load is controlled in each control unit based on this, a timer function is used. A control operation for controlling the operation of the fourth and fifth control units 6 and 7 having no timer function on the basis of the information signal transmitted from the sixth control unit 8 which has will be described with reference to a flow chart shown in FIG. Then, the controller in the fourth and fifth control units 6 and 7 (the controller similar to the controller 12 of the first control unit 3 shown in FIG. 2) first receives information from one of the control units in step S1. It is determined whether a frame as a signal is received, and if a frame is received (in the case of YES), step S2
It is determined whether or not the frame received in step 6 is a frame indicating steering angle information and the like from the sixth control unit 8 having a timer function. Then, when it is determined that the frame is from the sixth control unit 8, the number of transmissions of the sixth control unit 8 is counted in step S3, and whether the count number has reached a preset predetermined count number in step S4. When it is determined that the predetermined count has been reached, the frame received from the sixth control unit 8 is temporarily stored in the reception buffer of its own reception control unit 11a in step S5. Then, in step S6, the information shown in the frame is loaded into its own controller,
For example, the control operation such as the angle adjustment of the fog lamp is performed according to the steering angle signal, and the count number is reset in step S7 to return.

As a result, as shown in FIG. 5, the fourth and fifth control units 6 and 7 having no timer function are transmitted (ON state) by the sixth control unit 8 having a timer function at a predetermined cycle. The number of times of transmission of the frame F is counted, the own operation is controlled at a predetermined timing based on the count, the frame F from another control unit is taken in, or the own frame F to another control unit is fetched. Transmission (ON state) is performed.

As described above, in the present embodiment, the sixth control unit 8 having the timer function transmits a signal at a predetermined timing, and the fourth and fifth control units 6, 6 having no timer function are provided. In No. 7, the operation of itself is controlled at a predetermined timing based on the number of times of signal transmission from the sixth control unit 8 provided with the timer means. Therefore, it is possible to omit the timer function of at least the fourth and fifth control units 6 and 7 among the plurality of control units 3 to 8 connected to each other via the multiplex transmission path 2, and moreover, the plurality of control units. 3 to 8 operate at appropriate timings that do not interfere with each other, and it is possible to reliably prevent a situation in which the control units 3 to 8 simultaneously perform transmission operations and signal collisions occur. Become. This allows you to
Since it is not necessary to provide a dedicated timer for each of the plurality of control units 3 to 8 constituting the multiplex transmission apparatus 1, the cost of the multiplex transmission apparatus 1 can be reduced, and the entire apparatus 1 can be improved. It can be configured simply.

Next, an example of the control operation when one of the control units having the timer function goes down the system is shown in FIG.
Through the flowchart shown in FIG. 7 to FIG.
In this case, the case where the first control unit 3 is used instead of the sixth control unit 8 as a control unit having a timer function for controlling the operations of the fourth and fifth control units 6 and 7 will be described. To do.

As shown in FIG. 7, the controllers in the fourth and fifth control units 6 and 7, first, step S
In 10, it is determined whether a frame as an information signal from any of the control units is received, and if a frame is received (in the case of YES), the frame received in step S11 has a timer function. 1 It is determined whether the frame is from the control unit 3. When it is determined that the frame is from the first control unit 3, the number of transmissions of the first control unit 3 is counted in step S12, and whether the count number reaches a preset predetermined count number in step S13. If it is determined that the count has reached the predetermined count, the frame received from the first control unit 3 is temporarily stored in the reception buffer of its own reception control unit 11a in step S14. Then, in step S15, the information shown in the frame is taken into its own controller to control the electric load 15 and the like connected to its own control units 6 and 7, and the count number is reset in step S16. And then return.

In step S11, NO
If it is determined that the frame is not the frame from the first control unit 3 having the timer function, it is determined in step S17 whether the frame content indicates data necessary for its own control, If necessary, the following operation is executed from step S14 and the process returns.

When the system of the first control unit 3 goes down for some reason, the control unit having another timer function, for example, the second control unit 4, replaces the first control unit 3 with the first control unit 3. Control unit 3
Instead of this, the operation of the fourth and fifth control units 6 and 7 having no timer function will be controlled.

That is, as shown in FIG. 7, the controller of the second control unit 4 first determines in step S20 whether a frame has been received from any of the control units 3 to 8 and controls any of them. If a frame is received from the unit (YES), step S2
In step S22, it is determined in step S22 whether or not the frame content indicates that the first control unit has gone down the system, and if YES, that is, when the system down of the first control unit 3 is determined. The transmission cycle of its own frame is changed to the transmission timing of the frame of the first control unit 3 which has been system down, and it is shown in step S23 that the first control unit 3 is system down to the other control units 5-8. Send the frame.

As described above, when one of the first to third control units 3 to 5 and the sixth control unit 8 having the timer means is down, another control unit having the timer means, that is, In the present embodiment, the second control unit 4 transmits the signal at the transmission timing of the system-down control unit, so that even if one control unit equipped with the timer means goes down, another control unit Functions as a substitute for the system-down control unit, which prevents the entire system of the multiplex transmission apparatus 1 from going down.

In the present embodiment, the case where the multiplex transmission apparatus according to the present invention is applied to an automobile has been described, but the target to which the multiplex transmission apparatus is applied is not necessarily limited to an automobile.

[0035]

As described above, according to the first aspect of the invention, the operation of the control unit not provided with the timer means is controlled at a predetermined timing based on the transmission timing of the control unit provided with the timer means. It becomes possible to do. Therefore, by providing the timer means to at least one of the plurality of control units connected to each other via the multiplex transmission path, the plurality of control units operate at appropriate timings without interfering with each other. ,
It is possible to reliably prevent a situation in which the control units simultaneously perform the transmission operation and the signals collide. As a result, it becomes unnecessary to provide a dedicated timer for each of the plurality of control units constituting the multiplex transmission apparatus as in the conventional case, and the cost of the multiplex transmission apparatus can be reduced and the entire apparatus can be reduced. Can be configured more simply.

In particular, according to the second aspect of the invention, even if one control unit equipped with the timer means goes down, the other control unit equipped with the timer means functions in place of the system down one control unit. As a result, the system down of the entire multiplex transmission device can be prevented.

[Brief description of drawings]

FIG. 1 is an overall schematic system diagram of a multiplex transmission device.

FIG. 2 is a system diagram showing a specific structure of a control unit that constitutes the multiplex transmission device.

FIG. 3 is an explanatory diagram illustrating an example of a specific configuration of a signal frame.

FIG. 4 is a flowchart showing an example of a control operation of a control unit having no timer function.

FIG. 5 is a time chart diagram showing the transmission timing of a control unit having no timer function.

FIG. 6 is a flowchart showing an example of a control operation of a control unit having no timer function.

FIG. 7 is a flowchart showing a control operation of another control unit when one of the control units having the timer function goes down.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 multiplex transmission apparatus 2 multiplex transmission paths 3-8 1st-6th control unit 11a reception control part 11b transmission control part 12 controller 14 switch, sensor 15 electric load

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Terayama 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (2)

[Claims] 1. A multiplex transmission device in which a plurality of control units are connected to a common multiplex transmission line, and signals are periodically transmitted and received between the control units via the multiplex transmission line,
At least one of the plurality of control units is provided with timer means for transmitting a signal at a predetermined timing set in advance by the transmission means in the unit, and control not provided with the timer means A multiplex transmission device, wherein the unit is provided with control means for controlling its own operation based on the reception timing of a signal from the control unit provided with the timer means. 2. A multiplex transmission device in which a plurality of control units are connected to a common multiplex transmission line, and signals are periodically transmitted and received between the control units via the multiplex transmission line,
At least two of the plurality of control units are provided with timer means for transmitting a signal at a predetermined timing set in advance by the transmission means of each unit, and the control provided with these timer means is provided. One of the units is provided with timing changing means for changing the timing so as to transmit a signal at the transmission timing of the system-down control unit when the other control unit goes down, and the timer means is provided. The multiplex transmission apparatus, wherein the control unit which is not provided is provided with control means for controlling its own operation based on the reception timing of a signal from the control unit provided with the timer means.