JP3383460B2 - Multiplex transmission equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmission apparatus for controlling, for example, a plurality of communication nodes connected to a common multiplex transmission path to control an electrical unit connected to each node,
In particular, the present invention relates to a multiplex transmission device including a communication node which is supplied with battery power and is connected to a multiplex communication line via a bias circuit.

[0002]

2. Description of the Related Art In recent years, in order to control enlargement and complexity of wiring (wire harness) that connects the electric component units with the increase in the number of electronic parts (electric component units) of automobiles, a plurality of electric component units are controlled. Attention has been paid to the multiplex communication in which the communication nodes provided in the above are connected to a common multiplex communication line, and the signal transmission between the electrical units is performed between the communication nodes.

FIG. 1 shows a circuit configuration of the communication node. As shown, for example, ABS controller (Anti-loc
The communication node that controls the k-brake system) is the communication IC 10
1 is connected to the high speed transmission line MB1 and the medium / low speed transmission line MB2. 100 is a CPU for controlling,
It operates according to a program stored in the RAM / ROM 102. The communication IC 101 controls the physical layer level protocol of the CSMA / CD system. CPU100
Is input with a signal from an input auxiliary device 104 such as various sensors and switches via an input interface (I / F) unit 103, and an output interface (I / F) unit 105.
Output auxiliary device 1 such as a solenoid valve drive motor
A control signal is output to 06.

Further, the CPU 100 is a communication IC 101.
Control signal, the signal input from the input auxiliary device 104 is written in a predetermined communication frame used by another communication node, and is sent to the multiplex transmission path MB1 or MB2.
1 receives the data from the other node as a control signal and sends it to the output auxiliary device 106. That is, CPU1
00 designates the frame data on the bus as the electrical component unit 104
, Or the data from the electrical component unit 104 into a predetermined frame format.

An input signal from the input auxiliary device 104 is sent to the CPU 100 via an input interface (I / F) unit 103.
Is output to. On the other hand, the control signal output from the CPU 100 is the output driver 109 (IPS: inte
It is sent to the output auxiliary device 106 via the lligent power switching. The IPS 109 diagnoses whether the control signal sent from the CPU 100 is normal.

The WD (Watchdog) circuit 107 'is
An abnormal state such as a runaway in the CPU 100 is detected. The WD circuit 107 'prevents the CPU 100 from outputting a normal control signal to the output auxiliary device by detecting an abnormality in the CPU 100, thereby preventing malfunctions or the like in the solenoid valve or the like. The WD circuit 107 'is
When the CPU is normal, a pulse is periodically output from the CPU, and when the pulse is no longer output, the CPU determines that a runaway or some abnormality has occurred, and outputs a reset signal to the CPU.

The CPU 100 and communication IC 10 described above
1, input and output I / F units 103 and 105, WD circuit 1
07 'is an external battery / power source via the power supply circuit unit 108.
Power is supplied from the accessory power supply path + B / ACC or the ignition power IG. Power supply circuit section 10
Reference numeral 8 is connected to each power supply, regulates the drive voltage for the communication node (for example, + 5V), and then supplies power to each circuit inside the communication node.

In the conventional multiplex transmission system, two types of multiplex transmission lines are provided, and communication is possible by turning on an ignition switch (for convenience, referred to as a high-speed transmission line) and a battery power source for continuous communication. (Referred to as a medium-low speed transmission line for convenience). Of the communication nodes connected to these two types of multiplex transmission lines, the communication node connected to the high-speed transmission line is the communication node that controls engine control and ABS control, and the CPU processing speed and memory capacity are large. It is set. on the other hand,
The communication node connected to the medium to low speed transmission line is a communication node that controls the operation of the wiper and various lamps, and the calculation processing speed and memory capacity of the CPU are set to be lower than those of high speed, or in some cases. There is a type that does not have a CPU and transmits and receives a communication frame via a communication IC.

By the way, among the above-mentioned high-speed transmission line and medium-low speed transmission line, particularly in the medium-low speed transmission line, since it is always connected to the battery power source and the line is not disconnected, it is connected to the medium-low speed transmission line. As the number of connected communication nodes increases, the power consumption of the battery increases, and the dark current when not operating because the communication nodes are always on also increases. For this reason, conventionally, as a measure for reducing this dark current, there has been proposed one in which a communication node is provided with a sleep mode for stopping power supply when a predetermined condition is satisfied (see Japanese Patent Laid-Open No. 64-143535). ).

Further, in the conventional multiplex communication system, among communication nodes connected to a medium-low speed transmission line and having a battery power source as a power supply source, especially for a node having a long bus wiring to another node, Bias circuit 11 as shown in FIG.
1 is provided. This bias circuit 111 generates a predetermined potential on the bus when another node transmits a signal on the bus by using predetermined bias resistance values R1 and R2, and Bu
The sI / F (interface) circuit 110 detects this potential and outputs it to the communication IC 101 to establish signal transmission between communication nodes.

As a conventional technique provided with the bias circuit described above, a bias circuit for making the bias resistance value of the bus constant is provided at a specific node through a switch circuit, and the presence or absence of another node is determined. A configuration has been proposed in which a switch circuit is controlled to be opened / closed and the bias circuit is connected to a bus (Japanese Patent Laid-Open No. 5-183559).
issue).

[0012]

However, in the conventional multiplex transmission device as described above, since the dark current increases in proportion to the number of communication nodes using the battery power source as the power supply source, the dark current of each communication node increases. It is not enough to provide the CPU with the sleep mode, and the load on the battery cannot be effectively reduced.

Therefore, the present invention has been proposed in order to solve the above-mentioned problems of the prior art. The object of the present invention is to reduce the number of communication nodes using a battery power source as a power supply source and to reduce the battery power source. We are proposing a multiplex transmission device that can reduce the load.

[0014]

[Means for Solving the Problems] and

In order to solve the above problems and achieve the object, the multiplex transmission apparatus of the present invention has the following configuration. That is, a plurality of communication nodes are connected via a common multiplex transmission line,
In the multiplex transmission device, wherein each of the communication nodes controls an electric equipment unit of a vehicle connected to the communication node, the multiplex transmission device includes a predetermined communication node including at least a bias circuit, and an electric equipment connected to the plurality of communication nodes. Among the units, the electrical equipment units that are operated by being supplied with battery power are collectively connected to the predetermined communication node.

In addition, the vehicle is divided into several parts constituting an automobile, and a plurality of communication nodes are connected to each other through a common multiplex transmission line in units of the parts, and the respective communication is performed. A node is a multiplex transmission device for controlling an electric equipment unit of a vehicle connected to each of the electric equipment units, wherein the multiplex transmission device includes a predetermined communication node including at least a bias circuit, among the electric equipment units connected to the plurality of communication nodes. An electrical equipment unit that is operated by being supplied with battery power is integrated and connected to the predetermined communication node.

[0016] Preferably, the CPU of the predetermined communication node
Has a mode that enters a sleep state when a predetermined condition is satisfied. As described above, by consolidating and connecting the electrical equipment units that operate on the battery power source to the communication node having the bias circuit, it is possible to reduce the number of communication nodes that use the battery power source as a power supply source and to suppress the load on the battery power source. Acts like.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The multiplex transmission device of the embodiment described below is a so-called CSMA (Carrier Sense Multipl
This is an example applied to a vehicle multiplex transmission device of LAN access system called eAccess) / CD (Collision Detection).
Further, in the following description, the embodiment according to the present invention and the related art will be made to correspond to each other, and the description will be made so that the difference in configuration between the two will be clear.

(Arrangement position of all communication nodes and power supply system)
FIG. 3 is a diagram showing the arrangement positions of communication nodes and the power supply system in the entire multiplex transmission system. As shown in FIG.
Cars are roughly classified into Front Sub Assy 1 and Floor Sub
It is divided into 3 sub-assy units (by site): Assy 2 and rear sub-assy 3. In FIG. 3, a front L node 120, a front R node 130 that lights left and right headlamps, and a front R node 130 are provided in a sub-Assy 1 that forms a front area.
MFB (Multi
Function Box) node 300, engine node 310 that controls engine control, ABS controller (Anti-lock-brakes)
An ABS node 320 that manages the ystem) is provided. ASC (Auto-speed-cont
rol) node 140 that controls the system, cowl L node 150 that drives left and right door mirror motors, etc.
A node 160, an air conditioner switch node 170 for controlling the air conditioner, an instrument panel switch node 180 for monitoring the instrument panel switches, a meter node 190 for displaying speedometers and tachometers, a column switch node 200 for monitoring column switches, and switches for the center console. Center console node 2 to monitor
Door FL220, door RL230, door FR240, door R for controlling lock / unlock of 10, 4 doors
R250 is provided. Sub-Assy3 that constitutes the rear area
A rear L node 330 that lights the left and right stop lamps, a rear R node 340, a 4WS (four-wheel steering system) control node 350, and a tail node 260 that lights the tail lamps are provided in the vehicle.

Among the communication nodes shown in FIG. 3, the MFB node 300, the engine node 310, the ABS node 320, the rear L node 330, the rear R node 340, the rear R node 340, and the 4WS control node which branch and output the communication signals from other nodes. 350
Is connected to the high-speed transmission line MB1, the ignition switch is turned on, and power is supplied (hereinafter, the communication nodes connected to these high-speed transmission lines are referred to as high-speed nodes). Communication nodes other than the high speed node shown in FIG. 3 are the front L node 120 and the front R node 13.
0, node 140 that controls the ASC system, cowl L node 150, cowl R node 160, air conditioner switch node 170, instrument panel switch node 180, meter node 190, column switch node 200, center console node 210, door FL 220, door RL 2
30, a door FR240, a door RR250, and a tail node 260, which are connected to the medium / low speed transmission line MB2 and are supplied with battery power, and an accessory switch AC.
There is a device in which C is turned on and power is supplied (hereinafter, communication nodes connected to these medium and low speed transmission lines are referred to as medium and low speed nodes).

<Network Configuration of Communication Node> FIG. 4
FIG. 5 is a diagram showing a network configuration of a communication node for a sub-Assy 1 in the engine room in the front area of the vehicle shown in FIG. 3, and FIG. It is a figure which shows the network structure of the communication node about sub Assy1. In FIG. 4, the front L node 12
0, the front R node 130 is a medium / low speed node connected to the medium / low speed transmission line MB2, and the front L node 12
0 includes a bias circuit 111. This bias circuit 1
About 11 communication nodes each including 11 are provided for each sub-assy in order to keep the voltage level of the bus line constant while the battery power is supplied, and the communication nodes are 4 in total.
Used about individually. The front L node 120 is connected with an output auxiliary device 121 (corresponding to the output auxiliary device 106 shown in FIG. 1) such as a left headlight (high beam / low beam) and a turn signal lamp 121. Similarly, an output auxiliary device 131 such as a right headlight (high beam / low beam) or a turn signal lamp is connected to the front R node 130. These middle and low speed nodes are
Power is always supplied from the battery power, and the power line is not cut even if the ignition switch or accessory switch is turned off. Also, the front L node 12
The front R node 130 and the front R node 130 each have a WD circuit, and prevent troubles such as the headlight not being turned on during nighttime driving due to CPU runaway. In these nodes, when the ignition switch is off, all the doors including the trunk door are closed, and after 30 seconds or more, the sleep mode is entered and the dark current when the CPU is not operating is suppressed as much as possible. There is.

MFB node 300, engine node 31
0, the ABS node 320 is a high-speed node connected to the high-speed transmission line MB1, and each node internally has a CPU for data processing and a WD circuit 107 'for detecting an abnormality of the CPU, like the medium-low speed node. Have. MFB node 300
An ASC actuator 301 and a wiper motor 302 are connected as an output auxiliary device. Similarly, an EGI unit or the like for controlling the engine 311 is connected to the engine node 310. Further, the ABS node 320 has A
Actuator 32 for driving BS control valve etc.
1 is connected. These high speed nodes are powered only when the ignition switch is turned on. Further, the high-speed node also has a WD circuit like the medium-low speed node, and prevents troubles such as ABS due to runaway of the CPU. However, these high speed nodes do not have a sleep mode. This is because the power supply is cut off when the ignition switch is off, so there is no concern about the battery going dead due to excessive dark current, and therefore it is not necessary to provide a sleep mode like in medium-low speed nodes.

(Comparison between Prior Art and Example) Next, referring to FIG.
With reference to FIG. 5 and the multiplex transmission network configuration of FIG. 5, the multiplex transmission network configuration of the embodiment according to the present invention will be described in comparison with the prior art shown in FIG. Note that, in FIG. 5, the parts denoted by the same numbers as those in FIG. 4 have the same functions, and a description thereof will be omitted.

Now, referring to FIG. 5, the front L node 120 and the front R node 13 in the sub Assy 1 shown in FIG.
Focusing on 0, since a battery power source is always connected to these nodes, it is necessary to provide a sleep mode to reduce the dark current. However, since the dark current increases in proportion to the number of communication nodes that use the battery power source as a power supply source, it is not sufficient to provide the sleep mode in the CPU of each communication node to reduce the dark current. It will be even larger if it is equipped with. Therefore, in the present embodiment, the main focus is to reduce the number of communication nodes that use the battery power source as a power supply source as much as possible, and as shown in FIG. 5, the output auxiliary device 1 connected to the front R node 130.
31 is integrated and connected to the front L node 120. With this configuration, it is not necessary to use the front R node 130 as a communication node that supplies battery power, and the power consumed by the WD circuit 107 'and the like can be saved. Further, the vacant front R node 130 can be used as, for example, a high-speed node, and an output auxiliary device 131 ′ that operates by an ignition power source can be newly connected to be used as a communication node having a function different from the conventional one. It may be configured to operate only when the switch is turned on.

One problem with the above configuration is that in FIG. 5, the wire length between the output auxiliary device 131 and the front L node 120 is slightly longer than the conventional one. However, according to the present embodiment, even if the wire length is slightly lengthened, it is not necessary to increase the circuit related to the wire within the sub-Assy, and rather the number of communication nodes using the battery as a power supply source can be reduced. Since it is larger, lower power consumption, system simplification,
The merit such as cost reduction can be prioritized. Furthermore, after subassemblies 1, 2, and 3 are made independent, communication nodes are rearranged based on their functions, and all output auxiliary devices are connected, then multiple transmission lines and power supplies are connected via connectors etc. for each subassy. By connecting with, the assembling property of the entire system can be improved. However, the engine, the ABS, and the 4WS node, which require complicated control, are independently arranged near the control target auxiliary device in order to shorten the wire length.

(Effect of Embodiment) FIG. 6 shows the current consumption of a communication node having a conventional WD circuit and a sleep mode. As in the present embodiment, by connecting the output auxiliary devices that are operated by the battery power source to the communication nodes that incorporate the bias circuit in each sub-assembly, the communication node that uses the battery power source as a power supply source can be connected. In addition to being able to reduce the load, the load on the battery power supply can be suppressed. <Modification> It is obvious that the present invention is not limited to the above embodiment.

For example, the types of communication nodes forming the multiplex transmission network are not limited to those in the above embodiment.

[0027]

As described above, according to the multiplex transmission apparatus of the present invention, the electrical equipment units which are operated by the battery power supply are collectively connected to the communication node which is supplied with the battery power supply and has the built-in bias circuit. As a result, it is possible to reduce the number of communication nodes that use a battery power source as a power supply source, and it is possible to realize simplification of the system of the entire multiplex transmission apparatus and cost reduction.

Further, the communication node containing the bias circuit has a mode in which it sleeps when a predetermined condition is satisfied, so that it is possible to further reduce the dark current. Further, in a multiplex transmission device configured by dividing each of several assemblies constituting an automobile, a battery power supply is supplied to an electrical unit that operates on battery power in units of the assembly, and a bias circuit is incorporated. By consolidating and connecting to the communication node, there is an effect that the automatic assembling property can be improved and the multiple communication lines can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit configuration of a communication node in a conventional multiplex communication system.

FIG. 2 is a diagram showing a circuit configuration of a communication node using a battery power source as a power supply source.

FIG. 3 is a diagram showing a power supply system of a communication node of the entire system.

4 is a diagram showing a network configuration of a communication node for a sub-assy in an engine room of an automobile as a part of the system shown in FIG.

FIG. 5 is a diagram showing a network configuration of a communication node for a sub-assy in an engine room of an automobile according to an embodiment of the present invention.

FIG. 6 is a diagram showing current consumption according to a pulse output from a conventional WD circuit.

[Explanation of symbols]

100 ... CPU 107 '... WD (Watchdog) circuit 111 ... Bias circuit 120 to 260 ... Medium / low speed node 300-350 ... High-speed node MB1 ... High-speed transmission line MB2 ... Medium-low speed transmission line

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-46664 (JP, A) JP-A-2-121436 (JP, A) JP-A-6-178353 (JP, A) JP-A-5- 146080 (JP, A) JP-A-8-26046 (JP, A) JP-B-5-4879 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 9/00 H04L 12 / 40 B60R 16/00

Claims (5)

(57) [Claims] 1. A multiplex transmission apparatus in which a plurality of communication nodes are connected via a common multiplex transmission path, and each of the communication nodes controls an electric component unit of a vehicle connected to the communication node, the multiplex transmission apparatus comprising: A predetermined communication node including at least a bias circuit is included, and among the electric component units connected to the plurality of communication nodes, electric component units that are operated by being supplied with battery power are collectively connected to the predetermined communication node. And multiplex transmission equipment. 2. The vehicle is divided into several assemblies constituting an automobile, and a plurality of communication nodes are connected to each other through a common multiplex transmission line in units of the assembly, and the respective communication is performed. A node is a multiplex transmission device for controlling an electric equipment unit of a vehicle connected to each of the electric equipment units, wherein the multiplex transmission device includes a predetermined communication node including at least a bias circuit, among the electric equipment units connected to the plurality of communication nodes. A multiplex transmission device, characterized in that an electrical unit that is operated by being supplied with a battery power is integrated and connected to the predetermined communication node. 3. The multiplex transmission device according to claim 1 or 2, wherein the CPU of the predetermined communication node has a mode in which a sleep state is set when a predetermined condition is satisfied. 4. The multiplex transmission device according to claim 3, wherein the predetermined condition is satisfied when at least the battery power is supplied to the predetermined communication node. 5. The CP of at least the predetermined communication node is an electrical unit that is operated by being supplied with the battery power.
Auxiliary device that operates based on a control signal from U or the CPU
3. The multiplex transmission device according to claim 1 or 2, which is an auxiliary device that outputs a signal indicating a change in its own state.