JPH0466437B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multiplex data transmission system, and particularly to a control system suitable for a wiring system in an automobile.

[Conventional technology]

Automobiles are equipped with electrical components such as various lamps and motors, or electronic devices such as various switches and sensors (hereinafter, the former are referred to as load-type electrical equipment and the latter as signal-generating electrical equipment, and these are simply referred to as electrical equipment). The total number of these items continues to increase with the advent of car electronics, and it is no longer unusual for cars to have hundreds of items.

Therefore, if each electrical component was individually wired, it would cause major problems in terms of space and installation work.To solve this problem, various integrated wiring systems have been proposed. It is starting to be put into practical use.

Therefore, an example of such an integrated wiring system will be explained with reference to FIG. 2.

The system shown in Fig. 2 is, for example,
- This is disclosed in Publication No. 171852, etc., and uses an optical fiber cable OF (hereinafter simply referred to as OF) as a signal transmission path, and uses a central control unit (hereinafter referred to as CCU).
100 and multiple terminal processing devices (Local Control
Unit (hereinafter abbreviated as LCU) 110 to 140 are commonly connected for transmission.
An optical branch connector OC is provided at the branch point of OF.

The CCU is installed near the dashboard of a car and controls the entire system. LCUs are scattered and installed near various electrical components such as switches SW, indicators such as meters μ, lamps L, sensors, etc. that are installed in automobiles. Photoelectric conversion modules 300 to 320 that bidirectionally convert optical signals and electrical signals are provided at the portions where the CCU and LCU are coupled to the OF.

The CCU is equipped with a microcomputer 180 and has a communication function using serial data. CCU, LCU
is LSI dedicated to signal transmission (Communication &
Interface Module. (hereinafter abbreviated as CIM) is provided.

Next, the operation of this system will be explained with reference to FIG.

By the way, the characteristics of the control method in this system are: ● Each LCU controls the CCU CIM in a predetermined order.
and a transmission control program that reads/writes data, ●CCU control data generation in response to switch input, and monitoring functions for each LCU.

In this system, transmission control is performed by periodic timer interrupts, and in Fig. 2, when switch SW1 connected to LCU1 is turned on, the lamp L _o connected to LCU _o is turned on. Suppose that it operates so that it is turned on.
Then, the operation at this time is as follows.

(1) SW1 data is sent to CCU.

(2) The data is taken into the microcomputer by the timer interrupt at time t1.

(3) At time t2, an input change is detected and control data generation is started. During this time, the CCU exchanges data with the CIMs of all LCUs in a predetermined order such as CIM1, CIM2, . . . , CIM _o .

(4) At time _t3 , the process ends.

(5) Control data is loaded into CIM _o by the timer interrupt at time _t4 .

(6) At time t5, _Lo turns on.

That is, the CCU sends and receives data to and from all LCUs, that is, performs monitoring.

[Problem that the invention seeks to solve]

In the above conventional technology, as described above, the CCU exchanges data with all LCUs in a predetermined order. This is extremely inefficient considering the number of switches and loads connected to each LCU. Here, an example of wiring is shown in FIG. The CCU is located near the driver's seat, and LCU1~
It is assumed that constant monitoring is performed with LCU8 and switch changes are detected. However, in an actual vehicle, most of LCU7 and LCU8 near the driver's seat serve as input terminals. In other words, most of the things connected here are signal-generating electrical equipment such as switches and sensors. On the other hand, the other
Most of LCU1, LCU3, LCU4, and LCU6 are output terminals, and some have no input terminals.
In other words, most of the equipment here is load-type electrical equipment such as lamps and actuators.

However, in the conventional method, even under such circumstances, data was exchanged with all LCUs, so even after generating control data, all CCUs
Electrical components cannot be controlled until the LCU data exchange is completed.

In addition, in conventional technology, CCU always uses all LCUs.
There are two reasons why data was being exchanged with:

1 In the future, by adding additional functions to the system
This enabled the connection of additional input devices (switches, sensors, etc.) to the LCU.

2. As mentioned above, CIM exists in CCU and LCU. This CIM does not have a so-called complete fail-safe function, which assumes that a failure has occurred in the signal line when no signal is exchanged between the CCU and LCU for a predetermined period of time, and safely controls the connected load. It was only possible to uniquely cancel/hold the load state. Therefore, even for LCUs that only have output devices connected, it was necessary to constantly monitor and check the data in order to avoid transitioning to the CIM fail-safe state.

If the load inside a car increases further in the future, the number of LCUs will increase correspondingly, and the monitoring cycle will also increase, making it impossible to control electrical components that require high-speed sampling such as vehicle speed sensors, and controlling objects such as lamps and horns. There was a problem in that it was limited to extremely limited electrical components that operated at low speeds.

In view of the above, an object of the present invention is to improve the control method of an integrated wiring system so that high-speed sampling can be realized even when the number of loads in a vehicle increases.

[Means for solving problems]

The integrated wiring system uses three types of data tables for its control: a control table, a monitor table, and a wiring table. Here, the monitor table stores the data that the CCU should send to all LCUs and the data that all LCUs should send back to the CCU, and the wiring table contains wiring information such as which device operates in response to which switch input. In addition to storing data, the control table also stores the order of LCUs (CIMs) that perform control. The system is controlled by detecting changes in the monitor table through monitoring and detecting input. Next, control data based on the input is obtained using a wiring table, and the control data is further transmitted to each LCU using the control table.

Therefore, the purpose of the present invention, ie, high-speed sampling of data, can be achieved by changing the contents of the control table and limiting the LCUs to be monitored to those connected to the input device.

[Effect]

The types and locations of loads in automobiles are significantly uneven, with almost only signal-generating electrical equipment located near the driver's seat, and load-type electrical equipment located near the front and rear parts. This trend is expected to continue. Therefore, even if the total number of in-vehicle devices increases dramatically, the total number of LCUs to which only signal-generating electrical devices are connected will not increase that much, making it possible to maintain sampling speed. In other words, it is also possible to control signal-generating electrical equipment that requires high-speed operation.

In addition, the fail-safe function of the CIM has been improved so that fail-safe data can be supplied to the load as appropriate depending on the driving situation, so the CIM in the LCU that only connects output devices
Even if the device is put into a fail-safe state, the safety of the equipment,
It has no effect on reliability.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. For example, CCU1000 has LCU1, LCU2,
LCU3, LCU4 (1001, 1002, 10 each
03, 1004) are connected, and switch 1005 is connected to LCU1, switch 1006 and lamp 1009 are connected to LCU2, and switch 1007 is connected to LCU3.
1008, and lamp 1010,1 to LCU4
011 is connected. LCU1~
Give 1 to 4 as address # of LCU4,
The CCU shall distinguish.

Before explaining the control method of this system, we will first briefly explain the configuration of the CIM used by the CCU and each LCU.

Figure 5 shows a rough block diagram of an example of CIM, and the electrical components include an input/output buffer 510.
Connected via 0. The CIM operation sequence is such that after receiving data from the receiving terminal RX, the data stored in the shift register 5102 is brought to the input/output buffer 5100 to control the connected loads. On the other hand, input data from a switch or the like is stored in a shift register 5102 via an input/output buffer 5100, and then transmitted from a transmission terminal TX. The failsafe register 5101 stores data for safely controlling the load-type electrical equipment when the signal transmission path between the CCU and the LCU fails. A synchronization circuit 5103 is used to synchronize the clock CK and the received signal.
The transmission control circuit 5104 is used to generate control signals within the CIM. Further, address check circuit 5105 is used to check whether address # is correct or incorrect.

Next, the control table used by this system
An example of TBL _n is shown in FIG. This table is
We are considering 1 byte of data for 1 CIM. Considering loading multiple CIMs in one LCU, the offset # for each CIM is set to 4.
Stored for bit distinction. In this example, one
Since the LCU has only one CIM, it is set to 0.
The remaining 4 bits are the address # of each LCU. As is clear from comparing FIG. 1 and FIG. 6, TBL _n stores only information about the LCUs that are constantly monitored, that is, LCUs 1, 2, and 3 within the dotted line frame in FIG.

Next, an example of the control method of this system is shown in Figure 7.
This will be explained using FIG. In Figure 8,
CCU 801 and 802 become LCU 1,803
It is assumed that LCU3, LCU2 and 804, are connected via a signal line 805. It is assumed that a switch is connected to DIO1 of LCU1, a switch is connected to DIOO of LCU2, and a lamp is connected to DIO1 of LCU3. And in the memory in CCU,
There is the control table (not shown), a monitor table that stores on/off information for all DIO terminals connected to the previous LCU before and after one transmission, and a wiring table that stores the input/output relationships of the terminals in advance. do.

Well, there is a switch for monitoring.
This is done only for LCUs, that is, LCUs 1 and 2.
When the switch connected to DIO0 of LCU2 is turned on, the information before and after transmission in the monitor table differs by one bit. As a result, the CCU learns of changes in input information. If the input information does not change, monitoring continues (see Figure 7).

Next, refer to the wiring table and search for the corresponding output (see FIG. 7). In this example, DIO1 of LCU3
is the output. If you monitor all LCUs only when there is an input change, when monitoring LCU3,
Provides control data about the lamp and turns on the lamp.

According to this embodiment, since monitoring is not performed on LCUs to which no signal-generating electrical equipment is connected, the number of LCUs to be sampled is reduced, and high-speed sampling is possible.

〔Effect of the invention〕

According to the present invention, high-speed sampling can be achieved, so the field of application of this integrated wiring system ranges from electrical components such as lamps and horns, which are sufficient for low-speed operation, to speed sensors, which require a certain level of high-speed sampling. This has the effect of being able to be expanded to include electrical equipment.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figure 2 is a block diagram showing a conventional example of an integrated wiring system, Figure 3 is an explanatory diagram showing the operating sequence of the system, Figure 4 is an explanatory diagram showing an example of wiring inside a car, and Figure 5 is a general diagram of CIM. FIG. 6 is an explanatory diagram showing an example of a control table required for constant monitoring, FIG. 7 is a flowchart showing the control method of this system, and FIG. 8 is an explanatory diagram of the control operation. 100...CCU, 110-140...LCU,
150-170...CIM, 180...Microcomputer, 300-320...Photoelectric conversion module, 1000...CCU, 1001...
LCU1, 1002...LCU2, 1003...
LCU3, 1004...LCU4, 1005~100
8... Switch, 1009-1011... Lamp, 5100... Input/output buffer, 5101...
Fail safe register, 5102...Shift register, 5103...Synchronization circuit, 5104...Transmission control circuit, 5105...Address check circuit, 801...CCU, 802...LCU1, 803
...LCU2, 804...LCU3, 805...Signal line.

Claims (1)

[Scope of Claims] 1. A central control device, a plurality of terminal processing devices each connected to at least one electrical device, and a signal transmission line connecting these central control device and terminal processing devices, In the integrated wiring system, data transmission processing between the central processing unit and the plurality of terminal processing devices is sequentially and periodically executed for each terminal processing device, wherein the data transmission processing is performed by the terminal processing device. Among them, there is a control means that is executed only on the terminal processing device to which the signal generating type electrical equipment is connected, and a change appears in the data from the terminal processing device to which the signal generating type electrical equipment is connected. control means for executing the data transmission process for a terminal processing device to which only load-type electrical equipment among the terminal processing devices is connected. method. 2. A central control device, a plurality of terminal processing devices each connected to at least one electrical device, and a signal transmission path connecting between the central control device and the terminal processing devices, In an integrated wiring system in which data transmission processing between a plurality of terminal processing devices is carried out periodically for each terminal processing device, a signal-generating electrical device among the terminal processing devices is connected. a control table that describes the terminal processing devices that are connected to the terminal processing device, a monitor table that describes data from the terminal processing device to which the signal generation type electrical equipment is connected, and a control table that describes the terminal processing equipment that is connected to the signal generation type electrical equipment; A wiring table is provided that describes the terminal processing devices to which only the terminal processing device is connected, and the control table is used to perform the data transmission processing on the terminal processing device to which the signal generating type electrical equipment is connected. Execute the process to detect a change in data from the terminal processing device to which the signal-generating electrical equipment is connected using the monitor table; 1. A control method for an integrated wiring system, characterized in that the data transmission process is executed for a terminal processing device to which only the load-type electrical equipment is connected. 3 In claim 1 or 2,
Control of an integrated wiring system, characterized in that the signal-generating electrical device is at least one of various switches and various sensors, and the load-type electrical device is at least one of various lamps and various electric devices. method.