JPH0712005A - Electronic control device for vehicle - Google Patents

Abstract

PURPOSE:To provide an electronic control device for a vehicle constituted such that a corresponding arithmetic program classified by specifications of a control object is selected by reducing a burden to a microcomputer. CONSTITUTION:An electronic control device 11 is constituted by containing a microcomputer 12, external ROM 20 and an address switching command device 21. In the external ROM 20, a different program classified by a plurality of specifications is stored by dividing an address region, and by setting switches SW1, SW2 of the command device 21, corresponding to the specification of an engine mounted on a vehicle, a memory region of the program corresponding to this specification is selected. Accordingly, the electronic control device 11 of setting this external ROM 20 can be used in common relating to the vehicle of different engine specification, and by setting the command device 21, a program corresponding to specification of the vehicle is supplied to the microcomputer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for electronically controlling, for example, a fuel injection amount and an ignition timing of a vehicle engine, the control specifications of which are different depending on the vehicle type. The present invention relates to an electronic control device for a vehicle that can be commonly used for vehicles having different control specifications.

[0002]

2. Description of the Related Art In an engine mounted on a vehicle, it is common to control an engine control amount such as a fuel injection amount and an ignition timing of the engine according to a driving condition of the vehicle by an electronic control unit including a microcomputer. Are known. In this case, along with a control command amount such as an accelerator depression amount, a detection signal of an engine operating state such as a rotational speed or an intake air amount is input to a microcomputer and stored in a ROM or the like set in the microcomputer. The CPU calculates the fuel injection amount and the ignition timing according to the program.

In such an engine that is electronically controlled, a calculation program is set corresponding to each engine specification that differs depending on the type of vehicle to be mounted, the displacement, and the like. Therefore, a plurality of microcomputers each having a different program corresponding to the engine specifications are prepared, a microcomputer having a program suitable for the engine specifications installed in the vehicle is selected, and a control device suitable for each vehicle specification is selected. Are configured.

As a means for solving the problem that it is necessary to prepare a microcomputer having a program different for each engine specification as described above, for example, Japanese Patent Publication 5-1.
In the invention disclosed in Japanese Patent No. 7983, all the correction values corresponding to the different specifications for each engine are stored and set, and one of the correction values is selected from the outside based on the specification switching signal. The correction program is used to correct the calculation program.

In this case, the correction value or the calculation program for each specification is selected by the C which constitutes the microcomputer.
This is done by software inside the PU, and a program is required to select this correction value for each specification.
The program load increases accordingly.

Further, in Japanese Patent Laid-Open No. 3-156153, the arithmetic program itself is divided according to specifications and stored and set in one storage device, and based on signals from sensors mounted on the vehicle, A technique is disclosed in which an arithmetic program that matches the specifications of the controlled object engine is selected. However, in the case of using such means, for example, before executing the calculation routine of the fuel injection amount of the engine,
It is necessary to determine in advance which arithmetic program should be selected. For this reason, at the time of high-speed rotation of the engine in which the interrupt processing of the fuel injection amount calculation routine occurs frequently, the base routine is delayed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and uses a common arithmetic unit without increasing the program load in a microcomputer, and the arithmetic program corresponding to the specifications and vehicle types. It is an object of the present invention to provide an electronic control unit for a vehicle which is rich in economy and versatility and which can be selectively set.

[0008]

An electronic control unit for a vehicle according to the present invention comprises a microcomputer having an arithmetic unit and a storage element, and the microcomputer includes various sensors mounted on the vehicle. Signal is input, and the vehicle-mounted device is controlled according to the calculation result based on these input signals. A large-capacity external storage element is connected to this microcomputer,
Program switching command means for supplying a read address to the external storage element is provided. In the external storage element, a program for each specification of a plurality of control target devices having different specifications is stored for each specification. The program of the specification instructed to be selected is read out and set in the storage element of the microcomputer.

[0009]

In the electronic control unit for a vehicle constructed as described above, the external storage elements connected to the microcomputer are classified according to the specifications of the engine to be controlled. A program is stored, and one of the stored programs for each specification is selected by the program switching command means and stored and set in the storage element of the microcomputer. Therefore, in the microcomputer in which the selected program is set, the control of the electronic fuel injection amount and ignition timing of the engine, which has the specifications corresponding to the program, is executed and can be classified according to the specifications. Instead of a common microcomputer, various specifications of engine control will be executed,
A simplified configuration of the control device is possible.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows, for example, an electronic control unit 11 (ECU) for controlling a fuel injection amount of an engine mounted on a vehicle.
The ECU 11 is provided with a microcomputer 12 for calculating the fuel injection amount and the like. The microcomputer 12 includes a central processing unit 121 (CPU) and a writable RAM 122 that constitutes a storage element that stores a control program and the like.

An analog detection signal from the air flow meter 13 for detecting the intake air amount of the engine to be controlled is input to the microcomputer 12 via the input buffer 14 and converted into digital data by the A / D converter 123. After conversion, it is input to the CPU 121. Digital signals from the throttle switch 15 and the power steering (power steering) switch 16 are input via the input buffer 17 to the input port of the microcomputer 12.
Entered in 124.

CPU 121, RAM 122, A / D converter 12
3, further connected between the input port 124 by the address bus 125 and the data bus 126,
The operation output from the PU121 is transmitted to the output port 127 via these buses 125 and 126, and this output port 127
Outputs a control command to the fuel injection valve 19 of the engine to be controlled via the output buffer 18. Then, for example, the valve opening time of the fuel injection valve 19 is set based on the rectangular-wave-shaped control signal having the set time width, and the calculated fuel injection amount is set.

An external ROM 20 constituting an external storage element is set for such a microcomputer 12. This external ROM 20 has two switches SW1 and SW2.
Is addressed on the basis of a command from the switching command device 21 for generating a 2-bit address signal, and the program data stored in the addressed area is read out, and the input port of the microcomputer 12 is read.
Entered in 124. The input program data is stored in the RAM 122 and used as a control program for the CPU 121.

The external ROM 20 constitutes a characteristic of the electronic control unit 11 for a vehicle, and the external ROM 20 stores a control program which is different for each specification of the vehicle engine to be controlled. Figure 2 shows this external ROM
It shows the storage status of the control program for 20. It stores all specifications of various engines to be deployed in various models. In this embodiment, the external ROM 20 has 128
It has a capacity of K bytes ($ 00000 to $ 1FFFF
), As shown in FIG. 2, arithmetic programs (32 Kbytes each) corresponding to four types of specifications “0” to “3” are stored.

An address is designated from the switching command device 21 to such an external ROM 20. This device 21 has two switches SW1 and S as described above.
Equipped with W2, these switches SW1 and SW2
Each generate a signal of logic "1" when turned on. That is, two switches SW1 and SW2
Bit address data is generated, and an external ROM is used to select one of four types of programs depending on the operation setting state of the switches SW1 and SW2.
A predetermined read address is output to 20. In the command device 21, the states of the switches SW1 and SW2 are set in accordance with the specifications of the engine mounted on the vehicle in a state where the vehicle to which the electronic control device is set is specified.

Explaining the external ROM 20 further, the programs stored in the external ROM 20 are prepared separately, and as shown in FIG. 3A, the program "0" (vehicle "0"), Program "1"
(Vehicle "1"), program "2" (vehicle "2"), and program "3" (vehicle "3") each have a program code of 32K bytes at addresses $ 8000 to $ FFFF. The respective program codes are shown in FIG.
As shown in (B) of, the external RO is simply used as it is.
It is set side by side in M20.

FIG. 4 shows a microcomputer 12 and an external RO.
Shows the connection status with M20, microcomputer
12 outputs the program address to the address bus 125, and the external ROM 20 receives the received address bus.
Based on the signal on 125, the contents (stored data) in the corresponding address are output on the data bus 126. Then, the microcomputer 12 reads the data in the requested address from the data bus 125.

Here, it is assumed that the microcomputer 12 accesses 32 Kbytes of addresses $ 8000 to $ FFFF. In the example shown in FIG.
The addresses A0 to A14 are the addresses A0 of the external ROM 20.
Each of R to A14R is connected. Therefore, no matter which address from $ 8000 to $ FFFF the microcomputer 12 outputs, the external ROM 20 is selected so that the data stored at the corresponding address is output to the microcomputer 12. The output from the A15 of the computer 12 is inverted and the external ROM 20
Is supplied to the / CE (/ indicates inverted logic) terminal. Here, in this external ROM 20, the terminal / CE is at low level "L"
Output data only when. When / CE is at the high level "H", the data output section is in the high impedance state and is in the same state as nothing is connected.

Terminals A16R and A15 of the external ROM 20
R is set to "H" or "L" according to the states of the switches SW1 and SW2 of the switching command device 21, respectively, and the read address is set corresponding to the input of A16R and A15R. FIG. 5 shows the relationship between the states of the switches SW1 and SW2 and the contents of the selected program. The commanding means 21 need not be composed of any switch as long as it can switch the level between "H" and "L".

Next, the operation of the electronic control unit configured as described above will be described. First, the switch SW of the command device 21
It is assumed that 1 is "H", the switch SW2 is set to "L", and the program "2" (vehicle "2") is selected. And the microcomputer 12 has an address of $ 8000
If you access
The signal output from the address bus 215 is $ 8000 as shown in FIG. On the other hand, the signal of the address bus 215 received by the external ROM 20 becomes $ 10000 as shown in FIGS. 3 and 4 and FIG. 6B, and the area of the program "2" is accessed.

Further, if the microcomputer 12 accesses the next address $ 8001, the signal output from the microcomputer 12 on the address bus 215 is
It is $ 8001 as shown in FIG. On the other hand, the signal on the address bus 215 received by the external ROM 20 becomes $ 10001 as shown in FIG. 6D, and the area of the program "2" (vehicle "2") is accessed.

As described above, when the program "2" is selected in the command device 21, when the microcomputer 12 accesses the 32 Kbytes of $ 8000 to $ FFFF, the 32 Kbytes of $ 10000 to $ 17FFF of the external ROM 20 are transferred. Is accessed. Further, when both the switches SW1 and SW2 are set to "H" in the command device 21, when the microcomputer 12 accesses 32 bytes of $ 8000 to $ FFFF, the 32 bytes of $ 18000 to $ 1FFFF of the external ROM 20 are accessed. To be done. In the case of the program "0" and "1", the same access operation is performed.

That is, even if the same address (for example, $ 8000) is accessed in the microcomputer 12,
External R depending on the state of the program switching command device 21
The program area for each vehicle of 00000, $ 00000, $ 08000, $ 10000, $ 18000 will be specified.

Therefore, in the electronic control unit for a vehicle configured as described above, the microcomputer 12 determines and processes switching of programs corresponding to vehicles equipped with engines having different specifications. There is no need, and therefore, no burden is imposed on the microcomputer 12 for managing programs that differ according to specifications. Therefore, even if the number of types of specifications increases, the base routine of the microcomputer 12 is not affected, and the program for each vehicle can be selectively set. For example, even high-speed engine rotation can be controlled reliably. Made possible.

As disclosed in, for example, Japanese Patent Publication No. 5-17983, it is not necessary to set a port for switching judgment to the microcomputer, so that the limited port of the microcomputer can be used. It can be used effectively.

Further, since programs having different specifications for each vehicle are set independently, for example, when it is desired to change the contents of the program "0", only this program "0" is updated. It is only necessary to newly create a program "0 '" and rearrange the program "0'" in place of the program "0" in the contents of the external ROM 20, reducing the load and man-hours on the designer. it can. That is, the external RO as before
It is not necessary to change the entire contents of M.

When only the program "0" is changed, if the external ROM before the change is a and the external ROM after the change is b, the ROMa is the vehicle "1""2".
The ROM before the change can be made valid for "3"
a can be effectively used. When the changed ROMb of the program "0" is completed, the remaining ROMa may be assigned to the electronic control unit for the vehicle "1", the vehicle "2", and the vehicle "3". Then ROM
b may be used.

[0028]

As described above, according to the vehicle electronic control device of the present invention, the external storage element in which a plurality of programs set according to assumed specifications are specified and stored in respective areas is used. By providing an address command to this external storage element from the program switching setting means in which address data is set by a switch or the like, a program for each specification can be created without any burden on the microcomputer. It is selected and supplied to the microcomputer. That is,
Without increasing the program load of the electronic control unit,
The calculation program corresponding to the specifications and vehicle type will be selected and set.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an electronic control device for a vehicle according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a storage area of an external ROM set in the above apparatus.

FIG. 3A is a diagram for explaining individually prepared programs, and FIG. 3B is an external RO in which these programs are stored.
FIG. 6 is a diagram illustrating a storage area of M.

FIG. 4 is a diagram illustrating a connection state between a microcomputer and an external ROM.

FIG. 5 is a diagram showing a relationship between a switch state and selection contents of a program switching command device.

6 (A) and 6 (C) are diagrams showing an example of access from a microcomputer, and FIGS. 6 (B) and 6 (D) are address signals received by an external ROM for the access of (A) and (C). Fig.

[Explanation of Codes] 11 ... Electronic control device, 12 ... Microcomputer, 121 ...
CPU, 122 ... RAM, 123 ... A / D converter, 124 ...
Input port, 125 ... Address bus, 126 ... Data bus,
127 ... Output port, 13 ... Air flow meter, 14, 17 ... Input buffer, 15 ... Throttle switch, 17 ... Power switch, 19 ... Fuel injection valve, 20 ... External ROM, 21 ... Address switching command device.

Claims (1)

[Claims] 1. A microcomputer provided with an arithmetic unit and a storage element, which receives signals from various sensors mounted on a vehicle and controls an on-vehicle device in accordance with an arithmetic result based on these input signals, A large-capacity external storage element coupled to the microcomputer, and a program switching command means for supplying a read address to the external storage element are provided, and the large-capacity external storage element has a plurality of different specifications. Each specification-specific program of the controlled device is stored according to specification, and the program of the specification selected by the switching command means is read out and stored in the storage element of the microcomputer. Electronic control unit for a vehicle.