JP3211708B2 - Vehicle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle control device for controlling a vehicle, and more particularly, to a method for storing a learning value calculated by learning control in an electrically rewritable nonvolatile ROM such as an EEPROM. Vehicle control device.

[0002]

2. Description of the Related Art Conventionally, in a vehicle control device for controlling an engine or an automatic transmission (automatic transmission) of a vehicle, a past control result is evaluated in order to eliminate the influence of the control object with time and individual differences. So-called learning control, in which control parameters and control logic are corrected, is widely adopted. A learning value such as a control parameter calculated by the learning control is stored in a so-called standby RAM (RA which is always supplied with power by a battery voltage).
M, also referred to as a backup RAM).

However, if the learning value is simply stored in the standby RAM, the battery is removed from the vehicle or, if the battery is removed, the learned value calculated so far is lost. Therefore, in recent years, EEPROM
Non-volatile R that can electrically rewrite data
The learning value is written in the OM, and when it is determined that the battery is disconnected, the learning value is transferred from the non-volatile ROM to the normal RAM so that the learning value calculated in the past can be continuously used. I have to.

[0004]

Here, if the frequency of updating and writing the learning value to a non-volatile ROM such as an EEPROM in which data can be rewritten is increased, when the battery is disconnected, it is possible to perform the operation as soon as possible. The learning value can be used for control. However, at present, in this type of non-volatile ROM, the number of guaranteed write operations is set by the semiconductor manufacturer, and data is written beyond the guaranteed number of write operations. Is performed, there is no guarantee that the data is written reliably, so that there is a problem that the learning value cannot be frequently updated and written.

[0005] For example, Japanese Patent Laid-Open No. Hei 5-79379 discloses that the latest learning value is written into the EEPROM at regular intervals, but the period of use of the vehicle (maximum 15 to 20 years) ), The possibility of exceeding the guaranteed number of times of writing is very high. Moreover, this type of vehicle control device is generally supplied with operating power when the ignition switch of the vehicle is turned on, but the vehicle is always driven while the ignition switch is turned on and the device is operating. As a result, there is a possibility that a learning value that is not really useful may be updated and written to the EEPROM, and the number of times of writing data to the EEPROM is unnecessarily increased.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and it is possible to reduce the number of times a learning value is written to an electrically rewritable nonvolatile ROM by a predetermined value without impairing the controllability of learning control. It is an object of the present invention to provide a vehicle control device capable of keeping the number of times within the guaranteed number of times.

[0007]

The vehicle control device according to the present invention includes a nonvolatile ROM in which data can be electrically rewritten, and is calculated by learning control when controlling the vehicle. The learning value is stored in the non-volatile ROM by writing the learning value when the predetermined condition is satisfied. In particular, the driving detection means determines that the vehicle actually operates after the ignition switch of the vehicle is turned on. The counting means counts the number of times that the vehicle has been actually driven by the driving detection means, and the driving number determination means determines that the count value of the counting means has exceeded a predetermined value. Is determined.

The vehicle control device executes the writing of the learning value to the non-volatile ROM when the driving number determination means determines that the count value of the counting means has exceeded a predetermined value. Is initialized.
In such a vehicle control device of the present invention, when the ignition switch is turned on from the off state and the vehicle is actually driven, the count value of the counting means is updated by one. When the count value becomes equal to or more than the predetermined value, the learning value is written into the nonvolatile ROM, and the count value of the counting means is initialized. Therefore, every time the vehicle is driven a predetermined number of times, the latest learning value is written to the nonvolatile ROM.

Therefore, according to the vehicle control device of the present invention,
When the ignition switch is turned on but the vehicle does not drive, the learning value is not written to the nonvolatile ROM, and the truly useful learning value when the vehicle is actually driven is written to the nonvolatile ROM. Can be saved. Then, each time the vehicle is driven a predetermined number of times, the learning value is written to the nonvolatile ROM, so that the number of times of writing data to the nonvolatile ROM can be significantly reduced.

Therefore, the number of times of writing the learning value to the nonvolatile ROM can be suppressed to within a predetermined number of times of guaranteed writing without impairing the controllability of the learning control. By the way, the driving detecting means can be configured to determine that the vehicle has actually been driven, when the engine speed of the vehicle has become equal to or higher than a predetermined speed. With this configuration, it is possible to easily and reliably detect that the vehicle has been driven . Note that the predetermined rotation speed is
It is desirable to set it near the idle speed of the engine.
No.

On the other hand, as described above, this type of vehicle control device is generally configured so that operating power is supplied when an ignition switch of the vehicle is turned on. In this case, a nonvolatile ROM is used. If the vehicle driver turns off the ignition switch while performing the process of writing the learning value to the storage device, the writing process may be interrupted and the learning value to be stored may be destroyed.

Therefore, in order to solve this problem, a running state detecting means for detecting whether the vehicle is running at a predetermined speed or more is additionally provided, and the count value of the counting means is determined by the driving frequency determining means. Is determined to be equal to or greater than a predetermined value,
When the traveling state detecting means detects that the vehicle is traveling at a predetermined speed or higher, the nonvolatile ROM
It is sufficient to write the learning value into the memory and initialize the count value of the counting means.

That is, even if the count value of the counting means is determined to be equal to or greater than the predetermined value by the driving frequency determination means, the nonvolatile ROM is provided if the vehicle is not running at a predetermined speed or more.
The learning value is not written into the learning value, but the learning value is written when the vehicle is running at a predetermined speed or higher.

With this configuration, the learning value can be written to the non-volatile ROM in a situation where there is no possibility that the ignition switch is turned off by the vehicle driver, and the learning value to be stored is destroyed. This can be reliably avoided.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. It is needless to say that the embodiments of the present invention are not limited to the following, and can take various forms as long as they belong to the technical scope of the present invention.

FIG. 1 is a block diagram showing the configuration of a vehicle engine control device (hereinafter, referred to as an ECU) 1 according to an embodiment. As shown in FIG. 1, the ECU of the present embodiment
Reference numeral 1 denotes a CPU 3 for executing various processes for controlling an engine mounted on a vehicle, a ROM 5 for storing a program executed by the CPU 3, and a normal operation for temporarily storing control operation results and the like by the CPU 3. RAM
(That is, a RAM that is not backed up by a power supply using a battery voltage, and is hereinafter referred to as an N-RAM).
A standby RAM (hereinafter referred to as S-RAM) 9 which is backed up by a power supply using a battery voltage; and an EEPROM 11 as a nonvolatile ROM in which data can be electrically rewritten.

The CPU 3, the ROM 5, and the N.RAM
7, and the SRAM 9 are connected to each other by a bus 13, and the CPU 3 and the EEPROM 11 are connected by a serial data line 15. Still further, the ECU 1
An input circuit 21 for inputting signals from various sensors such as a speed sensor 17 for detecting the engine speed NE of the engine and a vehicle speed sensor 19 for detecting the traveling speed (vehicle speed) v of the vehicle to the CPU 3, and an output from the CPU 3 An output circuit 25 for operating an actuator 23 such as an injector or an igniter in accordance with the drive signal to be supplied;
From the CPU 3, the ROM 5, the ignition voltage VIG supplied from the
The operating voltage VD is output to the N-RAM 7, the S-RAM 9, and the EEPROM 11, and the battery voltage V BB directly supplied from the battery 27 without passing through the ignition switch 29 is received. And a power supply circuit 31 for outputting VS.

In such an ECU 1, when the ignition switch 29 is turned on (turned on), the operating voltage VD is supplied from the power supply circuit 31 to the CPU 3, the ROM 5, the N.RAM 7, and the like. Then, the CPU 3 sets the RO
The engine is controlled by executing an engine control process according to a program stored in M5 and operating the actuator 23 based on sensor signals from various sensors.

The engine control process executed by the CPU 3 is based on learning control. And CPU3
Is a learning value such as a control parameter calculated on the N-RAM 7 by the learning control, and a N-RAM 7
The value of the counter C counted up above is
Copy it to M9 regularly and use ignition switch 2
The learning value and the value of the counter C are not lost even during the turning off of the switch 9. When a condition described later is satisfied, the CPU 3 stores the learning value in the N-RAM 7 in the EEPROM 11.
To the battery 27.
Even if the stored data in the S-RAM 9 is lost due to the error.

Then, the CPU 1 is executed by the ECU 1 as described above.
3 will be described with reference to the flowchart of FIG. In the process shown in FIG. 2, the operation and determination of the counter C and a flag F described later are determined by N · RA
It is performed on M7. As shown in FIG. 2, when the CPU 3 starts operating in response to the turning on of the ignition switch 29, first, steps (hereinafter, referred to as S) 100 to S 1 are performed.
The initialization processing of 30 is performed.

That is, first, in S100, it is determined whether or not there is a history of battery disconnection (that is, a trace of the battery 27 being disconnected). This determination is made, for example, by checking the stored data in the S-RAM 9. If the stored data is normal, it is determined that there is no history of battery disconnection. Conversely, if the stored data is abnormal, there is a history of battery disconnection. Is determined.

If there is no history of battery disconnection, the process proceeds to S110, where the data stored in the S.RAM 9 (that is, the S.R.
The learning value and the value of the counter C which have been backed up in the RAM 9 are written in the N-RAM 7. If there is a history of battery loss, the data stored in the S-RAM 9 is indefinite, so the process proceeds to S120 and the learning value written in the EEPROM 11 at that time is
Write to N · RAM7.

After performing one of the processes in S110 and S120, the process proceeds to S130, in which a flag F indicating whether the vehicle is actually driven after the ignition switch 29 is turned on is set to a flag F. Set to "0" indicating that it has not been operated yet.

After completing the initialization processing of S100 to S130, the CPU 3 starts the execution of the engine control processing by the learning control and periodically executes the processing of S140 to S230 in parallel with the engine control processing. Execute repeatedly. That is, first in S140, the N.RAM7
The learning value and the value of the counter C currently stored in
Write (copy) to the RAM 9

Then, in subsequent S150, it is determined whether or not the flag F is "0".
The engine speed NE detected on the basis of the signal from the speed sensor 17 is changed to a predetermined speed (in the present embodiment, a value near the idle speed 5 in the present embodiment).
00 rpm) is determined.

If the engine speed is 500 rpm or more, it is determined that the vehicle has actually been operated after the ignition switch 29 is turned on, and the program proceeds to S170, where the value of the counter C is set to N.・ RAM7
The above is incremented by one, and then at S180, "1" indicating that the vehicle has been driven is set to the flag F.

Then, the flag F is set to "1" in S180, or the flag F is set in S150.
Is not "0", or when it is determined in S160 that the engine speed NE is not more than 500 rpm, the process proceeds to S190, and the value of the counter C is set to a predetermined value ( In the present embodiment, it is determined whether or not 10) or more. If the value of the counter C is 10 or more, the process proceeds to S200, and the vehicle speed v detected based on the signal from the vehicle speed sensor 19 is equal to or higher than a predetermined speed (40 km / h in the present embodiment). It is determined whether or not there is.

Here, if the vehicle speed v is 40 km / h or more,
In S210, the learning value currently stored in the N-RAM 7 is updated and written in the EEPROM 11, and in S220, the value of the counter C is initialized to "0". Then, the counter C is initialized in S220, or the value of the counter C is determined not to be 10 or more in S190, or the vehicle speed v is determined in S200.
Is not equal to or higher than 40 km / h, another subsequent process is executed, and during that time, as shown in S230, N
The learning value on the RAM 7 is updated by learning control. Then, the process returns to S140, and the latest learning value currently stored in the N-RAM 7 and the value of the counter C are replaced by S ·
The data is written into the RAM 9, and the above-described processing from S150 is repeated.

In the ECU 1 of this embodiment, after the ignition switch 29 is turned on and the operation is started, a negative determination is made in S160 until the engine speed NE becomes 500 rpm or more, and the engine speed NE is maintained.
Is 500 rpm or more, it is determined that the vehicle has actually been driven, and the value of the counter C is set to 1 by the processing of S170.
Incremented.

When the value of the counter C is incremented by one, the flag F is set to "1" by the processing of S180.
While No. 9 is in the ON state, a negative determination is made in S150,
The value of the counter C is no longer incremented.
Further, the value of the counter C is determined by S · R
Stored in the AM 9 and then the ignition switch 29
Is inserted, N · RAM
7 is written.

For this reason, the value of the counter C is determined by the engine speed NE after the ignition switch 29 is turned on.
Every time a condition occurs where
It will be counted up by one. If the value of the counter C becomes 10 or more and the vehicle speed v becomes 40 km / h or more, the affirmative determination is made in both S190 and S200, and the learning value in the N-RAM 7 is stored in the EEPROM 11 by the processing in S210. Is updated and written in
, The value of the counter C is initialized to "0".

Therefore, in the ECU 1 of the present embodiment, every time the state where the engine speed NE becomes 500 rpm or more after the ignition switch 29 is turned on occurs 10 times, that is, the vehicle is actually operated 10 times. Every,
The writing of the learning value to the EEPROM 11 is executed.

Therefore, according to the ECU 1 of the present embodiment,
When the ignition switch 29 is turned on but the vehicle is not driven, the learning value is not written in the EEPROM 11, and a truly useful learning value when the vehicle is actually driven is written and stored in the EEPROM 11. be able to. Then, the learning value is written to the EEPROM 11 every time the vehicle is driven ten times, so that the number of times of writing data to the EEPROM 11 can be greatly reduced.

Therefore, according to the ECU 1, the number of times of writing the learning value to the EEPROM 11 during the use period of the vehicle can be suppressed to within the predetermined number of times of guaranteed writing without impairing the controllability of the learning control. . Also,
Since the fact that the vehicle has actually been driven is determined based on the fact that the engine speed NE has become equal to or higher than the predetermined speed, it is possible to easily and reliably detect that the vehicle has been driven.

Depending on the timing at which the battery is disconnected, only the learning value of the worst nine cycles before may be stored in the EEPROM 11 and the latest learning value may not be reflected in the control. It is usually impossible to remove 27, and if learning control is performed several times, the learning value even a few cycles ago does not extremely deviate from the optimal value due to the nature of the learning control. Has little effect on gender.

On the other hand, in the ECU 1 of this embodiment, even if the value of the counter C becomes 10 or more, the vehicle speed v becomes 40 km / h.
Otherwise, the learning value is not written to the EEPROM 11, and if the vehicle speed v is 40 km / h or more, the EEPROM
The learning value is written to M11. For this reason,
The learning value can be reliably written to the EEPROM 11.

That is, if the vehicle driver turns off the ignition switch 29 during the process of writing the learning value to the EEPROM 11, the writing process is interrupted and the learning value in the EEPROM 11 is destroyed. . Therefore, if the battery is disconnected immediately after that, the past learning value cannot be used, but if the vehicle speed v is 40 km / h or more, the ignition switch 29 may be turned off. No sex, E
This makes it possible to reliably write the learning value to the EPROM 11, and the problem that the learning value is destroyed does not occur.

In this embodiment, S130, S15
The processing of 0, S160, and S180 corresponds to driving detection means, the processing of S170 corresponds to counting means, the processing of S190 corresponds to driving number determination means, and the processing of S200 corresponds to running state detection means. I have.

The rotation speed determined in S160 in FIG. 2 is not limited to "500 rpm", but can be set as appropriate. However, it is desirable to set the rotation speed near the idle speed of the engine as in this embodiment. . Also, the number of times determined in S190 of FIG. 2 is not limited to “10 times”, and may be appropriately set based on the total number of times of operation expected during the use period of the vehicle and the guaranteed number of times of writing in the EEPROM 11. Can be. That is, the number of times of writing the learning value to the EEPROM 11 during the use period of the vehicle may be set so as not to exceed the above-mentioned guaranteed number of times of writing.

Similarly, the vehicle speed (40 km / h) determined in S200 of FIG. 2 can be appropriately set. On the other hand, in the above embodiment, the EEPROM is used as the data rewritable nonvolatile ROM, but a flash ROM may be used.

In step S210 in FIG. 2, the value of the counter C may be written into the EEPROM 11 together with the learned value. In this way, if there is a history of battery loss, the value of the counter C in the EEPROM 11 is transferred to the N-RAM 7 in S120 of FIG. The value of the counter C can be used continuously.

Further, the ECU 1 of the above embodiment controls the engine of the vehicle, but other vehicle control devices such as an electronic control device for controlling an automatic transmission may be configured in exactly the same manner. Can be.

[Brief description of the drawings]

FIG. 1 is a vehicle engine control device (EC) according to an embodiment;
It is a block diagram showing the structure of U).

FIG. 2 is a flowchart illustrating a process executed by an ECU of FIG. 1;

[Explanation of symbols]

1. ECU (vehicle engine control device) 3. CPU
5 ROM 7 N RAM (normal RAM for calculation work) 9 S RAM (standby RAM) 11 EEP
ROM 17 ... Rotation speed sensor 19 ... Vehicle speed sensor 21 ... Input circuit 23 ... Actuator 25 ... Output circuit 27 ... Battery 29 ... Ignition switch 31 ... Power supply circuit

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hirokazu Oguro 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. 56) References JP-A-5-79379 (JP, A) JP-A-8-15397 (JP, A) JP-A-62-132256 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , (DB name) F02D 45/00 340 F02D 45/00 376

Claims (4)

(57) [Claims] 1. A nonvolatile ROM having electrically rewritable data, and a learning value calculated by learning control when controlling a vehicle is written in the nonvolatile ROM when a predetermined condition is satisfied. In the vehicle control device configured to store the learning value, a driving detection unit that detects whether the vehicle is actually driven after an ignition switch of the vehicle is turned on, and the driving detection unit Counting means for counting the number of times that the vehicle has been actually driven, and driving number judgment means for judging whether or not the count value of the counting means has exceeded a predetermined value. Means determines that the count value of the counting means is equal to or greater than a predetermined value.
A vehicle control device configured to execute writing of a learning value to the OM and to initialize a count value of the counting means. 2. The vehicle control device according to claim 1, wherein the driving detection unit determines that the vehicle is actually driven by determining that the engine speed of the vehicle is equal to or higher than a predetermined speed. A vehicle control device. 3. The vehicle control device according to claim 2 , wherein the predetermined speed is set near an idle speed of the engine.
That it is constant, the vehicle control equipment according to claim. 4. The method according to claim 1, wherein
In the vehicle control device of Further, whether or not the vehicle is traveling at or above a predetermined speed
Driving state detecting means for detecting The count value of the counting means is determined by the
It is determined that it has exceeded the predetermined value, and the traveling state has been detected.
Means that the vehicle is traveling at or above a predetermined speed
If detected, write the learning value to the non-volatile ROM.
Execute the writing And the count value of the counting means is initialized.
Has been configured to A vehicle control device characterized by the above-mentioned.