JP2015162102A - Vehicle control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control apparatus configured to improve the function of holding data stored in a memory, while properly responding to a fault of the memory.SOLUTION: A microcomputer 2 controlling devices of a vehicle includes a built-in EEPROM 5 and an external EEPROM 6 arranged outside the microcomputer 2. The microcomputer 2 diagnoses a fault in each of a built-in nonvolatile memory 5 and an external nonvolatile memory 6, and stores the results of diagnosing the nonvolatile memories on the other nonvolatile memories in a complementary manner. When both nonvolatile memories are normal, data are written on the built-in EEPROM, and the data stored in the built-in EEPROM are written on the external EEPROM periodically. When one of the EEPROM fails, data in the other EEPROM is used for control.

Description

  The present invention relates to a vehicle control device that controls each device of a vehicle.

  In Patent Document 1, when the flash memory provided in the semiconductor device deteriorates, the data of the deteriorated area is stored in a save area constituted by a nonvolatile memory, and control is performed using the data stored in the save area. An apparatus for performing is disclosed.

JP 2006-65384 A

  However, in the technique described in Patent Document 1, when it is attempted to store the data in the save area by detecting the deterioration of the flash memory, the data cannot be stored if the save area has failed. In addition, even when a failure in the save area is detected, the diagnosis result data indicating that there is a failure cannot be stored and held, so that the recognition that there is a failure is delayed and it is difficult to cope with (repair) the failure. there were.

  The present invention has been made paying attention to the above-mentioned problems, and has as its object to provide a vehicle control device that improves the retention function of data stored in a memory and can cope with a memory failure well. To do.

  To achieve the above object, a vehicle control device according to the present invention includes a built-in nonvolatile memory built in a control device that controls each device of the vehicle, and an external nonvolatile memory arranged outside the control device. And the control device diagnoses whether there is an abnormality in the built-in nonvolatile memory and the external nonvolatile memory, and stores the diagnosis result of each nonvolatile memory in a complementary manner in the other nonvolatile memory. Features.

  According to the present invention, the abnormality diagnosis result of the other nonvolatile memory is stored in the built-in nonvolatile memory and the external nonvolatile memory, respectively, so that when there is an abnormality in the data write destination memory, the normal memory The data retention performance that can retain data even when the power supply from the power supply is cut off or the supply amount is reduced can be improved, and the failure response function can be improved by retaining abnormal data, which improves the vehicle control performance. improves.

It is a block diagram which shows schematic structure of the control apparatus for vehicles which concerns on embodiment of this invention. It is a 1st flowchart which shows the data writing control in an apparatus same as the above. The schematic diagram which shows the processing state of each memory when abnormality arises in the built-in EEPROM and external EEPROM in an apparatus same as the above. It is a 2nd flowchart which shows data write control same as the above. It is a time chart for demonstrating the control state when a power supply voltage falls at the time of cranking.

Embodiments of the present invention will be described below with reference to the drawings.
As shown schematically in FIG. 1, an ECU (Electronic Control Unit) 1 includes a microcomputer (hereinafter abbreviated as a microcomputer) 2 that controls each device of the vehicle. The microcomputer 2 includes a power source 3 such as a battery. The power supply voltage Vb is applied through the power supply relay (or ignition switch) 4.

  The microcomputer 2 includes a built-in nonvolatile memory (built-in EEPROM) 5 as a memory for storing control data calculated by the microcomputer 2. The data content stored in the built-in EEPROM 5 is stored even when the power supply from the power source 3 to the microcomputer 2 is cut off, such as when the ignition switch is OFF.

  The ECU 1 includes an external nonvolatile memory (external EEPROM) 6 connected to the microcomputer 2 outside the microcomputer 2 and stores control data calculated by the microcomputer 2. The external EEPROM 6 is not connected to the power supply 3 and can hold stored data without requiring power supply.

In the present embodiment, the microcomputer 2 first writes the calculated data such as control data into the built-in EEPROM 5 and then writes the data stored in the built-in EEPROM 5 to the external EEPROM 6 at a predetermined cycle.
Further, the microcomputer 2 diagnoses the presence or absence of abnormality of these EEPROMs when the power supply 3 is started up and when data is written to the built-in EEPROM 5 and the external EEPROM 6, and the diagnosis result of each EEPROM is complemented to the other EEPROM. Memorize.

FIG. 2 shows a second flow showing data write control of the microcomputer 2.
In step S1, it is determined whether or not the power supply relay 4 is turned from OFF to ON, that is, when the power supply is turned on.
If it is determined that the power is turned on, the process proceeds to step S2 to diagnose the presence / absence of abnormality in the built-in EEPROM 5 and the external EEPROM 6.

  In step S3, the diagnosis result of each EEPROM is complementarily written (stored) in the other EEPROM. When diagnosed as “abnormal”, it is preferable to notify the driver of the “abnormal” by turning on an alarm lamp or the like so as to prompt prompt repair. The diagnosis result “normal” may be initialized and rewritten to the diagnosis result “abnormal” when the diagnosis is “abnormal”.

In step S4, it is determined whether a request for writing the data calculated by the microcomputer 2 to the EEPROM has occurred.
When it is determined that a data write request has occurred, the process proceeds to step S5, and the diagnostic result of the built-in EEPROM 5 is read from the external EEPROM 6 prior to writing the data to the built-in EEPROM 5.

If the diagnosis result of the built-in EEPROM 5 is “normal”, the process proceeds to step S6, and before the data is written into the built-in EEPROM 5 (or in parallel with the write operation), the presence or absence of abnormality in the built-in EEPROM 5 is newly diagnosed. To do.
In step S7, a new diagnosis result of the built-in EEPROM 5 in step S6 is determined. If the diagnosis result is “normal”, the process proceeds to step S8, and the latest control data is written to the built-in EEPROM 5 (written to the built-in EEPROM 5). The same kind of data that has been updated is updated with the latest data (the same applies hereinafter. If the writing is started concurrently with the diagnosis, the writing is completed).

  On the other hand, when the diagnosis result of the built-in EEPROM 5 read from the external EEPROM 6 is “abnormal” in step S5, the process proceeds to step S9 and the latest data is written to the normal external EEPROM 6 (the data has been written to the external EEPROM 6). Update the same kind of data with the latest data.

If the new diagnosis result of the built-in EEPROM 5 in step S6 is “abnormal”, the process proceeds to step S10, and the diagnosis result that the built-in EEPROM 5 is “abnormal” and the latest data are written in the external EEPROM 6.
With the above configuration, as shown in FIG. 3, even if an abnormality occurs in one of the built-in EEPROM 5 or the external EEPROM 6, data can be written to the other normal EEPROM based on the diagnosis result, and the normal EEPROM can be written. Control using the latest data is possible.

In addition, for example, a conventional configuration including a RAM and one EEPROM, and writing the abnormal information data to the RAM when the EEPROM fails, can be temporarily switched off when the ignition switch is turned off or cranked as described later. When the value of the error is greatly reduced, the abnormality information data stored in the RAM may be lost, and the abnormal state may not be recognized and the normal state may not be restored.
On the other hand, according to the embodiment of the present invention, even when the power supply is interrupted as described above and when a large voltage drop occurs in the cranking, the abnormality information data of the EEPROM in which the abnormality has occurred is normal. Held in EEPROM. Therefore, the abnormality information data can be recognized by a warning or the like to be repaired and promptly returned to the normal state.

Briefly, as described above, normally, while abnormality diagnosis of both EEPROMs is performed, when both are normal, data is written to one EEPROM, and when one EEPROM is abnormal, the abnormality information is stored in the other EEPROM. At the same time, the EEPROM may be switched so as to write data.
In the present embodiment, in addition to the above configuration, data stored in the built-in EEPROM 5 is written to the external EEPROM 6 at a constant cycle.

FIG. 4 is a second flow showing data writing to the external EEPROM 6 that is periodically executed.
This flow is performed in a sufficiently short cycle so that good responsiveness can be ensured even when the microcomputer 2 calculates the latest data and then uses the data written in the external EEPROM 6 for control.

In step S11, the diagnosis result of the external EEPROM 6 is read from the built-in EEPROM 5 to determine whether there is an abnormality.
If it is determined that the diagnosis result is “normal”, the process proceeds to step S 12, and the data stored in the built-in EEPROM 5 is written to the external EEPROM 6.
If it is determined in step S11 that the diagnosis result of the external EEPROM 6 is “abnormal”, the process proceeds to step S13, and data writing from the built-in EEPROM 5 to the external EEPROM 6 is prohibited.

With this configuration, the data stored redundantly in the internal EEPROM 5 and the external EEPROM 6 can be stored using the data stored redundantly from the other EEPROM even when one EEPROM fails. Accurate control can be performed.
For example, an external EEPROM 6 having a larger capacity than that of the built-in EEPROM 5 is provided, and when both the memories 5 and 6 are in normal normal control, control is performed using data stored in the external EEPROM 6, and an abnormality occurs in the external EEPROM 6. In this case, the control may be switched to the control using the data stored in the built-in EEPROM 5.

In this way, it is possible to obtain high-precision control performance and data retention performance at low cost by using the microcomputer 2 having the built-in EEPROM 5 having a relatively small capacity and the external EEPROM 6 having a large capacity.
Further, by shifting the data writing timing between the built-in EEPROM and the external EEPROM and periodically writing a plurality of data stored in the built-in EEPROM to the external EEPROM, the write processing load can be greatly reduced.

  FIG. 5 shows a state where the power supply voltage Vb is temporarily greatly reduced during cranking. When the power supply voltage Vb is equal to or higher than the writable voltage Vbp, the data that has been written is held without disappearing even if the power supply voltage Vb falls below the writable voltage Vbp. In addition, writing cannot be performed at a voltage lower than the writable voltage Vbp, but newly calculated data is written to the EEPROM after the voltage reaches the writable voltage Vbp or higher.

  In the example shown in FIG. 4, the data written in the built-in EEPROM 5 immediately before the power supply voltage Vb falls below the writable voltage Vbp is restored after the power supply voltage Vb falls below the possible voltage Vbp, The data is written from the built-in EEPROM 5 to the external EEPROM 6.

  In the above embodiment, the data calculated by the microcomputer 2 is written in the built-in EEPROM and then the data stored in the built-in EEPROM is written in the external EEPROM. Conversely, after the data is written in the external EEPROM. The internal EEPROM may be written, or the internal EEPROM and the external EEPROM may be written at the same timing.

  In the above embodiment, when an abnormality occurs in one EEPROM, the data is written in the other EEPROM. However, an area where the abnormality of the EEPROM has occurred or a block including the area may be detected. In that case, the data may be written into a region where an abnormality has occurred or a normal region other than a block including the region.

  Further, in an ECU including a main microcomputer and a sub-microcomputer that monitors the main microcomputer, the main microcomputer may include a built-in EEPROM, and the sub-microcomputer may include an external EEPROM.

Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) In the vehicle control device according to claim 2 or 3, the control device writes data in the one non-volatile memory, and then transfers the data stored in the one non-volatile memory to the other non-volatile memory. A vehicle control device that writes in a non-volatile memory.
According to the above configuration, the write processing load can be reduced by shifting the timing of writing data to the two nonvolatile memories.

(B) The vehicle control device according to claim 2, claim 3 or (a), wherein the capacity of the external nonvolatile memory is larger than the capacity of the built-in nonvolatile memory.
According to the above configuration, high-precision control performance and data retention performance can be obtained at low cost by using a microcomputer including a built-in nonvolatile memory having a relatively small capacity and an external nonvolatile memory having a large capacity.

  DESCRIPTION OF SYMBOLS 1 ... ECU (Electronic Control Unit), 2 ... Microcomputer, 3 ... Power supply, 4 ... Power supply relay, 5 ... Built-in EEPROM, 6 ... External EEPROM

Claims (3)

A built-in nonvolatile memory built in a control device for controlling each device of the vehicle;
An external non-volatile memory disposed outside the control device,
The control device diagnoses whether there is an abnormality in the built-in nonvolatile memory and the external nonvolatile memory, and stores the diagnosis result of each nonvolatile memory in a complementary manner in the other nonvolatile memory, The vehicle control device.   The vehicle control device according to claim 1, wherein at least the external nonvolatile memory stores a part of the contents stored in the built-in nonvolatile memory in an overlapping manner.   3. The control device according to claim 2, wherein when the one non-volatile memory is diagnosed as abnormal, the control device performs control using data stored in the other non-volatile memory. 4. Vehicle control device.