JP5664454B2 - Electronic control device for vehicle - Google Patents

Description

  The present invention relates to a vehicular electronic control device that stores information in a nonvolatile memory capable of data rewriting.

  As a vehicle electronic control device (hereinafter also referred to as a vehicle ECU) that is mounted on a vehicle and controls an engine or the like, information such as total travel distance, MIL integrated distance, freeze frame data, and permanent DTC (Diagnostic Trouble Code) Some (hereinafter referred to as non-volatile memory write target data) are stored in a non-volatile memory (for example, EEPROM) that can be rewritten.

  Even if the ignition switch is turned off, the vehicle ECU maintains the supply of the operating voltage to the microcomputer until the microcomputer in the vehicle ECU completes all the processes and permits the power supply to be cut off. A main relay is provided.

  Conventionally, the vehicle ECU temporarily stores the data to be written into the nonvolatile memory in a volatile memory such as a RAM, and the supply of the operation voltage by the main relay is maintained after the ignition key is turned off. The nonvolatile memory write target data is configured to be written in the nonvolatile memory (see, for example, Patent Documents 1 and 2).

  In recent years, for the purpose of reducing fuel consumption and exhaust gas, the engine is automatically stopped when the vehicle is stopped and the engine is not required to be driven (for example, waiting for a signal). A vehicle having an idle stop function in which an engine is automatically restarted when an operation intended to resume is performed.

Japanese Patent Laid-Open No. 11-141391 Japanese Patent No. 3960212

  However, in the techniques described in Patent Documents 1 and 2, when an abnormality occurs in the main relay and the operation voltage supply is not maintained after the ignition key is turned off, the nonvolatile memory write target data Is not written to the non-volatile memory, and there is a possibility that the update of the data to be written to the non-volatile memory may occur.

  In addition, in a vehicle having an idle stop function, the number of engine restarts (that is, the number of crankings) is increased compared to a vehicle not having an idle stop function. Therefore, the reset of the ECU occurs due to the battery voltage drop due to cranking at the time of restart, and the nonvolatile memory write target data stored in the volatile memory in the ECU disappears before being stored in the nonvolatile memory There is a risk that this will happen.

  The present invention has been made in view of these problems, and an object thereof is to provide a technique for suppressing omission of update of data stored in a nonvolatile memory.

The vehicle electronic control device according to claim 1 , which has been made to achieve the above object, stops the engine when a preset automatic stop condition is established, and establishes a preset automatic start condition after the engine is stopped. Then, it is mounted on a vehicle having an idle stop function for restarting the engine, and includes a volatile memory capable of reading and writing data, and a nonvolatile memory capable of rewriting the stored contents, and the storage execution means automatically stops. If the power supply to the vehicle electronic control device is maintained after the condition is satisfied and until the engine is restarted due to the establishment of the automatic start condition, the data stored in the volatile memory Of these, the nonvolatile memory storage target data, which is preset data as data to be stored in the nonvolatile memory, is stored in the nonvolatile memory. And stores it in.

  In the vehicle electronic control device configured as described above, the nonvolatile memory storage target data is stored in the nonvolatile memory before the restart by the idle stop function. For this reason, the nonvolatile memory storage target data stored in the volatile memory is stored in the nonvolatile memory when the vehicle electronic control device is reset due to the battery voltage drop due to the cranking at the restart of the idle stop function. Occurrence of the situation of disappearing before being performed can be suppressed.

  Furthermore, if the vehicle travels after the ignition switch is turned on and the idle stop function is activated before the ignition switch is turned off, the nonvolatile memory storage target data stored in the volatile memory is stored in the nonvolatile memory. Is remembered. For this reason, even if an abnormality occurs in the main relay and the nonvolatile memory storage target data stored in the volatile memory cannot be stored in the nonvolatile memory after the ignition switch is turned off, it is stored in the volatile memory. It is possible to suppress the occurrence of the situation where the stored nonvolatile memory storage target data is lost before being stored in the nonvolatile memory.

Moreover, Te vehicle electronic control unit smell of claim 1, memorize execution means after the establishment of the automatic stop condition, until the engine is stopped by the occurrence of an automatic stop condition, the non-volatile memory storage target stores data in a nonvolatile memory.

  According to the vehicle electronic control device configured as described above, since the engine is not stopped, the idle stop function is not restarted, that is, the vehicle electronic control device is not reset due to cranking. In this state, the nonvolatile memory storage target data can be stored in the nonvolatile memory.

It is a block diagram which shows ECU1 and the peripheral device of ECU1. It is a flowchart which shows the idle stop control process of 1st Embodiment. It is a flowchart which shows the idle stop control process of 2nd Embodiment.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram illustrating an electronic control device (hereinafter referred to as ECU) 1 and peripheral devices of the ECU 1 according to the present embodiment.

  The ECU 1 is mounted on a vehicle and includes a microcomputer 21, an EEPROM 22, an input circuit 23, a main relay drive circuit 24, and a starter drive circuit 25, as shown in FIG. When the ignition switch (IGSW) 2 of the vehicle is turned on, the ECU 1 starts operation by turning on the main relay 3 for power supply provided outside the ECU 1 and supplying the battery voltage VB from the battery 4. To do.

  Of these, the microcomputer 21 is a well-known microcomputer comprising a CPU 31, ROM 32, RAM 33, I / O 34 and a bus line connecting these components, and controls the engine based on programs stored in the ROM 32 and RAM 33. Various processes for executing the above are executed.

The EEPROM 22 is a nonvolatile memory capable of rewriting data, and is connected to the microcomputer 21 so that data can be input / output.
The input circuit 23 causes the microcomputer 21 to input various signals from the outside for controlling the engine. Specifically, an ignition switch signal indicating the on / off state of the IGSW 2, a starter switch signal indicating the on / off state of the starter switch (STASW) 5 for starting the engine, and a vehicle brake pedal are depressed. A stop lamp signal indicating the on / off state of the stop lamp switch 6 that sometimes turns on and turns on the stop lamp, a detection signal from the vehicle speed sensor 7 that detects the vehicle speed, and the like are input to the microcomputer 21 via the input circuit 23. Is done.

  The main relay drive circuit 24 outputs a relay drive signal for turning on the main relay 3 based on the relay control signal from the microcomputer 21. Specifically, the microcomputer 21 outputs a control signal for instructing the output of the drive signal from the time when the IGSW 2 is switched from the on state to the off state until the processing to be executed by the microcomputer 21 after the IG is turned off. 24. As a result, the main relay 3 is turned on for a predetermined period after the IG is turned off.

  The starter drive circuit 25 outputs a starter drive signal for driving the starter 8 that starts the engine upon receiving the supply of the battery voltage VB from the battery 4 based on the starter control signal from the microcomputer 21.

  In the ECU 1 configured as described above, the microcomputer 21 automatically stops the engine when a preset idle stop condition is satisfied, and restarts the engine when a preset idle stop return condition is satisfied. Execute. The idle stop condition in the present embodiment is that the vehicle speed based on the detection signal from the vehicle speed sensor 7 is 0 km / h, and the stop lamp signal indicates the on state. In addition, the idle stop return condition in the present embodiment is that the stop lamp signal is in an off state.

  Further, the microcomputer 21 determines whether or not the above-mentioned idle stop return condition is satisfied after the engine is stopped by the idle stop control. The restart request processing for clearing the restart request flag Fr when the condition is not satisfied is configured to be executed every time a preset processing cycle (8 ms in the present embodiment) elapses.

  Here, the procedure of the idle stop control process will be described with reference to FIG. FIG. 2 is a flowchart showing the idle stop control process. This idle stop control process is a process repeatedly executed while the microcomputer 21 is activated (powered on).

  When the idle stop control process is executed, the microcomputer 21 first determines in S10 whether or not an idle stop flag Fi indicating whether or not the idle stop is being performed is set. If the idle stop flag Fi is not set (S10: NO), it is determined in S20 whether a preset idle stop condition is satisfied.

  Here, when the idle stop condition is not satisfied (S20: NO), the idle stop control process is temporarily ended. On the other hand, if the idle stop condition is satisfied (S20: YES), in S30, a memory update condition set in advance to determine whether data can be written to the EEPROM 22 is satisfied. Judge whether or not. In the present embodiment, the memory update condition is that the battery voltage VB is equal to or higher than a predetermined determination value.

  Here, when the memory update condition is not satisfied (S30: NO), the idle stop control process is temporarily ended. On the other hand, when the memory update condition is satisfied (S30: YES), the update is performed on the RAM 33 of the microcomputer 21 among the write target data set in advance as data to be written to the EEPROM 22 in S40. In addition, it is determined whether or not there is data in which this update is not reflected in the EEPROM 22 (hereinafter referred to as update-unreflected write target data). In the present embodiment, the data to be written is freeze frame data, immobility identification code, permanent DTC, total travel distance, MIL integrated distance, electronic throttle fully closed learning value, and the like.

  Here, when there is no update unreflected write target data (S40: NO), the idle stop control process is temporarily ended. On the other hand, if there is update-unreflected write target data (S40: YES), the update-unreflected write target data is written to the EEPROM 22 in S50. In S60, the engine is automatically stopped. In S70, an idle stop flag Fi is set, and the idle stop control process is temporarily terminated.

  If the idle stop flag Fi is set in S10 (S10: YES), it is determined in S80 whether the restart request flag Fr is set. If the restart request flag Fr is not set (S80: NO), it is determined in S90 whether there is data that has not been updated yet, as in S40.

  If there is no update-unreflected write target data (S90: NO), the idle stop control process is temporarily terminated. On the other hand, if there is update-unreflected write target data (S90: NO), the required time for writing the update-unreflected write target data to the EEPROM 22 (hereinafter referred to as data write time) is calculated in S100. To do. Specifically, the data writing time is calculated by multiplying the time required for writing 1-byte data into the EEPROM 22 (hereinafter referred to as unit writing required time) by the number of bytes of the update-unreflected write target data. . In this embodiment, the unit writing required time is set to 2 ms. For this reason, for example, when the data amount of the update unreflected write target data is 10 bytes, the data write time is calculated as 20 ms. However, the data writing time is calculated with respect to data (for example, total travel distance) that is not problematic even if it is divided into 1-byte data and written to the EEPROM 22 among the update-unreflected data to be written.

  Thereafter, in S110, it is determined whether or not the data write time calculated in S100 is shorter than the processing cycle of restart request processing (8 ms in this embodiment). Here, when the data write time is shorter than the processing cycle of the restart request process (S110: YES), in S120, all the update unreflected write target data is written to the EEPROM 22, and the idle stop control process is temporarily performed. finish. On the other hand, if the data write time is equal to or longer than the restart request processing cycle (S110: NO), in S130, the amount of data that can be written within the restart request processing cycle (in this embodiment, (4 bytes) unupdated write target data is written to the EEPROM 22 and the idle stop control process is temporarily terminated.

  If the restart request flag Fr is set in S80 (S80: YES), the engine is restarted in S140, and then the idle stop flag Fi is cleared in S150, and the idle stop is performed. The control process is temporarily terminated.

  The ECU 1 configured as described above has an idle stop function of automatically stopping the engine when a preset idle stop condition is satisfied and restarting the engine when a preset idle stop return condition is satisfied after the engine is stopped. A RAM 33 that is a volatile memory that is mounted on a vehicle and can read and write data, and an EEPROM 22 that is a non-volatile memory that can rewrite the stored contents. Before the engine is restarted due to the satisfaction of the condition, write target data set in advance as data to be written in the EEPROM 22 among the data stored in the RAM 33 is stored in the EEPROM 22 (S10 to S50, S80 to S130). .

  In the ECU 1 configured as described above, the write target data is stored in the EEPROM 22 before restart by the idle stop function. For this reason, when the ECU 1 is reset due to the battery voltage drop due to the cranking at the restart of the idle stop function, the write target data stored in the RAM 33 is lost before being stored in the EEPROM 22. Can be suppressed.

  Further, if the vehicle travels after IGSW 2 is turned on and the idle stop function is activated after the IGSW 2 is turned off, the write target data stored in the RAM 33 is stored in the EEPROM 22. For this reason, even if an abnormality occurs in the main relay 3 and the non-volatile memory storage target data stored in the volatile memory cannot be stored in the non-volatile memory after the IGSW 2 is turned off, it is stored in the volatile memory. It is possible to suppress the occurrence of the situation where the stored nonvolatile memory storage target data is lost before being stored in the nonvolatile memory.

  Further, the write target data is stored in the EEPROM 22 after the idle stop condition is established and before the engine is stopped due to the establishment of the idle stop condition (S10 to S50). That is, since the engine is not stopped, the write target data can be stored in the EEPROM 22 in a state where the idle stop function is not restarted, that is, in a stable state where the ECU 1 is not reset by cranking.

  Further, the write target data may be stored in the EEPROM 22 between the time when the engine is stopped due to the establishment of the idle stop condition and the time when the engine is restarted due to the establishment of the idle stop return condition (S80 to S130). ). That is, since it is before the engine is restarted, it is possible to avoid the occurrence of a situation in which cranking at the time of restart occurs while the write target data is being written to the EEPROM 22. In other words, the write target data can be written to the EEPROM 22 without being affected by the power supply interruption and noise caused by the cranking.

  In addition, it is determined whether or not the idle stop return condition is satisfied by the idle stop function every preset processing cycle (8 ms), and all the write target data stored in the EEPROM 22 is stored within the processing cycle. The data is divided within the amount of data that can be stored in the EEPROM 22, and the divided write target data is stored in the EEPROM 22 (S100 to S130). Thereby, since the writing of the divided write target data can be completed before the idle stop return condition determined for each processing cycle is satisfied, the write target data is being written to the EEPROM 22. Occurrence of a situation in which cranking occurs at the time of restart can be avoided.

  Further, the data to be written in the RAM 33 is stored in the nonvolatile memory among the write target data (S40, S90). As a result, the amount of data to be written to the EEPROM 22 can be reduced and the time for writing data to the EEPROM 22 can be shortened as compared with the case where all of the write target data is stored in the EEPROM 22 at once. Degradation of the EEPROM 22 due to an increase in the data write amount can be suppressed.

  In the embodiment described above, the ECU 1 is the vehicle electronic control device according to the present invention, the RAM 33 is the volatile memory according to the present invention, the EEPROM 22 is the non-volatile memory according to the present invention, and the processes of S10 to S50 and S80 to S130 are stored in the present invention. The execution means and the idle stop condition are the automatic stop condition in the present invention, the idle stop return condition is the automatic start condition in the present invention, and the write target data is the nonvolatile memory storage target data in the present invention.

(Second Embodiment)
The second embodiment of the present invention will be described below. In the second embodiment, only parts different from the first embodiment will be described.

  The ECU 1 of the second embodiment is the same as that of the first embodiment except that the idle stop control process is changed. FIG. 3 is a flowchart showing an idle stop control process according to the second embodiment.

  As shown in FIG. 3, the idle stop control process of the second embodiment is the same as that of the first embodiment except that the processes of S100 to S130 are omitted and the process of S210 is added.

  That is, when it is determined in S90 that there is update-unreflected write target data (S90: YES), one byte of update-unreflected write target data is written to the EEPROM 22 in S210, and idle stop control processing is performed. Is temporarily terminated.

  In the ECU 1 configured as described above, the operation is interrupted when the idle stop return condition is satisfied while the write target data is being stored in the EEPROM 22. As a result, it is possible to avoid the occurrence of a situation in which cranking occurs at the time of restart while the write target data is being written to the EEPROM 22.

As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, As long as it belongs to the technical scope of this invention, a various form can be taken.
For example, in the above-described embodiment, a process for storing the write target data in the EEPROM 22 after the idle stop condition is established and before the engine is stopped due to the establishment of the idle stop condition (hereinafter referred to as a pre-engine stop writing process). The process of storing the write target data in the EEPROM 22 after the engine is stopped due to the establishment of the idle stop condition and before the engine is restarted due to the establishment of the idle stop return condition (hereinafter referred to as a pre-restart writing process). However, it is also possible to execute either one of the pre-engine stop writing process and the pre-restart writing process.

  DESCRIPTION OF SYMBOLS 1 ... ECU, 2 ... IGSW, 3 ... Main relay, 4 ... Battery, 5 ... STASW, 6 ... Stop lamp switch, 7 ... Vehicle speed sensor, 8 ... Starter, 21 ... Microcomputer, 22 ... EEPROM, 23 ... Input circuit, 24 ... Main relay drive circuit, 25 ... Starter drive circuit, 31 ... CPU, 32 ... ROM, 33 ... RAM, 34 ... I / O

Claims (1)

Electronic control for a vehicle mounted on a vehicle having an idle stop function for stopping the engine when a preset automatic stop condition is satisfied and restarting the engine when a preset automatic start condition is satisfied after the engine is stopped A device,
A volatile memory capable of reading and writing data;
Non-volatile memory capable of rewriting stored contents,
When the power supply to the electronic control unit for the vehicle is maintained between the time when the automatic stop condition is satisfied and the time when the engine is restarted when the automatic start condition is satisfied, the volatile memory Storage execution means for storing, in the nonvolatile memory, nonvolatile memory storage target data that is preset as data to be stored in the nonvolatile memory among the data stored in
The storage execution means
The vehicle electronic control characterized in that the nonvolatile memory storage target data is stored in the nonvolatile memory after the automatic stop condition is satisfied and before the engine is stopped due to the establishment of the automatic stop condition. apparatus.

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