JP4135269B2 - Electronic control device and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic control device and a recording medium that can reliably store data relating to, for example, start of an automobile.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, an electronic control device centered on a microcomputer has been used to control an engine of an automobile.
In this electronic control unit, a RAM (normal RAM), a standby RAM, an EEPROM, and the like are employed to store various data.
[0003]
Of these, the RAM is a memory whose data is not guaranteed when the ignition key is off, and the standby RAM is a memory whose data is not guaranteed if the battery voltage drops or the power is cut off due to battery replacement or the like. Is a non-volatile memory capable of holding (writing) data even when the power is turned off.
[0004]
However, the EEPROM has a guaranteed number of times of writing, and if it exceeds that, data may not be written correctly. Therefore, an electronic control device combining the standby RAM and the EEPROM is considered as a data storage means. Yes.
[0005]
This is because a certain amount of data (for example, a first count value for counting the number of start times of the starter of the engine) is stored in a standby RAM with no limit on the number of writes, and each time the first count value reaches a reference value, This is a technique for reducing the number of times of writing to the EEPROM by a method of counting up data (for example, a second count value for calculating the number of start times).
[0006]
[Problems to be solved by the invention]
However, the above-described technique has the following problems.
In other words, in the above-described technique, if the power is cut off due to battery replacement or the like when data is stored in the standby RAM, the data in the standby RAM is lost, so that accurate data cannot be secured in the EEPROM. There's a problem.
[0007]
Specifically, for example, when the first count value in the standby RAM disappears, the second count value stored in the EEPROM becomes smaller than the original value. Therefore, conversion processing is performed from the second count value. Then, when the number of start times is obtained, the value is smaller than the actual number of start times. As a result, the number of starting times is considered to be less than the original number of starting times, and even if the number of starting times becomes excessive, it is not noticed. As a result, starter drive may not be possible, which is not preferable in terms of fail safety.
[0008]
The present invention has been made to solve the above-mentioned problems, and its object is to determine the voltage state for backing up the RAM and to set the data stored in the nonvolatile memory as a safe value. An electronic control device and a recording medium are provided.
[0009]
[Means for Solving the Problems and Effects of the Invention]
(1) The invention of claim 1
A RAM backed up by a power source (for example, a standby RAM) and a writable non-volatile memory (for example, an EEPROM) capable of retaining stored contents even when the power is shut off, and storing the first data in the RAM When the first data reaches a predetermined reference value, the electronic control device changes the second data of the non-volatile memory, and whether or not a guaranteed voltage that guarantees the first data of the RAM is maintained. Voltage state determining means for determining whether or not the guaranteed voltage is not maintained by the voltage state determining means, the second data of the non-volatile memory is set to a predetermined reference value. The gist of the present invention is an electronic control device comprising data changing means for changing data as in the case of reaching the above.
[0010]
For example, when the guaranteed voltage for backing up the RAM is not maintained, for example, when the battery is replaced, the first data in the RAM is not proper (usually cleared). Since the first data stored in the RAM cannot be used, the second data in the nonvolatile memory cannot be appropriately changed based on the first data.
[0011]
Therefore, in the present invention, when it is determined that the guaranteed voltage for guaranteeing the first data of the RAM is not maintained, the second data of the nonvolatile memory is changed to the case where the first data reaches a predetermined reference value. Change in the same way.
As a result, the second data is changed based on the guarantee voltage determination condition regardless of the value of the first data, so that the second data can always be set to a desired safe value. It is. That is, since it can be set as the 2nd data which considered the change of the value of the 1st data, it becomes possible to perform various control more safely based on the 2nd data.
[0012]
(2) The invention of claim 2
A first count value for counting the number of occurrences of a predetermined event is stored in the RAM, and when the first count value reaches a predetermined reference value, the second count value of the nonvolatile memory is counted up. An electronic control unit for determining whether or not the guaranteed voltage for guaranteeing the first count value of the RAM is maintained; and determining that the guaranteed voltage is not maintained by the voltage state judging means. The electronic control device according to claim 1, further comprising: a data changing unit that counts up the second count value of the nonvolatile memory.
[0013]
The present invention exemplifies the invention of claim 1.
In the present invention, when it is determined that the guaranteed voltage for guaranteeing the first count value of the RAM has not been maintained, the second count value of the nonvolatile memory is counted up (incremented). Even in such a case, the second count value can always be set to a larger value (thus, if a larger value is on the safe side), the second count value can be set.
[0014]
For example, when the count value is the number of times the starter is driven, the number of times the starter is driven can be counted more than actually (that is, on the safe side). As a result, it is possible to prevent a starter drive failure by counting the number of times the starter is driven a little.
[0015]
(3) The invention of claim 3
3. The electronic control unit according to claim 1, wherein when the guaranteed voltage is not maintained by the voltage state determination unit, the data stored in the RAM is cleared. The gist.
[0016]
For example, when the guaranteed voltage of the power source for backing up the RAM is not maintained, such as when the battery is replaced, the data in the RAM cannot normally be held as it is. Therefore, for example, after the battery is replaced, a known mirror process is performed to determine whether or not the RAM data is correctly held. If the data is not correct, the RAM data is cleared. This avoids the risk of processing with incorrect data.
[0017]
(4) The invention of claim 4
The gist of the electronic control device according to any one of claims 1 to 3, wherein the voltage state determination means determines whether or not a power source is cut off.
The present invention exemplifies the determination method of the voltage state determination means. Here, for example, when the power source is shut down, for example, when the battery is replaced, the data (first count value) stored in the RAM cannot be held (eg, cleared). The voltage state is determined by
[0018]
(5) The invention of claim 5
After setting a non-zero count value to the second count value of the nonvolatile memory and setting a non-zero count value to the first count value of the RAM, the first count value is cleared (to zero) If it is set, the electronic control device according to claim 4 is characterized in that it is determined that the power supply is shut off.
[0019]
The present invention exemplifies a method for determining when the power supply is shut off.
That is, when the power supply is shut off after the processing routine is started, the first count value of the RAM is cleared, so that it is possible to determine whether or not the power supply is shut off based on the first count value. .
[0020]
(6) The invention of claim 6
The gist of the electronic control device according to any one of claims 1 to 5, wherein the electronic control device is a vehicle-mounted device that controls a vehicle engine.
The present invention exemplifies an object to which an electronic control device is applied.
[0021]
(7) The invention of claim 7
The gist of the electronic control device according to any one of claims 2 to 6, wherein the number of occurrences is a starter driving number.
The present invention exemplifies the types of count values indicating the number of times a predetermined process has been executed. Here, the count value indicates the number of starter drives.
[0022]
In this way, if the starter drive count of the in-vehicle electronic control device, particularly the total starter drive count, which is the total number of start by the ignition key and the automatic start, is stored, it is possible to grasp how much the starter drive count is. . Therefore, when the number of times the starter is driven exceeds the guaranteed value, it is possible to extend the life of the starter by limiting the automatic start of the engine as necessary.
[0023]
The inventions of claims 1 to 7 described above can be applied to engine control by so-called eco-run.
This eco-run is, for example, to automatically stop the engine when the signal is stopped and automatically start the engine when the signal is started in order to reduce fuel consumption and exhaust gas.
[0024]
In such an eco-run state, the number of starter drives increases compared to the case where only the engine is started with a normal ignition key, and in some cases the starter's guaranteed value may be exceeded. This is because, as described above, it is necessary to always grasp the number of starter drives.
[0025]
The electronic control device that performs this control includes: “the engine control includes a stoppable state determination unit that determines whether or not the vehicle engine may be stopped; and a stoppable state determination unit. An affirmative determination, an automatic stop means for automatically stopping the engine, and a startable state determination means for determining whether or not the vehicle engine may be started when the automatic stop means is executed; And an automatic starter that automatically starts the engine when an affirmative determination is made by the startable state determination unit.
[0026]
  (8Claim8The invention of claim 1 to claim 17Of the electronic control device according to any one ofA computer-readable recording of a program for causing a computer to function as each of the meansSummary of recording media.
[0027]
  That is, the function of realizing the electronic control device as described above in a computer system can be provided as a program that is activated on the computer system side, for example. In the case of such a program, for example, a floppy disk(Registered trademark)It can be used by being recorded on a computer-readable recording medium such as a magneto-optical disk, CD-ROM, hard disk, etc., and loaded into a computer system and started as required. In addition, the ROM or backup RAM may be recorded as a computer-readable recording medium, and the ROM or backup RAM may be incorporated into a computer system and used.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example (example) of an embodiment of an electronic control device and a recording medium of the present invention will be described based on the drawings.
(Example)
a) First, the basic configuration of the engine control electronic control device of this embodiment will be described.
[0029]
As shown in FIG. 1, an electronic control device (hereinafter simply referred to as an engine ECU) 1 for engine control according to the present embodiment is a device mainly composed of a microcomputer (shown as CPU in FIG. 1). The so-called eco-run traveling can be controlled. The engine ECU 1 includes a main power supply circuit 5 and a sub power supply circuit 7 as a power supply system in addition to the microcomputer 3, an input circuit 9 and a waveform shaping circuit 11 as an input system, and first and second output systems as an output system. Two output circuits 13 and 15 are provided. Further, a starter monitor circuit 17 and an EEPROM 19 are provided. This will be described in detail below.
[0030]
When the ignition switch (IG switch) 21 is on, the main power supply circuit 5 is supplied with a voltage (+ B) from the battery 23 and supplies a predetermined voltage (Vom) to the input circuit 9 and the microcomputer 3. To supply. The sub power circuit 7 receives a direct voltage (BATT) from the battery 23 and supplies a predetermined voltage (Vos) to the microcomputer 3 even when the IG switch 21 is OFF. is there.
[0031]
The microcomputer 3 includes a ROM 25, a RAM (normal RAM) 27, a standby RAM (hereinafter referred to as SRAM) 29, and the like. Among these, the RAM 27 is a memory that holds contents (data) by supplying voltage from the main power supply circuit 5 while the IG switch 21 is on. The SRAM 29 is a memory that retains contents (for example, data of the number of times of starter driving) by supplying a voltage from the sub power supply circuit 7 even when the IG switch 21 is off.
[0032]
The starter monitor circuit 17 is a circuit that detects the presence or absence of the automatic start of the engine by checking a control signal for driving the starter relay 31 output from the second output circuit 15.
The EEPROM 19 is a non-volatile memory that can retain the contents (for example, data of the starter driving frequency) even when the main power supply and the sub power supply are down, and is supplied with a predetermined voltage (for example, 2 V or more). In some cases, the memory can write data. The number of times data is written to the EEPROM 19 usually has a predetermined limit.
[0033]
Therefore, as shown in an enlarged view in FIG. 2, the microcomputer 3 receives the voltage (Vom) from the main power supply and the voltage (Vos) from the sub power supply, and the EEPROM 19 receives the voltage (Vom) from the main power supply. Data can be exchanged between the SRAM 29 and the EEPROM 19. For example, based on data (first count value) of the starter drive count (start count) stored in the SRAM 29, data (second count value) indicating the starter drive count can be written in the EEPROM 19.
[0034]
In the configuration of FIG. 1 described above, the engine ECU 1 is activated when the IG switch 21 connected to the battery 23 is turned on by operating an ignition key (IG key) (not shown). Further, when the IG key is turned to the ST position of the IG switch 21, the motor 33a of the starter 33 is driven to start the engine.
[0035]
During engine operation, the engine ECU 1 detects vehicle operation signals such as an engine speed signal NE and a vehicle speed signal SPD, and sensor signals such as an intake pipe pressure signal PIM, a throttle opening signal TA, and a coolant temperature signal THW. And outputs control signals for ignition control by the spark plug 35, fuel injection control by the injector 37, and the like.
[0036]
b) Next, the eco-run will be briefly described.
Eco-run means, for example, that the engine is automatically stopped when it stops at a red light, and the engine is automatically started when it starts at a green light, thereby reducing the unnecessary operation period of the engine, saving fuel and reducing exhaust gas. Is a control mode.
[0037]
Accordingly, in the case of eco-run traveling, the number of starter driving operations is increased compared to the case where it is not. However, the starter driving number is set to a predetermined starter driving guarantee value (when the number of starting times exceeds that, the starter 33 is normally driven). There is a limit due to a value that may not be performed;
[0038]
Therefore, it is always checked whether or not the starter drive guarantee value has been reached, and if it exceeds that value, it is necessary to stop the eco-run, so the number of starter drives is counted as described later.
c) Next, processing performed in the engine ECU 1 will be described.
[0039]
In the microcomputer 3 of the engine ECU 1, known mirror processing (calculation data or the like is stored in another storage area, and it is checked whether or not it matches the current same calculation data or the like. In this case, the microcomputer 3 is constantly checked for abnormalities by a process of determining that there is an abnormality), and if an abnormality is detected, the RAM 27 and the SRAM 29 have a function of clearing data.
[0040]
  (1)In this process, the engine start count (that is, the starter drive count) is counted and stored as a first count value in the SRAM 29, and the first count value is a predetermined reference value (for example, 11), the second count value of the EEPROM 19 is counted up (incremented). When the power supply of the battery 23 is interrupted, the second count value is counted up regardless of the value of the first count value.
[0041]
Here, when the IG switch 21 is switched from OFF to ON by the operation of the IG key, the engine ECU 1 is started and the present process is started. The first count value n (n value), the second count value S (S value), and the reference value N (N value) are each set to “0” in advance.
[0042]
As shown in the flowchart of FIG. 3, first, in step 100, the second count value S stored in the EEPROM 19 is determined. That is, it is determined whether or not the second count value S is “0”.
Here, if it is determined that the second count value S is “0”, it is considered that the system is being activated for the first time, and the process proceeds to step 110; otherwise, the process proceeds to step 140.
[0043]
In step 110, a reference value N for counting up the second count value S is set to 11.
In the following step 120, “1” is added to the second count value S (counting up). Therefore, in the first routine, the second count value S is set to “1”.
[0044]
In the following step 130, the first count value n stored in the SRAM 29 is set to “1”, and the process returns to the step 110.
In the second routine, when it is determined in step 100 whether or not the second count value S is “0”, the second count value S has already been processed in step 120 of the previous routine. Therefore, a negative determination is made here, and the routine proceeds to step 140.
[0045]
In step 140, the first count value n is determined. That is, it is determined whether or not the first count value n is “0”. If an affirmative determination is made here, the process proceeds to step 110, while if a negative determination is made, the process proceeds to step 150.
That is, since the first count value n has already been set to “1” in step 130 of the previous routine, or when the count up further proceeds, it becomes “1 or more”, so the first count value n Is not “0”, it is assumed that it is normal (when power is not shut off), and the process proceeds to step 150.
[0046]
In step 150, it is determined whether or not the starter 33 has been driven. If an affirmative determination is made here, the process proceeds to step 160. If a negative determination is made, the process waits until the starter is driven.
The starter drive detection method includes (i) a method of detecting starter drive by the driver's operation of the IG key based on the energization state of the motor 33a, and (ii) automatic start during an eco-run. There is a method of detecting by 17.
[0047]
In step 160, the first count value n for counting the number of times of starter driving is counted up.
In step 170, it is determined whether or not the first count value n has reached the reference value N (= 11). If an affirmative determination is made here, the process proceeds to step 180. If a negative determination is made, the process returns to step 150.
[0048]
In step 170, the second count value S is counted up and written in a predetermined storage area of the EEPROM 19. The second count value S indicates how many times the first count value n has reached the reference value N (in a normal case where the power is not shut off).
[0049]
On the other hand, the case where an affirmative determination is made in step 140 indicates that the power supply of the battery 23 has been interrupted.
That is, after the processing by this routine is started and the second count value S is once set to “1”, the first count value n takes a value in the range of “1 to 11”. Is "0", that is, when the first count value n is cleared, it means that the data in the SRAM 29 is cleared by power-off.
[0050]
If this is shown in the flow of processing, the second count value S, which is the data in the EEPROM 19, is retained even when the power is shut off. Therefore, in the first routine after the power is restored, in step 100, It is determined that the second count value S is not “0”, and the process proceeds to step 140. In step 140, it is determined that the first count value n of the SRAM 29 is “0” (that is, an affirmative determination). Therefore, it can be considered that the power interruption has occurred.
[0051]
In this case, the process proceeds to step 120 through step 110, and the second count value S is counted up.
In other words, when the power is cut off, the first count value n, which is the data of the starter driving count accumulated in the SRAM 29, becomes “0”. If counting is continued with this “0” value being correct, The total starter drive count T to be obtained is less than the actual starter drive count, which is not preferable.
[0052]
Therefore, in this embodiment, in order to count the number of counts higher in anticipation of safety (that is, for fail-safety), when the power is shut off, the second count regardless of the value of the first count value n. The count value S is counted up.
Accordingly, the second count value S necessary for obtaining the integrated value of the starter drive times (total starter drive times) T can be obtained by the above-described processing. Based on 1), the total starter drive count T can be calculated.
[0053]
      T = S × 11 (1)
  That is, by using S × 11, it is possible to obtain the total starter drive count T that is shifted to the safe side from the actual total starter drive count.
  (2)Starter Drive Count Confirmation Process This process is a process for determining whether or not the starter drive count is equal to or greater than the starter operation guarantee count (starter drive guarantee value).
[0054]
When the IG switch 21 is switched from off to on by the operation of the IG key, the engine ECU 1 is started and this processing is started.
As shown in the flowchart of FIG. 4, first, in step 200, the second count value S calculated by the processing of FIG. 3 and the first count value n stored in the SRAM 29 up to now are used, and the following formula (2 ) To calculate the total starter drive count T.
[0055]
In this equation (2), the first count value n is further added to the above equation (1), and this is because a more accurate total starter driving frequency T is obtained by adding the value up to now. However, since the number of all starter drivings is set to be a safe side this time, n may be omitted.
[0056]
T = S × 11 + n (2)
In the following step 210, it is determined whether or not the total starter drive count T is equal to or greater than the starter drive guarantee value of 130,000. If an affirmative determination is made here, the process proceeds to step 220. If a negative determination is made, the process returns to step 200.
[0057]
In step 220, since the total starter drive count T is equal to or greater than the starter drive guarantee value, the eco-run is stopped and the present process is temporarily terminated.
As a result, when the starter drive count increases, the eco-run is stopped, so that the subsequent starter drive count can be reduced.
[0058]
d) Next, the operation by the above-described processing will be described with reference to the timing chart of FIG.
At time t1, when the IG switch 21 is switched from off to on by operating the IG key, a voltage (+ B) is supplied from the battery 23 to the engine ECU 1. At this time, as described above, the second count value S of the EEPROM 19 is set to “1” in the first routine of FIG.
[0059]
Accordingly, while the IG switch 21 is on, the first count value n of the SRAM 29 is incremented every time starter driving is performed.
When the first count value n reaches the reference value N at time t2, the second count value S is counted up and the first count value n returns to “1”.
[0060]
Here, for example, if the battery 23 is replaced while the second count value S is set to “2”, the backup of the voltage (+ B, BATT) by the battery 23 is lost (time t 3). The data of is cleared. Accordingly, the first count value n is “0”.
[0061]
At time t4, when the battery 23 is connected and the power is restored, the second count value S is incremented and set to "3" even though the first count value n is "0". .
Thereafter, as long as voltage is supplied, the first count value n is similarly incremented every time starter driving is performed.
[0062]
e) In the present embodiment, the following effects can be obtained by the processing and operation described above.
In this embodiment, when the first count value n stored in the SRAM 29 (indicating the number of times of starter driving) reaches the reference value N as in the prior art, the second count value S of the EEPROM 19 is not simply counted up. The second count value S is also counted up when it is determined that the power supply is cut off.
[0063]
Accordingly, since the second count value S is set to a higher value, the total starter drive count T is also always set to a higher value (accordingly, a safe value) than the actual starter drive count.
That is, when the total starter drive count T is set to a higher value, when the total starter drive count T is compared with the starter drive guarantee value, the actual starter drive count approaches the starter drive guarantee value. It can be detected reliably. Therefore, the actual starter driving frequency does not exceed the starter driving guarantee value, and the starter driving can be reliably performed.
[0064]
Furthermore, in this embodiment, when the total starter drive count T is equal to or greater than the starter drive guarantee value, the eco-run is stopped, so that the degree of increase in the subsequent starter drive count can be reduced. . That is, as the starter drive count exceeds the starter drive guarantee value, the possibility that the start operation cannot be performed favorably increases, so the eco-run where the starter drive count increases is stopped. Thereby, after the eco-run is canceled, only the engine is started by the IG key, so the reliability of the starter 33 can be ensured.
[0065]
  Needless to say, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the scope of the present invention.
  (1) For example, the present invention is not limited to the engine ECU, and the above-described processing is executed.programIt can also be applied to a recording medium that stores.
[0066]
  This recording medium includes microchips and floppy disks.(Registered trademark)And various recording media such as a hard disk and an optical disk. That is, the processing of the electronic control device described above can be executed.ProgramThere is no particular limitation as long as it is memorized.
[0067]
(2) In the above embodiment, the second count value of the EEPROM is counted up when the power is cut off, such as when the battery is replaced, but the phenomenon that the first count value of the SRAM is cleared is Since this also occurs when the voltage for backing up the SRAM drops below the voltage that can hold the data, the second count value of the EEPROM may be counted up when such a drop in voltage occurs. .
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a schematic configuration of an electronic control device according to an embodiment.
FIG. 2 is an explanatory diagram illustrating an enlarged main part of an electronic control device according to an embodiment.
FIG. 3 is a flowchart illustrating a starter drive count storage process according to the embodiment.
FIG. 4 is a flowchart illustrating starter driving frequency confirmation processing according to the embodiment.
FIG. 5 is a timing chart showing an operation by processing of an embodiment.
[Explanation of symbols]
1 ... Electronic control unit
3 ... Microcomputer
5 ... Main power circuit
7 ... Sub power circuit
17 ... Starter monitor circuit
19… EEPROM
21 ... Ignition switch (IG switch)
23 ... Battery 23
27 ... Normal RAM (RAM)
29 ... Standby RAM (SRAM)
33 ... Starter

Claims (8)

RAM backed up by a power supply,
Writable non-volatile memory that can retain stored contents even when the power is turned off,
With
An electronic control device that stores first data in the RAM and changes the second data of the nonvolatile memory when the first data reaches a predetermined reference value,
Voltage state determination means for determining whether or not a guaranteed voltage for ensuring the first data of the RAM is maintained;
Data that changes the second data of the non-volatile memory in the same manner as when the first data reaches a predetermined reference value when the voltage state determining means determines that the guaranteed voltage is not maintained. Change means,
An electronic control device comprising: A first count value for counting the number of occurrences of a predetermined event is stored in the RAM, and when the first count value reaches a predetermined reference value, the second count value of the nonvolatile memory is counted up. An electronic control unit, a voltage state determination means for determining whether or not a guaranteed voltage for ensuring the first count value of the RAM is maintained;
If the voltage state determination means determines that the guaranteed voltage has not been maintained, the data change means for counting up the second count value of the nonvolatile memory;
The electronic control device according to claim 1, further comprising: 3. The electronic control device according to claim 1, wherein when the voltage state determination unit determines that the guaranteed voltage is not maintained, the data stored in the RAM is cleared. The electronic control device according to claim 1, wherein the voltage state determination unit determines whether or not a power source is cut off. When the count value other than 0 is set to the second count value of the nonvolatile memory and the count value other than 0 is set to the first count value of the RAM, and then the first count value is cleared 5. The electronic control device according to claim 4, wherein it is determined that the power supply has been shut off. The electronic control device according to claim 1, wherein the electronic control device is a vehicle-mounted device that performs engine control of a vehicle. The electronic control device according to claim 2, wherein the number of occurrences is a starter driving number. 8. A computer-readable recording medium on which a program for causing a computer to function as each means of the electronic control device according to claim 1 is recorded.

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