JP2010048158A - Controller of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain the idle rotation speed by reducing the number of times of rewriting of nonvolatile memory so as to prevent the number of times of rewriting of the nonvolatile memory from exceeding the upper limit. <P>SOLUTION: The controller is equipped with a control unit 10 for determining whether a predetermined feedback control condition is satisfied based on the operation state of a vehicle obtained from sensors 1-6, for comparing an actual rotation speed and a target rotation speed in the case where the condition is satisfied, for obtaining a feedback control amount according the comparison result, and for controlling the amount of the bypass air passing through a bypass air amount control valve 24. The control unit 10 stores the feedback control amount in the nonvolatile memory 11 only in the case the absolute value of the difference between the feedback control amount and a feedback control amount already stored in a nonvolatile memory 11 is the same as or larger than a predetermined value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine control device, and in particular, in a vehicle that cannot use a backup RAM, such as a vehicle that uses a small capacity battery such as a two-wheeled vehicle or a vehicle that does not use a battery, an air amount change occurs when the throttle valve is fully closed. Further, the present invention relates to an engine control device that can maintain the idle rotation speed.

  Conventionally, during idle operation, the actual rotational speed is compared with a predetermined target rotational speed, and the bypass air amount in the bypass air passage that bypasses the throttle valve provided in the intake passage of the engine is adjusted according to the comparison result. The idle air speed is controlled by feedback control of the bypass air amount control valve. Also, it is assumed that the amount of air when the throttle valve is fully closed changes due to aging (the amount of leakage air when the throttle valve is fully closed due to dust or carbon in the atmosphere (change due to clogging)). A method has been proposed in which, even when the air amount when the throttle valve is fully closed changes, the change in the air amount when the throttle valve is fully closed is learned from the feedback control amount and stored in the backup RAM (for example, , See Patent Document 1).

Japanese Patent No. 3239200

  However, since there are vehicles that cannot use a backup RAM, such as a vehicle that uses a small-capacity battery such as a two-wheeled vehicle, or a vehicle that does not use a battery, the conventional method for learning change in air amount as described above is used in such a vehicle. Then, since the learned air amount change cannot be stored in the backup RAM, it is necessary to write the learned air amount change into the nonvolatile memory. However, there is an upper limit on the number of rewrites in the nonvolatile memory, and if the storage process is performed every time an air amount change is learned, the upper limit on the number of rewrites in the nonvolatile memory may be exceeded. If the number of times the nonvolatile memory is rewritten exceeds the upper limit, the learned air amount change cannot be stored, and the idle speed cannot be controlled (the actual engine speed may increase or decrease). there were.

  In addition, when the nonvolatile memory is rewritten, the load factor of the microcomputer (for example, the load on the CPU) increases. Therefore, when the actual rotational speed of the engine is high, the load also increases, resulting in a delay in control and the engine. There was a problem that there was a risk of causing a malfunction.

  The present invention has been made to solve such a problem, and when storing the learned air amount change (feedback control amount) in the nonvolatile memory so as not to exceed the upper limit of the number of times of rewriting of the nonvolatile memory. The purpose of the present invention is to obtain an engine control device for reducing the number of rewrites of the nonvolatile memory by providing a limit, suppressing the number of rewrites of the nonvolatile memory from exceeding the upper limit, and maintaining the idle rotation speed. It is said.

  The present invention detects the operating state of the engine including a bypass air amount control valve for adjusting a bypass air amount of a bypass air passage provided in an intake passage of the engine by bypassing the throttle valve, and an actual rotational speed of the engine And a control means for providing a drive signal to the bypass air amount control valve according to the operating state obtained by the sensor means, and for controlling the opening and closing of the bypass air amount control valve, Feedback control mode determining means for determining whether or not a predetermined feedback control condition set in advance is satisfied based on the operating state obtained by the sensor means, and when the feedback control condition is satisfied, The actual rotation speed is compared with a predetermined target rotation speed set in advance, and a feedback control amount is determined according to the comparison result. In order to store the feedback control amount learning means for controlling the amount of bypass air passing through the bypass air amount control valve, the initial value of the feedback control amount and the feedback control amount obtained by the feedback control amount learning means A non-volatile memory, and a storage determination unit that determines whether or not to store the feedback control amount in the non-volatile memory, wherein the storage determination unit is a feedback control amount obtained by the feedback control amount learning unit. And the absolute value of the difference between the feedback control amount already stored in the non-volatile memory and whether or not the absolute value of the difference is equal to or greater than a predetermined value is determined. The feedback control amount obtained by the feedback control amount learning means An engine control device stored in the.

  The present invention detects the operating state of the engine including a bypass air amount control valve for adjusting a bypass air amount of a bypass air passage provided in an intake passage of the engine by bypassing the throttle valve, and an actual rotational speed of the engine And a control means for providing a drive signal to the bypass air amount control valve according to the operating state obtained by the sensor means, and for controlling the opening and closing of the bypass air amount control valve, Feedback control mode determining means for determining whether or not a predetermined feedback control condition set in advance is satisfied based on the operating state obtained by the sensor means, and when the feedback control condition is satisfied, The actual rotation speed is compared with a predetermined target rotation speed set in advance, and a feedback control amount is determined according to the comparison result. In order to store the feedback control amount learning means for controlling the amount of bypass air passing through the bypass air amount control valve, the initial value of the feedback control amount and the feedback control amount obtained by the feedback control amount learning means A non-volatile memory, and a storage determination unit that determines whether or not to store the feedback control amount in the non-volatile memory, wherein the storage determination unit is a feedback control amount obtained by the feedback control amount learning unit. And the absolute value of the difference between the feedback control amount already stored in the non-volatile memory and whether or not the absolute value of the difference is equal to or greater than a predetermined value is determined. The feedback control amount obtained by the feedback control amount learning means Since the engine control device stores the amount of air change (feedback control amount) learned in the non-volatile memory so as not to exceed the upper limit of the number of rewrites of the non-volatile memory, the non-volatile memory The number of rewrites of the volatile memory can be reduced so that the number of rewrites of the non-volatile memory does not exceed the upper limit, and the idle rotation speed can be maintained.

Embodiment 1.
An engine control apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a configuration diagram showing a state where an engine control apparatus according to Embodiment 1 of the present invention is attached to an engine.

  As shown in FIG. 1, the engine control apparatus according to Embodiment 1 of the present invention is provided with a control unit 10 that constitutes a main part of the engine control apparatus. The control unit 10 includes a microcomputer having a CPU, a ROM, a RAM, an I / O interface, and the like, and stores a program and a map for controlling the overall operation of the engine 25. Further, the control unit 10 includes a nonvolatile memory 11. The nonvolatile memory 11 stores in advance an initial value Qeep of the feedback control amount Qfb with respect to the bypass air amount in the bypass air passage, and also stores a feedback control amount Qfb (updated value) obtained by learning.

  An intake passage 22 for introducing intake air into the engine 25 has an air cleaner 21 that removes foreign matters in the air to generate intake air to the engine 25, an intake air temperature sensor 1 that measures the temperature of intake air, and a bypass. A throttle valve 23 that is opened and closed by an air amount control valve 24 (throttle actuator), a bypass air passage provided so as to bypass the throttle valve 23, and a bypass air amount control valve that adjusts the bypass air amount of the bypass air passage 24, a throttle position sensor 2 for measuring the opening TH of the throttle valve 23, an intake pressure sensor 3 for measuring the intake air pressure downstream of the throttle valve 23, and fuel stored in the fuel tank 26 is injected into the engine 25. And a fuel injection module 27 is provided.

  Further, the engine 25 measures the engine temperature sensor 4 that measures the wall surface temperature WT of the engine 25 (hereinafter referred to as the temperature WT of the engine 25), the rotational speed Ne of the engine 25, and the crank position of the engine 25. A crank angle sensor 5 that outputs a crank angle signal (pulse) corresponding to the crank position and an ignition plug 29 driven by an ignition coil 28 are provided.

  Further, in the exhaust passage 30 for exhausting exhaust gas from the engine 25, an oxygen concentration sensor 6 (air-fuel ratio sensor) for detecting the oxygen concentration in the exhaust gas and NOx, HC and CO contained in the exhaust gas are removed. An exhaust gas purification catalyst 31 (three-way catalyst) for purifying the exhaust gas is provided.

  Next, the operation of the engine control apparatus according to the first embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing an initial operation of control unit 10 of the engine control apparatus according to Embodiment 1 of the present invention. FIG. 3 is a flowchart showing the bypass air amount setting operation of the control unit 10. Further, FIG. 4 is a flowchart showing the feedback control amount setting operation of FIG. FIG. 5 is a flowchart showing the feedback control amount storage processing operation of the control unit 10.

  The control unit 10 calculates a bypass air amount for controlling the idle rotation speed according to the routines shown in FIGS. 2 to 5, and outputs a drive signal Q to the bypass air amount control valve 24.

  Further, the control unit 10 uses the intake air temperature detected by the intake temperature sensor 1, the throttle valve opening TH detected by the throttle position sensor 2, the intake air pressure detected by the intake pressure sensor 3, and the engine temperature sensor 4. It includes at least one or more of the detected temperature WT of the engine 25, the actual rotational speed Ne (or crank position) of the engine 25 detected by the crank angle sensor 5, and the oxygen concentration detected by the oxygen concentration sensor 6. Based on information relating to the driving state of the vehicle, an appropriate fuel injection timing and fuel injection amount are calculated, and a drive signal corresponding to them is output to the fuel injection module 27.

  Similarly, the control unit 10 calculates an appropriate ignition timing and energization time based on information related to the driving state of at least one of the detection values from the various sensors 1 to 6 and responds to them. The drive signal to be output is output to the ignition coil 28.

  First, the initial operation of the control unit 10 of the engine control device will be described with reference to FIG.

  In step S101, the control unit 10 reads the value Qeep stored in the nonvolatile memory 11 as an initial value and sets it as the feedback control amount Qfb when the power is turned on.

  Next, the bypass air amount setting operation of the control unit 10 of the engine control device will be described with reference to FIG.

  In step S201, the control unit 10 calculates a basic air amount Qi based on the temperature WT of the engine 25 detected by the engine temperature sensor 4 using the map TQBASE (WT). That is, the map TQBASE (WT) stores the basic air amount TQBASE (WT) corresponding to the temperature WT for each temperature WT of the engine 25. Accordingly, the basic air amount Qi with respect to the detected temperature WT of the engine 25 is read from the map TQBASE (WT), and the basic air amount Qi is set so that Qi = TQBASE (WT).

  Next, in step S202, the control unit 10 sets a feedback control amount Qfb. Details of the method of setting the feedback control amount Qfb will be described later with reference to FIG.

  Next, in step S203, the control unit 10 calculates the bypass air amount Q based on the basic air amount Qi set in step S201 and the feedback control amount Qfb set in step S202. That is, the bypass air amount Q is set based on the arithmetic expression Q = Qi + Qfb. The control unit 10 outputs a drive signal corresponding to the calculated bypass air amount Q to the bypass air amount control valve 24.

  The control unit 10 repeats the above-described bypass air amount setting operation (steps S201 to S203) every predetermined time or every predetermined rotation of the engine 25 after the power is turned on.

  Here, the feedback control amount setting operation of the control unit 10 of the engine control apparatus will be described with reference to FIG.

  In step S301, the control unit 10 determines whether or not a feedback control condition (feedback control mode) is established based on the actual rotational speed Ne of the engine 25, the temperature WT of the engine 25, and the throttle valve opening TH. To do. The feedback control condition (feedback control mode) is, for example, that the control unit 10 determines that the actual rotational speed Ne of the engine 25 is within a predetermined range, the temperature WT of the engine 25 is within a predetermined range, and the throttle valve When the opening degree TH is within a predetermined range, it is determined that it is established. When the feedback control condition (feedback control mode) is established, the process proceeds to the next step S302. On the other hand, when the feedback control condition (feedback control mode) is not satisfied, the feedback control is not performed, and the process proceeds to RETURN.

  In step S302, the control unit 10 calculates the target rotational speed Ns based on the temperature WT of the engine 25 detected by the engine temperature sensor 4 using the map TNTRGT (WT). That is, for each temperature WT of the engine 25, the target rotational speed TNTRGT (WT) corresponding to the temperature WT is stored in the map TNTRGT (WT). Therefore, the target rotational speed Ns for the detected temperature WT of the engine 25 is read from the map TNTRGT (WT), and the target rotational speed Ns is set so that Ns = TNTRGT (WT).

  In step S303, the control unit 10 compares the actual rotational speed Ne of the engine 25 with the target rotational speed Ns. If Ne <Ns, the control unit 10 proceeds to step S304. On the other hand, if Ne> Ns, the process proceeds to step S305. If Ne = Ns, the process proceeds to return.

  In step S304, the control unit 10 adds a predetermined value Qd set in advance to the feedback control amount Qfb, obtains the learned feedback control amount Qfb, and proceeds to return.

  In step S305, the control unit 10 subtracts a predetermined value Qd set in advance from the feedback control amount Qfb to obtain the learned feedback control amount Qfb, and proceeds to return.

  Next, the feedback control amount storage processing operation of the control unit 10 of the engine control device will be described with reference to FIG.

  In step S401, the control unit 10 determines whether or not a feedback control amount storage condition (feedback control amount storage mode) is satisfied. The feedback control amount storage condition (feedback control amount storage mode) is that the actual rotational speed Ne of the engine 25 is within a predetermined range (for example, within a range from 1250 rpm to 2000 rpm), and the throttle valve opening TH is a predetermined value. It is determined that the condition is satisfied when the condition of (for example, 3.0 deg) or less is satisfied. When the feedback control amount storage condition (feedback control amount storage mode) is established, the process proceeds to the next step S402. On the other hand, when the feedback control amount storage condition (feedback control amount storage mode) is not satisfied, the feedback control amount is not stored in the nonvolatile memory 11, and the process proceeds to return.

  Next, in step S402, the control unit 10 determines whether or not to store the feedback control amount Qfb calculated in step S304 or step S305 in the nonvolatile memory 11. In other words, the control unit 10 stores in the nonvolatile memory 11 when the absolute value of the difference between the calculated feedback control amount Qfb and the value Qeep stored in the nonvolatile raw memory 11 is equal to or greater than a predetermined value (for example, duty 5%). Judge that. That is, when | Qfb−Qeep | ≧ predetermined value, it is determined to store in the nonvolatile memory 11. Therefore, if | Qfb-Qeep | ≧ predetermined value, the process proceeds to step S403. On the other hand, if | Qfb-Qeep | <predetermined value, the data is not stored in the non-volatile memory 11, and the process proceeds to return.

  In step S403, the control unit 10 stores the calculated feedback control amount Qfb in the nonvolatile memory 11, and proceeds to return.

  The control unit 10 repeats the above-described feedback control amount storage processing operation (steps S401 to S403) every predetermined time or every predetermined rotation of the engine 25 after the power is turned on.

  As described above, the engine control apparatus according to the first embodiment of the present invention compares the actual rotation speed with a predetermined target rotation speed, and passes through the bypass air amount control valve 24 according to the comparison result. This is an engine control device that controls the idle rotation speed by feedback-controlling the bypass air amount, and has a configuration in which the learned change in the bypass air amount (feedback control amount) is written in the nonvolatile memory 11. In the first embodiment, in order to reduce the number of times the nonvolatile memory 11 is rewritten, the feedback control amount (the amount of change in the learned bypass air amount) is stored in the nonvolatile memory 11 as shown in step S402 in FIG. There is now a restriction to determine whether or not to do so. That is, the learned feedback control amount is stored in the nonvolatile memory 11 only when the absolute value of the difference between the learned feedback control amount and the feedback control amount already stored in the nonvolatile memory 11 is equal to or larger than a predetermined value set in advance. I remembered it. As a result, the number of rewrites of the nonvolatile memory 11 can be reduced, the upper limit of the number of rewrites of the nonvolatile memory 11 can be prevented, and the idle rotation speed can be maintained.

  Further, only when a limit regarding the actual rotational speed Ne and the throttle valve opening TH of the engine 25 is provided and satisfied, as shown in step S401, in the preceding stage of the determination in step S402 in FIG. Since the determination in step S402 is performed, the load factor of the microcomputer (for example, the load on the CPU) can be reduced, and consequently, engine malfunction due to a delay in control can be prevented.

  The engine control device of the present invention is particularly effective in a vehicle that cannot use a backup RAM, such as a vehicle that uses a small-capacity battery such as a two-wheeled vehicle or a vehicle that does not use a battery, but can also be applied to various other vehicles. Needless to say.

It is a figure which shows the structure of the engine control apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the initial stage operation | movement of the control unit of the engine control apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the bypass air amount setting operation | movement of the control unit of the engine control apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the feedback control amount setting operation | movement of FIG. It is a flowchart which shows the feedback control amount memory | storage process operation | movement of the control unit of the engine control apparatus which concerns on Embodiment 1 of this invention.

Explanation of symbols

  1 intake temperature sensor, 2 throttle position sensor, 3 intake pressure sensor, 4 engine temperature sensor, 5 crank angle sensor, 6 oxygen concentration sensor, 10 control unit, 11 nonvolatile memory, 21 air cleaner, 22 intake passage, 23 throttle valve, 24 bypass air amount control valve, 25 engine, 26 fuel tank, 27 fuel injection module, 28 ignition coil, 29 spark plug, 30 exhaust passage, 31 exhaust gas purification catalyst.

Claims (2)

A bypass air amount control valve that bypasses the throttle valve and adjusts the bypass air amount of the bypass air passage provided in the intake passage of the engine;
Sensor means for detecting an operating state of the engine including an actual rotational speed of the engine;
Control means for giving a drive signal to the bypass air amount control valve according to the operating state obtained by the sensor means, and for controlling the opening and closing of the bypass air amount control valve;
Feedback control mode determination means for determining whether or not a predetermined feedback control condition set in advance is satisfied based on the operation state obtained by the sensor means;
When the feedback control condition is satisfied, the actual rotation speed is compared with a predetermined target rotation speed set in advance, a feedback control amount is obtained according to the comparison result, and the bypass air amount control valve Feedback control amount learning means for controlling the amount of bypass air passing through
A non-volatile memory for storing an initial value of the feedback control amount and the feedback control amount obtained by the feedback control amount learning means;
Storage determination means for determining whether or not to store the feedback control amount in the nonvolatile memory,
The storage determination unit obtains an absolute value of a difference between the feedback control amount obtained by the feedback control amount learning unit and the feedback control amount already stored in the nonvolatile memory, and the absolute value of the difference is calculated in advance. It is determined whether or not the set predetermined value or more, and when it is the predetermined value or more, the feedback control amount obtained by the feedback control amount learning means is stored in the nonvolatile memory. .   The memory judging means is further said that, as a preceding stage of the judgment, the actual rotational speed of the engine is within a predetermined range set in advance and the opening degree of the throttle valve is equal to or less than a preset predetermined value. The engine control apparatus according to claim 1, wherein it is determined whether or not a condition is satisfied.

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