JP2008267239A - Engine speed control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To meet a requirement of measuring in a reference operational state for acquiring a torque step at each cylinder by defining the reference operational state to reduce causes for generating rotation fluctuation, when a correction amount corresponding to the torque step from the rotation fluctuation by measuring the rotation fluctuation corresponding to the torque generated in each cylinder. <P>SOLUTION: In a control device for controlling a speed of an engine, the engine speed is measured to calculate a parameter indicating fluctuation in engine speed, and a fuel injection amount supplied to each cylinder of the engine is controlled according to the parameter, thus suppressing the fluctuation in engine speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to control of the fuel injection amount of an engine, and more particularly to a technique for reducing the HC component contained in the exhaust gas of the engine by reducing the combustion air-fuel ratio while suppressing fluctuations in the rotational speed.

  The amount of fuel required at the time of starting the engine is increased by increasing the fuel injection amount at the time of lowering the temperature, considering the vaporization rate corresponding to the temperature of the intake pipe. Since the fuel vaporization rate depends not only on the temperature but also on the volatile components contained in the fuel, light fuel containing many components that are easily vaporized and heavy fuel containing relatively few volatile components are used in the market. Such differences in fuel volatility appear as differences in fuel properties. Especially in the overseas market, the fuel property difference in the market is large, so the start-up fuel that matches the worst heavy fuel in the market is set and the startability is secured, so when the fuel is light fuel The combustion air-fuel ratio becomes rich and a lot of HC components are discharged.

  Further, due to manufacturing variations of injectors for injecting fuel and pressure variations of the fuel pressure regulator, even if a predetermined fuel injection pulse is applied to the injector, the fuel actually injected into the intake pipe varies from engine to engine. For this reason, it is necessary to set a larger fuel injection pulse width in consideration of the lower limit value of the variation in the fuel injection amount. This additional correction amount causes the combustion air-fuel ratio to become rich in an engine that is at the upper limit of the variation in the fuel injection amount, so that a large amount of HC component is also discharged.

  In addition, as a variation in the parts that make up the engine, an increase correction is made to ensure startability even in the worst case, taking into account the distribution variation from cylinder to surge tank to the intake pipe and the variation in compression ratio for each cylinder. Including the increase in the amount after starting.

  For this reason, in the cylinder in which the lower limit value of the injector variation and the air distribution variation for each cylinder are maximized and the air-fuel ratio is lean, the generated torque is reduced, and therefore, rotation fluctuation is likely to occur. There is a problem that the air-fuel ratio is further enriched in order to suppress rotational fluctuation.

JP 2006-104985 A

  In the present invention, by measuring the rotational fluctuation corresponding to the generated torque for each cylinder, a correction amount corresponding to the torque step is obtained for each cylinder from the rotational fluctuation.

  In this case, in order to obtain the torque step for each cylinder, it is necessary to perform measurement under the reference operating condition, and it becomes a problem to define the reference operating condition and reduce the factors that cause rotation fluctuation.

  Further, in the present invention, the rotational fluctuation corresponding to the torque generated for each cylinder is measured to convert the rotational fluctuation into a parameter corresponding to the torque, and the shortage of the torque is reflected in the fuel amount.

  When feedback control is performed using a correction increase that corrects the fuel amount so as to suppress rotational fluctuations, there is a problem that the correction increase becomes excessive and the exhaust level deteriorates.

  In the present invention, the rotational fluctuation is converted into a parameter corresponding to the torque by measuring the rotational fluctuation corresponding to the torque generated for each cylinder. Since the generated torque affects not only the amount of fuel but also the ignition timing, there is a problem that control is performed in consideration of the influence of the ignition timing when the rotational fluctuation is converted into a parameter corresponding to the torque.

  Further, in the present invention, the rotational fluctuation is converted into a parameter corresponding to the torque by measuring the rotational fluctuation corresponding to the generated torque generated for each cylinder. Therefore, an angular width capable of specifying the torque detection for each cylinder is set. It is necessary to measure the transit time. In this case, the misfire detection angle may be different, and a plurality of angle settings must be prepared. However, there are limitations on the number of input terminals of the CPU and the CPU processing capacity required for interrupt processing for measuring the passing time. Therefore, there is a problem that the factors causing the interruption are made common so that processing can be performed within the limits of the number of terminals and the CPU processing capacity.

  A means for determining whether the operating condition for detecting the rotational speed fluctuation parameter is prepared is provided, and when the operating condition is satisfied, the rotational fluctuation is measured to detect the rotational fluctuation parameter, and the correction corresponding to the torque step. The amount is calculated.

  Further, a limit value is provided for the fuel correction increase amount so that the fuel correction increase amount does not become excessive. The limit value is a difference between the upper and lower limit values of the increase value according to the volatility of the fuel used.

  A time average value of the ignition timing is obtained, and a fuel correction increase amount is calculated according to the time average value of the ignition timing.

  In addition, the interruption of the crank angle sensor signal generated at every predetermined angle is set as a common angle, and the time passing through the common angle is integrated for each angle interruption to measure the passing time of a plurality of angular widths.

  According to the present invention, since the HC component in the exhaust gas can be suppressed regardless of the fuel property while ensuring the startability, the exhaust reduction effect is high.

  Examples according to the present invention will be described below.

  FIG. 1 shows an engine configuration in the present invention.

  In the internal combustion engine 1, a fuel injection valve 7 and a spark plug 8 are disposed in a cylinder 1a, fuel is injected from the fuel injection valve into the intake manifold 6 at a predetermined crank angle, and air and fuel are mixed. The air is sucked into the combustion chamber from the intake valve.

  A high voltage is applied to the spark plug at an appropriate crank angle, and a spark discharges into the cylinder and explodes and burns due to the high voltage discharge.

  The crank angle is detected by the crank angle sensor 14, and at the same time, the engine speed is calculated according to the time interval of the pulses of the crank angle sensor or the number of pulses generated within a predetermined time. Further, cylinder discrimination is performed using a cam angle sensor indicating a specific position of the crank angle. The water temperature sensor 13 and the exhaust sensor 12 correct the fuel amount and the air amount, and the exhaust gas is purified through the catalyst 11.

  Control of intake air to the cylinder and exhaust to the exhaust pipe are performed by an intake valve control device and an exhaust valve control device, respectively. The valve opening timing and the valve closing timing are controlled by the intake valve control device or the exhaust valve control device in accordance with the crank angle. Also, the lift amount of the intake valve is controlled simultaneously.

  On the intake side of the internal combustion engine, an air cleaner 9, an air flow meter 2 that measures the amount of intake air, or a pressure sensor that measures the pressure in the intake pipe and an intake temperature sensor are installed as required depending on the system configuration.

  Furthermore, in order to detect a driver | operator's acceleration request value, the structure which uses the accelerator pedal sensor which detects the depression amount of an accelerator pedal is also possible. Between the accelerator pedal and the throttle 3, a mechanical throttle linked by a wire or an electronically controlled throttle for controlling a throttle opening by transmitting a signal in accordance with an accelerator pedal sensor output is provided.

  The electronically controlled throttle adjusts the amount of air flowing into the cylinder of the internal combustion engine, and the electronically controlled throttle opening is controlled based on the operation amount of the accelerator pedal of the driver and the engine control amount. The electronic control throttle includes a throttle valve, a motor that rotates the throttle valve, and a throttle opening sensor that detects the throttle opening. The target throttle opening is calculated in the engine control device in accordance with the driver's accelerator pedal depression amount and engine control amount. The target throttle opening is transmitted from the engine control device to the electronic control throttle control device, and the electronic control throttle control device controls the angle detected by the throttle opening sensor 16 to be the target throttle opening.

  Also install a gear ratio or gear position sensor for the transmission. When the transmission is an AT gear, information on whether the gear position is in the parking or neutral position or any other position is also output.

  In order to detect the driving state of the vehicle, a vehicle speed sensor that detects the number of rotations of the wheel, a steering sensor that detects the operation angle of the steering wheel, a brake sensor that detects the operation amount of the brake pedal, and the vehicle speed and brake pressure for each wheel. A vehicle body control device, an outside air temperature sensor, etc. are installed.

  FIG. 2 shows an example of the engine control device.

  The engine control device includes an intake air amount detection signal by an air flow sensor that detects the amount of air taken into the engine, an accelerator pedal sensor signal, an intake pipe pressure sensor, a water temperature sensor, an outside air temperature sensor, a battery voltage, and an engine speed. A crank angle sensor for detecting the crank angle, a cam angle sensor for determining the cylinder, a vehicle speed sensor for measuring the rotation speed of the wheel, an electric load switch for detecting the application state of a brake pedal switch and other electric loads, a transmission Input gear ratio information or gear position information.

  Engine control device output includes fuel injection valve open / close control output, ignition signal output, electronic throttle target opening output, electric turbocharger target speed output, electric supercharger bypass valve control output , Etc. are output.

  Furthermore, a communication means is provided in the engine control device for monitoring each input signal and output signal diagnosis result and internal data.

  The engine control device includes an input unit, a calculation unit, an output unit, and a communication unit. The input unit includes an A / D conversion circuit, a pulse input circuit, a switch input circuit, and the like. The calculation unit includes a calculation device CPU, ROM, RAM, an external storage unit (EEPROM), and a time measurement unit. The output unit includes a pulse output circuit, a relay output circuit, and the like. The communication unit includes an input / output circuit that performs level conversion and timing conversion of a communication signal.

  FIG. 3 shows the internal configuration of the engine control apparatus.

  First, the elapsed time of the crank angle related to engine combustion is measured. As measurement, the following processing is performed.

  Elapsed time from when the cam angle sensor output pulse is generated until the counter value reaches the predetermined value by counting the crank angle sensor output pulse so as to include the expansion stroke of the engine starting from the predetermined delay angle Calculate time.

  Even if the processing error and mounting error of the plate for detecting the crank angle and the manufacturing error of the engine crank overlap, even if the engine rotates at a constant rotation speed, an error occurs in the elapsed time.

  Therefore, the elapsed time between predetermined crank angles is measured while the engine is cutting fuel, and a crank angle detection error including a machining error of a plate for detecting the crank angle and a crank manufacturing error is calculated for each cylinder.

  When the engine is running in a steady state, the number of explosions is counted for each explosion and the elapsed time between predetermined crank angles is measured. Each time the elapsed time is measured, the elapsed time is corrected by multiplying the elapsed time by the crank angle detection error for each cylinder, and the corrected elapsed time for each cylinder is defined as D_TIME.

  The difference from the elapsed time D_TIMEz before one explosion is calculated to obtain a primary differential value DD_TIME.

DD_TIME = D_TIME-D_TIMEz
D_TIMEz = D_TIME
Further, a difference between the primary differential value DD_TIME and the primary differential value DD_TIMEz before the first explosion is calculated to obtain DDD_TIME.

DDD_TIME = DD_TIME-DD_TIMEz
DD_TIMEz = DD_TIME
The primary differential value and the secondary differential value are each compared with a threshold value, and a flag indicating that rotational fluctuation has occurred when the threshold value is exceeded is set.

  As shown in FIG. 4, the threshold value is set by parameters such as water temperature, elapsed time after engine start, number of ignition after start, ignition timing, and the like. Since the rotational speed correction by the ignition timing is performed to maintain the idle rotational speed, the instantaneous ignition timing for each cylinder is not constant. Therefore, a time average value or a weighted average value of the ignition timing is obtained and set as the average value of the ignition timing, and the threshold value is corrected according to the average value of the ignition timing.

Let P_DD be the difference between the primary differential value and the threshold when the rotational fluctuation occurs, and combine the previous two differences,
P_DD [0], P_DD [1], P_DD [2]
And

And, the difference between the secondary differential value and the threshold value when the rotation fluctuation occurs is set as P_DDD, and the past two differences are combined,
P_DDD [0], P_DDD [1], P_DDD [2]
And

  The past two times are added to obtain the magnitude of the rotational fluctuation.

That is,
P_DDALL = P_DD [0] + P_DD [1] + P_DD [2]
P_DDDALL = P_DDD [0] + P_DDD [1] + P_DDD [2]
Then, based on the magnitude of the rotational fluctuation, the corrected increase value retrieved from the preset table value is obtained. The larger one of the corrected increase value of the primary differential value and the corrected increase value of the secondary differential value is selected and added to the past correction amount.

  Since the rotation fluctuation detection is always performed, the amount can be increased until the rotation fluctuation does not occur, and the effect of suppressing the rotation fluctuation after starting the engine is high.

The upper limit of the correction value is the difference HOSAH between the maximum post-start increase value KASBS when heavy gasoline is used and the post-start increase value KASRB when light gasoline is used, and when the difference HOSAH is negative (heavy The difference HOSAH is set to 0 in the after-start increase value KASBS for gasoline <light-start increase value KASRB for light gasoline). With this operation, even if the rotation fluctuation is detected and the correction increase value becomes large, an excessive correction amount is not added to the fuel injection amount. Further, since the difference between the plurality of post-start-up increase values is taken, it is not necessary to adapt the setting of the corrected increase value, and there is an effect that the adaptation can be simplified.

  As shown in FIG. 5, the post-start-up increase value changes according to the post-start-up time.

  The difference between the after-start increase value for light gasoline (KASRB) and the after-start increase value for heavy gasoline (KASBS) is used as the upper limit value HOSAH of the correction amount.

  FIG. 6 shows an operation example of the correction method.

  If the rotational fluctuation is not more than the threshold value, the fuel increase is gradually attenuated according to the difference between the rotational speed and the target rotational speed of the ISC control, and the fuel increase is performed immediately after the rotational fluctuation is detected.

  That is, when the primary differential value DD_TIME or the secondary differential value DDD_TIME exceeds a threshold value, a fuel increase flag is set.

  Based on the difference P_DD between the primary differential value DD_TIME and the threshold value, or the difference P_DDD between the secondary differential value DDD_TIME and the threshold value, a fuel increase correction amount is searched from a preset table value, and fuel is increased to the fuel increase amount. Add the increase correction amount.

  If the rotational fluctuation is less than or equal to the threshold value, a predetermined step amount is subtracted until the fuel increase becomes zero.

  The engine is started at the fuel injection amount when heavy gasoline is used in consideration of startability. Thereafter, after the rotational speed is increased and exceeds the target rotational speed of ISC control, correction is permitted after a predetermined number of explosions.

  The correction process is executed in a state where the elapsed time passing through a predetermined crank angle including the expansion stroke and the crank angle detection error corresponding to the corresponding cylinder are fixed.

  Furthermore, since it is contrary to air-fuel ratio control, it is necessary that air-fuel ratio control is not performed.

  Moreover, since it is a premise that the engine is in an idle state after the engine is started, it is necessary that the accelerator petal is in the fully closed position. For this reason, it is also necessary that a flag indicating that the accelerator pedal is learned to be in the fully closed position is set.

  It is necessary that the battery voltage is within a predetermined voltage range and the water temperature is within a predetermined value.

  The gear position of the transmission needs to be nowhere, and in the case of AT, it must be in the parking or neutral position.

  In addition, it is confirmed that the vehicle speed is zero as the vehicle is in a stopped state.

  FIG. 7 shows a flowchart.

  Counting by the crank angle sensor, the following processing is performed by an interrupt measuring the crank angle passage time when the predetermined crank angle is reached.

  First, the detection permission condition is checked.

Air-fuel ratio control is not performed. Accelerator pedal fully closed position learning is completed. Crank angle error detection is confirmed. Water temperature is within the specified range. The engine speed is the target of ISC control. The number of explosions has exceeded the number of rotations after that. The gear position of the transmission is not entered anywhere, or in the case of AT, it is a parking or neutral position. The vehicle speed is zero. Battery Detection is permitted when the voltage is within a predetermined range or the like.

  If detection is permitted, the following calculation is performed.

  When starting the engine, select an increase value for light gasoline after starting.

  Next, the crank angle passage time is captured. At the same time, the explosion counter is incremented.

  Next, the crank angle detection error data of the corresponding cylinder is retrieved and corrected by multiplying the crank angle passage time.

  Further, a difference between the corrected crank angle passage time and the passage time at the previous interruption is calculated to obtain a primary differential value DD_TIME. A difference from the previous primary differential value is obtained to obtain a secondary differential value DDD_TIME.

  When the rotation fluctuation detection flag is set, the fuel increase is calculated as follows by the correction method.

  When the primary differential value exceeds the threshold value or when the secondary differential value exceeds the threshold value, the difference between the primary differential value and the threshold value or the difference between the secondary differential value and the threshold value is set. Based on the table value set in advance, the fuel increase correction amount is retrieved and added to the fuel increase so far.

  When the rotation fluctuation detection flag is reset, the fuel increase is attenuated by a predetermined step amount until zero after the predetermined number of explosions.

  The following operations are performed when the above-described rotation variation detection permission is reset.

When air-fuel ratio control has started Accelerator pedal fully closed position learning has not been completed Crank angle error detection has not been confirmed When the water temperature has risen and deviated from the specified range After the start, the number of explosions has reached the specified number When the gear position of the transmission is no longer neutral When the vehicle speed is other than zero When the battery voltage falls outside the specified range In particular, after assembling in the car manufacturer's production line or after removing the battery in the market Immediately after being performed, the check whether the accelerator pedal is in the fully closed position is incomplete. Further, crank angle error detection is not determined unless fuel cut is performed.

  Therefore, if learning of the fully closed position of the accelerator pedal is not completed, or if crank angle error detection is not confirmed, the fuel increase is kept at zero and the fuel injection amount corresponding to heavy gasoline is selected. To do.

  If learning of the fully closed position of the accelerator pedal is completed and the detection of the crank angle error is confirmed, the increase control is performed immediately after the engine speed exceeds the target engine speed of ISC control. When the lambda control is started, the correction amount corresponding to the fuel increase at that time is transferred to the initial value of the air-fuel ratio control to suppress the air-fuel ratio fluctuation due to the increase. Alternatively, the air fuel ratio control can be prevented from being affected by gradually returning the fuel increase amount to zero. FIG. 8 shows the operation for starting the air-fuel ratio control.

  When the water temperature rises or the number of explosions exceeds a predetermined number, the fuel increase is gradually returned to zero.

  When the gear position of the transmission is no longer neutral or when the vehicle speed is other than zero, the fuel increase is immediately returned to zero.

  Even when the battery voltage is outside the predetermined range, the increase is immediately returned to zero.

  Also, when the start-up speed is slow and does not reach the target speed for idle control within a predetermined time or a predetermined number of explosions, the post-start increase is switched to heavy gasoline. Then, the increase correction by the post-startup control is set to zero.

  If the torque generated for each cylinder of the engine is constant, only the torque fluctuation corresponding to the fluctuation of the air-fuel ratio appears as the rotation fluctuation, so that the rotation fluctuation parameter for the air-fuel ratio can be obtained as shown in FIG. .

  However, since the air-fuel ratio of each cylinder shifts due to the injector flow rate variation and the air distribution error for each cylinder, a characteristic having a predetermined width actually appears in the characteristic diagram shown in FIG.

Therefore, under the condition that the air-fuel ratio becomes constant by O ₂ control, if the rotational fluctuation is detected and periodic rotational fluctuation occurs for each cylinder, the fuel amount is corrected for a specific cylinder, Variation can be suppressed.

  As shown in FIG. 11, in the state where the rotational speed is gradually increasing or decreasing, the first-order differential value is affected by the rotational fluctuation. In addition, since the first-order differential value is affected by the rotational fluctuation of the adjacent cylinders, an operation for removing the rotational fluctuation while the engine rotates twice is performed.

  For example, the D1A parameter is obtained by the following arithmetic expression.

D1A = (− DTIME1 + DTIME4−DTIME5 × 3) / 4
DTIME1 = Rotational fluctuation before 1 time DTIME4 = Rotational fluctuation before 4 times DTIME5 = Rotational fluctuation before 5 times, D1A parameters are calculated for each cylinder.

Further, in order to limit the operating state in which the rotational fluctuation occurs, the water temperature is within a predetermined range, the O ₂ control is performed, the integrated value of the intake air amount or the integrated value of the fuel injection amount is within the predetermined range, The following correction amount calculation is performed when the condition is satisfied, such as the neutral state of the machine, the state where no auxiliary load such as an electric load or an air conditioner is included, and the like.

First, the number of times that the O ₂ control changes from the rich state to the lean state, or from the lean state to the rich state is counted, and the calculation is initialized during the transition several times (about twice).

  Values used for the calculation are as follows, and a flowchart is shown in FIG.

DICH partial integration during rich period (by cylinder) IRICHn
D1A partial calculation count counter (by cylinder) CRICHn during rich period
DEAN partial integration during lean period (by cylinder) ILEANn
D1A partial calculation counter during lean period (by cylinder) CLEANn
Total D1A total over rich period (by cylinder) TTLRICHn
D1A total accumulated number counter for each rich period (by cylinder) TTLCRICHn
Total accumulated D1A over the entire lean period (by cylinder) TTLLEANNn
D1A total accumulated number counter for each lean period (by cylinder) TTLCLEANn
A rich state / lean state transition number counter (by cylinder) CRLSWCHn during the integration period, and the above value is reset to zero.

When the engine is in the rich state after two transitions have elapsed, D1A during the rich period is added to IRICHn for each cylinder. Further, every time integration is performed, the D1A partial calculation number counter CRICHn is incremented. When transitioning from the rich state to the lean state, when the D1A partial calculation number counter CRICHn is within the range of the upper and lower limit values (KRLSHORT to KRLLONG), the transition number counter CRLSWCHn is incremented. Further, the D1A partial integration IRICHn is added to the D1A total integration value TTLRICHn, and the D1A partial calculation count counter CRICHn is added to the D1A total integration count counter TTLCRICHn. When the lean state returns to the rich state, the D1A partial integration IRICHn and the D1A partial calculation number counter CRICHn are reset to zero.

  The same calculation is performed for the lean counter.

That is, after several transitions (about 2 times) have elapsed, when the engine is in the lean state, D1A during the lean period is integrated into ILEANn for each cylinder. Further, every time integration is performed, the D1A partial calculation number counter CLEANn is incremented. When a transition is made from the lean state to the rich state, the D1A partial calculation number counter CLEANn is set to an upper / lower limit value range (KRLSHORT ~
(KRLLONG), the transition number counter CRLSWCHn is incremented. Further, the D1A integral ILEANn is added to the D1A total integrated value TTLLLEANn,
The D1A partial calculation number counter CLEANn is added to the D1A total integration number counter TTLCLEANn. When the lean state returns to the rich state, the D1A partial integration ILEANn and the D1A partial calculation number counter CLEANn are reset to zero.

  When the rich state / lean state counter CRLSWCHn reaches a predetermined number of times of switching (about 10 times) in all the cylinders, the average value of the rotational fluctuation parameters for each cylinder is calculated.

That is, a value obtained by adding the D1A total integration TTLRICn during the rich period and the D1A total integration TTLLEAnn during the lean period is obtained.
TTLRLn = TTLRICn + TTLLEANn
At the same time, the addition value of the number counters CRICHn and CLEANn TTLCRLn = CRICHn + CLEANn
Is calculated.

Average value D1AAVEn = TTLRLn / TTLLCRLn
Based on the average value D1AAVEn, the correction step amount RBCYLADDn of the corresponding cylinder is calculated.

RBCYLADDn = table (D1AAVEn)
The correction step amount is added to the correction value CYLHOSnn, and the upper and lower limit limits are applied to finally obtain the cylinder specific correction amount CYLHOSn.

  FIG. 13 shows a timing chart.

  When the execution condition of this control is canceled, the cylinder specific correction amount CYLHOSn is gradually returned to zero.

  Although it is desirable that the time measurement window corresponding to the torque is shared with the misfire parameter, the misfire detection window setting position changes according to the rotational speed. Further, the optimal window position for misfire detection changes according to the misfire detection method.

The window position used in this control is generally the section that includes the expansion stroke.
90 degrees to ATDC 240 degrees.

  On the other hand, the misfire detection window is set to ATDC 110 to 200 degrees.

  For this reason, as shown in FIG. 14, two types of time measurement windows are set.

  Conventionally, as shown in FIG. 15, time measurement is performed by generating an interrupt for each time measurement window using an input capture interrupt. In this case, an interrupt terminal corresponding to the number of time measurement windows is necessary, which causes an increase in the load of program processing for interrupt processing and the number of CPU terminals.

  Therefore, when an interrupt from the crank angle sensor is generated for each predetermined crank angle unit, one input capture interrupt is generated by measuring the time for each crank angle unit and adding until the predetermined window width is reached. As described above, a plurality of time measurement window widths can be set.

  As shown in FIG. 16, a crank angle sensor signal is input and an interrupt is generated every 10 ° C. Further, the cam angle sensor signal is input to generate an interrupt corresponding to a TDC position of a specific cylinder or a predetermined offset angle position from the TDC.

Offset counter A set for each window by interruption by cam angle sensor signal
Both (for misfire window measurement) and offset counter B (for fuel control window measurement) are reset to zero.

  Thereafter, each time the crank angle sensor signal interrupt is input, the offset counter A and the offset counter B are incremented.

  The set value corresponding to the misfire window measurement start angle is compared with the offset counter A, and when the predetermined counter is reached, the misfire window measurement angle counter and the misfire window measurement time integrated value are reset to zero.

  At the same time, the set value corresponding to the start angle of the fuel control window measurement is compared with the offset counter B, and when the predetermined counter is reached, the fuel control window measurement angle counter and the fuel control window measurement time integrated value are reset to zero.

  Furthermore, the misfire window measurement angle counter and the fuel control window measurement angle counter are incremented, and at the same time, the crank angle interruption interval (passing time of 10 ° C) is added to the misfire window measurement time integrated value and the fuel control window measured time integrated value. To do.

  A threshold corresponding to a predetermined misfire window measurement angle width is compared with a misfire window measurement angle counter. When they match, the misfire window measurement time integrated value is used to start a misfire detection program.

  Further, a threshold value corresponding to a predetermined fuel control window measurement angle width is compared with a fuel control window measurement angle counter, and when they match, the rotation fluctuation detection disclosed in the present embodiment is performed.

1 is an overall configuration diagram of the present invention. The input / output block diagram of a control apparatus. The processing block diagram of this invention. Control timing chart. Operation example (correction method) of fuel increase control. Operation example of correction amount. The flowchart of correction amount calculation. An operation example at the start of air-fuel ratio control. Schematic of torque and rotation fluctuation with respect to air-fuel ratio. Schematic which shows the dispersion | variation in rotation fluctuation. Explanatory drawing of rotation fluctuation calculation. The timing chart of the correction amount calculation for each cylinder. The flowchart of the cylinder specific correction amount calculation. Examples of window settings. Conventional example of crank angle sensor signal interruption. The timing chart of a crank angle sensor signal interruption.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Intake air amount meter 3 Throttle 4 ISC passage 5 ISC valve 6 Intake manifold 7 Fuel injection valve 8 Spark plug 9 Air cleaner 10 Exhaust pipe 11 Catalyst 12 Exhaust sensor 13 Water temperature sensor 14 Crank angle sensor 15 Control device

Claims (8)

In the control device that controls the engine speed of the engine,
The controller is
Measuring the engine speed, calculating a parameter representing the fluctuation of the engine speed, and controlling the fuel injection amount supplied to the cylinder of the engine so as to suppress the fluctuation of the engine speed according to the parameter. Control device characterized. In the control device that controls the engine speed of the engine,
The controller is
The air-fuel ratio engine rotational speed is measured under a condition where the air-fuel ratio is constant, a parameter representing a fluctuation in the rotational speed is calculated, and the fuel injection amount supplied to the engine cylinder is rotated according to the parameter. A control device that performs control so as to suppress fluctuations in the number. In an engine rotation control device that controls the engine speed by controlling the fuel injection amount of the engine,
An engine rotation speed control device that measures an engine rotation speed, calculates a rotation speed fluctuation parameter for each cylinder, and controls a fuel injection amount of a corresponding cylinder according to the rotation speed fluctuation parameter.   4. The engine speed control device according to claim 3, wherein a fuel injection amount of a corresponding cylinder is controlled by measuring a rotational fluctuation at a predetermined air-fuel ratio by air-fuel ratio control. apparatus. In the engine speed control device according to claim 1,
An engine speed control device characterized in that a plurality of post-startup increase values corresponding to fuel volatility are set, and a difference between the post-startup increase values is set as an upper and lower limit value of a fuel injection amount control amount. In the engine speed control device according to claim 1,
An averaging means for calculating a time average value or a moving average value of the ignition timing is provided,
An engine rotation speed control apparatus for controlling a fuel injection amount by providing a correction term based on a value of a time average value or a moving average value of ignition timing in a threshold value or a fuel correction amount for detecting a rotation fluctuation. In an engine speed control device that controls the engine speed by controlling the fuel injection amount of the engine,
A crank angle sensor that generates a signal for each predetermined crank angle, a cam angle sensor that generates a signal for determining a cylinder, and a means for measuring an interrupt generation interval time for each crank angle sensor signal interrupt,
Cam angle sensor signal interruption is set as the reference angular position, the number of occurrences of the crank angle sensor signal is counted up to the angular position shifted by the offset angle, and the position shifted by the offset angle is set as the start position of the window passing time.
An engine speed control device that integrates the generation intervals of crank angle sensor signals until the end angle of the window is reached.   6. The engine speed control apparatus according to claim 5, wherein a plurality of offset angle positions are provided, and a plurality of windows having different window start positions and end positions are prepared.

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