JP6553497B2 - Control device and system for internal combustion engine - Google Patents

Description

  The present invention relates to a control device and system for an internal combustion engine that performs control at an effective arithmetic processing cycle based on sensor input values.

  In recent years, regulations on fuel consumption and exhaust of vehicles such as automobiles are being strengthened, and such regulations tend to become stronger and stronger in the future. The intake air amount to the internal combustion engine is a parameter used for calculating the fuel injection amount, and highly accurate intake air amount detection is indispensable in order to comply with regulations that will become stricter in the future. Since the output result of the air flow sensor for measuring the amount of intake air influences the fuel efficiency and the exhaust performance, technical development for increasing the detection accuracy of the amount of intake air of the air flow sensor is actively performed.

  A hot-air type air flow sensor that is widely used at present as an air flow sensor capable of measuring the amount of intake air is a detection signal of this air flow sensor, and the voltage value is changed according to the amount of air based on the signal from the heating resistor. In many cases, a voltage signal or a frequency signal that changes the cycle of the output pulse according to the amount of air is used.

  Recently, a SENT communication method in which a sensor such as pressure and humidity is mounted on an airflow sensor and a plurality of sensor detection values are transmitted through a single signal line is sometimes used.

  By the way, in the internal combustion engine, since the intake pulsation is generated in the intake pipe due to the reciprocating motion of the piston and the on-off valve operation of the intake valve, the detection signal of the hot wire air flow sensor fluctuates in synchronization with the engine speed and intake pulsation even in the steady state. Occurs.

  In particular, a hot-wire airflow sensor disposed upstream of the throttle valve is easily affected by intake pulsation when the throttle valve is operated to the fully open side. For example, if the detection timing matches a phase with a large air flow rate, an air flow rate larger than the actual air flow rate is detected. Conversely, if the detection timing matches a phase with a small air flow rate, the actual air flow rate is detected. An air flow rate smaller than the flow rate is detected.

  For this reason, Patent Document 1 proposes a method of reducing the influence of intake pulsation by averaging a plurality of sample data. In Patent Document 1, by providing the air flow rate detection timing with a short crank angle interval, the same number of detection values can always be obtained regardless of the change in rotational speed, and between predetermined crank angles for calculating the average flow rate By averaging the detection values, it is less susceptible to pulsation effects.

JP 62-123317 A

  According to the technique described in Patent Document 1, sampling is performed in synchronization with the crank angle interval even if the rotational speed changes, so the same number of samplings can be performed in one rotation, and when operating at a constant rotational speed, The averaged value is considered to indicate the average flow rate.

  However, when the engine speed changes, the elapsed time from the previously sampled detection value to the currently sampled detection value differs. For example, when the rotational speed is increasing, the elapsed time from the previous value to the current value is gradually shortened. Conversely, when the rotational speed is decreasing, the elapsed time from the previous value to the current value is gradually increased.

  For this reason, in the normal averaging process (the average value of the detected values is averaged by the number of detections), the weights of the detected values are different between predetermined crank angles for calculating the average flow rate. There was a problem that it might not be possible.

  The object of the present invention is, in view of such conventional problems, to realize a control device and control system of an internal combustion engine capable of obtaining an accurate average air flow rate value even when the rotational speed of the internal combustion engine fluctuates. It is.

  In order to achieve the above object, the present invention is configured as follows.

A control device for an internal combustion engine that controls the internal combustion engine at a constant arithmetic processing execution cycle, and receives a signal corresponding to the amount of air flowing into the internal combustion engine at a first timing according to the rotational speed of the internal combustion engine. or a sensor value detector for sampling, of the signal detected by the sensor value detector, the elapsed time measuring unit that measures an elapsed time since the last received or sampled signals, the end of one cycle of the operation process execution cycle An average value calculation unit that calculates an average value of signals received or sampled during one period of the arithmetic processing execution cycle at a second timing, and the second timing at the second timing. Using the average value calculated by the value calculation unit, a balance calculation unit that calculates the balance of the amount of air flowing into the internal combustion engine, and a fuel based on the balance calculated by the balance calculation unit A fuel injection amount calculation unit that calculates an injection amount, wherein the average value calculation unit receives each signal received or sampled during one cycle of the calculation processing execution cycle, and receives the previous signal or The products of the elapsed time from the sampled signal are added together, and the added value is averaged over one cycle time of the calculation processing execution cycle, and an average value in one cycle of the calculation processing execution cycle is calculated.

  ADVANTAGE OF THE INVENTION According to this invention, even when the rotation speed of an internal combustion engine fluctuates, the control apparatus and control system of an internal combustion engine which can acquire an exact air average flow value can be implement | achieved.

1 is an overall schematic configuration diagram of an internal combustion engine to which a control device of the present invention is applied. It is the figure which showed the elapsed time from the sensor detected value and the last detected value between arithmetic processing execution cycles. It is an internal block diagram of ECU which calculates an average value using the detected value of the airflow sensor in Example 1 of this invention, and the elapsed time from the last detected value. It is an operation | movement flowchart which calculates an average value using the sensor detection value in Example 1 of this invention, and the elapsed time from the last detection value. It is an internal block diagram of ECU which calculates an average value using the elapsed time from the detected value of an airflow sensor and the last detected value in Example 2 of this invention. It is a flowchart which calculates an average value using the elapsed time from a sensor detected value and the last detected value when it has the balance calculating part which calculates the balance of the physical quantity which a sensor detects. It is the figure which showed the example of the air flow rate at the time of sampling an air flow rate with a predetermined crank angle space | interval. FIG. 6 is a view showing an example in which the air flow rate is sampled at a predetermined crank angle interval while the rotational speed of the internal combustion engine is rising. It is a graph which shows an example in case the reception number of a sensor signal changes between arithmetic processing execution cycles.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
FIG. 1 is an overall schematic configuration diagram of an internal combustion engine to which a control device of the present invention is applied. In FIG. 1, an internal combustion engine 10 is a spark ignition type internal combustion engine having four cylinders, for example, and includes a cylinder 11 including a cylinder head 11 a and a cylinder block 11 b, and is slidable in each cylinder of the cylinder 11. And the piston 15 is connected to a crankshaft (not shown) via a connecting rod 14.

  In addition, a combustion chamber 17 having a ceiling with a predetermined shape is formed above the piston 15, and an ignition plug 35 to which a high ignition signal is supplied from an ignition coil 34 to the combustion chamber 17 of each cylinder. Is being set up.

  The combustion chamber 17 is in communication with an intake passage 20 provided with an air cleaner 19, a throttle valve 25, a collector 27, an intake manifold 28, an intake port 29 and the like. And is sucked into the combustion chamber 17 of each cylinder through an intake valve 21 that is driven to open and close by an intake camshaft 23 disposed at an end of an intake port 29 that is a downstream end of the intake passage 20. It has become.

  A fuel injection valve 30 for injecting fuel toward the intake port 29 is provided for each cylinder in the intake manifold 28 of the intake passage 20.

  An air flow sensor 50 that detects the flow rate of intake air is disposed downstream of the air cleaner 19 in the intake passage 20. In the air flow sensor 50, as the intake air flow rate (mass flow rate) increases, the value of the current flowing through the hot wire (heating resistor) arranged in the intake air flow to be measured increases, and the intake air flow rate decreases. Accordingly, the bridge circuit is configured such that the value of the current flowing through the hot wire decreases.

  Then, the heating resistance current value flowing in the hot wire of the air flow sensor 50 is extracted as a voltage signal, and the ECU (engine control unit (engine control unit) is transmitted by a communication method such as voltage or frequency signal or SENT (Single-Edge Nibble Transmission) communication. )) It is sent to 100.

  An air-fuel mixture of the air taken in through the intake passage 20 and the fuel injected from the fuel injection valve 30 is taken into the combustion chamber 17 through the intake valve 21, and is caused by the spark plug 35 connected to the ignition coil 34. It is burned by spark ignition. Then, the exhaust gas after combustion in the combustion chamber 17 is exhausted from the combustion chamber 17 via the exhaust valve 22 driven to open and close by the exhaust camshaft 24, and exhaust ports, exhaust manifolds, exhaust pipes, etc. (not shown) The air is discharged into the outside atmosphere through the exhaust passage 40 provided.

The exhaust passage 40 is provided with a three-way catalyst 60 for purifying exhaust gas in which platinum, palladium, or the like is applied to a carrier such as alumina or ceria. The upstream side of the catalyst 60 has a pre-catalyst air-fuel ratio. On the other hand, a linear air-fuel ratio sensor 51 having a linear output characteristic is arranged, and on the downstream side of the catalyst 60, for identifying whether the post-catalyst air-fuel ratio is richer or leaner than the stoichiometric (theoretical air-fuel ratio). An O ₂ sensor 52 that outputs a switching signal is provided.

  Further, the fuel injection valve 30 disposed for each cylinder of the internal combustion engine 10 is connected to the fuel tank 53, and the fuel inside the fuel tank 53 is a fuel provided with the fuel pump 54, the fuel pressure regulator 55 and the like. The fuel is adjusted to a predetermined fuel pressure by the supply mechanism and supplied to the fuel injection valve 30.

  The fuel injection valve 30 supplied with fuel at a predetermined fuel pressure is driven to open by a fuel injection pulse signal having a duty (pulse width: corresponding to the valve opening time) according to the operating condition such as engine load supplied from the ECU 100 Then, an amount of fuel corresponding to the valve opening time is injected toward the intake port 29.

  The ECU 100 performs various controls of the internal combustion engine 10, for example, fuel injection control by the fuel injection valve 30 (air-fuel ratio control), ignition timing control by the spark plug 35, and the like based on the accelerator opening signal 70. It has a built-in microcomputer.

  FIG. 2 is a diagram showing the sensor detection value and the elapsed time from the previous detection value during the arithmetic processing execution cycle. In the first embodiment, the case of an air flow sensor is described as an example of the sensor.

  The ECU 100 calculates an average air flow rate based on a detection value obtained by receiving or sampling an airflow sensor signal during one Ten period, for each arithmetic processing execution cycle Ten. The airflow sensor detected values in the Nth Ten period in FIG. 2 are Q1, Q2, and Q3.

  Of the airflow sensor detection values in the (N-1) th Ten period, the detection value received last is Q0.

  In each detection value in the N-th Ten period, the elapsed time from the previous detection value is as follows. In the case of Q1, an elapsed time t1 from Q0 to Q1 and an elapsed time t2 from Q1 to Q2 in the case of Q2 and an elapsed time t3 from Q2 to Q3 in the case of Q3.

  Since it is the elapsed time from the previous detection value, t1 is not the elapsed time from the N-th Ten start time (dotted line) to Q1, but Q0 to N-th Ten detected at the end of the N-1 Ten-period. This is the elapsed time up to Q1 detected at the beginning of the period.

  When sampling the sensor signal at a fixed time period, t1, t2 and t3 show the same value, but when sampling the sensor signal at every predetermined crank angle interval, or when input from the sensor at any timing In the case of receiving a signal or the like, t1, t2, and t3 do not necessarily indicate the same value.

  Therefore, when the detected values in the Nth Ten period are averaged by a normal method to obtain the average air flow rate Qave, Qave = (Q1 + Q2 + Q3) / 3.

  However, in this average value calculation method, the elapsed time from the start time of the N-th Ten to the Q1 is a slight time compared to t2 and t3, which are the elapsed times of Q2 and Q3, and the time ratio in the Ten period is In spite of being small, it is averaged by the same handling method as Q2 and Q3. From the viewpoint of obtaining the average air flow rate during the tenth Ten, the above-described normalization process by the normal method may not be a correct calculation method.

  Therefore, in Example 1 of the present invention, for each detection value (Q1, Q2, Q3), the elapsed time (t1, t2, t3) from the previous detection value is measured, and the average air flow rate Qave in the Ten period is calculated. Calculate The calculation process of the average air flow rate Qave will be described with reference to the block diagrams and flowcharts of FIGS.

  FIG. 3 is an internal block diagram of ECU 100 that calculates an average value using the detected value of airflow sensor 50 and the elapsed time from the previous detected value.

  When a signal from the airflow sensor 5 is input to the ECU 100, the ECU 100 receives or samples the sensor signal at a predetermined timing by the sensor value detection unit 301. Here, when the sensor signal is a signal transmitted by a digital method such as frequency or SENT communication, the ECU 100 receives the signal at a timing inputted from the sensor 50, and the sensor signal is transmitted by a voltage, that is, an analog method. If it is a signal, the ECU 100 performs sampling at a predetermined timing (every predetermined time or every predetermined crank angle interval).

  The sensor detection value Qn detected by the sensor value detection unit 301 measures the elapsed time tn from the previous detection value Qn−1 in the elapsed time measurement unit 302. As a method for measuring the elapsed time, when the sensor signal is a signal transmitted in a digital manner, or when the sensor signal transmitted in an analog manner is sampled at a predetermined time, it is generally performed by an ECU. Use a timer.

  On the other hand, when the sensor signal transmitted in an analog manner is sampled at predetermined crank angle intervals, a timer may be used, or the engine speed and the predetermined crank angle interval may be converted into elapsed time. .

  The arithmetic processing execution flag setting unit 303 sets the arithmetic processing execution flag fen for calculating the average value of the Ten period to 1 at the end of the arithmetic processing execution cycle Ten.

  The average value calculation unit 304 calculates the average value Qave of the sensor detection values during the Ten period when the calculation processing execution flag fen = 1. A specific average value calculation method will be described with reference to FIG.

  FIG. 4 is an operation flowchart for calculating the average value using the sensor detection value and the elapsed time from the previous detection value.

  In FIG. 4, first, at step 401, a signal is input from the air flow sensor 50 to the ECU 100.

  Next, in step 402, the sensor value detection unit 301 receives or samples an input signal from the airflow sensor 50 at a predetermined timing, and detects a sensor value. Here, when the sensor signal is a signal transmitted by digital method such as frequency or SENT communication, the sensor value detection unit 301 of the ECU 100 receives the signal at the timing input from the air flow sensor 50, and the sensor signal has a voltage That is, when the signal is transmitted in an analog manner, the sensor value detection unit 301 of the ECU 100 performs sampling at a predetermined timing (every predetermined time or every predetermined crank angle interval).

  Next, in step 403, the elapsed time measuring unit 302 measures the elapsed time tn from the previous detection value Qn-1 in the sensor detection value Qn. As a method of measuring the elapsed time, when the sensor signal is a signal transmitted in a digital system, or when the sensor signal transmitted in an analog system is sampled at a predetermined time, the ECU 100 is generally performed. Use a timer that works.

  On the other hand, when sampling the sensor signal transmitted by the analog method every predetermined crank angle interval, a timer may be used, or the engine speed and the predetermined crank angle interval may be converted into elapsed time. .

  Next, in step 404, it is determined whether the arithmetic processing execution flag fen set by the arithmetic processing execution flag setting unit 303 is one. When fen = 0, since it is not the timing to calculate the average air flow rate Qave in the Ten period, the sensor detection value Qn and the elapsed time tn from the previous detection value are stored, and the process returns to Step 402.

  In step 404, when fen = 1, since it is the timing to calculate the average air flow rate Qave in the Ten period, the process moves to step 405, and the average value calculation unit 304 detects each sensor detection value in the Ten period and each value. The added value of the products of elapsed time is divided by the added value of each elapsed time to calculate the average air flow rate Qave between Ten. That is, the following equation (1) (an equation embodying the equation in step 405 in FIG. 4) is executed.

Qave = (Q1 · T1 + Q2 · T2 + Q3 · T3) / (t1 + t2 + t3) --- (1)
By weighting using the elapsed time and averaging, it is possible to obtain a correct average air flow rate in consideration of weighting even when the elapsed times between the sampled signals are different.

  In step 406, since the calculation of the average value is complete, the arithmetic processing execution flag setting unit 303 sets the arithmetic processing execution flag fen = 0.

  The average air flow rate Qave calculated by the average value calculation unit 304 is supplied to the fuel injection amount calculation unit 305. The fuel injection amount calculation unit 305 calculates the fuel injection amount based on the supplied average air flow rate Qave. The operation of the fuel injection valve 30 and the like is controlled according to the fuel injection amount calculated by the fuel injection amount calculation unit 305.

  As described above, according to the first embodiment of the present invention, in the case where the air flow rate is detected a plurality of times within the fixed period Ten, the elapsed time from the previous sampling time to the current sampling time is weighted and detected. Since the air flow rate obtained by adding the air amount and dividing the added air amount by the respective elapsed time is used as the average air flow rate for a certain period of time Ten, even if the rotational speed of the internal combustion engine fluctuates, An internal combustion engine control apparatus and control system capable of obtaining a flow rate value can be realized. And a fuel injection valve etc. can be controlled using an exact average air flow rate, and operation control of an internal combustion engine with high precision can be performed.

(Example 2)
Next, a second embodiment of the present invention will be described. The overall configuration of an internal combustion engine to which the control device of the second embodiment is applied is the same as that of the first embodiment, and therefore the illustration and detailed description thereof will be omitted.

FIG. 5 is an internal block diagram of the ECU 100 that calculates an average value using the detected value of the airflow sensor 50 and the elapsed time from the previous detected value in the second embodiment. The difference between the block diagram shown in FIG. 5 in the second embodiment and the block diagram shown in FIG. 3 in the first embodiment is that a balance calculation unit 505 is added to the block diagram in FIG. The average air flow rate Qave calculated by 304 is supplied to the balance calculation unit 505, and the output Qout of the balance calculation unit 505 is supplied to the fuel injection amount calculation unit 305. In other configurations, the example of FIG. 3 and the example of FIG. 5 are equivalent.

  The steps up to the calculation of the average air flow rate Qave by the average value calculation unit 304 are the same as the example shown in FIG. However, since the method of calculating the average air amount is different from that of the first embodiment, a specific method of calculating the average air amount will be described later.

  The balance calculating means 505 calculates the air mass in the collector from the balance of the air flow rate in the collector 27 when the calculation execution flag fen = 1 by the calculation execution flag setting unit 303. Assuming that the flow rate of air flowing into the collector 27 is Qin and the flow rate of air flowing out of the collector 27 into the combustion chamber is Qout, the mass of air accumulated in the collector 27 per arithmetic processing execution cycle is calculated from the difference between Qin and Qout. The air mass in the collector 27 is calculated by calculating and adding the result to the previous value of the air mass in the collector 27.

  Here, the inflow air flow rate Qin is obtained by multiplying Qave itself, which is an average air flow rate per calculation processing execution period Ten, or a correction coefficient set by adaptation. In the air flow sensor 50, an error may occur due to the influence of intake pulsation generated in the intake pipe, and the magnitude and direction (error in the plus direction or minus direction) of the generated error are the engine speed, the valve timing, the air flow rate It depends on the operating conditions of the internal combustion engine.

  For this reason, there is a case where a correction map in which a correction coefficient for absorbing an error of the air flow sensor 50 is set for each operating condition due to adaptation is incorporated in the control. The outflow air flow rate Qout is obtained by obtaining the flow rate of air flowing into the combustion chamber by the balance calculation unit 505 using the air mass in the collector 27, the engine speed, the valve timing, the collector volume, the displacement, the number of engine cylinders, etc. It is calculated.

  FIG. 6 is a flowchart for calculating an average value using the sensor detection value and the elapsed time from the previous detection value in the case of having the balance calculation unit 505 that calculates the balance of physical quantities detected by the sensor as in the second embodiment. It is.

  In step 601 of FIG. 6, a signal is input from the air flow sensor 50 to the sensor value detection unit 301 of the ECU 100.

  Since steps 601 to 604 in FIG. 6 are the same as steps 401 to 404 in FIG. 4, detailed description of steps 401 to 403 is omitted, but will be described from step 604 for convenience of the following description.

  In step 604, it is determined whether or not the arithmetic processing execution flag fen is 1. In step 604, when fen = 0, it is not the timing for calculating the average air flow rate Qave during the Ten period, so the sensor detection value Qn and the elapsed time tn from the previous detection value are stored, and the process returns to step 602. .

  In step 604, when fen = 1, since it is the timing to calculate the average air flow rate Qave in the Ten period, the process moves to step 605, and the average value calculation unit 304 detects each sensor detection value in the Ten period and each value. The added value of the products of the elapsed time is divided by the time of the Ten period, and the average air flow rate Qave in the Ten period is calculated. The point to be noted here is that the denominator (a value obtained by dividing the addition value of the products of the respective sensor detection values and the respective elapsed times between Tens) is different depending on the presence or absence of the balance calculation.

  That is, in the second embodiment, the average air amount Qave during the Ten period is calculated by the following equation (2) (an equation embodying the equation in step 605 in FIG. 6).

Qave = (Q1 · T1 + Q2 · T2 + Q3 · T3) / Ten --- (2)
When the balance calculation is not performed (step 405 in the flowchart of FIG. 4), the product of each sensor detection value and each elapsed time in the Ten period is divided by the added value of each elapsed time, The average air flow rate Qave during the Ten period is calculated. When the balance calculation is performed as in the second embodiment (step 605 in the flowchart of FIG. 6), the sensor detection values and the respective values during the Ten period are calculated. There is a difference that the average air flow rate Qave in the Ten period is calculated by dividing the added value of the products of the elapsed times by the time in the Ten period.

  This is because the timing at which the balance calculation unit 505 performs the balance calculation is performed at the same calculation processing execution period Ten as the timing at which the average value calculation by the average value calculation unit 304 is performed.

  As described above, since the balance calculation calculates the air mass in the collector 27 from the balance of the air flow rate in the collector 27 per calculation processing execution cycle Ten, in step 605, each sensor detection value of Ten period and each progress This is because the added value of the product of time can not be balanced if it is not averaged by the time of Ten period.

  In step 606, since the calculation of the average value has been completed, the arithmetic processing execution flag setting unit 303 sets the arithmetic processing execution flag fen = 0.

  The outflow air flow rate (balance value of the inflow air amount to the internal combustion engine) Qout calculated by the balance calculation unit 505 is supplied to the fuel injection amount calculation unit 305. The fuel injection amount calculation unit 305 calculates the fuel injection amount based on the supplied average air flow rate Qout. The operation of the fuel injection valve 30 and the like is controlled according to the fuel injection amount calculated by the fuel injection amount calculation unit 305.

  As described above, according to the second embodiment of the present invention, it is possible to obtain an accurate average air flow value even in an apparatus that calculates the balance of the air flow rate in the collector 27, and a highly accurate internal combustion engine. A control device and a control system capable of performing operation control can be realized.

  FIG. 7 is a diagram showing an example of the air flow when sampling the air flow at a predetermined crank angle interval. The output signal of the airflow sensor 50 is an analog signal, and the ECU 100 samples the output signal of the airflow sensor 50 at every predetermined crank angle interval, and calculates the elapsed time from the sensor detection value and the previous detection value during the arithmetic processing execution period θen. The average air flow rate Qave during the arithmetic processing execution period θen is calculated.

  Here, since the case of sampling at every crank angle interval θe is described, the calculation process execution cycle is set to θn indicating the angle, and in the example of FIG. 7, five samplings are performed during the calculation process execution cycle θen. Is shown. In this case, the crank angle intervals of the angles θ1 to θ5 are all the same and correspond to an angle interval that is 1/5 of θen. However, when the engine rotational speed changes during the calculation processing execution period θen, even if all the crank angle intervals of θ1 to θ5 are all the same, when the respective angle intervals are converted to time intervals, They appear as different time intervals.

  FIG. 8 is a diagram showing an example in which the air flow rate is sampled at predetermined crank angle intervals while the rotational speed of the internal combustion engine is increasing. The upper diagram in FIG. 8 shows that the rotational speed of the internal combustion engine increases with the passage of time, and the lower diagram in FIG. 8 is a diagram in which the unit of the horizontal axis in FIG. 7 is converted to time. is there.

  Since the time of the predetermined crank angle interval becomes shorter as the rotational speed increases, the angles θ1 to θ5 are all the same crank angle interval in terms of crank angle intervals, but in terms of time intervals, t1> t2 It can be seen that> t3> t4> t5, and the time interval gradually decreases.

  Therefore, in the case of calculating the average air flow rate during the arithmetic processing execution period θen (in terms of time, the sum of the time intervals t1 to t5), it is correct when calculated by (Q1 + Q2 + Q3 + Q4 + Q5) / 5 by the conventional averaging method. Since the average air flow rate cannot be obtained, it is necessary to calculate the average air flow rate by the average value calculation shown in step 405 of FIG. 4 or step 605 of FIG.

  The use of step 405 in FIG. 4 and step 605 in FIG. 6 is determined by whether or not the result of calculating the average air flow rate is used in the balance calculation. When the result of calculating the average air flow rate is not used in the balance calculation, the average air flow rate may be calculated by the average value calculation unit 304 in step 405. When the result of calculating the average air flow rate is used in the balance calculation, the average air flow rate calculated by the average value calculation unit 304 may be used in the balance calculation unit 505 in step 605.

  FIG. 9 is a graph illustrating an example in which the number of sensor signals received during the arithmetic processing execution cycle varies.

  In FIG. 9, the case where the arithmetic processing execution cycle is 2 ms, for example, and the communication system of the air flow sensor 50 is SENT communication will be described. The SENT communication is a communication method for transmitting a signal with a communication cycle of 1 ms or less, and here, consider a case of transmission with a fixed cycle of less than 1 ms (for example, 0.9 ms).

  Since the arithmetic processing execution cycle is 2 ms, the number of sensor signals having a communication cycle of 0.9 ms between 2 ms is basically two, but once every several arithmetic processing execution cycles The number of sensor signals received is three. FIG. 9 shows an interval in which three sensor signals are received in intervals A and B in 2 ms.

  When the cycle in which the number of sensor signal reception changes from two to three sections matches the cycle of intake pulsation, the same part of the pulsation waveform (in FIG. Correspondingly, the number of receptions of sensor signals is three, and the number of receptions of sensor signals is two in other portions.

  Here, when the air flow rate is averaged for 2 ms by the normal averaging method, a constant averaging error occurs in the two reception parts and three parts respectively, which is offset with respect to the correct average air flow Will appear as an error.

  In order to prevent the above-described signal processing error, it is necessary to perform averaging between arithmetic processing execution cycles using sensor detection values and elapsed time as in the present invention.

  In the above-described example, the configuration in which the air flow rate is measured by the air flow sensor has been described. However, the present invention can also be applied to the case where the air flow rate is measured from a signal corresponding to the air flow rate by a measuring element other than the air flow sensor. For example, if the air storage volume is known, if the air pressure is measured, the present invention can be applied to an example in which the air flow rate is measured by considering the temperature and the like.

  Note that the present invention is not limited to the above embodiment as long as the features of the present invention are not impaired, and other embodiments considered within the scope of the technical idea of the present invention are also within the scope of the present invention. included.

DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder, 11a ... Cylinder head, 11b ... Cylinder block, 14 ... Connecting rod, 15 ... Piston, 17 ... Combustion chamber, 19 ... Air cleaner, 20 ... intake passage, 21 ... intake valve, 22 ... exhaust valve, 23 ... intake camshaft, 24 ... exhaust camshaft, 25 ... throttle valve, 27 ... Collector, 28 ... intake manifold, 29 ... intake port, 30 ... fuel injection valve, 34 ... ignition coil, 35 ... ignition plug, 40 ... exhaust passage, 50 ... air flow sensor, 51 ... linear air-fuel ratio sensor, 52 ... _{O 2} sensor, 53 ... fuel tank, 54 ... fuel pump, 55 ... pressure regulator, 60 ... three-way catalyst, 70 -・ ・ Accelerator opening Degree signal, 100... ECU, 301... Sensor value detection unit, 302... Elapsed time measurement unit, 303 ... arithmetic processing execution flag setting unit, 304 ... average value calculation unit, 305. · Fuel injection amount calculation unit, 505 · · · balance calculation unit

Claims (3)

A control device for an internal combustion engine that controls the internal combustion engine at a constant calculation processing execution cycle,
A sensor value detector for receiving or sampling a signal corresponding to the amount of air flowing into the internal combustion engine at a first timing according to the rotational speed of the internal combustion engine;
Of the signal detected by the sensor value detector, the elapsed time measuring unit for measuring an elapsed time from the previous received or sampled signals,
In the second timing is a timing of the completion of one cycle of the operation process execution period, an average value calculation unit for calculating an average value of the received or sampled signals during one cycle of the operation process execution cycle,
A balance calculating unit that calculates a balance of the amount of air flowing into the internal combustion engine at the second timing using the average value calculated by the average value calculating unit at the second timing;
A fuel injection amount calculation unit that calculates a fuel injection amount based on the balance calculated by the balance calculation unit;
With
The average value calculation unit adds each product of each signal received or sampled during one cycle of the arithmetic processing execution period and the elapsed time from the previous reception or sampled signal of the respective signal, The added value is averaged over the time of one operation processing execution cycle, and an average value in one operation processing execution cycle is calculated.
A control device of an internal combustion engine characterized by In the control device for an internal combustion engine according to claim 1,
The sensor value detection unit receives or samples a signal corresponding to an amount of air flowing into the internal combustion engine at predetermined crank angles of the internal combustion engine.
The elapsed time measuring unit measures an elapsed time from a previously received or sampled signal based on the rotational speed of the internal combustion engine and the predetermined crank angle.
A control device of an internal combustion engine characterized by   An internal combustion engine control system for controlling an internal combustion engine at a constant arithmetic processing execution cycle,
An air flow sensor that detects an air flow rate to the internal combustion engine at a first timing according to the rotation speed of the internal combustion engine;
  A sensor value detector for receiving or sampling an air flow rate signal of the air flow sensor;
  An elapsed time measuring unit for measuring an elapsed time from a signal received or sampled last time, of the signal detected by the sensor value detecting unit;
  An average value calculating unit that calculates an average value of signals received or sampled during one cycle of the calculation processing execution cycle at a second timing that is a timing of completion of one cycle of the calculation processing execution cycle;
  A balance calculating unit that calculates a balance of the amount of air flowing into the internal combustion engine at the second timing using the average value calculated by the average value calculating unit at the second timing;
  A fuel injection amount calculation unit that calculates a fuel injection amount based on the balance calculated by the balance calculation unit;
An engine control unit having
  A fuel valve for injecting fuel according to the fuel injection amount calculated by the engine control unit;
Equipped with
  The average value calculation unit adds together products of respective signals received or sampled during one period of the arithmetic processing execution period and elapsed times from previously received or sampled signals of the respective signals. The added value is averaged over one cycle time of the arithmetic processing execution cycle, and an average value in one cycle of the arithmetic processing execution cycle is calculated.
A control system for an internal combustion engine.

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