JP2013142306A - Internal combustion engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine control device capable of precisely determining noise generated in an output signal of a crank angle sensing means.SOLUTION: An internal combustion engine control device includes a crank angle sensing means for emitting a signal each time when a crank shaft of an internal combustion engine rotates at a predetermined angle, a clocking means for clocking an interval T of the signal of the crank angle sensing means, a means for calculating a variation ΔT from a previous interval T to a present interval T, a means for calculating a variation Δ(ΔT) from the previous variation ΔT to the present variation ΔT, and a noise determining means for determining noise generated in the output signal of the crank angle sensing means, when three consecutive variations Δ(ΔT) are negative, positive, and negative in this order.

Description

  The present invention relates to a control device for an internal combustion engine.

  In general, a control device for an internal combustion engine is configured to detect a rotation angle of a crankshaft, that is, a crank angle, by a crank angle sensor and perform various controls and processes based on the detected crank angle. The crank angle sensor generates a signal every time the crankshaft rotates by a predetermined angle. Here, it is assumed that the crank angle sensor generates a signal every time the crankshaft rotates 10 degrees. When the detection value of some sensor, for example, the in-cylinder pressure sensor, is subjected to analog-to-digital conversion (hereinafter abbreviated as “AD conversion”) every time a crank angle sensor signal is input, The value of the in-cylinder pressure can be acquired.

In Patent Document 1, the interval time ΔTi-1 of the previous crank angle sensor signal is equally divided into n to calculate a division time (ΔTi-1) / n, and a predetermined number of divisions are performed from the reference time i of the current pulse signal. A crank angle at timing Ti_k (k = 1, 2,..., N−1) at which time has elapsed is determined as a basic intermediate crank angle i_k, and predetermined parameters such as PV ^κ related to the in-cylinder state at the timing Ti_k. The crank angle i_k ′ is calculated such that the value of is equal to the parameter value at the reference time of the pulse signal in the current or previous period, and the calculated crank angle i_k ′ is compared with the basic intermediate crank angle i_k. A control device for an internal combustion engine that determines whether the basic intermediate crank angle i_k is correct or not is disclosed.

Japanese Patent Laid-Open No. 2007-40208

  The crank angle sensor includes, for example, a timing rotor having teeth with a predetermined angular interval attached to a crankshaft, and a sensor that electromagnetically detects the teeth of the timing rotor. However, noise may occur in the output of the crank angle sensor. Since the ECU recognizes this noise as a normal signal of the crank angle sensor, a deviation occurs between the crank angle recognized by the ECU and the actual crank angle. As a result, the control of the internal combustion engine may be adversely affected.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a control device for an internal combustion engine that can accurately determine noise generated in the output of the crank angle detection means.

In order to achieve the above object, a first invention is a control device for an internal combustion engine,
Crank angle detecting means for generating a signal each time the crankshaft of the internal combustion engine rotates by a predetermined angle;
Time measuring means for measuring an interval time T of the signal of the crank angle detecting means;
Means for calculating a change ΔT between the previous interval time T and the current interval time T;
Means for calculating a change amount Δ (ΔT) between the previous change amount ΔT and the current change amount ΔT;
It is determined that noise has occurred in the output of the crank angle detection means when the values of the three successive variations Δ (ΔT) are in the order of a negative value, a positive value, and a negative value. Noise judging means for
It is characterized by providing.

A second invention is an internal combustion engine control apparatus for achieving the above object,
Crank angle detecting means for generating a signal each time the crankshaft of the internal combustion engine rotates by a predetermined angle;
Time measuring means for measuring an interval time T of the signal of the crank angle detecting means;
Ratio determination for determining whether or not the ratio between the current interval time T, the previous interval time T, and the previous interval time T matches the predetermined ratio range near 1: 1: 1. Means,
A noise determination unit that determines that noise has occurred in the output of the crank angle detection unit when the determination result of the ratio determination unit is not established continuously three times or more;
It is characterized by providing.

The third invention is the first invention, wherein
When the noise determination unit determines that noise has occurred in the output of the crank angle detection unit, the i-th time is the time when the amount of change ΔT has peaked, and the (i-2) -th interval time T T (i-2), (i-1) the interval time T is T (i-1), the i-th interval time T is T (i), and the (i + 1) -th interval time T is When the interval time T of T (i + 1), (i + 2) times is T (i + 2), the ratio of T (i−2): {T (i−1) + T (i)}: T (i + 1) , T (i−1): {T (i) + T (i + 1)}: T (i + 2), and when the former ratio is closer to 1: 1: 1 than the latter ratio (i -1) including means for determining the first signal as noise and determining the i-th signal as noise when the latter ratio is closer to 1: 1: 1 than the former ratio; And features.

Moreover, 4th invention is 2nd invention.
When the noise determination means determines that noise has occurred in the output of the crank angle detection means, the first of the three or more consecutive failures is determined as the i-th, and the (i-2) -th The interval time T is T (i-2), the (i-1) th interval time T is T (i-1), the i-th interval time T is T (i), and the (i + 1) th interval time. When the interval time T is T (i + 1) and the (i + 2) th interval time T is T (i + 2), T (i-2): {T (i-1) + T (i)}: T (i + 1) ) And the ratio of T (i-1): {T (i) + T (i + 1)}: T (i + 2), and the former ratio is closer to 1: 1: 1 than the latter ratio The (i-1) th signal is determined as noise, and when the latter ratio is closer to 1: 1: 1 than the former ratio, the i-th signal is determined as noise. Characterized in that it comprises a.

The fifth invention is the third or fourth invention, wherein
Parameter acquisition means for acquiring a predetermined parameter relating to the operating state of the internal combustion engine each time a signal of the crank angle detection means is generated;
From the parameter data string for each crank angle acquired by the parameter acquisition means, the parameter data for the times determined as noise by the noise determination means are excluded, and the parameter data for the next and subsequent times are excluded. Data string reorganization means to be advanced,
It is characterized by providing.

  According to the first invention, it is possible to accurately determine noise generated in the output of the crank angle detection means.

  According to the second invention, it is possible to accurately determine the noise generated in the output of the crank angle detection means.

  According to the third invention, when it is determined that noise has occurred in the output of the crank angle detection means, it is possible to accurately identify which signal is noise.

  According to the fourth invention, when it is determined that noise has occurred in the output of the crank angle detection means, it is possible to accurately identify which signal is noise.

  According to the fifth aspect, it is possible to appropriately correct the deviation of the parameter data string obtained for each crank angle caused by the influence of noise, and to acquire a correct data string.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a figure which shows the relationship between the output of a crank angle sensor, the crank angle which ECU recognizes, and the timing of AD conversion. It is a figure which shows the relationship between the output of a crank angle sensor, an actual crank angle, the crank angle which ECU recognizes, and the timing of AD conversion. It is a figure which shows the relationship between a crank angle and in-cylinder pressure. It is a figure which shows the data buffer in ECU. It is a figure which shows the relationship between the output of the crank angle sensor at the time of normal time, and the time of noise generation, and interval time T10. It is a figure showing the fluctuation | variation of interval time T10 and variation | change_quantity (DELTA) T10 in the steady time when engine speed is constant. It is a figure showing the fluctuation | variation of the interval time T10 and the variation | change_quantity (DELTA) T10 at the time of the acceleration in which an engine speed increases. It is a figure showing the fluctuation | variation of variation | change_quantity (DELTA) ((DELTA) T10) in the case similar to FIG. It is a figure showing the fluctuation | variation of variation | change_quantity (DELTA) ((DELTA) T10) in the case similar to FIG. It is a figure which shows the relationship between the output of the crank angle sensor at the time of noise generation, and interval time T10. It is a figure for demonstrating the reorganization method of a data sequence. It is a figure which shows the relationship between the output of the crank angle sensor at the time of noise generation, and interval time T10. 14 is a table showing a ratio of a current interval time T10, a previous interval time T10, and a previous interval time T10 in each of the patterns A, B, and C of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a diagram for explaining a system configuration according to the first embodiment of the present invention. As shown in FIG. 1, the system according to the first embodiment of the present invention includes an internal combustion engine 10. The internal combustion engine 10 can be preferably used as a power source for a vehicle or the like, for example. The number of cylinders and the cylinder arrangement of the internal combustion engine 10 are not particularly limited. Each cylinder of the internal combustion engine 10 is provided with a piston 12, an intake valve 14, an exhaust valve 16, a spark plug 18, and a fuel injector 20. In the illustrated configuration, the fuel injector 20 is provided so as to inject fuel into the intake port, but may be provided so as to inject fuel directly into the cylinder. Moreover, although the internal combustion engine 10 of the present embodiment is of a spark ignition type, the present invention can also be applied to a diesel engine or a premixed compression ignition internal combustion engine.

  An intake passage 22 is connected to the main body of the internal combustion engine 10 via an intake manifold (not shown), and an exhaust passage 24 is connected via an exhaust manifold (not shown). A throttle valve 30 for controlling the amount of intake air is arranged in the intake passage 22.

  Further, the system of the present embodiment includes a crank angle sensor 28 for detecting the rotation angle of the crankshaft 26 of the internal combustion engine 10, that is, a crank angle, an in-cylinder pressure sensor 32 for detecting the pressure in the cylinder, and a driver for the internal combustion engine 10. Acceleration position sensor 34 for detecting the load command of the vehicle, various sensors such as an air flow meter (not shown) for detecting the intake air amount, a timer 36 for measuring time, and an ECU (Electronic Control Unit) as control means 50. The various sensors and actuators described above are electrically connected to the ECU 50. The ECU 50 controls the operation of the internal combustion engine 10 by driving each actuator based on information detected by each sensor.

  The in-cylinder volume V is a function of the crank angle, and can be expressed as a function V (θ) when the crank angle is θ. The function V (θ) is determined by the specifications of the internal combustion engine 10 such as the cylinder bore, stroke, and connecting rod length. In the ECU 50, information (formula or map) for calculating the in-cylinder volume V based on the crank angle is stored in advance.

  The ECU 50 acquires the value of the in-cylinder pressure by AD converting the output of the in-cylinder pressure sensor 32. Thus, in the present embodiment, AD conversion of the output of the in-cylinder pressure sensor 32 corresponds to acquiring the value of the in-cylinder pressure. In the following description, AD conversion of the output of the in-cylinder pressure sensor 32 may be simply referred to as “AD conversion”.

Since the in-cylinder pressure value shows a waveform that varies with the crank angle, it can be expressed as P (θ). In the present embodiment, the ECU 50 measures P (θ) for each cycle by performing AD conversion at predetermined crank angle intervals to obtain the in-cylinder pressure value P (θ) for each crank angle. Then, using the waveform of P (θ), or using a calculated value such as P (θ) × V (θ) or P (θ) × V (θ) ^κ (κ is a specific heat ratio), the cycle Each combustion is analyzed, and the control result (hereinafter referred to as “in-cylinder pressure sensor utilization control”) is performed in which the analysis results are reflected in various operation amounts (for example, fuel injection, ignition, valve timing, etc.) of the internal combustion engine 10. be able to.

  The crank angle sensor 28 includes, for example, a timing rotor having teeth with a predetermined angular interval attached to the crankshaft 26, and an electromagnetic sensor (not shown) that electromagnetically detects the teeth of the timing rotor. It has become. This electromagnetic sensor emits an output having a waveform that varies according to the passage of the teeth of the timing rotor. The crank angle sensor 28 generates a signal (pulse signal) having a predetermined crank angle interval corresponding to the interval between the teeth of the timing rotor by shaping the waveform.

  Since one cycle of the internal combustion engine 10 corresponds to two rotations of the crankshaft 26, the crank angle is 0 to 720 °. However, in the present embodiment, the crank angle is represented by an angle from the top dead center (compression top dead center), the crank angle before the top dead center is represented by a number bearing “B”, and after the top dead center. The crank angle is represented by a number bearing “A”. The top dead center is expressed as “TDC”. The unit of the crank angle interval is represented as “CA (Crank Angle)”.

  In the present embodiment, the crank angle sensor 28 generates a signal every time the crankshaft 26 rotates 10 CA. However, noise may occur in the output of the crank angle sensor 28 for some reason. When noise (hereinafter simply referred to as “noise”) generated in the output of the crank angle sensor 28 is input to the ECU 50, the ECU 50 may erroneously recognize it as a normal signal.

  FIG. 2 is a diagram showing the relationship between the output of the crank angle sensor 28, the crank angle recognized by the ECU 50, and the AD conversion timing. FIG. 2 shows a case where no noise is generated (normal time). As shown in FIG. 2, the ECU 50 recognizes the crank angle based on the output of the crank angle sensor 28. That is, the ECU 50 updates (counts up) the recognized crank angle value by 10 CA each time the signal of the crank angle sensor 28 is input at intervals of 10 CA. Further, every time a signal of the crank angle sensor 28 is generated, the ECU 50 AD-converts the output of the in-cylinder pressure sensor 32 in synchronization with the signal and acquires the value of the in-cylinder pressure. When no noise is generated, the ECU 50 can correctly acquire the value of the in-cylinder pressure at the crank angle positions at intervals of 10 CA in this way.

  FIG. 3 is a diagram showing the relationship among the output of the crank angle sensor 28, the actual crank angle, the crank angle recognized by the ECU 50, and the AD conversion timing. FIG. 3 shows a case where noise occurs. As shown in FIG. 3, when noise occurs, the ECU 50 recognizes this noise as a signal of the crank angle sensor 28, counts up the value of the crank angle, and performs AD conversion. As a result, a deviation occurs between the crank angle recognized by the ECU 50 and the actual crank angle. And in the crank angle after noise generation, a shift | offset | difference arises in the correspondence of the crank angle which ECU50 recognizes, and in-cylinder pressure value.

  FIG. 4 is a diagram showing the relationship between the crank angle and the in-cylinder pressure. The left side of FIG. 4 represents the relationship between the actual crank angle and the in-cylinder pressure. The right side of FIG. 4 represents the relationship between the crank angle recognized by the ECU 50 and the in-cylinder pressure when noise occurs. As described above, when noise is generated, the correspondence between the crank angle recognized by the ECU 50 and the in-cylinder pressure value is shifted, so the waveform of the in-cylinder pressure recognized by the ECU 50 (right side in FIG. 4) is actually Unlike the waveform (left side of FIG. 4), the waveform is incorrect. This adversely affects the cylinder pressure sensor utilization control using the cylinder pressure data.

  In the present embodiment, in order to avoid the above-described adverse effects when the noise of the crank angle sensor 28 is generated, the control described below is performed. The ECU 50 AD-converts the output of the in-cylinder pressure sensor 32 every time the signal of the crank angle sensor 28 is input to obtain the in-cylinder pressure value P, and the interval time with the previous signal of the crank angle sensor 28 ( (Period) is measured by the timer 36. This interval time corresponds to the time required for the crankshaft 26 to rotate 10 CA, and is hereinafter represented by the symbol T10. The ECU 50 acquires data of the in-cylinder pressure value P and the interval time T10 over a predetermined crank angle section, and stores it in a buffer. FIG. 5 is a diagram showing a data buffer in the ECU 50. In the present embodiment, as shown in FIG. 5, the data of the in-cylinder pressure value P and the interval time T10 are acquired in the section from B100 to A180. This data acquisition section is a section extended from a section required for the cylinder pressure sensor use control. For example, when in-cylinder pressure data from B100 to A140 is required in the in-cylinder pressure sensor use control, B100 to A180 is set as a data acquisition section as shown in FIG. After acquiring data as shown in FIG. 5 in this way, it is determined whether noise has occurred or not based on the data of the interval time T10. In the following description, as shown in FIG. 5, the signal of the crank angle sensor 28 and the order of data acquired in synchronization therewith are represented by the symbol i.

In the present embodiment, the ECU 50 calculates the amount of change ΔT10 (i + 1) between the previous interval time T10 (i) and the current interval time T10 (i + 1) each time the signal of the crank angle sensor 28 is input, Further, a change amount Δ (ΔT10 (i + 1)) between the previous change amount ΔT10 (i) and the current change amount ΔT10 (i + 1) is calculated, and these values are stored in the data buffer shown in FIG. The change amount ΔT10 and the change amount Δ (ΔT10) are calculated by the following equations.
ΔT10 (i + 1) = T10 (i) −T10 (i + 1)
Δ (ΔT10 (i + 1)) = ΔT10 (i) −ΔT10 (i + 1)

  FIG. 6 is a diagram showing the relationship between the output of the crank angle sensor 28 and the interval time T10 when normal and when noise occurs. As shown in “normal time” in FIG. 6, in the normal case where no noise is generated, the interval time T <b> 10 is constant when the engine speed is constant and constant. Further, each time interval T10 gradually decreases during acceleration when the engine rotational speed increases, and gradually increases during deceleration when the engine rotational speed decelerates. However, the length of the time interval T10 changes extremely compared to the interval time T10 before and after. Absent. On the other hand, when the noise is generated (1) or when the noise is generated (2) in FIG. 6, the noise is generated between the i-th signal and the (i + 1) -th signal of the crank angle sensor 28 in the normal state. ing. In these cases, the ECU 50 erroneously recognizes that the noise is the (i + 1) th time, so that the interval time T10 (i + 1) or T10 (i + 2) becomes extremely shorter than the preceding and following interval times T10.

  FIG. 7 is a diagram illustrating fluctuations in the interval time T10 and the change amount ΔT10 in a steady state where the engine speed is constant. FIG. 7 shows a case where noise is generated in the pattern (1) when noise is generated in FIG. 6 and a normal case where no noise is generated. As shown in FIG. 7, when there is no noise at the steady state, the interval time T10 is constant, so the variation ΔT10 is maintained at zero. On the other hand, when noise occurs, the value of the change amount ΔT10 varies.

  FIG. 8 is a diagram showing fluctuations in the interval time T10 and the change amount ΔT10 during acceleration at which the engine rotation speed increases. FIG. 8 shows a case where noise is generated in the pattern (2) when noise is generated in FIG. 6 and a normal case where no noise is generated. As shown in FIG. 8, when there is no noise at the time of acceleration, the interval time T10 gradually decreases, so the change amount ΔT10 maintains a constant value. On the other hand, when noise occurs, the value of the change amount ΔT10 varies.

  FIG. 9 is a diagram showing the variation of the change amount Δ (ΔT10) in the same case as FIG. As shown in FIG. 9, when there is no noise during steady state, the change amount ΔT10 maintains zero, so the change amount Δ (ΔT10) also maintains zero. On the other hand, when noise occurs, the value of the change amount Δ (ΔT10) varies.

  FIG. 10 is a diagram showing the variation of the change amount Δ (ΔT10) in the same case as FIG. As shown in FIG. 10, when there is no noise during acceleration, the change amount ΔT10 maintains a constant value, so the change amount Δ (ΔT10) maintains zero. On the other hand, when noise occurs, the value of the change amount Δ (ΔT10) varies.

  In FIG. 9, when noise occurs, the change amount Δ (ΔT10 (i + 1)) is a negative (minus) value, the change amount Δ (ΔT10 (i + 2)) is a positive (plus) value, and the change amount Δ (ΔT10 (i + 3). ) Is a negative value. Further, in FIG. 10, when noise occurs, the change amount Δ (ΔT10 (i + 2)) is a negative value, the change amount Δ (ΔT10 (i + 3)) is a positive value, and the change amount Δ (ΔT10 (i + 4)) is negative. It is a value. As described above, in either case of FIG. 9 or FIG. 10, the value of the change amount Δ (ΔT10) is maintained at zero when no noise is generated, and three consecutive change amounts Δ (ΔT10) when noise is generated. ) Values appear in the order of negative, positive, negative. In the present embodiment, the noise of the crank angle sensor 28 is determined using this characteristic.

  That is, the ECU 50 determines that the value of the change amount Δ (ΔT10) for three consecutive times is a negative value and a positive value based on the value of the change amount Δ (ΔT10) for each time stored in the data buffer shown in FIG. , Negative values, and the presence or absence of places in order, and if such places exist, it is determined that noise has occurred, and if such places do not exist, noise is generated Judge that it is not. According to such a noise determination method of the present embodiment, it is possible to accurately determine the presence or absence of noise generation in the crank angle sensor 28 by a simple determination method. Further, since the value (absolute value) of the change amount ΔT10 does not become zero at the time of acceleration or deceleration, it is necessary to set a threshold value in advance when determining the occurrence of noise based on the value of the change amount ΔT10. For this reason, depending on the setting of the threshold, there is a possibility that the presence or absence of noise generation cannot be accurately determined. On the other hand, according to the noise determination method of the present embodiment, it is possible to determine the presence / absence of noise generation based on the sign of the change amount Δ (ΔT10). Can be determined with high accuracy.

  As described above, the example of FIG. 9 and the example of FIG. 10 correspond to the noise occurrence time (1) and the noise occurrence time (2) in FIG. This is a case where the recognized signal is noise. On the other hand, the amount of change Δ (ΔT10 (i + 2)) is a positive value in the example of FIG. 9, and the amount of change Δ (ΔT10 (i + 3)) is a positive value in the example of FIG. For this reason, when the value of the three successive changes Δ (ΔT10) is in the order of a negative value, a positive value, and a negative value, it is possible to determine which signal is noise from that alone. Cannot be identified.

  In the present embodiment, when the occurrence of noise is determined by the above-described method, it is possible to identify which signal is noise as follows. In the example shown in FIG. 7, the value of the change amount ΔT10 has a peak (maximum value) at the (i + 1) th time. That is, the time when the value of the change amount ΔT10 reaches a peak coincides with the time when the signal recognized by the ECU 50 is noise. On the other hand, in the example shown in FIG. 8, the value of the change amount ΔT10 is a peak (maximum value) at the (i + 2) th time. That is, the value of the change amount ΔT10 peaks after one time when the signal recognized by the ECU 50 is noise. Therefore, if the time when the value of the change amount ΔT10 reaches the peak is replaced with the i-th time, it can be said that the i-th or (i−1) -th signal is noise.

  FIG. 11 is a diagram showing the relationship between the output of the crank angle sensor 28 and the interval time T10 when noise occurs. Assuming that the change amount ΔT10 reaches its peak at the i-th time, the (i-1) -th signal is noise as shown in the upper diagram of FIG. The case of noise is the case as shown in the lower diagram of FIG. Therefore, if the case of the upper figure of FIG. 11 and the case of the lower figure can be discriminated, it is possible to identify which signal is noise.

  In the case of the upper diagram in FIG. 11, the sum of T10 (i-1) and T10 (i) corresponds to the original interval time T10. Therefore, in this case, the ratio of T10 (i−2): {T10 (i−1) + T10 (i)}: T10 (i + 1) is 1: 1: 1 when the internal combustion engine 10 is in a steady state. If the internal combustion engine 10 is accelerating or decelerating, the ratio is close to 1: 1: 1.

  On the other hand, in the case of the lower diagram in FIG. 11, the sum of T10 (i) and T10 (i + 1) corresponds to the original interval time T10. Therefore, in this case, the ratio of T10 (i−1): {T10 (i) + T10 (i + 1)}: T10 (i + 2) is 1: 1: 1 when the internal combustion engine 10 is in a steady state. If the internal combustion engine 10 is accelerated or decelerated, the ratio is close to 1: 1: 1.

  Therefore, in the present embodiment, which signal is noise is identified as follows. That is, the ECU 50 sets the ratio of T10 (i−2): {T10 (i−1) + T10 (i)}: T10 (i + 1) when the time when the value of the change amount ΔT10 reaches the peak is the i-th time. , T10 (i−1): {T10 (i) + T10 (i + 1)}: T10 (i + 2) ratios are calculated, and the two are compared. If the former ratio is closer to 1: 1: 1 than the latter ratio, it can be determined that this corresponds to the case in the upper diagram of FIG. 11, and therefore the (i-1) th signal is determined as noise. On the contrary, when the latter ratio is closer to 1: 1: 1 than the former ratio, it can be determined that it corresponds to the case of the lower diagram of FIG. 11, and therefore the i-th signal is determined as noise.

  When noise is generated at a position close to a normal signal of the crank angle sensor 28, T10 (i-1) in the upper diagram of FIG. 11 and T10 (i + 1) in the lower diagram of FIG. 11 become the original interval time T10. Since the values are close, it may be difficult to identify which of the (i−1) -th signal and the i-th signal is noise. According to the method described above, even in such a case, a normal signal and noise can be reliably identified.

  After determining which signal is noise as described above, the ECU 50 reorganizes the data string of in-cylinder pressure values stored in the data buffer of FIG. FIG. 12 is a diagram for explaining a data string reorganization method. The data buffer in FIG. 5 stores data corresponding to the signal of the crank angle sensor 28 from the i-th time corresponding to B100 to the (i + 27) th time corresponding to A180. In the following description, it is assumed that the (i + 7) th signal corresponding to B30 is determined as noise. In this case, P (i + 7) in the data string P (i) to P (i + 27) of the in-cylinder pressure value stored in the data buffer causes the ECU 50 to mistake the noise of the crank angle sensor 28 as a normal signal. The value obtained by AD-converting the output of the in-cylinder pressure sensor 32 is extra data. Actually, P (i + 8), not P (i + 7), is the in-cylinder pressure value at B30. Therefore, as shown in FIG. 12, the ECU 50 excludes the in-cylinder pressure value data P (i + 7) determined as noise, and the in-cylinder pressure value data P (i + 8) ˜ The data string of in-cylinder pressure values is reorganized by raising P (i + 27). As a result, the in-cylinder pressure value data corresponding to A180 is blank, but as described above, the in-cylinder pressure data required for the in-cylinder pressure sensor use control is from B100 to A140. There is no problem. By reorganizing the data string as described above, it is possible to correct the shift in the correspondence between the crank angle recognized by the ECU 50 and the in-cylinder pressure value. Therefore, as shown in FIG. 12, the in-cylinder pressure waveform recognized by the ECU 50 can be corrected from an incorrect waveform (left side in FIG. 12) before correction to an actual correct waveform (right side in FIG. 12). it can. Thereby, in-cylinder pressure sensor utilization control using in-cylinder pressure data can be correctly executed.

  In the present embodiment described above, the case where the in-cylinder pressure value is acquired every time the signal of the crank angle sensor 28 is generated has been described. However, the parameter to be acquired in the present invention is not limited to the in-cylinder pressure value. However, the present invention can be similarly applied to various parameters acquired in association with the crank angle.

  In the first embodiment described above, the crank angle sensor 28 corresponds to the “crank angle detecting means” in the first invention, and the timer 36 corresponds to the “time measuring means” in the first invention. . Further, the ECU 50 calculates the change amount ΔT10 so that the “means for calculating the change amount ΔT” in the first aspect of the invention calculates the change amount Δ (ΔT10) of the “change amount of the first aspect of the invention”. The “means for calculating Δ (ΔT)” is determined as noise when the values of the three consecutive changes Δ (ΔT10) are in the order of negative value, positive value, and negative value. Thus, the “noise determination means” in the first invention AD-converts the output of the in-cylinder pressure sensor 32 at the timing of generation of the signal of the crank angle sensor 28, whereby the “parameter acquisition means” in the fifth invention is By executing the processing described with reference to FIG. 12, the “data string reorganization means” in the fifth aspect of the present invention is realized.

Embodiment 2. FIG.
Next, the second embodiment of the present invention will be described with reference to FIG. 13 and FIG. 14. The description will focus on the differences from the first embodiment described above, and the same matters will be described. Simplify or omit. The present embodiment is the same as the first embodiment except that the method for determining the occurrence of noise is different.

  FIG. 13 is a diagram showing the relationship between the output of the crank angle sensor 28 and the interval time T10 when noise occurs. FIG. 13 shows three cases of patterns A, B, and C. In any case, it is assumed that the (i + 1) th signal is noise. Pattern A represents a case where noise occurs when half of the original interval time T10 has elapsed. Pattern B represents a case where noise occurs when 1/10 of the original interval time T10 has elapsed. Pattern C represents a case where noise occurs when 9/10 of the original interval time T10 has elapsed.

  In the present embodiment, the ECU 50 calculates a ratio between the current interval time T10, the previous interval time T10, and the interval time T10 of the previous time, and the ratio and a predetermined ratio range near 1: 1: 1. It is determined whether or not a match is established. FIG. 14 is a table showing the ratio of the current interval time T10, the previous interval time T10, and the previous interval time T10 in each of the patterns A, B, and C of FIG. When the engine speed is constant and no noise is generated, the ratio of the current interval time T10 to the previous interval time T10 and the previous interval time T10 is 1: 1: 1. The ratio deviates greatly from 1: 1: 1. For this reason, it is possible to determine the occurrence of noise depending on whether the ratio between the current time interval T10, the previous time interval T10, and the previous time interval T10 matches 1: 1: 1. . However, the ratio between the current interval time T10, the previous interval time T10 and the previous interval time T10 may deviate from 1: 1: 1 due to the effect of acceleration or deceleration of the internal combustion engine 10 or rotation fluctuation. It is necessary to consider. For this reason, when it falls within a predetermined ratio range near 1: 1: 1, it is determined that a match is established. In the present embodiment, a predetermined ratio range is within 1 ± 0.2, and it is determined that a match is established within this ratio range. For example, in the case of 1: 0.8: 1.2, it is determined that a match is established.

  As shown in FIG. 14, in the case of the pattern A, there is a state where the ratio between the current interval time T10, the previous interval time T10, and the previous interval time T10 does not agree with the predetermined ratio range. , (I + 1) -th to (i + 4) -th continuous. In the case of the pattern B, the state in which the ratio between the current interval time T10, the previous interval time T10 and the previous interval time T10, and the predetermined ratio range is not satisfied is from the (i + 1) th ( i + 3) Continue 3 times until the first time. Note that the ratio 1: 1: 0.9 at the (i + 4) th time in the case of the pattern B is within the predetermined ratio range, so it is determined that a match is established. In the case of the pattern C, the state in which the ratio between the current interval time T10, the previous interval time T10 and the previous interval time T10, and the predetermined ratio range is not satisfied is the (i + 2) th ( i + 4) Continue three times until the first time. Note that the ratio 1.1: 1.1: 1 at the (i + 1) th time in the case of the pattern C is within the predetermined ratio range, and therefore, it is determined that a match is established.

  Thus, when noise occurs, in any of the patterns A, B, and C, the ratio between the current interval time T10, the previous interval time T10, and the previous interval time T10, and the predetermined ratio range. Failure to coincide with at least three consecutive occurrences. Therefore, in the present embodiment, the ECU 50 determines the occurrence of noise as follows. Every time a signal is input from the crank angle sensor 28, the ECU 50 matches the ratio between the current interval time T10, the previous interval time T10 and the previous interval time T10, and the predetermined ratio range. It is determined whether or not. Then, when the coincidence is not established for three or more times, it is determined that noise has occurred. According to such a noise determination method, it is possible to accurately determine a normal case and a case where noise is generated, and it is possible to accurately determine whether noise has occurred.

  In the present embodiment, when it is determined that noise has occurred, it is possible to identify which signal is noise as follows. As shown in FIG. 14, in the case of the patterns A and B, the match between the ratio of the current interval time T10, the previous interval time T10 and the previous interval time T10, and the predetermined ratio range is not established first. Is the (i + 1) th signal, and this (i + 1) th signal is noise. On the other hand, in the case of the pattern C, the coincidence between the ratio of the current interval time T10, the previous interval time T10, and the previous interval time T10 and the predetermined ratio range is not established first (i + 2). Since this is the first time, it is the next time after the (i + 1) th signal that is noise. Accordingly, when the ratio of the current interval time T10, the previous interval time T10, and the previous interval time T10 and the coincidence of the predetermined ratio range is not established first is replaced with the i-th time, (I-1) It can be said that the first signal is noise.

  Therefore, in the present embodiment, the i-th time when the ratio between the current time interval T10, the previous time interval T10, and the previous time interval T10 and the predetermined ratio range are not satisfied first is determined. In this case, it is identified in the same manner as in the first embodiment which of the i-th signal and the (i-1) -th signal is noise. That is, the ratio of T10 (i−2): {T10 (i−1) + T10 (i)}: T10 (i + 1) and T10 (i−1): {T10 (i) + T10 (i + 1)}: T10 ( The ratio of i + 2) is calculated and compared. When the former ratio is closer to 1: 1: 1 than the latter ratio, the (i-1) th signal is determined as noise. Conversely, when the latter ratio is closer to 1: 1: 1 than the former ratio, the i-th signal is determined as noise. In this way, it is possible to accurately identify which signal was noise.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Piston 14 Intake valve 16 Exhaust valve 18 Spark plug 20 Fuel injector 22 Intake passage 24 Exhaust passage 26 Crankshaft 28 Crank angle sensor 30 Throttle valve 32 In-cylinder pressure sensor 34 Accelerator position sensor 50 ECU

Claims (5)

Crank angle detecting means for generating a signal each time the crankshaft of the internal combustion engine rotates by a predetermined angle;
Time measuring means for measuring an interval time T of the signal of the crank angle detecting means;
Means for calculating a change ΔT between the previous interval time T and the current interval time T;
Means for calculating a change amount Δ (ΔT) between the previous change amount ΔT and the current change amount ΔT;
It is determined that noise has occurred in the output of the crank angle detection means when the values of the three successive variations Δ (ΔT) are in the order of a negative value, a positive value, and a negative value. Noise judging means for
A control device for an internal combustion engine, comprising: Crank angle detecting means for generating a signal each time the crankshaft of the internal combustion engine rotates by a predetermined angle;
Time measuring means for measuring an interval time T of the signal of the crank angle detecting means;
Ratio determination for determining whether or not the ratio between the current interval time T, the previous interval time T, and the previous interval time T matches the predetermined ratio range near 1: 1: 1. Means,
A noise determination unit that determines that noise has occurred in the output of the crank angle detection unit when the determination result of the ratio determination unit is not established continuously three times or more;
A control device for an internal combustion engine, comprising:   When the noise determination unit determines that noise has occurred in the output of the crank angle detection unit, the i-th time is the time when the amount of change ΔT has peaked, and the (i-2) -th interval time T T (i-2), (i-1) the interval time T is T (i-1), the i-th interval time T is T (i), and the (i + 1) -th interval time T is When the interval time T of T (i + 1), (i + 2) times is T (i + 2), the ratio of T (i−2): {T (i−1) + T (i)}: T (i + 1) , T (i−1): {T (i) + T (i + 1)}: T (i + 2), and when the former ratio is closer to 1: 1: 1 than the latter ratio (i -1) including means for determining the first signal as noise and determining the i-th signal as noise when the latter ratio is closer to 1: 1: 1 than the former ratio; Control apparatus for an internal combustion engine according to claim 1, wherein.   When the noise determination means determines that noise has occurred in the output of the crank angle detection means, the first of the three or more consecutive failures is determined as the i-th, and the (i-2) -th The interval time T is T (i-2), the (i-1) th interval time T is T (i-1), the i-th interval time T is T (i), and the (i + 1) th interval time. When the interval time T is T (i + 1) and the (i + 2) th interval time T is T (i + 2), T (i-2): {T (i-1) + T (i)}: T (i + 1) ) And the ratio of T (i-1): {T (i) + T (i + 1)}: T (i + 2), and the former ratio is closer to 1: 1: 1 than the latter ratio The (i-1) th signal is determined as noise, and when the latter ratio is closer to 1: 1: 1 than the former ratio, the i-th signal is determined as noise. Control apparatus for an internal combustion engine according to claim 2, comprising a. Parameter acquisition means for acquiring a predetermined parameter relating to the operating state of the internal combustion engine each time a signal of the crank angle detection means is generated;
From the parameter data string for each crank angle acquired by the parameter acquisition means, the parameter data for the times determined as noise by the noise determination means are excluded, and the parameter data for the next and subsequent times are excluded. Data string reorganization means to be advanced,
The control apparatus for an internal combustion engine according to claim 3 or 4, further comprising:

Images