JPH0617698A - Internal combustion engine controller - Google Patents

Abstract

PURPOSE:To provide an internal combustion engine controller which can attain highly accurate timing control by correcting a reference position error due to repetitive fluctuation. CONSTITUTION:This controller is provided with the second reference position period measuring part 34 which measures the second reference position period T2i, an inter-reference position period measuring part 35 which measures inter- reference position period T3i, and a stationary operation judging part 36 which generates a stationary operation signal F by judging the stationary operating condition of an internal combustion engine based on the fluctuation amount of the first reference position period T1i. Moreover, this controller is also provided with a predictive inter-reference position period computing part 37 which computes a predictive inter-reference position period T3i+1 based on the first reference position period T1i, the second reference position period T2i and the inter-reference position period T3i based on the stationary operation signal. While stationary operation at a fixed speed is being carried out, a control signal for the internal combustion engine is corrected based on the predictive inter-reference position period T3i+1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine controller for controlling fuel injection and ignition timing for each cylinder based on a reference position signal indicating first and second reference positions, and more particularly to an output during steady operation. The present invention relates to an internal combustion engine control device capable of maintaining highly accurate timing control even when torque (angular velocity) changes.

[0002]

2. Description of the Related Art Generally, in an internal combustion engine such as an automobile engine, in order to optimally control fuel injection and ignition timing according to operating conditions, the crank angle reference position for each cylinder is recognized to determine the ignition timing and fuel injection timing. A microcomputer is used to calculate, etc., and control the control timing with a timer.

At this time, the reference position for timing control is
Although it is obtained from the reference position signal, the timing control is actually delayed once from the detection of the reference position signal, so it is desirable to predict and control the next reference position signal. In particular, during transient operation, it is necessary to detect the tendency of periodic fluctuations of the reference position signal, obtain the next predicted reference position period, and correct the control timing.

FIG. 4 is a block diagram showing a conventional internal combustion engine control device. In FIG. 4, reference numeral 1 is a reference corresponding to first and second reference positions (described later) of each cylinder in synchronization with the rotation of the internal combustion engine. Reference position signal generating means for generating the position signal Tθ,
Reference numeral 2 is various sensors for detecting the operating state D of the internal combustion engine, and 3 is control means for controlling the internal combustion engine based on the reference position signal Tθ and the operating state D.

Control means 3 comprising a microcomputer
Is the first reference position cycle T1i based on the reference position signal Tθ.
A cycle measuring unit 31 for measuring (hereinafter simply referred to as a reference position cycle), a prediction reference position cycle calculating unit 32 for calculating a prediction reference position cycle T1i + 1 based on a variation of the reference position cycle T1i,
Timing control unit 33 for controlling the internal combustion engine based on the predicted reference position cycle T1i + 1, the reference position signal Tθ and the operating state D
It has and.

The timing controller 33 controls the reference position signal Tθ.
While recognizing the reference position of each cylinder based on, the control timing (ignition timing etc.) according to the operating condition D is calculated,
The control timing is corrected based on the predicted reference position cycle T1i + 1, and the control signal corresponding to this is output. The control signal from the timing control unit 33 is applied to the ignition coil, the injector and the like (not shown).

FIG. 5 is a perspective view showing a concrete structure of the reference position signal generating means 1, 10 is a cam shaft which rotates in synchronization with rotation of the internal combustion engine, 11 is fixed to the cam shaft 10 and is synchronized with the internal combustion engine. It is a signal plate that rotates. Reference numeral 12 denotes a plurality of slits formed concentrically along the rotation direction of the signal plate 11, the front end of each slit 12 corresponds to the first reference position of each cylinder, and the rear end thereof corresponds to the second reference position. ing. Although not shown here, for example, only one front end of the slit 12 corresponding to a specific cylinder has an offset.

Reference numeral 13 denotes a light emitting element including a photodiode,
Reference numeral 14 denotes a light receiving element formed of a phototransistor, which constitutes a photocoupler arranged to face the slit 12 for generating the reference position signal Tθ, and generates a pulse of the reference position signal Tθ each time it faces each slit 12. .

FIG. 6 is a timing chart showing the reference position signal Tθ. T1i-1 is the previous reference position cycle, T1i is the present reference position cycle, T1i + 1 is the next reference position cycle, and T1i + 1 is the next reference position cycle.
a is a timer control time of the ignition timing, and θa is a crank angle corresponding to the timer control time Ta.

At the reference position signal Tθ, B65 ° (TD
(Crank angle 65 ° before C) is a first reference position corresponding to the maximum advance control position of each cylinder, and B5 ° is a second reference position corresponding to the vicinity of the initial ignition position of each cylinder. Tθ rises at the first reference position B 65 °
It consists of a pulse that falls at the reference position B5 °.

Next, referring to FIGS. 5 and 6, FIG.
The operation of the conventional internal combustion engine controller shown in FIG. When the internal combustion engine rotates, the rotation of the camshaft 10 causes the reference position signal generating means 1 to generate the reference position signal Tθ as shown in FIG.
, Various sensors 2 generate various operating states D,
Each is input to the control means 3.

During normal steady operation, the correction based on the predicted reference position cycle T1i + 1 is unnecessary, and the timing control unit 33 in the control means 3 determines the ignition timing and the ignition timing based on the reference position signal Tθ and the operating state D. A control signal corresponding to the fuel injection timing or the like is output. For example, in the case of ignition control, when the ignition timing is on the advance side in high-speed operation, timer control based on the first reference position B65 ° is performed, and when the ignition timing is on the retard side in low-speed operation. Timer control is performed based on the second reference position B5 °. The power distribution to each cylinder is mechanically performed, for example, via a discharge electrode (not shown) provided on the rotary shaft.

On the other hand, the first reference position cycle measuring section 31 in the control means 3 measures the reference position cycle T1i of the reference position signal Tθ, and the predicted reference position cycle calculating section 32 uses the previous and current reference position cycle T1i. -1 and T1i are used to calculate the next reference position cycle T1i + 1 as the predicted reference position cycle.

That is, the variation amount (T1i-T1i-1) of the reference position cycle from the previous time to this time can be added to the current cycle T1i to obtain the predicted reference position cycle T1i + 1. For example, if the current cycle T1i is shorter than the previous cycle T1i-1 during the transient operation during acceleration, the decrease (T1i-
T1i-1) is reflected in the next cycle T1i + 1. As a result, the timing control unit 33 can correct the control signal with the reference position based on the predicted reference position cycle T1i + 1 as the control reference position and perform optimal timing control.

When the measured reference position cycle T1i is stable and its fluctuation is small, the following equation holds.

T1i-1≈T1i (1)

Therefore, in this case, the next predicted reference position cycle T1i + 1 can be calculated from the following equation.

T1i + 1 = T1i

That is, the current reference position cycle T1i can be directly used as the next predicted reference position cycle T1i + 1. Hereinafter, the timing control unit 33 calculates the control timing based on the reference position signal Tθ and the operating state D, converts the control angle into the control time, and outputs the final control signal based on the predicted reference position cycle T1i + 1. Output. At this time, the control time Ta is calculated by the following equation using the crank angle θ1 corresponding to the control time Ta and the crank angle θ1 (= 180 °) corresponding to the predicted reference position cycle T1i + 1, which is referred to in FIG. It is calculated.

Ta = {(T1i + 1) / θ1} × θa (2)

However, by measuring only the reference position cycle T1i, it is not possible to grasp the variation within the reference position cycle T1i, so that the internal combustion engine cannot be accurately and efficiently driven.

For example, even if the above equation (1) is established, the cycle between the reference positions B65 ° and B5 ° may change. In particular, when the internal combustion engine is operating at a low speed immediately before engine stalling and the output torque (angular velocity) fluctuates, the angular velocity fluctuation within the reference position cycle T1i does large. Such periodic fluctuations within the reference position cycle T1i occur every other ignition cycle due to the characteristics of the four-cycle internal combustion engine, and are therefore called repeated fluctuations.

[0023]

As described above, the conventional internal combustion engine control device detects the fluctuation of the first reference position cycle T1i and corrects the cycle fluctuation of the reference position signal Tθ.
Repetitive fluctuations that occur within the range of the first reference position cycle T1i cannot be detected, and a timing control signal is generated based on the reference position signal Tθ that includes a repetitive fluctuation error, which realizes highly accurate control. There was a problem that I could not do it.

The present invention was made in order to solve the above-mentioned problems, and paying attention to the fact that the repeated fluctuation of the reference position cycle occurs every other time, the reference position error due to the repeated fluctuation is corrected. An object is to obtain an internal combustion engine control device capable of highly accurate timing control.

[0025]

According to a first aspect of the present invention, an internal combustion engine control system includes a second reference position cycle measuring section for measuring a second reference position cycle and a reference position for measuring a cycle between respective reference positions. An inter-cycle measurement unit, a steady operation determination unit that determines a steady operation state of the internal combustion engine based on a variation amount of the first reference position period, and generates a steady operation signal, and a first reference signal in response to the steady operation signal. A prediction reference inter-position cycle calculation unit that calculates a prediction reference inter-position cycle based on the position cycle, the second reference position cycle, and the reference inter-position cycle is further provided.

The internal combustion engine controller according to claim 2 of the present invention further comprises a second reference position cycle measuring section for measuring the second reference position cycle and a reference inter-position cycle measuring section for measuring each reference position cycle. And a steady operation determining unit that determines a steady operation state of the internal combustion engine based on the variation amount of the first reference position cycle to generate a steady operation signal, and an angular velocity variation of the internal combustion engine based on the variation amount of the reference position period. And an angular velocity fluctuation determining unit that determines an angular velocity fluctuation signal, and a predicted reference position interval based on the first reference position cycle, the second reference position cycle, and the reference position interval cycle in response to the steady operation signal and the angular speed fluctuation signal. A prediction reference position period calculation unit that calculates a period is further provided.

[0027]

According to the first aspect of the present invention, the first reference position cycle measured this time,
The predicted reference inter-position cycle is calculated based on the second reference position cycle and the reference inter-position cycle, and the control signal for the internal combustion engine is corrected based on the predicted reference inter-position cycle. This corrects the variation error of the reference position signal and enables timing control based on the accurate crank angle reference position.

Further, according to the second aspect of the present invention, it is considered that the fluctuation is repeated during the steady operation and the angular velocity fluctuation, and the prediction is made based on the first reference position cycle, the second reference position cycle and the reference inter-position cycle measured this time. A cycle between reference positions is calculated, and a control signal for the internal combustion engine is corrected based on the predicted cycle between reference positions. This corrects the variation error of the reference position signal and enables the timing control based on the accurate crank angle reference position.

[0029]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a first embodiment of the present invention, in which 1, 2, 31 and 32 are the same as those described above. or,
3A and 33A correspond to the control means 3 and the timing control unit 33, respectively.

Reference numeral 34 is a second for measuring the second reference position cycle T2i.
Reference position cycle measuring unit, 35 is a reference position cycle measuring unit that measures a reference position cycle T3i between the first reference position and the second reference position, and 36 is based on the variation amount of the first reference position cycle T1i. A steady-state operation determination unit that determines a steady-state operation state of the internal combustion engine and generates a steady-state operation signal F, 37 is responsive to the steady-state operation signal F, and is responsive to the first reference position cycle T1i, the second reference position cycle T2i, and the reference position interval. Prediction inter-reference-position cycle T3i + 1 based on cycle T3i
Is a predictive reference position period calculation unit that calculates

In this case, the timing control unit 33A calculates the control signal based on the reference position signal Tθ and the operating state D, and also corrects the control signal by using the predicted reference position cycle T1i + 1 during the transient operation to make the steady state. During operation, the control signal is corrected by using the cycle T3i + 1 between predicted reference positions.

FIG. 2 is a timing chart for explaining the operation of the first embodiment, where T3i-1 is the previous reference position cycle and θ3 (= 60 °) is the predicted reference position cycle T3i + 1 crank angle. Is. First reference position B65 ° and second reference position B5 °
The reference position period T3i between the reference position signal Tθ and the reference position signal Tθ is H
It corresponds to the pulse width of the level section.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. First, with the rotation of the internal combustion engine, the reference position signal Tθ consisting of the pulses shown in FIG. 2 has a first reference position cycle measuring unit 31, a second reference position cycle measuring unit 34, and a reference position cycle in the control means 3A. It is input to the measuring unit 35 and the timing control unit 33A. Further, the operating state D is input to the timing control unit 33A. In the transient operation, the timing control unit 33A corrects the control signal based on the predicted reference position cycle T1i + 1 as described above.

On the other hand, the second reference position cycle measuring section 34 measures the second reference position cycle T2i for each falling edge of the reference position signal Tθ, and the inter-reference-position cycle measuring section 35 measures the reference position corresponding to the pulse cycle. The inter-cycle T3i is measured. Further, the steady operation determination unit 36 compares the difference between the first reference position cycle T1i-1 of the previous time and the first reference position cycle T1i of this time with the predetermined value α, and the following (3)
If the formula is satisfied, it is determined that the internal combustion engine is in a stable rotation state, the steady operation signal F is output, and the predicted reference position position period calculation unit 37 is enabled.

│T1i- (T1i-1) │≤α (3)

In response to the steady operation signal F, the predictive reference inter-position cycle measuring unit 37 predicts the reference inter-position cycle T3i + 1 based on each of the reference position cycles T1i and T2i and the inter-reference position cycle T3i.
Is calculated and input to the timing control unit 33A. As a result, the timing control unit 33A uses the prediction reference inter-position cycle T3i + 1 preferentially over the prediction reference position cycle T1i + 1 to correct the control signal by the prediction reference inter-position cycle T3i + 1.

Here, a method for calculating the prediction reference position period T3i + 1 will be described in detail. As is clear from FIG. 2, the following formula is generally established during each cycle.

(T3i-1) = (T1i-1) + T3i-T2i (4)

Since the above equation (1) is established during steady operation, equation (4) can be rewritten as follows.

(T3i-1) = T1i + T3i-T2i (5)

If, during steady operation, the fluctuations occur repeatedly every other ignition cycle, the previous reference position cycle T3i-1 and the next reference position cycle, that is, the predicted reference position cycle T3i + 1, are generated. Since they are equal, the following equation holds.

(T3i + 1) = T1i + T3i-T2i (6)

Thus, each cycle T1i, which is the measured value this time, is
From T3i to T3i, the period T3i between predicted reference positions is calculated based on the equation (6).
+1 can be calculated. The timing control unit 33A is
Using the cycle T3i + 1 between the predicted reference positions, the control time Ta in which the cycle fluctuation error is corrected is calculated as follows.

Ta = {(T3i + 1) / θ3} × θa (7)

As a result, highly reliable and accurate internal combustion engine control is realized.

Example 2. In the first embodiment, the timing control unit 33A corrects the control signal based on the predicted inter-reference-position period T3i + 1 regardless of the presence or absence of repeated fluctuation during steady operation, but repeated fluctuation occurs. It is desirable to perform the correction based on the cycle T3i + 1 between predicted reference positions only at this time. Because, as shown in FIG.
Since the inter-reference-position cycle T3i depends on the machining accuracy of the slit 12, performing the correction based on the inter-reference-position cycle T3i in the steady operation and in the state where the repeated fluctuation does not occur adds an error. is there.

FIG. 3 is a functional block diagram showing the second embodiment of the present invention, and 3B, 33B and 37B correspond to the control means 3A, the timing control section 33A and the prediction reference position position cycle calculation section 37, respectively. . Reference numeral 38 denotes an angular velocity fluctuation determination unit inserted between the reference position period measurement unit 35 and the predicted reference position period calculation unit 37B, which determines the angular velocity fluctuation of the internal combustion engine based on the variation amount of the reference position period T3i. Then, the angular velocity fluctuation signal R is generated and the prediction reference inter-position period calculation unit 37B is enabled.

In this case, the prediction reference position period calculation section 37B
Calculates the predicted inter-reference-position period T3i + 1 in response to both the steady operation signal F and the angular velocity fluctuation signal R (repetitive fluctuation). In addition, the steady operation signal F is input to the timing control unit 33B together with the period T3i + 1 between predicted reference positions.

The angular velocity fluctuation determination unit 38 compares the difference between the last reference position cycle T3i-1 and the current reference position cycle T3i with a predetermined value β, and if the following equation (8) is satisfied, The angular velocity fluctuation signal R is generated on the assumption that the angular velocity fluctuation is occurring in the engine.

| T3i- (T3i-1) | / T1i ≧ β (8)

That is, as shown in FIG. 2, the magnitude of the pulse duty fluctuation amount (normalized periodic fluctuation amount) of the reference position signal Tθ is determined. In addition, the predicted inter-reference-position cycle calculation unit 37B uses the steady operation signal F and the angular velocity fluctuation signal R.
In response to this, the repeated fluctuation state is determined, and the predicted reference inter-position period T3i + 1 based on the above equation (6) is calculated.

When the period T3i + 1 between predicted reference positions is input, the timing control unit 33B recognizes that it is in the steady operation state and the angular velocity fluctuation (repetitive fluctuation) is generated, and the cycle T3i + 1 between predicted reference positions is recognized. The control signal is corrected based on or,
When the steady operation signal F is input and the angular velocity fluctuation signal R is not input, it is recognized as a complete steady operation state in which no repeated fluctuations occur. Therefore, since it is not necessary to consider the periodic fluctuation error of the reference position signal Tθ, the control signal based on the reference position signal Tθ of this time is output without correction.

[0053]

As described above, according to claim 1 of the present invention, the second reference position cycle measuring section for measuring the second reference position cycle and the reference inter-position cycle measuring section for measuring each reference position cycle. And a steady-state operation determination unit that determines a steady-state operation state of the internal combustion engine based on the variation amount of the first reference position cycle to generate a steady-state operation signal, and a first reference position cycle, 2 A prediction reference inter-position cycle calculation unit that calculates a prediction reference inter-position cycle based on the two reference position cycles and the inter-reference-position cycle, and at the time of steady operation with a constant rotation speed, the internal combustion engine based on the prediction reference inter-position cycle Since the control signal for is corrected, it is possible to obtain the internal combustion engine control device capable of correcting the reference position error due to the repeated fluctuations and performing highly accurate timing control.

According to a second aspect of the present invention, a second reference position cycle measuring section for measuring the second reference position cycle, a reference inter-position cycle measuring section for measuring each reference position cycle, and a first
A steady operation determination unit that determines a steady operation state of the internal combustion engine based on the variation amount of the reference position cycle to generate a steady operation signal, and an angular velocity variation of the internal combustion engine is determined based on the variation amount of the reference position period. An angular velocity fluctuation determining unit that generates an angular velocity fluctuation signal, and a predicted inter-reference-position period based on the first reference position period, the second reference position period, and the inter-reference position period in response to the steady operation signal and the angular velocity fluctuation signal. A predictive reference inter-position period calculation unit is further provided, and the control signal for the internal combustion engine is corrected based on the predicted reference inter-position period during steady operation and angular velocity fluctuation. There is an effect that the internal-combustion-engine control device capable of correcting the position error and removing unnecessary correction and capable of highly accurate timing control is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the first embodiment of the present invention.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional internal combustion engine controller.

FIG. 5 is a perspective view showing a general reference position signal generating means.

FIG. 6 is a timing chart showing an operation of a conventional internal combustion engine control device.

[Explanation of symbols]

 1 Reference Position Signal Generating Means 2 Various Sensors 31 1st Reference Position Cycle Measuring Unit 32 Prediction Reference Position Cycle Measuring Units 33A, 33B Timing Control Unit 34 2nd Reference Position Cycle Measuring Unit 35 Reference Position Cycle Measuring Unit 36 Steady Operation Judgment Unit 37, 37B Prediction reference position period calculation unit 38 Angular velocity fluctuation determination unit B65 ° First reference position B5 ° Second reference position D Operating state F Steady operation signal R Angular velocity fluctuation signal Tθ Reference position signal T1i First reference position period T1i + 1 Prediction Reference position cycle T2i Second reference position cycle T3i Reference position cycle T3i + 1 Prediction reference position cycle

Claims (2)

[Claims] 1. The first of each cylinder is synchronized with the rotation of the internal combustion engine.
Reference position signal generating means for generating reference position signals corresponding to a reference position and a second reference position, various sensors for detecting an operating state of the internal combustion engine, and a first reference position for measuring a cycle of the first reference position. A cycle measuring unit, a prediction reference position cycle calculating unit that calculates a prediction reference position cycle based on the variation amount of the first reference position cycle, and a control signal for the internal combustion engine based on the reference position signal and the operating state. A timing control unit that corrects the control signal based on the predicted reference position cycle, and a second reference position cycle measurement unit that measures the cycle of the second reference position, An inter-reference-position cycle measuring unit that measures a cycle between the first and second reference positions, and a steady operation state of the internal combustion engine is determined based on a variation amount of the first reference position cycle. A steady operation judgment unit for generating a steady operation signal Te in response to the steady operation signal, the first reference position period,
A prediction reference inter-position cycle calculation unit that calculates a prediction reference inter-position cycle based on the second reference position cycle and the reference inter-position cycle, and the timing control unit includes the prediction reference inter-position cycle during the steady operation. An internal combustion engine controller, wherein the control signal is corrected based on a cycle. 2. The first of each cylinder is synchronized with the rotation of the internal combustion engine.
Reference position signal generating means for generating reference position signals corresponding to a reference position and a second reference position, various sensors for detecting an operating state of the internal combustion engine, and a first reference position for measuring a cycle of the first reference position. A cycle measuring unit, a prediction reference position cycle calculating unit that calculates a prediction reference position cycle based on the variation amount of the first reference position cycle, and a control signal for the internal combustion engine based on the reference position signal and the operating state. A timing control unit that corrects the control signal based on the predicted reference position cycle, and a second reference position cycle measurement unit that measures the cycle of the second reference position, The inter-reference-position cycle measuring unit that measures the cycle between each of the reference positions, and the steady operation state of the internal combustion engine is determined based on the variation amount of the first reference position cycle. A steady operation determination unit that generates a signal, an angular velocity variation determination unit that determines an angular velocity variation of the internal combustion engine based on a variation amount of the reference position period, and an angular velocity variation determination unit, the steady operation signal and the angular velocity. In response to a fluctuating signal,
A prediction reference inter-position cycle calculation unit that calculates a prediction reference inter-position cycle based on the first reference position cycle, the second reference position cycle, and the reference inter-position cycle; An internal combustion engine control device, wherein the control signal is corrected based on the predicted reference position-to-position period when the engine is in steady operation and angular velocity changes.