JPS59208164A - Control method of internal-combustion engine - Google Patents

Abstract

PURPOSE:To make ignition timing so as to remain unlagging even if an engine speed varies, by compensating the ignition timing according to a periodic variation in a signal indicating a crank angle. CONSTITUTION:Signals of a signal T24 out of a turning angle detector 12 indicating a crank angle to be produced between signals T04 out of another turning angle detctor 13 indicating a top dead point are counted. And, the next ignition timing is compensated according to pulse numbers of the T24 between the last signal T04. With this constitution, ignition takes place with ignition timing control in accord with the driving state of an engine even if its speed varies, so that the engine can be driven in optimum conditions all the time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the operation of an internal combustion engine, and more particularly, to a method for controlling the operation of an internal combustion engine, and in particular, by performing interpolation calculations between crank angle signals, the 1! The present invention relates to a method for controlling the operation of an internal combustion engine, which calculates the rotation angle of the crankshaft and controls the ignition timing, etc. of the engine based on the calculated rotation angle of the crankshaft.

Generally, in an internal combustion engine operation control method that controls ignition timing, fuel injection timing, etc. based on the rotation angle of the engine crankshaft, the rotation angle of the crankshaft is detected by a rotation angle detector. As this rotation angle detector, for example, there is a photoelectric rotation angle detector, and as shown schematically in FIG. Rotate to g! 2, and then drill a predetermined number of through holes 2α on the same circumference of the rotating plate 2 at positions corresponding to the predetermined rotation angles of all crankshafts, and align them through the through holes 2a. A light emitting element 3 and a light receiving element 4 are arranged facing each other. As the rotary plate rotates 20 times, the light from the light emitting element 3 is interrupted, and the light receiving element 4 converts this interrupted light into an electric pulse signal, which supplies the electric pulse signal to a control processing device (not shown). .

If the rotation ratio of the rotating plate 2 is set to 1/2 of the rotation of the crankshaft, and if the rotation angle of the crankshaft is to be detected in units of 1 degree, for example, the number of through holes 2α must be 720.
Must be. Moreover, in order to avoid interference between adjacent electric pulse signals corresponding to the rotation angle of the crankshaft, it is necessary to increase the distance between adjacent holes 2α to a certain extent, and for this purpose, the Vi co-rotating plate 2 must be made large. Otherwise, the size of the rotation angle detector will inevitably increase.This problem is not limited to the tip tube type, but also applies to other types of rotation angle detectors, such as magnetic types.

Therefore, every time the crankshaft rotates by a predetermined angle, for example, 3011i, a rotation angle signal (crank angle signal) of the crankshaft is generated.
, and reduce the number of through holes 2α to make the 101 rotation angle detector more compact).On the other hand, there is a method to find the rotation angle of the crankshaft of 30 degrees or less by compensating the crank angle signal. .

However, with the method of calculating the rotation angle of the crankshaft by simply interpolating the crank angle, the calculated rotation angle of the crankshaft and the actual rotation angle of the crankshaft match accurately when the engine speed is constant. ,engine(
b) When the rotation speed changes, for example when idling immediately after starting, the intervals between crank angle signals are not equal, and an error occurs between the calculation result and the actual crankshaft rotation angle, resulting in accurate ignition timing. is not obtained.

The present invention has been made in view of the above-mentioned points, and the present invention is made by interpolating the period of the crank angle signal generated every time the engine crankshaft rotates by a predetermined angle to rotate the front F crankshaft at a predetermined rotation angle equalization. Angle sum a; L, in an internal combustion engine control method that controls ignition timing or fuel injection timing based on this calculated rotation angle, the time ratio of a predetermined crank angle signal m1 before the crank angle position of ignition or fuel injection is To provide an engine control method capable of accurately controlling ignition timing, fuel injection timing, etc. even when the engine speed changes by calculating the rotation angle and correcting the calculated rotation angle based on the time ratio. With the goal.

An embodiment in which the control method of the present invention is applied to ignition timing control will be described with reference to the drawings.

FIG. 2 is a block diagram illustrating the entire ignition timing control device.

In Figure 2, center: 6Ii arithmetic processing unit (lower CpU
Electronic control unit (hereinafter referred to as E) equipped with
CU) 10 includes an intake pipe absolute pressure sensor (hereinafter referred to as PB) disposed at the intake Tf (not shown) of the internal combustion engine.
7-4 signal from the rotation angle detector 13 (Fig. 4(b)), which detects the position near the top dead center of each cylinder of the crankshaft (for example, 4 cylinders). , and No. 44 (Fig. 4 (α)) from the rotation angle detector 12 that sequentially detects the rotation angle of the crankshaft are input.Then, the ECU 10 receives these three inputs. The ignition timing is calculated based on the signal, and the ignition circuit 14 is activated at the predetermined ignition timing.
An ignition control signal is output to the ignition coil 15 to intermittently energize the tj flow to the primary shaft coil of the ignition coil 15, thereby generating a high voltage in the secondary coil of the ignition coil 15. This ignition coil 15-2
The high voltage generated in the next coil is distributed to the spark plugs 17 of each cylinder by the distributor 16.

FIG. 6 is a block diagram showing the internal configuration of ECU'ID shown in FIG. 2.

The input terminal of the ECUlo waveform shaping EoJ path 101 is connected to the output terminal of the rotation angle detector 12, the output terminal is connected to the input terminal 102α of the CPU 102, and the input terminal of the waveform shaping circuit 103 is connected to the output terminal of the rotation angle detector 13. , the output terminal is C
Connected to input terminal 10:26 of PU 102. The input terminal of the level correction circuit 1040 is the output terminal of the PB sensor 11, and the output terminal is the analog-digital converter 105.
The output terminal of the analog-to-digital converter is connected to the input terminal 102c of the CPU 102. The output terminal 102d of the CPU 1Q')- is connected to the input terminal of the ignition circuit 14 (FIG. 2, 1).

The CPU 102 counts the pulse period of the electric signal (FIG. 4(b)) whose waveform has been shaped by the waveform shaping circuit 103 using clock pulses and outputs the engine rotational speed Nef%, and the waveform is shaped by the waveform shaping circuit 1o1 and outputs To4. T2424c (Fig. 4(α)) and T2424c (Fig. 4(α)) in which the signal signal constant number, for example, 6, are generated. 4
The rotation angle of the crankshaft is calculated based on the signal.

Here, as shown in Fig. 4 (α) and (b), the Tt4 signal from the generation of an electric signal until the generation of the next electric signal is
Numbered Maroji 1, '2, 3, 4, 5, 6, 1
The period from the falling edge of the th T,4 signal to the falling edge of the second '24 signal is called stage 1, and the same goes for stage 2.
...It's called stage 6. The interval between each stage corresponds to a rotation angle of 30 degrees of the crankshaft.

Therefore, if the fall of the first '24 signal is the top dead center position (hereinafter referred to as TDC) for each cylinder, the fall of the sixth T24 signal is at vertical 0 degrees 3 front of TDC. Nashi, fifth 6. The time when the signal falls is 0 degrees in front of the 6th seat in front of TDC. Similarly, the intervals between stages 1 to 2 vary depending on the engine speed. 7 each for 1st to 6th. The period of the signal, that is, the time of stages 1 to 2 is expressed as 1 to T6, respectively.

The CPU 102 also reads the output signal sound level of the PB sensor 11 through the output signal sound level correction circuit 104 and the analog-to-digital converter 105, and adjusts the engine operating state at that time based on the intake pipe absolute pressure pB and the engine speed Ve mentioned above. The optimum ignition angle for zero wheels is calculated according to a control program to be described later. Then, based on the calculated ignition angle θ and the rotation angle of the crankshaft, the ignition timing is calculated according to the control program shown in FIG. C)) is outputted to the output terminal 102cL and applied to the ignition circuit 14 (FIG. 2). This ignition timing control signal is a pulse signal that falls when the content of an ignition counter, which will be described later, becomes zero.

The ignition circuit 14 starts energizing the primary coil of the ignition coil 15 from the rising edge of the ignition timing control signal, and cuts off the primary heavy current at the falling edge of the ignition timing control signal to perform ignition.

FIG. 5 is a flowchart showing one embodiment of a control program executed by the 1ri CPU 102.

When the ignition switch is turned on, this program outputs 1 h1. First, in step 1 of the main control program, the ECU
lo is initialized, and the process proceeds to step 2, where it is determined whether the value of a stage counter, which will be described later, is 1, that is, whether the current stage is stage 1 or not.

If the determination result in step 2 is positive (Yes), P
The intake pipe absolute pressure PR from the B sensor 11 is taken in (step 6), and then the T. The engine rotation speed N e f is calculated from the pulse period of the 4 signals (step 4).

Then, from these PB values and Ne values, an ignition angle oLg suitable for the engine operating condition is calculated (step 5).
. This '6AW- of 08g is read out from values stored in advance in the memory corresponding to the operating state of the engine represented by the PB value and Ne value, for example.

If the determination result in step 2 is negative (No), then U
When the calculation of step 5 is completed, go to step 2 again.
Proceed to. That is, the calculation of the ignition angle θig is performed at stage 1 in the main control program shown in steps 1 to 5.
will be executed during the period.

Furthermore, in this program, when the 124 signal No. 1 is supplied to the CPU 102 before the execution processing of step 2 of the main control program, the interrupt processing program is executed.

This interrupt processing program @
JF is issued, and first the value of the stage counter is incremented by 1 (step 10). This stage counter is T. When the 4 signal is supplied to the CPU 102, it is reset to zero, and the value 1 is added each time the p1 interrupt processing program is read. That is, when the stage counter is 1, the current stage is stage 1, and when the stage counter is 2, @ indicates stage 2. Similarly, when the contents of the stage counter are 3.4 and 5.6, it indicates that the current stage is stage 4.5.6, respectively.

Next, the process proceeds to step 11, and it is determined whether or not the content of the stage counter is 6. If the result of this determination is negative (#O), the process proceeds to the next step 12.

In step 12, it is determined whether the content of the stage counter is 3 or not, and if the determination result is affirmative (Ygy), the process proceeds to step 13. In step 16, it is determined whether the ignition angle θ calculated in step 5 is greater than 30 degrees, and if the determination result is affirmative (Yes), if the ignition angle θ is greater than 60 degrees, the ignition The value obtained by subtracting 60 degrees from the angle θig is set as the new ignition angle θ→ (step 14), and stage 5 is designated as the ignition zone (step 15), and the execution of this interrupt processing program is terminated and the main control program is returned. return.

If the determination result in step 13 is negative, that is, if the ignition angle θig is 60 degrees or less, the ignition zone is set and stage 6 is designated (step 16), and the execution of this interrupt processing program is terminated and the main control program is Return to

If the determination result in step 12 is negative (NO), the process proceeds to step 17, where it is determined whether the content of the stage counter is 4 or not. If the result of this determination is affirmative (Yes), the process proceeds to step 18, where it is determined whether the ignition zone is in stage 6 or not.

If the determination result in step 18 is negative (No), that is, if the ignition zone is at stage 5, the value corresponding to the ignition angle θ set in step 14 is set in the ignition counter (step 19), and then step Proceed to step 20.

In step 20, the non-energizing time of the ignition coil 15 (Fig. 2) is determined, the candy corresponding to this non-energizing time is set in the non-energizing counter, the execution of this interrupt processing program is ended, and the process returns to the main control program. .

The non-energizing time is the time after ignition is performed, that is, the time when the ignition coil 1
This is the time after energization to the primary coil of No. 5 is interrupted and when energization is started for the next ignition. The energization time is approximately 4 to 4 feet, so that the ignition energy is approximately 4 feet.
5 m, s, and as the engine speed HB increases, the energization times required for successive previous and subsequent ignitions overlap, and ignition, that is, current interruption, is no longer performed. Therefore, in order to secure the emergency time and ensure that the ignition is carried out reliably, the de-energization period is set for a predetermined period of time, e.g.
5m, when it is less than 1.5m, the de-energization time is 1.5m, t
Set to . Therefore, if the engine speed increases,
Needless to say, the energization time becomes shorter.

If the determination result in step 18 is affirmative (Yet), that is, if the ignition zone is at stage 6, step 20
After setting the de-energization time, the interrupt processing program ends and returns to the main control program.

If the determination result in step 17 is negative (No), the process proceeds to step 21, where it is determined whether the content of the stage counter is 5 or not. If the result of this determination is negative (NO), that is, if the current stage is stage 2, execution of the interrupt processing program is ended and the process returns to the main program.

This is because, in this embodiment, the stage 2 period is idle time, and if necessary, other performance expenses 2 processing may be performed during the stage 2 period.

If the determination result in step 21 is affirmative (Yes), the process proceeds to step 22, where it is determined whether the ignition zone is in stage 6 h5. If this determination result is affirmative (Yg, r), the value corresponding to the ignition angle θtg calculated in step 5 is set in the ignition counter (step 23), the execution of the interrupt processing program is completely completed, and the process returns to the main control program. .

If the determination result in step 22 is negative (jVo), that is, if the current stage is stage 5 and the ignition zone is stage 5, the process proceeds to step 24, where the ignition counter is started and this interrupt processing program is executed. Exit and return to the main program.

The ignition counter is a down counter, and ignition is performed when the value set in the ignition counter is subtracted and reaches zero. At this time, the content of the ignition counter is the value set in step 19, and ignition is performed in stage 5. When the ignition counter reaches zero, the aforementioned de-energization counter starts, and until the value of the de-energization counter reaches zero, power to the ignition coil is prohibited.

If the determination result in step 11 is affirmative (Yes), that is, if the current stage is stage 6, then the process proceeds to step 25, where it is determined whether the ignition zone is stage 5 or not. If the result of this determination is negative (NO), that is, if the ignition zone is at stage 6, the process proceeds to step 24, where the ignition counter is started, the execution of this interrupt processing program is ended, and the process returns to the main control program. The content of the ignition counter at this time is the value set in step 23, and ignition is performed in stage 6.

If the determination result in step 25 is affirmative (0'er), that is, if the current stage is stage 6 but the ignition zone is stage 5, ignition has already been performed in stage 5, so this Ends execution of the interrupt processing program and returns to the main control program.

Figure 6 shows step 19 and step 2 shown in Figure 51\1.
Ignition counter value setter 11iF' executed in step 3
12 is a flowchart illustrating details 1 of i.

In Stella Two 191, the time ratio γ ("""s'/"s'" of stages 6 and 5 during the previous ignition shown in Fig. 4)
, ) is rewarded - a fire breaks out. Next, proceed to step 192 VC and calculate VIT5X at stage 5, which is set as the ignition zone. This time 1゛,X cannot be measured before ignition. Therefore, first, the time T3 of the stage before stage 5, which is the second stage before stage 6 in this embodiment, is measured. Next, the time ratio between stages 6 and 5 during the previous ignition is “5’/
Assuming that "s' (= γ) is the same as the time ratio between stages 6 and 5 during the current ignition, "5/Ts," h1 is added to the measured time T of stage 6. The value multiplied by the ratio γ is determined, and this value is set as the time T, x of stage 5 at the time of the current ignition. pljchi, T5x””T,
Let xγ−T3×(T5′/Ts′).

Next, proceeding to step 196, a value Tig corresponding to the ignition angle θLg calculated in step 5 is obtained, and this value Ttg5
t Set to Q fire counter (step 194).

For example, when the ignition angle θ is at the position of TDC collar r140 degrees, this Tig5 value is the starting position of stage 5 (TD
This is the candy (7th U9..1) corresponding to the time from 60 degrees before TDC to 0 degrees in the 4th layer before TDC, that is, 20 degrees.

This Ti! The IB value is obtained by interpolating the time T of stage 5 (corresponding to a rotation angle of 30 degrees of the crankshaft) by interpolating η - for example, by calculating proportionality. For example, in the above example, Ti, q, -T
, ×2Q-. However, the actual calculation is based on the above-mentioned reason.
Use x.

Similarly, step 23 is executed, and the ignition angle θL when the ignition zone is at stage 6! The value T corresponding to I. (Fig. 7) is obtained. In the execution of this step 23, the 1 of T, / and T6' measured during the previous ignition shown in FIG.
Calculate the ratio γ between stages 9 and 4 (calculate 11 and calculate the 6th
The steps are carried out in the same manner as in step 19 according to the step numbers shown in parentheses in the flowchart of the figure.

1' When the t9 value is calculated, this TLg value is then set in the ignition counter (step 194 or step 234).
).

In this way, when calculating the Tig value by interpolation, when the ignition zone is the target of interpolation q! l T or T
T for 6. Since it is predicted and determined from the time change of the previous stage between the four signals, ignition can be performed at the optimum ignition timing even when the engine speed fluctuates, for example, when the engine speed is increased or decreased.

In the above-mentioned example, the present invention was applied to ignition timing control, but the present invention is not limited to this, and the engine operation is controlled depending on the rotation angle of the crankshaft. The present invention can also be applied to a method, for example, a method in which fuel injection timing is controlled based on the crank angle.

jJAs explained above, according to the present invention, the first signal generated every time the crankshaft of the engine rotates by a predetermined angle, and the second signals generated a plurality of times between the first signals are controlled by the microprocessor. In an ignition timing control method that performs interpolation calculation processing and controls the ignition timing of an internal combustion engine based on the processing, the time ratio between the second signals is calculated and the time ratio between the first signals generated next time is calculated. Since the cycle of the second signal is corrected by multiplying the time ratio, even when the engine speed fluctuates, the ignition can be performed at an ignition angle that matches the operating condition of the engine. can do.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a photoelectric rotation angle detector, Fig. 2 is a block diagram illustrating the entire electronic ignition timing control device to which the present invention is applied, and Fig. 3 shows the electronic control unit of Fig. 2. Block diagram showing the internal configuration, Fig. 4 1(α) to (d)
) is a timing chart explaining the operation of the slave control unit in the evening of FIG. 2, FIG. 7 is a detailed flowchart of steps 19 and 26, and FIG. 7 is a timing chart of 1° and 4 signals during engine acceleration. -・ 10...Electronic control unit, 11...PB
Sesen, 12.13... Rotation angle detector, 14... Ignition circuit, 15... Ignition coil, 102... C7)U
. Applicant Honda Motor Co., Ltd. Agent Patent Attorney Toshihiko Watanabe Figure 5 - 417 - Beginning 6

Claims (1)

[Claims] 1. A microprocessor performs interpolation calculation processing on a first signal generated every time the crankshaft of the Ensica rotates by a predetermined angle and a plurality of second signals generated between the first signals;
In the ignition timing control method for controlling the ignition timing of an internal combustion engine based on the processing, the time ratio between the second signals is fully calculated, and the period of the second signal generated between the next first signals is set to the period of the second signal. An ignition timing control method characterized by total multiplication correction of the ratio.