JPH01155076A - Engine controller - Google Patents

Abstract

PURPOSE:To make any drop in accelerating responsiveness and accelerated feeling at the time of sudden acceleration preventable by limiting control over output torque when a sudden accelerating state is detected. CONSTITUTION:At a control unit 23, ignition timing is compensated for timing delay so as to cause output torque of an engine E to become an inverse characteristic to a variation characteristic of engine speed at acceleration, thereby controlling an accelerating vibration. Hereat, when throttle opening to be detected by a throttle opening sensor 15 is more than the specified value, an accelerating requirement is strong enough so that a control gain of ignition timing delay compensation is reduced to linearity according to an increase in the throttle opening. With this constitution, any drop in accelerating responsiveness and accelerated feeling at the time of sudden acceleration is thus preventable while aiming at an accelerating vibration reduction at acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine control device, and particularly to a control device for suppressing vibrations during acceleration of a vehicle engine.

[Prior art]

Conventionally, when a relatively sudden accelerator operation is performed, particularly in a vehicle in which power is transmitted without going through a fluid coupling, the vehicle causes a jerky longitudinal vibration of the vehicle body. This is because the engine torque change is the source of the earthquake, which is amplified by the resonance of the drive system. Countermeasures have been taken to address this problem, such as controlling the engine torque and optimizing the rigidity of the drive system, but these are not sufficient. Furthermore, recently, a vibration suppression control device has been proposed that actively changes engine torque to quickly converge vibrations.

For example, Japanese Patent Laid-Open No. 58-48738 discloses that when the vehicle speed suddenly changes, the engine output torque is controlled by ignition timing control so that the characteristic is inverse to the fluctuation characteristic of the engine speed caused by the sudden change in vehicle speed. A vibration suppression control device for a vehicle is described.

[Problem that the invention seeks to solve]

According to the vibration suppression control device described in the above publication, it is possible to reliably reduce acceleration vibrations during acceleration. However, when controlling the engine output torque so that it has an inverse characteristic to the change characteristics of the engine speed, it is not possible to increase the output torque, so by retarding the ignition timing, the output torque can be decreased. There is a problem in that the acceleration response during corner and acceleration decreases, leading to a decrease in acceleration feeling.

[Means for solving problems]

An engine control device according to the present invention is an engine control device that controls the output torque of the engine so as to have a characteristic opposite to the variation characteristic of the engine output torque during acceleration, when a sudden acceleration state is detected. In this case, the control of the output torque is limited.

[Effect]

In the engine control device according to the present invention, in order to suppress acceleration vibration, the engine output torque is controlled so as to have a characteristic opposite to the fluctuation characteristic of the engine output torque during acceleration, but when the engine is in a sudden acceleration state, Since the control of the output torque is limited, acceleration responsiveness during sudden acceleration is not impaired.

(Effects of the Invention) As explained above, the engine control device according to the present invention is capable of reducing acceleration vibrations during acceleration while preventing deterioration of acceleration response and acceleration feeling during sudden acceleration. I can do it.

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

This embodiment is a case in which the present invention is applied to a vertical four-cylinder engine for an automobile, and FIG. 1 shows the overall configuration of the engine and its control device.

As shown in FIG. 1, the engine E has a combustion chamber 4 formed by a cylinder block 1, a cylinder head 2, and a piston 3, an intake valve 6 that opens and closes an intake boat 5, and an exhaust valve that opens and closes an exhaust port 7. 8, an intake passage 9 is connected to the intake boat 5, and an exhaust passage 1 is connected to the exhaust port 7.
o is connected, an injector 11 for injecting fuel toward the intake boat 5 is installed in the downstream part of the intake passage 9, and a spark plug 12 facing the combustion chamber 4 is provided in the cylinder head 2. An igniter 13 is provided for outputting an ignition drive signal to.

An air cleaner is provided at the upstream end of the intake passage 9,
A throttle valve 14 is installed in the middle of the intake passage 9,
The throttle valve 14 is operatively connected to an accelerator pedal.

Sensors for obtaining data necessary for controlling the engine E include a throttle opening sensor 15 that is connected to the throttle valve 14 and detects the opening of the throttle valve 14 with a potentiometer; An intake negative pressure sensor 16 that detects the intake negative pressure in the intake passage 9 on the downstream side, a water temperature sensor 17 that detects the cooling water temperature in the water jacket of the cylinder block 1, and a a crank angle sensor 20 that detects the rotation angle of the crankshaft 18 in 5° divisions, for example, and a neutral switch 21 that is provided in conjunction with a shift lever that switches the transmission and is turned on when the transmission is in the neutral state. neutral SW), and a clutch switch 22 (clutch sW) that is provided in conjunction with the clutch beta and turns ON when the clutch is disengaged.

A control unit 23 is provided that controls the engine E based on detection signals from the sensors, and controls the engine E based on the throttle opening signal from the throttle opening sensor 15, the intake negative pressure signal from the intake negative pressure sensor 16, and the water temperature. sensor 17
A water temperature signal from the engine, a crank angle signal from the crank angle sensor 20, a switch signal from the neutral SW 21, and a switch signal from the clutch 5W22 are input to the control unit 23, respectively.

The control unit 23 includes a waveform shaping circuit that shapes the waveform of the crank angle signal, and an A/D converter that A/D converts the throttle opening signal, intake negative pressure signal, and water temperature signal.
An input interface, a microcomputer including a CPU (central processing unit W), a ROM (read only memory), and a RAM (random access memory), a drive circuit for the igniter 13, and an injector 1.
It is equipped with a drive circuit for 1.

The above-mentioned ROM contains a control program for vibration suppression control (including ignition timing control), a control program for fuel control, and a map and control program for normal ignition timing IgTo using engine speed and intake negative pressure as parameters. Necessary tables and the like are input and stored, and the RAM is provided with temporary storage memory (memory, flags, counters, etc.) necessary for controlling them.

By the way, the engine control device of this embodiment retards the ignition timing so that the engine output torque has an inverse characteristic to the variation characteristic of the engine rotational speed during acceleration, and suppresses acceleration vibration. During acceleration, the retard angle correction is limited to ensure acceleration responsiveness.

Hereinafter, the routine of the acceleration vibration suppression control will be explained based on the flowcharts of FIGS. 2(a) to (d) and FIGS. 3 to 5. In addition, St (+=1.2.3,...
・) indicates each step.

Figure 2 (a) shows a 5ms ec routine which is the main routine.
A calculation of JIIgTo is performed.

This normal ignition timing 1gTo is the engine rotation speed N obtained by the interrupt processing routine shown in FIG. 2(C). and the intake negative pressure obtained from the intake negative pressure sensor 16 from a map in the ROM. Next, in S2, the throttle opening TV, water temperature WT, neutral SW21, and clutch SW
The switch signal from 22 is read, and then it is determined at 33 whether the transmission is in a neutral state or the clutch is in a disengaged state. If the determination result is No and the vehicle is in a running state, the process moves to S4, and again is determined. When the result is Yes, the process moves to S17, and in S4 it is determined whether the water temperature WT is less than the predetermined value WTo. When WT≧WTO (when the engine is warmed up), the process moves to S5, and if WT<WTo. In some cases, the process moves to S17.

When WT≧WTo, the current throttle opening T in S5
The amount of change △TV in the throttle opening TV is calculated by subtracting the previous throttle opening TVo from V, and then in 86 the previous throttle opening TVo is updated with the current throttle opening TV. At 87, the above change amount △TV
It is determined whether or not is less than a predetermined value (not accelerating). If accelerating, the process moves to S8, and if not accelerating, S
Move to 13. During acceleration, the acceleration vibration control flag FACC is set in S8, and then in 89 the RAM
A gain counter GC provided in the memory is set to a set value GCo. For example, as shown in FIG. 3, the gain counter GC is intended to gradually reduce the control gain of the acceleration vibration suppression control after the acceleration starts, in view of the fact that the acceleration vibration becomes larger the earlier the acceleration starts.

Next, the SIO calculates an ignition timing correction amount ΔIgT for retarding the ignition timing in order to suppress acceleration vibration. Normally, the ignition timing 1gTo is set to the advanced side so as to obtain the best torque, so by delaying the ignition timing, the output torque can be reduced by about 30% at most. A subroutine for calculating the ignition timing correction amount ΔIgT is shown in FIG. 2(b).

That is, the control gain correction coefficient KGA corresponding to the throttle opening T■ detected in S20 is the throttle opening TV
The relationship between the control gain correction coefficient KGA and the control gain correction coefficient KGA is calculated from a ROM table set as shown in FIG. As shown in Fig. 4, when the throttle opening TV is approximately 30% or less, the control gain correction coefficient KG is adjusted according to the increase in the throttle opening TV.
A increases linearly, and the throttle opening TV becomes approximately 30 to 6.
In the range of 0%, the control gain correction coefficient KGA is 1.0, and when the throttle opening TV is approximately 60% or more, the control gain correction coefficient KGA is set to decrease linearly as the throttle opening TV increases. ing. That is, when the throttle opening TV is relatively small and the acceleration vibration is weak, the control gain is set to a small value of 6, and as the throttle opening TV increases, the control gain is increased. In the range of ~60%, acceleration vibration becomes significant, so the control gain KG should be made as large as possible, and when the throttle opening TV is about 60% or more, the acceleration request is strong, so to ensure acceleration response, the control gain should be set to The acceleration vibration suppression control is limited in such a way that it linearly decreases as the degree TV increases.

Next, at 821, the control gain KG is calculated by multiplying the control gain correction coefficient KGA by the gain counter GC, and then at 322, the engine rotation speed N during the latest 200 rnsec is calculated. The amount of change ΔN11200 is the engine speed NQ□ 200 m5ec before the current engine speed N8. Calculated by subtracting 0. Next 3
23, engine rotation speed N every 5m5ec during the past 200m5ec.

data will be updated. In addition, as described later, the engine rotation speed N. Because the data is calculated by reading the crank angle signal under certain conditions every 45° BTDC (every half rotation of the crankshaft) for each cylinder, the data is based on the past engine rotation speed N in S23, ZOO% Na 195, NOI 'l. ...
has the same value for several pairs.

Next, at 324, the ignition timing correction amount △IgT is
=, it is calculated by the formula: X (ΔN8−ΔN8□..). Here, the above △NGzoo = (N,, -N, 2
00), the above N,,□oo are updated sequentially as in S23, so ΔN8□oo is the latest 200m5
This corresponds to the moving average of S8 between e and c. The above ΔN is calculated by the interrupt processing routine shown in FIG.
(equivalent to) engine rotational speed N. It represents the amount of change in . That is, (ΔN, -200 to 8 No.) represents the amount of change in the current engine speed NQ with respect to the latest 200m5ec moving average, and this (ΔN, -
Considering that an acceleration proportional to ΔN8zoo) acts on the vehicle body, and considering that the engine output torque decreases approximately in proportion to the amount of retardation of the ignition timing, the ignition timing correction amount ΔIgT is set as above. This is how you set it up. Next, in step 325, it is determined whether △IgT is larger than the set value △■gTMax (for example, 5°), and if Yes, in S26, △IgT=△I g TM-X is set, and then the process returns to the main routine. If NO, S27
, ΔIgT is the set value ΔIgT, . (For example, 1
°), and if Yes, S28
In △IgT - △IgT yo8. ．． After that, the process returns to the main routine, and if the answer is No, the process directly returns to the main routine.

When the ignition timing correction amount ΔIgT is calculated in S10 by the subroutines 320 to 328 above, the final ignition timing IgT is calculated in Sll using the formula IgT=IgTo+ΔIgT, and then in 312 the ignition interrupt After performing timing calculation, return to Sl. The above calculation of the ignition interrupt timing is a calculation of converting the above final ignition timing IgT into real time, and the obtained timing is CP
The time signal is received from the free-running counter attached to the U and set in the first counter, which functions similarly to a timer, and the second (d) output conveyor interrupt is executed at the interrupt timing obtained above. .

On the other hand, as a result of the determination in S7, if the rate of change ΔTV of the throttle opening TV is less than the predetermined value and the acceleration is not in progress, S13
At 313, acceleration vibration control is in progress (flag FAcc
=1), and if No, proceed to S17,
When YES, the process proceeds to S14, where the gain counter GC is decremented by a predetermined value ΔG, and then, at 315, it is determined whether the acceleration vibration control has ended (gain counter GC=O), and when No, the process proceeds to SIO. If Yes, the process moves to S16, where the acceleration vibration control flag FAce is reset, and then, at 317, the ignition timing correction amount ΔIgT
is set to zero and then moves to Sll.

Figure 2 (C) shows the crank angle BT based on the crank angle signal.
This is a routine that is executed by interrupt processing every 45° DC. When the interrupt processing starts, the time TBDC at the crank angle BTI)C45° is read from the free running counter in S30, and then TDC is executed in 331. The period 'r'rnc is calculated by subtracting the previous time TBTDCO from the current time T, a, c, but since it is a 4-cylinder engine, the above TDC period TTDC corresponds to the period in which the crankshaft makes half a revolution. It is.

Next, at 332, the previous time T IITD. 0 is the current time TETD. The engine speed is updated at 333, and then the engine speed N is updated at 333. is N. -30/TTDC, and then the engine speed N at 334. The amount of change ΔN.

is obtained by subtracting the previous engine speed N eo from the current engine speed N8, and then 335
The previous engine speed N GO is the current engine speed N. is updated, and then returns to the main routine.

FIG. 2(d) is a routine that outputs an ignition command signal (energization cut command) to the igniter by the output conveyor interrupt processing routine, and this routine is executed every time the counter value of the first counter reaches the set value. and S4
3, the second counter (where the next energization start time is set)
However, it is started every time the counter value of the first counter (which has the same function as the first counter) reaches the set value. When this interrupt processing routine is started, it is determined in S40 whether or not the primary coil of the igniter 13 is currently energized, and if No, S4
After starting the energization in Step 1, the process returns to the main routine, and when the answer is Yes, the igniter 13 is turned on in Step S42.
An energization cut command is output to cause the spark plug to ignite, and then, at step 343, the next energization start time is set in the second counter, and the process returns to the main routine. That is, when the count value of the second counter reaches the set value, an interrupt is executed and energization is started, and when the count value of the first counter reaches the set value, the interrupt is executed and ignition is performed. However, since a predetermined minute time is required until a predetermined ignition energy is accumulated in the primary coil of the igniter 13, the control is performed as described above.

The above-mentioned acceleration vibration suppression control will be explained with reference to FIG. 5. When the accelerator pedal is depressed to increase the throttle opening while the car is running, the engine speed change amount ΔN8 and the engine speed change amount ΔN8 and (ΔN, -
Go to 8N8. . ) becomes as shown, (to NO-to N,
□. . ) will act on the vehicle body. In order to suppress the vehicle body vibration caused by the above-mentioned rotation speed fluctuation,
As shown in the figure, the ignition timing is retarded and the output torque of the engine E is reduced during the period when (ΔN, -ΔNe□..)>0. Note that Δt in V is a delay time due to a detection delay.

In addition, in the routine of FIG. 2(b) above, 8N020
Instead of finding 11, N11Zoo % N.

+95,...NQ5, actual moving average N8□. .

The ignition timing correction amount ΔIgT may be determined by using the equation ΔI gT=, X (N, −N, maaj).

In the acceleration vibration suppression control of the above embodiment, the gain counter G
Since C is provided so that the control gain becomes larger in the early stages of acceleration, it is possible to effectively suppress the rise of acceleration vibration. In addition, since the characteristics of the control gain correction coefficient KGA are set to the characteristics shown in Fig. 4, acceleration vibration suppression control is limited and the ignition timing is retarded while the throttle opening degree TV is relatively small and acceleration vibration hardly occurs. Loss associated with correction can be kept low, and when the throttle opening degree TV is large and acceleration demand is strong, acceleration vibration suppression control can be restricted to prevent deterioration of acceleration feeling.

In the above embodiment, the output torque is lowered and acceleration vibration is suppressed by retarding the ignition timing.
The air-fuel ratio may be corrected to the lean side to lower the output torque and suppress acceleration vibration.

Furthermore, in the case of an engine in which auxiliary equipment such as an alternator, EGR amount, and throttle valve are electrically operated, a throttle valve or the like may be used as a means for changing the output torque to suppress acceleration vibration. Further, in the above embodiment, sudden acceleration is determined based on the amount of change ATV in the throttle opening degree TV, but when the throttle opening degree TV becomes larger than a set value, it is determined that there is an acceleration. Alternatively, the throttle valve 14 and the accelerator pedal may be mechanically connected (in the case of this embodiment).
The amount of depression of the accelerator pedal may be used instead of the throttle opening TV, or the intake negative pressure may be used instead of the throttle opening TV (however, in this case, correction based on the engine speed is required. be).

In the previous embodiment, changes in the engine speed are detected as means for detecting vibrations in the vehicle body, but there are other means to detect vibrations in the vehicle body, such as vehicle speed, wheel speed changes, drive shaft torsion, engine displacement, etc. You can use any of them.

B. In the above embodiment, the control gain is made variable as a means for changing the control amount of the engine torque, but it is also possible to make the limit on the amount of control a variable or to make the control time variable.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall configuration diagram of an engine and its control device, FIG. 2(a) is a flowchart of the main routine, and FIG. 2(b) is an ignition timing correction amount calculation. Flowchart of the subroutine, Figure 2 (C)
2(d) is a flowchart of an interrupt processing routine for calculating engine speed, etc., FIG. 2(d) is a flowchart of an output conveyor interrupt processing routine for ignition control, FIG. 3 is an explanatory diagram of a control gain counter, FIG. 4 is a characteristic diagram of the control gain correction coefficient, and FIG. 5 is a time chart of changes in engine speed, etc. E... Engine, 14... Throttle valve, 15...
Throttle opening sensor, 16... Intake negative pressure sensor,
20... Crank angle sensor, 23... Control unit. % otsu\su \suno's 0, + to I? /)■00's (1) C/)'s
(Dimensions of power ward [to M entry ○ O dimension

Claims (1)

[Claims] (1) In an engine control device that controls the engine output torque so that it has an inverse characteristic to the variation characteristic of the engine output torque during acceleration, when a sudden acceleration state is detected, the output torque An engine control device characterized by being configured to limit control.