JPH01193065A - Control device for engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine control device, and particularly to a vehicle body fMw.
The present invention relates to an engine control device that aims to reduce J.

(Prior Art) Conventionally, for example, in a vehicle where power is transmitted without going through a fluid coupling, when a comparatively unnatural accelerator operation is performed,
The vehicle's body shook and vibrated back and forth. This is because the engine torque change is the source of the earthquake, which is amplified by the resonance of the drive system. In response to this, measures have been taken to limit changes in engine torque and optimize the rigidity of the drive system, but these are not sufficient.

Recently, a proposal has been proposed to actively change the engine torque to quickly settle vibrations (Japanese Patent Laid-Open No. 58-487
No. 38, etc.), and this Japanese Patent Application Laid-Open No. 58-48738 detects a change in engine speed and makes the engine torque have an inverse characteristic with respect to the change in engine speed. Specifically, the output of the engine speed sensor is passed through a low-pass filter that extracts the torsional vibration frequency component of the drive system, thereby detecting rotational fluctuations. If the value exceeds a threshold value, the ignition advance angle is controlled in accordance with the rotational fluctuation.

In addition, we took this Japanese Patent Application Publication No. 58-48738 one step further,
There is also a proposed technology that attempts to actively change engine torque in the same way. In other words, the ideal engine torque control to quickly damp vehicle body vibrations is to reduce the engine torque when the vehicle body longitudinal acceleration is positive, and increase the engine torque when it is negative. When damping vehicle body vibration using changes,
Theoretically, it is sufficient to change the engine torque by delaying the phase of the engine rotational speed change by 1/4 period with respect to the drive system resonance period.

(Problem to be Solved by the Invention) However, the inventors of the present case have found that because the above technology is based on an ideal engine model, in reality, the actual torque control starting point is not accurate due to various control delay times. We have found a problem in that the process is not performed after a delay of 174 cycles.

The above-mentioned control delay time is caused by, for example, the following points.

Control circuits actually used for engine control (mainly,
(a digital microcomputer is used), only temporally discrete data can be obtained as external data.For example, engine speed, etc. is calculated from the period of a pulse signal from a sensor installed on the crankshaft. However, this calculation result itself includes a time delay element, and is not the engine speed at any given moment (real time).Also, the rotation speed sensor output is usually accompanied by noise; In order to cancel the error component, the engine speed determined above is averaged over several revolutions, and this average value is taken as the engine speed at that point. However, it is clear that this average value is actually delayed in time due to the time division control of the digital computer.

Therefore, even if an attempt is made to change the engine torque by delaying 1/4 period with respect to the engine rotation speed by relying on engine rotation speed fluctuations as in the above-mentioned conventional technology, the engine rotation speed itself depends on the engine rotation speed. Therefore, in terms of control, torque control was performed based on incorrect data, leading to a situation where the engine vibration described above was not reduced.

Furthermore, considering that the control microcomputer performs engine control in synchronization with the engine speed, the control delay time varies depending on the engine speed. Therefore, if the engine speed fluctuation is uniformly delayed by 1/4 period without considering the engine speed as in the prior art, etc., then in a certain range of engine speed, this 1/4 period The control delay time becomes longer than the delay time for four cycles, resulting in insufficient vibration suppression or even aggravation of vibration.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an engine control device that suppresses vehicle body vibration based on fluctuations in engine speed, and which suppresses vehicle body vibration based on fluctuations in engine speed. This makes it possible to reliably suppress engine vibrations, which was actually impossible in the past.

Furthermore, the present invention proposes an engine control device that can accurately and reliably suppress vibrations even at low engine speeds where the control delay time is large.

[Means and operations for solving the problems] As shown in FIG. 1, the configuration of the present invention for achieving the above-mentioned problems includes 341 calculating means for intermittently calculating the fluctuation value of the engine speed. , a second calculation means for calculating the vibration period of the vehicle body vibration, a calculation means of 343 for calculating a control delay time when controlling the engine torque based on the engine rotation speed variation calculated intermittently; 1/ of the vibration period
The present invention is characterized in that vehicle body vibration during acceleration is suppressed by providing a torque control means for controlling the output torque of the engine with a delay of a time obtained by subtracting the control delay time from the time of 4.

(Example) The present invention will be described in detail below with reference to the accompanying drawings. In this embodiment, the value of the difference between engine speed fluctuation and its average value is used as the control amount for torque control, and this control amount is (vibration period/4-control).

The idea is to perform torque control by shifting the torque by a delay time (delay time). In addition, there are two modified examples of this embodiment, and in the second modified example, in view of the fact that torque control may not be possible in the low engine speed range in this embodiment, such torque control is not possible. Special measures have been taken to control this to minimize the chances of it running out.

(Engine Vibration Suppression System) The overall configuration of an engine vibration suppression system that has been applied to each of the embodiments according to the present embodiment will be described using FIGS. 4 to 6.

Figure 4 is an overall view of a four-cylinder fuel injection engine.
Parts that are particularly relevant to this embodiment include an air flow meter 1, a throttle valve 2, an injector 5, a temperature sensor 8 that detects the cooling water temperature, a spark plug 9, an ignition coil 101, a distributor 11, an igniter 18, and a sensor that detects the intake pipe internal pressure B. a boost pressure sensor 19 for controlling the engine, an engine controller (ECU) 20 for controlling the entire engine, an opening sensor 22 for detecting the opening (TVO) of the throttle valve 2, an opening sensor 23 for detecting the accelerator opening, The position sensor 24 and the like detect the gear position GP of a transmission (not shown). Note that this gear position sensor 24 is not used in the second embodiment in view of its secondary purpose of reducing the number of neutral switches and the like.

The intake air is measured by the air flow meter 1 to determine the intake air amount Q.
1 was measured. This intake air is guided into the combustion chamber of the engine body 6 through the surge tank 3 while its amount is adjusted by the throttle valve 2 . Gasoline is injected from the injector 5. This injection time is defined by the pulse signal τ output from the ECU 20. The combusted air-fuel mixture passes through the exhaust manifold and the catalytic converter 17 and is released into the atmosphere.

A crank angle signal CA is output from the crank angle sensor 12 of the distributor 11, and a cylinder signal CY is output from the cylinder sensor 13 to the ECU 20 every time the engine rotates, and are used to identify the cylinder and synchronize the engine rotation.

The igniter 18 is the same as the well-known one, and cuts the negative current at the rise of the ignition timing signal IQ.
The energization is restarted after a certain period of time after the cut.

FIG. 5 is a diagram showing the internal configuration of the ECU 20 and connections between it and various sensors and the like. In the figure, the crank angle signal CA is input to an interrupt terminal of a CPU 34 via a waveform shaping circuit 3o. This signal CA is a rotation angle signal 45 degrees before TDC, expressed as 45 degrees BTDC, and CP
When input to U34, an interrupt routine is called and, for example, calculation of the engine rotational speed is performed. The signal CV from the cylinder sensor 13 is sent to the digital buffer 3
2. is input to the CPU 34 via the input port 33,
Used for cylinder identification.

The analog signals such as boost pressure B and intake air amount Q1 pass through the analog buffer 33 and are converted into digital values by the A/D converter 46, and the converted digital values are sent to the CPU.
34. 36 to 40 are programmable timers (PTM), and the data set in them are ignition timing IG, 4 for the four cylinders, respectively from the top.
There are four fuel injection pulses τl to τ4. These PTMs
The clock signal is a free counting counter (FRC).
) 42.

The ROM 43 stores programs for control procedures such as flowcharts described later. The RAM 42 is used to temporarily store intermediate data necessary for control.

FIG. 6 is a functional block diagram of engine control performed by the ECU 20. The EGI section, which is a block that calculates the fuel injection amount τ from the injector 5, is well known. The ESA section that controls ignition timing is the central part that performs torque control to suppress vehicle body vibration.

<Principle of torque control> 552 people 1 FIG. 2 shows an overview of torque control in this embodiment.

This will be explained using FIGS. 3 and 7. Figure 2 shows macroscopically the change in engine speed N when the accelerator is depressed and throttle valve 2 opens (TVO is throttle opening), and Figure 3 shows the change in engine speed N. This is a microscopic representation of N, etc.

As shown in Fig. 3(b), the cycle of vehicle body vibration wJ (represented by acceleration G) generally does not change unless the drive system conditions such as the gear ratio change. Although there are changes, the vibration period does not change depending on the type of vehicle or the elapsed time of vibration. Also,
When vehicle body vibration occurs, torsion occurs in the drive system, which is manifested in fluctuations in rotation N. In other words, vehicle body vibration is indirectly caused by fluctuation ΔN in engine speed N.
((e) in Figure 3). In other words, since the car body vibration is a periodic fluctuation, the rotational speed fluctuation Δ
N has the same period as the vehicle body vibration, apart from the amplitude 0 phase difference (Fig. 3 (e)). Therefore, ΔN is the most appropriate information for vibration suppression, and therefore, this information is processed appropriately. Then, it's time to ignite! . is converted into an advance/retard amount ΔIG to perform torque control for vibration suppression.

The characteristics of engine torque change control should be such that it is performed in a phase opposite to the vibration cycle of the vehicle body.
When the vibration acceleration G is in a phase where it gradually increases, the torque is controlled to gradually decrease, and when the vibration acceleration G gradually decreases, the output torque is Vibration can be more effectively suppressed by controlling it so that it gradually increases (Fig. 3 (f)). In other words, when the vibration acceleration mentioned above is in the phase where it gradually increases, the torque is controlled so that it gradually decreases, and the vibration acceleration increases. In order to control the output torque so that it gradually increases when it gradually decreases, it is necessary to adjust the engine speed fluctuation Δ
It is advantageous in terms of phase to use the amount obtained by delaying the characteristic of N by 1/4 period (FIG. 3(e)).

That is, the period of torque control is the period T36° of ΔN (=
(vibration period), and the phase difference corresponds to the rotational speed fluctuation ΔN
For, T9゜・=phase difference=vibration period/4...(1)
The phase difference Tg is such that .・It is good to have

By the way, since the engine speed is basically in the stop-up direction during acceleration, it is necessary to detect only the change thereof. Therefore, in order to perform torque control with high accuracy, the DC component ΔN is subtracted from the engine rotational speed fluctuation ΔN. That is, in order to control the torque to gradually decrease when the vibration acceleration is in the phase of gradual increase, and to control the output torque to gradually increase when the vibration acceleration gradually decreases, (ΔN
-ΔN) is used by delaying the characteristic by 1/4 period.

In this embodiment, torque control is realized by ignition timing control, so in order to realize the above phase control, the ignition timing correction amount, Δ1o1=aX(ΔNo −ΔN), is calculated for each control cycle of the engine. is calculated, indexed and stored in memory, that is, Δto obtained in this way is calculated over the past n times, and Δ! . ”(1).

ΔIa"(2).

ΔIQ"(n) is stored in the memory. The ignition timing correction amount Δto(m) necessary to suppress vibration at a certain point is ΔIa(m) = Ka X (ΔN0-ΔN)...
(2) Assuming that m is the index number for obtaining ΔI (I) obtained in the past control cycle.

The above is the basic method of torque control, but in this embodiment, in order to further improve control accuracy, the following concept of "control delay time" is introduced, and this "control delay time" This is to perform torque control that advances (returns) the phase by the amount of time. That is, the above m is defined as where: Control delay time - The phase difference between the actual rotational speed fluctuation and the calculated (detected) ΔN. This "control delay time" will be described later. For example, engine rotation speed calculation etc. is performed using TDC (TOPDEATH).
This occurs unavoidably because it is performed every time (CENTER). In other words, T. equal to 1/4 vibration period. * becomes a constant value once the gear is determined, but the above-mentioned "control delay time" includes the detection delay of the engine rotation speed and the delay from ignition until the engine torque changes. In other words, even if the engine speed fluctuation ΔN is detected, the detected (calculated) ΔN lags behind the engine speed fluctuation caused by the car body vibration G that is currently occurring. ΔN corresponds to the actual rotational speed fluctuation ΔN advanced by the “control delay time”. Therefore, it is necessary to subtract the "control delay time" from the "vibration period/4" and advance the phase of the torque control by the "control delay time" from the "vibration period/4".

Now, let's specifically find this "control delay time." For torque control, it is necessary to calculate the engine speed N, ΔN, and ΔN.

If the engine speed N is calculated every TDC cycle, the "control delay time" calculated by the engine speed N is 0.57DC.For the same reason, the "control delay time" calculated by the engine speed fluctuation ΔN is 0.57DC.
The "control delay time" is 0.57DC, and if the averaging for the rotational speed fluctuation average value ΔN is a moving average of, for example, 2 revolutions (i.e., 4TI) C), the "control delay time" by this average value calculation is The "delay time" is 1.57DC.Generally, in the case of a four-cylinder engine, the "control delay time" when taking an n-rotation moving average is (0,5+(n-1))TDC.Also, The "delay" from ignition to actual torque production is 0.57 DC, and this "delay" is dependent on the explosion burn rate.

To summarize the above delay times, the total "control delay time" up to the generation of torque at the time of calculation Q ignition is 3.0 TDC.If the ignition timing is advanced or retracted for torque control as described above, the 4-cylinder engine Since the engine ignites once every two revolutions, the control delay time JTCR per engine revolution is (3).

In this example, △ra“, which was obtained in the past and stored
From among them, the past one by the delay time TR TR=T90·-Tc++(ms)"" (4) is extracted and used. By the way, in general engine control using a digital computer,
Since the control amount is stored at regular time intervals, if this time interval is, for example, 5 ms as in the embodiment described later, the above-mentioned index m is as follows.

The previously stored ΔIa'' is used.

FIG. 9 is a table showing the resonant frequency of vibration at each gear position (GP) and the phase difference T90, T15, etc.

Now, since the ignition period becomes longer as the engine speed becomes lower, this "control delay time" becomes longer. Above delay time TR
Ha, TR! T90--TCR, and considering equation (3), in the engine rotational speed region where TR is negative at a certain gear position GP, that is, the control of this embodiment described above becomes impossible. This is because the fact that the delay time T□ is negative means that the current torque control is performed based on the future control amount (ΔN-ΔN). That is, in the engine rotational speed region where TR<0, even if torque control is performed, the torque does not actually change, or on the contrary, phenomena such as an increase in vehicle body vibration occur. Therefore, in this case, if only the control of the fourth embodiment described above is used, when % Tik approaches the negative T11°, that is, when the control delay time TCRJ approaches Tlao, when the vibration is in the positive direction. A hunting phenomenon occurs in which torque control is performed in the direction of increasing torque. Therefore, T CR-2T, . + Tl80'' = vibration period/2
The engine speed N MINI that is ・・・・・・(7), that is, ・・・・・・(8) is called the minimum controllable engine speed (basic). do. This N MINI changes depending on the gear position, as shown in FIG.

Also, the delay value TR becomes "O", that is,...
(9) The engine rotational speed Nl+1IN2 as follows will be referred to as the minimum engine rotational speed 1 that can be appropriately controlled. This is because the control of the above embodiment operates properly up to the range NMIN2. NMI82 also changes depending on the gear position, as shown in FIG.

Thus, with only the control of this embodiment, when the current engine speed N is equal to or lower than the minimum engine speed NMIN2 that can be properly controlled, it becomes necessary to take some measures. In particular, this is because this properly controllable minimum engine rotation speed NMINI is a rotation range that is often used. In other words, the first
In the region [I] shown in FIG. 0 (region of N kllN2 or more), appropriate vibration suppression control is possible.

For this reason, two modifications of the fourth embodiment for the low-speed operation region will be shown below.

From equation (5), in order for T and l to remain positive even when Tc11 increases, TCR should be decreased in the rotation range where TCR increases, or conversely T90. should be increased. The former control is a first modification, and the latter is a second modification. In addition, in the second modification, as long as the gear position is fixed, Tl1
Since o・ is fixed, instead of T QG−, “r, ,
We use T4io'=Tsao°+T90°, which is further delayed by one period from °.

<Details of the control of the embodiment> Five main forks 11 A detailed explanation of the control of this embodiment will be given according to Figs. 8A to 8D.
This is the main routine of the ESA section that is activated by an interrupt every s. FIG. 8B shows details of the calculation of the ignition timing correction amount Δ10 (step 5220) during the main routine. Figure 8C shows the crank angle signal C^ (-T
This is a routine for calculating the engine rotation speed and the engine rotation speed fluctuation ΔN, which is activated by an interruption of 45 degrees before DC). Also, Figure 8D shows the igniter 18
O CI (-OUTPUT COMPARE I
NTERRUPT) There is a routine.

First, the crank angle signal interrupt routine shown in FIG. 8C will be explained. When the crank rotates 45 degrees before TDC, the process advances to step 5260, where the current time 1 is read from FRC41.
．． In step 5262, TD is read from the interrupt time to calculated at the time of the previous interrupt.
The C period tyoc (time required for half a revolution of the crank) is ttoc "t+ -t.

Calculate according to In step 5264, the value of tl is saved in to for the next interrupt, and in step 8266, the engine rotation speed NO N t □ TDC is calculated. In step 8268, the previous BTDC4
From the engine speed NO which was 5 degrees before 5TDC, the current engine speed fluctuation ΔN 0) is calculated as ΔN'(0)-N-N
Obtain from o. Here, there is a delay of 0.57 DC. Step 5
270 calculates the 4-time moving average ΔN from ΔN''(1) to ΔN3) calculated and stored during the past 3 TDC hours, ΔN, ΔN0)◆ΔN1)◆ΔN2) To N responsibility 3
). This calculation results in a control delay time of 1.57 DC. In step 8272, the next Δ
For the calculation of R4, ΔNN13 to ΔN'' (3) are updated.

According to FIG. 8A, the main routine that is started every 5 ms will be explained. This main routine calculates the ignition timing correction amount ΔIa for suppressing vibration during normal ignition timing 1 ON and acceleration, and calculates the final ignition timing Ia. .

1(1”ION+Δ!.

Calculate. This IQ is calculated and output to the PTM 36 as a pulse width. Now, in step 5200, the normal ignition timing IOH is calculated according to normal conditions.
These normal conditions include, for example, the gasoline octane number and the amount of knocking. In step 5202, the throttle opening TVO, engine water temperature Tw, gear position GP, etc. are read, and in step 5204, the above N MINI is read.

In step 5206, the engine speed N and this N MI
It is compared with NI to determine whether or not the area is where hunting occurs. Hunting area 1 is processed in step 523
Proceed to step 4 to stop torque control. Step 8208
Then, if the engine water temperature TV is below the predetermined value TV,
Similarly, proceeding to step 5234, ΔI is set to "0". This is due to car body vibration and ignition timing I.
(This is because even if it is necessary to correct I, if the ignition timing is delayed by performing torque control when the water temperature is low, there is a possibility of a misfire.

Steps 8216 to 5214 are steps for detecting whether acceleration has started. Here, 'rvoo is
This is the throttle opening obtained last time (5ms interrupt). The start of acceleration is the throttle opening change Δ for 5ms.
The determination is made based on whether TVO is greater than or equal to a predetermined value ΔTV01. If acceleration has not started, ΔTVO≦ΔTVO.

Therefore, in step 8226, it is confirmed whether the acceleration vibration is being controlled by checking the set state of the 7-lag FAc. This FAC flag is set in step 3216, and after the acceleration start is detected, the throttle opening change ΔT
Even if VO is small, the vehicle is being accelerated for a certain period of time (Fig. 3 (d)), and during that time it is necessary to perform acceleration vibration control, so keep in mind that acceleration vibration control is in progress. It is in.

If this flag is not set, step 5234
, and set ΔI0 to "0".

When the start of acceleration is detected in step 5214, step 5
Step 216 sets the F"ac flag, and step 3218 sets the gain counter GC to an initial value Gc0. This initial value GCO is set to the flag FAC shown in FIG. 3(d). This is the time when acceleration vibration suppression control should be performed.This time is
In step 3220, ignition timing correction calculation is performed.

The ignition timing correction amount calculation routine will be explained with reference to FIG. 8B. The purpose of this subroutine is to calculate the ignition timing correction amount ΔI (I) according to the above formula and to perform limit control on this correction amount. First, step 524
0, the control gain is calculated by K, =l(o
a may be a constant of zero.

In step 5242, the ignition timing correction amount for the future is calculated according to ΔIo''=Ka Find the advanced index m.

In step 8246, the ignition timing correction amount ΔIG of this index m is searched in the memory to obtain the current vibration suppression. In step 5248, Δ
Update Ia map. Step 3254~Step 5
256 is ignition timing limit control.

In this way, by actively utilizing the control delay time that inevitably occurs due to the calculation of the engine rotation speed N1 rotation speed fluctuation ΔN, its average value ΔN, etc., for torque control to suppress vibration, vehicle body vibration can be optimized. It can be suppressed. In particular, it is possible to reliably prevent vibrations by setting N MINI at which hunting occurs in a low rotation range and by stopping torque control in a range below this range.

In addition, 1.5 of the above control delay time in the case of a 4-cylinder engine
TDC is the result of a 4-time moving average (step 5270), so it must be recalculated every time you use a 6-cylinder engine or increase or decrease the number of 6-time moving averages, but this control delay Time is a quantity that can all be calculated in advance.

East ± 1'' ■ 111 Kaki In the above equation, in order to reduce TCR so that Tll does not become negative, since TCR is mainly generated by the averaging operation when calculating the average engine rotation speed N, It is only necessary to change the moving average number of times depending on the value of the engine rotation speed. Thereby, the control delay time can be adjusted and the phase delay of engine torque change can be kept to a minimum. Specifically, in FIG. 10, N MIN
In the area of 2 lines or less, the control of the above embodiment is changed so that a moving average of 2 engine revolutions is used to calculate N, as in the control of the embodiment described above, and a moving average of 1 revolution of the engine is used in other cases. One rotation of the engine corresponds to 2 TDC periods, so for the 2-rotation moving average, sample 4 N, and use the following as in step 5270 of the previous embodiment.Similarly, for the 1-rotation moving average, 2 In the rotation moving average, the "control delay time" is 1.57 DC, same as the control in the fourth embodiment, but in the one rotation moving average, it is 0.
57DC, and the control delay time of the latter is shorter by ITDC. In this way, in the low rotation range, only ITDC and Tc
By shortening the number 11, the 10th
[! ■] Vibration suppression in the middle area becomes effective.

Since the TCR in the low rotation range is 0.5 TDC, as in the case of the above embodiment, the engine rotation speed 'NMIN3, which is
As shown in FIG.
Since the INS is lower than the old NMI, it can be seen that the controllable range has been significantly improved.

The control of the first modification will be explained in detail with reference to FIGS. 11A to 11C. This will be explained starting from Fig. ttC. Steps 3340 to 5348 will be omitted. In step 3350, N MINl corresponding to the gear position is read, and in step 5352, the current operating range N and N M are read.
Compare the size with gH2. In the region where N≧NMINI, the two-rotation driving average ΔFJ4 is calculated in step 8358.

In the region of N<Nmtsz, the one-rotation drive average ΔFJ2 is calculated.

Regarding the main routine of FIG. 11A, step 5204 of FIG. 8A of the previous embodiment. N MINl in step 5206 is NM
It only replaces ENS. This is because the minimum controllable rotational speed is changed to a low value with this modification. 1st
Figure 1B and Figure 8B, step 5244 and step 53
They differ only in 24. That is, aoooo・C m” (Tso”-) times! N, and as mentioned above, the engine speed is NMIH2
In the above range, the moving average of 4 data is taken, so it is C1.5, and in the low rotation range below N & 1IN2, the moving average of 2 data is taken, so -t, the control below 5326 is This is the same as in the previous embodiment.

1, 1, 1, 1, 2, 2, 3, 3, 3, 4, 5, 1, 2, 1, 1, 1, 1, 1, 1, 1,
Since the number of samples of the moving average for N is reduced to reduce the control delay time, T haze does not become significantly negative, and vibration can be suppressed reliably. Further, in the region of NMIN3 or lower, torque change control is stopped as in the above embodiment, so hunting does not occur.

If only the phase is considered, the smaller the number of moving averages, the better; however, in order to eliminate manufacturing errors of the type of crank angle sensor attached to the crank camshaft,
It is necessary to take a moving average of two engine revolutions. Therefore,
If possible, it is better to take a moving average of two engine revolutions.

11 Matarasa ■ Dansei 1 This second modification is in the operating region below the N MINm line in FIG. 10, and Tg in the formula of the above embodiment. T 480° is used instead of °. In this case, the cycle of car body vibration will not change.
Figure 10 [! In the eye area, it is possible to perform more appropriate torque control than the control in the above-mentioned embodiment.

In this second modification, the control flowchart of the embodiment described above is changed as shown in FIG. 12. That is, m is calculated in step 5244 of FIG. 8B, and m is calculated in step 540 of FIG.
0, check whether m is negative, and only if it is negative, in step 5402, m'' (re.°−11112−
) times 54 N and return to step 3246 of FIG. 8B.

In this case, since m does not become negative, reliable torque control is possible, and ride comfort in the low rotation range is improved. however,
T4. instead of T9°. .・Because it uses , it becomes difficult to suppress the first peak of vibration. Note that instead of shifting by a period of -, it is also possible to shift by half a period and reverse the sign of ΔIQ. That is, 60000·1.5 m = −(−T, .−□) times 54 N, and ΔIa=−ΔI (1” (m).

<Other Developments> Although the above-mentioned embodiments are intended to eliminate the control delay time inherent in digital computers, they can also be applied to analog computers since "detection delay" also exists in analog computers.

In the above three embodiments, the ignition timing was corrected as a means to change the engine torque, but in order to achieve the above effect, the air-fuel ratio, the load of auxiliary equipment such as the alternator, the amount of EGR, The throttle opening degree and the like may be corrected.

In addition to engine speed fluctuations, vehicle acceleration and wheel speed changes can be used to detect vehicle body vibration.

There is twisting of the drive shaft, engine displacement, etc.

In addition, the throttle opening TVO is used as an acceleration request detection means.
, In addition to the accelerator opening α, etc., the intake negative pressure B may be used. However, in this case, when the engine speed is low, the intake negative pressure B changes greatly even with a small accelerator opening. Therefore, it is necessary to correct the engine speed.

(Effects of the Invention) As explained above, according to the engine control device of the present invention, the control delay time such as the detection delay time or the ignition delay time that occurs in the control device is taken into account in the torque control. This makes it possible to reliably suppress engine vibrations, which was actually impossible.

In particular, the averaging time when calculating rotational speed fluctuations can be shortened in the low rotational speed range, or even -
By using control data with a period delay for torque control, vehicle body vibration can be reliably suppressed in the low rotation range.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the present invention in detail, Fig. 2 is a diagram showing the engine rotation speed N from the start of acceleration, and Fig. 3 is an example of vehicle body vibration and torque control for suppressing it. 4 is an overall block diagram of the engine system of the embodiment, FIG. 5 is a diagram showing the internal configuration of the engine control unit (ECU) of the embodiment, and FIG. 6 is a diagram of the embodiment. A functional block diagram of the engine control performed by the ECU. FIG. 7 is a diagram explaining how a control delay occurs in the embodiment. FIGS. 8A to 8D are a control flowchart according to the embodiment. FIG. 9 10 is a table summarizing the data used in the embodiment and its two modifications, FIG. 10 is a table summarizing the operating range of the embodiment and its two modifications, and FIGS. 11A to 11C are Flowchart showing the control procedure according to the first modification. FIG. 12 is a flowchart in which only the changed parts of the control of the second modification are extracted. In the figure, 1... Air flow sensor, 2... Throttle valve, 3
...Surge tank, 4...Intake pipe, 5...Injector, 6...Engine body, 8...Water temperature sensor,
9...Spark plug, ]0...Ignition coil, 11...
・Distributor, 12...crank angle sensor,
13... Cylinder sensor, 14... Exhaust pipe, 18.
...Igniter, 19...Boost pressure sensor, 20.
-ECU, 22... Throttle opening sensor, 23...
・Accelerator opening sensor, 24...Gear position sensor, 3
0... Waveform shaper, 46... A/D converter, 3
4...CPU, 36-40...Program timer, 41...FRCl 42...RAM, 43-...
ROM, 45... Output interface. Figure 6 Figure 7 Figure 9 Figure 1o Figure

Claims (3)

[Claims] (1) The first step that intermittently calculates the fluctuation value of the engine speed
a second calculating means for calculating the vibration period of the vehicle body vibration; and a third calculating means for calculating the control delay time when controlling the engine torque based on the intermittently calculated engine rotation speed fluctuation. By comprising a calculation means and a torque control means for controlling the output torque of the engine with a delay of a time equal to 1/4 of the calculated vibration period minus the control delay time, the vehicle body during acceleration can be controlled. An engine control device characterized by suppressing vibration. (2) The first calculation means further comprises means for detecting a rotation range of the engine, and when the engine is at low rotation speed, the first calculation means shortens the calculation cycle of the fluctuation value of the engine rotation speed. The engine control device according to item 1. (3) Furthermore, means for detecting the rotational range of the engine is provided, and when the engine is at low rotational speed, the torque control means is activated at a time delayed by a time equal to 5/4 of the vibration period minus the phase difference. 2. The engine control device according to claim 1, wherein the engine output torque control is performed based on the calculated fluctuation value of the engine rotational speed.