JPH0627516B2 - Engine controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device, and more particularly to an engine control device aiming at reduction of vehicle body vibration.

(Prior Art) Conventionally, for example, in a vehicle that transmits power without passing through a fluid coupling or the like, if a relatively sudden accelerator operation is performed,
The vehicle shook and shuddered, causing the front-back vibration of the vehicle body. This is because the torque change of the engine became the seismic source, which increased due to the resonance of the drive system. On the other hand, although measures for limiting the torque change of the engine and optimizing the rigidity of the drive system have been taken, they are not sufficient.

In addition, recently, there has been proposed a method of positively changing the torque of the engine to quickly converge the vibration (Japanese Patent Laid-Open No. 58-487).
No. 38). This Japanese Patent Laid-Open No. 58-48738 discloses that a change in engine speed is detected and the engine torque is made to have an inverse characteristic with respect to this 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, and rotation fluctuation is detected thereby. When the value exceeds the threshold value, the ignition advance angle is controlled according to the rotation fluctuation.

In addition, taking this JP-A-58-48738 one step further,
In the same way, there is also a proposed technology that is actively trying to change the engine torque. That is, the ideal engine torque control for quickly damping the vehicle body vibration may be achieved by decreasing the engine torque when the vehicle body longitudinal acceleration is positive and increasing the engine torque when the vehicle body longitudinal acceleration is negative. Therefore, when damping the vehicle body vibration using the engine speed change,
Theoretically, it suffices to change the engine torque by delaying the phase of the engine speed change value by 1/4 cycle with respect to the drive system resonance cycle.

(Problems to be Solved by the Invention) However, the inventors of the present application have found that the above-mentioned technique relies on an ideal engine model, and therefore the actual torque control start point is actually different due to various control delay times. , Found that there is no theoretical delay of 1/4 cycle.

The control delay time is due to the following points, for example.
The control circuit actually used for engine control (mainly,
Digital microcomputer is used), but only externally discrete data can be obtained. For example, the engine speed and the like are calculated from the cycle of the pulse signal from the sensor provided in the crankshaft, but the calculation result itself includes a time delay element, and the time ( Real-time) engine speed is not. Normally, the rotation speed sensor output is accompanied by noise, and in order to cancel the error component, the engine speed obtained above is averaged over several rotations, and this average value is held at that time. Engine speed. However, it is obvious that this average value is actually delayed in time due to the time-division control of the digital computer.

Therefore, even if the engine torque is changed by delaying the engine speed by ¼ cycle to rely on the engine speed variation as in the above-described conventional technique, the engine speed itself depends on the engine speed. The data is temporally past data, which results in torque control based on incorrect data in terms of control, resulting in a situation in which the above-described engine vibration is not reduced at all.

More specifically, the control delay time varies depending on the engine speed in view of the fact that the control microcomputer performs the engine control in synchronization with the engine speed. Therefore, if the engine rotation speed is uniformly delayed by 1/4 cycle without considering the engine rotation speed as in the above-described conventional technique, in the region where the engine rotation speed is present, this 1 The control delay time becomes longer than the delay time of / 4 cycles, resulting in insufficient vibration suppression or conversely promoting vibration.

Therefore, an object of the present invention is to provide a control device for an engine that suppresses vehicle body vibrations based on engine speed fluctuations, by adding a control delay time such as the above-described calculation delay time. The present invention enables reliable suppression of engine vibration, which was impossible in the past.

Further, the present invention proposes an engine control device capable of accurately and reliably suppressing vibration even at low rotation speed when the control delay time becomes long.

(Means for Solving Problems) The configuration of the present invention for solving the above-mentioned problems is, as shown in FIG. 1, a variation value of the engine speed in order to suppress vehicle body vibration during acceleration. The first to calculate intermittently
A second calculating means for calculating the fluctuation cycle of the engine speed fluctuation; and a second calculating means for calculating a control delay time for controlling the engine torque based on the intermittently calculated engine speed fluctuation. 3, the acceleration determining means for determining the acceleration state, and the acceleration output determining, the output torque control of the engine is delayed by a time obtained by subtracting the control delay time from a time of 1/4 of the calculated fluctuation cycle. And a torque control means for performing.

Further, an engine control device according to another aspect of the present invention is
A first calculating means for intermittently calculating a fluctuation value of the engine speed and a second calculating means for calculating a fluctuation cycle of the engine speed fluctuation.
And a third calculating means for calculating a control delay time when controlling the engine torque based on the engine speed fluctuation calculated intermittently, an acceleration determining means for determining an acceleration state, and an acceleration. At the time of judgment, the torque that controls the output torque of the engine by delaying the theoretical torque control timing for suppressing the longitudinal vibration of the vehicle body during acceleration based on the calculated fluctuation cycle by the time obtained by subtracting the above delay time. And a control means.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.
In this embodiment, the value of the difference between the engine speed fluctuation and its average value is used as a control amount for torque control, and this control amount is shifted by (vibration period / 4-control delay time) to perform torque control. It is about going. Further, there are two modified examples in this embodiment, and in both of these modified examples, torque control can be performed in this embodiment in view of the case where torque control cannot be performed in the low engine speed range. Special efforts have been made in the control in order to minimize the number of cases where it disappears.

<Engine Vibration Suppression System> The overall configuration of the engine vibration suppression system to which each of the embodiments according to the present embodiment is applied will be described with reference to FIGS. 4 to 6.

FIG. 4 is an overall view of a 4-cylinder fuel injection engine.
The parts particularly related to the present embodiment are an air flow meter 1, a throttle valve 2, an injector 5, a temperature sensor 8 for detecting a cooling water temperature, an ignition plug 9, an ignition coil 10, a distributor 11, an igniter 18, an intake pipe internal pressure B. A boost pressure sensor 19 for detecting, an engine controller (ECU) 20 for controlling the entire engine, an opening sensor 22 for detecting opening (TVO) of the throttle valve 2, and an opening sensor 23 for detecting an accelerator opening. , A position sensor 24 for detecting a gear position GP of a transmission (not shown), and the like.

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

_A crank angle signal C _A is output from the crank angle sensor 12 and a cylinder signal C _Y is output from the cylinder sensor 13 to the ECU 20 for each engine rotation, and is used for cylinder discrimination and engine rotation synchronization. To be done.

The igniter 18 is the same as a known one, and cuts the primary current when the ignition timing signal I _G rises,
The energization is restarted after a fixed time after cutting.

FIG. 5 is a diagram showing an internal configuration of the ECU 20 and connections between the ECU 20 and various sensors and the like. In the figure, the crank angle signal C _A is input to the interrupt terminal of the CPU 34 via the waveform shaping circuit 30. This signal C _A is a rotation angle signal 45 degrees before TDC, and is represented by BTDC 45 degrees, and CP
When it is input to U34, the interrupt routine is called, and, for example, the engine speed is calculated. The signal C _Y from the cylinder sensor 13 is the digital buffer 3
1, input to the CPU 34 through the input port 32,
Used for cylinder identification.

Boost pressure B is an analog signal, the intake air amount Q _a like through an analog cross Hua 33, the A / D converter 46 is converted into a digital value, the converted digital value CPU
34 is input. 36 to 40 are programmable timers (PTMs), and the data set in them are, in order from the top, ignition timing I _G , 4 for four cylinders, respectively.
One fuel injection pulse τ _{1 to} τ ₄ . A counter (FRC) that counts these PTM clock signals freely.
It is supplied from 41.

The ROM 43 stores a program of control procedures such as a flow chart described later. The RAM 42 is used to temporarily store intermediate data required for control.

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

<Principle of Torque Control> Outline of Embodiment An outline of torque control in the present embodiment is shown in FIGS.
This will be described with reference to FIG. Fig. 2 shows a macroscopic change in the engine speed N when the accelerator is stepped on and the throttle valve 2 is opened (TVO is the throttle opening). Fig. 3 shows the engine speed. It is a microscopic representation of N and the like.

The cycle of the vehicle body vibration (represented by the acceleration G) is the third cycle unless the drive system state such as the gear ratio changes.
There is almost no fluctuation as shown in FIG. That is, although there is a change in the amplitude of vibration, the vibration cycle depends on the vehicle type.
There is no change depending on the elapsed time of vibration. Further, when the vehicle body vibration occurs, the drive system is twisted, which is reflected in the fluctuation of the rotation N. In other words, these things
The vehicle body vibration is indirectly caused by the fluctuation ΔN of the engine speed N.
This means that it can be regarded as ((e) in FIG. 3). That is, since the vehicle body vibration is a periodic fluctuation, the rotational speed fluctuation ΔN has the same cycle as the vehicle body vibration, apart from the amplitude and the phase difference (FIG. 3 (e)). Therefore, ΔN is the most appropriate information for vibration suppression. Therefore, by appropriately processing this information, it is converted into the advance / retard amount ΔI _G of the ignition timing I _G for vibration suppression. Performs torque control.

The characteristics of the engine torque change control may be performed in the opposite phase of the vehicle body vibration cycle. In this case, the characteristics of the torque change control are completely opposite in phase (that is,
When the vibration acceleration G is in a phase in which the vibration acceleration G is gradually increased, the torque is controlled to be gradually decreased, and when the vibration acceleration G is gradually decreased, the output torque is decreased. The vibration can be suppressed more effectively by controlling so as to gradually increase (FIG. 3 (f)). That is, when the above-mentioned vibration acceleration is in the phase of gradually increasing, the torque is controlled to be gradually decreased, and when the vibration acceleration is gradually decreasing, the output torque is gradually increased. It is topologically convenient to use an amount that is delayed by 1/4 cycle (FIG. 3 (e)).

That is, the cycle of the torque control matches the cycle T _{360 °} (= oscillation cycle) of ΔN, and the phase difference is T _{90 °} = phase difference = oscillation cycle / 4 (... It is preferable to have a phase difference T _{90 °} such as 1). By the way, at the time of acceleration, the engine speed is basically in a rising direction, so it is necessary to detect only the change. Therefore,
In order to accurately control the torque, the DC component Δ is subtracted from the engine speed fluctuation ΔN. That is, when the vibration acceleration is in the phase of gradually increasing, the torque is controlled to be gradually decreased, and when the vibration acceleration is gradually decreasing, the output torque is gradually increased. Therefore, the characteristic of (ΔN−Δ) is The amount delayed by 4 cycles is used.

In this embodiment, since the realized by the ignition timing control torque control, in order to realize the phase control, for each each of the control cycles of the engine, the ignition timing correction ^{_{amount, ΔI ▲ G * ▼ = K}} G × (ΔN _O −Δ) is calculated, indexed and stored in memory. That is, ΔI _G thus obtained is stored in the memory as ΔI ▲ _G ^* ▼ (1), ΔI ▲ _G ^* ▼ (2) ,: ΔI ▲ _G ^* ▼ (n) over the past n times. To do. Then, the ignition timing correction amount ΔI _G (m) necessary to suppress the vibration at a certain time is ΔI _G (m) = K _G × (ΔN _O −Δ) (2) This is the index number for obtaining ΔI _G obtained in the control cycle.

The above is the basic method of torque control, but in this embodiment, in order to further improve the accuracy of control, the following concept of "control delay time" is introduced, and this "control delay time" is introduced. The torque control advanced (returned) in phase by the amount of is performed. That is, the above m is And Here, the control delay time = the actual rotational speed fluctuation and the phase difference between the calculated (detected) Δ. As will be described later, this "control delay time" is, for example, calculated by TDC (TOP DEATH CENTE
It is inevitable because it is performed every R). In other words, 1/4 equals T _{90 °} to the oscillation cycle,
If the gear is decided, it will be a fixed value, but the above "control delay time"
Includes the delay in detecting the engine speed and the delay from the ignition until the engine torque changes. That is, even if the engine speed fluctuation ΔN is detected, the detected (calculated) ΔN is delayed from the engine speed fluctuation caused by the actual body vibration G.
The calculated ΔN corresponds to the actual rotation speed fluctuation ΔN advanced by the “control delay time”. Therefore, by subtracting the "control delay time" from the "vibration cycle / 4", the phase of the torque control is "control delay time" rather than "vibration cycle / 4".
It is necessary to proceed only.

Now, let's specifically obtain this "control delay time". In order to control the torque, it is necessary to calculate the engine speed N, calculate ΔN, and calculate Δ. If the engine speed N is calculated for each TDC cycle, the "control delay time" calculated by the engine speed N is 0.5TDC. For the same reason, the “control delay time” calculated by the rotation speed fluctuation ΔN is 0.5 TDC. Further, if the averaging for the rotational speed fluctuation average value Δ is a moving average of, for example, two rotations (that is, 4TDC), the “control delay time” by this average value calculation is 1.5TDC. Generally, in the case of four cylinders, the "control delay time" when taking the n-rotation moving average is {0.5+ (n-1)} TDC. The "delay" from ignition to the actual torque generation is 0.5TDC. This "delay" depends on the explosive burning rate.

When the above delay times are summarized, the total “control delay time” until the calculation ignition torque is generated is 3.0 TDC. When forward and backward the ignition timing for the foregoing torque control, because an alien 4-cylinder engine is once engine ignition in two revolutions, "control delay time" per revolution of the engine T _CR is Is.

In this embodiment, ΔI ▲ _G ^* that was obtained and stored in the past
From the ▼, the delay time T _R T _R = T _{90 °} -T _CR (ms) (4) The past one is taken out and used. by the way,
In general engine control using a digital computer, the control amount is stored at regular time intervals, so this time interval is set to 5 as in the embodiment described later.
If ms, the index m mentioned above is Becomes

Try to use the previously stored ΔI ▲ _G ^* ▼.

FIG. 9 is a table showing the resonance frequency of vibration at each gear position (GP) and the phase difference T _{90 °} / 5 and the like.

Now, the ignition cycle becomes longer as the engine speed is lower, so that this "control delay time" becomes longer. The delay time T
_R is T _R = T _{90 °} -T _CR , and in consideration of the equation (3), T _R is negative at a certain gear position GP, that is, In the engine rotation speed region where the above, the control of this embodiment becomes impossible. Because the delay time T _R is negative, based on the future control amount (Δ-ΔN), because it means that performs current torque control. That is, in the engine speed region where T _R <0, even if torque control is performed, a torque change does not actually occur, or a phenomenon such as vehicle body vibration increases. Accordance connexion, in this case, when the fourth only control in Embodiment, T _R come summer near a negative T _{90 °,} i.e., "control delay time T
_When “ _CR ” approaches T _{180 °,} there is a hunting phenomenon such as torque control in the direction of increasing torque when the vibration is in the positive direction. Therefore, T _CR = 2T _{90 °} = T _{180 °} = vibration period / 2 (7), that is, The engine speed N _MIN1 such as is referred to as “controllable minimum engine speed (basic)”. This N _MIN1
Varies with gear position, as shown in FIG.

Further, the delay value T _R becomes “0”, that is, The engine speed N _MIN2 that _{satisfies the above condition} will be referred to as the “properly controllable minimum engine speed”. This is because the control of the above-described embodiment operates properly up to the region up to N _MIN2 . N _MIN2 also changes depending on the gear position, as shown in FIG.

Thus, only with the control of this embodiment, it is necessary to take some measures when the current engine speed N is equal to or lower than the properly controllable minimum engine speed N _MIN2 . In particular,
This is because the lowest engine speed N _MIN2 that can be properly controlled is a commonly used speed range. In other words, in the region [I] (region of N _MIN2 or more) shown in FIG. 10, the vibration suppression control can be appropriately performed.

Outline of Modifications For this purpose, two modifications for the low rotation speed operation region will be described below.

From (5), for T _CR is positive large summer even T _R, reduce the T _CR in rotation range of T _CR is increased, conversely, it may be increased T _{90 °.} The former control is the first modification, and the latter is the second modification. In the second modification, since T _{90 °} unless gear position is fixed is fixed, instead of T _{90 °,} at which the Okurashi further one period from T _{90 °,} T _{450 °} = T _{360 °} + T to use _{90 °.}

<Details of Control of Embodiment> A detailed description of control of this embodiment will be given with reference to FIGS. 8A to 8D of the basic embodiment. Here, in FIG. 8A, 5 m is obtained by PTM47.
It is the main routine of the ESA section that is activated by interruption every s. FIG. 8B shows details of the ignition timing correction amount ΔI _G calculation (step S220) in the main routine. FIG. 8C shows the crank angle signal C _A (= TD
This is a routine for calculating the engine speed and the engine speed fluctuation ΔN that are activated by an interrupt of 45 degrees before C). Further, FIG. 8D is an OCI (= OUTPUT COMPARE INTERRUPT) routine started by the PTM 36 for controlling the ignition pulse to the igniter 18.

First, the crank angle signal interruption routine of FIG. 8C will be described. When the crank rotates 45 degrees before TDC, the process proceeds to step S260 and the current time t ₁ is read from the FRC 41. In step S262, T is calculated from the interrupt time t _O calculated at the previous interrupt.
The DC cycle t _TDC (time required for crank reverse rotation) is calculated according to t _TDC = t ₁ −t _O. In step S264, the value of t ₁ is saved in t _O for the next interrupt,
At 266, the engine speed N To calculate. In step S268, the last BTDC4
From the engine speed N _O calculated at 5 degrees, the current engine speed fluctuation ΔN ^* (0) is obtained from ΔN ^* (0) = N−N _O. Here, there is a delay of 0.5 TDC. Step S
In 270, the four-time moving average ΔN is calculated from ΔN ^* (1) to ΔN ^* (3) which were calculated and stored in the past 3TDC time. Follow to ask. In this calculation, a control delay time of 1.5TDC occurs. At step S272, the next Δ
ΔN ^* (1) to ΔN ^* (3) are updated for the calculation of ₄ .

The main routine started every 5 ms will be described with reference to FIG. 8A. This main routine calculates the normal ignition timing I _GN and the ignition timing correction amount ΔI _G for suppressing vibration during acceleration, and calculates the final ignition timing I _G I _G = I _GN + ΔI _G. This I _G is calculated and output as a pulse width to the PTM 36. Now, in step S200, the normal ignition timing I _GN is calculated under normal conditions. The normal conditions are, for example, the gasoline octane number, the amount of knotting, etc. In step S202, the throttle opening TVO, the engine water temperature T _w , the gear position GP, etc. are read. In step S204, the above N _MIN1 is read.
In step S206, the engine speed N is compared with this N _MIN1 to determine whether or not it is a region where hunting occurs. In the hunting region, the process proceeds to step S234 to stop the torque control. In step S208,
If the engine water temperature T _w is equal to or lower than the predetermined value T _wa , the process similarly proceeds to step S234 and ΔI _G is set to “0”.
This is because even if the vehicle body is vibrating and it is necessary to correct the ignition timing I _G , misfire may occur if the ignition timing is delayed by performing torque control in a state where the water temperature is low. .

Steps S210 to S214 are procedures for detecting whether acceleration is started. Here, TVO _O is the throttle opening determined last time (5 ms interruption). The start of acceleration is the change in throttle opening ΔT for 5 ms.
It is determined whether or not VO is equal to or greater than the predetermined value ΔTVO _a . If acceleration is not started, ΔTVO ≦ ΔTVO _a . Therefore, in step S226, whether or not acceleration vibration is being controlled is checked by checking the set state of the flag F _AC . This F _AC flag is set in step S216, and after the start of acceleration is detected, the throttle opening change ΔTVO
Even if is small, the acceleration is being controlled for a certain period of time (FIG. 3 (d)), and during that time, it is necessary to perform the acceleration vibration control. is there. If this flag is not set, step S2
Proceeding to step 34, ΔI _G is set to “0”.

When acceleration start is detected in step S214, step S
Proceed to step 216, set the F _AC flag, and step S
At 218, the gain counter G _c is set to the initial value G _co . This initial value G _co is the time when the flag F _AC shown in FIG. 3 (d) should be set, that is, the time when the acceleration vibration suppression control should be performed. During this time, the ignition timing correction calculation is performed in step S220.

The ignition timing correction amount calculation routine will be described with reference to FIG. 8B. The purpose of this subroutine is to calculate the ignition timing correction amount ΔI _G according to the above equation and to perform limit control of this correction amount. First, step S240
Then, the control gain is calculated by K _G = K _O × K _C. Since G _C has a gradually decreasing characteristic, the control gain K _G also has a gradually decreasing characteristic. Control gain K _G is K
_It may be a constant of _O.

In step ^{_{S242, ΔI ▲ G * ▼ =}} K G × (ΔN * (0) -Δ) in accordance connexion, calculates the ignition timing correction amount for the future. Next, in step S244, the index m advanced by the control delay time is obtained from 1/4 of the vibration period.

In step S246, the ignition timing correction amount ΔI _G of the index m is searched for in the memory to suppress the current vibration. In step S248, Δ in the memory
Update the I _G map. Step S254 ~ Step S
Reference numeral 256 is a limit control of ignition timing.

Thus, the vehicle body vibration is optimized by positively utilizing the control delay time that is inevitably generated by the calculation of the engine speed N, the speed fluctuation ΔN, the average value Δ thereof, etc. for the torque control for vibration suppression. Can be suppressed to. In particular, by setting N _{MIN1 in} which hunting occurs in the lower rotation speed range above this and stopping torque control in the lower speed range, reliable vibration prevention is possible.

In the case of a 4-cylinder engine, the control delay time is 1.5
TDC is the result of four times moving average (step S270), and therefore must be recalculated each time a 6-cylinder engine is used or the number of times of moving average is increased or decreased. However, this control delay time is an amount that can be calculated in advance.

Details of First Modified Example In the above equation, in order to reduce T _CR so that T _R does not become negative, T _CR is generated mainly by averaging calculation when obtaining the average engine speed. Therefore, the number of moving averages should be changed depending on the value of the engine speed. As a result, the control delay time can be adjusted and the phase delay of the engine torque change can be minimized.
Specifically, in FIG. 10, in the region below the N _MIN2 line, the two rotation moving average of the engine is taken for the calculation of, and the one rotation moving average is taken for the other calculations. The control of the above embodiment is changed. Since one revolution of the engine corresponds to a 2TDC cycle, four Ns are sampled in the two-revolution moving average, and like the step S270 of the above embodiment, Similarly, for one-rotation moving average, And In the two-rotation moving average, the “control delay time” is 1.5 TDC as in the control of the above-described embodiment, but in the one-rotation moving average it is 0.5 TDC, and the latter control delay time is shortened by 1 TDC. In this way, 1T in the low rotation range
By shortening _TCR by DC, it becomes effective to suppress vibration in the low rotation range, particularly in the area [II] of FIG.

Since T _CR in the low rotation range is 0.5 TDC, as in the case of the above embodiment, The engine speed N _MIN3 such that is the minimum speed that this first variant can control. [II in Figure 10
As shown in [I], since N _MIN3 is located below N _MIN1 in this modification, it is understood that the controllable range is significantly improved.

The control of the first modification will be described in detail with reference to FIGS. 11A to 11C. It will be explained from FIG. 11C. Steps S340 to S348 are omitted. In step S350, N _MIN2 corresponding to the gear position is read, and in step S352, the magnitude of the current operating region N and N _MIN2 is compared. In the region of N ≧ N _MIN2 , step S3
At 58, the two rotation moving average Δ ₄ is calculated.

In the region of N <N _MIN2 , one rotation moving average Δ ₂ is calculated.

In the main routine of FIG. 11A, N _MIN1 in steps S204 and S206 of FIG. 8A of the above embodiment is _replaced with N _MIN3 in steps S284 and S286. This is because the controllable minimum rotation speed is changed to a low value by this modification. FIG. 11B also differs from FIG. 8B only in steps S244 and S324. That is, Therefore, as described above, the moving average of 4 data is taken in the region where the engine speed is N _MIN2 or more, so C = 1.5, and the moving average of 2 data is taken in the low rotation region of N _MIN2 or less. Therefore, C = 0.5. The control from step S326 onward is the same as in the above embodiment.

Effect of the first modification Thus, in the region of N _MIN3 ≤ N ≤ N _MIN2 , the number of samples of the moving average for Δ is reduced to reduce the control delay time, so that T _R does not become large negative. The vibration can be surely suppressed. In the area below N _MIN3 ,
Since the torque change control is stopped as in the above embodiment,
Hunting does not occur.

It should be noted that, considering only the phase, the smaller the number of moving averages, the better, but in order to eliminate the manufacturing error of the crank angle sensor of the type attached to the crank cam shaft,
It is necessary to take the moving average of two engine revolutions. Therefore,
If possible, you should take the moving average of two engine revolutions.

Control of Second Modification In the second modification, the operating range of the N _MIN2 line and below in FIG. It is intended to use the T _{450 °} instead of T _{90 °} in formula. Then, since the cycle of the vehicle body vibration does not change, torque control can be performed more appropriately in the region [II] of FIG. 10 than the control of the above embodiment.

In this second modification, the control flow chart of the above embodiment is modified as shown in FIG. That is, m is calculated in step S244 of FIG. 8B, and step S40 of FIG.
It is checked whether m becomes negative at 0, and only when it becomes negative, in step S402, Is calculated, and the process returns to step S246 in FIG. 8B.

Effects of the second modified example With this, since m does not become negative, reliable torque control is possible, and riding comfort in a low rotation range is improved. However,
Since the use of the T _{450 °} instead of T _{90 °,} the suppression of the first mountain of the vibration is difficult. Instead of shifting by one cycle, it is possible to shift by half cycle and reverse the sign of ΔI _G. That is, Then, ΔI _G = −ΔI ▲ _G ^* ▼ (m).

<Other Developments> Although the above-described embodiments and the like eliminate the control delay time peculiar to the digital computer, the analog computer also has the “detection delay”, and therefore can be applied to the analog computer.

In the above three embodiments, the ignition timing is corrected as a means for changing the engine torque. However, in order to achieve the above effect, the air-fuel ratio, the load of auxiliary machinery such as an alternator, the ECR amount, The throttle opening etc. may be corrected.

As means for detecting vehicle body vibration, in addition to engine speed variation, there are vehicle body acceleration, wheel speed variation, drive shaft twist, engine displacement, and the like.

Further, as the acceleration request detection means, the throttle opening change Δ
The intake pipe negative pressure B may be used in addition to the TVO and accelerator opening α. However, in this case, when the engine speed is low, the negative pressure B changes greatly even if the accelerator opening is small, so correction by the engine speed is necessary.

(Effects of the Invention) As described 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 generated in the control device is added to the torque control, and the conventional control is performed. With this, it is possible to reliably suppress engine vibration, which was actually impossible.

In particular, the averaging time when calculating the rotational speed fluctuation is shortened in the low speed range, or even 1 in the low speed range.
By using the control data delayed by the cycle for the torque control, the vehicle body vibration can be surely suppressed in the low rotation range.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration of the present invention, FIG. 2 is a diagram showing a state of an engine speed N from the start of acceleration, and FIG. For explaining the phase relationship with the torque control for suppressing the engine, FIG. 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, FIG. 6 is a functional block diagram of engine control performed by the ECU of the embodiment, FIG. 7 is a diagram for explaining how control delay occurs in the embodiment, and FIGS. 8A to 8D are related to the present embodiment. Control flow chart, FIG. 9 is a table summarizing data used in the embodiment and two modifications thereof, and FIG. 10 is a diagram summarizing operation areas of the embodiment and two modifications thereof. 11A to 11C are the first Flow chart showing a control procedure according to the shape example, FIG. 12 is a flow chart obtained by extracting only the changes of the control of the second modification. In the figure, 1 ... Air flow sensor, 2 ... Slot valve, 3 ... Surge tank, 4 ... Intake pipe, 5 ... Injector, 6 ... Engine main body, 8 ... Water temperature sensor, 9 ... Spark plug, 10 ... Ignition coil, 11 ... Dice Triviewer, 12 ... Crank angle sensor, 13 ... Cylinder sensor, 14 ... Exhaust pipe, 18 ... Igniter, 19 ... Boost pressure sensor, 20 ... ECU, 2
2 ... Slot opening sensor, 23 ... Accelerator opening sensor, 24 ... Gear position sensor, 30 ... Waveform shaper, 46 ...
A / D converter, 34 ... CPU, 36-40 ... Program timer, 41 ... FRC, 42 ... RAM, 43 ... RO
M, 45 ... Output interface.

Claims (4)

[Claims] 1. A first calculating means for intermittently calculating a fluctuation value of an engine speed, a second calculating means for calculating a fluctuation cycle of an engine speed fluctuation, and the engine speed calculated intermittently. Third calculating means for calculating a control delay time when controlling the engine torque based on the number fluctuation, acceleration judging means for judging an acceleration state, and a time of 1/4 of the calculated fluctuation cycle during acceleration judgment. And a torque control unit that controls the output torque of the engine by delaying the control delay time from the above, thereby suppressing vehicle body vibration during acceleration. 2. A means for detecting a rotation region of an engine, wherein the first calculation means shortens a calculation cycle of a variation value of the engine speed when the engine is at a low rotation speed. The control device for the engine according to the first item. 3. A means for detecting a rotation region of the engine is further provided, and when the engine is at a low rotation speed, the torque control means delays by a time obtained by subtracting the control delay time from 5/4 of the fluctuation cycle. The engine control device according to claim 1, wherein the output torque control of the engine is performed. 4. A first calculation means for intermittently calculating a fluctuation value of the engine speed, a second calculation means for calculating a fluctuation cycle of the fluctuation of the engine speed, and the engine speed calculated intermittently. Third calculating means for calculating a control delay time when controlling the engine torque based on the number variation, acceleration determining means for determining an acceleration state, and acceleration determination, based on the calculated fluctuation cycle, Vibration of the vehicle body during acceleration is provided by providing a torque control means for controlling the output torque of the engine by delaying the theoretical torque control time for suppressing the longitudinal vibration of the vehicle body by the time obtained by subtracting the delay time. A control device for an engine, which suppresses: