JPH0623560B2 - Engine controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device for controlling longitudinal vibration generated in a vehicle body during engine acceleration by controlling engine output. .

[Prior Art] In a vehicle in which engine torque is transmitted to a transmission without passing through a fluid coupling, torque fluctuations having various frequency components occur during rapid acceleration, and the frequency of this torque fluctuation is It is well known that the drive system resonates when the frequency of natural vibration is substantially equal to that of the natural vibration, which causes front-rear vibration of the vehicle body and gives a driver discomfort.

In order to suppress such a longitudinal vibration of the vehicle body, it has been proposed that the rigidity of the drive system is strengthened to suppress the vibration induced in the drive system, but this has a low vibration suppressing effect. In addition, there is a problem that the weight of the engine is increased and the fuel efficiency is impaired.

Therefore, a method has been proposed in which the torque of the engine is changed during acceleration so as to suppress the longitudinal vibration of the vehicle body without causing a problem such as an increase in the weight of the engine (for example, Japanese Patent Laid-Open No. 59-165865). (See gazette).

However, in the conventional system that suppresses the longitudinal vibration of the vehicle body during acceleration by changing the torque in this way, the timing for starting the output control of the engine during acceleration is not particularly controlled, so the torque fluctuation The natural vibration of the drive system and the natural vibration of the drive system do not always interfere well with each other, and depending on the case, there is a problem in that the convergence of the longitudinal vibration of the vehicle body is delayed.

[Object of the Invention] The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide an engine control device capable of effectively and promptly controlling longitudinal vibration generated in a vehicle body during acceleration of the engine. And

[Constitution of the Invention] In order to achieve the above-mentioned object, the present invention requires that the time until the first peak of the longitudinal vibration of the vehicle body during acceleration reaches the operating state of the engine before the start of acceleration, for example, the deceleration state or the steady state. It changes depending on whether the vehicle is in a different state or not.However, if output control is started at the first peak of the front-rear vibration, the output fluctuation and the natural vibration of the drive system strongly interfere with each other and the front-rear vibration of the vehicle body is quickly converged. Focusing attention, in an engine provided with a vehicle body vibration suppression means for suppressing the longitudinal vibration generated in the vehicle body due to the resonance of the output fluctuation and the natural vibration of the drive system during the sudden acceleration of the engine by controlling the engine output. After the acceleration is detected, after a predetermined time has elapsed, the vehicle body vibration suppressing means is output-controlled in the direction in which the engine output is reduced, and the predetermined time is before the acceleration is started. Provided is a control device for an engine, which is provided with an output control means for changing the operating state of the engine depending on whether it is in a deceleration state or a steady state.

EFFECTS OF THE INVENTION According to the present invention, the output control means changes the timing of starting the output control for suppressing the longitudinal vibration of the vehicle body depending on whether the operating state of the engine before acceleration is the deceleration state or the steady state. Since the output control start timing is controlled so as to almost coincide with the first peak of the longitudinal vibration of the vehicle body during acceleration, it is possible to strongly interfere with the output fluctuation and the natural vibration of the drive system, and Vibration can be quickly converged.

[Examples] Examples of the present invention will be specifically described below.

As shown in FIG. 1, an outer shape of an engine E is formed by a cylinder head 1 and a cylinder block 2, and a cylinder head cover 3 is attached to an upper surface of the cylinder head 1.
On the other hand, an oil pan 4 for storing lubricating oil is attached to the lower surface of the cylinder block 2. The engine E is provided with a so-called DOHC valve operating mechanism (double overhead cam) and has a first camshaft 6 mounted on the first camshaft 6.
When the intake valve 8 is opened by the cam 7 at a predetermined timing, intake air (mixture) is taken into the combustion chamber 12 from the intake passage 11 via the intake port 9, and this intake air is transferred to the piston 13
When the exhaust valve 17 is opened at a predetermined timing by the second cam 16 attached to the second cam shaft 15, the combustion gas is discharged through the exhaust port 18 A series of strokes such as discharging to the exhaust passage 19 are continuously repeated, whereby the piston 1
3 reciprocates in the axial direction in the cylinder 21, the reciprocating motion of the piston 13 is converted into the rotational motion of the crankshaft 23 by the connecting rod 22, and the rotational force of the crankshaft 23 is taken out as an engine output. Has become.

A throttle valve 25 that opens and closes in conjunction with an accelerator pedal (not shown) is provided in the intake passage 11 that supplies intake air to the combustion chamber 12. Further, in the vicinity of the intake port 9, an injector 26 is provided downstream of the injection port. It is inclined to the side.

The ignition plug 31 has an ignition coil 31.
The high voltage secondary current induced by the igniter 32
Is supplied through the spark plug 1 by this secondary current
4 produces sparks and ignites the mixture. A lead angle device (not shown) is provided in the igniter 32, and the lead angle device receives a signal from a control unit 33 (hereinafter, referred to as ECU 33) and outputs a primary current of the ignition coil 31. The cutting timing is changed to adjust the ignition advance amount.

By the way, the ECU 33 is a comprehensive control system for the engine E, which includes a vehicle body vibration suppression means and an output control means described in the claims of the present application and is composed of a microcomputer, and is detected by the throttle valve opening sensor 35. Throttle opening, intake negative pressure detected by intake negative pressure sensor 36, crank angle (engine speed) detected by crank angle sensor 37, water temperature sensor 3
8, the coolant temperature detected by 8, the O ₂ concentration in the exhaust gas detected by the O ₂ sensor 39 (air-fuel ratio), the engine displacement detected by the engine displacement sensor 40,
Transmission gear position signal detected by gear position detection switch (not shown), vehicle acceleration detection means
Predetermined control is performed by using vehicle body acceleration and the like detected by (not shown) as control information.

As functionally shown in FIG. 2, the ECU 33 is composed of an EGI circuit 41 for performing fuel injection control (air-fuel ratio control) and an ESA circuit 42 for performing ignition timing control.

Then, the EGI circuit 41 uses the intake negative pressure signal, the engine speed signal, the O ₂ sensor signal (air-fuel ratio), the throttle opening signal and the water temperature signal as input information to change the pulse width of the injector 26 to control the fuel injection. (Air-fuel ratio control) is performed.

On the other hand, the ESA circuit 42 uses the required ignition timing calculation block 4
3, a request torque calculation block 44, and an ignition timing correction block 45, and inputs an intake negative pressure signal, an engine speed signal, a throttle opening signal, a water temperature signal, a gear position signal, a vehicle body acceleration signal, and an engine displacement signal. As information, the ignition timing control for controlling the output torque of the engine E is performed by adjusting the advance angle of the advance device in the igniter 32 to change the disconnection timing of the primary current of the ignition coil 31, that is, the ignition timing. Has become.

Hereinafter, a method of controlling the engine E by the ECU 33 will be described. However, the fuel injection control is performed by an ordinary control method, and in the present embodiment, there is no involvement in suppressing the longitudinal vibration of the vehicle body during acceleration. Omitting only the ignition timing control, the control method will be described with reference to the flowcharts shown in FIGS. 3 (a) and 3 (b).

When the control is started, the normal ignition timing Tig is set in step S1.
Calculation of o is performed. The calculation of this Tigo is ESA circuit 4
The intake ignition negative pressure signal, the engine speed signal, the throttle opening signal, and the water temperature signal are used as input information by the normal ignition timing calculation subroutine in the required ignition timing calculation block 43 in FIG. So
Detailed explanation is omitted.

In step S2, it is determined whether the operating state of the engine E is the steady state or the decelerating state. This determination is performed by the steady deceleration determination subroutine using the engine displacement signal as input information. During deceleration, the engine E is displaced slightly forward due to its inertia, so this displacement is detected by the engine displacement sensor 40 to determine whether the engine E is in a steady state or in a decelerated state. When the engine E is in a deceleration state before the start of acceleration, the generation time of the first peak of the longitudinal vibration of the vehicle body during acceleration is delayed, so that the output fluctuation and the natural vibration of the drive system are interfered with each other to cause the longitudinal vibration of the vehicle body. As described later, in order to quickly converge the above, the control start timing is delayed by a predetermined value so as to be substantially coincident with the peak occurrence timing.

In step S3, the vehicle body acceleration G, the transmission gear position Pg, the throttle opening TVθ, and the water temperature Tw.
And are read.

In step S4, it is compared whether or not the water temperature Tw is lower than 40 ° C. In the present embodiment, when the engine E is in the cold state, the operating state is not stable, and the output torque of the engine E cannot be accurately controlled by the ignition timing control. Also does not suppress the longitudinal vibration of the vehicle body. As a result of the comparison, if Tw ≧ 40 ° C. (NO), the engine E is in a warm-up state, and therefore the control proceeds to step S5 in order to perform the ignition timing correction control for suppressing the longitudinal vibration of the vehicle body. . On the other hand, if Tw <40 ° C. (YES), the ignition timing correction for suppressing the longitudinal vibration of the vehicle body is not performed, the control is skipped to step S16, and the normal ignition timing Tig
Ignition is performed according to o.

In step S5, the difference ΔG between the vehicle body acceleration G read in step S3 and the vehicle body acceleration G ′ read in step S3 in the previous scan is calculated.

ΔG = G−G ′ Since each control scan is executed every predetermined constant time Δt, ΔG substantially represents the differential value of the vehicle body acceleration G with respect to time.

In step S6, the throttle opening TVθ read in step S3 and step S3 in the previous scan
Difference ΔTVθ from the throttle opening TVθ ′ read by
Is calculated. ΔTVθ substantially indicates the differential value of the throttle opening with respect to time, that is, the opening speed of the throttle valve 25, and the larger ΔTVθ indicates that the throttle valve 25 is being rapidly opened. On the other hand, at the start of acceleration, the accelerator pedal is rapidly depressed by the driver, so the throttle valve 25 is rapidly opened. Therefore, the valve opening speed ΔTVθ of the throttle valve 25 is the predetermined value α.
It can be determined whether or not the engine E has started acceleration of a predetermined magnitude or more depending on whether or not (> 0).

In step S7, it is compared whether or not ΔTVθ is less than or equal to a predetermined value α. As a result of the comparison, if ΔTVθ> α (NO), the throttle valve 25 is opening rapidly,
Since the acceleration of the engine E (above a predetermined magnitude) has just started, the control proceeds to step S8, and the acceleration counter Cacc indicating the number of scans after the start of acceleration (elapsed time after the start of acceleration) is reset (Cacc = After 0), the process proceeds to step S11 in order to correct the ignition timing for controlling the longitudinal vibration of the vehicle body.

On the other hand, as a result of the comparison in step S7, if ΔTVθ ≦ α (YES), the control proceeds to step S9, and it is compared whether or not the acceleration counter Cacc is larger than the predetermined value Dacc. As shown in FIG. 7, this Dacc is set by generalizing the number of counts corresponding to the time required for the longitudinal vibration of the vehicle body to substantially converge when the vehicle body longitudinal vibration suppression control according to the present invention is performed. It is a constant. ΔTVθ ≦ α
Since engine E is not immediately after the start of acceleration, at least some time has elapsed since the latest start of acceleration. This elapsed time is counted by the acceleration counter Cacc. When the acceleration counter Cacc is less than or equal to the predetermined value Dacc, the engine E has only passed a short time after the start of acceleration, and it is necessary to suppress the longitudinal vibration of the vehicle body. There is. As a result of the comparison, if Cacc ≦ Dacc (NO), the suppression of the front-back vibration of the vehicle body is continued, so the control proceeds to step S10, and after the acceleration counter Cacc is incremented by 1, the vehicle body front-back vibration is performed. In order to continue the ignition timing correction for suppressing the vibration, the process proceeds to step S11.

In step S11, it is compared whether or not the acceleration counter Cacc is smaller than the predetermined value C ₀ . As shown in FIG. 7, C ₀ is a control constant that is set by generalizing the count number corresponding to the time until the longitudinal vibration (acceleration) of the vehicle body after the start of acceleration reaches the first peak. Front engine E
When the vehicle is in the deceleration state, the time when the first peak of the front-back vibration of the vehicle body occurs is delayed compared to the steady state. Is set large. Then, in the present embodiment, after the start of acceleration, until the acceleration of the vehicle body reaches the first peak, if the torque is appropriately reduced, the convergence of the longitudinal vibration of the vehicle body is promoted, and the acceleration performance is hardly reduced, During the period of Cacc < ₀ , the ignition timing is corrected by open loop control. On the other hand, during the period of Cacc ≧ c ₀ , the ignition timing correction control (corresponding to the output control described in the claims of the present application) is performed by feedback control. As a result of the comparison, if Cacc <c ₀ (YES), the control is step S1.
3, the acceleration initial ignition timing correction amount ΔTig ′ is calculated by open loop control. Here, Tig 'is the transmission gear position Pg and the throttle opening T
Vθ, engine speed Ne and engine displacement (deceleration / steady state)
It is stored as a map using as a parameter. The engine speed Ne is calculated by the engine speed calculation subroutine shown in the flowchart of FIG. 5, as described later in detail. And
After the acceleration initial ignition timing correction amount ΔTig ′ is substituted for the ignition timing correction amount ΔTig, the control proceeds to step S15 to calculate the final ignition timing.

On the other hand, as a result of the comparison in step S11, if Cacc ≦ C ₀ (NO), the control proceeds to step S12, and the ignition timing correction amount ΔTig is calculated by the feedback control. Ignition timing correction amount ΔTig in step S12
Is calculated by an ignition timing correction amount calculation subroutine whose flow chart is shown in FIG. 4, as will be described later in detail. Thereafter, control proceeds to step S15 to calculate the final ignition timing.

By the way, as a result of the comparison in step S9, Cacc> Dacc
If so (YES), since the engine E has passed a predetermined time sufficient to converge the longitudinal vibration of the vehicle body after starting acceleration, the ignition timing correction for suppressing the longitudinal vibration of the vehicle body is stopped. After the ignition timing correction amount ΔTig is substituted with 0, the control proceeds to step S1 in order to calculate the final ignition timing.
Go to 5.

In step S15, the final ignition timing Tig is calculated by the following equation.

Tig = Tigo + ΔTig Subsequently, in step S16, the ignition timing to be applied to the advance device in the igniter 32 is calculated based on the final ignition timing Tig calculated in step S15. It is output to the angle device and the primary current of the ignition coil 31 is cut off at a predetermined advance amount, and a spark is generated in the spark plug 14. The calculation of the ignition timing and the output of the ignition timing signal to the advance angle device in step S16 are executed by the energization control subroutine shown in the flowchart of FIG. 6, as will be described later in detail. When the ignition timing correction control as described above is performed at the time of acceleration, the characteristic of torque with respect to time is, for example, the curve (polygonal line) G _{2 in} FIG.
become that way. As a result, the characteristic of the vehicle body acceleration G (vehicle body longitudinal vibration) with respect to time is as shown by a curve G _{4 in} FIG. 7, and the vehicle body acceleration G (vehicle longitudinal vibration) is quickly converged.

After this, the control returns to step S1 and continues.

Hereinafter, the ignition timing correction amount Δ by the ignition timing correction amount calculation subroutine executed in step S12 of the main routine
A method of calculating Tig will be described with reference to the flowchart shown in FIG.

When the ignition timing correction amount calculation subroutine is called, the ignition timing basic correction amount ΔTig ″ is calculated by the following equation in step S21.

Tig ″ = aΔG + c In the above equation, ΔG is a differential value of the vehicle body acceleration G (forward and backward vibration) calculated in step S5 of the main routine,
a and c are constants set according to the characteristics of the engine E, respectively.

In step S22, the ignition timing basic correction amount ΔTig ″
Is compared with a predetermined maximum correction amount ΔTigmax. This maximum correction amount ΔTigmax is the maximum retardation limit of the ignition timing, and if ΔTig ″ exceeds this value, problems such as misfiring occur, so ΔTig ″ is prevented from exceeding ΔTigmax. As a result of the comparison, ΔTig ″> Tigma
If x (YES), the control proceeds to step S24 by substituting ΔTigmax for ΔTig ″, while ΔTig ″ ≦ ΔTig
If it is max (NO), the control proceeds to step S24 while keeping the value of ΔTig ″.

In step S24, it is compared whether or not the ignition timing basic correction amount ΔTig ″ is less than a predetermined minimum correction amount ΔTigmin. This minimum correction amount ΔTigmin is the maximum advance angle limit of the ignition timing, and ΔTig ″ is this value. If it is smaller than this, problems such as knocking occur, so ΔTig ″ is not made smaller than ΔTigmin. As a result of comparison, ΔTi
If g "<Tigmin (YES), the control is ΔTig" and ΔT
Substituting igmin, the process proceeds to step S26, while ΔTi
If g ″ ≦ ΔTigmin (NO), the control proceeds to step S26 while leaving the value of ΔTig ″ unchanged.

In steps S26 to S27, T calculated for each scan is calculated.
An array or register ΔTd (i) (where i = 0 to n) in which only (n + 1) pieces of ig ″ are sequentially traced back from the latest
The value of is updated. In step S26, the array ΔT
The values in d (0) to ΔTd (n-1) are arrayed in ΔTd, respectively.
(1) to ΔTd (n), and in step S27 the array ΔT
The ΔTig ″ calculated in the current scan is substituted into d (0). The values stored in the array ΔTd (n) before the execution of step S26 are discarded when the execution of step S26 is performed. ΔTd (i) stores a characteristic of the ignition timing basic correction amount ΔTig ″ for a predetermined period with respect to time (hereinafter, this is referred to as a basic correction curve).

Next, in steps S28 to S30, the ignition timing correction amount ΔTig is calculated based on the basic correction curve. The ignition timing correction amount ΔTig is basically the ignition timing basic correction amount ΔTi.
It takes the same value as g ″, but if the phase of torque fluctuation and the phase of drive system vibration do not deviate by a predetermined time (preferably a time corresponding to 180 ° in crank angle), resonance of the drive system is effectively suppressed. Therefore, in each of these steps, phase matching is performed based on the basic correction curve.

In step S28, a predetermined deviation between the phase of torque fluctuation and the phase of natural vibration of the drive system, that is, the alignment delay time Tph is calculated. The phase matching delay time T
Since ph has a different value at the start and end of the ignition timing correction control for suppressing the longitudinal vibration of the vehicle body during acceleration, in the present embodiment, the phase adjustment delay time Tph ₁ at the start of the control and the value at the end are set. Based on the phase adjustment delay time Tph ₂ , the acceleration counter Cacc is calculated by linear interpolation according to the following equation according to the count number, that is, the elapsed time after the start of the control.

Tph = The Tph ₁ and Tph ₂ in (1-Cacc / Dacc) ( Tph 1 -Tph 2) + Tph 2 above equation is calculated by the following equation.

Tph ₁ = 1000 / (2 · f ₁ ) −Tc (mc) Tph ₂ = 1000 / (2 · f ₀ ) −Tc (mc) where f ₁ ; Resonance frequency at start of control (Hz) f ₀ ; Control Natural resonance number at the end (Hz) Tc; Detection delay and control delay time (ms) In step S29, the array number of the array ΔTd (i) corresponding to the phase matching delay time is calculated. Since the time required for one scan is 5 ms, the corresponding sequence number I
ph is calculated by the following formula.

Iph = Tph / 5 In step S30, the array ΔT corresponding to the array element number Iph
The ignition timing correction amount ΔTig is determined by substituting d (Iph) into ΔTig.

ΔTig = ΔTd (Iph) After this, the control returns to the main routine.

Hereinafter, the method of calculating the engine speed Ne will be described with reference to the flowchart shown in FIG. This rotation speed calculation subroutine is an interrupt routine executed every 45 ° before top dead center.

When the crank angle reaches the top dead center 45 °, the control is started, the time T _BT became TDC is read at step S41.

In step S42, the top dead center time T _{BT of} this scan
And the top dead center time T _BT ′ of the previous scan, the top dead center period H _T is calculated by the following equation.

_{H T = T BT -T BT '} (sec) in step S43, the engine rotational speed by: Ne
Is calculated.

_{Ne = 60 / H T (rpm} ) or less, the energization control by the energization control subroutine executed in step S16 of the main routine will be described referring to the flowchart shown in Figure 6.

This energization control subroutine is interrupted by the OCI (Output Compare Interrupter) method.

In step S51, it is compared whether or not the igniter 32 is energizing the primary current of the ignition coil 31. If power is not being supplied (NO), power supply to the igniter 32 is started in step S52, and control is returned to step S51.

As a result of the comparison in step S51, if the igniter 32 is energized (YES), the control proceeds to step S53, waits until the ignition timing comes, and at the moment when the ignition timing comes, the primary coil of the ignition coil 31 Cut off the power supply to. Simultaneously with the interruption of the energization, a high voltage current is generated in the secondary coil of the ignition coil 31, and this current causes a spark in the spark plug 14 to ignite the air-fuel mixture.

Thereafter, in step S54, the next energization time is set, and the control ends. When the time set in step S54 comes, this energization control subroutine starts control again (OCI method).

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an engine including a control device according to the present invention. FIG. 2 is a functionalized view of the control unit shown in FIG. 3 (a) and 3 (b) are flowcharts of the main routine showing the control method of the ignition timing control by the control unit, respectively. FIG. 4 is a flowchart showing a control method by the ignition time correction amount calculation subroutine called in the main routine shown in FIG. 3 (b). FIG. 5 is a flowchart showing a method for calculating the engine speed. FIG. 6 is a flow chart showing a control method by an energization control subroutine called in the main routine shown in FIG. 3 (b). FIG. 7 is a diagram showing characteristics of torque, acceleration, and vehicle speed with respect to time during acceleration of an engine equipped with the control device according to the present invention. E ... Engine, 1 ... Cylinder head, 2 ... Cylinder block, 11 ... Intake passage, 14 ... Spark plug,
25 ... Throttle valve, 26 ... Injector, 31 ...
... ignition coil, 32 ... igniter, 33 ...
…control unit.

Front page continuation (72) Inventor Tomomi Watanabe 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) Reference JP-A-58-48737 (JP, A) JP-A-58-152143 ( JP, A)

Claims (1)

[Claims] 1. An engine provided with a vehicle body vibration suppression means for suppressing longitudinal vibration generated in a vehicle body due to resonance of output fluctuation and natural vibration of a drive system at the time of sudden acceleration of the engine by controlling engine output. In the above, after a predetermined time has elapsed after the acceleration is detected, the output of the vehicle body vibration suppressing means is controlled so as to decrease the engine output, and the engine operating state before the acceleration of the predetermined time is the deceleration state or the steady state. An engine control device comprising output control means for changing the deceleration state in a deceleration state longer than in a steady state in accordance with