JPH0642390A - Fuel feed control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the occurrence of step-out through open loop control and to improve control precision by limiting a skip amount in which the given magnification of a unit step is driven at a time during microstep control of a step motor to drive a fuel feed regulating means. CONSTITUTION:A step motor 15 to drive a throttle valve is controlled by an ECU 20. In this case, in the ECU 20, a final target throttle opening is decided by a deciding means 50 through various computing means 51-55 based on output signals from various sensor switches to detect the running state of an engine. Meanwhile, a given operation state and a running state are decided by means 61 and 62, respectively. An S/M drive condition for a target throttle opening is decided by a means 60 according to each decision result and S/M drive of the step motor 15 is effected by means of a means 70. In which case, when microstep control of the step motor 15 is performed, a skip amount in which the given magnification of a unit step is driven at a time is limited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which an adjusting means such as a throttle valve for adjusting an intake air amount or a fuel amount supplied to an internal combustion engine such as a gasoline engine or a diesel engine is driven by a step motor. The present invention relates to drive control of a step motor.

[0002]

2. Description of the Related Art There are various examples of driving a throttle valve arranged in an intake system of an internal combustion engine with a step motor, among which, Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 63-263239 discloses a technique of driving and controlling a step motor in a coarse adjustment step and a fine adjustment step. In this example, when the internal combustion engine approaches the throttle valve command opening and the actual opening, the operation control is switched from the coarse adjustment step to the fine adjustment step.

[0003]

Although the details of how the fine adjustment step operation is executed are not clear, the amount of skip at one time by the fine adjustment step is less than the skip amount by one coarse adjustment step, and if it is large, it is 1 The skip amount is close to the skip amount of the coarse adjustment step.

However, depending on the operating condition of the internal combustion engine, the running condition of the vehicle, the load condition of the power source, etc., it may not be desirable to operate with a large skip amount close to one coarse adjustment step even in the fine adjustment step operation.

The present invention has been made in view of the above points, and an object thereof is to limit the skip amount of the microstep control under a predetermined condition such as the operating state of the internal combustion engine, thereby providing a better drivability. In addition, a fuel supply control device for an internal combustion engine is provided.

[0006]

In order to achieve the above object, the present invention provides a fuel supply adjusting means for adjusting an intake air amount or a fuel amount supplied to an internal combustion engine, and driving the fuel supply adjusting means. To supply the same drive current to the stepping motor and the excitation phase adjacent to the stepping motor 2
In a fuel supply mechanism for an internal combustion engine, which comprises phase drive control means and microstep control means for respectively supplying drive currents of different duty to adjacent excitation phases of the step motor, a unit step of the microstep control means The fuel supply control device for the internal combustion engine is provided with the skip amount limiting means for limiting the skip amount for driving a predetermined multiple at a time.

Since the skip amount limiting means can appropriately limit the skip amount by the micro-step control, it is possible to smoothly drive and run the internal combustion engine and improve drivability.

[0008]

EXAMPLES An example of the present invention shown in FIGS. 1 to 9 will be described below.

FIG. 1 is an overall schematic view of a fuel supply control device for an on-vehicle internal combustion engine of this embodiment. An intake passage 2 for supplying fuel to the internal combustion engine 1 is provided with an air cleaner 3 at its upstream end, a throttle valve 4 is provided on the way to open and close the intake passage 2, and a fuel injection valve 5 is provided on the downstream side. The flow rate of the air introduced into the intake passage 2 through the air cleaner 3 is adjusted by the throttle valve 4 into the intake manifold 6 and the intake valve 7 opens and closes with the fuel injected from the fuel injection valve 5. Through to the combustion chamber 8.

The air-fuel mixture that has flown in burns to drive the piston 9, passes through the exhaust port opened and closed by the exhaust valve 10, and is discharged from the exhaust manifold 11 to the outside of the engine through the exhaust passage.

An accelerator pedal 12 is provided on the floor of the driver's cab of the vehicle in which the internal combustion engine 1 is mounted. The accelerator pedal 12 is urged to an idle position by a spring and responds to the stepping action of the driver. To rock.

As shown in FIG. 1, the accelerator pedal 12 and the throttle valve 4 are not mechanically connected to each other, and the depression amount of the accelerator pedal 12 is an accelerator sensor composed of a potentiometer provided on the swing shaft of the accelerator pedal 12. 13, the throttle valve 4 is opened and closed by a step motor 15, and the step motor 15 is driven by the electronic control unit E.
It operates according to the drive signal from the CU20.

The drive shaft 15a of the step motor 15 is coaxial with the valve shaft 4a of the throttle valve 4 and is directly connected by a connecting portion 16 without any gear connecting device such as a gear.

The forward / reverse rotation angle of the step motor 15 directly becomes the opening / closing angle of the throttle valve 4. The opening / closing angle of the throttle valve 4 is detected by a throttle sensor 17 such as a potentiometer, and the detection signal is output from the ECU 20.
Entered in.

In the intake passage 2, an atmospheric pressure sensor 21 is provided on the upstream side, an intake pressure sensor 22 for detecting the absolute pressure of intake air is provided on the downstream side of the throttle valve 4, and the intake pressure sensor 22 is provided further downstream. An intake air temperature sensor 23 that detects the temperature of air is provided.

Further, a water temperature sensor 24 for detecting the cooling water temperature is provided at an appropriate position near the combustion chamber 8 of the internal combustion engine 1, a crank angle sensor 25 is provided in the distributor, an engine speed sensor 26, a vehicle speed sensor 27, and drive wheels. A speed sensor 28 is provided at an appropriate position. The detection signals of the above sensors are input to the ECU 20.

Others In this control device, the ACG sensor 30 for detecting the field current of the alternator, the power steering switch for detecting the presence or absence of the operation of the power steering.
31, air conditioner switch to detect whether the air conditioner is working
32 、 Starter switch to detect the starter operation
33, a battery voltage sensor 34 for detecting the battery voltage, a range selector switch 35 for detecting the range position of the shift lever, and a shift position switch 36 for detecting the shift position are provided and output a detection signal to the ECU 20 and extend from the battery. A current sensor 37 consisting of a Hall element is installed on the main wire to detect an electric load and
The detection signal is output to.

A brake switch 40, an AC main switch 41, an AC set switch 42 and an AC resume switch 43 are also provided for automatic cruise (AC) control.

A step motor 15 for operating the throttle valve 4 based on the signals from the various sensors and switches as described above.
FIG. 2 shows a schematic configuration of a control system for performing the drive control of. Throttle opening required from various positions in the process of first determining the final target throttle opening theta _O of the throttle valve 4 is computed.

That is, the θ _AP calculating means 51 for calculating the normal throttle opening θ _AP according to the depression amount AP of the accelerator pedal 12 from the accelerator sensor 13, and the throttle opening during auto cruise according to the vehicle speed V of the vehicle speed sensor 27. θ _ACR calculation means 5 that calculates θ _ACR based on the brake switch 40, etc.
2, theta _IDL for calculating the throttle opening theta _IDL during idling according to the engine speed N _E of the engine rotational speed sensor 26
Calculation means 53, θ _TCS calculation means 54 for calculating the throttle opening θ _TCS during traction control from the vehicle speed V and the driving wheel speed V _W from the driving wheel speed sensor 28, throttle for limiting engine output to prevent engine damage EC of the above five calculation means of the θ _INH calculation means 55 for calculating the opening θ _INH
U20 has a throttle opening theta _AP that each conversion means is _{calculated, θ ACR, θ IDL, θ} TCS, θ target throttle opening theta _O determining means 50 from the _INH the final target throttle opening theta _O To decide.

On the other hand, the ECU 20 has a driving condition judging means 61 for judging a driving condition based on signals from various sensors and switches, and a driving condition judging means 62 for judging a vehicle driving condition. S / M driving condition determining means 60 based on the determination result in 62 to determine a driving condition for driving the step motor 15 to the target throttle opening theta _O.

[0022] The S / M drive control means 70 controls the driving of the step motor 15 in order to throttle valve 4 to the target throttle opening theta _O under the driving condition determined by the S / M driving condition determining means 60.

The step motor 15 is a hybrid type four-phase stepping motor and is driven by a two-phase excitation drive system. In addition to the normal two-phase drive, the step motor 15 is capable of micro-step drive that performs high resolution without mechanical deceleration, and two drive modes, two-phase mode and micro-step mode, can be selectively used by software. ing.

The two-phase mode is a normal driving method in which the same driving current is supplied to the adjacent excitation phases.
Rotate 1.8 degrees.

On the other hand, the micro-step mode is a driving method in which driving currents having different duty are supplied to the adjacent excitation phases, respectively, and one step (1.8 °) in the two-phase mode.
Is divided by the duty ratio to make a smaller rotation angle a skip amount for one step, and in this example, 1.8 ° is divided into 16 parts to make 0.11 ° a unit skip amount for one step. It is possible.

The rotation speed of the step motor 15 is proportional to the driving frequency f (pps). When the drive frequency f is large, the rotation speed is high and the response is good, but the drive torque is small. On the contrary, when the driving frequency f is small, the responsiveness deteriorates but the driving torque increases.

In this embodiment, the driving frequency f is 600 pps.
(TM _OH ) and 400 pps (TM _OH ) are used separately, but may be further divided according to the required rotation speed and the required drive torque. Note that the throttle opening and rotation angle are indicated by the number of steps because digital processing is performed by a computer, and 16 bits are stored using a 10-bit memory.
Expressed in base.

Lower 4 digits of 10 bits (lower 1 digit in hexadecimal)
Corresponds to the micro step mode, and the digits beyond that are 2
Corresponds to the phase mode. Therefore, in hexadecimal 10 _H ( _H is 16
(Indicated by the decimal system) is one step in the two-phase mode.
Of 8 degrees shows the rotation angle, 01 _H units 0F _H This was divided into 16
Corresponds to one step in the microstep mode.

The combination of excitation phases is 4 phases, 1 phase, 1 phase and 2
There are 4 types of phase, 2 phase and 3 phase, 3 phase and 4 phase, and there are 16 duty patterns for each, so there are 64 types of excitation patterns as a whole, and the number of steps less than 40 _H is 64 types. It corresponds to the excitation pattern.

On the other hand the driving of the step motor 15 in a two-phase mode and the chopper control is performed, changing the chopping duty at the time of driving the throttle valve and rest and when (hold), the latter holding the former drive duty D _MOV The duty D _HLD is a small value.

The procedure of drive control of the step motor 15 will be described below with reference to the flow charts shown in FIGS.

The flowchart is a routine for setting the driving conditions of the step motor 15 (FIG. 3 is a main routine, and FIGS. 4 and 5 are subroutines) and a routine for actually controlling the step motor 15 (FIG. 6 is a main routine, FIG. Substituting 7, 8 and 9)).

The step motor drive condition routine of FIG. 3 is
This is executed by an interruption of 10 msec, and first, the throttle opening θ _TH detected by the throttle sensor 17 is read (step 1), and the detection information of various sensors such as the depression amount AP of the accelerator sensor 13 is read (step 2).

Then, the process proceeds to step 3 and the step motor
Step out of 15 is detected. Stepping out of the step motor means when there is a difference between the current position stored in the control system of the step motor and the actual motor position when the step motor is controlled in open loop. Usually, the difference is the same excitation phase. It will be in a different position.

In this embodiment, the present throttle opening SM and throttle sensor stored in the control system of the throttle valve 4 are stored.
If a deviation from the throttle opening TH based on 17 (a value obtained by converting θ _TH into the number of steps) has a difference of a predetermined value or more, it is determined that the step is out of step.

This step-out detection routine is shown as a sub-routine in FIG. 4 and will be described later. Here, in FIG. 3, the routine proceeds to the next step 4, where the above-mentioned respective target throttle opening degrees θ _AP , θ _IDL , θ. Calculates _INH , θ _ACR , and θ _TCS .

From the five kinds of throttle opening degrees θ _AP , θ _IDL , θ _INH , θ _ACR and θ _TCS thus calculated, the final target throttle opening degree is determined by the target throttle opening degree θ _O determining means 50 in the next step 5. θ _O is determined.

The θ _ACR calculation means 52 fully closes the throttle opening except during auto cruise, and the θ _TCS calculation means 54 fully opens the throttle opening except during traction control.
The θ _INH calculation means 55 fully opens the throttle opening except when the output is limited.

At the next step 6, the target throttle opening θ
Step motor drive conditions are determined based on _O.

The present routine is completed in this way. Now, the step-out detection of the step motor in step 3 will be described with reference to the subroutine of FIG.

First, it is determined whether or not the flag F _{SMFS indicating} the abnormality of the step motor 15 itself is "1". If it is determined that the flag F _SMFS = 1, it is determined that there is no _step -out detection through this routine and the abnormality is detected. When there is no (F _SMFS = 0) next step
The process proceeds to 12 and it is determined whether or not the throttle sensor 17 has an abnormality. When it is determined that there is abnormality in the throttle sensor jumps to step 13, exits the routine clears the open side out-of-step count C _ER1 and close side step-out count value C _ER2.

If there is no abnormality in the throttle sensor, the routine proceeds to the next step 14, where the absolute value of the deviation between the throttle opening TH based on the throttle sensor 17 and the current stored throttle opening SM stored by the control system | TH-SM It is determined whether or not | exceeds 2D _H.

[0043] Unless exceed the 2D _H, the process proceeds to step 15 as the possibility of step-out small, the determination is further whether or less than the throttle opening TH to 05 _H based on the throttle sensor 17, 05 _H or more If so, it means that the routine is normal, and the routine proceeds to step 17, where the out-of-step count values C _ER1 and C _ER2 are cleared, and this routine is exited.

When the throttle opening TH is less than 05 _H , the routine proceeds to step 16, where the target throttle opening θ _O is 1.1.
It is determined whether or not the degree is exceeded, and if it is not exceeded, it is determined that the step has not been performed, and the procedure proceeds to step 5, but if it is more than 1.1 degrees, the process jumps to step 23 and Start processing.

On the other hand, if | TH-SM |> 2D _{H in} step 14, it is considered that there is a possibility of step out, and the process proceeds to step 18,
The throttle opening TH of the throttle sensor 17 is compared with the size of the stored throttle opening SM, and if TH> SM, there is a risk of step-out on the open side, and the routine proceeds to step 19, where the open side step-out count value C _ER1 is increased. Then, the closing side out-of-step count value C _ER2 is cleared, and in step 20, it is determined whether or not the opening side out-of-step count value C _ER1 becomes equal to or more than the out-of-step determination threshold CE, and when it is less than CE, this routine is executed. When it is exceeded and becomes CE or more, the routine proceeds to step 21, the step-out correction value K _DAC is calculated, and at step 22, the step-out flag F _DAC is set to "1". Here, the step-out correction value K _DAC is an integer multiple of 40 _H that is the closest to TH-SM.

[0046] In step 18 TH <open side out-of-step count value C _ER1 proceeds to step 23 may result in the close side step out when the SM is cleared, and ZoAyumiSusumu the closed side out-of-step count value C _ER2 In step 24, it is determined whether or not the closing side out-of-step count value C _ER2 is equal to or more than the step-out determination threshold value CE, and when it is less than CE, this routine is exited from step 24, and when it is equal to or more than CE, It is determined whether or not the stored throttle opening SM is less than 05 _H , and if it is more than 05 _H , the routine proceeds to step 26, where the step out correction value K _DAC is calculated in the same manner as in step 21, and step out is performed in step 22. the flag F _DAC sets a "1", and when the stored throttle opening SM is less than 05 _H is "1" in all閉脱tone flag F _THC as the throttle valve 4 is out-fully closed state Then, the process proceeds to step 22 and "1" is set in the step-out flag F _DAC .

After the step-out flag F _{DAC is set} to "1" in step 22, it is determined in step 28 whether or not the step motor abnormality determination timer T _SMSF has expired, and it is determined that the step motor abnormality determination timer T _SMSF has not expired. The step out occurrence count value C _DAC is cleared, and the step motor abnormality determination timer T _SMSF is reset (step 30).

After the step motor abnormality judgment timer T _SMSF is reset and started, if step out occurs again before the timer T _SMSF ends, steps 28 to 31.
Jump to step 1 to see if there are any abnormalities in the 1 and 3 phases of the excitation phase of the step motor 15 (1, 3 phase abnormality flag F _13FS ), and in step 32 whether there are any abnormalities in 2 and 4 phases (2 and 4 phases Abnormality flag F _24FS ) is discriminated.
_When "1" is _set in _13FS or _F24FS , this routine is exited, and when there is no abnormality, the process proceeds to step 33, the step-out occurrence count value C _DAC is increased, and the next step 34 Then, it is determined whether or not the step-out occurrence count value C _DAC has become _equal to or _larger than the step motor abnormality determination threshold value CD, and if it has not reached CD yet, the process _jumps to step 30 to reset the step motor abnormality determination timer T _SMSF , It is _checked again whether the out-of-step occurs within T _SMSF. If it occurs, the process proceeds from step 28 to step 31 and the out-of-step occurrence count value C
The _DAC was ZoAyumiSusumu, make the step-out continuously by repeating this C _DAC is equal to or greater than the threshold value CD occurs, "1" from the step 34 to the step motor abnormality flag F _SMFS proceeds to step 35.

When F _SMFS = 1 is _reached , the above step 11 is _repeated.
You will exit this routine from.

The above is the step motor step-out detection routine, which corresponds to step 3 in FIG.

Next, the step motor drive condition determination routine of step 6 in FIG. 3 will be described with reference to the flowchart of FIG.

First, the target throttle opening θ _O determined in step 5 is set to the step number TH _{O of the} step motor 15.
(Step 41) and proceed to step 42.

[0053] (Interrupt timer setting value of the step motor drive control) proceeds when the current step motor driving frequency in step 42 whether TM _O is high 600 pps (TM _OH) is discriminated, TM _OH if the following In step 43, it is determined whether or not the current drive duty D _MOV is 95% or more, and 95
If less than% is 600pps setting is again high driving frequency TM _OH in step 44, when D _MOV is 95% or more, 400 pps is lower driving frequency TM _OL as the driving frequency TM _O proceeds to step 48 Is set.

On the other hand, in step 42, the current drive frequency TM _O
Is not TM _OH , that is, TM _OL , the _routine proceeds to step 47, where it is judged if the drive duty D _MOV is 40% or more. If it is less than 40%, the routine proceeds to step 44, where the drive frequency TM _O is high. The driving frequency TM _OH of 600 pps is set, and if it is 40% or more, the routine proceeds to step 48, where the driving frequency TM _O is set again to the low driving frequency TM _OL of 400 pps.

As described above, TM _OH having a high driving frequency TM _O
When the drive duty D _MOV is 95% or more in the case of (600 pps), the step motor 15 is easily affected by the fluctuation of the power supply voltage due to the fluctuation of the electric load, so that the driving frequency T is low.
By lowering it to M _OL (400 pps), it is possible to secure a sufficient driving torque for accurately driving the step motor 15.

On the contrary, the driving frequency TM _O is low TM _OL (400p
When the drive duty D _MOV is less than 40% in the case of ps), the response can be improved while maintaining a sufficient drive torque by raising the drive frequency to a high TM _OH (600 pps).

When a high drive frequency TM _OH is set to the drive frequency TM _O in step 44, the next step
The drive duty table for TM _OH is searched with 45, D _MOVH corresponding to the battery voltage V _B is selected, and the drive duty D
Set _MOV to D _MOVH (step 46).

When a low drive frequency TM _OL is set to the drive frequency TM _O in step 48, the next step 49
Search the drive duty table for TM _OL with, select D _MOVL according to the battery voltage V _B , and drive duty D
Set D _MOVL to _MOV (step 50).

When the drive duty D _MOV is set in this way, next in step 51, the hold duty D _MOV is set.
Hold _HLD hold battery voltage V
Search according to _B. Further, in step 52, the table is searched for the duty correction coefficient Kμ _D based on the battery voltage V _B in the micro step mode.

As described above, the four step motor drive conditions of the drive frequency TM _O , drive duty D _MOV , hold duty D _HLD and duty correction coefficient Kμ _D are determined.

[0061] The next step 53, the engine speed N _E, it is determined whether or not a predetermined rotational speed N ₁ or less, a forced two-phase flag F2φ if beyond the N ₁ is set to "0" (step 54) , N ₁ or less, the routine proceeds to step 55, where “1” is set to the forced two-phase flag F2φ to instruct the forced two-phase drive.

That is, the step motor is forcibly driven in the two-phase drive mode as a measure against current consumption until the engine speed is equal to or lower than the predetermined value and the engine is completely started. Therefore, the forced two-phase flag F2φ is set to "1". Is set to instruct two-phase drive.

Next, the procedure for actually controlling the drive of the step motor 15 under the conditions set above will be described with reference to FIGS. 6 to 9.

[0064] First, in the main routine of the step motor control shown in FIG. 6, the set driving frequency TM _O at step 61 is set, and thereafter the driving frequency TM _O
This routine is operated in the interrupt cycle based on

[0065] In step 62, the absolute value of the difference between the number of steps TH _O and step number SM current stored throttle opening of the target throttle opening to the target number of steps S _CMD, then the step motor 15 at step 63 Determine the rotation direction of. That is, the rotation direction flag F _DIR indicating which of the opening and closing of the step motor 15 is rotating, the reversal flag F _OPP for instructing reversal of the rotation direction and the hold flag F.
Set _HLD etc.

In the next step 64, the state of the step-out flag F _DAC is determined. When "1" is set, the process proceeds to step 65, in which the step-out flag F _{DAC is set} to "0" and then the fully closed step-out flag is set. The state of F _THC is discriminated (step 66), and if it is "0", the routine proceeds to step 67, where the step-out correction value K _DAC calculated in steps 21 and 26 is added to the stored throttle opening SM to newly store it. The throttle opening SM is set, and the step-out correction is performed by correcting the stored throttle opening SM, and the process jumps to step 90.

If "1" is set in the full-closed step-out flag F _THC in step 66, the process proceeds to step 68, the full-closed step-out flag F _{THC is set} to "0", and the microstep flag Fμ.
Also set to "0" (step 69), step-out corrected then the stored throttle opening SM is set to the lower limit value SM _L performs the correction of the stored throttle opening SM, it jumps to step 90.

As described above, since the step-out correction of this embodiment is performed by correcting the stored throttle opening SM, it is possible to surely correct it in a short time by the open loop control of the step motor.

If F _DAC = 0 at step 64, it means that the step is not out. Therefore, the routine proceeds to step 71, where it is judged if the compulsory two-phase flag F2φ is "1".
If it is "1", the routine proceeds to step 73, and if F2φ = 0, the routine proceeds to the next step 72, where it is judged if the target step number S _CMD is 10 _H or more.

If the target step number S _CMD is 10 _H or more, the process proceeds to step 73, and if it is less than 10 _H , the process proceeds to step 81.

That is, the process proceeds to step 73 when it is in the two-phase mode this time, and when "1" is set in the forced two-phase flag F2φ or the target number of steps is 10 _H or more, the process proceeds to step 73, and vice versa. When F2φ = 0 and S _CMD <10 _H , the process proceeds to step 81 and the micro step mode is driven.

When the operation proceeds to step 73 because it is the two-phase mode, whether or not the previous micro-step mode was used is determined by the micro-step flag Fμ, and when Fμ = 0 and not the micro-step mode but the previous two-phase mode as well. proceeds to the subroutine of step 76, performs updating and duty D of the stored throttle opening SM, the change of the driving frequency TM _O.

In the previous step, the micro step mode (Fμ
= 1), the routine proceeds to step 74, where it is judged whether or not the first digit is 0 _H in hexadecimal notation of the memory throttle opening SM, and 0
If it is _H , the microstep flag Fμ is set to "0" (step 75), and the subroutine of step 76 is executed.

[0074] The subroutine of step 76 is shown in Figure 7, first, the target number of steps S _CMD is determined whether a 9 _H or more (step 101), when less than 9 _H is
Proceeds to step 102 as to the hold state without have a need to a two-phase drive, to determine whether a previous hold state from the hold flag F _HLD, last time hold state (F _HLD = 1) if maintained prior state Then, the process directly exits this subroutine, and if the previous driving state (F _HLD = 0), the process proceeds to step 103 and the hold flag F _HLD =
As 1, the current drive shifts to the hold state,
Sets a "1" to the duty up flag F _DUP order to increase the holding force by increasing the duty (step 104) greater instructs the duty, further the drive frequency TM _O T
Is set to a long period of M _DLY (about 100 pps) (Step 10
5) The next interrupt is prohibited for a certain period of time to suppress the vibration that accompanies the transition from the drive to the hold state and to promptly enter the stable hold state.

On the other hand, in step 101, the target number of steps is 9 _H
When the driving is to be performed as described above, the process proceeds to step 106, the holding flag F _HLD is set to 0, and in the next step 107, the inversion flag F _HLD
Determine "1" are standing _OPP, when inverted (F _OPP = 1), sets a "1" jumps to the duty up flag F _DUP in step 104, the drive frequency TM _O to TM
By setting _DLY , the vibration and step-out accompanying the reversal of the rotation direction of the step motor 15 are prevented by maintaining a high holding force and prohibiting the next interruption for a predetermined time.

On the other hand, in step 107, the inversion flag F _OPP = 0
If it is not reversed at step 108, the process proceeds to step 108, the state of the rotation direction flag F _DIR is discriminated, and if the rotation is to the open side (F
_DIR = 0), 10 _H (corresponding to one step in the two-phase mode) is added to the memory throttle opening SM to obtain a new memory throttle opening SM (step 109), and conversely when the rotation is to the closing side ( F _DIR = 1), from memory throttle opening SM
10 _H is subtracted and updated to a new stored throttle opening SM (step 110).

The above is the two-phase mode and the previous two-phase mode, or the previous microstep mode was the subroutine processing when the first digit of the memory throttle opening SM happens to be 0 _H. If the first digit of the memory throttle opening SM is not 0 _H ,
Returning to the flowchart of FIG. 7, the process proceeds from step 74 to step 77, the state of the rotation direction flag F _DIR is determined, and when the rotation is to the open side (F _DIR = 0), the memory throttle opening SM
The first digit of the memory throttle opening SM is rounded up to a new memory throttle opening SM (step 78). On the contrary, when the rotation is to the closing side (F _DIR = 1), the first digit of the memory throttle opening SM is rounded down. Then, the new memory throttle opening SM is updated (step 79).

In this way, the first digit of the memory throttle opening SM is raised or lowered to prepare for the two-phase drive, so that when the microstep drive is switched to the two-phase drive, it is possible to temporarily reverse the direction opposite to the target direction. There are no major problems and the transition can be made smoothly.

From step 78 or step 79, the routine proceeds to step 80, where the microstep flag Fμ is set to "0",
The actual output routine (step 90) to the step motor 15 is started based on the new stored throttle opening SM together with the subroutine of step 76.

The above is the two-phase mode processing, but in step 71 the forced two-phase mode is not set (F2φ = 0), and the step
If the target number of steps F _CMD is less than 10 _H at 72, the micro step mode is entered, the micro step flag Fμ is set to "1" at step 81, and the previous micro step mode is checked at step 82 to see if it was the previous micro step mode. If it is determined from the step flag Fμ, and if the previous microstep mode is also (previously Fμ = 1), the process proceeds to step 83 to determine from the inversion flag F _OPP whether or not to reverse the rotation direction, and if not (F _OPP = 0), the process proceeds to the micro-skip amount limiting routine (step 86) and when the reversal is performed ( _FOPP = 1), that is, when the previous micro-step mode is used and the current micro-step is reversed, the above-mentioned FIG.
The driving frequency TM _O jumps to step 105 of SM update such routine sets the TM _DLY of the next interrupt predetermined time (about
10ms) to prevent vibration and prevent step-out.

On the other hand, if the previous two-phase mode is determined in step 82, the process proceeds to step 84, and it is determined whether or not there is a hold instruction by the hold flag F _HLD.
HLD = 1), the process proceeds to step 85, the hold flag F _{HLD is set} to "0" to release the hold, and the process proceeds to step 86.

In the previous two-phase mode (Fμ = 0), step 84
When the drive instruction (F _HLD = 0) is given by,
Jump to step 104 of and the duty up flag F _DUP
"1" is set to, and in step 105, drive frequency TM
Set TM _DLY to _O. That is, when shifting from the 2-phase drive state to the micro step drive,
The duty of the current supplied to 15 is increased and the next interrupt is prohibited for a predetermined time to suppress vibration and prevent step-out.

By the way, when the routine proceeds to step 86, the micro-skip amount limiting routine shown in FIG. 8 is entered.

In the same micro-skip amount limiting routine,
First, at step 121, the operating state determination means 61 determines whether or not the vehicle is in the idle state. This is judged from the starter switch signal, range selector signal, vehicle speed, intake pressure, throttle opening, engine speed, etc. Especially when the engine speed is below the set deceleration speed and above the idle judgment speed, the idle state To judge.

In the idle state, the routine proceeds to step 122, where it is determined whether the electric load is large or not by the current sensor.
When it is determined from the detection signal of 37 and the electric load is not large, it proceeds to step 123 and determines whether or not to perform load correction. This load correction means, for example, when the automatic transmission shifts or when the air conditioner is started and the air conditioner switch is turned on, when the load is applied, the engine speed must be kept constant in order to maintain a constant idle speed. It is necessary to supply the planned air to this, and it means the increase correction of this supply air.

Therefore, when it is determined in step 123 that the load correction is to be executed, the process proceeds to step 124, the skip limit value μS _L is set to 0F _H, and the limit of the skip amount that can be stepped in one step in the microstep drive is maximized. (0F _H ) to improve responsiveness.

If it is not necessary to correct the load, the routine proceeds from step 123 to step 125, where the skip limit value μ
Even slightly dull responsiveness idle Set 02 _H to S _L achieve savings in power consumption.

When the electric load is large in step 122, the process proceeds to step 126 and the skip limit value μ
Set S _L to the minimum of 01 _H. That is, when the electric load is large, the electric power supplied to the step motor 15 may not be sufficient, so that the skip amount is limited to the minimum and the step motor 15 is driven accurately.

On the other hand, when not in the idle state, the step
From 121 to step 127, the traveling state determining means 62 determines whether or not the vehicle is in the traffic jam mode. For example, when the vehicle speed of 20 km / h or less frequently occurs, the traveling state determination means 62 determines the traffic jam mode.

In the traffic jam mode, the above-mentioned step 12
Set a minimum of 01 _H to the skip limit value μS _L in 6 to slow down the response and smooth driving during traffic jams.

If the mode is not the traffic jam mode, the routine proceeds to step 128, where it is determined whether the engine speed N _E is high or low. If the engine speed is high, the routine proceeds to step 129 where the skip limit value μS _L is set to the maximum 0 _{F H} and the responsiveness When the engine speed is low, proceed to step 130 and skip limit value μ
Set 02 _H to S _L, so that it can be a smooth operation than responsiveness.

In this way, by limiting the skip amount of the micro step drive according to the operating state and running state of the engine, the operation suitable for each state can be performed and the drivability can be improved.

After the skip limit value μS _L is set, the routine proceeds to skip 131, where the target step number S _CMD
If the skip limit value μS _L is smaller than the target step number S _CMD , the process proceeds to step 132, the skip limit value μS _L is set to the target step number S _CMD , and conversely the skip limit value μS _L is set. There target step number S _CMD when the target is greater than the number of steps S _CMD has been left previously.

After the skip amount of the micro-step drive is limited in this way, the process proceeds from step 86 to step 87 in FIG. 6 to determine the state of the rotation direction flag F _DIR ,
In the case of rotation to the open side (F _DIR = 0), the routine proceeds to step 88, where the stored throttle opening SM is updated by adding the target number of steps S _CMD to the stored throttle opening SM, and conversely to the closed side. In the case of rotation (F _DIR = 1), the process proceeds to step 89 and the stored throttle opening SM is updated by subtracting the target step number S _CMD from the stored throttle opening SM.

As described above, the memory throttle opening SM
Is updated, the process proceeds to step 90 and the output routine to the step motor is entered.

The routine is shown in FIG. 9. First, at step 141, the updated memory throttle opening SM is temporarily changed to M.
And store, then the stored value M is determined whether a 40 _H or more (step 142), if the 40 _H or more steps
In step 143, 40 _H is subtracted from the stored value M to obtain a new stored value M, and the process returns to step 142 to determine whether the stored value M after the subtraction is 40 _H or more.

By repeating the steps 142 and 143, the remainder obtained by dividing the original store value M by 40 _H can be set as the store value M, and when the remainder appears, the step 14 is executed.
The routine proceeds from step 2 to step 144, and the remaining stored value M is set to the count value C _NUM for determining the excitation phase and the like.

This count value C _NUM is 00 _{H to} 3F _H (0
The value of the step motor 15 to be excited next is obtained by performing a map search based on this count value C _NUM.
Can be determined, and in the case of the micro step mode, the duty of the adjacent excitation phase is also determined by map search.

After setting the count value C _NUM , it is determined in step 145 whether the duty-up flag F _DUP is set to "1" in step 104 (FIG. 7), and F _DUP
If = 1, in step 148 the duty up flag F
_{Return DUP} to "0" and jump to step 150. F _DUP = 0
Then, in the next step 146, the micro step flag Fμ
If it is in the micro step mode (Fμ = 1), the process proceeds to step 152 and the drive control in the micro step mode is set.
If it is the phase mode (Fμ = 0), the process proceeds to step 147, it is judged from the hold flag F _HLD whether or not there is a hold instruction, and if there is a hold instruction (F _HLD = 1), the step
In step 148, the two-phase hold state is set, and if it is a drive instruction (F _HLD = 0), step 150 is entered and the two-phase drive state is set.

That is, when there is no duty up instruction (F _DUP = 0), in the two-phase mode (F μ = 0), and when the hold instruction (F _HLD = 1), the _routine proceeds to step 148, where the step motor 15 1, 3 The hold duty value D _HLD is set to the chopping duty φ1, 3D, φ2, 4D of the two-phase and two- and four-phase excitation currents, and in the next step 149, the excitation phase is determined by map search based on the count value C _NUM .

There is no instruction to increase the duty (F
_DUP = 0), 2-phase mode (Fμ = 0), drive instruction (F
_{When HLD} = 0), the process proceeds to step 150, and the driving duty value D is set to the chopping duty φ1, 3D, φ2, 4D of the excitation current of the 1st, 3rd phase and 2nd and 4th phase of the step motor 15.
Set the _MOV, and at the next step 151, the count value C
_The excitation phase is determined by map search based on _NUM .

The drive duty value D _MOV is naturally larger than the hold duty value D _HLD , and this is because the drive torque can be secured at the time of hold even if the duty value is small.

When a duty-up instruction is issued (F _DUP = 1), the process proceeds from step 148 to step 150.
Therefore, the large drive duty value D _MOV is set to the chopping duty φ1, 3D, φ2, 4D.

That is, when reversing by two-phase driving, when shifting from driving to the hold state, and when shifting from two-phase driving to microstep driving, in order to suppress vibration and prevent out-of-step, step 104 (FIG. 7) is used. ), The duty-up flag F _DUP is set to "1" to set the chopping duty of the exciting current to the large drive duty value D _MOV .

When the microstep mode is instructed (Fμ = 1), the routine proceeds from step 146 to step 152, where the excitation phase and duty Yn (1,3 phase duty), Zn (2,4) in the microstep mode are given. The phase duty is searched for in the map based on the count value C _NUM .

Then, in the next step 153, the duty correction coefficients Kμ _D obtained from the battery voltage V _{B in} step 52 (FIG. 5) are multiplied by the duties Yn, Zn to obtain the 1-, 3-phase and 2-, 4-phase signals. Chopping duty φ1,
Set to 3D, φ2, 4D.

In this way, the excitation phase of the two-phase drive or the micro-step drive and the duty of each excitation phase are set and output to the step motor 15 as a drive control signal in step 154, and the step motor 15 is drive-controlled. It

In this embodiment, as described above, the step motor is
In the microstep mode, the skip amount of one step is normally limited to a small value in the idle state to reduce the current consumption amount.

Also, when the vehicle is running in the traffic jam mode, the skip amount is also limited to a small value to slow down the responsiveness to enable smooth driving, and the skip amount is also reduced to reduce the current consumption even when the engine speed is low. On the contrary, when the engine is running at high speed, the skip amount is not limited and the operation with good responsiveness is possible.

Further, when the electric load is large, the skip amount is limited to a small value to secure the drive torque of the throttle valve, and highly accurate open loop control can be performed.

Further, when an external load is applied to the engine in the idle state, for example, when the air conditioner is started, the skip amount is not limited and the responsiveness is improved to prevent a temporary decrease in the engine rotation and maintain a constant rotation. I am able to do so.

When the engine water temperature T _W is low in the idle state, that is, when the engine is started, the engine speed is set high in order to accelerate warm-up, so that the power generation capacity of the ACG is large and the step motor 15 that is an electric load is driven. In this case, it is not necessary to limit the skip amount, and OF _H may be set as the skip limit value μS _L.

Although the present embodiment relates to the fuel supply control of the gasoline engine, it can be applied to the fuel supply control of the diesel engine.

[0114]

As described above, according to the present invention, when the step motor for opening and closing the throttle valve is driven in the micro step mode, the amount skipped in one step is appropriately limited to prevent step-out by the open loop control with high accuracy. It is possible to open and close the throttle valve, reduce current consumption, and improve drivability.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of a fuel supply control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control system of the device.

FIG. 3 is a flowchart showing a control procedure of a step motor drive condition routine in the control system.

FIG. 4 is a flowchart showing a step-out detection routine.

FIG. 5 is a flowchart showing a step motor drive condition determination routine.

FIG. 6 is a flowchart showing a step motor control routine.

FIG. 7 is a flowchart showing an SM update, D, TM _O change routine.

FIG. 8 is a flowchart showing a micro-skip amount limiting routine.

FIG. 9 is a flowchart showing a step motor output routine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Intake passage, 3 ... Air cleaner, 4 ... Throttle valve, 5 ... Fuel injection valve, 6 ... Intake manifold, 7 ... Intake valve, 8 ... Combustion chamber, 9 ... Piston, 10 ... Exhaust valve, 11 … Exhaust manifold, 12… Accelerator pedal, 13… Accelerator sensor, 15… Step motor, 16…
Connection part, 17 ... Throttle sensor, 20 ... ECU, 21 ... Atmospheric pressure sensor, 22 ... Intake pressure sensor, 23 ... Intake temperature sensor, 24 ...
Water temperature sensor, 25 ... Crank angle sensor, 26 ... Engine speed sensor, 27 ... Vehicle speed sensor, 28 ... Driving wheel speed sensor, 30
… ACG sensor, 31… Power steering switch, 32… Air conditioner switch, 33… Starter switch, 34… Battery voltage sensor, 35… Range selector switch, 36… Shift position switch, 37… Current sensor, 40… Brake switch, 41… AC Main switch, 42 ... AC set switch, 43 ... AC resume switch, 50 ... θ _O determining means,
51 ... θ _AP computing means, 52 ... θ _ACR computing means, 53 ... θ _IDL computing means, 54… θ _TCS computing means, 55… θ _INH computing means, 60
... S / M drive condition determining means, 61 ... Operating state determining means, 62
... Running state determination means, 70 ... S / M drive control means.

Claims (4)

[Claims] 1. A fuel supply adjusting means for adjusting an intake air amount or a fuel amount supplied to an internal combustion engine, a step motor for driving the fuel supply adjusting means, and the same drive for adjacent excitation phases of the step motor. A fuel supply mechanism for an internal combustion engine, comprising: two-phase drive control means for supplying current; and microstep control means for respectively supplying drive currents of different duty to adjacent excitation phases of the step motor. 2. A fuel supply control device for an internal combustion engine, comprising: skip amount limiting means for limiting a skip amount for driving a predetermined multiple of the unit step at a time. 2. The fuel supply control device for an internal combustion engine according to claim 1, wherein the skip amount control means limits the skip amount within a predetermined amount based on an operating state of the internal combustion engine. 3. The fuel supply control device for an internal combustion engine according to claim 1, wherein the skip amount control means limits the skip amount within a predetermined amount based on a traveling state of a vehicle equipped with the internal combustion engine. . 4. The skip amount control means limits the skip amount within a predetermined amount based on a load state of a power supply that supplies a current to the step motor.
A fuel supply control device for an internal combustion engine as described above.