JP2503433B2 - Motor position initialization device for stepping motor for engine control - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a motor position initialization device for an engine control stepping motor, and more particularly to a motor position initialization device for an engine control stepping motor suitable for an automobile engine. Regarding the chemical conversion device.

[Conventional technology]

BACKGROUND ART Conventionally, in an intake system of an automobile engine, a throttle valve is provided in an intake passage, and an idle speed control (ISC) adjusting means is provided to adjust an idle opening degree of the throttle valve.

It is conceivable to use a stepping motor as the adjusting means for this idle speed control (ISC).

Further, in such an idle speed control adjusting means using the conventional stepping motor, since the position of the rod of the stepping motor can be accurately controlled, a position sensor for detecting the rod protruding position (position of the stepping motor) is provided. Can be omitted.

[Problems to be solved by the invention]

However, in such conventional adjusting means for idle speed control, the control position of the stepping motor, that is, the virtual position of the stepping motor stored in the memory of the computer or the like does not match the actual position of the stepping motor. (Hereinafter, referred to as “step-out phenomenon”), it is necessary to initialize (calibrate) the stepping motor. Such initialization is performed by driving the stepping motor to the initial position and resetting the stored value in the memory so as to correspond to this initial position.

By the way, when the ignition key is turned on or off, it may be possible to operate the stepping motor to the valve fully closed position before the initialization, but in this case it is necessary to make sure that the valve fully closed position is reached. Therefore, more pulse signals than necessary are supplied to the stepping motor. As a result, if there is no deviation between the motor position stored in the computer and the actual motor position, the stepping motor will be driven toward the valve fully closed side after reaching the valve fully closed position, and the locked state will be maintained. May cause wear and bite of the valve seat portion of the valve.

Even when the stepping motor is used for driving the EGR valve or bypassing the boost pressure (or exhaust pressure), the same problem as described above occurs.

The present invention is intended to solve such a problem, and provides a motor position initialization device for an engine control stepping motor, which is capable of appropriately performing initialization of the motor position in the stepping motor. To aim.

[Means for solving problems]

For this reason, the motor position initialization device for the engine control stepping motor of the present invention includes a motor position storage means for virtually storing the current motor position and a learning value for storing a learning value changed by a change in the state of the engine. A storage unit, a target position setting unit that sets a target motor position in consideration of the learning value from the learning value storage unit, a motor position from the motor position storage unit, and a target from the target position setting unit. And a stepping motor that operates by receiving a control signal from the control means, and an engine control driven member that is driven by the stepping motor. Output the initialization signal to the stepping motor to drive the above The motor position initialization means for moving the member to the initialization position is provided, and the motor position initialization means receives the fact that the learning value stored in the learning value storage means reaches an abnormal value, It is characterized in that it is configured with an initialization timing determining means for instructing output.

[Action]

In the motor position initialization device for an engine control stepping motor of the present invention described above, the initialization time is determined in response to the learning value used for engine control reaching an abnormal value, and is thus determined. At that time, the motor position is initialized.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 7 show an automobile engine control system equipped with a motor position initialization device for an engine control stepping motor as a first embodiment of the present invention. FIG. 1 is a block diagram of its main part, FIG. 2 is its overall configuration diagram, FIG. 3 is its block diagram, FIG. 4 is a schematic diagram showing a part of its ignition system, and FIG. 5 is its idle. FIG. 6 is a flow chart showing the speed control and motor position initialization processing, FIG. 6 is a flow chart showing the stepping motor drive routine, and FIG. 7 is a graph for explaining the operation during the idle speed control.

Now, as shown in FIG. 2, this first embodiment is applied to a V-type 6-cylinder engine (hereinafter sometimes referred to as “V6 engine”) 2. However, in this V-type 6-cylinder engine 2, A so-called multipoint injection system (MPI system) having an electromagnetic fuel injection valve “fuel injector” 6 in each intake manifold 4 connected to a nuclear cylinder is adopted.

Then, one end of an intake passage 10 is connected to the intake manifold 4 via a surge tank 8, and an air cleaner 12 is attached to the other end of the intake passage 10.

A throttle valve 14 is provided in the intake passage 10, and a bypass passage 16 that bypasses the throttle valve 14 is provided in parallel with a portion where the throttle valve 14 is provided.

In the bypass passage 16, an idle speed control valve (ICS valve) 18 and a fast idle air valve (FIA valve) 20 are arranged in parallel with each other.

The idle speed control valve 18 includes a stepping motor (also referred to as a stepper motor) 18a, a valve body 18b that is driven to open and close by the stepping motor 18a, and a return spring 18c that biases the valve body 18b in a closing direction. ing. The stepping motor 18a has four coil parts arranged in an annular shape and has a rotor (rotating body part) in a space surrounded by these coil parts. The rotor type is a rotary type (four-phase unipolar, two-phase excitation). Type)
When the pulse signals are received by the coil section in a predetermined order, the coil section is rotated left and right by a predetermined angle. The rotor of the stepping motor 18a is the rod 18 with the valve body 18b.
It is arranged coaxially with d and is screwed into it. Further, the rod 18d is provided with a rotation stop. As a result, when the stepping motor 18a is rotationally operated, the rod 18d with the valve element 18b moves along the axial direction, and the valve opening degree changes.

The fast idle air valve 20 is a wax type valve that contracts when the engine temperature is low and causes a bypass passage.
16 is opened, and as the engine temperature rises, it extends and closes the bypass passage 16.

The fuel from the fuel pump 22 is supplied to each electromagnetic medium fuel injection valve 6, and the fuel pressure from the fuel pump 22 is adjusted by the fuel pressure regulator 24. . Here, the fuel pressure regulator 24 connects the control passage 26 to one of the two chambers partitioned by the diaphragm, and connects the control passage 26 to this one chamber.
The fuel pressure is adjusted by applying a control pressure through. A return spring for determining the reference fuel pressure is provided in the chamber of the fuel pressure regulator 24.

Further, a thermo valve 28 is provided in the control passage 26. This thermo-valve 28 has a wax type temperature sensing portion in a fuel supply passage 30, and a valve body is attached to this wax type temperature sensing portion. When the fuel temperature is low, the control passage 26 is opened to open a fuel pressure regulator. While the intake passage pressure (this pressure is the pressure on the downstream side of the position where the throttle valve 14 is disposed) is introduced into the chamber of 24, as the fuel temperature rises,
Atmospheric pressure can be introduced into the chamber of the fuel pressure regulator 24 by forcibly communicating the atmosphere side opening in the thermo valve 28 and the control passage 26.

Instead of such a wax type thermo-valve 28, an electromagnetic thermo-valve having the same function as this may be used.

By the way, various controls such as fuel supply control, ignition time control, idle speed control, overheat control, fuel pump control, cooler relay on / off control, self-diagnosis (diagnosis) display control, etc. are performed on the engine 2. Various sensors are provided to perform such control. That is, as shown in FIGS. 2 to 4, an air flow sensor 32, an intake air temperature sensor 34, a throttle position sensor 36, an idle switch 38, a water temperature sensor.
40, crank angle sensor 42, top dead center sensor (TDC sensor) 44,
O ₂ sensor 46, inhibitor switch 48, cooler switch 50,
Cranking switch 52, ignition switch (sometimes called a key switch) 54, ignition key attachment / detachment sensor 55, high temperature switch 56, power steering switch (power steering switch) 58, vehicle speed reed switch 60, diagnostic switch 62, atmospheric pressure sensor 64, A door sensor 92, a lock state sensor 94, and a seat switch 96 are provided.

The air flow sensor 32 is provided in the air cleaner 12 and is an open collector output type that outputs a frequency pulse proportional to the intake air amount by detecting a Karman vortex, and is used for detecting the intake air amount.

Since the intake temperature sensor 34 is also provided in the air cleaner 12 to detect the temperature of intake air (intake temperature), a thermistor or the like is used.

Throttle position sensor 36 is throttle valve 14
Of the potentiometer (variable register) type is used.

The idle switch 38 detects that the throttle valve 14 is at the idle opening, but also has a function as a speed adjusting screw.

The water temperature sensor 40 detects the engine cooling water temperature,
A thermistor or the like is used.

The crank angle sensor 42 and the top dead center sensor 44 are respectively provided in the distributor 68 as shown in FIG. 4, but the crank angle sensor 42 detects the crank angle from the distributor angle (resolution 1 °). The top dead center sensor 44 detects the timing of the top dead center or slightly before that for each cylinder (6 cylinders), outputs a cylinder discrimination signal, and outputs a crank angle of 120 ° from the top dead center sensor 44. Since the pulse signal (reference signal) is detected every time, the engine speed can be detected by measuring the pulse signal interval.

The O ₂ sensor 46 is provided in the exhaust passage 70 on the downstream side of the collecting portion of the exhaust manifold and detects the amount of oxygen in the exhaust. The O ₂ sensor 46 is configured as an O ₂ sensor having a heater.

The inhibitor switch 48 is a switch that is turned on / off in accordance with the shift position of the automatic transmission connected to the engine 2, and is turned on in the P and N ranges, and turned off otherwise.

The cooler switch 50 is a switch that is turned on when the cooler is operating and outputs the power supply voltage or the H signal, and is turned off otherwise and outputs the L signal. The cranking switch 52 is turned on during engine cranking, and otherwise. The ignition switch 54 is a switch that is turned off. The ignition switch 54 is a switch that is turned on when the engine key is set to the IG position and the ST position, and when turned on, a spark is emitted from the spark plug through the ignition coil 72 (see FIG. 4). Ready to go.

The ignition key attachment / detachment sensor 55 is a sensor which is turned on when the ignition key (engine key) is inserted into the vehicle body side key cylinder, and is turned off otherwise.

The high temperature switch 56 is provided downstream of the catalytic converter 74 arranged in the exhaust passage 70 and detects the exhaust temperature (exhaust temperature).

The power steering switch 58 detects a hydraulic pressure when the power steering is activated and turns on.

The vehicle speed reed switch 60 outputs a pulse having a frequency proportional to the vehicle speed to detect the vehicle speed, and the diagnostic switch 62 is a switch for diagnosis.

The atmospheric pressure sensor 64 detects the atmospheric pressure by outputting a voltage proportional to the absolute pressure, and for example, a semiconductor pressure sensor is used. The atmospheric pressure sensor 64 is a computer (hereinafter,
(Also called "ECU") 76 built-in.

A door sensor (door state sensor) 92 is attached to the driver side door to detect the open / closed state of the door, and further, a lock state sensor (door state sensor) 94.
Is for detecting the locked / unlocked state of the door lock mechanism, and the seat switch 96 is for detecting the seated state in the driver's seat.

The sensors 32 to 64 and 92 to 96 are input to the ECU 76 as shown in FIG.

The ECU 76 performs centralized control such as fuel supply control, ignition timing control, idle speed control, overheat control, fuel pump control, cooler relay on / off control, and self-diagnosis display control. Its hardware configuration is an input / output interface, It is configured to include a processor (CPU), a memory such as a RAM and a ROM [including a backup memory 76a for storing an actual position, a learning value and a battery attachment / detachment detection value used for idle speed control described later].

As for the software (including the one in the form of firmware), detailed programs are set for each control described above. Such a program is stored in the program memory. The control data is two-dimensionally or three-dimensionally mapped and stored in RAM or ROM, or temporarily stored in a required latch.

Then, the control signal is output from the ECU 76 to each unit.
That is, from the ECU 76, six electromagnetic fuel injection valves 6 and an idle speed control valve 18 stepping motor
18a, ignition timing control unit (ignition device) 78, fuel pump control unit 8
Control signals suitable for 0, the cooler relay 82, the self-diagnosis display section 84, and the starter 89 as a cranking means are output.

The electromagnetic fuel injection valve 6 and the stepping motor 18a of the idle speed control valve 18 are as described above, but the electromagnetic fuel injection valve 6 operates the plunger when the pulse control signal supplied at the required duty ratio is supplied. The stepping motor 18a is a valve that can be driven to inject fuel while controlling the valve opening time. When the required pulse control signals are supplied to the four coil portions of the stepping motor 18a, depending on the energization order to each coil portion, Alternatively, the valve opening of the valve element 18b is adjusted by turning it counterclockwise.

The ignition timing control unit 78 is mainly composed of an igniter composed of an electronic circuit including a switching transistor and the like, and receives a control signal from the computer 76 to generate a coil current to the ignition coil 72 at a required timing (ignition timing). To shut off.

The fuel pump control unit 80 is configured as a control relay having a plurality of relay switches.
It controls 22 operating states.

The cooler relay 82 closes when it receives an H signal from the ECU 76 and operates the compressor, and opens when the signal from the ECU 76 becomes an L signal to deactivate the compressor, and functions as a cooler on-off relay.

The self-diagnosis display unit 84 is configured as a checker circuit that is separately connected from the outside, and displays the failure code by the blinking pattern of the LED.

Also, there are two power lines from the battery power source 66 to the computer 76, including those for the backup memory 76a, but the main line is provided with the relay contact 103b of the relay switch 103, and this relay contact 103b is a switching transistor. It is adapted to be opened and closed by a relay coil 103a which is turned on and off by 104. The output of the OR gate 102 is supplied to the base of the switching transistor 104 via the resistor 105. The OR gate 102 has one input end connected to the power supply branch line via the ignition switch 54, and the other input end connected to the ignition switch 54 and the delay circuit 100.
The power supply branch line via is connected.

As a result, the computer 76 does not turn off immediately after the ignition switch 54 is turned off, but turns off after a required delay time. This delay time is selected to be sufficient for performing the motor position initialization process described later.

The backup memory 76a is always supplied with power from the battery power source 66 regardless of whether the ignition switch 54 is on or off.

Reference numeral 11 in FIG. 2 indicates a canister, 27 indicates a positive crankcase ventilation 98, and a reservoir.

Hereinafter, among various controls performed on the engine 2, the idle spud control (ISC), which is most closely related to the present invention, will be described.

That is, as the idle speed control method in the first embodiment, the stepping motor 18a is used as an actuator and the opening speed of the idle speed control valve 18 provided in the bypass passage 16 is adjusted to control the idle speed. The method is adopted.

The idle speed control is divided into several control modes. Which control mode is in each sensor is determined, and the stepping motor 18a is driven and controlled according to the control content of the determined control mode. It will be realized.

Such idle speed control is realized by the block diagram shown in FIG. In FIG. 1, reference numeral 106 is an actual position storing means for rewriting the present motor position information in synchronism with the operation of the motor 18a and storing it virtually as an actual position Pr, and 108 is changed according to the state change of the engine 2. Learning value storage means for storing the learned value Pst, 110 is a target motor position (target position) Ps in consideration of the learning value Pst from the learning value storage means 108.
Target position setting means for setting (= Po + ΣΔP + Pst), 112 is a control means for outputting a control signal based on the actual position Pr from the actual position storage means 106 and the target motor position Ps from the target position setting means 110, 11
4 indicates a driver. The meaning of Po, ΣΔP, Pst will be described later.

Next, the operation will be described. That is, as shown in FIG. 5, when the ignition switch 54 is turned on, that is, when the ignition switch 54 is turned on, the memory of the computer 76 is initialized in step 5-1. At this time, the contents of the backup memory 76a that stores the actual position Pr and the learned value Pst (this backup memory 76a has the functions of the actual position storage means 106 and the learned value storage means 108) are not initialized. Next, in step 5-2, the engine operating conditions such as engine load, engine speed, and water temperature are input, and in step 5-3, controls other than idle speed control (fuel control, ignition timing control, etc.) Do. Note that these controls are performed by executing another routine.

Then, in step 5-4, it is determined whether or not the key switch is on (ignition switch on). Initially, the key switch is on, so the YES route is taken and the idle speed control ISC is executed. That is, first, in step 5-5, the basic position Po corresponding to the engine operating state is set, and in step 5-6, it is determined whether or not the engine is in a stable idle operating state.

Here, when the idle switch 38 is on and all of the following conditions are met, it is determined that the idle operation state is stable.

(1) The required time has elapsed after leaving the control mode performed at startup.

(2) The required time has passed after the cooler switch was turned on / off.

(3) The required time has elapsed after leaving the dashpot control mode (control in which the throttle valve is gradually closed from the required opening when the throttle valve is closed rapidly).

(4) The required time has elapsed after switching between the N range and the D range.

(5) The required time has elapsed after the idle switch 38 was turned on.

(6) Being stopped.

(7) Others The required time has elapsed since the control mode was disengaged to cope with abnormal rotation.

If NO in step 5-6, the rotation speed feedback timer is set in step 5-7 to perform position feedback control, and step 5-8 is performed.
Then, the integrated value ΣΔP = 0 of the correction position is set, and in step 5-9, the calculation of Ps = Po + ΣΔP + Pst is performed.
Here, Pst is a learning value as described above.

On the other hand, if the engine is in a stable idle operation state, it is determined in step 5-10 whether the rotation speed feedback timer is 0 or not. This is because it is better to switch to the rotation speed feedback control mode after a required time.

If YES in step 5-10, step 5-1
At 1, the target rotation speed Ns is set, and at step 5-12, the correction position ΔP is set according to the deviation ΔN between the target rotation speed Ns and the actual rotation speed Nr. After that, in Step 5-13, set the rotation speed feedback timer, and then in Step 5
At -14, it is determined whether the engine cooling water temperature Tw is higher than Ts (for example, Ts = 70 ° C.).

If NO in step 5-10, step 5-
Steps 11-14, 5-12 and 5-13 are jumped to and the processing of step 5-14 is performed.

Then, if Tw ≦ Ts (when the water temperature is low), the calculation of Ps = Po + ΣΔP + Pst is performed in step 5-9, and Ts
If w> Ts, in step 5-15, it is determined whether the rotation speed feedback control is stable, that is, whether or not x seconds have elapsed since the dead zone Nb (see FIG. 7) has been entered, and NO
In the case of, the calculation of Ps = Po + ΣΔP + Pst is performed in step 5-9. If YES at step 5-15,
In step 5-16, the learning value Pst is updated based on ΣΔP. In this case, Pst is updated gradually, that is, with a small correction change amount. Learning value Ps in step 5-16
After t is updated, in step 5-9, the operation Ps = Po + ΣΔP + Pst is performed using the updated Pst.

Then, after the processing of step 5-9, step 5-
Return to 2. In this way, the idle speed control is executed.

After that, even if the ignition switch 54 is turned off and turned off, the output of the OR gate 102 is kept at the high level for the required time by the action of the delay circuit 100, so that the transistor 104 is on and the relay contact 103b is on. Then, the computer 76 continues to operate for the time required after the ignition switch 54 is turned off. Here, the delay time set by the delay circuit 100 is a time sufficient for the initialization of the motor position. The motor position initialization is performed by a motor position initialization means 116 which outputs an initialization signal to the stepping motor 18a to move the rod 18d to the initialization position as shown in FIG. The position initializing means 116 is provided with an initialization timing determining means for determining the timing of outputting the initialization signal to the stepping motor 18a based on the learning value Pst stored in the learning value storage means 108.

The motor position initialization process will be described below. That is, as described above, the ignition switch 54
When is turned off, the initialization mode INITIALIZE is executed. First, at step 5-4, the NO route is taken, and then at step 5-17, it is judged whether or not the initialization end flag is set. Since it is initially NO, it is then determined in step 5-18 whether the initialization flag is set. In this case as well, since it is initially NO, it is then determined in step 5-19 whether the learning value Pst indicates an abnormal value.

Here, if the learning value Pst is an abnormal value, it is broken that the learning value Pst is a positive value Pstp that is sufficiently larger than the value updated by normal learning control (for example, a value around 30 for this Pstp Is selected) and the learning value
Pst is a required negative value Pstn (for example, this Pstn is −10
This is a case where the above-mentioned appropriate negative value is selected). That is, when Pstn <Pst <Pstp, the learning value Pst is not considered to be an abnormal value, but when Pst ≧ Pstp or Pst ≦ Pstn, the learning value Pst is considered to be an abnormal value.

Generally, even when the engine is operated with the same throttle opening (constant load), the engine speed decreases as it is used, that is, due to the change over time. That is, generally, the learning value Pst does not take a negative value.
Therefore, the learning value for determining whether it is abnormal
The absolute value of the upper limit value Pstp of Pst and the lower limit value Pstn are different. That is | Pstp |> | Pstn |.

If it is determined in step 5-19 that the learned value Pst is not abnormal, it is no longer necessary to initialize the learning value Pst, so that the initialization process is not performed and the execution of the main routine ends.

If it is determined in step 5-19 that the learned value Pst is abnormal, the initialization flag is set in step 5-20, and it is determined in step 5-21 whether Pst> 0. If Pst> 0 in step 5-21, that is, Pst ≧ Pstp, Ps = 0 is set in step 5-23, and if Pst ≦ 0 in step 5-21, that is, Pst ≦ Pstn.
In this case, Pr = Pr + 12 is set in step 5-22, and then Ps = 0 is set in step 5-23.

Thus, when the learning value Pst is positive, the actual position Pr
When the learning value Pst is negative without correction, the actual position Pr is corrected as follows.

First, in the case of Pst ≧ Pstp, the learning value Pst + is sufficiently large, so the actual position Pr stored in the backup memory 76a is sufficiently large without any correction, so that the fully closed position can be reliably reached. This is because a sufficient number of pulses can be supplied. Next, in the case of Pst ≦ Pstn, the actual position Pr stored in the backup memory 76a is smaller than the actual value, and therefore the correction value (Pstn | This is because it may not be possible to return to the front closed position unless, for example, 12) is added to the actual position Pr for correction.

Then, in step 5-24, it is determined whether Pr = Ps, that is, Pr = 0. Initially Pr = 0, so step 5
Take NO route at -24 and return to step 5-2. Then, after that, in steps 5-3,5-4,5-17,5-18,5-23,5-
The process of 24 is repeated. This enables stepping motor 18
Then, the rod 18d moves to the fully closed position. And Pr
When = 0, the stepping motor 18a surely reaches the fully closed position.

In this way, the actual position value Pr in the backup memory 76a becomes 0, and the stepping motor 18a also comes to the fully closed position corresponding to the actual position 0, so that the actual motor position and the actual position Pr in the computer 76 match. To do. That is, the motor position is initialized.

After that, in step 5-25, the initialization end flag is set, and in step 5-26, Ps = 60 is set,
In Step 5-27, it is judged whether Pr = Ps, that is, Pr = 60. Since Pr = 0 at the beginning, the NO route is taken in step 5-27, and the process returns to step 5-2. Then, after that, the processing of steps 5-3, 5-4,5-17, 5-26 and 5-27 is repeated. As a result, the stepping motor 18a and thus the rod 18d move to the intermediate position (the fully open position is around Pr = 120).

Then, when Pr = 60, in this case, the stepping motor 18a is set to the intermediate valve position with the actual motor position and the actual position Pr in the computer 76 coincident.

The reason why the intermediate position is set after the motor position is initialized is as follows. That is, when performing a cold start at the next engine start,
Generally, the rod 18d is advanced to the fully open position, but at this time, the rod 18d is quickly moved to the fully open position.
When the intermediate position is set in this way, not only the valve fully opening direction but also the valve closing direction can be quickly adjusted.

In this way, the motor position is not initialized each time the ignition switch 54 is turned on or off, and the motor position is initialized only when the learning value Pst shows an abnormal value. Can be eliminated, and the number of initializations can be reduced as a whole, so that the probability of a fully closed lock state can be made extremely small.

If YES in step 5-27, the processing is ended without resetting because the engine aging information about the learning value is accumulated, but step 5-28 is provided to set the learning value Pst. May be reset to 0, or a weighted average may be applied to set the learning value Pst to a desired value (a value between 0 and Pst is selected as this value).

By the way, the driving routine of the stepping motor 18a is triggered by a timer interrupt every 1/125 second as shown in FIG. 6, but first, in step 6-1, Pr and Ps
If Pr> Ps, step 6-
In step 2, one pulse on the negative side (a pulse for advancing the stepping motor 18a to the negative side by one step) is output to the stepping motor 18a, and in step 6-3, Pr = Pr-1 is set and the process returns. This leads to the target position Ps 1
Get closer to the pulse.

If Pr ≦ Ps in step 6-1, the NO route is taken, and in step 6-4, it is determined whether Pr <Ps. If Pr <Ps, in step 6-5, the stepping motor 18a outputs one pulse on the positive side (pulse for advancing the stepping motor 18a to the positive side by one step),
In step 6-6, Pr = Pr + 1 is set and the process returns.
As a result, the target position Ps is approached by one pulse.

Such an operation is repeated for each timer interrupt, and when Pr = Ps, the NO route is taken in step 6-4 and the process returns. This enables the stepping motor 18a
Eventually, the rod 18d becomes the target position.

8 to 10 show a motor position initialization device for an engine control stepping motor according to a second embodiment of the present invention. FIG. 8 is a block diagram of its essential part, and FIG. 9 is its idle speed control and FIG. 10 is a flowchart showing a motor position initialization process and the like, and FIG. 10 is a flowchart showing the stepping motor drive routine.
In FIGS. 8 to 10, the same reference numerals as those in FIGS. 1 to 7 indicate almost the same parts.

This second embodiment is also applied to the V6 engine system (see FIG. 2) as in the above-mentioned first embodiment,
In the second embodiment, different learning is performed when the air conditioner (air conditioner) is operating (on) and when it is not operating (off). When the air conditioner is off, learning called long-time learning is performed. When the air conditioner is turned on, learning called real-time learning is executed.

In the second embodiment, as in the first embodiment, the idle speed control (ISC), which is the most relevant to the present invention among various controls performed on the engine 2, will be described below.

First, the idle speed control system in the second embodiment is similar to the first embodiment described above in that the stepping motor is used.
A bypass air control method is employed in which 18a is used as an actuator and the opening speed of an idle speed control valve 18 provided in the bypass passage 16 is adjusted to control the idle speed.

The idle speed control is realized by the block diagram shown in FIG. In FIG. 8, reference numeral 106
Is an actual position storage means for rewriting the current motor position information in synchronism with the operation of the motor 18a and storing it virtually as an actual position Pr, and 108 'is a real-time learning value Prst and a real-time learning value Prst which are changed by a change in the state of the engine 2. Learning value storage means for storing the long-time learning value Plst, 110 is a learning value Pr from this learning value storage means 108 '.
Target position setting means for setting a target tartar position (target position) Ps (= Po + ΔP + Pst) in consideration of st, Plst (sometimes referred to as Pst for these Prst, Plst), 111 is a battery power source 66 When the battery is removed, the battery attachment / detachment detection value storage means 112 holds a value different from that before the removal, 112 is the actual position Pr from the actual position storage means 106 and the target position setting means 1
Control means for outputting a control signal based on the target motor position Ps from 10 and 114 are drivers. The real-time learning value Prst and the long-time learning value Plst
Will be described later.

Next, the operation will be described. That is, as shown in FIGS. 9A and 9B, the ignition switch
When 54 is turned on, that is, when the ignition switch 54 is turned on, the memory of the computer 76 is initialized in step 9-1. At this time, the contents of the backup memory 76a that stores the actual position Pr, the long time learning value Plst, and the battery attachment / detachment detection value Bon (this backup memory 76a is the actual position storage means 106, the learning value storage means 108 ', and the battery attachment / detachment detection value storage means). The contents of (having the function of 111) are not initialized. Next, in step 9-2, the engine operating conditions such as engine load, engine speed, and water temperature are input, and in step 9-3,
Control other than idle speed control (fuel control, ignition time control, etc.) is performed. Note that these controls are performed by executing another routine.

Next, at step 9-4, it is judged if the stepping motor position initialization flag (this flag is a flag that is set when the motor position of the stepping motor 18a is desired to be initialized) is set. Since it is initially NO, it is determined in step 9-5 whether or not there is a history of battery power being removed from the time when the key switch was last turned off until the time when the key switch was turned on this time. In this case, it is determined whether the battery attachment / detachment detection value Bon is out of the set value.

If there is no history of disconnection of the battery power source 66, it is determined in step 9-6 whether the key switch is on (ignition switch on). Initially, the key switch is on, so the YES route is taken and the idle speed control ISC is executed. That is, first, step 9-7
Then, it is determined whether the engine is starting. When starting the engine, in step 9-8, after setting Ps = Psta + Plst, jump to step 9-9 [see FIG. 9 (b)]. Here, Psta is a basic set opening degree for starting the engine, and Plst is a long time learning value.

Then, in step 9-9, it is determined whether Ps <Psmin. Here, Psmin is a lower limit value of the target position Ps, and a value of about 5 is selected. If Ps <Psmin
In the case of, the target position Ps is set smaller than the lower limit value, so in order to avoid this, step 9-10
Then, after setting Ps = Psmin, the process of steps 9-11 is performed. If Ps ≧ Psmin, the process directly proceeds to step 9-11. In Step 9-11, Ps> Psma
x is determined. Here, Psmax is an upper limit value of the target position Ps, and a value of, for example, about 110 to 120 is selected.
If Ps> Psmax, the target position Ps will be set larger than the upper limit value, so to avoid this,
In step 9-12, Ps = Psmax is set. In this way, the target position Ps is adjusted between the lower limit value and the upper limit value.

After the target position Ps is adjusted in this way (when the NO route is taken in step 9-11 or after the processing of step 9-12), it is determined in step 9-13 whether Pr> Ps. When the actual position Pr is smaller than the target position Ps, the stepping motor drive speed setting flag K is set to 2 in step 9-14. Here, the stepping motor drive speed setting flag K can take a value from 1 to 4, and when K = 1, the stepping motor 18a is driven at a high speed (for example, 250 pps) and K =
In the case of 2, the stepping motor 18a is set to medium speed (for example, 125pp
s), stepping motor 18a when K = 3
Is driven at a low speed (for example, 8 pps), and when K = 4, the stepping motor 18a is driven at a test speed.

Therefore, when the actual position Pr is smaller than the target position Ps, the stepping motor 18a is driven at a medium speed to bring it closer to the target position Ps.

If Pr> Ps, Pr-Ps> Δ in step 9-15.
It is determined whether or not it is P _{1, and} if it is NO, then in step 9-16, P
It is determined whether r−Ps> ΔP ₂ . And Pr-Ps> Δ
If P ₁ is satisfied or if Pr−Ps <ΔP ₂ is satisfied, the stepping motor 18a is driven at medium speed in step 9-14. Furthermore, Pr−Ps ≦ ΔP ₁ is satisfied, and Pr−Ps
If s ≧ ΔP ₂ is satisfied, K = 3 in step 9-17.
And As a result, the stepping motor 18a is driven at a low speed. Here, ΔP ₁ > ΔP ₂ .

As a result, when the actual position Pr is larger than the target position Ps, the stepping motor 18a is driven at a medium speed in the range where the difference Pr−Ps is larger than ΔP ₁ , and the difference Pr−Ps.
The stepping motor 18a is driven at a low speed when s is between ΔP ₁ and ΔP _2, and the stepping motor 18a is driven at a medium speed within a range where the difference Pr−Ps is smaller than ΔP ₂ , so that the target position Ps is reached. Get closer to. That is, as the actual position Pr approaches the target position Ps, the stepping motor 18a is first driven at medium speed and then at low speed, and finally driven at medium speed.

The reason why the speed is changed in this way is to prevent the engine speed from dropping sharply.

After that, the process returns to step 9-2 [see FIG. 9 (a)] to perform the subsequent processing. Then, after the engine is started, the NO route is taken in step 9-7 and step 9
At -18, it is determined whether the air conditioner is on. If the air conditioner is off, take the NO route and go to step 9-19.
It is determined whether or not the air conditioner flag (this flag is set when the air conditioner is turned on and is reset when the air conditioner is turned off). If the air conditioner has just been turned off, the air conditioner flag is in the set state, so the air conditioner flag is reset in step 9-20, the integrated value ΔP of the correction position is set to 0 in step 9-21, and the learning value Pst is set to be long. After setting using the time learning value Plst (step 9-22), step 9
At -23, the long-time learning flag (this flag is set when executing long-time learning and is reset otherwise) is set.

If it is not immediately after turning off the air conditioner, step 9 has already been performed.
Since the air conditioner flag is reset at -20, the NO route is taken at step 9-19 and the process at step 9-23 is executed.

After setting the long time learning flag, step 9-24
Basic position Po = Pnac according to engine cooling water temperature Tw
(Tw) is set, and in step 9-25, the target rotation speed Ns = Nnac (Tw) is set according to the engine cooling water temperature Tw.

On the other hand, if the air conditioner is on, YES in step 9-18.
Taking the route, it is determined in step 9-26 whether the air conditioner flag is set. If the air conditioner is just turned on, the air conditioner flag is in the reset state, so the air conditioner flag is set in step 9-27, the integrated value ΔP of the correction position is set to 0 in step 9-28, and the learning value Pst is set in real time. After setting using the learning value Prst (step 9-29), the long-time learning flag is reset in step 9-30.

If it is not immediately after the air conditioner is turned on, step 9 has already been performed.
Since the air conditioner flag is set at -27, the YES route is taken at step 9-26 and the processing at step 9-30 is executed.

After resetting the long time learning flag, step 9-
At 31 the basic position Po = Pa according to the engine cooling water temperature Tw
In addition to setting c (Tw), a target speed Ns = Nac (Tw) corresponding to the engine cooling water temperature Tw is set in step 9-32.

After setting the basic position Po and the target rotational speed Ns in this way, step 9-33 [see FIG. 9 (b)]
Then, it is determined whether the engine is in a stable idle operation state.

Here, when the idle switch 38 is on and all of the following conditions are met, it is determined that the idle operation state is stable.

(1) The required time has elapsed after leaving the control mode performed at startup.

(2) The required time has passed after the cooler switch was turned on / off.

(3) The required time has elapsed after leaving the dashpot control mode (control in which the throttle valve is gradually closed from the required opening when the throttle valve is closed rapidly).

(4) The required time has elapsed after switching between the N range and the D range.

(5) The required time has elapsed after the idle switch 38 was turned on.

(6) Being stopped.

(7) Others The required time has elapsed since the control mode was disengaged to cope with abnormal rotation.

If NO at step 9-33, step 9-
At 34, it is determined whether the engine cooling water temperature Tw is higher than the set value Ts. If Tw ≦ Ts, at step 9-35,
Assuming that the integrated value ΔP = 0 of the correction position, step 9-
At 36, the calculation of Ps = Po + ΔP + Pst is performed. Where P
st is a learning value as described above.

On the other hand, if the idle operation is stable, it is determined in step 9-37 whether the test signal is input. Here, the test signal is input when the vehicle is stopped, the shift lever is in the N range, and the ignition timing speed adjusting screw adjustment signal is in the predetermined value range. If there is no test signal input now, the NO route is taken in step 9-37, and it is judged in step 9-38 whether the rotation speed feedback timer (this timer is a timer of about 1 second) is 0 or not. It This is because it is better to switch to the rotation speed feedback control mode after a required time.

If YES in step 9-38, step 9-3
At 9, the deviation ΔN between the target rotation speed Ns and the actual rotation speed Nr is calculated, and at step 9-40, the correction position ΔPn is set according to this ΔN. After that, in step 9-41, the correction position ΔP = ΔP + ΔPn is set, and then step 9-
At 42, set the rotation speed feed pack timer, then
In step 9-43, the engine cooling water temperature Tw is set to Ts (for example, Ts
= 70 ° C).

If NO in step 9-38, step 9-38
-39, 9-40, 9-41, 9-42 jump, step 9-
Perform step 43.

When Tw ≦ Ts (when the water temperature is low), the first learning timer and the second learning timer (these timers are timers of about 1 second) in steps 9-44 and 9-45, respectively.
After setting, in step 9-36, Ps = Po + ΔP +
If Pst is calculated and Tw> Ts, step 9-4.
In step 6, it is determined whether Ps = Psmin. If NO, step 9
-Set the first learning timer at -47, then step 9-
At 48, it is determined whether the rotation speed feedback control is stable or whether the step ΔN is within the dead zone Nb (see FIG. 7). If NO, at step 9-45, the second
After setting the learning timer, in Step 9-36, Ps =
The calculation Po + ΔP + Pst is performed.

If Ps = Psmin, the YES route is taken in step 9-46, and it is determined in step 9-49 whether the first learning timer is 0. If the first learning timer is not 0, step 9 -Take NO route at 49, step 9-
Perform 48 processes. When | ΔN | <Nb, it is determined in step 9-50 whether the second learning timer is 0. If this second learning timer is not 0, the processing in step 9-36 is performed. Then, when the first learning timer or the second learning timer becomes 0, the processing from the next step 9-51 is performed to update the learning value. In other words, step 9-43 ~
In the processing of 9-50, it is determined whether or not the learning value is updated. In other words, the actual engine speed stays within the target speed ± dead zone for about 1 second, and the engine cooling water temperature Tw is Ts or higher, or Ps is at the lower limit value, and the rotation speed feedback continues for about 1 second. If so, the learning value is updated. Then, among the learning values, there are the learning value Prst by the real-time learning and the learning value Plst by the long-time learning, so that the respective learning values Prst, Plst are updated in the next steps 9-51 and subsequent steps. First, at step 9-51, it is judged if the long time learning flag is set. If NO, that is, if the air conditioner is on and the long time learning flag is reset in step 9-30, the real time learning value Prst is updated. First, in step 9-52, set Prst = Prst ± ΔP, in step 9-53, set ΔP = 0, and then in step 9-54.
By setting Pst = Prst, real-time learning is executed.

If the long-time learning flag is set in step 9-51, the real-time learning flag is set in the next step 9-55 (this flag is set when the real-time learning mode is specially set in the long-time learning mode). Flag) is set. Generally, since it is NO, in steps 9-56,
Plst = Plst + (ΔP / Ko) and then step 9-57
By setting Pst = Plst, long time learning is executed. Where Ko is a constant.

If the real-time learning flag is set in step 9-55, the real-time learning flag is reset in step 9-58, and then step 9-59.
Then Plst = Plst + ΔP, then Δ in step 9-60.
When P = 0, the process of step 9-57 (the process of setting Pst = Plst) is executed. As a result, real-time learning using the long-time learning value is executed only once.

Then, in steps 9-54 and 9-57, Pst = Prst or P
After st = Plst is set, in step 9-36, Ps
= Po + Pst + ΔP is calculated. The updated learning value is reflected in the target position Ps.

Further, after the processing of step 9-36, the processing of step 9-2 and subsequent steps is repeated after steps 9-9 to 9-17. As a result, the actual position Pr is controlled to become the target position Ps. As a result, the idle speed control is executed while appropriately updating the learning value.

After that, even if the ignition switch 54 is turned off and turned off, the output of the OR gate 102 is kept at the high level for the required time by the action of the delay circuit 100, so that the switching transistor 104 is turned on, that is, the relay contact 103b is turned on. Hold the state of the ignition switch
The computer 76 continues to operate for the time required after turning off 54. Here, the delay time set by the delay circuit 100 is a time sufficient to initialize the motor position. The motor position initialization is as shown in FIG.
This is performed by motor position initialization means 116 that outputs an initialization signal to the stepping motor 18a to move the rod 18d to the initialization position. The motor position initialization means 116 is stored in the learning value storage means 108 '. Further, it comprises an initialization timing determining means for determining the timing of outputting the initialization signal to the stepping motor 18a based on the long time learning value Plst.

The motor position initialization process will be described below. That is, as described above, the ignition switch 54
When is turned off, the initialization mode INITIALIZE is executed. First, at step 9-6 [see FIG. 9 (a)], the NO route is taken, and then at step 9-61, it is judged if the post-key-off flag is set. Since it is initially NO, the flag after key-off is set in step 9-62. Then, in the next step, the long-time learning value Pl
It is determined whether st indicates an abnormal value.

Here, it is determined that the long-time learning value Plst is an abnormal value because the long-time learning value Plst is a positive value Pltm that is sufficiently larger than the value updated by normal learning control.
If it is larger than ax (a value around 30 is selected for this Plstlmax), and if the long-time learning value Plst is a required negative value Plstmin (for this Plstmin, an appropriate negative value of -10 or more is selected, for example). Is smaller than). That is, when Plstmin <Plst <Plstmax, the long-time learning value Plst is not considered to be an abnormal value, but Plst ≧ Pl
If stmax or Plst ≦ Plstmin, the long-time learning value Plst is regarded as an abnormal value.

Generally, the engine has the same throttle opening (constant load)
Even when the engine is operated at 1, the engine speed decreases as it is used, that is, due to aging. That is, in general, the long-time learning value Plst does not take a negative value. Therefore, the upper limit value Plstmax and the lower limit value Plstm of the long-time learning value Plst for determining whether or not there is an abnormality
Its absolute value is different from in. That is | Plstmax | ＞ | Pl
stmin |

Then, in order to determine whether the long-time learning value Plst is abnormal, first in step 9-63, Plst <Pl
It is determined whether it is stmin. If NO in step 9-63, it is determined in step 9-64 whether Plst> Plstmax. If NO at step 9-64,
Since the long-time learning value Plst is between Plstmin and Plstmax, it is determined that there is no abnormality, and in this case, since it is no longer necessary to initialize, the execution of the main routine ends without performing initialization processing.

On the other hand, if Plst <Plstmin in step 9-63, set Pr = Pr + 12 in step 9-65, set the stepping position initialization flag in step 9-66, and then set in step 9-67. Set Ps = 0.

If Plst> Plstmax, immediately proceed to Step 9-6.
After performing the process of 6, Ps = 0 is set in step 9-67.

Note that, when the long time learning value Plst is positive, the actual position Pr is not corrected, and when the long time learning value Plst is negative, the actual position Pr is corrected as follows.

First, if Plst ≧ Plstmax, the long-time learning value P
Since lst is sufficiently large, the actual position Pr stored in the backup memory 76a is sufficiently large without any correction, so that the fully closed position can be reliably reached because a sufficient number of pulses can be supplied. Yes, then Plst ≤ Plstmi
In the case of, since the actual position Pr stored in the backup memory 76a is smaller than the actual position, the lower limit value | Plstm
A correction value larger than in |
This is because it may not be possible to return to the fully closed position unless the correction is made by adding to.

After that, in step 9-68, K = 1 is set, and the stepping motor 18a is driven at a high speed.
Return to step 9-2. Then, after that, step 9-2,
After 9-3, take the YES route in step 9-4. Then, in the next Step 9-69, it is determined whether or not the initialization end flag (this flag is a flag which is set when the initialization processing is completed) is set. The first is NO, so in steps 9-70,
It is determined whether Pr = Ps, that is, Pr = 0 (because Ps = 0 is set in step 9-67). Since it is initially NO, K = 1 is set in step 9-71, and the process returns to step 9-2. After that, the processes of steps 9-2, 9-3, 9-4, 9-69, 9-70, and 9-71 are repeated until Pr = 0. As a result, the stepping motor 18a and thus the rod 1
8d moves to the fully closed position at high speed. Then, when Pr = 0, the stepping motor 18a surely reaches the fully closed position.

In this way, the actual position value Pr in the backup memory 76a becomes 0, and the stepping motor 18a also comes to the fully closed position corresponding to the actual position 0, so that the actual motor position and the actual position Pr in the computer 76 match. To do. That is, the motor position is initialized.

Thereafter, in step 9-72, the initialization end flag is set, Ps = 10 is set in step 9-73, K = 3 is set in step 9-74, and then step 9
Return to -2. After that, through steps 9-3 and 9-4, take the YES route at step 9-69, and set Pr = P at step 9-75.
s, that is, Pr = 10 (because Ps in step 9-73)
= 10)) is determined. Since this is initially NO, steps 9-73, 9-74, 9-
The process of returning to step 9-73 through 2,9-3, 9-4, 9-69, 9-75 is repeated until Pr = 10. This causes the stepping motor 18a and thus the rod 18d to move in the opening direction at low speed by 10 steps.

Then, when Pr = 10 after 10 steps, Ps = 60 is set in Step 9-76 and Pr is set in Step 9-77.
= Ps or Pr = 60 (because Ps = 60 in step 9-76)
Because it is said)) is determined. Since Pr = 10 at first, the NO route is taken in step 9-77, K = 2 is set in step 9-78, and then the process returns to step 9-2. And after that, steps 9-3, 9-
The processing of 4,9-69, 9-75, 9-76, 9-77 is repeated. As a result, the stepping motor 18a and thus the rod 18d move at an intermediate speed toward the intermediate open position (the fully open position is around Pr = 120).

When Pr = 60, the YES route is taken in step 9-77, and the stepping motor position initialization flag is reset in step 9-78. In this case, the actual motor position and the actual position in the computer 76 are reset. The stepping motor 18a is in a position to take the intermediate valve position in a state where it matches Pr.

In addition, it is necessary to set the intermediate position after initializing the motor position in this way at the next engine start.
When performing cold start, generally, the rod 18d is advanced to the fully open position, but at this time, the rod 18d is rapidly moved to the fully open position. When the intermediate position is set in this way, not only the valve fully opening direction but also the valve closing direction can be quickly adjusted.

In this way, the motor position is not initialized each time the ignition switch 54 is turned on or off, and the motor position is initialized only when the long-time learning value Plst shows an abnormal value. It is possible to reduce the number of times of initialization as a whole by eliminating the activating operation, and thereby to extremely reduce the probability of becoming the fully closed lock state.

The movement of the stepping motor 18a and then the rod 18d from the fully closed position to the intermediate position is as follows. First, it is driven at high speed to the fully closed position, then at low speed for 10 steps, and finally at medium speed to the intermediate position.

If YES in step 9-77, the long-time learning value is not reset because the engine aging information is accumulated, but the long-time learning value Plst is reset to 0, Apply the weighted average to set the long-time learning value Plst to the required value (this value is 0
Value between the current Plst and the current Plst).

By the way, if there is a history that the battery power supply 66 has been removed before turning on the key switch this time after turning off the key switch last time, this is because the battery attachment / detachment detection value Bon greatly differs from the set value. If YES in step 9-5, the battery attachment / detachment detection value Bon is set to the set value in step 9-80, the stepping motor position initialization flag is set in step 9-81, and in step 9-82. After setting the real-time learning flag, set Pr = 150 in step 9-83, set Ps = 0 in step 9-84, and set K = in step 9-85.
After setting 1, the process returns to step 9-2.

After that, through steps 9-2 and 9-3, step 9-
The YES route is taken in step 4, the NO route is taken in step 9-69, and Pr = Ps, that is, Pr = 0 in step 9-70 (because Ps = 0 is set in step 9-84).
It is judged whether or not. At first, since Pr = 150, the NO route is taken, and the process returns to step 9-2 through step 9-71. And, further steps 9-3, 9-4, 9-69, 9-70, 9-
By repeating the processing of 71, 9-2, Pr is counted down by one. Then, when Pr = 0, the motor position is initialized.

In this way, if there is a history that the battery power supply 96 has been removed during the key switch from OFF to ON, the motor position is initialized when the data stored in the backup memory 76a is changed from the original value. This is because the reliability of the idle speed control after that is lacking, and the drawback is solved by initializing the motor position.

Also, if there is a history of the battery power 66 being removed,
Since the real-time learning flag is set in step 9-82, the learning value is then corrected only once by real-time learning [step 9 in FIG. 9 (b)].
-59, 9-60].

When there is a history of attachment / detachment of the battery power source 66 as described above, the process of setting Plst = 0 may be performed before or after any of the steps 9-80 to 9-85. This is because the long-time learning value Plst may have an abnormal value due to the disconnection of the battery power source 66, and this is promptly resolved. In addition,
Even if there is no process for setting Plst = 0, if Plst indicates an abnormal value, the initialization process is automatically executed at the subsequent key switch off in steps 9-63 to 9-65. No problem.

After the initialization as described above, the stepping motor 18a and then the rod 18d are moved to the intermediate position (Pr
= 60). The operation is as described in the above initialization processing.

If there is a test signal input, step 9-
Take the YES route at 37 [see FIG. 9 (b)], set the test opening Pstest at step 9-86, set Ps = Pstest, and set the real-time learning flag at step 9-87. In step 9-88, K = 4 is set, and the process returns to step 9-2.

Here, the test opening Pstest is appropriately set according to the type of test (for example, there are tests for periodically reciprocating between two test target positions and tests for driving to the fully closed side), and K The test speed set by setting = 4 is also appropriately set according to the type of the above test.

Then, even during this test process, step 9-
Since the real-time learning flag is set in 87, the learning value is corrected only once by real-time learning (see steps 9-59 and 9-60).

As described above, when there is a history that the battery power source 66 has been removed or after the test process, the learning value is corrected only once by the real-time learning in order to initialize the learning value to a correct value.

When the rotation speed feedback timer, the first learning timer, and the second learning timer are set, for example, 1 second is set at that time, and then a predetermined value (for example, 1) is counted down for each timer interrupt at the required time interval. It is designed to go on.

By the way, the driving routine of the stepping motor 18a is triggered by timer interrupts such as every 1/250 second, every 1/125 second, every 1/8 second as shown in FIG.
A high-speed timer interrupt routine starts with a timer interrupt every 0 seconds, a medium-speed timer interrupt routine starts with a timer interrupt every 1/125 seconds, and a low-speed timer interrupt routine starts with a timer interrupt every 1/8 seconds. A test interrupt routine is started by preset timer interrupts at various times. If there is a timer interrupt every 1/250 second, it is determined in step 10-1 whether K = 1. If K = 1, a YES route is taken to drive the stepping motor 18a at high speed, and K = 1 is not satisfied. To return. If there is a timer interrupt every 1/125 second, it is determined in step 10-2 whether K = 2,
If K = 2, the YES route is taken to drive the stepping motor 18a at a medium speed, and if K = 2 is not satisfied, the process returns.

Furthermore, if there is a timer interrupt every 1/8 second, step 1
In 0-3, it is determined whether or not K = 3. If K = 3, the YES route is taken to drive the stepping motor 18a at a low speed, and if K = 3 is not satisfied, the process returns. Then, if there is a timer interrupt for each time set for the test, it is determined in step 10-4 whether K = 4, and K =
If 4, the YES route is taken to drive the stepping motor 18a at the test speed, and if K = 4, the process returns.

If the YES route is taken in steps 10-1, 10-2, 10-3, and 10-4, then in step 10-5, Pr and Ps are compared. If Pr> Ps, step 10 At -6, one pulse on the negative side to the stepping motor 18a (stepping motor 18a
Pulse for advancing one step to the negative side) is output, and in step 10-7, Pr = Pr-1 is set and the process returns. As a result, the target position Ps is approached by one pulse.

In step 10-5, if Pr≤Ps, the NO route is taken, and in step 10-8, it is determined whether Pr <Ps. If Pr <Ps, in step 10-9, one pulse on the positive side (pulse for advancing the stepping motor 18a to the positive side by one step) is output to the stepping motor 18a,
In step 10-10, Pr = Pr + 1 is set and the process returns.
As a result, the target position Ps is approached by one pulse.

This operation is repeated for each timer interrupt, and when Pr = Ps, the NO route is taken in step 10-8 and the process returns. This enables the stepping motor 18a
Eventually, the rod 18d becomes the target position.

At this time, when the flag of K = 1 is set, the stepping motor 18a is driven every 1/250 seconds of the timer interruption. Therefore, the stepping motor 18a approaches the target position at high speed, and the flag of K = 2 is set. The timer interrupt 1/125 seconds drives the stepping motor 18a every 1 second, so the stepping motor 18a approaches the target position at medium speed, and when the flag K = 3 is set, the timer interrupt 1 / Since the stepping motor 18a is driven every 8 seconds, the stepping motor 18a approaches the target position at a low speed, and when the flag of K = 4 is set, the stepping motor 18a is driven at the time set for the test. Therefore, the stepping motor 18a approaches the test target position at the test speed.

Note that the initialization of the motor position has been described using the stepping motor 18a for idle speed control as an example, but the same applies to other stepping motors for EGR valve drive control and boost pressure (or exhaust pressure) bypass control. Can be applied.

〔The invention's effect〕

As described in detail above, according to the motor position initialization device for the engine control stepping motor of the present invention,
A motor position storage means for virtually storing the current motor position, a learning value storage means for storing a learning value changed by a change in the state of the engine, and a target considering the learning value from the learning value storage means. Target position setting means for setting a motor position to be set, control means for outputting a control signal based on the motor position from the motor position storage means and the target motor position from the target position setting means, and the control means And a driven member for engine control that is driven by the stepping motor, and outputs an initialization signal to the stepping motor to move the driven member to the initialization position. It has a motor position initialization means to move,
The motor position initialization means includes an initialization timing determination means for instructing the output of the initialization signal when the learning value stored in the learning value storage means reaches an abnormal value. Therefore, unlike the conventional case, the motor position is not initialized each time the ignition switch (key switch) is turned on or off, but the motor position is initialized only when the learning value used for engine control shows an abnormal value. Therefore, it is possible to eliminate unnecessary initialization operations, which can reduce the number of initializations as a whole, and as a result, there is an advantage that the probability of a fully closed lock state can be made extremely small.

[Brief description of drawings]

1 to 7 show an automobile engine control system having a motor position initialization device for an engine control stepping motor according to a first embodiment of the present invention.
FIG. 1 is its block diagram, FIG. 2 is its overall configuration diagram, FIG. 3 is its block diagram, FIG. 4 is a schematic diagram showing a part of its ignition system, and FIG. 5 is its idle speed control and motor. Flowchart showing position initialization processing, sixth
FIG. 7 is a flow chart showing the stepping motor drive routine, FIG. 7 is a graph for explaining the operation at the time of idle speed control, and FIGS. 8 to 10 are engine control stepping as a second embodiment of the present invention. FIG. 8 shows a motor position initialization device for a motor. FIG. 8 is a block diagram of its main part, FIG. 9 is a flowchart showing its idle speed control and motor position initialization processing, and FIG. 10 is its stepping motor drive routine. It is a flowchart showing. 2 ... V-6 engine, 4 ... intake manifold, 6
...... Electromagnetic fuel injection valve (fuel injector), 8 ...
… Surge tank, 10… intake passage, 11… canister,
12 …… Air cleaner, 14 …… Throttle valve, 16 ……
Bypass passage, 18 …… idle speed control valve (ISC valve), 18a …… stepping motor, 18b
...... Valve, 18c ...... Return spring, 18d ...... Rod, 20 ...... Fast idle air valve (FIA valve), 22 ...... Fuel pump, 24 ...... Fuel pressure regulator, 26
...... Control passage, 27 ...... Positive crankcase ventilation valve, 28 ...... Thermo valve, 30 ...... Fuel supply passage, 32 ...... Air flow sensor, 34 ...... Intake air temperature sensor,
36 …… Throttle position sensor, 38 …… Idle switch, 40 …… Water temperature sensor, 42 …… Crank angle sensor,
44 …… Top dead center sensor (TDC sensor), 46 …… O ₂ sensor, 4
8 …… Inhibitor switch, 50 …… Cooler switch, 52
…… Cranking switch, 54 …… Ignition switch, 55 …… Ignition key attachment / detachment sensor, 56 …… High temperature switch, 58 …… Power steering switch (power steering switch), 60 …… Vehicle speed reed switch, 62 …… Diagnostic switch, 64 …… Atmospheric pressure sensor, 66 …… Battery power supply,
68: Distributor, 70 ... Exhaust passage, 72 ... Ignition coil, 74 ... Catalytic converter, 76 ... Computer (ECU), 76a ... Backup memory, 78 ... Ignition timing control unit, 80 ... Fuel pump Control unit, 82 ...... Cooler relay, 84 ...... Self-diagnosis display unit, 89 ...... Starter that constitutes cranking means, 92 ...... Door sensor as door state sensor, 94 ...... Lock state sensor as door state sensor, 96 …… Seat switch, 98 …… Fuel tank, 100…
... delay circuit, 102 ... OR gate, 103 ... relay switch, 103a ... relay coil, 103b ... relay contact, 104
...... Switching transistor, 105 ...... Resistor, 106 ......
Actual position storage means (motor position storage means),
108, 108 '... Learning value storage means, 110 ... Target position setting means, 111 ... Battery attachment / detachment detection value storage means, 112 ...
... control means 114 ... driver, 116 ... motor position initialization means.

Claims (1)

(57) [Claims] 1. A motor position storage means for virtually storing a current motor position, and a learning value storage means for storing a learning value changed by a change in a state of an engine.
Target position setting means for setting a target motor position in consideration of the learned value from the learned value storage means,
A control unit that outputs a control signal based on the motor position from the motor position storage unit and a target motor position from the target position setting unit; and a stepping motor that operates by receiving a control signal from the control unit. The engine control driven member driven by the stepping motor is provided, and a motor position initialization means for outputting an initialization signal to the stepping motor to move the driven member to the initialization position is provided. The position initialization means comprises an initialization timing determination means for instructing the output of the initialization signal in response to the learning value stored in the learning value storage means reaching an abnormal value. A motor position initialization device for an engine control stepping motor.