JP2000352340A - Engine control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an engine control system that provides smooth driving feel excellent drivability by securing output torque continuously when changing a driving range between idle running and non-idle running ranges. SOLUTION: A driver's requiring torque is calculated based on an engine speed and depression amount of an accelerator pedal (S1). An idling control torque necessary for maintaining the engine speed is calculated as a target idling torque (S2). A correction torque for securing the continuity of an output torque when changing a driving range from idle-running to non idle-running is calculated based on the driver's requiring torque and idling control torque (S3). Then, final target torque is calculated based on the driver's requiring torque, idling control torque and correction torque when changing a driving range (S4) and engine control based thereon is performed. In this way, continuity of output torque when changing a driving range between idle running and non- idle running ranges is secured and thus excellent drivability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device, and more particularly, to an engine control device that obtains a target torque required for an engine according to a situation and performs engine control based on the target torque.

[0002]

2. Description of the Related Art In recent years, in order to more precisely control an engine in response to a demand for improved fuel efficiency, an actuator is connected to a throttle valve instead of a mechanical type in which a conventional throttle valve and an accelerator pedal are connected by a wire. Electronically control the throttle opening of the throttle valve,
A so-called electronic control throttle type engine has been put to practical use.

According to this, the throttle valve can be opened and closed independently of the operation of the accelerator pedal. For this reason, an engine output target value to be output by the engine is set based on the accelerator pedal depression amount and the engine speed during traveling (non-idle operation region), and the fuel injection amount and the fuel injection amount are set in accordance with the set engine output target value. Various techniques have been proposed to improve the responsiveness to a driver's required output by controlling the amount of intake air to obtain good running performance.

In idle control in an idling operation region, as shown in Japanese Patent Application Laid-Open No. Hei 7-197828, an output torque estimated from an engine speed and a throttle opening and an external load are required for driving at the time of driving. A technique has been proposed in which a target output torque is calculated from a load torque and a throttle opening is controlled from the engine speed and the target output torque.

[0005]

However, the above-described technique is to execute control in accordance with an engine output target value set for each of an idle operation region and a non-idle operation region. Simply combining them lacks continuity of output torque, smoothness and drivability in driving feeling when shifting from the non-idle operation region to the idle operation region or from the idle operation region to the non-idle operation region in the operation region May be impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to ensure continuity of output torque at the time of transition to an operation region between an idle operation region and a non-idle operation region, and to operate the motor. An object of the present invention is to provide an engine control device that improves smoothness and drivability in feeling.

[0007]

In order to solve the above-mentioned problems, an engine control apparatus according to the first aspect of the present invention comprises:
A driver request torque calculating means for calculating a driver request torque required for the engine from the engine speed and the depression amount of the accelerator pedal; and an idle for determining whether the engine operation region is an idle operation region or a non-idle operation region. Determining means, idle control torque calculating means for calculating an idle control torque required to maintain the engine speed at the target idle speed, and an engine operating state from an idle operating region to a non-idle operating region or a non-idle operating region When shifting from the idle operation region to the idle operation region, the correction torque at the time of transition for ensuring the continuity of the output torque between the idle operation region and the non-idle operation region is calculated based on the driver request torque and the idle control torque. Time correction torque calculation means, driver required torque, idle control Torque, comprising a final target torque calculating means for calculating a final target torque to finally output to the engine on the basis of the transitional correction torque, and performs engine control based on the final target torque.

According to this, the final target torque is calculated based on the driver request torque, the idle control torque, and the shift correction torque, so that the final target torque is based on the unified final target torque in all operating regions. Engine control can be performed.

Therefore, continuity of the output torque from the idle operation region to the non-idle operation region or from the non-idle operation region to the idle operation region can be ensured, and the smoothness in the driving feeling can be improved. Also,
A simple and high-performance control system can be constructed, and costs can be reduced.

[0010] In the engine control device according to the second aspect of the present invention, the shift-time correction torque calculating means calculates a basic base torque by adding the driver request torque and the idle control torque, and the basic base torque calculating means. Weighted average torque calculating means for calculating a weighted average torque by weighting the base torque.

In the case where the operating cycle is the first program cycle after shifting from the non-idle operating area to the idle operating area, the basic base when the operating area shifts from the non-idle operating area to the idle operating area is determined. The shift correction torque is calculated by adding the torque and the weighted average torque calculated in the program cycle immediately before the operating region shifts from the idle operation region to the non-idle operation region.

Further, in the second and subsequent program cycles after the operation region shifts from the non-idle operation region to the idle operation region and when the shift-time correction torque exists,
The shift correction torque is calculated by subtracting a preset idle torque reduction value from the existing shift correction torque.

Therefore, the transitional correction torque is set in the first program cycle when the transition from the non-idle operation region to the idle operation region is performed, and is decreased by the idle torque reduction value in each of the subsequent program cycles.

Therefore, when the operation region shifts from the non-idle operation region to the idle operation region, it is possible to prevent the engine stall and the deterioration of the operation feeling due to the rapid decrease of the engine speed, and to smooth the output torque. Connection can be realized.

According to a third aspect of the present invention, in the engine control device, the shift-time correction torque calculating means calculates when the operating region is the first program cycle after shifting from the non-idle operating region to the idle operating region. If the corrected shift torque is larger than the preset upper limit torque value, the shift correction torque is changed to a value equal to the upper limit torque value.

According to this, the shift correction torque in the first program cycle has the upper limit torque value as an upper limit, and is gradually reduced from the upper limit torque value by executing the second and subsequent program cycles. Therefore, the output torque can be reduced at an appropriate speed, and the driving feeling when the operation region shifts from the non-idle operation region to the idle operation region can be improved.

According to a fourth aspect of the present invention, in the engine control device according to the first aspect of the present invention, when the shift correction torque calculating means determines that the shift correction torque exists when the operation region shifts from the idle operation region to the non-idle operation region, The shift correction torque calculated during the program cycle immediately before the operating region shifts from the idle operation region to the non-idle operation region is set as the shift correction torque in the first program cycle.

In the second and subsequent program cycles after the operation region shifts from the idle operation region to the non-idle operation region, and when the transition time correction torque is present, it is preset from the existing transition time correction torque. A new shift correction torque is calculated by subtracting the non-idle torque reduction value.

According to this, when the operating time shifts from the idle operating area to the non-idle operating area, if the shift-time correction torque exists, the shift-time correction torque that exists is the shift-time correction torque in the first program cycle. Since the torque is set, continuity of the output torque can be ensured, and a sense of deceleration before and after the shift from the idle operation region to the non-idle operation region, so-called breathing, can be prevented. Thus, smoothness can be ensured even when the operation region moves between the idle operation region and the non-idle operation region at short intervals.

According to a fifth aspect of the present invention, there is provided the engine control device, wherein the transitional correction torque calculating means sets the non-idle torque reduction value in accordance with the amount of change in the basic base torque. According to this, since the transition correction torque is reduced according to the change amount of the basic base torque, it can be reduced according to the output torque required by the operator who operates the accelerator pedal.

According to a sixth aspect of the present invention, in the engine control apparatus, the idle control torque calculating means sets a basic idle control torque for maintaining the target idle speed, and a target idle speed setting means. Control torque setting means for setting a feedback control torque for feedback-controlling the engine speed to the target idle speed from the rotational deviation between the engine speed and the actual engine speed, and physical conditions such as engine accessories and friction And a torque correction amount setting means for setting a torque correction amount for correcting the consumed torque consumed by the idle control torque, based on the basic idle control torque, the feedback control torque, and the torque correction amount. It is characterized in that it is calculated.

According to this, the idle control torque is calculated based on the basic idle control torque, the feedback control torque, and the torque correction amount, and the basic idle control torque is set according to the operating conditions during the idle operation. The torque is set based on the rotational deviation between the target idle speed and the actual engine speed, and the torque correction amount is set based on the amount of torque consumed by physical conditions such as engine accessories and friction. . Therefore, the engine speed can be quickly and accurately converged to the target idle speed and maintained.

In the engine device according to the present invention, the torque correction amount setting means corrects the known rated output of the engine accessories using the engine speed, so that the torque correction amount is large at the time of low rotation. It is characterized in that a small amount of torque correction is set during high rotation. According to this, the torque correction amount is obtained by correcting a known rated output in advance using the engine speed. For this reason, the torque correction amount can be set according to the characteristics of the correction, and the engine speed during idling can be stabilized.

The engine device according to the present invention corrects the friction torque of the engine, which is set in accordance with the engine speed, based on the engine water temperature, so that the torque correction amount is small at a low speed and at a high speed. It is characterized in that a large torque correction amount is set. According to this, the torque correction amount is obtained by correcting the friction torque using the engine coolant temperature. For this reason, the torque correction amount can be set according to the characteristics of the correction, and the engine speed during idling can be stabilized.

According to a ninth aspect of the present invention, the feedback control torque calculating means calculates a proportional control torque value and an integral control torque value from a rotation deviation between the target idle speed and the actual engine speed, A feedback control torque is obtained based on the calculated proportional control torque value and integrated control torque value.

According to this, the feedback control torque is calculated using the proportional control torque value and the integral control torque value, and the feedback control is performed based on the calculated value. Convergence can be improved.

An engine control device according to a tenth aspect of the present invention is characterized in that the feedback control torque calculating means changes the integral control torque value according to the engine load during idling operation. According to this, it is possible to improve the convergence to the target idle speed after the engine load changes.

According to an eleventh aspect of the present invention, the feedback control torque calculating means learns the integral control torque value when a preset learning condition is satisfied, and converts the learned integral control torque value. It is characterized in that it is used when calculating the feedback control torque. According to this, since the feedback control torque is calculated using the learned integral control torque value, the convergence to the target idle speed can be further improved.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram conceptually showing an engine device provided with an engine control device of the present invention. The engine body 2 used in the engine device 1 is a horizontally opposed engine for an automobile, and is an in-cylinder injection engine that injects fuel directly into a cylinder.
The engine device 1 includes an automatic transmission (not shown).

The engine body 2 is provided with a cylinder block 3 rotatably supporting a crankshaft at a substantially central position thereof, and cylinder heads 4 on both left and right banks of the cylinder block 3. An intake port 5 and an exhaust port 6 are formed in the cylinder head 4, an intake pipe 7 is connected to the intake port 5, and an exhaust pipe 8 is connected to the exhaust port 6.

The intake pipe 7 forms a downstream portion of the intake passage 10, and an air cleaner box 11 and a throttle valve 12 are provided upstream of the intake passage 10. The throttle valve 12 is provided with a throttle actuator 13 that changes the valve opening based on a control signal from an electronic control unit described later.

On the other hand, the exhaust pipe 8 constitutes an upstream portion of the exhaust passage 20, and downstream thereof is a catalytic converter 21 such as a three-way catalyst for purifying exhaust gas, and a muffler 22.
Is provided.

Further, the EGR passage 23 communicates between the exhaust pipe 8 and the gathering portion of the intake pipe 7. The EGR passage 23 is opened / closed by a stepping motor as a driving source in the middle of the EGR passage 23. An EGR valve 24 for changing the area is provided.

The cylinder head 4 is provided with a spark plug 26 and an injector 27 facing the combustion chamber.
The ignition plug 26 forcibly ignites the mixture in the combustion chamber at a predetermined ignition timing by the high voltage supplied through the igniter 28 and the ignition coil 29. The injector 27 is provided with the fuel injection direction toward the piston, atomizes the fuel pumped and supplied from the fuel pump 30 via the fuel pipe, and directly injects the fuel into the combustion chamber.

Then, the engine body 2, the intake passage 10,
The exhaust passage 20 is provided with various sensors for detecting an engine operating state. Specifically, the engine body 2 is provided with a crank angle sensor 31 for detecting the rotation angle of the crankshaft and a water temperature sensor 32 for detecting the temperature of the engine cooling water.

In the intake passage 10, an air flow meter 35 for detecting an intake air amount of the engine, an intake temperature sensor 37 for detecting a gas temperature Tm in the intake pipe 7, and an intake pressure for detecting an intake pressure Pm in the intake pipe 7 are provided. A sensor 38 is provided. The exhaust passage 20 is provided with an exhaust gas temperature sensor 41 for detecting the exhaust gas temperature of the exhaust gas, and an O ₂ sensor 42 for air-fuel ratio feedback control.

An accelerator opening sensor 43 for outputting a voltage signal corresponding to the amount of depression of an accelerator pedal (not shown) is provided for detecting the operating state of the engine. In addition, description of members shown in this drawing that do not directly relate to the function of the present invention will be omitted.

The detection signal from each of the above sensors is
An electronic control unit (hereinafter, simply referred to as an ECU) 50 inputs the drive control signal to each member from the ECU. FIG. 2 is a schematic configuration diagram of the ECU 50. EC
U50 is mainly composed of a microcomputer, and has a CPU 51, a ROM 52, a RAM
53, backup RAM 54, counter / timer 5
5, input port 56 and output port 57 are bus lines 58
Are connected to each other.

Also, an analog signal received from various sensors is converted into a digital signal and delivered to an input port.
A drive circuit 60 for converting a control signal received from an / D converter 59 and an output port into a drive signal and outputting the drive signal to various actuators is provided.

The input port 56 has a crank angle sensor 3
1, the idle switch 44, the selector position switch 46 are connected, an air flow meter 35 via an A / D converter 59, the intake air temperature sensor 37, an exhaust temperature sensor 41, O ₂ sensor 42, an accelerator opening sensor 43, The vehicle speed sensor 45 and the selector position switch 46 are connected.

The idle switch 44 outputs an OFF signal when the accelerator pedal is depressed, and outputs an ON signal when the accelerator pedal is released. The selector position switch 46 determines whether the automatic transmission is in the drive range or the neutral range. Is to be detected. An igniter 28 is connected to the output port, and an injector 27, a throttle actuator 13, and an EGR valve 24 are connected via a drive circuit.

The ROM 52 stores a control program and fixed data set in advance. The RAM 53 stores detection signals from various sensors and the like.
Stores learning data, etc., and stores counters and timers 55
Measures time and the like. The CPU 51 uses a fixed data set in advance and detection signals from various sensors to read ROM data.
Calculation processing is performed in accordance with the control program stored in 52, and fuel injection control, ignition timing control, and the like are performed.

That is, according to the ECU 50 and the sensors and actuators connected to the ECU 50, the driver required torque calculating means M1, the idle control torque calculating means M2, the shift correction torque calculating means M3, and the final target torque calculating means according to the present invention. Each function of M4, idle determination means M5, fuel / intake / EGR setting means M6, and other control functions are realized.

Next, an engine control process executed by the ECU will be described with reference to FIG. Figure 3 shows the EC
It is a control block diagram explaining the control processing part formed in U. The control processing unit includes a driver request torque calculating unit.
M1, idle control torque calculating means M2, shift correction torque calculating means M3, final target torque calculating means M4, idle determining means M5, fuel / intake / EGR setting means M6.

The driver request torque calculation means M1 outputs an output torque (hereinafter referred to as a driver request) required by the driver (vehicle operator) to the engine based on the accelerator opening S which is the depression amount of the accelerator pedal and the engine speed Ne. TEIM is calculated.

The idle control torque calculating means M2 outputs an output torque (hereinafter referred to as idle control torque) required to maintain the engine speed Ne at the target idle speed Nset.
Calculate ISCTQF.

The transition-time correction torque calculating means M3 is necessary for ensuring the continuity of the output torque when the operating state shifts from the idle operation region to the non-idle operation region or from the non-idle operation region to the idle operation region. The output torque (hereinafter referred to as “transition correction torque”) TRKTQ is calculated based on the driver request torque TEIM and the idle control torque ISCTQF.

The idling determining means M5 determines whether or not the engine is idling based on the accelerator opening S and the engine speed Ne.

The final target torque calculating means M4 calculates an output torque (hereinafter referred to as a final target torque) TEI finally output from the engine based on the driver request torque TEIM, the idle control torque ISCTQF, and the shift correction torque TRKTQ. .

The fuel / intake / EGR setting means M6 sets the final target torque TEI, the intake pipe pressure Pm, the intake temperature Tm, and the intake air amount average value Qave based on the final target torque TEI.
Fuel injection amount Gf and intake air amount Q required to output TEI
a, set the EGR amount Qe, and set each control amount to the injector 2
7. Throttle actuator 13, EGR valve 24
Respectively. Incidentally, fuel / intake / EGR setting means
The configuration and internal processing of the M6 are described in detail in Japanese Patent Application Laid-Open No. H11-82100 already filed by the applicant of the present application, and therefore the description thereof will be omitted in the present application.

Next, a method of calculating the final target torque TEI will be described below with reference to a flowchart. FIG.
9 is a flowchart illustrating a final target torque calculation routine. First, in step S1, a driver request torque TEIM is obtained. The driver request torque TEIM is obtained based on the accelerator opening S, which is the amount of depression of the accelerator pedal, and the engine speed Ne. Specifically, the data map is obtained by referring to a data map for calculating the driver required torque preset in the ROM using the accelerator opening S and the engine speed Ne with interpolation calculation.

Next, in steps S2 and S3, the idling control torque ISCTQF and the transition correction torque TRKT
Q is required respectively. The method of calculating the idle control torque ISCTQF and the transition correction torque TRKTQ will be described later. Then, in step S4, a final target torque calculation TEI is obtained. The final target torque calculation TEI is obtained by the following equation (1).

TEI = TEIM + ISCTQF + TRKTQ (1) That is, the final target torque TEI is the driver required torque T
EIM, idle control torque ISCTQF, shift correction torque TRK
It is obtained by adding TQ. Based on the final target torque TEI, the fuel / intake / EGR setting means M6 sets the fuel injection amount Gf, the intake air amount Qa, and the EGR amount Qe, and sets the injector 27, the throttle actuator 1
3. Output a control signal for controlling the EGR valve 24 to each actuator.

Therefore, the engine control is performed based on the unified final target torque TEI for all of the operation regions in the idle operation region and the non-idle operation region. Thereby, continuity of the output torque between the idle operation region and the non-idle operation region can be ensured, and the smoothness in driving feeling can be improved. Also,
A simple and high-performance control system can be constructed, and costs can be reduced.

Next, the idling control torque in step S2
The calculation process of ISCTQF will be described. FIG. 5 is a flowchart showing a routine for calculating the idle control torque ISCTQF. This routine is executed in a program cycle at predetermined intervals.

The idling control torque ISCTQF is calculated in step S
Using the feedback control torque FBKTQ, the basic torque correction amount KGKTQ, the auxiliary device torque correction amount KWBTQ, the other torque correction amount KXTQn during idling, and the idle control torque learning value ISCTQL obtained in step S15 to step S1,
6 is calculated. The idle control torque ISCTQF is calculated by the following equation (2).

ISCTQF = FBKTQ + KGKTQ + KWBTQ + KXTQn + ISCTQL (2) That is, the idle control torque ISCTQF is the feedback control torque FBKTQ, the basic torque correction amount KGKTQ, the auxiliary device torque correction amount KWBTQ, and the other torque correction amount K during idling.
It is obtained by adding XTQn and the idle control torque learning value ISCTQL, respectively.

Here, the basic torque correction amount KGKTQ is obtained by correcting an engine friction torque preset according to the engine speed based on the engine coolant temperature detected by the coolant temperature sensor 32, and is small when the engine speed is low. A large torque correction amount is set for the torque correction amount and the high rotation speed.

The auxiliary equipment torque correction amount KWBTQ is obtained by correcting the known rated output of the engine auxiliary equipment based on the engine speed, and a large torque correction amount at low rotation speed and a small torque correction at high rotation speed. The correction amount is set. And the other torque correction amount KXTQ during idling
n is obtained based on a post-start torque correction amount, a gear position torque correction amount, a learning torque correction amount, and the like.

As described above, these basic torque correction amounts KGKT
Q, the auxiliary equipment torque correction amount KWBTQ, and the other torque correction amount KXTQn during idling are set in accordance with correction characteristics such as output torque or rated output.

The feedback control torque FBKTQ
Is set in accordance with the target idle speed Nset, and the idle control torque learning value ISCTQL is learned in the backup RAM 54 of the ECU 50 when a predetermined learning condition is satisfied, and is read when the engine is started.

FIG. 6 shows the feedback control torque FBKTQ.
Is a calculation routine. This routine is executed in a program cycle at predetermined intervals. First, in step S21, a target idle speed Nset is set. The target idle speed Nset is set according to operating conditions of the engine, for example, a warm-up state. Then, step S22
Then, the rotation deviation DELTAN is calculated using the target idle speed Nset set in step S21 and the actual engine speed Ne directly detected by the crank angle sensor.

In step S23, a proportional control torque value PROEID, which is a proportional component of the feedback control torque FBKTQ, is calculated based on the rotational deviation DELTAN obtained in step S22. The proportional control torque value PROEID is specifically calculated by the following equation (3).

PROEID = IDKPK × IDKP_HL × DELTAN (3) As shown in the above equation (3), the proportional control torque value PROEID
Is obtained by multiplying the rotation deviation DELTAN by a rotation correction coefficient IDKPK and a proportional control torque coefficient IDKP_HL.
The rotation correction coefficient IDKPK and the proportional control torque coefficient IDKP_HL
(Proportional gain) is a value preset in the ROM of the ECU.

Next, in step S24, it is determined whether the feedback control is being performed. Based on this determination, the method of calculating the integral control torque value CFBID, which is the integral of the feedback control torque FBKTQ, is determined. If the feedback control is being performed (YES), the process proceeds to step S25. If the feedback control is not performed (NO), the process proceeds to step S29.

In step S25, an integral control torque value CFBIDI, which is an integral of the feedback control torque FBKTQ, is calculated based on the rotational deviation DELTAN obtained in step S22. Specifically, it is obtained by the following equation (4).

CFBIDI = IDKIK × IDKI_HL × DELTAN × dt (4) As shown in the above equation (4), the integral control torque value CFBIDI
Is obtained by multiplying the rotation deviation DELTAN by a rotation correction coefficient IDKIK and then performing time integration. As a result, hunting of the integral control torque value when the engine speed changes can be prevented.

Then, the process proceeds to step S26 in order to make the integral control torque value CFBIDI obtained by the above equation (4) correspond to the engine load and the engine speed. In step S26, the position of the selector lever (both not shown) of the automatic transmission is in the drive range (D range) or the neutral range (N range).
Is determined by the output of the selector position sensor 46. This is because the load applied to the engine or the engine speed Ne is different between the D range and the N range, and the integral control torque value CFBID is set accordingly.

Here, when the range position of the selector lever is N
If it is in the range (NO), the process proceeds to step S27,
In step S27, N range integral control torque value CFBID_N _n
Is obtained by the following equation (5).

CFBID_N _n = CFBIDI + CFBID_N _n-1 (5) According to the above equation (5), in step S25, the N range obtained in the previous program cycle by the integral control torque value CFBIDI obtained by the equation (4). It is obtained by adding the integral control torque value CFBID_N _n-1 .

[0071] Also, the range position of the selector lever in the step S26 is if a D-range (YES), the process proceeds to step S28, the calculation of the D-range integral control torque value CFBID_D _n is made at step S28. Specifically, it is obtained by the following equation (6).

CFBID_D _n = CFBIDI + CFBID_D _n-1 (6) According to the above equation (6), the D range integral control torque value previously obtained from the integral control torque value CFBIDI obtained by the equation (4) in step S25. It is obtained by adding CFBID_D _n-1 .

As described above, the N range integral control torque value CF
Calculating a BID_N _n and D-range integral control torque value CFBID_D _n, by selecting according to the position of the selector lever, it is possible to improve the convergence to the target engine speed Nset for the engine speed Ne in the feedback control .

If it is determined in step S24 that the feedback control is not being performed (NO), the process proceeds to step S29. In step S29, control for maintaining the previous value of the integral control torque value is performed. In the case of the N range, it is obtained by the following equation (7), and in the case of the D range, it is obtained by the following equation (8).

CFBID_N _n = CFBID_N _n-1 …… (7) CFBID_D _n = CFBID_D _n-1 (8) Thereby, the integrated control torque value CFBID is held during the idle operation open loop control and when the idle switch is turned off. Then, in step S30, a calculation process for obtaining the feedback control torque FBKTQ is performed. The feedback control torque FBKTQ is obtained by the following equation (9).

FBKTQ = PROEID + CFBID (9) As shown in the above equation (9), the feedback control torque FBK
TQ is the proportional control torque value PROE obtained in step S23.
It is obtained by adding the ID and the integral control torque value CFBID obtained in steps S24 to S29.

FIG. 7 shows the idle control torque learning value ISCTQL.
9 is a flowchart showing a learning routine program of FIG. This routine is executed in a program cycle at predetermined intervals. First, in step S31, it is determined whether a learning condition is satisfied. Here, if the learning condition is satisfied (YES), the process proceeds to step S32, and it is determined in step S32 whether the ignition key for starting the engine has been switched from ON to OFF.

Then, when the ignition key is turned from ON to O
If the mode has been switched to FF (YES), the process proceeds to step S33 in order to learn the idle control torque ISCTQL. In step S33, the ignition key is turned from ON to OFF.
Idle control torque learning value when switched to F (hereinafter referred to as integrated switching torque learning value at OFF switching) ISCTQL
X _n is calculated. Specifically, it is obtained by the following equation (10).

ISCTQLX _n = ((CFBID + ISCTQLO) / CTISL) + ISCTQLX _n-1 …… (10) That is, the OFF-switching integral control torque learning value ISCTQLX _n
Is calculated by adding the integral control torque value CFBID and the offset value ISCTQLO of the idle control torque learning value and then dividing by the number of times of learning execution CTISL to obtain the OFF control integral control torque learning value ISCTQLX _n-1 at the time of the previous learning. It is determined by adding. Here, the number of times of learning execution CTISL is a value equal to or less than the set number of times ISLCT, which is incremented by one every time the learning operation is completed.

In step S34, the OFF-switching integral control torque learning value ISCTQLX _n is set to a preset minimum value IS
It is determined whether it is smaller than CTQLXmin. Here, if it is smaller than the minimum value ISCTQLXmin (YES), the process proceeds to step S35, and in step S35, a process of making the OFF-switching integral control torque learning value ISCTQLXn _equal to the above-described minimum value ISCTQLXmin. Then, in order to determine the idling control torque learning value ISCTQL using the OFF changeover integral control torque learned value ISCTQLX _n, the process proceeds to step S38.

If the value is not less than the minimum value (NO),
Proceeds to step S36, whether or not greater than the maximum value ISCTQLXmax to OFF switching time of the integral control torque learning value ISCTQLX _n is set in advance is determined at step S36. Here, when it is larger than the maximum value ISCTQLXmax (YES)
Proceeds to step S37, and is turned off in step S37.
The switching integral control torque learning value ISCTQLX _n is the maximum value IS described above.
Changed to a value equal to CTQLXmax.

In step S36, the maximum value ISCTQLXm
If less than ax (NO), in order determine the idling control torque learning value ISCTQL using the OFF changeover integral control torque learned value ISCTQLX _n, the process proceeds to step S38.

In step S38, it is determined whether the OFF-switching integral control torque learning value ISCTQLX _n is greater than 0, and if it is greater than 0 (YES), step S3 is performed.
The program proceeds to step S39, where an idle control torque learning value ISCTQL is calculated according to a predetermined condition in step S39. Specifically, it is obtained by the following equation (11).

ISCTQL = ISCTQLX _n × TWISL (11) According to this, the integral control torque learning value at the time of OFF switching ISCT
It is obtained by multiplying QLX _n by the correction value TWISL. Here, the correction value TWISL is obtained by referring to a grid table TISLTW preset in the ROM based on the cooling water temperature of the engine detected by the water temperature sensor 32 with interpolation calculation.

If it is determined in step S38 that the value is not larger than 0 (NO), the process proceeds to step S40, in which the idle control torque learning value ISCT is determined in step S40.
QL calculation processing is performed. Specifically, it is obtained by the following equation (12).

ISCTQL = ISCTQLX (12) That is, the integrated control torque learning value ISCTQL at the time of switching at the time of OFF.
_Xn itself is used as the idle control torque learning value ISCTQL. As described above, after the idle control torque learning value ISCTQL is obtained according to the predetermined condition, the process exits from this routine (return).

If the learning condition is not satisfied in step S31 (NO) and if the ignition key is not switched from ON to OFF in step S32 (NO), the idle control torque learning value ISCTQL
This routine is determined not to be performed, and the routine exits (return). Therefore, the idle control torque learning value ISCTQL
Is learned by the above-described learning routine, and is read when the idle control torque ISCTQF is calculated. As described above, in step S16 of FIG.
CTQF is calculated. As a result, the idle control torque IS
By using the idle control torque learning value ISCTQL at the time of CTQF, the convergence of the engine speed to the target idle speed at the time of engine start can be improved.

Next, the process of calculating the transition correction torque TRKTQ performed in step S3 of FIG. 4 will be described. FIG. 8 is a flowchart showing a routine for calculating the transition correction torque TRKTQ, and FIG. 9 is a time chart for explaining the relationship between the basic base torque TEI1 and the transition correction torque TRKTQ. This routine is executed in a predetermined program cycle.

Steps S41 to S51 in FIG. 8 show a calculation process when the operating region shifts from the non-idling operation region to the idle operation region. Step S
At 41, it is determined whether or not the idle switch outputs an ON signal. If the idle switch outputs an ON signal (YES), it is determined that the operation region is within the idle operation region, and step S42 is performed. Proceed to. If the idle switch has output the OFF signal (NO), it is determined that the idle switch is not in the idling operation range, and step S
Go to 52.

In step S42, the current program cycle is the first program cycle after the OFF signal of the idle switch has changed to the ON signal (hereinafter referred to as OFF program cycle).
(Referred to as ON first program cycle). As a result, a new transitional correction torque TRKT
It is determined whether to calculate Q and perform control based on it or to perform control based on the already-set transition correction torque TRKTQ. Here, if it is the OFF / ON first program cycle (YES), the flow shifts to step S43 and subsequent steps to calculate a new shift-time correction torque TRKTQ.

In steps S43 to S45, O
A transition correction torque calculation process is performed in the FF / ON first program cycle. In step S43,
The transitional correction torque TRKTQ is provisionally calculated. The shift correction torque TRKTQ is calculated by the following equation (13) based on the initial basic base torque TEI1 _n and the weighted average torque TEI1_KAV _n-KOLD1 .

TRKTQ = TEI1_KAV _n-KOLD1 -TEI1 _n (13) Here, the initial basic base torque TEI1 _n is a value of the basic base torque TEI1 obtained by adding the driver request torque TEIM and the idle control torque ISCTQF during an OFF / ON initial program cycle. Also, the weighted average torque TEI1_K
AV _n-KOLD1 is obtained by performing a weighted average process on the basic base torque TEI1.

FIG. 9A shows a change in the output signal of the idle switch, and FIG. 9B shows a change in the basic base torque TEI1 and the weighted average torque TEI1_KAV. OFF ・ O
Correction torque at transition during N first program cycle
TRKTQ is, as shown in (a) and (b) in the figure, a weighted average torque TEI1_KAV _n-KOLD1 and an initial basic base torque TEI1 _n
In other words, the difference between the torque before the accelerator pedal is released and the torque after the accelerator pedal is released.

In step S44, it is determined whether or not the transitional correction torque TRKTQ provisionally calculated in step S43 is larger than a preset dashpot torque DASHPOT (upper limit torque value). Here, the temporarily calculated shift correction torque TRKTQ is the dashpot torque DAS.
If it is determined that it is larger than HPOT (YES), the process proceeds to step S45.

In step S45, a process of setting the value of the dashpot torque DASHPOT as a new transition correction torque TRKTQnew is performed (TRKTQnew ← DASHPOT). As a result, the upper limit of the shift correction torque is set.

In step S44, the transitional correction torque TRKTQ temporarily calculated is replaced with the dashpot torque DASHPOT.
If it is determined that the condition is the following (NO), the process exits this routine as it is (return). Therefore, the temporarily calculated correction torque at transition TRKTQ is changed to the new correction torque at transition TRKTQ.
It will be new. As described above, steps S42 to S45
, The shift correction torque TRKTQ at the time of the OFF / ON first program cycle is calculated.

Next, a description will be given of a process of calculating the transition correction torque TRKTQ when the program is not in the OFF / ON first program cycle. If it is determined in step S42 that the current cycle is not the OFF / ON first program cycle (NO),
Current program cycle is idle switch OFF
It is determined that this is a plurality of program cycles since the signal was changed to the ON signal, and the process proceeds to S46 and thereafter to calculate a transitional correction torque TRKTQ corresponding to the program cycle.

In steps S46 to S51, a new transitional correction torque TRKTQnew is set according to various conditions. With this process, the transitional correction torque TRKTQ becomes
The value is gradually reduced from the value set during the OFF / ON first program cycle. FIG. 9C shows the change of the transition correction torque TRKTQ, and FIG. 9D shows the state of the decrease ratio change flag.

First, in step S46, the current shift correction torque TRKTQ is set to a preset cushion value RDASH.
It is determined whether the value is higher than the above. Based on this determination, it is selected whether the reduction speed of the transition correction torque TRKTQ is to be fast or slow.

Here, when the current shift correction torque TRKTQ is a value higher than the cushion value RDASH (YES).
Is a new transitional correction torque TRKTQnew according to the judgment.
The process proceeds to step S47 to set. Step S47
In the processing, a value obtained by reducing the preset first torque reduction value DDSH1 from the current transition correction torque TRKTQ is set as a new transition correction torque TRKTQnew (TRKT
Qnew ← TRKTQ-DDSH1). Then, the process exits from this routine (return).

If the current shift correction torque TRKTQ is equal to or less than the cushion value RDASH in step S46 (NO), the flow advances to step S48 to determine whether or not the decrease change ratio flag is set in step S48. Is determined. The decrease change ratio flag is the transitional correction torque TR
The value for decreasing KTQ (idle torque reduction value) is defined as the first torque reduction value DDSH1 and the second torque reduction value DDSH2 (DDSH1> DDSH).
This flag is used to determine which of 2) is adopted.

The decrease change ratio flag is cleared when the idle switch is turned off, as shown in (d) in the figure, and the engine speed Ne is equal to or less than the value obtained by adding the target engine speed Nset and the engine speed set value Ndash. Is set, or when the vehicle speed V has been equal to or less than the vehicle speed set value VDASH since the transition correction torque TRKTQ became equal to or less than the cushion value RDASH for a set time or longer.

If it is determined in step S48 that the decrease change ratio flag has been set (YES), the flow proceeds to step S49 in order to determine whether the transition correction torque TRKTQ has already disappeared. In step S49, it is determined whether or not the transition correction torque TRKTQ is zero.
Thereby, it is determined whether the transition correction torque TRKTQ set in the OFF / ON first program cycle has already disappeared by the subsequent torque reduction processing. When the transition correction torque TRKTQ is not 0 (NO)
Proceeds to step S50.

In step S50, a preset second torque reduction value DDS is calculated from the current shift correction torque TRKTQ.
A process of updating the value obtained by reducing H2 as a new transition correction torque TRKTQnew is performed (TRKTQnew ← TRKTQ-DDSH
2). Then, the process exits from this routine (return). If the change reduction ratio flag is cleared in step S48 (NO), or if it is determined in step S49 that the transition correction torque TRKTQ is 0 (YES),
Proceed to step S51.

In step S51, a process of updating the current transition correction torque TRKTQ to a new transition correction torque TRKTQnew is performed (TRKTQnew ← TRKTQ). Accordingly, when the change reduction ratio flag is cleared in step S48 (NO), the transition correction torque TRKTQ is maintained at the cushion value RDASH until the flag is set. Also,
If the shift-time correction torque TRKTQ is 0 at step S49 (YES), it is maintained at 0 as it is.

Therefore, when the transition correction torque TRKTQ set during the OFF / ON first program cycle is a value larger than the cushion value RDASH, the reduction is temporarily stopped by the cushion value RDASH in the process of decreasing. After being maintained for a predetermined time at the cushion value RDASH, that is, until the decrease rate flag is set, the value is gradually reduced to zero. As a result, it is possible to prevent the engine rotational speed Ne from dropping below the target idle rotational speed NSET due to a sharp drop in the output torque, and to ensure a smooth change in the output torque. Then, the process exits from this routine (return).

According to the processing from step S42 to step S51 described above, the transitional correction torque TRKTQ is obtained from the amount of torque change before and after the idle switch changes from the OFF signal to the ON signal. TRKTQ is then gradually reduced. As a result, it is possible to avoid engine stall due to a rapid decrease in the engine speed, and to prevent deterioration of the driving feeling.

Next, when the operation region shifts from the idle operation region to the non-idle operation region, the transition correction torque TR
The method of calculating KTQ will be described. In step S41, the idle switch outputs an OFF signal (N
In the case of O), it is determined that the vehicle is not idling, and the process proceeds to step S52. In step S52, the current program cycle is the first program cycle after the ON signal of the idle switch is changed to the OFF signal (hereinafter referred to as O).
N.OFF first program cycle).

If it is the first ON / OFF program cycle (YES), the process proceeds to step S53,
In step S53, it is determined whether or not the transition correction torque TRKTQ is zero. As a result, when the operation region shifts from the idle operation region to the non-idle operation region, the shift correction torque TRKTQ previously set when the operation region shifted from the non-idle operation region to the idle operation region is being reduced. It is determined whether it still exists.

In step S53, the shift correction torque TRKT
If Q is not 0 (NO), it is determined that the previously set transition correction torque TRKTQ is still present, and O
The process proceeds to step S54 in order to calculate the shift correction torque TRKTQ in the N / OFF first program cycle.
In step S54, a process is performed in which the transitional correction torque TRKTQ _n-1 set in the previous program cycle is set as a new transitional correction torque TRKTQ (TRKTQnew ← T
RKTQ _n-1 ).

FIG. 10 shows the basic base torque TEI1 when the accelerator pedal is changed from the non-depressed state to the depressed state.
FIG. 7 is an explanatory diagram for explaining a relationship between the shift correction torque TRKTQ and a transition correction torque TRKTQ. In the figure, (a) shows a change in the output signal of the idle switch, (b) shows a change in the basic base torque TEI1, (c) shows a change in the correction torque TRKTQ during transition, and (d) shows a change in the transitional correction torque TRKTQ. , The change in the third torque reduction value DDSH3.

As shown in FIG. 10 (c), the transitional correction torque TRKTQ changes from the ON signal to the OFF signal at the same time as the idle switch changes from step S5 in FIG.
3. The reduction is temporarily stopped by the processing of S54, and after the value is maintained for a predetermined time, the value is gradually reduced to zero. Thus, a sense of deceleration before and after the change of the idle switch from the ON signal to the OFF signal, that is, so-called breathing, can be prevented, and even when the change from the ON signal to the OFF signal of the idle switch is repeated in a short time. Thus, it is possible to ensure smoothness in driving feeling.

Therefore, the continuity of the output torque in the idle operation region to the non-idle operation region can be ensured, and the drivability can be improved.
Then, the process exits from this routine (return). If it is determined in step S53 that the transition correction torque TRKTQ is 0 (YES), the routine exits from this routine (return).

Then, in step S52, ON / OF
F If it is determined that it is not the first program cycle (N
O): The process proceeds to step S55 and thereafter to calculate the transition correction torque TRKTQ according to the conditions. In step S55, it is determined whether or not the transition correction torque TRKTQ is 0 as in step S53.

Thus, it is determined whether or not the transition correction torque TRKTQ is still present. Here, if the transition correction torque TRKTQ is not 0 (NO), it is determined that the previously set transition correction torque TRKTQ is still present, and the process proceeds to step S56.

In step S56, the shift correction torque TRKTQ _n-1 set in the previous program cycle.
To the third torque reduction value (non-idle torque reduction value) DDSH
A process is performed in which the value obtained by subtracting 3 is used as the new transition correction torque TRKTQ (TRKTQ ← TRKTQ _n−1 −DDSH3). As a result, the transitional correction torque TRKTQ becomes the third torque reduction value DDSH3
It is gradually reduced.

FIG. 11 is a flowchart showing a routine for calculating the third torque reduction value DDSH3. First, step S
At 61, the third torque reduction value DDSH3 is provisionally calculated. Here, the third torque reduction value DDSH3 is obtained by subtracting the basic base torque TEI1 _n-2 in the immediately preceding program cycle from the basic base torque TEI1 _{n-1 in the} previous program cycle (DDSH3
← TEI1 _n-1 -TEI1 _n-2 ).

As a result, the transition correction torque TRKTQ can be set in accordance with the change in the basic base torque TEI1. For example, when the basic base torque TEI1 suddenly increases, the value of the third reduced torque value DDSH3 increases, and the amount of decrease in the transition correction torque TRKTQ increases.

Then, in a step S62, it is determined whether or not the third torque reduction value DDSH3 is 0 or more. Here, if it is 0 or more (YES), the third torque reduction value DDSH3 temporarily calculated in step S61 is adopted as it is, and the routine exits (return). If it is smaller than 0 (NO), the process proceeds to step S63 to limit the minimum value of the third torque reduction value DDSH3. Step S6
In step 3, a process for setting the third torque reduction value DDSH3 to 0 is performed (DDSH3 ← 0).

According to the process of step S56, the transitional correction torque TRKTQ is reduced by using the third torque reduction value set in accordance with the change amount of the basic base torque TEI1, so that the driver requests. The speed can be reduced according to the torque. Therefore, the driving feeling can be improved.

When it is determined in step S52 that the current cycle is not the first ON / OFF program cycle (NO).
As another method of calculating the transition correction torque TRKTQ, the following formula (14) may be used.

TRKTQ _n = TRKTQ _n-1 − (DDSH1 × DDSH3 + DDSH0) (14) According to the above equation (14), the transitional correction torque TRKTQn is _equal to the first correction torque TRKTQn.
It is obtained by multiplying the torque reduction value DDSH1 by the third torque reduction value DDSH3 and further adding a constant DDSH0, and subtracting it from the transition correction torque TRKTQ _n-1 obtained in the previous program cycle. As a result, the method of decreasing the transition correction torque TRKTQ can be optimized, and higher driving feeling smoothness can be secured.

Also, in step S52, ON / OFF
If it is determined that it is not the first program cycle (N
As still another method of calculating the correction torque TRKTQ at the time of the transition O), the first torque reduction value DDSH1 in the above equation (14) is used.
And the constant DDSH0 may be set to a value set for each operating region by the accelerator opening S and the engine speed. Thus, similarly to the other examples described above, the method of reducing the transition correction torque TRKTQ can be further optimized, and a higher driving feeling smoothness can be secured.

If the shift correction torque TRKTQ is 0 at step S55 (YES), the routine exits (return). Therefore, the shift correction torque TRKTQ can be calculated in step S3.

[0125]

As described above, according to the engine control apparatus of the present invention, the final target torque is calculated based on the driver request torque, the idle control torque, and the shift correction torque. In the driving area of
Engine control can be performed based on the unified final target torque.

Therefore, continuity of the output torque from the idle operation region to the non-idle operation region or from the non-idle operation region to the idle operation region can be ensured, and the smoothness of the driving feeling can be improved. Also,
A simple and high-performance control system can be constructed, and costs can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram conceptually showing an engine device provided with an engine control device of the present invention.

FIG. 2 is a schematic configuration diagram of an ECU.

FIG. 3 is a control block diagram illustrating a control processing unit formed in an ECU.

FIG. 4 is a flowchart illustrating a final target torque calculation routine.

FIG. 5 is a flowchart showing a routine for calculating an idle control torque ISCTQF.

FIG. 6 is a flowchart illustrating a routine for calculating a feedback control torque FBKTQ.

FIG. 7 is a flowchart illustrating a routine for calculating an idle control torque learning value ISCTQL.

FIG. 8 is a flowchart showing a routine for calculating a transition correction torque TRKTQ.

FIG. 9: Basic base torque TEI1 and correction torque at transition
FIG. 9 is an explanatory diagram for explaining a relationship of TRKTQ.

FIG. 10 is an explanatory diagram for explaining a relationship between a basic base torque TEI1 and a transition correction torque TRKTQ.

FIG. 11 is a flowchart showing a routine for calculating a third torque reduction value DDSH3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine device 2 Engine main body 14 ETC 24 EGR valve 27 Injector 37 Intake temperature sensor 38 Intake pressure sensor 43 Accelerator opening sensor 44 Idle switch 45 Vehicle speed sensor 46 Selector position switch M1 Driver demand torque calculation means M2 Idle control torque calculation means M3 Transition Time correction torque calculation means M4 Final target torque calculation means M5 Idle determination means M6 Fuel / intake / EGR setting means TEIM driver required torque ISCTQF Idle control torque TRKTQ Transition correction torque FBKTQ Feedback correction torque KGKTQ Basic torque correction amount KWBTQ Auxiliary equipment correction Amount KXTQn Other torque correction amount

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G301 HA04 HA08 HA13 JA04 JA06 KA07 KA14 KA18 LB04 NA02 NA03 NA04 NA06 NA08 NC02 ND02 ND12 ND15 ND22 ND24 NE08 NE17 NE19 NE23 PA10Z PA14Z PD03A PD11Z PE01Z PE03Z PE01ZZZPFZ PFZ PFZ PF16Z

Claims (11)

[Claims] 1. A driver request torque calculating means for calculating a driver request torque required of an engine from an engine speed and an accelerator pedal depression amount, and an engine operation region is an idle operation region or a non-idle operation region. Idle determination means for determining whether the engine speed is the idle control torque required to maintain the engine speed at the target idle speed; and Alternatively, when shifting from the non-idle operation region to the idle operation region, the shift correction torque for ensuring the continuity of the output torque between the idle operation region and the non-idle operation region is changed to the driver request torque and the idle control torque. Shift correction torque calculating means for calculating based on the And a final target torque calculating means for calculating a final target torque to be finally output to the engine based on the torque, the idle control torque, and the correction torque at the time of transition. Engine control device. 2. The shifting correction torque calculating means includes: a basic base torque calculating means for obtaining a basic base torque by adding the driver request torque and the idle control torque; and a weighted average of the basic base torque. A weighted average torque calculating means for calculating an average torque, wherein when the operation region is the first program cycle after shifting from the non-idle operation region to the idle operation region, the operation region is changed from the non-idle operation region to the idle The correction torque at the time of transition is calculated by adding the basic base torque at the time of transition to the operation region and the weighted average torque calculated during the program cycle immediately before the operation region transitions from the idle operation region to the non-idle operation region. The second and subsequent processes after the operating area shifts from the non-idle operating area to the idle operating area. In the case of a gram cycle and a transitional correction torque is present, a new transitional correction torque is calculated by subtracting a preset idle torque reduction value from the existing transitional correction torque. The engine control device according to claim 1. 3. The shift-time correction torque calculating means sets a shift-time correction torque in a case where the shift time is the first program cycle after the shift from the non-idle operation range to the idle operation range. 3. The engine control device according to claim 1, wherein when the torque is larger than the upper limit torque value, the shift correction torque is changed to a value equal to the upper limit torque value. 4. 4. The shift-time correction torque calculating means, when the shift-time correction torque is present when the operation region shifts from the idle operation region to the non-idle operation region, changes the operation region from the idle operation region to the non-idle operation. The shift correction torque calculated during the program cycle immediately before the shift to the area is set as the shift correction torque for the first program cycle, and the second and subsequent programs after the operation area shifts from the idle operation area to the non-idle operation area In a cycle and when a transitional correction torque exists, a new transitional correction torque is calculated by subtracting a preset non-idle torque reduction value from the existing transitional correction torque. The engine control device according to claim 1. 5. The engine control device according to claim 4, wherein the shift-time correction torque calculating means sets the non-idle torque reduction value according to a change amount of a basic base torque. 6. An idle control torque calculating means, comprising: a basic idle control torque setting means for setting a basic idle control torque for maintaining the target idle speed; a target idle speed and an actual engine speed. Feedback control torque setting means for setting a feedback control torque for performing feedback control of the engine speed to the target idle speed from the rotational deviation of the engine, and a torque correction amount for correcting an output torque consumed during idling operation Torque correction amount setting means to be set;
The engine control device according to any one of claims 1 to 5, further comprising: calculating an idle control torque based on the basic idle control torque, the feedback control torque, and the torque correction amount. 7. The torque correction amount setting means corrects the known rated output of the engine accessories based on the engine speed to thereby provide a large torque correction amount at a low rotation speed and a small torque correction amount at a high rotation speed. The engine control device according to claim 6, wherein the setting is performed. 8. The torque correction amount setting means corrects the friction torque of the engine set according to the engine speed based on the engine coolant temperature, so that the torque correction amount is small at a low speed and large at a high speed. 7. The correction amount is set.
Or the engine control device according to 7. 9. The feedback control torque calculating means calculates a proportional control torque value and an integral control torque value from a rotation deviation between the target idle speed and an actual engine speed, and calculates the proportional control torque value and the integrated control torque value. The engine control device according to any one of claims 6 to 8, wherein the feedback control torque is obtained based on the integrated control torque value. 10. The engine control device according to claim 9, wherein the feedback control torque calculation means changes the integral control torque value according to an engine load during idling operation. 11. The feedback control torque calculating means learns the integral control torque value when a preset learning condition is satisfied, and calculates the feedback control torque using the learned integral control torque value. The engine control device according to claim 9 or 10, wherein: