JP2002256959A - Control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and inexpensively compensate for fluctuation of torque output due to a change in air density in a throttle control for a vehicle engine. SOLUTION: According to the accelerator opening and the rotational frequency, a basic engine torque command value tTe is calculated by a first map m1. According to the intake air quantity (mass flow) and the rotational frequency, an engine torque estimated value eTe is calculated by a second map m2. According to the dissociation amount of the engine torque estimated value eTe to the basic engine torque command value tTe, the basic engine torque command value tTe is corrected, and according to the corrected command value, a throttle opening command value is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an engine, and more particularly, to an engine mounted on a vehicle, which reflects air density, which changes according to changes in atmospheric pressure and temperature, in throttle control. To achieve a target engine torque with high accuracy.

[0002]

2. Description of the Related Art Conventionally, a throttle opening target value is set based on an engine torque command value corresponding to an operating condition, and this opening target value is achieved by an electronically controlled throttle valve (Japanese Patent Application Laid-Open No. Hei 9 (1999)). -287507). Here, when the vehicle travels on highland or hot ground, the density of the intake air decreases, so that the engine torque obtained at a constant throttle opening and the engine speed decreases.
As a countermeasure, the above-mentioned prior art detects the atmospheric pressure and the intake air temperature, and corrects the target throttle opening value (target opening area) with various correction coefficients relating to the atmospheric pressure and the air temperature, thereby preventing a decrease in engine torque. Is disclosed.

[0003]

However, in this case, it is necessary to provide a special sensor for detecting the atmospheric pressure and the intake air temperature for each parameter, which inevitably increases the cost. Further, both a correction coefficient map relating to atmospheric pressure and a correction coefficient map relating to air temperature are required (an individual correction coefficient calculation map is required for each parameter), and the configuration of the control system is complicated.

Further, since the rate of change of the engine torque and the rate of change of the throttle opening (opening area) are non-linear, uniform correction using a uniform correction coefficient cannot be performed over the entire operating range (operating). The effect of correction differs depending on the area). In view of such circumstances, an object of the present invention is to enable a change in air density to be reflected in control of an engine and its related devices, in particular, throttle control, with a simple configuration without increasing costs. I do. It is another object of the present invention to easily realize this by using a correction coefficient that can be universally applied over the entire operation range.

[0005]

According to a first aspect of the present invention, there is provided a control apparatus for an engine based on a mass measuring air flow sensor and an intake air amount detected by the air flow sensor. An engine torque estimated value calculating means for calculating an engine torque estimated value; an engine torque estimated value calculated by the engine torque estimated value calculating means;
Control parameter correction means for correcting the control parameters of the engine or its related devices based on the amount of deviation from the target engine torque based on the operating conditions.

According to a second aspect of the present invention, there is provided an engine control device, comprising: an electronically controlled throttle valve; and an engine torque command value calculation device for calculating an engine torque command value based on a driver's intention. And a throttle opening command value calculating means for calculating a throttle opening command value based on the engine torque command value calculated by the engine torque command value calculating means. A measuring airflow sensor, an engine torque estimated value calculating means for calculating an engine torque estimated value based on an intake air amount detected by the airflow sensor, an engine torque estimated value calculated by the engine torque estimated value calculating means, A throttle opening command value adjusting means for adjusting the throttle opening command value based on the engine torque command value; When, characterized in that the provided.

The throttle opening command value adjusting means calculates a divergence amount between the estimated engine torque value and the engine torque command value, and calculates the engine torque based on the divergence amount. Preferably, the throttle opening command value is adjusted by correcting the command value. In this case, the throttle opening command value adjusting means may be configured as follows.
As described in above, a ratio between the estimated engine torque value and the engine torque command value may be obtained as the deviation amount, and a correction rate based on the ratio may be multiplied by the engine torque command value.

Preferably, the correction rate of the engine torque command value is limited to a predetermined upper limit or less. Here, the upper limit value may be equal to or less than the ratio of the engine torque when the throttle is fully open to the engine torque when the throttle is half open.

According to a seventh aspect of the present invention, the correction rate of the engine torque is set to 1 according to characteristics required for the engine.
It is preferable to limit to the above. In a specific embodiment of the present invention, as set forth in claim 8, the throttle opening command value adjusting means is based on a first map in which an engine torque is allocated according to an engine speed and a throttle opening. The throttle opening command value is calculated by the calculation, and the engine torque estimation value calculation means allocates the engine torque according to the engine speed and the intake air amount under the same pressure and the same temperature as the first map. The engine torque estimated value is calculated based on a second map.

It is preferable that the throttle opening command value adjusting means corrects the engine torque command value by including an integral operation based on the divergence amount. 2. The throttle opening command value adjusting means according to claim 1, wherein a rate of change of a correction value of the engine torque command value is determined.
It is preferable to limit it to a predetermined range as described in 0.
Here, the “change rate of the correction value of the engine torque command value” is a change amount per control cycle of the correction value of the engine torque command value. In the specific embodiment of the present invention, the “correction value” here is synonymous with “the correction rate of the engine torque command value”.

In the throttle opening command value adjusting means, the rate of change of the correction value of the engine torque command value is determined by:
It may be a constant as described in claim 11. The engine control device according to the present invention further includes a throttle opening detection unit that detects a throttle opening and a cooling water temperature detection unit that detects a cooling water temperature of the engine. Wherein the throttle opening command value adjusting means detects that the throttle opening detected by the throttle opening detecting means is smaller than a predetermined opening or the cooling water temperature detected by the cooling water temperature detecting means is a predetermined temperature. If it is lower, the rate of change of the correction value of the engine torque command value is preferably set to zero.

According to a thirteenth aspect of the present invention, the throttle opening command value adjusting means performs a delay process on the engine torque command value calculated by the engine torque command value calculating means. The throttle opening adjustment value may be adjusted based on the value calculated as a result and the engine torque estimated value. In the engine control device according to the present invention, as set forth in claim 14, the throttle opening command value adjusting means includes a backup memory that retains the stored information even after the ignition switch is turned off. Is preferred.

[0013]

According to the first aspect of the present invention, the following effects can be obtained. When the air density decreases due to a decrease in the atmospheric pressure, an increase in the temperature, or the like, the intake density decreases accordingly, so that the intake air amount (mass flow rate) per the same volume flow rate decreases. Conversely, when the air density increases, the intake air amount increases.

Here, the estimated engine torque value according to the present invention is calculated based on the intake air amount detected by the mass weighing type air flow sensor. Therefore, the estimated engine torque value corresponds to an actual engine torque that changes according to a change in the air density. Further, the correction of the control parameter (in the specific embodiment, the engine torque command value) according to the present invention is calculated based on the engine torque estimated value that changes according to the change in the air density and the operating condition as described above. Target engine torque.
Therefore, the correction of the control parameters reflects the shortage (or excess) due to the change in the air density with respect to the engine torque based on the operating conditions.

Therefore, according to the present invention, a change in air density is compensated for in a control parameter of the engine or its related equipment. Therefore, even in an operation in a highland, a hotland, or a cold region, it is possible to obtain the same operability as in the standard condition (generally, the pressure and the standard temperature corresponding to the lowland). In addition, the present invention utilizes a mass weighing type air flow sensor normally provided for fuel injection control in engine control, and this air flow sensor can be used to change the air density due to a change in air pressure, and also to change the air density due to a change in air temperature. Can respond to changes in

Therefore, according to the present invention, there is no need to add a special sensor such as an atmospheric pressure sensor or an intake air temperature sensor, which is economical. Further, since it is not necessary to set the correction coefficient of the throttle opening command value for each parameter such as the atmospheric pressure and the temperature, the configuration can be simplified. According to the second aspect of the present invention, the throttle opening command value adjusted by the throttle opening command value adjusting means according to the present invention is such that the change in air density is compensated. For this reason, even when operating in high altitude, hot or cold area,
Torque output characteristics equivalent to those under standard conditions can be obtained.

According to the third aspect of the invention, the adjustment of the throttle opening command value is not based on the correction of the throttle opening command value calculated based on the engine torque command value, but on the basis of the engine torque command value. The correction is performed. Here, the decrease in the air density and the decrease in the engine torque are in a linear relationship. On the other hand, the change rate of the throttle opening and the change rate of the engine torque have a non-linear relationship that the change rate of the engine torque changes for each absolute value of the throttle opening. Therefore, in the case of correcting the throttle opening command value, it is necessary to take measures such as setting a correction coefficient for each throttle opening in order to compensate for this nonlinearity.

Therefore, if a configuration in which the engine torque command value is corrected when adjusting the throttle opening command value as in the present invention is adopted, such troublesomeness can be eliminated and the configuration can be simplified. According to the invention described in claim 4, the throttle opening command value is set based on the linear relationship between the decrease in air density and the decrease in engine torque.
Can be adjusted very easily. That is, the engine torque decreases at the same rate in the entire region corresponding to the throttle opening and the engine speed according to the change (for example, decrease) of the air density. Therefore, if the air density is constant in any part of this area, by multiplying the engine torque command value by the same correction rate,
The throttle opening command value can be adjusted.

According to the invention described in claim 5, the following effects can be obtained. The present invention, even under the same operating conditions,
At the time of operation in high altitude or hot terrain, by increasing the throttle opening, it is intended to obtain torque output characteristics equivalent to those under standard conditions. It is also possible to multiply the engine torque command value by the total decrease in air density, and as a result of adjusting the throttle opening command value, the throttle opening may reach the full opening. In such a case, even if the accelerator is further depressed, a torque dead zone in which the engine torque does not increase any more is formed. If the torque dead zone is large, the driver feels strange.

Therefore, by providing an upper limit to the correction rate of the engine torque command value, if the engine torque is greatly reduced, it is not possible to compensate for all of the reduced amount, but excessive expansion of the torque dead zone is suppressed. As a result, discomfort to the driver can be reduced. According to the sixth aspect of the present invention, even when the correction of the engine torque command value is maximized, the torque dead zone can be suppressed to about half of the throttle valve movable range. For this reason,
The engine torque can be adjusted within a relatively wide range until the accelerator is depressed by about half, so that the driver does not feel uncomfortable.

According to the seventh aspect of the invention, even if the air density increases in a cold region or the like, the correction of the engine torque command value does not work on the output suppression side. Therefore, in a vehicle in which the power performance is to be emphasized, the power performance of the engine can be utilized to the maximum. Claim 8
According to the invention described in (1), the total performance torque measurement for creating the first map and the total performance torque measurement for creating the second map can be performed in parallel. For this reason, it is possible to suppress an increase in the number of working steps for constructing the adjustment control system for the throttle opening command value.

According to the ninth aspect of the present invention, the engine torque command value is corrected by including the integral operation based on the deviation amount of the engine torque estimated value, so that the engine torque command value matches the engine torque command value. Thus, the decrease in the air density can be compensated for. According to the tenth aspect of the present invention, even if the air flow sensor fails and its detection signal suddenly changes, it is possible to easily prevent an excessive change in the throttle opening command value by the adjustment according to the present invention, A sudden change in engine torque can be prevented.

Further, the control for this purpose only limits the rate of change of the correction value of the engine torque command value within a predetermined range, and can be easily added. Fail safe is easily and inexpensively compensated. Further, when the accelerator operation amount is largely changed, a large deviation occurs between the estimated engine torque value and the engine torque command value due to a transient response of the engine. In addition, the throttle opening command value may fluctuate finely as a result of the adjustment, for example, by picking up noise of the airflow sensor signal. Then, there is a possibility that the throttle valve moves other than the original movement and gives a sense of incongruity to the driver.

According to the present invention, by restricting the rate of change of the correction value of the engine torque command value to a predetermined range, unnecessary movement of the throttle valve can be easily suppressed in response to the change in the operating conditions or noise. In addition, discomfort to the driver can be reduced. According to the eleventh aspect, it is possible to realize a fail-safe against a failure of the air flow sensor, and suppression of unnecessary movement of the throttle valve based on a change in operating conditions or noise due to an extremely simple configuration.

According to the twelfth aspect, the rate of change becomes zero at a low throttle opening where the detection accuracy of the airflow sensor decreases and the error in the estimated engine torque value tends to increase. In addition, the error in the estimated engine torque value tends to be large even at low temperatures due to the effects of friction, correction of the injection amount at the time of cold operation, unstable combustion, and the like.

Therefore, according to the present invention, it is possible to prevent an incorrect adjustment of the throttle opening command value based on the estimated engine torque value including a large error. According to the thirteenth aspect, a delay process is performed on the engine torque command value when adjusting the throttle opening command value, and the delay required for the response of the intake system and the detection of the airflow sensor is reflected. Thereby, the throttle opening command value can be adjusted accurately.

According to the fourteenth aspect, information relating to adjustment of the throttle opening command value when the ignition (IGN) switch is turned off is stored in the backup memory. Then, when the IGN switch is turned on next, the stored information is used as initial information. As a result, it is not necessary to make the related information correspond to the current air density from the standard condition, and the adjustment of the throttle opening command value can be started immediately.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
1 schematically shows a hardware configuration of a control device of an engine 1 according to the embodiment. As shown in FIG. 1, a hot-wire type air flow meter 31 is attached to the intake passage 2 of the engine 1 downstream of an air cleaner (not shown).
An electronically-controlled throttle valve 3 is arranged further downstream.

The air flow meter 31 measures the mass flow rate of the intake air, and is an embodiment of a mass measuring air flow sensor according to the present invention. As the airflow sensor, a hot-film sensor or the like can be employed in addition to the hot-wire sensor. The throttle valve 3 is controlled by a command signal from an electronic control unit (hereinafter referred to as “ECU”) 21.

The ECU 21 has an IGN as a storage device.
(Ignition) The backup memory 2 in which stored information is not cleared even after the switch 41 is turned off.
3 is provided. The accelerator opening APO as an accelerator operation amount representing the driver's intention is input from the accelerator opening sensor 32 to the ECU 21 as operating conditions. In addition, as the operating state of the engine 1, the air flow meter 3
1, the intake air amount Qa, the throttle opening degree TVO from the throttle opening degree sensor 33, and the engine speed sensor 34
, The engine speed Ne and the coolant temperature (hereinafter referred to as “water temperature”) Tw from the water temperature sensor 35 are input. In addition,
The throttle opening sensor 33 constitutes a throttle opening detecting means according to the present invention, and the water temperature sensor 35 constitutes a cooling water temperature detecting means according to the present invention.

Then, the ECU 21 controls the throttle valve 3 based on these various control information. Next, EC
FIG. 2 shows the software configuration and functions of U21.
This will be described with reference to FIG. The ECU 21 has a first storage in the storage device.
And the second map m2 are stored.

The first map m1 constitutes the engine torque command value calculating means according to the present invention, and is obtained by measuring the total performance torque measured under standard conditions (atmospheric pressure and standard temperature corresponding to lowland). It was created based on. Specifically, as shown in FIG. 3, the engine torque Te is allocated according to the engine speed Ne and the throttle opening TVO.

The ECU 21 determines the engine speed Ne and the accelerator opening AP (instead of the throttle opening TVO).
Read O. Then, referring to the first map m1 based on the control information, the engine torque corresponding to the current engine speed Ne and the accelerator opening APO is calculated as the basic engine torque command value tTe. The basic engine torque command value tTe is input to a filter processing unit 101 and a multiplication unit 102 described later.

On the other hand, the second map m2 constitutes an engine torque estimated value calculating means according to the present invention.
The first map m1 corresponds to a map in which the intake air amount Qa under standard conditions is used as a parameter instead of the throttle opening TVO. The data for creating the second map m2 was measured in the course of the engine control construction work in parallel with the measurement work for creating the first map m1. Specifically, as shown in FIG. 4, the engine torque Te is allocated according to the engine speed Ne and the intake air amount Qa.

The ECU 21 reads the engine speed Ne and the intake air amount Qa. Then, an engine torque corresponding to the current engine speed Ne and the intake air amount Qa is calculated by referring to the second map m2 based on the control information. The calculated torque value is input as an engine torque estimated value eTe to a divider 103 described later. The filter processing unit 101 delays the basic engine torque command value tTe by a known first-order delay process or a dead time process. Here, with respect to the basic engine torque command value tTe, the delay in the throttle control and the change in the intake air amount accompanying the throttle control, and the air flow meter 31
Is delayed. When the changing speed of the engine torque correction value (μ) described later is made sufficiently small, the filter processing unit 101 can be omitted. Engine torque command value tTe 'after filtering
Is input to the next division unit 103.

The dividing unit 103 receives the filtered engine torque command value tTe ′ and the estimated engine torque value eTe calculated with reference to the second map m2. Then, a value obtained by dividing the estimated engine torque value eTe by the engine torque command value tTe ′ is input to the engine torque correction rate calculation unit 104 as an engine torque change rate dT (= eTe / tTe ′). Note that the engine torque change rate dT corresponds to the deviation amount according to the present invention.

The engine torque correction rate calculator 104 can communicate with the backup memory 23 mutually. For the engine torque correction rate calculation unit 104, the engine 1
Is in a predetermined operating state, a correction value update prohibition command is generated, and a correction upper limit L1 and a correction lower limit L2 are set. The correction value update prohibition command is issued by the correction value update prohibition condition setting unit 105 when the throttle opening TVO is smaller than the predetermined opening or the water temperature Tw is lower than the predetermined temperature.

The engine torque correction rate calculation unit 104 calculates an engine torque correction rate μ falling within the range from the correction lower limit value L2 to the correction upper limit value L1 according to a flowchart (FIG. 5 or 9) described later, and calculates the calculation result. It is stored in the backup memory 23 as needed. Here, the engine torque correction rate calculation unit 104 sets the correction value update prohibition condition setting unit 1
If the correction value update prohibition command has been issued from step 05, the engine torque correction rate μ is not updated, but the one calculated in the previous calculation is output. The engine torque correction rate μ is input to the following multiplication unit 102. In the present embodiment, the engine torque correction rate μ is synonymous with “correction value of basic engine torque command value tTe”.

The multiplier 102 receives the basic engine torque command value tTe and the engine torque correction rate μ.
The multiplier 102 multiplies the value (= tTe × μ) calculated by multiplying these input values by the corrected engine torque command value aT
e is input to the first map m1. As described above, the backup memory 23, the filter processing unit 101, the multiplication unit 102, the division unit 103, and the engine torque correction rate calculation unit 1
04 and the correction value update prohibition condition setting unit 105 constitute a throttle opening command value adjusting means according to the present invention.

The corrected engine torque command value aTe is thereafter input again to the first map m1. At this time,
The engine speed Ne is also input. Then, based on these input values, the throttle opening command value d is obtained by inverse conversion.
Calculate TVO. The first map m1 referred to at the time of the reverse conversion constitutes a throttle opening command value calculating means according to the present invention.

Then, the ECU 21 outputs an operation amount based on a deviation between the throttle opening command value dTVO and the actual throttle opening (throttle opening sensor output) TVO by a known feedback control so that the throttle valve 3 Control the opening. Here, a method of calculating the throttle opening command value dTVO using the first map m1 and the second map m2 will be described in detail.

Generally, the total performance torque of an engine is measured under standard conditions. The engine torque, the engine speed, the throttle opening, and the intake air amount (the value detected by the air flow sensor) measured at this time have a unique relationship. That is, under standard conditions, if the engine torque and the engine speed are constant, the throttle opening and the intake air amount correspond in a one-to-one relationship.

Here, a first map m1 and a second map m2 are created based on the above-mentioned total performance torque measurement data. Then, it is assumed that the throttle valve 3 is controlled by the throttle opening command value dTVO obtained by referring to the first map m1 based on the basic engine torque command value tTe. Then, the estimated engine torque eTe obtained by referring to the second map m2 based on the amount of intake air at the throttle opening at this time normally matches the basic engine torque command value tTe. Becomes

However, when the air density decreases at a high altitude or the like, the detection value Qa per unit volume flow rate of the mass measuring type air flow sensor 31 decreases as compared with the standard condition. Then, the engine torque estimated value eTe decreases to correspond to this, and the basic engine torque command value t
It becomes lower than Te. According to the invention, the second map m
2 is reduced (= dT) of the engine torque estimated value eTe obtained with reference to the basic engine torque command value tTe.
Is reflected in the correction of the basic engine torque command value tTe as a decrease in the air density. Then, the throttle opening command value dTVO is obtained based on the corrected engine torque command value aTe with reference to the first map m1. For this reason, the throttle opening command value dTVO can compensate for the decrease in the air density.

By adopting such a configuration, the total performance torque measurement for creating the first map m1 and the total performance torque measurement for creating the second map m2 are performed in parallel. Thus, it is possible to suppress an increase in the number of work steps for constructing a control system for adjusting the throttle opening command value (correcting the engine torque command value). Next, an engine torque correction rate calculation routine will be described.

FIG. 5 is a flowchart of an engine torque correction rate calculation routine according to this embodiment. In S (step) 1, it is determined whether a correction value update condition is satisfied. Here, if the correction value update prohibition command is not issued by the correction value update prohibition condition setting unit 105, it is determined that the update condition is satisfied, and the process proceeds to S2. On the other hand, if the correction value update prohibition command has been issued, it is determined that the update condition is not satisfied, and the routine returns. Therefore, in this routine, the change amount of the engine torque correction rate μ is set to 0, and the previously calculated engine torque correction rate μn-1 is maintained.

In S2, the engine torque change rate dT is 1
It is determined whether it is smaller than 00-α (%). Here, α is for setting a dead zone for the fluctuation of the estimated engine torque value, and by setting it to 2 to 3%, execution of the calculation due to the fluctuation of the change rate dT based on the error is prevented. . Engine torque change rate dT is 100
If it is smaller than -α (%), the process proceeds to S3, while
If the engine torque change rate dT is 100-α (%) or more, the process proceeds to S5.

In S3, an update width β of the engine torque correction rate μ is calculated. Here, the update width β is calculated by multiplying a value obtained by subtracting the engine torque change rate dT from 1 by a coefficient (gain) K (β = K × (1−dT)). However, by setting the upper limit value βmax as a limiter, the amount of change in the engine torque correction rate μ per control cycle (that is, the update width β) is suppressed to the upper limit value βmax or less. The upper limit value βmax is, for example, when the engine torque correction rate μ is 1 (100%: no correction) to 1.2 (120%).
Is set to a value that takes about 5 minutes to reach. The update width β corresponds to the rate of change of the correction value of the engine torque command value according to the present invention.

In S4, the engine torque correction rate μ is updated by adding the update width β to the previous value μn−1 of the engine torque correction rate. On the other hand, in S5, it is determined whether or not the engine torque change rate dT is greater than 100 + α (%). Here, α has the same value as the above α, and forms a dead zone against fluctuations in the estimated engine torque value. If the engine torque change rate dT is greater than 100 + α (%), the process proceeds to S6, while the engine torque change rate dT is 1
If it is less than 00 + α (%), the process proceeds to S8.

In S6, an update width β of the engine torque correction rate μ is calculated. The update width β here is also calculated in the same manner as described above (β = K × (1−dT)). However, by setting the lower limit βmin (βmin <0) as the limiter, the amount of change in the engine torque correction rate μ per control cycle (that is, the update width β) is limited to the lower limit βmin or more. This allows you to move to cold regions,
Even when the estimated engine torque eTe becomes considerably large, the throttle opening TVO is reliably reduced. The lower limit value βmin is, for example, such that the engine torque correction rate μ is 1.
It takes about 5 minutes to return from 2 (120%) to 1 (100%: no correction) (βmax = −βmi)
n).

In S7, the engine torque correction rate μ is updated by adding the update width β to the previous value μn−1 of the engine torque correction rate. As described above, the engine torque correction rate calculation routine calculates the engine torque correction rate μ calculated last time.
It is configured to include an integration operation of adding the update width β to n−1.

Then, the calculated engine torque correction rate μ
Is stored in the backup memory 23 as needed. As described above, the stored correction factor μ is not cleared even after the IGN switch 41 is turned off. Then, when the IGN switch 41 is turned on next, the correction of the basic engine torque command value tTe is started immediately using the correction factor μ stored immediately before the switch is turned off as an initial value.

If the ECU 21 is constructed without such a backup memory, the IGN switch 4
Every time 1 is added, it is necessary to update the engine torque correction factor μ to correspond to the current air density. Then, when the correction rate μ is calculated including the integration operation or when the update width β is limited as described above, it takes a considerable time to deal with the current state, and the time when the correction does not function effectively is required. Is prolonged. Further, when the correction value update prohibition condition is set, each time the update is prohibited, the response is delayed, and the time during which the correction does not function effectively becomes longer.

It should be noted that geographical conditions related to air density, such as highlands and hot lands, are not conditions to be corrected unless the vehicle moves. For this reason, the engine torque correction factor μ stored in the backup memory 23 can be used as a highly reliable one unless the vehicle geographically moves after the IGN switch 41 is turned off and before the next start. .

By the way, it is assumed that a simple method of calculating the engine torque correction rate μ only by a proportional operation with respect to the control target value 100% is adopted. In this case, the engine torque correction rate μT decreases as the engine torque change rate dT approaches 1 due to the correction. Therefore, the engine torque change rate dT is returned to 1 (the basic engine torque command value t
Te).

Returning to the description of the flowchart, in S8, it is determined whether or not the engine torque correction rate μ is larger than the correction upper limit L1. Here, the correction upper limit L1 is provided as a limiter for the engine torque correction rate μ. The engine torque correction rate μ is equal to the correction upper limit L
When it is determined that the value is greater than 1, the process proceeds to S9. On the other hand, when it is determined that the engine torque correction rate μ is equal to or less than the correction upper limit L1, the process proceeds to S10.

In S9, the engine torque correction rate μ is set to the correction upper limit L1. Here, the limitation of the engine torque correction rate μ by the correction upper limit L1 will be described in detail.
If the engine torque correction factor μ is not provided with an upper limiter and can be increased without limit, this will be too large, and the throttle opening will reach the full opening even if the accelerator is depressed a little. Things happen. In this case, a torque dead zone in which the throttle opening is not increased even if the accelerator is further depressed is formed in a wide range, giving the driver an uncomfortable feeling.

This will be further described with reference to FIG. FIG. 6A shows a change with time of the accelerator opening APO when the accelerator is depressed from the fully closed position to the fully opened position. FIG. 6B shows the case where the basic engine torque command value tTe is not corrected (broken line), the case where the correction rate μ is suppressed small (dashed line), and the throttle opening TVO at the time when each accelerator opening is reached. The case where the correction factor μ can be set large (solid line) is shown.

First, when no correction is made, the throttle valve 3 opens following the accelerator operation. On the other hand, it is assumed that the correction is made smaller. Here, the throttle valve 3
Is driven slightly larger than the accelerator operation. As a result, the accelerator is fully opened at the position (B) before reaching the fully open position. Therefore, a torque dead zone is formed in a range where the accelerator opening APO ranges from B to full opening.

On the other hand, it is assumed that the correction is made to function largely. Here, the throttle valve 3 is driven very large in response to the accelerator operation. As a result, the vehicle is fully opened at the position (A) shortly after the start of the accelerator operation. Therefore, a wide range of the accelerator opening APO from A to the full opening is a torque dead zone. Accordingly, in the present embodiment, the correction upper limit L1 is set, and the value is set to be equal to or less than the ratio TA / TB of the engine torque TA in the fully opened state of the throttle valve 3 to the engine torque TB in the half open state of the throttle valve 3 ( (See FIG. 7). Specifically, the correction upper limit L1 is set to 1.2 (120%).

This effect will be described with reference to FIG. FIG.
6 shows changes over time of the accelerator opening APO and the throttle opening TVO, as in FIG. According to the above setting, even if the accelerator is fully depressed to the fully open position, the throttle valve 3 is opened at an accelerator opening that is equal to or greater than the accelerator opening at which the throttle valve 3 is half-opened without correction, even if the accelerator is fully depressed. It can be fully opened. That is, since the torque dead zone is suppressed to half or less of the accelerator movable range, it is possible to reduce a sense of discomfort to the driver.

Returning to the description of the flowchart, in S10, it is determined whether or not the engine torque correction rate μ is smaller than the correction lower limit L2. Here, the correction lower-limit value L2 is provided as a limiter for the engine torque correction rate μ together with the upper-limit value L1. The correction lower limit L2 is set to 1 (100%) or a value less than 1 according to the characteristics of the vehicle.
When it is determined that the engine torque correction rate μ is smaller than the correction lower limit L2, the process proceeds to S11. On the other hand, when it is determined that the engine torque correction rate μ is equal to or more than the correction lower limit L2, the routine returns. .

In S11, the engine torque correction value μ is set to the correction lower limit L2. Here, the limitation of the engine torque correction value μ by the correction lower limit L2 will be described in detail. Contrary to high altitudes, when the temperature decreases, such as in a cold region or in winter, the air density increases, so that the engine torque increases even under a certain throttle opening. Then, the basic engine torque command value tT at this time
The correction of e acts on the side that suppresses the torque output, the engine torque correction rate μ decreases, and the Stroll valve 3 is closed.

Such correction on the output suppression side is preferable for stabilizing the torque output characteristic, but from the viewpoint of power performance, it cannot be used to the maximum. . Therefore, in a vehicle that emphasizes the power performance, by setting the correction lower limit L2 to 1, the correction on the output suppression side does not function, and the power performance of the engine 1 can be used to the maximum.

On the other hand, when the air density increases, excessive fuel tends to be injected even at a certain throttle opening, and the fuel efficiency deteriorates (normally, the accelerator is not depressed because the accelerator is not depressed). Not, but transiently worse.) Therefore, in a vehicle that emphasizes fuel efficiency, by setting the correction lower limit value to a value less than 1, when the air density increases, the correction of the basic engine torque command value tTe works to the output suppression side. Fuel economy can be prevented from deteriorating.

Next, a second embodiment of the present invention will be described. The hardware configuration of the engine control device according to the present embodiment may be the same as that of the first embodiment. Therefore, only the differences in the software configuration will be described here. The software configuration of the engine control device according to the present embodiment differs from that of the first embodiment in part of the engine torque correction rate calculation routine. In the present embodiment, the configuration of the engine torque correction rate calculation routine is simplified as compared with the first embodiment. Therefore, these differences will be described with reference to the flowchart shown in FIG.

FIG. 9 is a flowchart of an engine torque correction rate calculation routine according to the present embodiment. Steps indicating the same processing contents as those of the engine torque correction rate calculation routine according to the first embodiment are denoted by the same reference numerals. I have.
In this routine, the engine torque change rate dT is 1 in S2.
If it is determined that the engine torque correction rate is lower than 00-α (%), the process proceeds to S21, and the update range β
(Constant), and updates the engine torque correction rate μ. The update width β is such that the engine torque correction rate μ is 1 (100
%: No correction) to a value that takes about 5 minutes to reach 1.2 (120%).

When it is determined in S5 that the engine torque change rate dT is higher than 100 + α (%), the process proceeds to S22, in which the update width β is subtracted from the previous value μn−1 of the engine torque correction rate, and the engine torque correction rate is reduced. Update the rate μ. According to the present embodiment, the configuration of the engine torque correction rate calculation routine is simplified as described above. However, since the air density does not change suddenly while the vehicle is running, it is sufficient for the change in the air density. Can respond at speed.

In the above description, the basic engine torque command value tTe was determined using the first map m1. The present invention is not limited to this. For example, any target engine torque calculating method such as setting a target driving force and calculating a target engine torque from the target driving force and the gear ratio can be adopted. As an example, by applying the present invention to an automatic transmission that performs hydraulic control based on the accelerator opening, even at high altitudes and hot lands, the same performance as under standard conditions can be exhibited, and deterioration of shift shock can be reduced. Can be prevented.

In the above description, the first map m1
The throttle opening command value dTVO was determined from the corrected engine torque command value aTe using The present invention is not limited to this, and any method of calculating the throttle opening command value, such as first calculating the target opening area and then obtaining the target throttle opening, can be adopted.

[Brief description of the drawings]

FIG. 1 is a hardware configuration diagram of an engine control device according to a first embodiment of the present invention.

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

FIG. 3 is a diagram showing a relationship between engine speed, throttle opening, and engine torque under standard conditions.

FIG. 4 is a diagram showing a relationship between engine speed, intake air amount, and engine torque under standard conditions.

FIG. 5 is a flowchart of an example of an engine torque correction rate calculation routine.

FIG. 6 is a diagram showing a concept of forming a torque dead zone.

FIG. 7 is a diagram showing a change in engine torque according to a throttle opening;

FIG. 8 is a diagram illustrating an effect obtained by setting a correction upper limit value.

FIG. 9 is a flowchart of another example of an engine torque correction rate calculation routine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Intake passage 3 ... Electronic control type throttle valve 21 ... Electronic control unit 23 ... Backup memory 31 ... Hot wire type air flow meter 32 ... Accelerator opening sensor 33 ... Throttle opening sensor 34 ... Engine speed sensor 35 ... Water temperature Sensor 41: ignition switch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 9/02 351 F02D 9/02 351M 11/10 11/10 F 41/04 310 41/04 310C F term (Reference) 3G065 CA13 CA23 CA40 DA04 EA06 FA05 FA08 FA13 GA05 GA09 GA10 GA41 GA46 KA36 3G084 BA05 CA07 DA11 DA13 DA26 EA01 EA11 EB00 EB02 EB06 EB08 FA08 FA10 FA20 FA33 3G301 JA04 JA20 JB07 KA28 LA03 LC03 NC04 NE03 NA03 NC03 PA11Z PE01Z PE08Z PF03Z

Claims (14)

[Claims] 1. A mass weighing type air flow sensor, an engine torque estimated value calculating means for calculating an engine torque estimated value based on an intake air amount detected by the air flow sensor, and an engine calculated by the engine torque estimated value calculating means A control device for an engine, comprising: control parameter correction means for correcting a control parameter of the engine or its related devices based on an amount of deviation between a torque estimated value and a target engine torque based on operating conditions. 2. An electronically controlled throttle valve; an engine torque command value calculating means for calculating an engine torque command value based on a driver's intention; and an engine torque command value calculated by the engine torque command value calculating means. A throttle opening command value calculating means for calculating a throttle opening command value by using a mass weighing type air flow sensor and an engine based on an intake air amount detected by the air flow sensor. An engine torque estimated value calculating means for calculating a torque estimated value; a throttle for adjusting the throttle opening command value based on the engine torque estimated value calculated by the engine torque estimated value calculating means and the engine torque command value. An engine control device comprising: an opening command value adjusting means; 3. The throttle opening command value adjusting means calculates a divergence amount between the estimated engine torque value and the engine torque command value, and corrects the engine torque command value based on the divergence amount. The engine control device according to claim 2, wherein the throttle opening command value is adjusted. 4. The throttle opening command value adjusting means obtains a ratio between the engine torque estimated value and the engine torque command value as the deviation amount, and multiplies a correction rate based on the ratio by the engine torque command value. The engine control device according to claim 3, wherein: 5. The engine control device according to claim 4, wherein a correction rate of the engine torque command value is limited to a predetermined upper limit value or less. 6. The engine control device according to claim 5, wherein the upper limit value is equal to or less than a ratio of an engine torque when the throttle is fully open to an engine torque when the throttle is half open. . 7. The engine control device according to claim 4, wherein the correction rate of the engine torque is limited to one or more. 8. The throttle opening command value adjusting means calculates the throttle opening command value based on a first map in which an engine torque is allocated according to an engine speed and a throttle opening. The torque estimation value calculating means allocates the engine torque according to the engine speed and the intake air amount under the same pressure and the same temperature as the first map.
The control device for an engine according to any one of claims 3 to 7, wherein the estimated engine torque value is calculated based on the map (1). 9. The engine control apparatus according to claim 3, wherein the throttle opening command value adjusting means corrects the engine torque command value including an integral operation based on the deviation amount. Engine control device. 10. The throttle opening command value adjusting means, wherein the rate of change of the correction value of the engine torque command value is
The engine control device according to any one of claims 3 to 9, wherein the control is limited to a predetermined range. 11. The throttle opening command value adjusting means, wherein the rate of change of the correction value of the engine torque command value is
10. A method according to claim 3, wherein the constant is a constant.
The control device for an engine according to any one of the above. 12. The throttle opening command value adjusting means further comprises: throttle opening detecting means for detecting a throttle opening degree; and cooling water temperature detecting means for detecting a cooling water temperature of an engine. When the throttle opening detected by the throttle opening detecting means is smaller than a predetermined opening or the cooling water temperature detected by the cooling water temperature detecting means is lower than a predetermined temperature, the correction value of the engine torque command value is corrected. The control device for an engine according to any one of claims 3 to 11, wherein the rate of change of the engine is 0. 13. The throttle opening command value adjusting means,
Delaying the engine torque command value calculated by the engine torque command value calculation means, and adjusting the throttle opening adjustment value based on the calculated value and the engine torque estimated value. Claim 2
The control device for an engine according to any one of claims 12 to 12. 14. The throttle opening command value adjusting means,
14. The engine control device according to claim 2, further comprising a backup memory that retains stored information even after an ignition switch is turned off.