JPH01113541A - Engine control device - Google Patents

Abstract

PURPOSE:To prevent excessive output of an engine by compensating the value of a drive amount signal for an engine output regulating member, which is computed in accordance with an accelerator manipulation degree, in accordance with an operating condition of the engine, and by limiting thus compensated value in accordance with a limiting value which varies depending upon the accelerator manipulation degree. CONSTITUTION:In an engine control device in which an output regulating member A for regulating the output power of an engine, such as a throttle valve or the like, is electronically controlled for drive, there is provided a drive amount signal compensating means B for computing a drive amount signal for the regulating member A in accordance with an accelerator manipulation degree, and for compensating the value of the drive amount signal in accordance with an operating condition of an engine. Further, there is provided a limiting means C for limiting thus compensated value of the drive amount signal in accordance with a limiting value which varies depending upon the accelerator manipulation degree. This limiting value including an upper and lower limit values, and has such a characteristic that it gradually increases in accordance with increase in the accelerator manipulation degree. With this arrangement, it is possible to restrain excessive control of the regulating member due to overlapping of various kinds of compensations, thereby it is possible to prevent excessive engine power beyond anticipation by the driver.

Description

Detailed Description of the Invention (Industrial Application Unclear) The present invention relates to an engine control device that controls an engine by electronically controlling an engine output adjustment member such as a throttle, and particularly relates to an engine control device that controls an engine by electronically controlling an engine output adjustment member such as a throttle. The present invention relates to an engine control device that limits a control amount in appropriate response to an accelerator operation amount.

(Prior Art) Elements that adjust the output of an automobile engine include fuel supply amount, air-fuel ratio, etc., and the dominant factor that determines these adjustment elements is, for example, the opening degree of a throttle valve in a gasoline engine. In traditional gasoline engines,
This throttle valve is mechanically engaged with the accelerator pedal, so the throttle opening degree is determined by the amount of depression of the accelerator pedal.

However, when adjusting the throttle opening by mechanical engagement, the amount of accelerator depression and the throttle opening always correspond one-to-one, making it impossible to adjust the engine output in response to changes in driving conditions.

Therefore, along with the advancement of electronics, electronically controlled throttle controllers appeared, which consider the accelerator as an input source of driving request information from the driver, and allow the vehicle to judge the driver's driving request from the amount of accelerator depression.
The objective is to determine the optimal throttle opening degree by taking into consideration this request and the output characteristics of the engine. As a conventional example of such an electronic throttle controller,
For example, Japanese Patent Application Laid-Open No. 59-122742 is a technique related to improving the reliability of a throttle controller, and Japanese Patent Laid-Open No. 61-171846 is a technique related to improving the characteristics of throttle opening relative to the amount of accelerator depression.

Furthermore, there are some systems, such as the one disclosed in Japanese Utility Model Application No. 60-185039, in which, depending on the steering angle, the larger the steering angle, the more the throttle is tightened.

(Problem to be Solved by the Invention) Conventionally, the basic throttle opening is calculated from the accelerator operation amount, and then acceleration correction, steering angle correction, etc. are applied to this basic throttle opening. Generally, the final throttle opening is determined by adding various corrections.

However, each of the above-mentioned correction values is set individually, so when looking at a single correction, a value close to the required value can be obtained, but when multiple various corrections are applied at the same time, the overall value is The correction may be too large or too small, resulting in a value that is too inappropriate for the driver's accelerator operation. For example, if multiple corrections such as acceleration correction, temperature correction, and atmospheric pressure correction are performed with the accelerator depressed 30%, the throttle opening will be 100%.
%, and as a result, unexpected engine output may occur that does not match the driver's driving sensation.

Conventionally, so-called limiter processing has been performed to prevent the throttle opening from exceeding 100% or below 0%, but this only applies when the throttle valve is opened between 0 and 100%. This was done out of necessity due to its mechanical properties, which made it impossible to open and close. Therefore, the above-mentioned 30% does not work as a limiter for any example of accelerator operation in such a conventional device, and in the end, the throttle opens more than expected in response to the driver's accelerator operation, resulting in poor operability and driving performance. I felt bad.

That is, in the above-mentioned conventional technology, limiter control is taken into consideration only from the viewpoint of the mechanical characteristics of the throttle valve, and the result of electronic throttle opening control is excessive and independent of the driver's intention. There is basically a lack of perspective on how to prevent this.

Therefore, the present invention has been proposed in order to eliminate the drawbacks of the above-mentioned conventional examples, and its purpose is to limit the control of engine output adjustment members such as the throttle in response to accelerator operation in accordance with the amount of accelerator operation. Accordingly, the present invention proposes an engine control device that improves drivability by preventing excessive control of the adjustment member.

(Means and operations for solving the problem) As shown in FIG. means for determining the drive amount signal of the adjustment member based on the accelerator operation amount and correcting the value of the drive amount signal according to the driving condition; , and means for limiting by a limit value that changes depending on the amount of accelerator operation.

(Example) Hereinafter, an example in which the present invention is applied to a gasoline engine equipped with a turbocharger and an EAT function (electronic automatic transmission function) will be described in detail with reference to the accompanying drawings. This EA
As will be described later, the T function has gear positions (GP) from 1st to 4th (overdrive), and the shift modes include ``Power'' mode and ``Normal'' in the so-called 'DJ (drive) range. There are three modes: mode and economy mode, and each mode has its own unique shift pattern electronically prepared. These modes can be selected by the driver using a switch in the vehicle according to the driver's preference, as will be described later. In each of these modes, the speed at which the gears are shifted (shift point) is
In the above patterns, move to the lower side. That is, 1
If we look at the engine speeds, we can say that the gear ratios become relatively smaller in that order.

<Summary of the embodiment> Figures 2A and 2B show an overview of the throttle control in this embodiment, and in particular, Figure 2A shows it in steady state, and Figure 2B shows it in transient time. Indicated. Here, the steady-state characteristic refers to a static characteristic after a transient change in throttle opening with respect to a change in accelerator depression amount has elapsed.

According to FIG. 2A during steady state, the target throttle opening degree TAGET during steady running is first determined from a map according to the accelerator depression amount α (%). At this time, four types of maps are prepared as shown in FIG. 2A, depending on the accelerator mode and whether or not the accelerator is being released. In this way, the basic throttle opening TVOi+ is determined. This T
Corrections GAv and Gv are made for VOB based on accelerator depression speed &, vehicle speed V, supercharger boost pressure B, etc., respectively.

G6 is applied and the target throttle opening TAGE during steady state
Determine T.

According to Fig. 2A, the basic throttle opening characteristic TVO3 is as follows: Economy ((a) in Fig. 2A) - Normal ((b) in Fig. 2A) => Power (((b) in Fig. 2A)
In the order of C)), a wider throttle opening can be obtained with a slight change in the amount of accelerator depression. However, as it is, even within the same mode, the larger the gear ratio (3rd gear, 1st of 2nd gear), the greater the shaft output, which makes torque shock more likely to occur. The larger the value, the lower the throttle gain is set.

Furthermore, when the accelerator is released, regardless of the mode setting, the characteristic as shown in (d"I in FIG. When the accelerator is pressed down and the accelerator is released, deceleration is performed as requested by the driver.

Furthermore, according to (e) in FIG. 2A, in the power mode, the higher the accelerator depression speed &, the higher the gain GAV is intended to respond to the driver's acceleration request. This is because, regardless of the magnitude of the accelerator depression amount α, a large depression speed α indicates that the driver is requesting acceleration.

According to (f) in FIG. 2A, the higher the vehicle speed is, the higher the gain Gv is.

According to (g) in FIG. 2A, the higher the boost pressure, the smaller the gain Ga. If the boost pressure is high, the engine torque will be large, resulting in a so-called turbo-like peaky output characteristic with steps, but by adding the correction shown in (g), a flat output characteristic can be obtained and the vehicle's Controllability of exercise can be improved.

Thus, the target opening degree TAGET according to the steady-state characteristic is TAGET = T V 0a-GAv 'Gv-
It is Ga.

Note that the correction factors for the target throttle opening TAGET in the steady-state characteristics applied to this embodiment include water temperature correction, atmospheric pressure correction, steering wheel steering angle correction, and correction when the air conditioner is operating. Since it is not directly related to the invention, its explanation will be omitted.

During a transient period FIG. 2B shows throttle control during a transient period when the accelerator opening changes. That is, the final target throttle opening degree TAGETF is determined by correcting the target opening degree TAGET calculated and determined under steady state conditions.

That is, variable limiter processing as shown in FIG. 2B (a) is applied to TAGET. The product GAV 'GV''GB of each correction gain of the embodiment shown in (e) to (g) of FIG. 2A is:
In some cases, the value may be quite large, such as 1 or more, giving a throttle opening that the driver cannot predict from the accelerator operation. In order to prevent this excessive throttle opening, it is necessary to perform variable limiter processing as shown in (a). As shown in the figure, this limiter value has an upper limit value and a lower limit value that are variable depending on the accelerator depression amount α. These upper and lower limit values are 0 when the accelerator depression amount α is 0, and 100 when the accelerator depression amount α is 100. It can be prevented.

(b) to (d) in FIG. 2B perform filter processing. In this embodiment, a digital first-order response filter is used.

With this -order response filter, the rapid increase in TAGET corresponding to the rapid increase in accelerator opening is smoothed and becomes gentle. Furthermore, the coefficient β (reciprocal of the time constant) of this filter is changed when using 1st gear, when releasing the accelerator, or when using mechanical control when the electronic control of the throttle described below fails (see Fig. 2B). (b)) is set to β±1, and when the accelerator depression speed is large, the coefficient β is set relatively small ((c) in Figure 2B), and when & is small, the coefficient β is set to a relatively small value. ((d) in Figure 2B).

According to FIG. 2B (b), there is no response delay and the vehicle responds sensitively to changes in the accelerator, so the requirement that starting responsiveness is emphasized when using the first gear is satisfied. Even when the accelerator is being released, there is no response delay and it responds sensitively, so it accurately follows the driver's intention to decelerate. Also,
When the accelerator depression speed & is large, that is, during sudden acceleration, the response delay becomes large, torque shock is reduced, and smooth acceleration is achieved.

Note that the transient characteristic control of the throttle opening shown in FIG. 2B changes depending on factors such as the first gear, the accelerator depression speed & whether the accelerator is being released or not, but in this specification, it is shown in FIG. 10C etc. Furthermore, embodiments in which gear positions, setting modes, etc. are also taken into account are also disclosed.

<Configuration of Engine Control System> FIG. 3 is a configuration diagram of an embodiment in which the engine control device according to the present invention is applied to a turbocharged engine. To explain the main components in the figure, 1 is an air cleaner, 2 is an intake temperature sensor, 3 is an air flow meter, 4 is a turbocharger, 5 is a waste gate valve, 6 is an engine body, and 7 is an intercooler. In this way, the air taken in according to the supercharging of the turbocharger 4 moves toward the intake manifold of the engine body while being cooled by the intercooler while having its intake air amount Q1 measured by the air flow meter 3.

8 is a throttle valve, 9 is an actuator that drives the throttle valve, 10 is a boost pressure sensor that measures the pressure in the intake pipe, and 11 is an injector. Thus,
The intake air is mixed with fuel injected from an injector 11 while its amount is regulated by a throttle valve 8, and is supplied to a combustion chamber in the engine body 6, where it is combusted and exploded. The exhaust gas passes through the exhaust passage, converts its combustion energy into rotational energy and gives it to the turbocharger 4, and is further purified by the catalytic converter 12 and exhausted.

13 is an electronically controlled automatic transmission, so-called EAT. This EAT 13 is controlled by an EAT controller (EATC) 50. As is well known, the inside thereof includes a torque converter 14, a planetary gear section 15 equipped with an overdrive mechanism, and a hydraulic control section 17 containing solenoid valves, hydraulic circuits, etc. for these components. EATC5
Between 0 and EAT13, in addition to the signal that opens and closes the solenoid valve to drive the hydraulic circuit, there are shift signals (5QLI to 5QLI to be described later) that indicate the shift result state based on this signal.
There are signals such as OL4). Further, a vehicle speed sensor 16 is provided on the output shaft of the EAT.

18 is a throttle controller incorporating a servo control circuit for a DC servo motor that drives the throttle valve. Note that this servo motor is located within the throttle actuator 9. 20 is an accelerator pedal, and 21 is an accelerator position sensor that detects the amount of depression of the accelerator.

Related switches〉 FIG. 4A shows the above-mentioned modes (power, normal).

This is a switch to select economy (economy).

Figure 4B shows the switches for making full use of the so-called automatic driving function. (SET)" switch is for setting the chain speed and for accelerating by holding down this switch for a predetermined period of time.
RESUME J is a switch to return to the original chain speed after automatic driving mode is canceled.
The COAST J switch is for fully closing the throttle.

<Throttle Sensor/Actuator> FIG. 5 shows the configuration of the throttle sensor/actuator assembly used in the engine system of this embodiment. This sensor/actuator has a so-called fail-safe function in view of the important role of the throttle valve in automobiles.

In FIG. 5, 8 is a throttle valve, 9 is a throttle actuator, 18 is a throttle controller, and 20 is an accelerator pedal. These have already been explained in connection with FIG. There are two accelerator position sensors 21 for fail-safe purposes that detect the amount of accelerator depression.
1b is the main one, and 21a is for backup. These sensors are potentiometers, and their output is a percentage of the amount of accelerator depression when the accelerator is fully depressed, which is converted into a voltage value. 29 is a pulley linked to the accelerator pedal 20 by a wire;
31 is an engagement piece linked to the throttle valve 8.

The throttle actuator 9 includes a servo motor 28 and
The solenoid 27, the pulley 25, the electromagnetic clutch 25 that transmits the rotational force of the DC servo motor 28 to the pulley 25 when the solenoid is energized, and the rotation amount and rotation speed of the pulley 25 for servo control of the motor 28. It consists of a rotation sensor 24 and the like for detecting and feeding back to the throttle controller 18. Pulley 25 is linked to pulley 32 by a wire. Although the pulleys 29, 32 and the engagement piece 31 rotate about the same rotation axis, in FIG. 5, for convenience of explanation, the rotational motion is converted into linear motion. . The throttle sensor 33 is
Detecting the fully open or fully closed state of the throttle valve 8;
Throttle valve 8 when the electronic throttle control malfunctions.
This is to detect the throttle opening when the pulley 29 directly drives the throttle opening.

The pulley 29 and the engagement piece 31 have some play up to their engagement position, and the engagement piece 31 is normally set to be engaged with the pulley 32.

Further, when the ECU 40 determines that the self-diagnosis is OK, the clutch 26 is in a connected state. Therefore,
When the accelerator 20 is depressed, the accelerator depression amount α is detected by the sensor 21a, and at the same time, the signal α is sent to the ECU 40 via the throttle controller 18. Then, in the ECU 40, the final target throttle opening degree TAGETF is immediately calculated by the control described below, and the result is sent to the throttle controller 18.

The throttle controller 18 D/A TAGETF.
The sensor 24 is converted to rotate the motor 28 and the sensor 24
Based on the feedback signal from the rotor, servo control is performed to maintain a predetermined rotational position. That is, since the servo motor rotates by an amount corresponding to TAGETF to rotate the pulley 32, the engagement piece 31 rotates due to the engagement, and the throttle valve 8 is opened by an amount corresponding to TAGETF.

When the engaging piece 31 rotates, the engaging piece 31 escapes from the pulley 29, so that the throttle valve 8 is not directly opened or closed by the pulley 29 under normal conditions.

On the other hand, when it is determined that the control circuit related to throttle control is abnormal, the electromagnetic clutch 26 is disconnected, so the pulley 2
9 and the engagement piece 31 are engaged, and thereafter the throttle valve 8 is directly opened and closed by mechanical connection with the accelerator pedal.

(Input/Output Signals to Controller 40) FIG. 6 is a diagram showing input/output signals, etc. of the ECU 40.

α (mask) and α (sub) are the amount of accelerator depression from the aforementioned throttle actuator.

Similarly, the throttle opening degree is also measured by the throttle sensor 33 for the throttle and the throttle (sub).

Shift solenoid signal (SQLI~5OL4) is EATC
This signal comes from 50 and indicates that the current shift position is one of the 1st to 4th gears. P
, N, and R range signals are signals indicating select positions from a well-known selector lever. Also, normal, power,
The mode signal such as economy is a signal from the switch shown in FIG. 4A. MAIN, SET, RES, C0
Signals such as AST are signals from the switches shown in FIG. 4B.

The engine speed N is obtained from the distributor 41, the vehicle speed signal V is obtained from the vehicle speed sensor 16, the water temperature Tw signal is obtained from the water temperature sensor 42, the atmospheric pressure signal PA is obtained from an air pressure sensor (not shown), the boost pressure B is obtained from the boost sensor 10, and the steering angle is The signal is a signal obtained from a steering angle sensor (not shown), and the A/C load signal is a signal obtained from an air conditioner (not shown).

In addition to the above-mentioned TAGETF, output signals include a signal for forcibly turning off the power to the DC servo motor 28, a signal for turning off the clutch 26, and the like.

Further, as another fail-safe mechanism, two systems of brake switches are provided. Furthermore, when the brake pedal is pressed, the accelerator is fully closed, so the circuit shown in FIG. 6 turns off the power to the servo motor 28.

That is, the throttle is forcibly fully closed without any calculation control by the ECU 40.

In the ECU 40 of FIG. 6, among the control functions performed within the ECU 40, portions particularly relevant to the present invention are shown in block form. Its functions include driving feel control, throttle target value control, and throttle calculation control. Driving feel control attempts to set an optimal throttle-to-throttle value based on the amount of accelerator depression, gear position, driving mode, etc.

Other features include automatic cruise control (ASC) and failsafe.

In Fig. 6, the throttle target value setting control selects either the driving feel control or the ASC control input, but this is because the driving feeling control is mainly based on the driver's accelerator depression. In contrast, during automatic driving, the throttle opening is determined based on the set vehicle speed and the actual vehicle speed, regardless of the driver's accelerator operation. This is because it is for a good reason.

Configuration of Controller> FIG. 7 is a block diagram showing the internal configuration of the ECU 40 that performs throttle control. 301 is an input/output (Ilo) boat, and 302 is a CPU such as a microprocessor.

The output port part of 301 is a latch type,
Connected to driver 308. Further, 303 is a ROM for storing control programs, maps, etc. related to the embodiments described later;
304 is a RAM for storing various temporary data used for control, 305 is a programmable timer that sets the time for timer interrupt, and 306 is A for converting accelerator depression amount α etc. into digital values. /D converter (ADC). 307 is an interrupt control unit.

<Outline of Throttle Control> FIG. 8 shows the relationship between control programs in the engine control system shown in FIG. 3, focusing on parts particularly related to this embodiment. Of the control programs shown in Figure 8,
In this specification, details of parts related to EAT control and parts related to fuel control are omitted because they are not particularly relevant to the present invention.

Parts of the control program that are particularly relevant to the present invention are the throttle control main routine shown in FIG. 8 (the details of which are shown in FIG. 9 and below) and the throttle opening output routine (the details of which are shown in FIG. 10 and below). . The former is activated by a timer interrupt every 30m5, and the latter is activated by a timer interrupt every 15ms. Note that these times are merely examples, and the main routine control interval of 30 m5, for example, may be determined by setting a control period that is several times or more the highest frequency to be controlled for the controlled object. Further, the subroutines called by these two interrupt routines are further shown in FIG.

An outline of the main routine of throttle control will be explained with reference to FIG. As mentioned above, this main routine is
A timer is started every 30m5.

First, in step S2, an accelerator operation by the driver is detected. Details of this subroutine are shown in FIG. 9A.

Step S4. In step S6, the accelerator opening α and mode M detected by the timer interrupt routine every 10 m5 (Fig. 10), which will be described later, are read from the memory, and based on these signals, in step S8, the basic throttle opening map (ROM 303) is read out. ) to determine the TVOB. The TVOB search in step S2 corresponds to (a') to (d) in FIG. 2A, and its details are shown in FIG. 9C.

For the TVOB obtained in step S2, step S
At step 10, the accelerator depression speed is corrected to obtain an output Tc. This step SIO correction process is shown in FIG. 2A (e).
The details are shown in FIG. 9D.

Next, in step Sit, it is checked whether the current driving mode is in the power mode (M=3), and only when the current driving mode is in the power mode, in step S14, correction is made according to the vehicle speed, and the throttle opening T1 is adjusted. get. - This vehicle speed correction corresponds to (f) in FIG. 2A, and its details are shown in FIG. 9E.

In step S16, boost pressure correction is performed.

This correction corresponds to (g) in Figure 2A, and its details are shown in Figure 9.
Shown in Figure F. Next, in step 518, variable limiter processing is performed. This limiter processing corresponds to (a) in FIG. 2B, and its details are shown in FIG. 9G.

In this way, in a certain mode and gear position, the steady state (quiet) throttle opening TAGET for the accelerator opening α based on a certain depression position was calculated.

An outline of the throttle opening output routine will be explained with reference to FIG. This routine is started by a timer every 15 ms, and a part of this output routine includes control (filter processing) for the initial period (transitional period) when the accelerator opening degree α is changed. In step 3200, the vehicle speed V is input from the vehicle speed sensor 16, and in step 5202, the accelerator opening degree α and the boost pressure B are manually input from the A/D converter 306. Furthermore, for later calculations, the previously measured and stored accelerator opening value (for example, 15 ms ago) is stored in αn-1, and the currently measured α is set to α. Store in. In addition, in step 5204, the speed change gear position GP and mode switch position are stored in the RAM 30 from the human-powered boat 301.
Load within 4.

Here, GP=1 (1st speed) GP=2 (2nd speed) GP=3 (3rd speed) GP=4 (4th speed) M≠3 (Power mode) M=2 (Normal mode) M=1 (Economy) mode). The data stored in these RAMs 304 is used in various steps in other controls. In step 5206, accelerator depression speed & is calculated. The details of this calculation routine are shown in FIG. 10A.

This a is used in the vehicle speed correction subroutine described above. Here, for convenience of explanation, the accelerator depression speed calculation routine will be explained first.

Step on the accelerator In step 5210, the previous accelerator opening degree α.

and the previous accelerator opening degree αn-1 are read from the RAM, and in step 5212, the accelerator depression speed is calculated as follows: and=αn-αn-1. That is, in this example, 15 m
The change in opening between s and s is defined as the accelerator depression speed. In addition, in order to accurately understand the driver's intention, for example, 60m5
It may also be compared with previous data, ie, αn+4. That is, 5E禦α. -αn-4, and this time interval is preferably as short as possible so that the driver's intention can be reliably grasped and the intention can be fed back to the control as quickly as possible.

In step 5214, □ is compared with itself, where ex, , is the maximum value of that was detected in the past in one accelerator operation process of continuing to depress the accelerator at a certain speed. & is increasing, i.e., h > ex am −X, then in step 5216 this current and
Update x,,X. That is, and □←& . Next, in step 5218, & is compared with a predetermined small constant ε. If to is smaller than ε, that is, especially ε, this means that the accelerator is stopped being depressed (the accelerator has almost stopped).
state, then in step 5220, et,
, , let x be “0”. By doing this, ′
When the value is not 0'', □8 is the maximum accelerator depression speed when the accelerator is continuously depressed (α increases to AAA).

Since the values obtained in this accelerator depression speed calculation subroutine and ex, , and X are used in other routines,
It is stored in RAM 304.

Returning to the explanation of FIG. 10 again. Step 3208 performs response processing for the transition period of accelerator changes, calculates the final target throttle opening TAGETF, and outputs it to the throttle actuator 9, as shown in (b) in FIG. 2B.
) to (d), the details of which are shown in FIG. 10B.

Note that FIG. 10B shows one form of transient response processing,
A modified embodiment thereof is shown in FIG. 10C.

[Margin below] Details of throttle opening control will be described below based on a flowchart.

<Details of throttle steady-state control> L (Fig. 9A) In step S20, the accelerator depression speed & is stored in the RAM 30.
4, and in step S22, the flag AF is checked. This AF flag is reset to "O" in the initial state, and is set to "1" when an accelerator release operation is detected. The detection of this accelerator return operation is done in order to change the basic throttle opening map at the time of return, and to detect the TAGE
Necessary in the TF transient processing (steps S44 and 34B in FIG. 9C and step 52□48 in FIG. 10B)
).

Now, assume that the accelerator opening degree α is changed by the driver as shown in FIG. 9B. At the initial stage, the AF is reset, so the process advances to step S24. When it is detected in step S24 that the accelerator is being depressed, that is, when and >0, it is determined that the accelerator is being depressed, and step S3
Leave the AF reset in step 2. That is, while the accelerator is being depressed, steps 520=>step 522=>step S32 during step 324 are repeated.

When the accelerator opening degree α decreases as the accelerator is about to start returning, it is detected that and ≦0, and the process proceeds to step 326. In step 326, it is determined whether the accelerator returning operation has reached a speed above a certain level, that is, & Determine <-A (A' is a positive number). - If it is not larger than the window, it is treated as noise (step 328).

When α<-A is detected, the process advances to step S30, and the AF is set to "
Set to 1”.

- Once the AF is set, the process proceeds from step S22 to step S34. In step S34, it is determined whether the accelerator depression speed & exceeds a constant value A. If the AF is exceeded, the AF is reset in step S36, and as long as the AF does not exceed A while returning or pressing down,
AF remains set (step 530).

In this way, the released state of the accelerator is detected. Furthermore, false detection can be prevented by providing a dead area from -A to A. This is because in this embodiment, when the accelerator is released, the throttle is closed along a different curve from when the accelerator is depressed (see Figure 12B), so the false detection of the accelerator release is caused by a sudden change in the throttle opening. Because it connects.

Note that A in step S26 and A in step S34 may be different values.

Basic throttle map search (9c step S40
．． In S42, it is checked whether the current driving mode M read in step S6 (FIG. 9) is economy mode, normal mode, or power mode. Furthermore, it is checked whether the accelerator is being released (AF=1) in either normal mode or power mode (step S).
44,546). Then, a map suitable for each state is determined, and in step S56, the accelerator depression amount α at that time is determined.
The basic throttle opening degree TvO11 corresponding to the condition is read out from the map.More detailed characteristics of the map corresponding to each state are shown in FIGS. 11(a) to 11(d).

Here, the merits of having an accelerator return map will be explained by comparing FIGS. 12A and 12B. In the power mode or normal mode, as can be seen from FIG. 11, the slope is relatively steep below a certain accelerator opening, and conversely becomes relatively gentle above that opening. Such an accelerator opening degree is often at least medium speed or higher. On the other hand, it goes without saying that in such a speed range of medium speed or higher, when the driver releases the accelerator, the vehicle will naturally decelerate in response to the release, resulting in a more stable driving experience.

However, even when the accelerator is released in power mode and normal mode, the condition shown in FIG. 11(b) occurs.

If we use a characteristic map like (C), for example, in power mode, in Fig. 12A, the accelerator opening is Δα1.
If the throttle accelerator is returned by 1, the change in throttle accelerator opening will be ΔT, which is extremely small. Therefore, the deceleration caused by returning the accelerator will be smaller than expected by the driver. Conversely, when the accelerator opening is small (for example, 20%), a large change in the throttle opening occurs even with a slight change in the accelerator opening, and the deceleration becomes more than expected.

Therefore, if a relatively linear return characteristic as shown in (d) of Fig. 11 is added to the power mode and normal mode, as shown in Fig. 12B, the accelerator opening decreases (Δ
Throttle opening decrease (ΔTu) linearly corresponding to α2)
t) is obtained, and the above-mentioned disadvantages are solved.

The reason why the return characteristic is not added to the economy mode is that, as can be seen from FIG. 11(a), the characteristic is relatively linear and therefore unnecessary.

However, an engine with poor output characteristics in a low throttle opening range requires a map characteristic with a large gain. In such cases, even in economy mode,
A map is required for when the accelerator is released.

Accelerator depression correct (9th D First, in step S60, the maximum accelerator depression speed ex, , calculated in the accelerator depression speed calculation routine of step 5206 is read from the RAM 304.Step S6
2. In S64, the current operation mode is checked, and in step S6
In steps 6 to S70, a correction gain map corresponding to the current driving mode is selected. Then, in step S72, from the selected map, the correction gain G according to et, .
Read AV and calculate To = TVOB x et al.

Here, GAv is h for economy mode,
, , GAV=1. That is, in this embodiment, no correction is made. On the other hand, the tendency of the characteristics of GAv in normal mode and power mode is such that the larger the maximum accelerator depression speed h 1 lax, the higher the gain, in order to meet the driver's acceleration request. Regardless of whether the accelerator opening is low or high, a large depression speed &...X indicates that the driver is requesting acceleration.

In addition, in this embodiment, in economy mode, GAv
However, depending on the characteristics of the engine, for example, if the engine output is poor in a region where the throttle opening is low, GAV≧1 may be set.

Here, GAv is not the pressing speed at that point,
The reason why it is determined according to the maximum accelerator depression speed a□ is as follows. That is, when the driver attempts to increase acceleration, ex-wax is constantly updated, so the expressions &1.1.8 have the same meaning. On the other hand, when increasing or decreasing within the range of &≧ε, the emphasis is on the driver's intention to accelerate, rather than when decreasing.
, llX to obtain the correction gain GAV. Even if you do this, aIIx becomes “0” when &ε
At this time, GAV becomes "1", that is, there is no correction, so, and 1. If X exceeds &A (see steps S66 to S70), the value of GAv remains unchanged, so there is no problem.

Once the correction gain GAv is determined, the provisional target throttle opening T is determined in step S72. is calculated by To = TVOa XGAv.

"Correct""Figure 9E) In step 374, the vehicle speed V read from the vehicle speed sensor 16 in step 5200 (Figure 10) is stored in the RAM 30.
4, the correction gain GV corresponding to the vehicle speed is read out in step S76, and TI-TOXGv is calculated in step 878. In this example, the vehicle speed V is 60 Kn+/
This correction becomes effective when the speed exceeds 120 Km/h.
When the value exceeds , the correction gain is stopped.

Boost pressure Fig. 9F In step S80, the accelerator depression speed & obtained in step 5212 is taken out, and in step S82, step S2
Take out the boost pressure B obtained at 0'2. Then, the boost pressure correction am (step S86.588) is selected which has a characteristic of taking a relatively smaller value when the boost pressure B is positive than when the boost pressure B is negative. That is, G11 (B: positive) < G, (B: negative). In this way, when the boost pressure B is negative, the gain is increased to quickly bring the engine to the turbo zone (boost pressure is positive). Further, when the boost pressure is positive, by setting the gain low, it is possible to compensate for the difficulty in controlling the dynamic characteristics of the vehicle due to an excessive increase in engine output, and to prevent acceleration shock.

Generally, when sudden acceleration is performed, the vehicle speed increases and the boost pressure B changes from negative (indicated by 1) to positive (indicated by II).
It will change to. In the conventional case, as shown in Fig. 13A, an acceleration shock occurs at the time of transition from the region (■) to the region II, but according to the present embodiment, as shown in Fig. 13B, the acceleration shock occurs quickly. It can be seen that the acceleration reaches its maximum at , and after that the acceleration becomes smooth with little variation.

Now, in the embodiment shown in FIG. 9F, simply the boost pressure B
In addition to performing a correction that has a characteristic that takes a relatively smaller value when the value is positive than when it is negative, by performing more precise correction control, the driver's intention can be adjusted from the driver's accelerator operation. The system reads more information and performs throttle control that corresponds to the accelerator operation. That is, as shown in step 386, & is the predetermined value α
5 or more, that is, when the driver is trying to accelerate rapidly, and the driver is not in the turbo zone, the smaller the boost pressure B, the faster the value of GB is set to be thicker than "1". Once in the turbo zone, boost pressure correction should not be performed (GB = 1).

The fact that the accelerator depression speed & is &ku6 means that the driver does not want sudden acceleration, so in the non-turbo zone, a certain degree of acceleration is maintained, and in the turbo zone, it is necessary. In order to suppress the above acceleration, GB is set to 1 or less.

Limiter Processing (Figure 9G) In this process, when T2 calculated by the various corrections explained above becomes excessive or insufficient, it is processed by a variable limiter according to the accelerator depression amount α, so that the driver can This prevents the throttle opening from becoming unpredictable based on the amount of accelerator pedal operation, and prevents the driver from feeling uncomfortable with the control system.

Therefore, first in step S91, the current accelerator opening degree α
Upper limit value TUP + lower limit value according to. Read 0. Then, it is checked whether the calculated throttle opening degree T2 is larger than TLIP (step 592) or smaller than T low (step 594), and if it is larger than Tup, T2 is limited to T"up. Step 896)
, TLow, T2 is limited to TLow (step 598). And then T in step 5too.

TAGET is the steady state throttle opening.

In this way, by making the limiter values TIJP and TLow variable according to the accelerator depression amount α, the throttle opening TAG, which is unexpected from the current accelerator opening α, can be adjusted.
Prevents becoming an ET. Then, step S91
As shown in the figure, by setting the upper limit Tup for the maximum accelerator opening α to 100% and setting the lower limit TLOw for the minimum accelerator opening α to 0%, the throttle opening can be varied from 0% to 100%. The throttle valve 8 can be opened and closed only within this range, and can also be controlled to match the mechanical characteristics of the throttle valve 8.

As described above, in a certain driving state, (CI) depending on the driving mode, (II) depending on the accelerator opening α, (III) depending on whether the accelerator is being released or not, (CI)
IV) Depending on the accelerator depression speed etI11□, (V)
Depending on the vehicle speed V, (V+) boost pressure B and accelerator depression speed &, (■) variable limiter processing is applied according to the accelerator opening α, and the static characteristic TAGET of the throttle opening is determined. Ru.

Details of throttle control during transient times〉...Basic example Throttle control during transient times mainly uses a temporary response filter to absorb sudden changes in throttle opening when the accelerator opening α changes significantly. It is for the purpose of Furthermore, by changing the coefficient (reciprocal of the time constant) of this response filter depending on the running conditions, an optimum running time can be obtained.

First, the digital filter will be explained. 1st
As shown in FIG. 4, in order to absorb the sudden change in the throttle opening shown by the broken line, it is appropriate to change the throttle opening as shown by the solid line. Such a curve can be obtained, for example, as an exponential function curve, and a -order response filter is suitable for realizing it as a filter. It is well known that the -order response filter corresponds to an RC integration circuit as shown in FIG. 15 when expressed as an electric circuit. In this integrating circuit, there is a relationship between input voltage X and output voltage Y. S is a differential operator. Then, converting the above equation into time space, it can be rewritten as , so we get . It is well known that RC is a time constant, and when this value is large (the reciprocal is small), the curve will be gentler, and when the time constant is small (the reciprocal is large), the curve will be steeper. . Therefore, in the following explanation, Xn of the above formula
Let be TAGET obtained by the limiter processing in step 3100, and let Yn be the final throttle opening target value TAGETF.

Now, the control will be explained according to FIG. 10B. Step 5
230. At step 5232, the depression speed & gear position GP is read. In step 5234, the step 51
The provisional target throttle opening degree TAGET calculated with 00 is stored in THRl in the RAM. Step 5236
Now, the final throttle opening TAGETF calculated last time (30 ms ago) is read from THR in the RAM.

At step 3238, it is determined whether the throttle is in the closing direction or in the opening direction. That is, if it is in the closing direction, T HRr <T HR2 , so the process advances to step 5252 and THR2 is updated. Then, in step 5254, T of THRI is
AGET is set as the final throttle opening TAGETF, and in step 5256 this TAGETF is output to the throttle actuator 9 via the throttle controller 18. This is because when it is in the closing direction, there is no need to perform the response delay fill 31 process.

On the other hand, when the throttle is in the opening direction, that is, THR, ≧THR.

If so, proceed to step 5240. Step 5240
This is to change the value of the coefficient β according to the value of . In other words, Tokuto.

In that case, since the acceleration shock is considered to be small because the accelerator depression speed is small, β should be set to a thick value (for example, β =0°08) (Step 5
242), on the other hand, when &≧&0, the coefficient β is set to a small value (for example, β-0,04) in order to make the throttle change more gradual in response to the accelerator change in order to suppress the acceleration shock. settings (step 5244).

At step 5246, filtering processing is performed. This means that the current THR is the previous THR2 (30ms ago).
This is a filtering process that gradually increases by βX (T HRr - T HR2). For example, β=
If it is 0.04, then Also,&. For example, a suitable value is 9.4% 7.5ms.

In step 3248, the gear position is in 1st gear (GP=
1) or if the accelerator is being released (AP=1). If the gear is in 1st speed or AF=1, the value calculated in step 8246 is not used as the value to be stored in THR2, but TAGET is used in step 5250. This is because when the vehicle is in first gear or when the accelerator is being released, emphasis is placed on the response speed to the accelerator operation. That is,
1st gear is often used mainly when starting, and at this time the engine speed is low. This is because the low rotational speed region of the engine is a low torque region (particularly noticeable in turbo engines), and in AT vehicles, this appears as a deterioration in the response of starting rather than an acceleration shock. Also,
This is because if filter processing is performed while the accelerator is being released, a feeling of deceleration that matches the feeling of the driver's accelerator operation cannot be obtained.

If -6Av=1 in 1st gear, and there is none, step 5
250. In step 5256, the delayed THR,
is output as the throttle opening.

Details of throttle control during transient times〉...Modification The basic system of throttle control during transient times described above is based on the gradualness of the change in throttle opening relative to the change in accelerator opening α, depending on the accelerator depression speed &. Although it changes the degree,
This modified example attempts to change the degree of gentleness of the change in throttle opening according to the gear position GP and driving mode M, and the details of this control are described in Section 10C.
As shown in the figure.

Now, in the basic form shown in Fig. 10B, two types of β are prepared depending on the value of the accelerator depression speed &, but in this modification, the value of β is determined according to &, the gear position GP, and the driving mode M. , it is sufficient to explain only how to select β. The selection step is step 5278, and the detailed program is
It is shown in Figure 00. Further, the correspondence relationship between the coefficient β selected by the control shown in FIG. 10D, the gear position GP, and the operation mode M is shown in FIGS. 10E (a) and (b).

According to the relationship shown in FIG. 10E, β is relatively small as ■: accelerator depression speed & increases. This is the first
This is due to the same reason as the control related to the basic form shown in the OC diagram.

(2): Except when in 1st gear or when the accelerator is being released, in low gear, β is made small to increase the delay time. This is because the torque is large in low gears, so the acceleration shock caused by changes in accelerator pedal speed is large.

■: The values of β regarding the modes are in the following order: β (power), β (binormal), β (economy). In other words, the delay is greater in normal mode than in economy mode, and greater in power mode than in normal mode.

In this way, by setting the primary response delay time according to the accelerator depression speed & gear position GP and driving mode M, sudden changes in accelerator opening are smoothed out without becoming sudden changes in throttle opening, and acceleration shocks are smoothed out. A reduction is planned.

(Other variations) In the embodiment described above, variable limiter processing is applied to the final throttle opening T2 after various correction processes, but of course, variable limiter processing is applied each time correction is performed. Good too.

In the embodiments described above, an EAT vehicle has been described, but the present invention can also be applied to a so-called MT vehicle.

This is because even in manual transmission cars, low gears have the problem of acceleration shock when the accelerator is pressed hard. In the above embodiment, the shift mode is also changed by changing the shift point, but the present invention can also be applied to automobiles in which the shift mode is changed by changing the final gear ratio.

Moreover, it is applicable not only to gasoline vehicles but also to diesel vehicles.

Furthermore, the supercharger is not limited to a turbocharger, but can also be applied to a so-called supercharger, an inertial supercharger, and the like.

(Effects of the Invention) As explained above, according to the engine control device of the present invention, the driving amount of the engine output adjusting member is first basically determined according to the accelerator operation amount, and then further corrected according to the driving state. is performed, for the corrected drive amount,
A restriction process is added so that this amount does not exceed a variable limit value depending on the amount of accelerator operation. Therefore, excessive control of the adjustment member due to duplication of various corrections is suppressed, thereby preventing excessive engine output beyond the driver's expectations and ensuring good drivability.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIGS. 2A and 2B are an overall diagram of throttle opening calculation control according to an embodiment, and FIG. 3 is an overall diagram of an engine system to which the present invention is applied. 4A and 4B are diagrams explaining the switches used in the automobile of the embodiment shown in FIG. 3, and FIG. 5 is a diagram explaining the relationship between the throttle actuator and the throttle controller. Figure 6 shows the engine controller unit (ECU) 40.
7 is a diagram showing the configuration inside the ECU 40, FIG. 8 is a diagram showing the relationship between engine control and automatic transmission control, FIG. 9 is a flowchart of the main routine of the throttle control program, Figure 9B is a flowchart of the accelerator operation detection control program, Figure 9B is a diagram showing a specific example of the relationship between accelerator operation and flag AF, Figure 9C is a flowchart of the basic throttle opening map search control program, and Figure 9D is accelerator depression speed. 9E is a flowchart of the vehicle speed correction control program. 9F is a flowchart of the boost pressure correction control program. 9G is a flowchart of the variable limiter processing control program. 10 is the throttle opening output routine. FIG. 10A is a flowchart of the accelerator depression speed calculation control program. FIG. 10B is a flowchart of the control program for response delay processing according to the basic form. FIGS. 10C and 10D are flowcharts for response delay processing according to the modified example. Flowchart of control program, FIG. 10E (a),
(b) is a table showing the characteristic values of the coefficient β according to the above modification, Figures 11 (a) to ('d) are characteristic diagrams of the basic throttle opening map, and Figures 12A and 12B are accelerator pedals. Figures 13A and 13B are diagrams explaining the necessity of the return map, Figures 13A and 13B are diagrams illustrating the effect of boost pressure correction according to this embodiment in comparison with a conventional example, and Figure 14 is a diagram illustrating the effect of the first-order response filter. Timing Chart FIG. 15 is a diagram illustrating a method for designing a primary response filter using a digital filter. In the figure, 1...Air cleaner, 2...Temperature sensor, 3...
Air flow meter, 4...turbocharger, 5-...
・Wastegate valve, 6...Engine body, 7.
...Intercooler, 8...Throttle valve, 9...
Throttle actuator, 10... Boost pressure sensor, 11... Injector, 12... Catalytic converter, 13... Electronically controlled automatic transmission, 14... Torque converter, 15... Planetary gear mechanism, 16 ... Vehicle speed sensor, 17... Hydraulic control unit, 18... Throttle controller, 20... Accelerator pedal, 21, 21
a, 21b...Accelerator opening sensor, 24.33...
・Throttle opening sensor, 25, 29. 32... Pulley, 26... Clutch, 27... Solenoid, 28
...DC servo motor, 31...engaging member, 40.
...ECU, 41...distributor, 50...E
It is ATC. Fig. 1 Fig. 4A Fig. 48 Fig. 2B Fig. 7 Fig. 9 Fig. 9D Fig. 9E Fig. 10 Fig. 10A Fig. 10C -MoF Figure 11 (〃)lψKumogi Figure 11? Figure 12A (%) Figure 128 Figure 13A Figure 138 Figure 14 Figure 15

Claims (3)

[Claims] (1) An engine output adjustment member that adjusts the engine output; a means for electronically driving this adjustment member; and a means for determining the drive amount signal of the adjustment member based on the amount of accelerator operation, and driving the adjustment member according to the driving state. An engine control device comprising: means for correcting the value of the drive amount signal; and means for limiting the corrected value of the drive amount signal by a limit value that changes in accordance with the amount of accelerator operation. (2) The engine control device according to claim 1, wherein the limit value includes an upper limit value and a lower limit value. (3) The limit value has a characteristic of gradually increasing as the amount of accelerator operation increases.
The engine control device described in .