JP3228137B2 - Throttle control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine for feedback-controlling an actuator for opening and closing a throttle valve so that the actual opening of the throttle valve becomes a command value set according to the amount of depression of an accelerator pedal or the like. It relates to a throttle control device.

[0002]

2. Description of the Related Art Conventionally, the actual opening degree of a throttle valve is detected, and the detected actual opening degree is used as the amount of depression of an accelerator pedal or the operating state of a vehicle equipped with an internal combustion engine (for example, the slip state of driving wheels). There is known a throttle control device that performs feedback control of an actuator (generally, a DC motor is used) that opens and closes a throttle valve so as to match a command value set in accordance with the above.

However, conventionally, control gains (proportional gain, integral gain,
Since a fixed value that has been set in advance is used as the differential gain, for example, if the response gain with respect to the change in the command value is emphasized and the control gain is set so that the proportional gain is large and the integral gain is small, However, when the actual opening is controlled to be substantially the command value, even if the deviation between the actual opening and the command value is slightly increased, the throttle opening suddenly changes, and the rotation of the internal combustion engine fluctuates greatly, There has been a problem that the driver is uncomfortable or the throttle opening cannot be completely matched with the command value due to the dynamic characteristics of an actuator such as a DC motor. Conversely, for example, if the control gain is set so that the proportional gain is small and the integral gain is large with emphasis on stability at steady state, although the above problem can be solved, the command value suddenly changes and the actual When the deviation between the opening and the command value becomes large, there is a problem that the throttle valve cannot be quickly changed in the direction of the command value, and responsiveness at the time of transition is impaired.

[0004] In order to solve such a problem, the applicant of the present application has determined, according to Japanese Patent Application No. 7-194402, the operating state of the throttle valve based on the deviation between the actual opening of the throttle valve and the command value. It has been proposed to switch the control gain according to the determined operating state.

That is, as shown in FIG. 6A, a sensor value obtained by detecting the throttle opening by a sensor (ie, the actual opening)
If the deviation between the command value and the command value is within a predetermined range (± δ), it is determined that the throttle valve is in a steady state, and the control gain is set to a control gain emphasizing stability.
If the deviation is out of the predetermined range (± δ) and it is necessary to drive the throttle valve quickly in the opening or closing direction, it is determined that the throttle valve is in a transient state,
The control gain is set to a control gain that emphasizes responsiveness.

According to the proposed throttle control device, the throttle control can be performed using the control gain corresponding to the operation state of the throttle valve. To open and close, and achieve both control responsiveness and stability.
By increasing the steady-state integration gain as described above, the throttle opening can be made to completely match the command value when the command value is stable (for example, during idling of the internal combustion engine). it can.

[0007]

However, when the control gain is switched in accordance with the operation state of the throttle valve as in the above proposed throttle control device, the control gain is changed when the operation state of the throttle valve changes. Is switched as it is, the operation of the calculation unit for calculating the control amount cannot keep up with the change of the control gain, and the control signal to the actuator such as the DC motor is temporarily shifted, so that the throttle valve may fluctuate. .

[0008] Such fluctuations of the throttle valve cause no problem when the throttle valve shifts from the steady state to the transient state, but discomfort the driver when the throttle valve shifts from the transient state to the steady state. Will be given. That is, when the throttle valve is in a steady state, such as during idling of the internal combustion engine, the rotation of the internal combustion engine is in a constant state, so the driver notices even a slight rotation fluctuation. Therefore, when the throttle valve changes from a transient state to a steady state, the control gain is suddenly switched from a control gain focusing on responsiveness to a control gain focusing on stability. The rotation of the vehicle fluctuates, giving the driver discomfort.

When the throttle valve changes from a steady state to a transient state, responsiveness is generally required in many cases by a rapid opening / closing operation of an accelerator pedal. Fluctuates greatly.
Therefore, when the throttle valve changes from the steady state to the transient state, even if the throttle valve fluctuates due to rapid switching of the control gain, the driver does not notice and does not give a discomfort to the driver. Also, in this case,
Since responsiveness is required, it is necessary to rapidly change the control gain.

When importance is placed on the stability of the throttle valve in the steady state, a large value is set for the integral gain in the steady state. Since the deviation is large, when the throttle valve changes from the transient state to the steady state, the control gain is switched as it is, and if the integral gain is increased, the integral element accumulated during the transient state causes a transition to the steady state. After the integral element becomes larger than necessary and the throttle valve reaches the command value, the throttle valve is moved by the accumulated force of the integral element, and as shown in FIG. There is also a problem that an overshoot greatly exceeding the value occurs. When the overshoot occurs in this way, the rotation of the internal combustion engine also fluctuates with the overshoot, which gives the driver discomfort.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a throttle control device for an internal combustion engine that switches a control gain in accordance with an operation state of a throttle valve.
It is an object of the present invention to suppress the fluctuation of the throttle valve caused by the switching of the control gain so that the internal combustion engine can always be operated stably.

[0012]

According to a first aspect of the present invention, there is provided a throttle control device for an internal combustion engine, wherein a throttle opening detecting means detects an actual opening of a throttle valve. The control means performs a feedback control of the throttle valve opening / closing actuator using a predetermined control gain so that the detected actual opening coincides with a command value set according to an accelerator pedal depression amount or the like. .

According to the present invention, the operating state determining means determines whether the operating state of the throttle valve is at least a steady state in which a deviation between the actual opening and the command value is within a predetermined range, or It is determined whether or not a transition state is out of the predetermined range. When the result of the determination by the operating state determining means changes from the steady state to the transient state, the control gain setting means changes the control gain used in the control means from the steady state control gain corresponding to the steady state to the transient state. The control gain is quickly switched to the corresponding transient control gain, and conversely, when the determination result of the operating state determining means changes from the transient state to the steady state, the control gain setting means changes the control gain from the transient control gain to the steady state. Slow down to control gain
To change variously.

Therefore, according to the throttle control device of the present invention, when the operating state of the throttle valve changes from the steady state to the transient state, the control gain is promptly switched to the transient control gain, thereby opening the throttle. The control gain can be changed from the transient control gain to the steady-state control when the operating state of the throttle valve changes from the transient state to the steady state. By slowly changing to the gain, it is possible to prevent the rotation fluctuation of the internal combustion engine caused by the rapid switching of the control gain.

[0015] Even when the stability in the steady state is emphasized and the integral gain used in the steady state is set to a large value, the integral gain is changed from a small value to a large value when transitioning from the transient state to the steady state. because gradually to change to, the integral element stored in transient, can be suppressed integral element after the transition to the steady state from becoming larger than necessary, over the throttle opening from the command value Shooting can be prevented.

When the stability in the steady state is emphasized and the integral gain in the steady state is set to a large value as described above, if the integral gain in the transient state is sufficiently reduced, the actual opening of the throttle valve may be reduced. Since the integral element accumulated in the transient state where the deviation between the degree and the command value is large can be reduced, overshoot of the throttle opening that occurs after the transition to the steady state can be prevented more properly.

Thus, according to the present invention, when the operating state of the throttle valve changes from the transient state to the steady state, the control gain is slowly switched to change the throttle opening or to cause overshoot. Since the occurrence can be prevented, the fluctuation of the rotation of the internal combustion engine caused by the switching of the control gain can be suppressed, and the discomfort to the driver can be prevented.

Further, in the throttle control device for an internal combustion engine according to the second aspect, the operating state determining means according to the first aspect determines that a deviation between the actual opening degree of the throttle valve and the command value is within a predetermined range. When the throttle valve changes from the steady state to the transient state, the deviation between the actual opening of the throttle valve and the command value changes from outside the predetermined range to within the predetermined range. Then, when the state where the deviation falls within the predetermined range continues for a predetermined time, it is determined that the transition from the transient state of the throttle valve to the steady state has occurred.

That is, in the throttle control device according to the second aspect, when the deviation between the actual opening degree of the throttle valve and the command value changes from within a predetermined range to outside the predetermined range,
It is determined immediately that the throttle valve has entered the transient state, and the control gain setting means promptly switches the control gain to the transient control gain. Therefore, for example, when the command value changes suddenly and the actual opening greatly deviates from the command value, the throttle valve can be quickly driven in the command value direction, and responsiveness in a transient state can be secured.

When the deviation between the actual opening of the throttle valve and the command value changes from outside the predetermined range to within the predetermined range, the steady state of the throttle valve is determined when the state has continued for a predetermined time or more. By doing so, the start timing of the control gain setting means changing the control gain from the transient control gain to the steady control gain is delayed. As a result, within this delay time, the switching of the control gain can be started after the integral element accumulated during the transient state is sufficiently reduced, and after the transition to the steady state, the throttle opening is reduced from the command value. Overshoot can be more reliably prevented.

As described above, according to the present invention, since the determination of the transition of the throttle valve from the transient state to the steady state is delayed, the command value changes relatively slowly, for example, when the accelerator pedal is operated by the driver. If the deviation between the actual opening of the throttle valve and the command value temporarily falls within a predetermined range, the throttle control can be continued with the control gain in the transient state, The determination between the state and the steady state is alternately switched in a short time, and the control gain is switched accordingly, thereby preventing the internal combustion engine from rotating and fluctuating.

Here, in the present invention, the control gain set by the control gain setting means according to the operating state of the throttle valve includes the operating state of the throttle valve determined by the operating state determining means (in the present invention, at least the steady state). And a transient state), a control gain suitable for control in each state may be appropriately set.
In the case where integral / differential control (PID control) is performed, a proportional gain, an integral gain, and a differential gain are preset as control gains for each operating state of the throttle valve. Is configured to perform proportional / integral control (PI control),
As the control gain, a proportional gain and an integral gain may be set in advance for each operating state of the throttle valve.

Further, the control gain setting means does not necessarily
It is not necessary to switch all the constants (ie, proportional gain, integral gain, and derivative gain) that constitute the control gain.
For example, when the control means is configured to perform PID control, a proportional gain and an integral gain are set as control gains to be switched by the control gain setting means. Regardless, a fixed value may always be used.

In order to improve the responsiveness at the time when the throttle opening greatly deviates from the command value while securing the stability at the steady state where the throttle opening is controlled to substantially the command value, the control gain It is desirable that the setting means is configured as described in claim 3. That is, in the throttle control device for an internal combustion engine according to the third aspect, the control gain setting means according to the first or second aspect sets the proportional gain of the control gain in the transient state as compared with the steady state. The control gain is set to be larger, and the integral gain of the control gain is set to be larger in the steady state than in the transient state.

With this configuration, when the throttle valve is in a transient state, a large proportional gain is used, and the deviation between the actual opening and the command value (deviation:
Large), the throttle valve can be rapidly driven in the direction of the command value (response is ensured), and by using a small integral gain, the integral element accumulated during the transition is reduced, so that the throttle valve is in a steady state. It is possible to suppress overshoot that occurs when switching is performed.

When the throttle valve is in a steady state, a control gain having a small proportional gain and a large integral gain is used, so that even if the deviation between the actual opening degree and the command value slightly changes, the throttle valve greatly changes. In addition, the stability of the control can be ensured, and the throttle opening can be made to coincide with the command value by the integrated element accumulated at this time.

Next, the operating state determining means of the present invention may be configured to simply determine whether the operating state of the throttle valve is a steady state or a transient state. When the throttle valve is in a transient state, the direction in which the throttle valve should be driven (that is, the opening direction or the closing direction) is further determined based on the magnitude relationship between the actual opening degree and the command value.
May be determined. In this case, the control gain setting means switches the control gain in accordance with the operation state of the throttle valve as a control gain for each of an operating state of a steady state, a transient state in the throttle opening direction, and a transient state in the throttle closing direction. The optimal control gain may be set in advance.

According to the first aspect of the present invention, even in the case of such a configuration, the transition from the transient state in the throttle opening direction to the steady state or the transition from the transient state in the throttle closing direction to the steady state. At the time of transition to the state, the control gain is slowly changed, and according to the second aspect of the invention, the determination of the steady state is delayed, so that the above-described effects can be obtained. .

With this configuration, the control gain used for controlling the actuator can be set to a different value between when the throttle valve is driven in the opening direction and when the throttle valve is driven in the closing direction. When the required torque differs depending on the driving direction of the throttle valve, the actuator can be more optimally controlled.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating the overall configuration of a throttle control device for a vehicle internal combustion engine according to the present embodiment.

As shown in FIG. 1, the intake passage 2 of the internal combustion engine 1
Is provided with a throttle valve 3 for controlling the amount of air sucked into the internal combustion engine 1 through the intake passage 2. The throttle valve 3 has a throttle opening detection for detecting a throttle opening (actual opening). A throttle opening sensor 4 is provided as a means. Also, the accelerator pedal 5
An accelerator opening sensor 6 for detecting the amount of depression (hereinafter, also referred to as an accelerator opening) is provided. The signals from the throttle opening sensor 4 and the accelerator opening sensor 6 (the throttle opening signal TH and the accelerator opening signal A
p) is an EC composed mainly of a microcomputer
It is inputted to U (Electronic Control Unit) 10.

The rotation axis of the throttle valve 3
The rotation shaft of a DC motor 12 is connected via a reduction gear 13, and the throttle valve 3 is connected to the DC motor 1.
It is opened and closed by the rotation of 2. That is, in this embodiment, the DC motor 12 is used as the actuator of the throttle valve 3. The DC motor 12 has
A current is supplied from the ECU 10 side. Further, a return spring 14 is provided on the rotation shaft of the throttle valve 3, and the throttle valve 3 is constantly urged to the fully closed side by the return spring 14.

Next, FIG. 2 shows a main configuration of the throttle control device of this embodiment, and FIG. 3 shows a signal flow in a feedback control system constituting the control device. Less than,
The configuration and control operation of the throttle control device of the present embodiment will be described in detail with reference to FIGS.

As shown in FIG. 2, the accelerator opening signal Ap from the accelerator opening sensor 6 and the throttle opening sensor 4
From the throttle opening signal TH from the A / D converter 10a
The A / D conversion is performed, and is taken into the ECU 10.
The ECU 10 calculates a control amount of the DC motor 12 according to these signals, and outputs a PWM (Pulse Width Modulation) signal corresponding to the calculation result to the motor drive circuit 11. Then, a current corresponding to the PWM signal flows from the motor drive circuit 11 to the DC motor 12, and the DC motor 12 generates a rotation torque corresponding to the current value. Open and close the throttle valve 3. In FIG. 2, reference numeral 7 denotes a fully-closed stopper that regulates the fully-closed position of the throttle valve 3.

At this time, as shown in FIG. 3, the ECU 10 determines the command value θcm which is the target opening of the throttle valve 3 based on the A / D conversion value of the accelerator opening signal Ap.
is calculated by the PID control unit 10b using a predetermined control gain (proportional gain Kp, integral gain Ki, and differential gain Kd).
The control amount of the throttle valve 3 is set so that the deviation Δθ between the cmd and the actual opening degree (hereinafter referred to as a sensor value) θth of the throttle valve 3 obtained by A / D conversion of the throttle opening signal TH is eliminated. By calculating (in other words, generating a PWM signal to be output to the motor drive circuit 11), the feedback control for the DC motor 12 is executed.

Incidentally, of the control gains used for feedback control in the PID control section 10b,
The proportional gain Kp that determines the proportional element (Kp △ θ) of the control amount determines the slope of the rise or fall when the throttle valve 3 opens and closes, that is, the response speed. Therefore, if this proportional gain Kp is fixed to a large value, the response speed of the throttle valve 3 becomes faster, but the overshoot as a reaction increases, and oscillation tends to occur when the throttle opening is kept constant.

Further, the integral element of the control amount (Ki · ∫ △ θ)
Is determined so as to reduce the deviation Δθ between the command value θcmd of the throttle valve 3 and the sensor value θth. Therefore, when the integral gain Ki is fixed to a large value, when the sensor value θth converges around the command value θcmd, the sensor value θth can be made to match the command value θcmd, but the sensor value θth and the command value θc
When the deviation Δθ of md is large, this large deviation Δθ
Is accumulated, the integral factor becomes too large, and it takes time for the sensor value θth to largely hunt around the command value θcmd and to converge the sensor value θth to the command value θcmd.

Further, a differential element (Kd · d △ θ /
The differential gain Kd that determines dt) determines the final convergence speed related to the response speed in opening and closing the throttle valve 3. Therefore, when the differential gain increases, the response speed of the throttle valve 3 decreases, but on the other hand, the overshoot when the throttle opening of the throttle valve fluctuates decreases.

Therefore, in the throttle control device of the present embodiment, it is determined whether the throttle valve 3 is in the steady state or the transient state based on the deviation Δθ between the sensor value θth and the command value θcmd, and the determination is made. Depending on each operating condition,
By switching between the proportional gain Kp and the integral gain Ki among the control gains used for calculating the control amount in the PID control unit 10b, it is possible to achieve both the responsiveness and the stability of the throttle control.

Hereinafter, the control gain (proportional gain K)
The control process executed by the ECU 10 for switching p and the integral gain Ki) will be described with reference to the flowchart shown in FIG. This process is a process that is repeatedly executed by the ECU 10 at a predetermined time (for example, every 2 msec.).
Represents the step), the throttle opening command value θ
The cmd and the sensor value θth are read. And the following S
At 120, it is determined whether or not the absolute value of the deviation Δθ between the read command value θcmd and the sensor value θth is equal to or less than a predetermined angle (2 ° in this embodiment) in the rotation angle of the throttle valve 3. .

If the absolute value of the deviation exceeds 2 °, it is determined that the transient state is such that the throttle valve 3 should be driven promptly, and the flow shifts to S170, where the proportional gain Kp and the integral gain Ki are determined. After that, a preset value in a transient state (Kp = 12, Ki = 4 in this embodiment) is set, and in subsequent S180, the counter CNT used in the processing described later is cleared to a value of 0. Then, the process is temporarily terminated.

In FIG. 4, the suffix n added to the proportional gain Kp and the integral gain Ki represents the value of each gain set in the current processing, and the suffix (n-1) represents the current processing execution. This represents the value of each gain that has already been set before.
On the other hand, if it is determined in S120 that the absolute value of the deviation is equal to or less than 2 °, the flow shifts to S130, where the absolute value of the deviation is 2 °.
°, the counter CNT is incremented (+1) in order to count the duration of the state where the temperature has become less than or equal to
It is determined whether or not the state has continued for a predetermined time (40 msec. In the present embodiment) after the value of the counter CNT is equal to or more than a predetermined value and the absolute value of the deviation has become 2 ° or less. I do.

Then, in S140, the absolute value of the deviation is 2
If it is determined that the state does not continue for 40 msec. Or more after the temperature has decreased to less than or equal to 0 °, the process ends immediately. Is determined to have continued for more than 40 msec., It is determined that the operating state of the throttle valve 3 has transitioned from the transient state to the steady state, and the routine shifts to S150. Therefore, in this embodiment, even if the absolute value of the deviation becomes 2 ° or less, if the state does not continue for more than 40 msec., It is determined that the transition of the throttle valve 3 from the transient state to the steady state. During this period, the control gain (Kp = 12, Kp) in the transient state previously set in S170
i = 4), the throttle control is executed.

Next, at S150, which is executed when it is determined that the throttle valve 3 is in the steady state, the updated values tKp and tKi for switching the proportional gain Kp and the integral gain Ki to values corresponding to the steady state. As
Each of them is set to a predetermined value (tKp = 4, tKi = 12 in this embodiment) different from the value in the transient state.

In S160, the proportional gain Kp and the integral gain Ki used for the throttle control are calculated using the following equations (1) and (2), respectively, and the calculation results are used for the subsequent throttle control. After setting the proportional gain Kp and the integral gain Ki, the process is temporarily terminated.

Kpn = Kp (n-1) + (tKp-Kp (n-1)) / 16 (1) Kin = Ki (n-1) + (tKi-Ki (n-1)) / 16 (2) That is, in this embodiment, in S160, the above (1),
By updating the proportional gain Kp and the integral gain Ki using the equation (2), when the transition of the operating state of the throttle valve 3 from the transient state to the steady state is determined, the proportional gain Kp and the integral gain Ki are changed. Instead of promptly switching to values (update values tKp and tKi) suitable for throttle control in a steady state, instead of changing the values tKp and tKi and the gains Kp and Ki calculated last time to 1/16, Then, the respective gains Kp, Ki are gradually updated to predetermined values tKp and tKi suitable for throttle control in a steady state by a so-called smoothing process of updating the gains Kp, Ki at predetermined time intervals.
Get closer to each other.

As described above, in the throttle control device of the present embodiment, the control used for generating the control amount (specifically, the PWM control signal output to the motor drive circuit 11) by the PID control unit 10b. Among the gains, the proportional gain Kp and the integral gain Ki are switched according to the operating state of the throttle valve 3 (steady state and transient state). In this switching, as shown in FIG. 5, when the transient state of the throttle valve 3 is determined,
When each control gain Kp, Ki is set to a predetermined value (Kp = 12, Ki = 4) corresponding to the transient state as it is, and the steady state of the throttle valve 3 is determined, the above equation is used.
Using (1) and (2), each control gain Kp, Ki is changed from a predetermined value (Kp = 12, Ki = 4) suitable for a transient state to a predetermined value (Kp = 4, Ki = 4) suitable for a steady state. 12) gradually <br/> changed to.

Therefore, according to the present embodiment, when the operating state of the throttle valve 3 changes from a steady state with a small deviation Δθ to a transient state with a large deviation Δθ, the control gains Kp and Ki are quickly increased. By switching to a value suitable for the transient state, the responsiveness of the sensor value θth to the command value θcmd (in other words, the responsiveness of the throttle control) can be ensured. When the operating state of the throttle valve 3 changes from the transient state to the steady state, the control gain K
By gradually changing p and Ki to values suitable for the steady state, when the throttle valve 3 enters the steady state due to idling operation of the internal combustion engine or the like, the throttle opening fluctuates, and the rotation of the internal combustion engine 1 is changed. It is possible to prevent the fluctuation from occurring and giving the driver discomfort.

In this embodiment, the proportional gain Kp is large (value 12) in the transient state, and is large in order to secure both the response in the transient state of the throttle valve 3 and the stability in the steady state. Although the integral gain Ki is set to be small (value 4) in the state and the integral gain Ki is set to be large (value 12) in the steady state and small (value 4) in the transient state, the operation state of the throttle valve 3 is changed to the transient state. When the throttle valve 3 enters the steady state, the integral gain Ki changes slowly to a large value when the throttle valve 3 enters the steady state. The integral element does not become too large, and the occurrence of the overshoot shown in FIG. 6B can be prevented.

In particular, in this embodiment, when the deviation Δθ between the sensor value θth and the command value θcmd falls within a predetermined range (that is, the absolute value of the deviation Δθ is 2 ° or less), the throttle valve 3 is not determined, the steady state is determined when the state has continued for a predetermined time (40 msec.) Or more. During this period, the transient state in which the deviation Δθ is large is determined. The accumulated integral element can be made sufficiently small, and then, when a steady state is determined and the integral gain Ki is increased, the integral element becomes unnecessarily large and overshoot occurs. Can be prevented more reliably.

That is, when the steady state is determined when the deviation Δθ between the sensor value θth and the command value θcmd is within ± 2 °, the increase of the integral gain Ki after the determination of the steady state is made. Depending on the method, the integral element accumulated in the transient state may cause the integral element to become too large, causing overshoot.

In order to prevent overshoot only by changing the integral gain Ki, the integral gain Ki may be increased more slowly. However, in this case, the sensor value θth is instructed after entering the steady state. It takes time to match the value θcmd. On the other hand, to shorten this time, the determination value of the deviation △ θ for determining the steady state is, for example,
It may be smaller than ± 2 °, such as ± 1 ° or ± 0.5 °. However, when this determination value is reduced, even if the throttle valve slightly moves due to disturbance or the like during the steady state (for example, only moves 0.6 ° or 1.1 °), the transient state is determined and the control gain is reduced. Will change it.

However, as in this embodiment, the sensor value θt
h and the command value θcmd fall within ± 2 °, which is the determination value of the steady state, and the state becomes a predetermined delay time (4
0 msec.), The steady state is determined, and the integral gain Ki is gradually increased. Thus, it is possible to eliminate the overshoot while preventing erroneous determination of the transient state due to disturbance or the like. become able to.

The above-described values of the proportional gain Kp and the integral gain Ki, and the determination values (2
°), the delay time (40 msec.) And the like may be appropriately set according to the throttle control system of the internal combustion engine to which the present invention is applied, and the above values are not absolute.

In the present embodiment, the processing of S110 to S140 and S180 in FIG.
4 and FIG.
The processing of S150, S160, and S170 in
This corresponds to the control gain setting means described in claims 1 and 3.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and can take various forms. For example, in the above embodiment, among the control gains used in the PID control unit 10b, the differential gain Kd has been described as using a fixed value set in advance.
May be switched according to the operating state of the throttle valve 3.

Further, in the above-described embodiment, the description has been made on the assumption that the operating state of the throttle valve 3 is determined in two kinds of operating states, a steady state and a transient state, and the control gain is switched in accordance with the result of the determination. For example, a transient state when the throttle valve 3 is driven in the closing direction and a transient state when the throttle valve 3 is driven in the opening direction are determined as the operating states of the throttle valve 3, and the optimum state is determined for each transient state. If a proper control gain is used, the throttle valve 3 can be opened and closed more favorably.

In the above embodiment, the DC motor 12 is used as an actuator for opening and closing the throttle valve 3.
However, as this actuator, a rotary actuator other than the DC motor 12 can be used, or a linearly-moving actuator such as an electromagnetic solenoid can be used.

In the above embodiment, the throttle opening command value θcmd has been described as being set based on the accelerator opening signal Ap corresponding to the amount of depression of the accelerator pedal 5. In order to realize traction control that suppresses the output of the internal combustion engine 1 when an acceleration slip occurs, a separate throttle opening command value is generated according to the slip ratio of the drive wheels when the acceleration slip occurs. For the throttle control, the generated command value may be used in preference to the command value corresponding to the depression amount of the accelerator pedal 5.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall configuration of a throttle control device for a vehicle internal combustion engine according to an embodiment.

FIG. 2 is an explanatory diagram illustrating a main configuration of a throttle control device according to an embodiment.

FIG. 3 is an explanatory diagram showing a signal flow in a feedback control system that constitutes the throttle control device of the embodiment.

FIG. 4 is a flowchart illustrating a control process executed for switching a control gain in the ECU of the embodiment.

FIG. 5 is a time chart for explaining a control gain switching operation in the ECU of the embodiment.

FIG. 6 is an explanatory diagram for explaining a problem when the control gain is switched as it is in accordance with the operation state of the throttle valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Intake passage 3 ... Throttle valve 4 ... Throttle opening sensor 5 ... Accelerator pedal 6 ... Accelerator opening sensor 10a ... A / D converter 10b ... PID control part 11 ... Motor drive circuit 1
2 ... DC motor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 41/10-41/14 F02D 9/02 F02D 11/10 F02D 45/00

Claims (3)

(57) [Claims] 1. A throttle opening detecting means for detecting an actual opening of a throttle valve, wherein the detected actual opening of the throttle valve is a command value set according to a depression amount of an accelerator pedal or the like. ,
Control means for feedback-controlling an actuator for opening and closing the throttle valve using a predetermined control gain. A throttle control apparatus for an internal combustion engine, comprising: an operating state of the throttle valve, at least the actual opening degree and the command. Operating state determining means for determining whether the deviation from the value is in a steady state within a predetermined range or a transient state in which the deviation is out of the predetermined range; and When changing from the steady state to the transient state, the control gain is quickly switched from the steady state control gain corresponding to the steady state to the transient state control gain corresponding to the transient state,
Control gain setting means for gradually changing the control gain from the transient control gain to the steady control gain when the determination result changes from the transient state to the steady state. Control device for an internal combustion engine. 2. The method according to claim 1, wherein when the deviation between the actual opening degree and the command value changes from within the predetermined range to outside the predetermined range, the operating state determination unit changes the throttle valve from a steady state to a transient state. The transition is determined promptly, and when the deviation between the actual opening degree and the command value changes from outside the predetermined range to within the predetermined range, the state where the deviation is within the predetermined range has continued for a predetermined time. 2. The throttle control device for an internal combustion engine according to claim 1, wherein a transition from a transient state to a steady state of the throttle valve is determined at a point in time. 3. The control gain setting means sets a proportional gain of the control gain so that the proportional gain in the transient state is larger than that in the steady state, and sets an integral gain in the control gain. 3. The throttle control device for an internal combustion engine according to claim 1, wherein the setting is such that the steady state is larger than the transient state.