JP2927212B2 - 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 a throttle control device for an internal combustion engine that controls a degree of opening of a throttle valve by driving a direct current (DC) motor in accordance with an amount of depression of an accelerator pedal.

[0002]

2. Description of the Related Art Conventionally, there has been known a throttle control device for an internal combustion engine called an “electronic throttle system” that controls a degree of opening of a throttle valve by driving a DC motor in accordance with an amount of depression of an accelerator pedal.

In this throttle control device for an internal combustion engine, DC is controlled in accordance with a signal from an accelerator opening sensor which detects an accelerator opening corresponding to the amount of depression of an accelerator pedal.
When a current is supplied to the motor and the DC motor is driven, the throttle valve is opened and closed to control the amount of intake air. At this time, proportional / integral / differential control (hereinafter simply referred to as “DC”) is performed on the DC motor so that the deviation between the signal from the throttle opening sensor for detecting the throttle opening of the throttle valve and the signal from the accelerator opening sensor is eliminated. PID control ”).

[0004] Here, as a prior art document relating to a throttle control device for an internal combustion engine, there is Japanese Patent Application Laid-Open No. 3-19413.
No. 6 is known.

In this vehicle, in a vehicle equipped with an internal combustion engine equipped with an exhaust turbocharger, the control gain is adjusted so that there is no difference in the response speed between the low load region and the high load region with respect to the accelerator operation amount. There is disclosed a technique for changing the configuration to eliminate the uncomfortable feeling given to the driver. The control gain referred to here is for calculating the target opening, and is a gain for controlling the DC motor itself to obtain the target opening.

[0006]

In the throttle opening control in the above-mentioned prior art document, it was premised that the actual opening of the throttle valve coincides with the calculated target opening. In general, in the throttle opening control using a DC motor, there is a problem that the actual opening of the throttle valve and the target opening do not match due to the dynamic characteristics of the DC motor, and in particular, do not match during a transition.

For example, in a system in which the throttle valve is biased by a return spring, the opening of the throttle valve of the DC motor is controlled against the biasing force of the return spring. Then, when the throttle valve is driven to the open side or the close side at a high speed or held at a constant opening, the load of the DC motor is greatly different each time. For this reason, when a fixed control gain is used in the PID control regardless of the operation state of the throttle valve, there has been a problem that a moderate control gain has to be used and optimum tuning cannot be performed.

Accordingly, the present invention has been made to solve such a problem, and improves the responsiveness of the open side and the closed side and reduces the deviation of the actual opening from the target opening in a steady state. It is an object of the present invention to provide a throttle control device for an internal combustion engine that can optimize all operations of a throttle valve by DC motor control according to each situation.

[0009]

According to a first aspect of the present invention, there is provided a throttle control apparatus for an internal combustion engine which controls a degree of opening of a throttle valve by driving a DC motor in accordance with an amount of depression of an accelerator pedal. An actual opening detecting means for detecting an actual opening of the throttle valve as an actual opening, a target opening set in accordance with a depression amount of the accelerator pedal, and the actual opening detected by the actual opening detecting means. Operating state determining means for determining an operating state of the throttle valve based on a deviation from the actual opening degree; and control gain setting means for setting a control gain in accordance with the operating state determined by the operating state determining means. Is what you do.

According to a second aspect of the present invention, in the throttle control device for an internal combustion engine according to the first aspect of the present invention, the operating state determining means determines that the throttle valve is closed when an absolute value of a deviation between the target opening and the actual opening is within a predetermined value. When the valve is in a steady state and the deviation between the target opening and the actual opening exceeds a predetermined value, the throttle valve is in a transition state in the opening direction, and the deviation between the target opening and the actual opening is When the value is less than the negative predetermined value, it is determined that the throttle valve is in the transition state in the closing direction.

According to a third aspect of the present invention, there is provided a throttle control device for an internal combustion engine, which controls a degree of opening of a throttle valve by driving a DC motor in accordance with an amount of depression of an accelerator pedal. It comprises a transition condition detecting means for detecting a predetermined transition condition in which a state transitions, and a control gain setting means for setting a control gain according to the predetermined transition condition detected by the transition condition detecting means. .

According to a fourth aspect of the present invention, there is provided a throttle control device for an internal combustion engine, wherein the transition condition detecting means according to the third aspect is configured such that the predetermined transition condition is such that the throttle valve is open to closed, closed to open, and open. There are six settings, from the state to the steady state, from the steady state to the open state, from the closed state to the steady state, and from the steady state to the closed state. Contract
Throttle control for an internal combustion engine according to claim 1 and claim 3.
Further, the control gain setting means changes and sets the control gain after a predetermined time has passed when the throttle valve transitions from an open state to a steady state or from a closed state to a steady state.

[0013]

In the throttle control device for an internal combustion engine according to the present invention, the target opening set by the operating state determining means in accordance with the depression amount of the accelerator pedal and the actual throttle valve detected by the actual opening detecting means. The operating state of the throttle valve is determined based on the deviation from the opening, and the control gain is set by the control gain setting means according to the operating state. As described above, the control gain is set according to the operating state of each of the throttle valves.

According to a second aspect of the present invention, when the absolute value of the deviation between the target opening and the actual opening is within a predetermined value, the throttle valve is in a steady state. When the deviation between the target opening and the actual opening exceeds a predetermined value, the throttle valve is in a transient transition state in the opening direction, and when the deviation between the target opening and the actual opening is less than a negative predetermined value, the throttle valve is closed. It is determined that the transition state is a transitional state in the direction. Thus, the operating state of the throttle valve is determined from the target opening and the actual opening.

According to a third aspect of the present invention, the control gain is set by the control gain setting means in accordance with a predetermined transition condition in which the operating state of the throttle valve is detected by the transition condition detection means. You. Thus, the control gain corresponding to the predetermined transition condition is appropriately set.

In the throttle control device for an internal combustion engine according to a fourth aspect of the present invention, the transition condition detecting means according to the third aspect includes a predetermined transition condition that the throttle valve is open to closed, closed to open, open to steady, There are six settings, from the steady state to the open state, from the closed state to the steady state, and from the steady state to the closed state. The state transition between the three states of the throttle valve (open state, closed state, steady state) is accurately performed. Can be detected.

The internal combustion engine according to claim 1 and claim 3
Further, in the throttle control device, when the control gain setting means makes a transition from the open state to the steady state or from the closed state to the steady state, the control gain is changed and set after a predetermined time has elapsed. For this reason, even if the deviation between the target opening and the actual opening sharply changes, the control gain is changed after a predetermined time.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on specific embodiments.

FIG. 1 is a schematic diagram showing the entire configuration of a throttle control device for an internal combustion engine according to one embodiment of the present invention.

In FIG. 1, an internal combustion engine 1 has an intake passage 2
The air is supplied through. The throttle valve 3 is provided in the middle of the intake passage 2, and the throttle valve 3 is provided with a throttle opening sensor 4 for detecting a throttle opening. The accelerator pedal 5 is provided with an accelerator opening sensor 6 for detecting the accelerator opening.

An ECU (Electronic Control Unit) 10 receives a throttle opening signal TH from a throttle opening sensor 4 and an accelerator opening signal Ap from an accelerator pedal 5. A current is supplied to the DC motor 12 as an actuator from the ECU 10 side. Reference numeral 13 denotes a DC motor 12 and a throttle valve 3
And a return spring 14 which constantly urges the throttle valve 3 to the fully closed side.

Next, a description will be given with reference to FIG. 2 showing a main configuration of a throttle control device for an internal combustion engine according to an embodiment of the present invention, and FIG. 3 showing a signal flow in feedback control.

In FIG. 2, an accelerator opening signal Ap from an accelerator opening sensor 6 corresponding to the amount of depression of an accelerator pedal 5 and a throttle opening signal from a throttle opening sensor 4 corresponding to the throttle opening of the throttle valve 3. TH is A / D converted by the A / D converter 10a and the ECU 10
Is input to A PWM (Pulse Width Modulation: Pulse Width Modulation) signal is output from the ECU 10 to the motor drive circuit 11 according to these signals. Then, a current flows from the motor drive circuit 11 to the DC motor 12, and the DC motor 12 is driven to open and close the throttle valve 3 via the reduction gear train 13. 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.
Then, the actual throttle opening θth (hereinafter simply referred to as “actual opening”) θth calculated based on the throttle opening signal TH of the throttle opening sensor 4 corresponding to the throttle opening of the throttle valve 3 and the accelerator pedal 5 Accelerator opening signal A of accelerator opening sensor 6 corresponding to the accelerator opening
The throttle opening command value (hereinafter simply referred to as “command value”) as the target opening of the throttle valve 3 calculated based on p
Feedback control is performed on the DC motor 12 via the motor drive circuit 11 by the PID control by the PID control circuit 10b so that the deviation from θcmd is eliminated.

Next, a P (proportional) term in the PID control,
The relationship between the P-term gain, I-term gain, and D-term gain, which are the control constants of the I (integral) term and the D (differential) term, and the control characteristics of the throttle valve 3 will be described.

The P-term gain controls the rising or falling slope in opening and closing the throttle valve 3, that is, the response speed. Therefore, the response speed of the throttle valve 3 increases as the P-term gain increases,
Overshoot as a reaction increases, and oscillation tends to occur if the throttle opening is to be kept constant.

The I-term gain is determined by the throttle valve 3
Is controlled so as to reduce the deviation between the command value θcmd and the actual opening degree θth. Therefore, when the I-term gain increases, the behavior of the throttle valve 3 increases, and oscillation tends to occur when the throttle opening is kept constant.

The D-term gain controls the final convergence speed related to the response speed in opening and closing the throttle valve 3. Therefore, as the D-term gain increases, the response speed of the throttle valve 3 decreases, but on the other hand,
Overshoot of the throttle valve 3 when the throttle opening varies is reduced.

For this reason, in the PID control of the throttle opening of the ECU 10 used in the throttle control device for an internal combustion engine according to the present embodiment, for example, as shown in a time chart showing the transition of the throttle opening in FIG. By comparing the deviation between the command value θcmd and the actual opening degree θth of the throttle valve 3 with a steady state determination value ± δ as a variation allowable value,
Two phases (Phase: state), that is, phase PH1: open → (the following “→” is used in the meaning of “from”) closed transient state, phase PH2: closed → open transient state, phase P
H3: Divided into the steady state, and each phase PH1, PH
2. The control gains Kp (P-term gain), Ti (I-term gain), and Td (D-term gain) of the PID control circuit 10b at PH3 are changed. That is, for the phase PH1, each control gain Kp1, Ti1, Td of the PID control circuit 10b is used.
1. Each of the control gains Kp2, Ti2, Td2 of the PID control circuit 10b for the phase PH2, and each of the control gains Kp3, Ti3, Td3 of the PID control circuit 10b for the phase PH3.
Is set. In the following description, each control gain set for each phase is described as Kp, Ti, Td without distinction. The steady state determination value + δ is an open-side threshold for determining a state transition in a transition state from a closed state to an open state, and −δ.
Is a threshold value on the closed side for determining a state transition in a transition state from open to closed.

Next, the ECU 10 used in the throttle control apparatus for an internal combustion engine according to one embodiment of the present invention.
Phase PH in PID control of throttle opening
The processing procedure for setting the control gains of 1, PH2 and PH3 will be described with reference to the flowchart of FIG.

First, in step S101, a throttle opening command value θcmd and an actual opening θth for the throttle valve 3 are read. Next, the process proceeds to step S102, and it is determined whether or not the absolute value of the deviation between the command value θcmd and the actual opening degree θth is equal to or less than a predetermined steady state determination value δ as a variation allowable value. When the determination condition of step S102 is satisfied, the process proceeds to step S103, and the counter CNT is incremented by "1". Next, the process proceeds to step S104, and it is determined whether the value of the counter CNT is equal to or greater than a predetermined value α for counting a predetermined time. If the determination condition in step S104 is not satisfied and the predetermined time has not elapsed, the present routine ends. On the other hand, when the determination condition of step S104 is satisfied,
The routine proceeds to 105, where the control gains Kp, Ti, Td for the PID control in the phase PH2 are set. Next, step S106
The routine is terminated after the counter CNT is returned to 0.

Here, when the determination condition of step S102 is not satisfied, the process proceeds to step S107, and the deviation (θcmd-θth) between the command value θcmd and the actual opening degree θth is set in the preset open-to-close transition state. It is determined whether it is less than the threshold value on the closed side -δ. When the determination condition of step S107 is not satisfied, the process proceeds to step S108, and the process is closed →
After the control gains Kp, Ti, and Td of the PID control of the phase PH1 in the open transition state are set, the routine ends. Further, when the determination condition in step S107 is satisfied, the process proceeds to step S109, and after the control gains Kp, Ti, and Td of the PID control of the phase PH3 in the open-to-close transition state are set, the present routine ends. .

FIG. 6 is a time chart showing the effect of the PID control of the throttle opening when the present throttle control device is applied, in comparison with the conventional partial PID control.

Conventionally, as shown in FIG. 6 (b), if optimization is performed only in the transition from the opening to the closing, an overshoot occurs in the transition from the closing to the opening, as shown in FIG. 6 (c). ,
If the optimization is performed only in the closed-to-open transition state, a response delay occurs in the open-to-closed transition state. As shown in FIG. And a response delay in the transition from open to closed.
On the other hand, in the PID control of the throttle opening to which the present throttle control device is applied, as shown in FIG.
The optimization is performed in all of the phases PH1 in the transition from the closed state to the open state, PH3 in the transient state from the open state to closed state, and PH2 in the steady state.

As described above, the throttle control device for an internal combustion engine according to the present embodiment controls the opening of the throttle valve 3 by driving the DC motor 12 in accordance with the depression amount of the accelerator pedal 5. Actual opening degree detecting means achieved by the ECU 10 for detecting the actual opening degree of the actual opening degree as the actual opening degree θth, a command value θcmd as a target opening degree set according to the depression amount of the accelerator pedal 5, and the actual opening degree. Deviation from the actual opening degree θth (θcmd −
θth), based on the operating state determination means achieved by the ECU 10 for determining the phase PH1, the phase PH2, and the phase PH3 as the operating state of the throttle valve 3, and the operating state determined by the operating state determining means. PI
ECU 1 for setting each control gain Kp, Ti, Td of D control
0, and a control gain setting means achieved at 0. This can be regarded as the first embodiment of the present invention.

Therefore, the deviation (θcmd−θ) between the command value θcmd set by the operation state determining means in accordance with the depression amount of the accelerator pedal 5 and the actual opening degree θth of the throttle valve 3 detected by the actual opening degree detecting means. θth), the phases PH1 and PH2 as the operating state of the throttle valve 3
Alternatively, the phase PH3 is determined, and the control gain setting means sets the PH according to the operation state (phases PH1, PH2, PH3).
Each control gain Kp, Ti, Td of the ID control is set. As described above, by setting the respective control gains Kp, Ti, Td of the PID control appropriate for the respective operating states (phases PH1, PH2, PH3) of the throttle valve 3, all the operations of the throttle valve 3 are performed. Can be optimized.

In the throttle control device for an internal combustion engine according to the present embodiment, the operating state determining means achieved by the ECU 10 determines that the absolute value | of the deviation between the command value θcmd and the actual opening degree θth.
When θcmd−θth | is equal to or less than a predetermined value δ, the throttle valve 3 is in a steady state, and when the deviation (θcmd−θth) between the command value θcmd and the actual opening degree θth exceeds a predetermined value + δ, the throttle valve 3 is opened. In the transition state, when the deviation (θcmd−θth) between the command value θcmd and the actual opening degree θth is smaller than a negative predetermined value −δ, it is determined that the throttle valve 3 is in the transition state in the closing direction. Can be the embodiment of claim 2.

Therefore, the command value θ is determined by the operation state determining means.
When the absolute value | θcmd−θth | of the deviation between cmd and the actual opening θth is equal to or smaller than a predetermined value δ, the throttle valve 3 is in a steady state, and the deviation between the command value θcmd and the actual opening θth (θcmd−
θth) exceeds the predetermined value + δ, the throttle valve is in a transition state in the opening direction, and the command value θcmd and the actual opening degree θth
Is smaller than the negative predetermined value -δ, it is determined that the throttle valve 3 is in the transition state in the closing direction. Thus, the operation state of the throttle valve 3 can be determined from the command value θcmd and the actual opening degree θth.

The throttle control device for an internal combustion engine according to the present embodiment has a function of D
A control means for controlling a degree of opening of the throttle valve 3 by driving the C motor 12, wherein the ECU 10 detects a predetermined transition condition under which an operation state of the throttle valve 3 transits; Control gain setting means achieved by the ECU 10 for setting each control gain Kp, Ti, Td of the PID control in accordance with the predetermined transition condition detected by the means. Embodiment can be adopted.

Accordingly, the control gain setting means sets the respective control gains Kp, Ti, Td of the PID control in accordance with the predetermined transition condition in which the operation state of the throttle valve 3 detected by the transition condition detection means transitions. As described above, by appropriately setting the control gains Kp, Ti, and Td of the PID control corresponding to the predetermined transition condition, all the operations of the throttle valve 3 can be optimized.

Further, in the throttle control device for an internal combustion engine according to the present embodiment, the transition condition detecting means achieved by the ECU 10 includes the throttle valve 3 as the predetermined transition condition.
Are set from the open state to the closed state, from the closed state to the open state, from the open state to the steady state, from the steady state to the open state, from the closed state to the steady state, from the steady state to the closed state, and six are set. This can be referred to as the fourth embodiment.

As described above, the transition condition detection means sets the throttle valve 3 from the open state to the closed state as the predetermined transition condition.
There are six settings: from the closed state to the open state, from the open state to the steady state, from the steady state to the open state, from the closed state to the steady state, and from the steady state to the closed state.
The state transition between the two states (open state, closed state, steady state) can be accurately detected.

Further, in the throttle control apparatus for an internal combustion engine according to the present embodiment, the control gain setting means achieved by the ECU determines whether the throttle valve 3 changes from the open state to the steady state or from the closed state to the steady state. , After a predetermined time period in which the counter CNT becomes equal to or more than α,
The control gains Kp, Ti, Td of the control are changed and set, and this can be used as the first or third embodiment.

As described above, when the control gain setting means changes the throttle valve 3 from the open state to the steady state or from the closed state to the steady state, the control gains Kp, Ti, Td of the PID control are passed after a predetermined time has elapsed. Is changed and the deviation between the command value θcmd and the actual opening degree θth (θcmd−θ
Even if th) changes rapidly, the behavior of the throttle valve 3 does not become unnatural.

By the way, in each phase P of the above-described embodiment,
The control gains Kp, Ti, and Td of the PID control set in accordance with H1, PH2, and PH3 are not limited to these in implementing the present invention. The phase constant may be set so as to optimize the time constant so as to optimize the steady-state characteristics in the phase PH2, and the mechanical time constant in the closed side may be optimized in the phase PH3.

[0046]

As described above, according to the throttle control apparatus for an internal combustion engine of the first aspect, the target opening and the actual opening detecting means set by the operating state determining means in accordance with the depression amount of the accelerator pedal. The operating state of the throttle valve is determined on the basis of the deviation from the actual opening of the throttle valve detected in step (1), and the control gain is set by the control gain setting means according to the operating state. Thereby, a control gain is set according to each operation state of the throttle valve, so that all operations of the throttle valve can be optimized.

According to the throttle control apparatus for an internal combustion engine of the second aspect, in addition to the effect of the first aspect, when the absolute value of the deviation between the target opening and the actual opening is within a predetermined value by the operating state determining means, When the throttle valve is in a steady state and the deviation between the target opening and the actual opening exceeds a predetermined value, the throttle valve is in a transition state in the opening direction, and the deviation between the target opening and the actual opening is a negative predetermined value. If it is less than the predetermined value, it is determined that the throttle valve is in the transition state in the closing direction. Thus, the operating state of the throttle valve can be determined from the target opening and the actual opening.

According to the throttle control device for an internal combustion engine of the third aspect, the control gain is set in accordance with the predetermined transition condition in which the operation state of the throttle valve detected by the transition condition detection means transitions by the control gain setting means. Is done. As a result, the control gain corresponding to the predetermined transition condition is appropriately set, and all operations of the throttle valve can be optimized.

According to the throttle control device for an internal combustion engine of the fourth aspect, in addition to the effect of the third aspect, three states (open state) of the throttle valve according to the six predetermined transition conditions set by the transition condition detecting means. , Closed state, steady state) can be accurately detected.

The internal combustion engine according to claim 1 and claim 3
According to the throttle control device, when the control gain setting means changes the throttle valve from the open state to the steady state or from the closed state to the steady state, the control gain is changed and set after a predetermined time has elapsed. The unnatural behavior of the throttle valve can be prevented even for a sudden change in the deviation between the opening and the actual opening.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire configuration of a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a main configuration of a throttle control device for an internal combustion engine according to one embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a signal flow in a throttle control device for an internal combustion engine according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram showing division of phases in a throttle control device for an internal combustion engine according to one embodiment of the present invention.

FIG. 5 is a flowchart showing a processing procedure for setting a control gain of each phase of an ECU used in a throttle control device for an internal combustion engine according to one embodiment of the present invention.

FIG. 6 is a time chart showing a transition state of a throttle opening in a throttle control device for an internal combustion engine according to one embodiment of the present invention, as compared with a conventional example.

[Explanation of symbols]

 Reference Signs List 1 internal combustion engine 3 throttle valve 4 throttle opening sensor 5 accelerator pedal 6 accelerator opening sensor 10 ECU (electronic control device) 10b PID control circuit 12 DC motor

Claims (4)

(57) [Claims] 1. A throttle control device for an internal combustion engine that controls a degree of opening of a throttle valve by driving a DC motor in accordance with an amount of depression of an accelerator pedal, wherein the actual degree of opening of the throttle valve is detected as an actual degree of opening. Opening degree detecting means; and determining an operating state of the throttle valve based on a deviation between a target opening degree set in accordance with a depression amount of the accelerator pedal and the actual opening degree detected by the actual opening degree detecting means. Operating state determining means, and control gain setting means for setting a control gain according to the operating state determined by the operating state determining means.
The control gain setting means opens the throttle valve.
Transition from state to steady state or closed to steady state
Sometimes, the control gain is changed after a predetermined time has elapsed.
A throttle control device for an internal combustion engine, wherein the throttle control device is further set . 2. The operating state determining means, wherein when the absolute value of the deviation between the target opening and the actual opening is within a predetermined value, the throttle valve is in a steady state;
When the deviation between the target opening and the actual opening exceeds a predetermined value, the throttle valve is in a transition state in the opening direction, and the deviation between the target opening and the actual opening is less than a negative predetermined value. The throttle control device for an internal combustion engine according to claim 1, wherein it is determined that the throttle valve is in a transition state in the closing direction at the time of (i). 3. A throttle control device for an internal combustion engine that controls a degree of opening of a throttle valve by driving a DC motor in accordance with an amount of depression of an accelerator pedal, wherein a predetermined transition condition in which an operation state of the throttle valve transitions is detected. Transition condition detecting means, and control gain setting means for setting a control gain in accordance with the predetermined transition condition detected by the transition condition detecting means , wherein the control gain setting means is configured to open the throttle valve.
Also the steady state transitions from the closed state to the steady state from the state
Sometimes, the control gain is changed after a predetermined time has elapsed.
A throttle control device for an internal combustion engine, wherein the throttle control device is further set . 4. The transition condition detecting means, wherein the predetermined transition condition is that the throttle valve is in an open state to a closed state, a closed state to an open state, an open state to a steady state, a steady state to an open state, and a closed state to a steady state. The throttle control device for an internal combustion engine according to claim 3, wherein six transition conditions when the state changes from the steady state to the closed state are detected.