JP3460383B2 - Throttle control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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 a depression amount of an accelerator pedal. It is. 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] By the way, the above-mentioned P
The control constants of the P (proportional) term, the I (integral) term, and the D (differential) term in the ID control have been set to fixed values by intermediate tuning so as to satisfy the specifications in all operating states of the system. Of course, the control constants set in this manner cannot be the optimum values corresponding to the predetermined operating state, and thus cause a reduction in the responsiveness and stability of the throttle valve. [0005] Further, each control constant in such PID control depends on environmental fluctuations (for example, temperature,
The power supply voltage, etc.) and the control objects (DC motor, throttle valve, throttle opening sensor, etc.) are set so as to satisfy the specifications with respect to disturbances caused by manufacturing variations and aging. However, some of these variations and changes over time are unpredictable. If these unpredictable variations or changes over time occur, a throttle opening sensor value corresponding to the actual throttle opening based on the throttle opening command value of the throttle valve is preset as shown in FIG. There is a possibility that an overshoot phenomenon that fluctuates to the open side or the closed side beyond the fully open position on control or the fully closed position on control may occur. When such an overshoot phenomenon occurs, the physical full open position (full open stopper position) when the throttle valve is fully opened or fully closed.
Alternatively, the vehicle may collide with the fully closed position (fully closed stopper position), which may cause abnormal noise and damage to the throttle valve, the reduction gear train, and the like. Therefore, it is inevitable that an expensive material is used to suppress the above-mentioned variation and aging, a very strict tolerance design / manufacturing control is performed, and a cost increase is required by performing a 100% performance inspection at the time of shipment. Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a throttle control device for an internal combustion engine which can prevent an overshoot phenomenon at the time of driving a throttle valve in an electronic throttle system. A throttle control apparatus for an internal combustion engine according to the present invention controls a throttle valve opening by driving a DC motor in accordance with an amount of depression of an accelerator pedal. Throttle valve control means for controlling the throttle valve by PID control of a motor; and a slot for detecting the opening of the throttle valve
Throttle opening detecting means and the throttle opening detecting means
The detected throttle opening depends on the throttle valve control.
Judgment has been made that the full open position has been
Is a fully closed control in the throttle valve control means.
When it is determined that the position is less than the position, control constant changing means for changing the D term of the control constants of the PID control is provided. In the throttle control apparatus for an internal combustion engine according to the present invention , the DC motor is controlled by the PID by the throttle valve control means.
The throttle valve is controlled. And the slot
The throttle opening detected by the throttle opening detection means
Exceeding the control fully open position in the rotary valve control means
Or the throttle valve control means
When it is determined that the position is less than the fully closed position in the control, the D term of the control constant of the PID control is changed by the control constant changing means. For this reason, in controlling the opening and closing of the throttle valve,
The final convergence speed immediately before the fully open position or the fully closed position on control is suppressed. Hereinafter, the present invention will be described with reference to specific examples. FIG. 1 is a schematic diagram showing the overall configuration of a throttle control device for an internal combustion engine according to one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an internal combustion engine, and air is supplied to the internal combustion engine 1 through an intake passage 2. Reference numeral 3 denotes a throttle valve. The throttle valve 3 is provided in the middle of the intake passage 2. The throttle valve 3 is provided with a throttle opening sensor 4 for detecting a throttle opening. Reference numeral 5 denotes an accelerator pedal. The accelerator pedal 5 has an accelerator opening sensor 6 for detecting an accelerator opening.
Is provided. Reference numeral 10 denotes an ECU (Electronic Control Unit:
The ECU 10 receives a throttle opening signal TH from the throttle opening sensor 4 and an accelerator opening signal Ap from the accelerator pedal 5.
Reference numeral 12 denotes a DC motor as an actuator.
A current is supplied to the motor 12 from the ECU 10 side. Reference numeral 13 denotes a reduction gear train disposed between the DC motor 12 and the throttle valve 3, and reference numeral 14 denotes a return spring that 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 the accelerator opening sensor 6 corresponding to the amount of depression of the accelerator pedal 5 and a throttle opening signal from the 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.
The actual throttle 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 opening sensor 6 corresponding to the accelerator opening of the accelerator pedal 5
Of the motor drive circuit 1 by PID control by the PID control circuit 10b so that there is no deviation from the throttle opening command value θcmd calculated based on the accelerator opening signal Ap.
1, feedback control for the DC motor 12 is executed. 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 slope of the rise or fall 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 throttle opening command value θcmd and the actual throttle opening 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. Next, the processing procedure in the PID control of the throttle opening of the ECU 10 used in the throttle control apparatus for an internal combustion engine according to one embodiment of the present invention will be described with reference to the flowchart of FIG. First, in step S101, it is determined whether a time T1 (for example, 4 ms; the shorter the better, the better) has elapsed from the previous determination. Step S101
When this determination condition is not satisfied, the present routine is terminated. On the other hand, when the determination condition of step S101 is satisfied, the process proceeds to step S102, and a value θn obtained by A / D conversion of the throttle opening TH of the throttle valve 3 at time n is obtained. Next, the routine proceeds to step S103, where the throttle opening TH of the throttle valve 3 is set to A / D.
The valve angular velocity Δθn of the throttle valve 3 is obtained from the difference between the converted current value θn and the previous value θn-1. Next, the process proceeds to step S104, in which the accelerator opening Ap of the accelerator pedal 5 and the C / C (Crui) that enable the vehicle to run at a constant speed without operating the accelerator pedal.
se Control (cruise control), ISC (Idle Speed C) that stabilizes the engine speed when the internal combustion engine is idle
ontrol: target opening θM obtained from idle speed control) and throttle opening T of throttle valve 3
A deviation Err from the current value θn obtained by A / D conversion of H is obtained. Next, the process proceeds to step S105, and step S10
The error Err obtained in step 4 is multiplied by the P-term gain Kp to obtain P
The term output value Tmp is obtained. Next, the process proceeds to step S106, and the valve angular velocity Δ obtained in step S103.
θn is multiplied by a D-term gain Td to obtain a D-term output value Tmd. Next, the routine proceeds to step S107, where the deviation Err obtained in step S104 is added to the previous total deviation In-1, and the current total deviation In is obtained. Next, the process proceeds to step S108, and it is determined whether the total deviation In obtained in step S107 exceeds the upper limit Imax. When the determination condition in step S108 is satisfied, the process proceeds to step S109, and the total deviation In is set to Imax as the upper limit guard. On the other hand, if the determination condition in step S108 is not satisfied, the process proceeds to step S110, and it is determined whether the total deviation In obtained in step S107 is less than the lower limit value -Imax. When the determination condition of step S110 is satisfied,
The process moves to step S111, and the total deviation In is set to -Imax as the lower limit guard. If the condition of step S110 is not satisfied, step S109 or step S11
After the processing of step 1, the flow shifts to step S112, where the total deviation I
n is multiplied by an I-term gain Ti to obtain an I-term output value Tmi. Next, the process proceeds to step S113, and step S1
The P-term output value Tmp obtained in step 05, the D-term output value Tmd obtained in step S106, and the I-term output value Tmi obtained in step S112 are added to obtain a final output value Tm in PID control. Next, the routine proceeds to step S114, where Duty for PWM control of the DC motor 12 is obtained by multiplying the final output value Tm obtained in step S113 by the conversion coefficient Ka. Next, a processing procedure for suppressing the overshoot of the throttle opening of the ECU 10 used in the throttle control device for an internal combustion engine according to one embodiment of the present invention will be described with reference to the flowchart of FIG. This will be described with reference to a chart. In step S201, T1 is determined from the previous determination.
It is determined whether the time (for example, 4 ms) has elapsed. When the determination condition of step S201 is not satisfied, the present routine ends. On the other hand, when the determination condition of step S201 is satisfied, the process proceeds to step S202, and a value θn obtained by A / D conversion of the throttle opening TH of the throttle valve 3 at time n is obtained. Next, the process proceeds to step S203, where the throttle opening TH of the throttle valve 3 is subjected to A / D conversion between the current value θn and the previous value θn−
From the difference from 1, the valve angular velocity Δθ of the throttle valve 3
n is required. Next, the process proceeds to step S204, in which the absolute value of the valve angular velocity Δθn is determined by a driving determination constant Kb (for example,
0.4 ° / 4 ms). If the determination condition in step S204 is not satisfied, it is determined that the throttle valve 3 is stopped, and this routine ends without performing an overshoot check. On the other hand, when the determination condition of step S204 is satisfied, it is determined that the throttle valve 3 is being driven, and the process shifts to step S205 to set the throttle opening TH of the throttle valve 3 to A / D.
It is determined whether or not the converted current value θn exceeds the fully open position for control (see FIG. 6). When the determination condition of step S205 is not satisfied, the process proceeds to step S206,
It is determined whether the current value θn obtained by A / D conversion of the throttle opening TH of the throttle valve 3 is smaller than the fully closed position (see FIG. 6) under control. If the determination condition in step S206 is not satisfied, it is determined that there is no overshoot exceeding the fully open position and the fully closed position in the control, and this routine ends. On the other hand, when the determination condition of step S205 is satisfied, it is determined that an overshoot on the open side exceeding the fully open position on the control has occurred, and step S207 is performed.
And the D term gain Td, which is the control constant of the D term, is set to 0.
1 is added, and this routine ends. Further, when the determination condition of step S206 is satisfied, it is determined that the overshoot on the closing side that is less than the fully closed position on the control has occurred, and the process proceeds to step S207, where D term, which is the control constant of D term, is obtained. 0.1 is added to the gain Td, and this routine ends. As described above, when an overshoot phenomenon occurs in which the throttle opening fluctuates to the open side or the closed side beyond the fully open position in control or the fully closed position in control during the operation of the throttle valve 3, The D-term gain Td, which is the control constant of the D-term, is changed. Thereby, the final convergence speed at the time of driving the throttle valve 3 is suppressed, and when the throttle valve 3 is fully opened or fully closed, the physical fully open position (fully open stopper position) or the fully closed position (fully closed stopper position). ) Is prevented beforehand. As described above, the throttle control device for an internal combustion engine according to the present embodiment has a D
In the control of the opening degree of the throttle valve 3 by driving the C motor 12, throttle valve control means achieved by the ECU 10 which controls the throttle valve 3 by PID control of the DC motor 12, and the opening of the throttle valve 3
Slot as throttle opening detection means for detecting the degree
Detected by the throttle opening sensor 4 and the throttle opening sensor 4
The throttle opening TH is calculated as the target opening θ M
Of the control by the throttle valve control means
Judge that the position has been exceeded or throttle valve control
When it is determined that the fully closed below a position on the control in means is for and a control constant changing unit achieved by ECU10 to change the D-term gain Td among the control constant of the PID control. Therefore, the DC motor 12 is PID-controlled by the throttle valve control means, the throttle valve 3 is controlled, and the throttle valve detected by the throttle opening detection means is controlled.
Throttle valve with target opening TH as target opening TH
Judgment that the control unit has exceeded the fully open position in control, or
Or control fully closed position in throttle valve control means
When it is determined that the value is less than the
Among the control constants of the D control, the D term gain Td is changed.
Therefore, the target opening θM for opening and closing the throttle valve 3
The final convergence speed immediately before is suppressed, and the throttle opening is prevented from being driven beyond the target opening θM. [0033] As has been described in the foregoing, according to the throttle control apparatus for an internal combustion engine of the present invention, DC motor throttle valve control means throttle valve is PID control is controlled, in the throttle opening detection means Slot detected
The throttle opening is controlled by the throttle valve control means.
Is determined to have exceeded the fully open position of
When it is determined that the position is less than the fully closed position in the control by the control means, the control constant changing means changes the D term of the control constant of the PID control. As a result, the final convergence speed immediately before the control fully open position or the control fully closed position in opening and closing the throttle valve is suppressed, and the throttle opening is controlled.
Driving beyond the upper fully open position or the control fully closed position is prevented. Thus, Ri Do the throttle opening degree is suitable <br/> Yichun set throttle control that does not exceed the fully closed position <br/> on fully open position or control of the control is executable, open
The throttle valve itself or its drive on the side or closed side
Eliminates concerns about damage to the system and tight tolerances
It is not necessary to carry out total management
Can achieve a significant cost reduction
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an overall configuration of a throttle control device for an internal combustion engine according to one 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 a flowchart showing a processing procedure in PID control of a throttle opening of an ECU used 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 suppressing an overshoot of a throttle opening 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 conventional throttle control device for an internal combustion engine. [Description of Signs] 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

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazunori Nonoyama 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. Field (Int.Cl. ⁷ , DB name) F02D 9/02 351 F02D 11/10

Claims (1)

(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 according to an amount of depression of an accelerator pedal. Throttle valve control means for controlling the throttle valve by differential control; throttle opening for detecting the opening of the throttle valve
Detecting means and a slot detected by the throttle opening detecting means
The throttle opening is controlled by the throttle valve control means.
Is determined to have exceeded the fully open position
Control constant changing means for changing a differential term among the control constants of the proportional / integral / differential control when it is determined that the position is less than the fully closed position in the control by the lube control means. Throttle control device.