JPH0421058B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an accelerator control device for a vehicle internal combustion engine.

<Prior Art> Conventional accelerator control devices for internal combustion engines for vehicles, as shown in Japanese Patent Application Laid-Open No. 59-120744, have conventional accelerator operations performed by a throttle valve installed in the intake system of the engine. Instead of a mechanical transmission, there is one that electronically controls the throttle valve opening depending on the amount of depression of the accelerator pedal.

Specifically, the deviation between the target value of the throttle valve opening according to the amount of depression of the accelerator pedal and the detected value of the throttle valve opening is determined, and the throttle valve opening is determined according to the polarity and magnitude of the deviation. A control amount is set, and the throttle valve is driven to open and close by a servo motor or the like in accordance with the control amount to control the target opening.

<Problems to be Solved by the Invention> However, in such a conventional electronically controlled accelerator control device, when setting the control amount of the throttle valve opening, the control gain is set to a preset value. Because it is fixed, problems such as those described below have occurred.

That is, for example, in a case where the control amount of the throttle valve opening is set based only on the deviation between the target value and the detected value of the throttle valve opening, if the control gain is large, the target value is not reached. Even after that, overshoot and undershoot occur, resulting in hunting.

In this case, when the shift position of the transmission connected to the engine is set to 4th gear, etc., the load is large and the rotational inertia is large from the perspective of the engine, so the throttle valve opening is Even if hunting occurs, the engine speed can absorb torque fluctuations and change smoothly. However, when the shift position is set to a low gear such as 1st gear, the load on the engine is small and the rotational inertia is small. Therefore, hunting in the engine rotational speed may occur as a result of hunting in the opening degree of the throttle valve.

To solve this problem, if we reduce the control gain,
This time, when the shift position is set to a high speed gear, the responsiveness decreases significantly, resulting in a loss of acceleration performance.

The present invention has been made in view of these conventional problems, and provides a vehicle for use in which the occurrence of hunting can be effectively prevented while maintaining good responsiveness of the engine rotation speed to accelerator operation. An object of the present invention is to provide an accelerator control device for an internal combustion engine.

<Means for Solving the Problems> For this reason, the present invention includes an accelerator operation amount detection means A for detecting the operation amount of an accelerator operation means of a vehicle operated by a driver, as shown in FIG. ,
A throttle valve opening detection means B that detects the opening of a throttle valve installed in the intake system of an internal combustion engine installed in a vehicle, and a throttle valve opening that sets a control amount of the throttle valve opening based on these detected values. A vehicle accelerator operating device comprising a control amount setting means C and a throttle valve drive means D that opens and closes the throttle valve based on a throttle valve opening control amount signal, which is adapted to shift a transmission connected to an engine. The shift position detection means _E detects the position, and the deviation e (=θ _a −θ ), the proportional control gain setting means F sets the proportional control gain K _P to a larger value as the detected shift position becomes higher. ), the speed control gain setting means G sets the speed control gain _KV smaller as the detected shift position becomes a higher speed gear. T
The configuration is such that T=K _P e - K _V V.

<Operation> In this configuration, the throttle valve opening control amount is set to a value set from the deviation between the target value and the detected value of the throttle valve opening, and the control amount is set to decrease as the throttle valve opening/closing speed increases. By performing proportional-speed feedback control, hunting in the engine rotational speed due to an increase in the opening/closing speed of the throttle valve is suppressed.

In a device that performs such proportional speed feedback control, the lower the shift position of the transmission, the smaller the rotational inertia of the engine, and the tendency for hunting to occur.However, the lower the gear, the smaller the proportional control gain K _P becomes. However, by setting the speed control gain K _V large, hunting can be suppressed at low speeds, and the proportional control gain K _P can be set large at high speeds.
By setting the speed control gain K to a large value and the speed control gain _K to a small value, good responsiveness can be maintained.

<Example> Examples of the present invention will be described below.

FIG. 2 shows the overall configuration of the first embodiment. In the figure, an accelerator pedal 1 serving as an accelerator operating means is pivotally supported by a floor panel 2, and is biased by a return spring 3 in a direction to return it to an idle position. As a means for detecting the stroke amount (accelerator operation amount) of the accelerator pedal 1, a pedal potentiometer 4 is attached to the floor panel 2.
A detection signal from the controller 5 is input to the controller 5.

Further, a servo motor 8 as a fuel supply amount control means is attached to one end of a rotating shaft 7a of a throttle valve 7 as a fuel supply device mounted on a throttle chamber 6 of the engine, and the servo motor 8 is operated by the controller. It is driven by the output from 5. Further, a valve potentiometer 9 for detecting the throttle valve opening is integrally attached to the servo motor 8 as a fuel supply amount detection means, and a signal from the valve potentiometer 9 is inputted to the controller 5. .

, a lever 10 fixed to the other end of the rotating shaft 7a
A return spring 11 is attached between the throttle valve 7 and the engine body wall to bias the throttle valve 7 in the fully closing direction.

Furthermore, a shift position switch 12 composed of a limit switch or the like is provided as means for detecting the shift position of the transmission connected to the output shaft of the engine, and this signal is also input to the controller 5.

The controller 5 is configured to include each processing section as follows. That is, the A/D converter 51 converts the analog signals from the pedal potentiometer 4 and the valve potentiometer 9 into digital signals, and the microcomputer 52 converts the stroke amount of the accelerator pedal from the A/D converter 51. In addition to inputting the l signal and the throttle valve opening θ signal, the shift position S _f signal from the shift position switch 12 is input, and based on these signals, the control amount of the throttle valve 7 opening is calculated as described below. . The digital control signal from the microcomputer 52 is converted into an analog control signal by the D/A converter 53, and then the servo driver 54
The amplified analog signal is output to the servo motor 8 to rotate the servo motor 8 by a predetermined angle.

Next, a control routine by the microcomputer 52 of this embodiment will be explained with reference to the flowchart shown in FIG. This flow is activated at regular time intervals by an operating system (not shown).

At S1, the stroke amount l of the accelerator pedal 1 is determined based on the signal from the pedal potentiometer 4.
Load.

In S2, the target value _{θ a} of the opening degree of the throttle valve 7 corresponding to the stroke amount l is retrieved from the map a stored in the ROM of the microcomputer 52.

In S3, based on the signal from the valve potentiometer 9, the detected value θ _T of the opening degree of the throttle valve 7 is read.

In S4, the deviation e between the target value θ _a and the detected value θ _T is determined.
= θ _a −θ _T is calculated.

In S5, it is determined whether the deviation e is equal to 0 within the error range. If YES, the throttle valve 7 opening degree is maintained at the current level and the process ends; if NO, the process proceeds to S6.

In S6, the opening/closing speed V of the throttle valve 7 is calculated from the amount of change in θ _T per unit time (for example, the difference from the previous read value). Here, the value of V takes a positive or negative value corresponding to the opening/closing direction of the throttle valve 7.

In S7, the shift position S _f of the transmission detected by the shift position switch 12 is read.

In S8, the proportional control gain K _P and the speed control gain are used when determining the throttle valve opening control amount by the fuel supply control amount setting means in S9, which will be described later.
The value of K _V is set by searching a map stored in memory as a function of the shift position S _f .

Here, the map of K _p and K _v stored in the memory and the search function of S8 constitute proportional control gain setting means and speed control gain setting means.

In S9, the control amount T of the opening degree of the throttle valve 7 is set based on the following equation. The function of step 9 constitutes a throttle valve opening control amount setting means.

T=K _p e - K _v V (1) In S10, a signal corresponding to the control amount T obtained in S9 is output to the D/A converter 53.

As a result, the analog control signal converted by the D/A converter 53 is amplified by the servo driver 54 and then output to the servo motor 8.
The servo motor 8 drives the throttle valve 7 to open and close by a predetermined amount.

By continuously performing such control, the throttle valve 7 is controlled to an opening equal to the target value θ _a .

Next, the effect of such control will be explained.

The above equation (1) is an equation corresponding to proportional + speed feedback control (hereinafter referred to as PV control).

That is, if the target value _θ a changes by operating the accelerator from a steady state, the deviation e will increase,
Since the output of the servo motor 8 increases, the throttle valve opening operates to follow the target value θ _a . However, if the speed V is too large, the overshoot or undershoot will increase after reaching the target value θ _a , causing hunting, etc. To prevent this, the control amount will be adjusted according to the increase in the speed V. I am trying to reduce this. In other words, the term K _V V has a damping effect.

However, if the control gains K _P and K _V are constant values as in the prior art, a problem described below will occur due to the difference in shift position.

That is, for example, when the control gains are set to intermediate values that are matched when the shift position is set to middle gear, K _P and K _V are set to intermediate values that are matched when the shift position is set to middle _gear . The e term becomes large, while the K _V V term becomes small (both in absolute value).

For this reason, the throttle valve opening control amount T becomes large,
The throttle valve opening degree θ causes hunting as shown in FIG.

In this way, even if the throttle valve opening is hunting, the rotational inertia of the engine is large when the shift position is set to the high speed gear, so the throttle valve opening θ will change as shown in Figure 9a. Stable rotational speed characteristics can be obtained by absorbing torque fluctuations due to hunting, but since the rotational inertia of the engine is small when the shift position is set to a low gear, torque fluctuations are absorbed as shown in Figure 9b. This cannot be absorbed, and the rotational speed N also follows the hunting of the throttle valve opening θ.

In order to avoid such hunting, the value of K _p should be made small and the value of K _v should be made large to prevent the control amount from becoming excessive.
This time, the shift position is set to a high speed gear, and in a situation where the rotational inertia is large, the responsiveness of the rotational speed to the accelerator operation is reduced.

Therefore, in this embodiment, the values of K _p and K _v retrieved in S8 are set as shown in FIGS. 4 and 5, respectively, depending on the shift position.

That is, K _P is set to be larger as the shift position becomes a higher speed gear, and conversely, K _V is set to be smaller as the shift position becomes a higher speed gear.

In this way, when the shift position is set to a low gear, K _p e in equation (1) will be small and K _v will be large for the same accelerator operation amount, so the throttle valve opening control amount will be is set small, so that even when the amount of accelerator operation is large, the sixth
As shown in FIG. 7a, the throttle valve opening θ changes smoothly without hunting, and accordingly, the rotational speed N follows smoothly as shown in FIG. 7a, resulting in stable characteristics.

Furthermore, when the shift position is set to the high speed gear, K _p e in equation (1) is set larger and K _v V is set smaller than when the shift position is set to the low speed gear, so the throttle valve opening is The degree control amount T is set to be large.

As a result, the throttle valve opening θ quickly follows the accelerator operation, and the rotational speed N can also follow suitably. Also, throttle valve opening θ
As shown in Figure 6b, hunting occurs after the target value θ _a is reached, and since the rotational inertia is large, torque fluctuations are absorbed, and the rotational speed decreases as shown in Figure 7b. N changes smoothly without causing hunting.

<Effects of the Invention> As explained above, according to the present invention, variable control is performed such that the proportional control gain of the throttle valve opening control amount becomes larger and the speed control gain becomes smaller as the shift position of the transmission becomes a higher gear. Because it is configured to
This has the effect of preventing engine rotational speed hunting and ensuring good responsiveness.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration and functions of the present invention, FIG. 2 is a diagram showing the configuration of an embodiment of the present invention,
FIG. 3 is a flowchart showing the throttle valve opening control routine of the above embodiment, FIG. 4 is a graph showing the characteristics of the control gain K _P used in the above embodiment, and FIG.
The figure is a graph showing the characteristics of the control gain _KV used in the above embodiment, Figure 6 is a graph showing the throttle valve opening versus time characteristic using the shift position as a parameter in the above embodiment, and Figure 7 is a graph showing the characteristic of the control gain KV used in the above embodiment. Graph showing the engine rotation speed vs. time characteristic corresponding to the throttle valve opening change in Figure 6, No. 8
The figure is a diagram showing an example of the throttle valve opening-time characteristic in conventional PV control, and FIG. 9 is a diagram showing the engine rotation speed-time characteristic using the shift position as a parameter in the conventional example. 1... Accelerator pedal, 4... Pedal potentiometer, 5... Control unit, 7...
Throttle valve, 8... Servo motor, 9... Valve potentiometer, 12... Shift position switch.

Claims (1)

[Claims] 1 Accelerator operation amount detection means that detects the operation amount of the accelerator operation means of the vehicle operated by the driver, and throttle valve opening that detects the opening degree of the throttle valve installed in the intake system of the internal combustion engine installed in the vehicle. and a proportional control gain for the deviation e (=θ _a - θ) between the target throttle valve opening θ _a set based on the detected accelerator operation amount and the detected throttle valve opening θ.
K _P , when the speed control gain for the opening/closing speed V (opening direction is positive) determined based on the throttle valve opening θ is K _V , the throttle valve opening control amount T is T
A vehicle accelerator comprising a throttle valve opening control amount setting means for setting the throttle valve opening control amount as =K _P e−K _V V, and a throttle valve driving means for driving the throttle valve to open and close based on the throttle valve opening control amount signal. In the operating device, a shift position detection means for detecting a shift position of a transmission connected to the engine; a proportional control gain setting means for setting the proportional control gain K _P to be larger as the detected shift position becomes a higher gear; An accelerator control device for an internal combustion engine for a vehicle, comprising: speed control gain setting means for setting the speed control gain _KV to be smaller as the detected shift position becomes a higher speed gear.