JPS61210237A - Accel control device for internal-combustion engine for vehicle - Google Patents

Abstract

PURPOSE:To prevent the occurrence of hunting when a shift position is at a low speed stage and improve responsiveness when at a high speed stage, by a method wherein the gain of a fuel feed control amount is varied depending upon the shift position of a transmission connected to an engine. CONSTITUTION:A potentiometer 4 is provided for detecting a control amount of an accel pedal 1. A servo motor 8, serving as a fuel feed amount control means, is mounted to the one end of a rotary shaft 7a of a throttle valve 7 mounted to a throttle chamber 6 of an engine, and a potentiometer 9, detecting the opening of a throttle valve 7, is attached to the servo motor 8. Further, a switch 12 is provided for detecting the shift position of a transmission connected to the output shaft of an engine. Detecting signals from detectors 4, 9, and 12 are respectively inputted to a controller 5 to compute and process a control amount of the opening of the throttle valve 7. This causes computed and processed amplification analogue signal to be outputted from the controller 5 to the servo motor 8 which is rotated and driven.

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 controlled according to the polarity and magnitude of the deviation. A servo motor or the like drives the throttle valve to open or close according to the control amount to control the target opening.

<Problems to be Solved by the Invention> However, in such conventional electronically controlled accelerator control devices, when setting the control amount of the throttle valve opening, the control gain is fixed to a preset value. This caused problems as described below.

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. 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 engine's perspective, so the throttle valve opening is Even if hunting occurs, the engine speed can absorb torque fluctuations and change smoothly, but 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 throttle valve opening may be followed by hunting in the engine rotational speed.

If the control gain is reduced in order to solve this problem, the response when the shift position is set to the high speed gear will be significantly reduced, 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 Problems> For this reason, the present invention provides 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 fuel supply amount detection means B that detects the supply amount of a fuel supply device provided in an on-board internal combustion engine; a fuel supply control amount setting means C that sets a control amount of the fuel supply amount based on at least these detected values; A shift position detection means for detecting a shift position of a transmission connected to an engine in a vehicle accelerator control device comprising a fuel supply amount control means for variably controlling the fuel supply amount based on a fuel supply control amount signal. E, and a control gain setting means F that variably sets the control gain of the fuel supply device according to the detected value of the shift position.

With this configuration, the control gain can be appropriately set according to the shift position of the transmission, and hunting in the engine rotational speed when the shift position is set to a low gear can be suppressed, as well as , good responsiveness can be maintained when the shift position is set to the high speed gear.

<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 l, 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 attached to a throttle chamber 6 of the engine.
The servo motor 8 is driven by the output from the controller 5. Further, a valve potentiometer 9 for detecting the opening degree of a throttle valve is integrally attached to the servo motor 8 as a means for detecting the amount of fuel supplied, and a signal from the valve potentiometer 9 is inputted to the controller 5.

A return spring 11 is attached between a lever 10 fixed to the other end of the rotating shaft 7a and the wall of the engine body 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 analog signals from the pedal potentiometer 4 and the valve potentiometer 9 into digital signals.
/Accelerator pedal stroke amount i from D converter 51
In addition to inputting the signal and the throttle valve opening θ signal, the shift position Sf signal from the shift position switch 12 is also 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 amplified by the servo driver 54, and the amplified analog signal is output to the servo motor 8 to drive the servo motor 8 to a predetermined position. It is designed to drive angle rotation.

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 Sl, the stroke amount l of the accelerator pedal 1 is read based on the signal from the pedal potentiometer 4.

In S2, the target value θ of the opening degree of the throttle valve 7 corresponding to the stroke Mβ is calculated from the map a stored in the ROM of the microcomputer 52;
Search for.

In S3, the detected value θ7 of the opening degree of the throttle valve 7 is read based on the signal from the valve potentiometer 9.

In S4, the deviation e=θ between the target value θ and the detected value θa
, -θ7 is calculated.

In S5, it is determined whether the deviation e is equal to O within the error range. If YES, the opening degree of the throttle valve 7 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 θ7 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 Sf of the transmission detected by the shift position switch 12 is read.

In S8, the values of two control gains Kp and Kv used when determining the throttle valve opening control amount by the fuel supply control amount setting means in S9, which will be described later, are expressed as a function of the shift position S in a map stored in the memory. Search and set.

Here, the map of Kv and S
The search function No. 8 constitutes the 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.

T = K, e - KvV = (1) S10
Now, the signal corresponding to the control amount T obtained by SIO is converted to D/A.
Output to 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, which 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 θ3.

Next, the effect of such control will be explained.

The above equation (11) is an equation corresponding to proportional + speed feedback control (hereinafter referred to as PV!116).

In other words, the target value θ is now reached by operating the accelerator from a steady state.
1 changes, the deviation e increases and the output of the servo motor 8 increases, so the throttle valve opening operates to follow the target value θ1. However, if the speed V is too large, overshoot or undershoot will become large after reaching the target value of 6, causing hunting, etc., so this should be prevented (reducing the control amount as the speed V increases). In other words, the KvVO term has a damping effect.

However, if the control gain and Kv are constant values as in the prior art, a problem will occur due to the difference in shift position, which will be described later.

That is, for example, when the control gains are set to KP and Kv to intermediate values that are matched when the shift position is set to middle gear, if the accelerator pedal is suddenly depressed or released and the deviation e increases, The e term becomes large, while the K and V terms become small (both in absolute value).

Therefore, the throttle valve opening degree control amount T becomes large, and hunting occurs in the throttle valve opening degree θ 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 high speed, 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 9. This cannot be absorbed, and the rotational speed N also follows the hunting of the throttle valve opening θ.

To avoid such hunting, the value of K is small,
The value of Kv can be increased to prevent the control amount from becoming excessive, but if you do this, the shift position will be set to the high speed gear, and in situations where rotational inertia is large, the rotational speed will decrease in response to accelerator operation. This results in a decrease in responsiveness.

Therefore, in this embodiment, Kp searched in S8,
The value of Kv is set as shown in FIGS. 4 and 5, respectively, depending on the shift position.

That is, K is set to be larger as the shift position becomes a higher speed gear, and conversely, Kv 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, e will be small and K and V will be large in equation (1) for the same accelerator operation amount, so the throttle valve opening will be controlled. The amount is set small, so that even when the accelerator operation amount is large, the throttle valve opening θ changes smoothly without hunting as shown in FIG. As shown in a in the figure, smooth tracking and stable characteristics are obtained.

Also, when the shift position is set to high speed,
Compared to the case where the throttle valve is set to the low speed gear, e is set to be large and Kvv is set to be small in equation (1), so the throttle valve opening control amount T is set to be large.

As a result, the throttle valve opening θ quickly follows the accelerator operation, and accordingly, the rotational speed N can also follow suitably. In addition, as shown in Figure 6, the throttle valve opening θ causes hunting after reaching the target value θ, but since the rotational inertia is large, torque fluctuations are absorbed, and the value becomes b in Figure 7. As shown, the rotational speed N changes smoothly without any hunting.

Although this embodiment has been described with respect to a device that performs pv control, it goes without saying that the present invention can also be applied to a device in which control based on the throttle valve opening/closing speed is omitted and control is performed only using the deviation e.

In addition, in this embodiment, an engine having a throttle valve was described as a fuel supply device, but signals outside the throttle valve plate, such as intake air amount, fuel injection amount, and a fuel injection pump in a diesel engine or the like without a throttle valve, can also be used. It is also possible to detect a signal from a control lever or the like, use this as the fuel supply amount, and set the control amount of the fuel supply amount.

<Effects of the Invention> As explained above, according to the present invention, since the control gain of the fuel supply control amount is variably controlled according to the shift position of the transmission, hunting of the engine rotational speed can be prevented, and The effect of ensuring good responsiveness can also be obtained.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration and functions of the present invention, Figure 2 is a block diagram showing the configuration and functions of the present invention.
The figure shows the configuration of an embodiment of the present invention, and FIG. 3 is a flowchart showing the throttle valve opening control routine of the embodiment.
Fig. 4 is a graph showing the characteristics of the control gain KP used in the above embodiment, Fig. 5 is a graph showing the characteristics of the control gain Kv used in the above embodiment, and Fig. 6 is a graph showing the shift position of the above embodiment. Fig. 7 is a graph showing the hourly characteristic of the engine rotation speed corresponding to the throttle valve opening change in Fig. 6, and Fig. 8 is a graph showing the hourly characteristic of the throttle valve opening with
FIG. 9 is a diagram showing an example of the hourly characteristic of the throttle valve opening in the v control, and FIG. 9 is a diagram showing the hourly characteristic of the engine rotation speed 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 Patent applicant Nissan Motor Co., Ltd. Representative Patent attorney Fujio SasashimaFigure 1Figure 3Figure 4Figure 5 Shift position Fig. 6 Fig. 7 Time Fig. 8 Fig. 9 Time t

Claims (1)

[Claims] an accelerator operation amount detection means for detecting an operation amount of an accelerator operation means of a vehicle operated by a driver; a fuel supply amount detection means for detecting a supply amount of a fuel supply device provided in a vehicle-mounted internal combustion engine; A fuel supply control amount setting means for setting a control amount of the fuel supply amount based on at least these detected values, and a fuel supply amount control means for variably controlling the fuel supply amount based on the fuel supply control amount signal. In a vehicle accelerator control device, a shift position detection means detects a shift position of a transmission connected to an engine; a control gain setting means variably sets a gain of a fuel supply control amount according to a detected value of the shift position; An accelerator control device for a vehicle internal combustion engine, characterized in that it is provided with: