JPS618442A - Abnormality diagnosis device in accelerator control device in vehicle internal combustion engine - Google Patents

Abstract

PURPOSE:To enhance the safety of a vehicle, by determining an abnormality in a pedal displacement detecting means when the displacement of an accelerator pedal does not indicates the zero position upon releasing of the accelerator pedal at which a brake pedal is depressed. CONSTITUTION:In an accelerator control device for a vehicle internal combustion engine, a control signal generating means B issues a control signal for the open degree of a throttle valve 9 in accordance with the output of an accelerator pedal displacement detecting means A for detecting the displacement of an accelerator pedal, and a throttle drive means C is controlled in accordance with the control signal. In this case, there is provided a brake operation detecting means D for detecting depression of a brake peda and an abnormality determining means E for determining whether the pedal displacement detecting means A is abnormal or not. This abnormality determining means E is arranged such that the displacement of the accelerator pedal is compared with a reference value upon depression of the brake pedal (accelerator pedal is released) to determine whether the pedal displacement detecting means A is abnormal or not.

Description

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

<Prior art> As an electronic accelerator control device for a vehicle internal combustion engine,
For example, there is a method as shown in Japanese Patent Application Laid-Open No. 59-58131.

In this device, the amount of displacement of the accelerator pedal is normally detected electrically, and an actuator is used to drive the throttle valve to open and close so that the opening degree of the throttle valve corresponds to the amount of displacement, and when the clutch is disengaged, the accelerator pedal The opening of the throttle valve is controlled so that the engine speed matches the vehicle speed regardless of the amount of displacement of the clutch, thereby preventing clutch slippage.

<Problems to be Solved by the Invention> By the way, in such conventional electronic accelerator control devices, the means for detecting the accelerator pedal position (potentiometer, etc.) may deteriorate due to aging or may malfunction. If this occurs and a signal that does not correspond to the actual accelerator pedal position is output, problems such as acceleration against the driver's will or the engine speed being held at a high speed may occur.

The present invention has been made in view of such conventional problems, and provides an abnormality diagnosis device for an accelerator control device for a vehicle internal combustion engine, which is capable of detecting an abnormality in an accelerator pedal position detection means. The purpose is to

Means for Solving the Problems> Therefore, as shown in FIG. A control signal generating means B that generates a control signal for the throttle valve opening based on the detected accelerator pedal displacement amount, and a throttle valve driving means that drives the throttle valve to open and close so that the valve opening corresponds to the control signal. In the accelerator control device for a vehicle internal combustion engine, the accelerator control device includes: a brake operation detection means for detecting that the brake pedal of the vehicle is depressed; and a pedal displacement amount detection means for detecting depression of the brake pedal. Abnormality determining means E for determining whether or not there is an abnormality in pedal displacement amount detecting means A by comparing the amount of displacement of the accelerator pedal with a reference value.

<Operation> With this configuration, when the displacement amount of the accelerator pedal does not detect a zero position when the accelerator pedal is released by depressing the brake pedal, it can be determined that the pedal displacement amount detection means is abnormal.

<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 operated by a driver is pivotally supported by a floor panel 2, and is urged by a return spring 3 in a direction to return it to an idle position. A pedal potentiometer 4 is attached to the floor panel 2 as a means for detecting the displacement amount (stroke amount) Il of the accelerator pedal 1, and a detection signal from the pedal potentiometer 4 is input to the A/D converter 51 of the controller 5. Ru.

Further, a servo motor 8 as a throttle valve driving means is attached to one end of a rotating shaft 7a of a throttle valve 7 attached to a throttle chamber 6 of the engine, and the servo motor 8 is driven by the output from the controller 5. . A valve potentiometer 9 as throttle valve opening detection means is integrally attached to the servo motor 8 , and a signal from the valve potentiometer 9 is input to an A/D converter 51 of the controller 5 .

A return spring is attached between the 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.

Also, a brake pedal 12 located on the side of the accelerator pedal 1 and pivotally supported by the floor panel 2, and a brake pedal 12 that is pivotally supported by the floor panel 2
When the brake pedal 12 is pressed between the wall and the
A brake detection switch 13 is provided as a brake operation detection means that turns OFF when the brake is released. A signal from the brake detection switch 13 is input to the microcomputer 52 of the controller 5.

14 is a return spring.

The controller 5 is configured to include each processing section as follows. That is, the A/D converter 51 converts analog signals from the pedal potentiometer 4 and valve potentiometer 9 into digital signals. The microcomputer 52 inputs the signal from the A/D converter 51, processes the control amount of the opening of the throttle valve 7 as described later, and generates a control signal, and also outputs the signal from the brake detection switch 13. The presence or absence of an abnormality in the pedal potentiometer 4 is determined by inputting the signal. That is, it has both the functions of a control signal generating means and an abnormality determining means. 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 signal is output to the servo motor 8 to rotate the servo motor 8 by a predetermined angle. It is designed to be driven.

Next, the throttle valve opening control and abnormality diagnosis 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 displacement amount β of the accelerator pedal 1 is read based on the signal from the pedal potentiometer 4.

In S2, the data of the displacement amount β read in Sl is replaced with the previous data, and the previous data is replaced with the data from the time before the previous time, and so on. save data (n
If the startup cycle of the microcomputer is 5m5ec, for example, 2
(approximately 00).

In S3, map a stored in the ROM of the microcomputer 52
(See Fig. 4) to determine the target value θ of the opening degree of the throttle valve 7 corresponding to the displacement l. Search for.

In S4, the detected value θ of the opening degree of the throttle valve 7 is read based on the signal from the valve potentiometer 9.

In S5, a fail flag that issues an abnormality instruction (described later) is set to “
It is checked whether or not it is set to 1'', and if the cent is not set, the process advances to S6.

In S6, it is determined whether or not the brake pedal 12 is depressed based on the signal from the brake detection switch 13. If the brake pedal 12 is not depressed, the process proceeds to S7.

In S7, the target value θ. The deviation ε (−
〇. −〇) is calculated.

In S8, the absolute value of the deviation ε calculated in S7 is the predetermined value 60.
A predetermined value ε is determined.

If the control amount Δθ of the opening of the throttle valve 7 is set to 0 in S9, the control amount Δθ is set to a predetermined value ε. In the above cases, proceed to SIO.

In the SIO, the control amount Δθ of the opening degree of the throttle valve 7 with respect to the deviation ε is retrieved from the map b stored in the ROM of the microcomputer 52.

Sll outputs a control signal corresponding to the control amount Δθ of the opening degree of the throttle valve 7 to the D/A converter 53. This allows D/A
The analog control signal converted by the converter 53 is amplified by the servo driver 54 and output to the servo motor 8, and the servo motor 8 is rotated by a predetermined angle to open and close the throttle valve 7, thereby achieving the target value θ. The opening is controlled to match the opening.

On the other hand, if it is determined in S6 that the brake pedal 12 is depressed, the process advances to S12 and it is determined whether the current displacement amount of the accelerator pedal 1 "t-1" exceeds a predetermined value close to zero! However, in the following cases, it is determined that the pedal potentiometer 9 is normal, and the fail flag is reset to 0 in S13, and then the process proceeds to 37 to S11 to perform normal throttle valve opening control.

In addition, if it is determined in S12 that β,=,>X, the process proceeds to S14 and compares the current displacement amount nt=, with the past n-1 data stored in S2, and both The absolute value of the difference 1β+At=+l is 0 for all i=2 to n
It is determined whether the value is smaller than a predetermined value Δl close to . If this determination is YES, the displacement amount l of the accelerator pedal
is kept constant at a predetermined value greater than the value corresponding to the zero position, so the pedal potentiometer 9
It is determined that there is an abnormality. Set the fail flag in S15 “
1” and then set the target value θ of the throttle valve opening in S16.

θ. -0 and then proceeds to 87 where the throttle valve 7 is controlled to be fully closed.

Therefore, even if the pedal potentiometer 9 fails while the accelerator pedal 1 is being depressed, the abnormality is determined when the brake pedal 1 is being depressed and the throttle valve 7 is forcibly returned to the fully closed position, thereby preventing the engine from running out of control. It is also possible to prevent acceleration or engine rotational speed from being held at a high speed against the driver's will.

Once the fail flag is set to “1”, S12
If the abnormality in the pedal potentiometer 9 is still not resolved and there is no change in the accelerator pedal lOi position it β, the throttle valve 7 is maintained fully closed, but when the abnormality is resolved, the displacement β changes. S when the accelerator pedal 1 is released.
If the judgment in step 12 becomes No and the accelerator pedal 1 is depressed, the judgment in S13 becomes No and the process proceeds to 313. After the fail flag is reset to "0", the process proceeds to S7 and the throttle valve opening is returned to normal. Returned to control.

<Effects of the Invention> As explained above, according to the present invention, in an accelerator control device that electronically controls the throttle valve opening according to the displacement amount of the accelerator pedal, an abnormality in the displacement amount of the accelerator pedal is detected when the brake pedal is depressed. Because of this structure, the means for detecting the amount of displacement of the accelerator pedal deteriorates over time or malfunctions, and a signal that does not correspond to the actual accelerator pedal position is output, causing the driver's It is possible to effectively prevent the engine from accelerating against one's will or from holding the engine at a high rotation speed, improving safety.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is an overall configuration diagram showing an embodiment of the present invention, FIG. 3 is a flowchart showing a control routine of the above embodiment, and FIG. 4 is a flow chart of the same embodiment. FIG. 5 is a diagram showing the characteristic of the target value of the throttle valve opening with respect to the displacement amount of the accelerator pedal, and FIG. 5 is a diagram showing the characteristic of the control amount of the throttle valve opening with respect to the deviation of the same embodiment. 1... Accelerator pedal 4... Pedal potentiometer 5... Controller 7... Throttle valve 8
... Servo motor 9 ... Valve potentiometer 12 ... Brake pedal 13 ... Brake detection switch

Claims (1)

[Claims] Pedal displacement detection means for detecting the displacement of an accelerator pedal operated by a driver; and control signal generation means for generating a control signal for throttle valve opening based on the accelerator pedal displacement detected by the detection means. In an accelerator control device for an internal combustion engine for a vehicle, the accelerator control device for a vehicle internal combustion engine comprises a throttle valve driving means for opening and closing a throttle valve so that the valve opening corresponds to the control signal, and detects that a brake pedal of a vehicle is depressed. and abnormality determining means for determining whether or not there is an abnormality in the pedal displacement amount detection means by comparing the displacement amount of the accelerator pedal detected by the pedal displacement amount detection means when detecting depression of the brake pedal with a reference value. An abnormality diagnosis device for an accelerator control device for a vehicle internal combustion engine, characterized in that it is provided with: