JPH0635852B2 - Accelerator control device for internal combustion engine for vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic accelerator control device for a vehicle internal combustion engine, and more particularly to a device having a fail-safe function for dealing with a sudden abnormality detection signal.

<Prior Art> As an electronic accelerator control device for a vehicle internal combustion engine,
For example, there is one as shown in JP-A-59-58131.

In this, normally, the stroke of the accelerator pedal and the opening of the throttle valve are electrically detected, and the throttle valve is opened and closed by the actuator so that the throttle valve opening corresponds to the stroke position of the accelerator pedal. Further, when the clutch is connected, the throttle valve opening is controlled to prevent the clutch from slipping so that the engine speed that matches the vehicle speed can be obtained regardless of the stroke position of the accelerator pedal.

<Problems to be Solved by the Invention> By the way, in such an electronic accelerator control device, since the stroke position of the accelerator pedal and the throttle valve opening are detected by an electric means such as a potentiometer. However, if these detection means are deteriorated or deteriorated due to aging, etc., the detected value may change suddenly and drastically.If the throttle valve is opened / closed according to this detected value, the drivability deteriorates. However, in the worst case, there was a problem that the car could not be operated.

The present invention has been made in view of such conventional problems, good throttle valve opening control by eliminating the effect of a sudden abnormality of the detected value of the stroke position and throttle valve opening of the accelerator pedal. An object of the present invention is to provide an accelerator control device for an internal combustion engine for a vehicle, which is made possible.

<Means for Solving Problems> Therefore, according to the present invention, as shown in FIG. 1, the pedal position detecting means A for detecting the stroke position of the accelerator pedal operated by the driver and the intake system of the engine are provided. The throttle valve opening detection means B for detecting the opening degree of the provided throttle valve, the control signal generation means C for generating a control signal of the throttle valve opening according to the detection value from these detection means, and the control signal An accelerator control device for an internal combustion engine for a vehicle, comprising: a throttle valve driving means D for driving a throttle valve to open and close so as to have a corresponding valve opening degree; and detecting at least one of a stroke position of an accelerator pedal and a throttle valve opening degree. An abnormality detecting means for detecting that a sudden abnormality has occurred when a state in which the rate of change of the value is equal to or more than a predetermined value occurs a predetermined number of times or more within a predetermined time,
A configuration provided with a fail-safe means F for controlling the throttle valve opening by using a value obtained by performing a low-pass filter arithmetic processing by weighted averaging the present value and the past value of the detected values when the sudden abnormality is detected. And

<Operation> With this configuration, when the detected value of the accelerator pedal position or the throttle valve opening suddenly changes, failsafe processing is performed by detecting this state, and good throttle valve opening control can be performed. .

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

FIG. 2 shows the overall construction of the first embodiment. In the figure, an accelerator pedal 1 operated by a driver is axially supported by a floor panel 2 and is biased by a return spring 3 in a direction of returning to an idle position. As a means for detecting the stroke position of the accelerator pedal 1, a pedal potentiometer 4 is attached to the floor panel 2, and the detecting means from the pedal potentiometer 4 is input to an A / D converter 51 of a controller 5.

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

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

The controller 5 is configured to include each processing unit as follows. That is, the A / D converter 51 converts the analog signal from the pedal potentiometer 4 and the valve potentiometer 9 into a digital signal. The microcomputer 52 is the A /
While a signal from the D converter 51 is input and a control signal obtained by performing arithmetic processing to match the opening of the throttle valve 7 with a target value is output, the detection value of the stroke position of the accelerator pedal 1 is suddenly increased. When the abnormality is detected, the control signal is set by using a value obtained by correcting the detected value instead of the detected value. That is, the microcomputer 52 has a function as a control signal generating means, an abnormality detecting means, and a fail-safe 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 drive.

Next, a throttle valve opening control routine by the microcomputer 52 of this embodiment will be described with reference to the flow chart shown in FIG. This flow is activated by an operating system (not shown) at regular intervals (for example, 5 mS).

In S1, the stroke position 1 of the accelerator pedal 1 is read based on the signal from the pedal potentiometer 4,
In S2, the detected value θ of the throttle valve opening is read based on the signal from the valve potentiometer 9.

In S3, the difference between the current stroke position 1 of the accelerator pedal 1 read in S1 and the stroke position l ^* read in the previous flow, that is, the change amount Δl (absolute value) of the stroke position for 5 mS is calculated.

At S4, the value of the stroke position l for the calculation at S3 is set to l ^* .

In S5, it is determined whether or not the change amount Δl of the stroke position obtained in S3 exceeds the upper limit value Δlmax under normal conditions. If it exceeds, the abnormality counter is incremented in S6, and the process proceeds to S7. If not exceeded,
Skip S6 and proceed to S7.

Here, Δl is about 0.5V. That is, it takes about 80 mS to depress the accelerator pedal from the zero position to the maximum stroke position at the maximum speed, and if the voltage change of the pedal potentiometer 4 during this period is 0 to 5 V, the maximum voltage change of 5 mS is 0.31. V. There is a margin of 0.
Set to 5V. If the change in voltage value exceeds this (a sudden abnormality), it is abnormal.

In S7, it is judged whether or not the count value C _{1 of the} abnormality counter has reached a predetermined value C _M (for example, 5 times) within a set time measured by a timer counter described later, and if it has reached, a pedal potentiometer is determined. It is determined that there is an abnormality in 4 and the fail flag is set to "1" in S8, and then the process proceeds to S9. If C ₁ does not reach C _M , S
Skip 8 and proceed to S9.

In S9, the timer counter is incremented, and in S10, it is determined whether or not the count value C ₂ of the timer counter reaches a predetermined value C _N (for example, 200), and when C ₂ = C _N , that is, , Abnormality determination time (200 when C _N = 200)
Every time 5 mS = 1 S), the count value C _{1 of the} abnormality counter and the count value C _{2 of the} timer counter are calculated in S11.
Is reset to “0”.

Next, in S12, it is judged whether or not the fail flag is set to "1". If it is set, that is, if it is judged that the pedal potentiometer 4 is abnormal, the process proceeds to S13 after this judgment and the detected value is detected. A new stroke position L is set by performing low-pass filter calculation processing on l.

This is processed by, for example, an arithmetic expression based on a weighted average as shown in the following expression.

L ← K ₁ l + K ₂ L ^* Here, K ₁ and K ₂ are both positive values, and K ₁ + K ₂ = 1 is set, for example, set to have a function of cutting frequency components of 2 Hz or higher. . L ^* indicates the weighted average value of the previous time. Note that the stronger the value of K _2, the stronger the low-pass filter function (the function of cutting lower frequency components) can be obtained.

Thus, when the determination in S12 is normal, S13 is skipped and the process proceeds to S14, and when the determination in S12 is abnormal, S13 is performed.
And proceed to S14.

In S14, when the pedal potentiometer 4 is normal, S1
Stroke position 1 of the accelerator pedal 1 read in
Further, at the time of abnormality, the target value θ ₀ of the throttle valve opening with respect to the stroke position is calculated using the stroke position L subjected to the low-pass filter calculation processing in S13.

In S15, the deviation ε between the target value θ ₀ of the throttle valve opening and the detected value θ is calculated.

In S16, the throttle valve opening control amount Δθ with respect to the deviation ε.
To calculate.

In S17, a control signal corresponding to the control amount Δθ of the throttle valve opening is output to the D / A converter 53. As a result, the analog signal converted by the D / A converter 53 is amplified by the servo variber 54 and output to the servo motor 8, and the servo motor 8 is rotationally driven by a predetermined angle corresponding to the control amount Δθ to open / close the throttle valve 7. To be done. Then, by repeating such control until the deviation ε becomes 0, the opening degree of the throttle valve 7 is controlled to the target value θ ₀ .

In this way, when the pedal potentiometer 4 is deteriorated due to secular change, or when a sudden abnormality occurs in the detected value l as shown in FIG. 4 due to a failure or the like, the number of abnormality occurrences per predetermined time Is measured to determine an abnormality of the pedal potentiometer 4, and if it is determined to be abnormal,
The throttle valve opening is controlled by using the value L obtained by performing the low-pass filter arithmetic processing on the detected value l and removing the influence of sudden abnormalities as much as possible, so the throttle valve opening changes abruptly. Can be prevented, and stable operability of the engine can be maintained.

When it is determined that the pedal potentiometer 4 is normal, the detected value 1 is used to perform the normal and highly accurate throttle valve opening control.

In the present embodiment, the low-pass filter arithmetic processing is performed after the abnormality is judged. However, if the abnormal value is still caused by this, the arithmetic processing having a stronger low-pass filter function (the above K _{2 is set} to be large). May be performed.

Further, when an abnormality determination is detected, the servo motor 8 may be turned off, or fail-safe processing may be performed to keep the throttle valve opening constant after a predetermined rotation of the engine.

In the embodiment described above, the failsafe process is performed by detecting a sudden abnormality in the detected value of the stroke position of the accelerator pedal, but a sudden abnormality in the detected value of the throttle valve opening is detected. Fail-safe processing may be performed. Further, if both of these abnormalities are detected and fail-safe processing is performed, better throttle valve opening control can be performed.

<Effects of the Invention> As described above, according to the present invention, in the accelerator control device for driving the throttle valve by the drive means separated from the accelerator pedal, at least one of the stroke position of the accelerator pedal and the throttle valve opening degree. Since the configuration is configured to detect a sudden abnormality in the detected value of and to perform fail-safe processing that copes with the abnormality, it is possible to prevent the sudden change of the throttle valve and maintain stable drivability of the engine. To be

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is an overall configuration diagram showing a first embodiment of the present invention, and FIG. 3 is a flow chart showing a throttle valve opening control routine of the same embodiment. FIG. 4 is a time chart showing a sudden abnormality occurrence state of the detected value of the accelerator pedal stroke position. 1 ... accelerator pedal, 4 ... pedal potentiometer, 5 ... controller, 7 ... throttle valve, 8 ... servomotor, 9 ... valve potentiometer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location F02D 45/00 364 J 7536-3G (72) Inventor Akira Takei 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Within Nissan Motor Co., Ltd. (56) Reference JP-A-57-26232 (JP, A)

Claims (1)

[Claims] 1. A pedal position detecting means for detecting a stroke position of an accelerator pedal operated by a driver, a throttle valve opening detecting means for detecting an opening degree of a throttle valve provided in an intake system of an engine, and these detecting means. Control signal generating means for generating a control signal of the throttle valve opening according to the detection value from the means, and throttle valve driving means for driving the throttle valve to open and close so that the valve opening corresponds to the control signal. In an accelerator control device for an internal combustion engine for a vehicle, when the rate of change of the detection value of at least one of the stroke position of the accelerator pedal and the throttle valve opening is equal to or more than a predetermined value occurs a predetermined number of times or more within a predetermined time. Abnormality detection means for detecting that a sudden abnormality has occurred, and when the sudden abnormality is detected, a value obtained by performing low-pass filter arithmetic processing by weighted averaging the present value and the past value of the detected value. Accelerator control apparatus for an internal combustion engine for a vehicle, characterized in that the fail-safe means, the provided for controlling the throttle valve opening with.