JPH01190949A - Surge judging device for vehicle - Google Patents

Abstract

PURPOSE:To correctly judge the generation of surge of a vehicle by installing a judging means which judges the generation of surge when the sampling value of the vehicle acceleration signals exceeds a certain value. CONSTITUTION:An acceleration signal for a vehicle is supplied from an input terminal 1. A boost signal is supplied from an input terminal 21. The fluctuation of the boost signal as the output of a differential amplifier 25 is inputted into a comparator 32. The signal supplied from the comparator 32 turns-ON a switching element 34 when the fluctuation of the boost signal is small, while if the fluctuation is large, the switching element 34 is turned-OFF. The output of a differential amplifier 5 is inputted into a comparator 35 through the switching element 34, and when the input value exceeds a predetermined value, an output is supplied from the comparator 35, and the generation of surge is confirmed. Thus, the generation of surge of a vehicle can be correctly judged in quantitative ways.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for determining the occurrence of a surge while a vehicle is running.

(Prior art) In vehicles such as automobiles, due to malfunctions in the fuel supply or ignition system while the vehicle is in motion, the engine may misfire, resulting in uneven rotation and fluctuations in acceleration in the longitudinal direction of the vehicle. . Such a phenomenon is called a surge.

Conventionally, the occurrence of such phenomena has only been confirmed by the driver's senses, and quantitative confirmation has not yet been carried out. Confirmation of occurrence is an important judgment element in elucidating engine performance and fuel combustion characteristics.

(Problems to be solved by the invention) This invention makes it possible to quantitatively confirm the occurrence of surges while a vehicle is running, thereby making it possible to accurately judge the performance of the engine or the combustion characteristics of the fuel. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention samples the acceleration signal of the vehicle during a period when the fluctuation of the engine boost signal is small, and the sampling value exceeds a certain value. It is determined that a surge has occurred when .

(Function) The boost signal increases when the accelerator pedal is depressed, resulting in acceleration. Conversely, the boost signal decreases when the accelerator pedal is released, resulting in deceleration. Therefore, the acceleration signal increases or decreases in accordance with changes in the boost signal. Therefore, changes in acceleration are ignored during times when the boost signal fluctuates greatly, and changes in acceleration at other times are detected.

Therefore, by sampling the acceleration signal when the boost signal has small fluctuations, it becomes possible to detect that a surge has occurred in a vehicle that is traveling steadily.

(Example) An example of the present invention will be described with reference to the drawings. In FIG. 1, an acceleration signal as shown in FIG. 2A, for example, is applied from an input terminal 1 in accordance with the acceleration of the vehicle. Specifically, for example, an accelerometer provides a signal having a magnitude corresponding to the indicated value.

The acceleration signal is given as one input to a differential amplifier 5 via a peak detector 2 that detects a positive peak value P (see FIG. 2; the same applies hereinafter), a switch element 3, and a hold device 4. No. At the same time, it is applied as another input to the differential amplifier 5 via a peak detector 6 that detects a negative peak value N, a switch element 7, and a hold device 8.

To explain the operation with reference to FIG. 2, let us assume that the signal averaged by the low-pass filter 9 is the average value for the acceleration signal a shown in FIG. 2A.

The peak detector 2 detects each positive peak value P□ of the acceleration signal a,
P2. . . . , and the peak detector 6 detects the peak values N, , N, . . . of each member of the acceleration signal a.

Here, for example, when the acceleration signal a is larger than the average value, an output is output from the comparator 10 and inputted to the timing unit 11. Timer 11 turns on switch element 3 and turns off switch element 7 when an input is given to it. When no input is given to the timing device 11, the switch element 3 is turned off and the switch element 7 is turned on.

As a result, each peak value of the acceleration signal is sampled as shown in FIG. 2B, and the hold output by the hold device 4.8 is outputted from P, P2.8 as shown in FIG. 2B. ...
...and N Engineering, N2. It becomes...

Each hold output is processed by a differential amplifier 5, and the difference between the two is D□=P knee N1 D, = P, -N. ri, =P, -N2 D,=P3-N.

DS=P3-N.

Each is calculated as follows. FIG. 2C shows the waveform of the calculation result.

From the above results, it is possible to detect fluctuations in the acceleration signal. In other words, when the acceleration of the vehicle changes significantly,
The above-mentioned calculated value becomes large. However, when the acceleration changes significantly, it is due to a surge phenomenon that occurs when the vehicle is traveling at a constant speed, but the same is true when the speed changes by operating the accelerator pedal.

Therefore, in order to detect a surge phenomenon, it is necessary to exclude fluctuations in the acceleration signal caused by depressing the accelerator pedal. In other words, by detecting that the accelerator pedal is depressed and sampling the above calculation results during a period excluding that period, it becomes possible to determine whether a surge phenomenon has occurred.

Accelerator pedal operation can be determined by the boost signal from the engine. The boost signal is determined, for example, from the pressure in the engine's intake pipe.

Specifically, a pressure sensor that responds to the pressure in the intake pipe may be installed, and the output of this pressure sensor may be appropriately converted into an electrical signal to obtain the output.

An example of a boost signal is shown in FIG. 3A, assuming in this example that the accelerator pedal is initially released.

The throttle valve in the engine is closed, so the intake valve opens and tries to suck in air, but since the throttle valve is closed, it approaches a vacuum state, so the boost value is set to a negative large value (e.g. The average value is 176
0+a+Hg).

Next, if you press the accelerator pedal hard, the throttle valve will open. Even if the intake valve opens in this state, a vacuum state does not occur, that is, the boost signal changes greatly in the positive direction, and the value B2 (for example, the average value is Ommt
(near Ig).

After accelerating, if you release the accelerator pedal and press it down moderately, the vehicle will maintain a constant speed. At this time, the throttle valve is open approximately 50% during acceleration. Even if the intake valve opens in this condition.

The pressure in the intake pipe does not decrease as much as when it is vacuumed, and the value B2
(For example, the average value is -300 to -400ma+FIg
degree).

As understood from the above explanation, when the accelerator pedal is operated, the boost signal changes accordingly.

Each of the boost values BttBz+B described above is an average value, but actually fluctuates finely as shown in FIG. 3. It is sufficient to detect fluctuations from changes in this boost signal. The configuration for this purpose will be explained using figures.

In FIG. 1, when a boost signal is applied from an input terminal 21, a peak detector 22 detects its positive peak value Ai. It is applied as one input to the differential amplifier 25 via the switch element 23 and the hold device 24. At the same time, a peak detector 26 detects a negative peak value M□. It is given as another input to the differential amplifier 25 via the switch element 27 and the hold device 28.

Further, the boost signal is averaged by a low-pass filter 29, and the average value is used as one input of a comparator 30. A boost signal is directly input to the comparator 30. As a result, when the boost signal exceeds its average value, the comparator 30 outputs a signal as shown in FIG. 3C.

This signal is given to the timing device 31. The output from this timing device 31 causes the switch elements 23 and 27 to
On/off is controlled. Specifically, when a signal is output from the comparator 30, a signal is output from the timing unit 31, and the switch element 23, which had been turned off until then, is turned off.
is turned on. As a result, the positive peak value A1 of the boost signal is held in the hold device 24.

Also, when no signal is output from the comparator 30.

The signal from the timing device 31 at that time turns on the switch element 27, which had been off until then. As a result, the negative peak value M1 of the boost signal is held in the hold device 28.

As shown in the third diagram, each hold value of each hold device 24.28 is A 1HA z e... and Ml
, M2°...

The difference between each hold output is calculated by a differential amplifier 25.

E, = A knee M. E, =A, -M□ E,=A,-M.

E4=A, -M.

The calculations are performed as follows: E, =A, -M□. FIG. 3E shows the waveform of this calculation result. From the above results, it is possible to detect fluctuations in the boost signal.

The fluctuation of the boost signal that is the output of the differential amplifier 25 is given to the comparator 32 as one of the inputs. The comparator 32 compares the level signal L1 set by the level setter 33.

When the fluctuation of the boost signal exceeds a predetermined value (in other words, when the accelerator pedal is operated), the comparator 32 outputs a signal (see FIG. 2F).

The signal from the comparator 32 is connected to the output side of the differential amplifier 5 and controls the on/off of a switch element 34. That is, it is turned on when the fluctuation of the boost signal is small, and turned off when the fluctuation of the boost signal is large.

The output of the differential amplifier 5 is provided as one input to a comparator 35 via a switch element 34.

Another input of the comparator 35 is the level value set by the level setter 36 (see FIG. 2C).

) is given the corresponding signal.

Therefore, unless the boost signal fluctuates significantly due to operation of the accelerator pedal, the output of the differential amplifier 5 is input to the comparator 35 via the switch element 34, and the input value exceeds a predetermined value. When
The comparator 35 outputs an output as shown in FIG. 2F. The occurrence of this output confirms that a surge has occurred (see the second diagram).

Although the above embodiment has a configuration in which processing is performed in an analog manner, it is also possible to adopt a configuration in which processing is performed digitally using an AD converter, a microcomputer, etc. instead of this.

(Effects of the Invention) According to the invention described in detail above, it is possible to quantitatively and accurately determine the occurrence of a surge in a vehicle.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing one embodiment of the present invention;
This figure is a waveform diagram for explaining the operation, and FIGS. 3 and 3 are waveform diagrams for explaining the relationship between the boost signal and the output of the timing device. 1...Acceleration signal input terminal, 2.6, 22.26.
...Peak detector, 3.7, 23.27...Switch element, 4.8.24.28...Hold device, 11.3
1... Timing device, 5, 25... Differential amplifier. 1o, 3o, 32.35... Comparator, 21... Boost signal input terminal,

Claims (1)

[Claims] a detection means for detecting that the fluctuation of the boost signal of the engine is small; a sampling means for sampling an acceleration signal of a vehicle in which the engine is mounted; a sampling value sampled by the sampling means at the time of detection by the detection means; A vehicular surge determination device comprising a determination means that determines that a surge has occurred when a certain value is exceeded.