JPS58187556A - Processing device for internal-combustion engine controlling signals - Google Patents

Abstract

PURPOSE:To prevent a low-pass filter from functioning to equalize pulsating signals and to improve its responsibility at the time of acceleration, by utilizing comparative results of difference of input signal level and output signal level with their respective preset levels. CONSTITUTION:An electronic control system for an internal-combustion engine is adapted to input to a computation control circuit 26 outputs from a suction air tube 16, an air-fuel ratio sensor 22 and the like for controlling a fuel injection valve 17 and an ignition system 18 etc., by computing a fuel injection quantity, an ignition timing and the like. In this case, as for instance, a signal processing device for connecting a detection signal PBIN from a suction air tube pressure sensor 16 with a computation control circuit 26 is constituted as a low-pass filter, and the input signal PBIN is supplied to an integrating circuit constituted by a resistor R1 and a condenser C1, thereby obtaining an output signal PBOUT wherein pulsations of the detection signals are equalized. Moreover, the resistor R1 can be short-circuited via diodes D1 and D2 when there is a difference in voltage of, for example, 0.6V or more, between opposite ends of the resistor R1, and thereby preventing the low-pass filter from functioning.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used to electrically control the fuel injection amount, ignition timing, secondary air amount, etc. of an internal combustion engine, and is used, for example, to control an internal combustion engine that processes a pulsating intake pipe pressure signal. The present invention relates to a signal processing device for use in a computer.

When performing electronic control of an internal combustion engine, for example, tracheal pressure, intake air amount, etc. are detected, and the detected signals are used as input signals for electronic control. Such a detection signal is
Rotating combustion cider of internal combustion engine8. It is a signal that pulsates with the
In order to perform control testing, it is necessary to remove the pulsations in the detection signal, extract the average value per combustion cycle, and supply it to the control system circuit. For this purpose, the detection signal is supplied to a signal processing circuit consisting of, for example, a low-9 Re filter consisting of a resistor and a capacitor, and the signal averaged by this signal processing circuit is supplied to the electronic control unit of the internal combustion engine. ing.

Now, taking the example of a 4-cylinder, 4-stroke internal combustion engine for automobiles, the normal operating speed range of this internal combustion engine is 600 to 6000.
rpm, the pulsation frequency ON, ff of the detection signal is 20 to 200 Hz. Here, the number of revolutions is 60 Orp
In order to make the pulse 1IjJ rejection rate (gain) of the above Re filter 0.1 (-20dB) when However, it takes about 80 minutes to reach 63 levels of the input signal level and level. If pressure is applied to suppress the pulsation of the RC filter to a low level, the response to the input signal in the form of a step or a signal (detection signal during acceleration/deceleration) will deteriorate. That is, it becomes difficult to improve the control responsiveness of the internal combustion engine during acceleration or deceleration operation.

This invention is based on the above points, and is designed to effectively use a signal that pulsates in accordance with the rotation period of an internal combustion engine as a signal to an electronic control system that controls the engine. It is an object of the present invention to provide a signal processing device for an internal combustion engine that can perform pulsation processing that reliably follows the pulsation, especially during acceleration or deceleration operation.

That is, the signal processing device according to the present invention is equipped with a low-noise filter that averages a pulsating signal, and also has a state where the input signal level and the output signal are smaller than a specified value. [Out, at the time of this detection, the upper l low-pass filter is shunted t-11! This is so that the level of output No. 01 is reduced to the level of the input signal.

An embodiment of the present invention will now be described with reference to Figure (3). The fr1 diagram shows an outline of the internal combustion engine ca'm+ control system related to this invention. , combustion air is taken in through the nib cleaner 12 , the throttle machine @ 13 , the sensor 14 , and further through the intake pipe 15 . And in Sarno tank 14t11,
An intake pipe pressure sensor 16 is provided, and the intake pipe pressure corresponding to the amount of intake air per revolution of the ennon 11 is changed to the Kamekirakugo and taken out. As for j16, a diafunmu-style one-defeat one is used, such as q, beef, body, friend, metal temple, t#, and so on.

Also, regarding the yeN injection valve 17 of Ennon 11,
Fuel is supplied from a fuel system not shown in the figure, fuel is injected from this injection valve 11, and high pressure signals for ignition are sent to the igniter and coil.

It is supplied to the ignition system JJI, which consists of 7" 4 stripes, 2 stripes, etc.

The exhaust gas after combustion of the engine 11 is transferred to the exhaust manifold J.
9. Wfi pipe j O1 It is discharged into the atmosphere via the catalyst co/perme 21, etc., and this exhaust system is provided with an air-fuel ratio sensor 22 that detects the oxygen concentration in the exhaust gas.

In addition, the throttle mechanism 13 includes a throttle opening sensor 23, and an intake air temperature sensor 24 associated with the intake pipe 16.
A rotation sensor is provided in the ignition system 18, and a rotation sensor is provided in the ignition system 18, and a cooling water temperature sensor 25 is provided in the main body of the engine 110.
t-provide. And the intake pipe sensor? 16, air fuel ratio sensor v
Along with the signal from the ats, the throttle opening sensor 23,
Detection signals from the intake air temperature sensor 24, the cooling water temperature sensor 25, and the rotation center are sent to an arithmetic control circuit 26 made up of a computer, and are used to determine the opening/closing timing of the fuel injection valve 17 and the ignition system 1.
80 energization ignition timing, EGR control system (not shown), idle speed (auxiliary air t) control system 4! It controls the

Figure 2 shows, for example, the detection signal of the intake pipe pressure sensor 16)
A signal processing device is shown for coupling to the control circuit 26. The detection signal from the sensor 16, that is, the input signal Pa1n to this processing device, is supplied to an integrating circuit consisting of a resistor R and a capacitor C1, and the detection signal is The pulsations are averaged and output as an output signal P1°. That is, this signal processing device is configured as a low-pass noilter, and its output symbol is P. , is supplied to the υ converter in the arithmetic control circuit 26, and is subjected to arithmetic processing as distal data.

Therefore, the pulsation shown by the broken line in FIG. 3 superimposed on the detection signal from the intake pipe pressure sensor 16 is caused by the resistance R.
1 and the time constant determined by capacitor C1,
The pulsation is removed, and a signal with an average value as shown by the solid line in FIG. 4 is output as an intake pipe pressure signal.

Also, the above Rono? The resistor R1 that constitutes the filter is connected to diodes D1 and D, which are connected in parallel and have opposite directions.
2 is connected. This diode DI, D2 is a resistor R1
, that is, the input signal Pgin and the output signal P1
For example, this prevents ゜□ from being separated by more than 0.6V. That is, the output signal PBout after the pulsation process is always within 0.6 V with respect to the input signal P□nK from the intake pipe pressure increase sensor 16. Accordingly, the pulsation accompanying the rotational operation of the engine 11 is 0.6 in the wave volume value of the intake pipe pressure signal.
If it is within V, the average value is processed as shown by the solid line in Figure 3. If the intake pipe pressure signal fluctuates greatly due to acceleration or deceleration, the resistor R1 is short-circuited by diode DI,02, and the low P The output signal P1° follows □Y.

That is, the diodes D1 and D2 effectively remove the pulsation component and provide the arithmetic control circuit 26 with an intake pipe pressure signal that is sufficiently responsive to large fluctuations in intake pipe pressure during acceleration and deceleration. As a result, engine control with sufficiently improved responsiveness can be performed.

In the above embodiment, the diodes D1 and D2 set the allowable potential difference between the input signal from the intake pipe pressure sensor 16 and the output signal after pulsation processing, and then this allowable potential difference can be set arbitrarily. Then, it is very effective for enJ)/control.

Figure 4 shows a ninth embodiment in which an active filter is used in place of the Re primary filter of the above embodiment, and it is an au pair! OP1, OPj, resistors R2°RJ, converters C2, CI constitute an active filter, and operational amplifiers OPJ and OF4 constitute a converter.

That is, the detection signal from the intake pipe pressure sensor IC is supplied as an input signal P□ to a Puffau (amplifier OPJ).This operational amplifier fOP1 is operated as a logic follower, and its output voltage v1 corresponds to the input voltage. Then, the output voltage signal including pulsations from the operational amplifier foil is output from the resistors R2 and R3 and the capacitor C.
The intake pulsation signal included in the intake pipe pressure signal is removed by a low-pass active filter consisting of 2°C3 and an operational amplifier OP2. This ζ is the resistance RJ.

The constants of RJ, capacitors cz, and cs are determined by the shape of the frequency characteristics of the filter and the cutoff frequency f. For example, in the case of a Butterworth filter, they are calculated by the following equation.

FIG. 3 shows an example of a waveform in the case of a Chebyshev filter with overshoot, where the force and to-off frequency f are determined by the required pulsation removal rate at the idle speed.6For example,
In the case of a 4-cylinder engine, the Butterworth filter constant that obtains a pulsation removal rate of 0.1 at 600 rpm is "C2 = 1
μF”rc, y=o, aaμFJ rR2=zzkΩ
” “R3=82Ω”.

As during acceleration, the intake pipe pressure signal exceeds the intake pulsation range and rises as shown in Figure 3, and the input voltage ■1 becomes the output voltage v2.
Reference voltage vT11 applied to operational amplifier OP4
Assume that it has increased by 1 or more. Resistors R4 and R5 of the circuit for opamp OP 4 and R6 and R7 + R9
/R10 (parallel resistance value of R9゜FLIO) will be equal to each other.'' If you choose the resistance constants like this, the voltage at the ←) @ input of operational amplifier OP 4 will be ``(V, □ + v2) / 2'', ←) Personal power. The voltage is rv, /2J (when the output of operational amplifier 0P4 is low level). And [■, 〉v2+v□
, '', the output voltage of the operational amplifier OP4 is inverted and becomes a high level, and the F transistor Tr1 is controlled to conduct through the resistor RJ and the diode D3, and the voltage v2 becomes the voltage V.
, set to follow.

When the acceleration operation is completed and the stable state is returned again, the input voltage r(V□ on the amplifier OF 400 side) at that time.

10V2)/2J←) input voltage r(V□, //+V,
)/2J), the transistor Trld becomes non-conductive and the pulsation processing active filter comes into operation. Transistor Tr 1 is rVl-Vz〉■□,''
When the 1-skin conduction state occurs under the condition of , the output is positively fed back to the (+) inputs of the operational amplifier OP4, so r
""-1' is not reversed to non-conducting state unless it becomes 11 JK.

Note that the above voltage V□,〃 is determined by R#, R11), and is determined by resistors Rj, RJ, capacitor ? Cj.

It can be set arbitrarily according to the active filter's input/output phase difference, overflow, and exhaust amount determined by CI, and the intake pipe pressure waveform. During deceleration, turn off (amplifier OP j
When the engine stabilizes in a steady state after deceleration, the transistor TrI becomes conductive, and when the engine stabilizes in a steady state after deceleration, the transistor Tr2 becomes non-conductive, so that this circuit operates as a normal pulsation processing active filter in the same way as after the spinning acceleration.

Although this example uses a second-order active filter, it is better to use a second-order active filter to realize the sharp frequency characteristics, that is, the sharp dependence of the pulsation removal rate on the engine speed. The following filters can be used: Acceleration/deceleration detection and steady state detection when configuring a multi-stage filter with two or more operational amplifiers are performed by inputting and outputting the input and output voltages of the filter to the operational amplifier OP3, as in the case of the above-mentioned secondary active filter.
OP 4 Con/? transistor Tr1. Tr 2 may be used to control execution and stop of the pulsation process.

Furthermore, active filters include LC filters consisting of coils and capacitors, and ceramics.

It is also possible to add control during acceleration and deceleration to a filter or the like.

Furthermore, in the above embodiment, the intake pipe pressure signal in the internal combustion engine control system is exemplified, but this is based on the intake air amount, the EGR (exhaust gas recirculation II) amount, the intermittent combustion of the internal combustion engine such as the secondary air spear, etc. This can be similarly applied to the processing of all affected engine state detection signals.

As described above, according to the present invention, pulsation of control parameter signals that inevitably occur due to intermittent combustion that exists in an internal combustion engine is reliably processed, and responsiveness during acceleration and deceleration is sufficiently satisfied. As a result, internal combustion engine control such as improved driveability, improved fuel efficiency, and purification of exhaust gas can be executed very smoothly.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a system t of an internal combustion engine related to the present invention, FIG. 2 is a circuit diagram illustrating a signal processing value f according to an embodiment of the present invention, and FIG. 3 is a signal waveform diagram as well. , and Figure 4 are circuit diagrams showing other embodiments of the present invention. DESCRIPTION OF SYMBOLS 11... Engine, I5... Intake pipe, 16... Intake pipe pressure control circuit, 26... Arithmetic control circuit, R1... Filter resistor, CI... Filter capacitor, DI
, DI...diode. Client agent Patent attorney Hikosai Suzue Takeshi 1 Figure 12 Figure 2 Figure 3

Claims (1)

[Claims] A low/yas filter removes ripples in the input signal level and extracts an output signal at an averaged level, and the input signal level and output signal level are compared and the difference level is determined and is greater than the first value. and a first and second circuit whose conduction is controlled in a state where the value becomes equal to or smaller than the specified second value, and when the first and second circuits are conductive, the low-noise filter A signal processing device for controlling an internal combustion engine, characterized in that the output signal level follows the input signal level.