JPS61279752A - Method of controlling idling speed of internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to interactive idle link speed control with direct fuel control.

BACKGROUND OF THE INVENTION Various idle link speed control devices for internal combustion engines are known. Such devices may be primarily mechanical or primarily electronic.

One of the goals of these devices is to increase the stability of the engine's idle link. Attempting to quickly respond to changing conditions in order to stabilize the idle link may cause overshoot or other instability of the desired fitting.

U.S. Pat. No. 4,328,775, No. III, discloses a closed loop idle control system for an internal combustion engine that includes a differential signal generator that generates an engine speed error signal. The signal passes through phase compensation and directly controls ignition timing for fast loop control of speed. The engine speed error signal also controls throttle position through an integrator connected in series with the phase compensator. The integrator, along with the phase compensator, forms a low speed loop that eliminates engine speed errors to avoid increasing exhaust pollutants.

U.S. Pat. No. 4,338,899 describes the ignition of a spark-ignition internal combustion engine in which a high air/fuel mixture is pumped to obtain a stabilized idle speed approximately equal to the desired idle speed. A technique for controlling timing is disclosed. From the nominal lag condition, the engine ignition timing is controlled to linearly advance the ignition timing in proportion to changes in engine speed below the desired speed. Ignition timing advancement can be achieved through a constant time delay and has the same ratio to engine speed changes as the ratio of the nominal ignition pulse interval to the desired engine idle speed.

US Pat. No. 4,344,397 discloses a technique for stabilizing engine idling speed using a continuous three-stage control device that sequentially adjusts ignition timing, fuel consumption, and air intake.

U.S. Pat. No. 4,142.483 discloses a read-only memory (read-only memory) programmed to generate multi-bit digital signals used to determine operating times.
An internal combustion engine operation timing control device using a ROM (ROM) is disclosed. One input to the ROM is provided by a speed counter and the other input is provided by another engine parameter transducer. The digital output of the ROM is provided to a timing counter. A main clock is used for clocking the speed and timing counters.

U.S. Pat. No. 4,262,643 discloses an internal combustion timing control system that generates periodic control pulses that are offset from periodic engine timing reference pulses. A processing circuit includes a counter connected to a Nant gate to generate a control pulse when a predetermined count is reached, a monostable device to which a control pulse can be applied to reset the counter, and a Brillault □de. - an oscillator that applies a preload pulse to the counter for a predetermined period of time to set the count, and one revolution per engine revolution to increase the preload count until the preset count is reached;
Receives a reference pulse to send a teaching signal pulse,
□ Phase rotation thereby generating control pulses
(Including Kudo Loop.

US Pat. No. 4,389,989 discloses an electronic device □ for stabilizing the idle link between a signal transmitter for the formation of an ignition spark and an ignition system of an internal combustion engine. When the engine speed decreases □, the ignition timing advances below the first engine speed.
□ and then obtained from the signal transmitter. pa
−′ pulse is delayed and the intended undelayed pulse 1□[) 1,・ The delayed pulse is advanced in the
:) 1. It is sent as a signal to the ignition device, thereby causing the °th
・1, a stable range between the low engine speeds of 1 and 2).

Do.

If no undelayed pulses are generated outside the
;stomach.

It is necessary to further stabilize the engine speed. In particular, it is desirable to control the width of the fuel pulse and the air intake of the engine to provide faster response to idle link speed variations.

SUMMARY OF THE INVENTION The present invention includes a method for controlling the idle speed of an internal combustion engine fed with a rich mixture. The air fuel ratio is
The range is such that the higher the air-fuel ratio, the higher the torque. A speed error is generated as a function of the difference between the desired engine idle speed and the actual engine idle speed. A fuel pulse width command signal is generated to control fuel delivery as a function of the speed error signal. A throttle command signal is generated as a function of the time integral of the speed error as well as the phase compensated speed error.

Following such operation, engine torque is limited by the amount of air supplied, so the main control loop is in the throttle position and the fuel controller tracks the air control. Air and fuel are controlled simultaneously while the speed is fluctuating. However, in steady state, by using the filtered manifold pressure signal, the fuel pulse width follows the air intake temperature.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, an interactive air-fuel and ignition idle control system 10 includes an idle link speed error adder 11 that includes inputs that indicate the desired fitting set speed and the actual idle speed error adder. and receives an input that supplies an idle speed of . It is calculated by speed computer 12 responsive to signals from crankshaft position sensor 13. The speed error signal from adder 11 is provided to phase compensator/amplifier 14. The output of this phase compensator/amplifier 14 is applied to an adder 15. Another input terminal of the adder 15 is supplied with the output of the temperature 1-sado wave corrector 28. The output signal of the manifold pressure sensor 17 is
Represents the pressure applied to the phase compensator/amplifier 16. The output of this phase compensator/amplifier 16 is a pressure compensated signal,
A temperature corrector 28 is provided. A signal representing the air temperature and a signal representing the engine cooler temperature are provided to the temperature modifier 28. The output of adder 15 is a fuel pulse width signal and is provided to fuel injector drive circuit 18, which provides fuel to the engine.

The engine 19 pumps air through the intake manifold and the throttle 20
receive through. A throttle position servo 21 controls the position of the throttle 20 and receives input from a phase compensator/integrator 22 . This phase compensator/integrator 22 is connected to the adder 11
receives the output of as input. Ignition module/distributor 2
3 causes spark discharge to occur inside the engine 19 and receives input from the advance angle circuit 24. The advance angle circuit includes a calculator that calculates the advance angle. The advance angle circuit 24 is a constant delay ignition timing circuit 2.
Contains 5. The constant retard ignition timing circuit 25 receives inputs from the crankshaft position sensor 13 and the retard correction advance circuit 26. The advance angle circuit 26 receives the output of the speed computer 12 as an input.

The method of the invention carried out in the apparatus shown in FIG.
-5CL, r,
jl! iF411i11me.

Follows the intake air density. According to the present invention, position Ige
M (ffig h t= i [;is *, t
y to rz + h (7)II rim >t
c.

The throttle position is changed proportionally to return the engine to its set idle link speed. The advance of the ignition angle is changed in proportion to the speed error. to maintain the desired air-fuel ratio when the speed error and its derivative are equal to zero.
The fuel pulse width is varied proportionally to the filtered value of manifold pressure. To improve the transient response of fuel pulses,
The fuel pulse width is also varied in proportion to the phase compensated speed error to provide a stable return to the set idle speed.

As a result, engine torque is air limited in accordance with the present invention, so the main control loop is in the throttle position and the fuel control tracks the air control. It is advantageous to control air and chestnut simultaneously while the speed is fluctuating. However, under steady state conditions, the fuel pulse width tracks air intake via the waveformed manifold signal from the filter.

Refer now to FIG. The phase compensator/amplifier 14 includes a phase compensator 301 and an amplifier 302.
receives the speed error as input and provides an output to amplifier 302. The output of amplifier 302 is speed effect compensated and is provided to adder 15 in FIG.

Referring now to FIG. 3, phase compensation/amplifier 16 includes a phase compensator 161 and an amplifier 162, where phase compensator 161 receives a manifold pressure signal as an input and outputs an output to amplifier 16.
Give to 2. The output of amplifier 162 is a pressure compensated signal provided to temperature modifier 28 .

Next, referring to FIG. 4, the compensator/integrator 22 includes a phase compensator/amplifier 141, an integrator/amplifier 142, and a phase compensator 143. and the output of the phase compensator/amplifier 141 and the output of the integrator/amplifier 142 are provided to the adder 144. The output of adder 144 is applied to the input terminal of phase compensator 143. Phase compensator 1
The output of 43 is a throttle position command signal.

Referring now to FIG. 5, another embodiment of the phase compensator/integrator 22 uses proportional and integral functions and eliminates the phase compensator. In particular, the velocity error is applied to the input terminals of gain amplifier 401 and to the input terminals of the series circuit of integrator 402 and integrator 403. The output of gain amplifier 401 and the output of gain amplifier 403 are applied to adder 404. The output of this adder 404 is a throttle position command signal.

It can be seen that the manifold pressure sensor 17 of FIG. 1 is used in the velocity density device when dividing air flow rate by measuring manifold pressure and air temperature. Alternatively, this can be done using measurements from an air flow meter and air temperature and engine speed, or using measurements from an air quality flow meter and engine speed.

Although the present invention has been described above with reference to embodiments, it will be obvious to those skilled in the art that the embodiments can be modified in various ways.

For example, the particular method of calculating the ignition angle advance can be changed from that shown in the above embodiments.

[Brief explanation of the drawing]

1 is a block diagram of one embodiment of an apparatus implementing the interactive air-fuel and ignition idle speed control method according to the present invention; FIG. 2 is a detailed block diagram of the phase compensator/amplifier of FIG. 1; FIG. is a detailed block diagram of another phase compensator/amplifier in FIG. 1, FIG. 4 is a detailed block diagram of the phase compensator/integrator in FIG. 1, and FIG. 5 is a detailed block diagram of the phase compensator/integrator in FIG. 4. FIG. 3 is a block diagram of another embodiment of the invention. 12... Speed computer, 14.16... Phase compensator/amplifier, 22... Phase compensator/integrator, 25...
... Constant delay ignition timing circuit, 26 ... Delay correction advance circuit, 28 ... Temperature corrector. Applicant's agent Sato -Yu lζ FIG, l l”□ 1・ [・ , 1 zo

Claims (1)

[Claims] 1. A process of determining a desired engine idling speed; a process of determining an actual engine idling speed; and a process of determining the desired engine idling speed and the actual engine idling speed.
generating a speed error signal as a function of the idle speed difference; generating a signal as a function of air flow rate; and generating a fuel pulse width specification signal to control fuel delivery as a function of the measured air flow rate. and generating a throttle command signal that controls throttle air flow as a function of a speed error signal. 2. The method according to claim 1, further comprising the step of advancing the ignition timing in proportion to the speed error signal. 3. The method of claim 2, wherein the step of generating the throttle command signal includes a first signal proportional to a phase compensated speed error signal and a first signal proportional to a time integral of the speed error signal. A method comprising the step of summing a second signal. 4. The method of claim 3, wherein the step of generating the throttle command signal further includes the step of providing a speed error signal to a series phase compensator. 5. The method of claim 4, wherein the step of generating the fuel pulse width command signal includes a first signal proportional to the phase compensated speed error signal, an air temperature, a coolant temperature and and a second signal that is a function of intake manifold pressure. 6. The method of claim 5, wherein the second signal for generating the fuel pulse width command signal includes a phase compensated signal representative of engine intake manifold pressure.