JPS59120751A - Method of controlling idling speed of rotation for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent the speed of rotation from lowering by controlling the idling speed of rotation using a multi-variable control means based on the dynamic model of an engine, allowing deviation in the speed of rotation to occur continuously by means of continuous disturbance, and varying the control input value when the disturbance is removed. CONSTITUTION:A state observing unit 13 is provided which stores a dynamic model of an internal-combustion engine 12, i.e., a controlled object, and estimates the dynamic inner state of the engine based on a pulse width PA which operates the control solenoid of a bypass-air quentity control valve, on ignition timing IT, and on the idling speed of rotation N, and a state variable quantity xi with a proper order representing the inner state is estimated in this unit 13. This estimated quantity is then sent out to an integration + gain block 14, where the values of two controlled inputs PA, IT are calculated from the quantity obtained by integrating the deviation SA between the target value Nr of the engine rotational speed and its actual value N. The control input value is provided so that the deviation SA continues to occur by means of continuous disturbance and a large variation in speed of rotation can be prevented when said disturbance is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for controlling the rotational speed of an internal combustion engine with four idle speeds, and more specifically relates to a method for controlling the rotational speed of an internal combustion
(Proportional Integral Derivative) Different from internal combustion, the internal state of the engine is taken as a fully dynamic (dynamic) system, and the internal state is taken as a fully dynamic system, and the internal state is defined by four state variables. Using the method of controlling the state variable '+1 flJ to determine the input variable of the input variable without estimating the intensity,
This invention relates to a method of increasing the idle rotation speed.

(Prior art) One method on the idle rotation speed ftflJ side in a conventional internal combustion engine is (・1, for example, as shown in FIG. 1. Idle rotation speed "m1") 1 Wholesale AAC valve 1fl, VCM valve By controlling the duty pulse width P4 of the solenoid 3 on the 3rd side of 2, the vertical direction of the lift changes, the amount of bypass air flowing through the bypass 5 of the throttle valve 4 changes, and the idle rotation speed changes. -Ino is done.

, the control unit 6 is idle (IDLE) by the throttle valve switch (idle switch) 7.
Signal, 211 tral by neutral switch 8 (
IJF:UT) signal, vehicle speed according to vehicle speed sensor 9 (VS
P) When it is known from a signal that the engine is at 1 residual or idle, the basic value of the idle rotation speed is determined using the one-dimensional table run knob according to the agitation water temperature thickness (T□) measured by the water temperature sensor 1°. H direct'x'A-put out.

Then, the air conditioner (A/C) is activated by the air conditioner switch 11.
) signal, neutral (MlσUT) signal, vanodelli pressure (VB) signal, etc.
For the N7, the pulses 'X and Il@PA of the input cylinder 3 are proportionally controlled so that the deviation SA between the engine's idle rotational speed N and its mark t'N is small. minute (PI) duty cycle 1] and target rotational speed N7. feedback control.

The above control method is shown in flowcharts in Figures 1 to 2.

However, in such a conventional internal combustion/end-to-end idle rotation speed control method, PI control is performed using the m% ratio of the engine, actuator 2, and sensor. Moreover, since PI control as a control method was not suitable for controlling a multi-input/output system, when the engine enters the idle state from other operating states, the Problem 9: when exiting from an idle state, or even immediately after various load disturbances are applied, when the input speed shows a sudden change, the control response is poor. There was. Also, in addition to the other ↑1"1" side, i+lJ'
There is a problem in that it is difficult to apply the Pl control method when trying to increase the full degree of freedom of l1rII and increase the facet angle.

And in the end, it is unpredictable] No. 1 function ki no mochi 7 play spring rannyo 9,
If N>Nr, the leech continues, and the amount of air flowing through the flo input becomes very small, and the sustained disturbance is suddenly removed, the engine speed margin will increase. Y11
I couldn't get it done in time, so I had to do 1 to 9 yen for the second time, so I wonder when it's going to be a problem./○ (Big brother's eyes go blank) This clarification is based on the existing problems like this. When the engine enters the idle state from another operating state or exits the idle state, Sashiku・'C is the time when the engine exhibits unusual behavior due to a load disturbance. The Ti1l-l 1tllll followability, that is, the transient response, is optimized, and a large number of control input variables are added to the control system, increasing the degree of freedom. 1. The purpose is to make it easier to set up the idle rotation speed, thereby achieving more stable idle rotation speed control. In particular, with the addition of unpredictable air shock disturbances, the amount of air ゛() becomes very low and the disturbance suddenly occurs. Even if the engine is removed, the purpose is to completely prevent the drop in engine speed and to control the engine stably.

(Details and effects of the invention) Accordingly, the present invention provides that when a model of the dynamic characteristics of an internal combustion engine, an actuator 2, and a sensor is stored in a controller consisting of a microcomputer or the like, the amount of air (or equivalent amount), ignition The period, amount of fuel supplied (or amount of phase drawn), and 9㎢ (di:GR)-Jut-C or equivalent amount) are either 1 or 2 of the lower 1.
The combination of three or more is controlled by human power, and the idle rotation speed is controlled by the power output, and the combination of two or more is controlled by human power. Estimating all the variables of the 5 flights, using the 1st constant 11 is the target 11α of the 1 rotation J4 + length and Pumi [the integral 1 of Goj I of the prefecture 1 shift], the input area of ? is determined, and the idle rotation speed of the internal combustion engine is feedback-controlled to a target of 11μ. It uses a method sound of multivariable open side j that increases 1IT11.And sometimes, due to unpredictable continuous disturbance of the air, the control force value is lower limit or lower limit. If the sustained disturbance is suddenly removed due to a run on one of the values, it is assumed that under certain conditions, the initial 11σ is applied to the direction in which the engine rotational speed increases. It is something that will be taken care of from time to time.

The following explanation will be based on this drawing.

FIG. 3 is a schematic diagram of an apparatus for implementing an embodiment of the method for controlling the idle rotation speed of an internal combustion engine according to the present invention.

In the same figure, 12 is an internal combustion engine that is immediately subject to control,
In addition to idle rotational speed control, the output of the 0 control target 12, which performs fuel injection control including air-fuel ratio feed bank control, is set to the idle speed 1 transmission speed, and the control input and [ In ~, the amount of air (the equivalent amount), the ignition timing, the amount of fuel (the equivalent amount) and the exhaust recirculation amount (the equivalent amount) Next, select any combination of two or more. In this example, 271;
II. As a decoration, the VCM valve 2 for adjusting the bypass air pressure w-1 / l / hour] Control Lenoid (Fig. 1) Fully driven panorama L > 7. Width PA (i.e. violet corresponding to bypass air amount) and ignition timing JT
! The output of in1 group is 1 output at idle rotation speed N.

13 stores a dynamic model of the control 141 and the home-generated engine 12, and inputs and outputs the above three 'interest input/output information F'.
It is a state observer that estimates the dynamic internal state of the engine from A, IT, and N. It is a state observer that estimates the dynamic internal state of the engine from A, IT, and N.
2+"Ss+"vector t・le representation of 4) is calculated.

State-11111 device 13 (is a simulation of the engine to be controlled, and is a dynamic internal state represented by the butterfly variable X (vectors x1 to x7 of order 71). Specifically, the state variables that represent the internal state of the 4 function 12 lines include, for example, the absolute pressure of the intake manifold, the suction negative pressure, the amount of air actually taken into the cylinder, the dynamic behavior of combustion, Engine torque, etc. can be detected by a sensor.If these 1 shifts can be detected by a sensor, the dynamic behavior can be completely understood by using the detected 1 shift, and ftjl
However, at present, there is no practical senna that can detect these values. Therefore, the internal state of the engine is represented by the four general states of evil.However, the state variable It's something that makes you laugh. Regarding the order mn of the state variable X, the larger n is, the more accurate the simulation will be, but on the other hand, the details of the calculation will be more complicated. Therefore, all low-approximations are used as models, and errors due to approximation errors or differences between individual engines are absorbed by integral operation. In this invention, approximately n-4 is appropriate for the two-man power one-output knitting.

In Fig. 3, 14 is an integral operation and gain block,
The deviation SA between l and the actual value N of the engine rotational speed to the specified target area and the state observation device 1
From the bad variable quantity X calculated in 3, there are two controls X1 human power P
A and ITO value? Calculate (see Figure 5).

The controller is entirely composed of the state observer 13, the integral operation, and the gain block 14.

Next action? explain.

匍j′＠The target engine 12 is a two-man power, one-output system, and the linearly approximated transfer function matrix ″f′ is obtained near the reference setting 1iN with rotation synchronization samples and chewing threads between the human outputs. From (z), it is possible to estimate the dynamic internal state of the controlled object 2. One of the methods is the state observation device Ko3 Karuru. Under continuous rotation conditions near the idle rotation speed, the transmission connection of the controlled object 12 is
(Z) is mei! Empirically, we find 1't'(z)=[T+(z
) 7'2(z)) (i). However, 2 indicates 2-conversion of 1 sample of the input/output signal, and 7
``1(Z) and 7'2(z) are quadratic transfer functions of 1 and 2.

Input, output 2 and transfer function T, (Z), 7' 2
Is the model Mizozo of 12 I subject (engine) to the side of the relationship of (z)? It is shown in Figure 4. However, Chikara Ota uses the deviations δPA, δIT, and δN from the standard setting values, respectively.

From this transfer open matrix '1' (z), the state observer 13id can be constructed as follows.

First, from 'f' (z), a state variable model that describes the dynamic behavior of the engine x (n) = Ax (n-1) + Bu (n-1)
(2) y(n-i) = Cx(n-1)
(3) Complete guidance. Here, (Q) in parentheses for capacity
represents the current time, and (n-1) represents the 1i sample time point.

u(n-1) is the lateral line vector, and a certain standard setting 1
From 1 turn, the entire 1'0 motion within the range where the deep approximation holds is expressed as t, pulse of control # solenoid 3 + 17δPA (
n+) The ignition timing δIT is set to 0. In other words, Y("'-') is the output j on the side j, and the control input vector and Ir1J are expressed as δ#(n-
z) is an element.

That is, y (n-1) - δN (n-1) (5) It is a fixed constant matrix.

Here, we have the following algorithm! Configure all p4 parent instruments.

x(i)=(A-GC)X(?1.-1)+Hu(
n-1)+(jlj(n-") (6) Here, G is an arbitrarily given matrix and is the estimated value of the internal state variable X(ri) of x(ri is the engine)2. (2) (3) Transforming from equation (6), [x(i)-x(n))-(A-(FC)[x(n-1
)-x(n-1)] (7) Tonaji, matrix (A-G
If we choose G so that the eigenvalue of C) is within the unit circle, then when n→large, we get X (?Z) −+ X (n)
(8), and the internal state variable x (n) can be estimated from the input U(·) and the output y(·). Also, choose the matrix G appropriately and write the row 1j (A-(-iC)
It is also possible to set all the characteristic ′lVi of 0 to zero, and in this case state 1? The cape j device 13 becomes a finite difference foot state observation device.

The deviation S between the state variable X(・) estimated in this way and the target rotational speed Nr and the current actual rotational speed N(・)
Using the information of A-(#?,-N(su)), 1 drive pulse 1m of iml '1illnrenoid 3 which is the control input PA standard setting 1 area (PA) Within the range where linear approximation from a holds true Determine the total weight of the engine's idle rotational speed N, δPA (and the standard setting of ignition timing 1W7: J. et al.'s 7th series, and the increase δIT(・) within the range that holds true, and determine the exact Hv of the engine's idle rotational speed N. Regulator control (Regulator control) means a constant value flil that is controlled to match the target rotation speed N?, which is the idle rotation speed N total value.
L side J all means.

lνIn this invention, as mentioned above, since the experimentally obtained model is an approximate model with reduced dimensions, an I (integral) operation is added (~ or here) to absorb all the approximation errors. Now, we will conduct the first search for an optimal regulator, including the I operation.

The engine of this invention is a two-man power one-output system as mentioned above, and the regulator is optimal for this system, but the optimal regulator for a general multivariable system is The threat 71J algorithm is, for example, Yoshi A1 Katsuhisa's ``Linear System Control Iyarigang'' (Showa 51).
Since it has been explained in Shokodo and others (2010), detailed explanation will be omitted here. If we describe only the result, now δu(n)-u(n)-u (?Z-i)
(9) δe(n) = N, -N'(n)
(10), and the evaluation function J is J−Σ[δR)2+δu'(k)Rδu(&), :]
(11) and O. Here, R is a weight parameter matrix and t is a transposition. The number of samples with the starting point as 0, (
11) Second term on the right side of equation 1rJ: f('Z represents the square of equation (9) if it is a diagonal matrix. Ox term t/1(9)
The equation is expressed as a quadratic form of the large control difference of lIM control, but this is because one operation τ month is added as shown in Fig. 5. Part j input U''(k) is (12).In equation (12), 1-t ---1- to -1 (B10B:P8) B PA (13
) and 2, 1( is the optimal gain matrix. Also, (1'
2) Since it is lonely in the equation, Pba・(1G) Nori Katti (R↑ccati) The stupidity of the evaluation function J of the equation 0(11), which can be solved by the solution of the equation, is the control human power U(R's movement k: While approximating ff1l, the idling force y(ri) is 11σ! The speed N r-i mark j [M N-,
This is intended to minimize the total deviation of 5A (f rotational fluctuation) from the rotational speed. Therefore, by selecting an appropriate R, using Seki's dynamic model (state variable model) at the idle stage, and formula (16), P kumquat i
''The optimal gain matrix of formula (13) (recorded in all microcomputers,
``The integral value of the deviation SA between Nr and the actual value N'' and from the estimated state variable It's all 0 dimensions that can be easily determined.As mentioned above, is the dynamic state of idan 1 ?Estimation of variables 1i@x(hm)?To find it, enter the matrix, B, c, C-A 1) 〇-KeMicrocomputer, -It is possible to calculate by formula (6) according to the following 1, ``-a''.

In addition, unpredictable 'fr, air ambush disturbance is added9,・
The state of 1 major rotational speed actual value Af > 1m1lηN per month continues) I washing 1 ~, jlijl side 1 input 1 Towards (retard side)! JJ! 2 D K, then control 'fa11 human power fiq T i) i) Empty'
fJ<% −, @ O! When the ignition timing suddenly changes and the engine speed changes and rises (because it does not move in the Q direction, the engine speed decreases and the engine stalls).

For example, when starting the engine, the bypass η that is done by the AC valve 1 increases the engine rotational speed. , when the throttle valve 4 (T1I diagram) is opened, the amount of disturbance air supplied by the throttle valve 4 and the idle rotation speed control gradually disappears due to the passage of time. The sum of the amount of air supplied by VCM valve 2 is the total air flow supplied to machine 1≠.At this time, the air wave supplied by throttle valve 4 is determined by the water temperature T117, etc. [If there is enough power to fully run the engine at the I target rotational speed anti-Na, then Nr, <N, and at the idle rotational speed '+l1lJ'# mark,
Naturally, the VCl discharge valve 2 is fully closed, that is, the control input air-oil production is minimized.

If the air regulator suddenly closes in this state, the VCM
Since valve 2 is close to fully closed, the engine rotational speed suddenly decreases to %)#, and the side leg is started in the direction of increasing the p1 bypass and ignition timing, but jv'? ,
If the <N state continues for a long time, it takes time for the integral element to flow out, and the state of Nr>H becomes erratic and the engine is likely to stall.

'f, k, 7. The throttle valve switch 7 (Fig. 1) used to determine the dollar value has a dead band, so when the vehicle is stopped, the throttle valve switch 7 must be pressed to the extent that it does not switch off. Even when the engine is in the vehicle and the throttle valve 4 remains open, the same thing as mentioned above will occur when starting the engine, and when the accelerator is released in that state, the air supplied by the throttle valve 4 will suddenly run out. The ignition timing at Ushidako is also retarded, causing the engine speed to drop suddenly and, if the engine is running poorly, to stall.

Therefore, as detailed above, is the state? If we do this, we add the estimated value x (=xi) of the adverse condition variable representative of the dynamic internal state of the engine, and at the same time add 1
Figure 6 shows one or more idle speed control operations that increase the amount of air that is input during 1st shift and simultaneously advance the ignition timing by 1IlIl (7 is 0 in Figure 6). Hand 1
To explain, in step 30, the idle rotation speed is changed to 1-. Decide on 1 mark N7. In step 31, is the actual rotational speed N less than (35C) rpm? If the air amount and ignition timing (i.e., human power for control) are below the lower limit of 1 shift (minimum 11N), step 32 is performed.
), and if it is the lower limit, the state is estimated 1fM+, 'Zl, OC2, Z3 in step 33.

Set x4'J3- and integral required purple DUN to 0, respectively.
One shift is required to maintain the control human power, one shift, and one machine rotational speed of 650 γpm. In step 34, the deviation 5h- of the idle rotation speed between the target page 11 Nr and the actual 41@H is determined.
t=r true. In step 35, the rotational speed deviation SA from the start of the control to the previous cycle is added, and the result is transferred to a register called DUN. In Sten 136,
The reference setting value Na of the actual value N of the rotation speed (for example, 650γ
Calculate the deviation δNk from pm). In step 37,
Dynamic internal state of the engine estimated in the previous IH cycle
and the calculated control manual shift δPA2 and δIT,
Furthermore, the valley state variables x1 to x4 are calculated by weighting and adding δN, which is the first output of 11I111. However, the matrix (A-ec) in Equation 6) is an example in which all finitely settled observers are formed.

Note that (A, J3.C) uses a branchable measurable quasiform.

In step 38, the estimated dynamic internal state of the engine and attitude quantities x1 to Oc4 are multiplied by the cumulative value of the DUNK optimal gain (kL) and added, and the results are calculated for the reference setting value (PA) av and ITa. ljJ Perform all calculations to determine how much to increase the input value.

Coefficients b, m, and 7 in Figure 6. etc., are calculated in advance and P
and store it in a micro combi coater, etc.

The results of experiments on the transient response to cyclic disturbances when the idle rotation speed is constant and the transient response when the target value r of the idle rotation speed is changed using the conventional PI control j The comparison between the multivariable control according to this invention and the multivariable control according to the present invention is shown in Fig. 7 (, 4) < FA or Fig. 10 (4).
(It is υ.

Figure 7 (A (E)) shows the transient response of the idle rotation speed N when the clutch is engaged at one point (the clutch is half engaged at the to point, but the brake is fully engaged), and (4) shows the conventional PI control, (
B) is a case of multivariable control according to the present invention. Figure 8 G4
) (Zi') is the transient response when the clutch is disengaged (disconnected at the tO point), (A is the conventional method, (B) is the method of the invention of the present invention. When the air conditioner is fully turned on and the target idle rotation speed k shifts to 800 rpm, ν and the air conditioner is turned off and the target idle rotation speed f returns to 650 rpm. Conventional method (D is the case of the method of the present invention. Figure 10 (4) and (13) are for the no-load high rotation state force/
All transient responses are shown when coasting to the target value of 650 t'pm. (, 4) is for the conventional method, and C&) is for the method of the present invention. Figure 7 (,4) (rib or first
As is clear from FIG. 0(,1)<11), in all cases, the method according to the present invention improves the transient controllability by one degree. Note that in FIG. 7 (Idle rotation speed is not skewed to the target value).

Figure 11 G4) (a B and Figure 12 (3) (phrase is
In the case where unpredictable air disturbance is added, the 11th
Figure ((9) (D) shows the idle rotation speed, air volume, and ignition timing at startup, and Figure 12 ((4) (weak) shows the idle rotation speed, air volume, and ignition timing when the foot is on the accelerator. The movement (when the accelerator is completely released at time to) is shown in Figure 7, respectively, (4) is the conventional method, and ■ is the method of the present invention.As is clear from the figure, in both cases, the present invention It can be seen that by using the method shown in FIG.

As mentioned above, when the idle rotational speed of the internal combustion engine according to the present invention is set to j#, the control input is:
Any one or a combination of two or more selected from air amount (or equivalent amount), ignition timing, fuel supply amount (or equivalent amount)2, and exhaust recirculation amount (or equivalent amount). In the above embodiments, the pulse width of the VCM valve control solenoid and the ignition IJ are equivalent to the bypass air per control input and the total control input for the pigeon house.

(Effects of the Invention) As explained above, according to the present invention, the idle rotation speed is controlled by applying all the multivariable control methods based on the dynamic model of the internal combustion engine, and the dynamic state r of the internal combustion engine is estimated. By adding all steps and reducing the dimensionality of the engine model in the state observer, we reduced the calculation time completely, and the approximation error was absorbed by integration and operation, so the problem did not occur in the idle state. The control transient response to disturbances such as misfire disturbances and load disturbances can be optimized, and it is also easy to control by adding multivariable control inputs to increase the degree of control freedom and improve controllability, resulting in more stable idle rotation. The effect of realizing speed control can be obtained.

In particular, due to unpredicted air samurai and corpse disturbance, the actual value N of the idle rotation speed exceeds the target value N, 7.
If the disturbance is suddenly removed, the state variable txi representing the dynamic internal state of the engine becomes initially 1.
At the same time as canceling the straight line, dimension, and integral fold,
Air A [which is the control force] should be increased, and the ignition timing should also be advanced to the advanced side. , it is possible to achieve the effect of realizing more stable idling operation.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional idle rotation speed control device for an internal combustion engine, Fig. 2 is a flowchart showing a conventional idle rotation speed control method, and Fig. 3 is a diagram of an internal combustion engine according to the present invention. Figure 4 is a block diagram showing the relationship between the control input/output and engine in Figure 3, and Figure 5 is a block diagram of the integral + gain block in Figure 3. Details are not shown. Figure 6 is a flowchart fully explaining one method of use according to the present invention. Figure 7 (, 4) (13)
Figure 8 shows the experimental results of the transient response when the clutch is engaged.
Figure (4)) is a diagram showing all the experimental results of the transient response when the clutch is engaged, Figure 9 (4) (n is a diagram showing the experimental results of the transient response when the air conditioner is turned on and off, and Figure 10 (A) shows the experimental results of the transient response during coasting, Figure 11 (A) shows the experimental results of the transient response during engine startup, and Figure 12 (A) (B) 2 is a diagram showing the experimental results of the transient response when the accelerator is suddenly released while the foot is on the accelerator.■...AAC valve, 2...VCM valve,
3...Control solenoid, 4...Throttle valve, 5...Bypass, 7...Throttle valve switch, 8...Neutral switch, 1o・
... Water temperature sensor, 11 ... Air conditioner switch, 12 ... Internal combustion engine (controlled object), 13 ... Status - side unit, 14゛ ... Integral operation and gain block, Nr
...Target 1st shift of idle rotation speed, N...Actual source of idle rotation speed, Na...Standard setting value of idle rotation speed, SA...
・Difference between target 1@ and actual value of idle rotation speed, PA
... Drive bypass width of the control solenoid that specifies the total amount of bypass air, IT ... Ignition timing, Publication ... State variable before, B ... Amount of bad variable in the previous side control cycle, Publication ...・Introduction of state variables. Izumi 2 figure L3 290- recruitment Δ figure I4 0,,L,,. 1-, J

Claims (1)

[Claims] Target 11 of idle rotation speed when the internal combustion engine is idle
戊N? , and based on the deviation SA of the actual 1st N, the idle rotation speed is feedback-controlled. Based on the dynamometer of the internal combustion engine that is assigned to the controller, Input 1: The amount of air supplied to the internal combustion engine or the amount of air corresponding to the amount of air 2, the 7 ignition timing j=' of the first row of the internal combustion engine, and the amount of air supplied to the internal combustion engine. Natural materials and common materials are the fuel supply,
The amount of children's return or money equivalent to Fukuen
Any 1″ selected from the children corresponding to the amount of care:)
Or a combination of two or more and the internal combustion? Substituting the dynamic internal state of the internal combustion engine from the idle rotational speed of tlJ, one output, one shift, and the state transformation of the appropriate order x? , (Z-1+2+...n), and the state of the estimated formula is the prize X (♂=1.2.
The control input 11M is determined from the integral of the deviation SA of the rotational speed and the constant disturbance J,! When the deviation SA continues to occur and the continuous disturbance is eliminated, the idle rotational speed of an internal combustion engine characterized by a milli-cooling input, one surface input, and one direct force is applied so as to reduce the large fluctuation in the rotational speed by one step. j your way.