JP2745797B2 - Idling speed controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idling speed control apparatus for an internal combustion engine, and more particularly, to compensating for a waste time from a time when an operation amount is operated to a time when a speed changes, and a disturbance. The present invention relates to an idling rotation speed control device capable of suppressing fluctuations in the idling rotation speed even when is applied.

[Prior Art] As a device for controlling the idling rotational speed of an internal combustion engine, the rotational speed of the internal combustion engine is detected, and a well-known PID calculation is performed on a deviation from a target idling rotational speed. The controls are well known.

However, in this device, the responsiveness is not sufficient. For example, when disturbance is applied, such as when the air conditioner is turned on, or when the power steering pump is operated, the idling speed greatly fluctuates. There was a problem to do.

In order to solve this problem, a model representing the dynamic behavior of the internal combustion engine was constructed from a transfer function that inputs an operation amount that can control the number of revolutions and outputs the number of revolutions, and was designed using this model. A system in which the idling speed is controlled by an optimum regulator has been proposed (JP-A-59-4635).
3).

However, in an actual internal combustion engine, there is a waste time due to air and fuel transfer delay between the time when the operation input is operated and the time when the rotation speed of the internal combustion engine changes, but it was constructed from the transfer function. Since the model does not consider this waste time, there is a problem that the rotation speed hunts when the gain of the optimum regulator increases.

In order to solve this problem, there has been proposed a system in which the idling speed is controlled by an optimal regulator designed using a model taking into account the waste time existing during operation input (Japanese Patent Laid-Open No. 64-64). 8336).

[Problems to be Solved by the Invention] However, in these methods, although the intake air amount is selected as the operation input, the waste time from the operation of the intake air amount to the change in the rotation speed is relatively large. The ability to maintain a constant idling speed deteriorates.

Further, in these methods, since disturbance is compensated by feedback control, there is a problem that the idling speed greatly fluctuates when the air conditioner operates or when the power steering pump operates.

Accordingly, the present invention has been made in view of the above problems, and maintains the idling rotation speed accurately and constant by selecting at least one operation input with a small waste time, and feed-forwards the operation input with respect to disturbance. It is an object of the present invention to provide an idling speed control device for an internal combustion engine that operates to reduce fluctuations in the idling speed when a disturbance is applied.

[Means for Solving the Problems] FIG. 1 shows a basic configuration of an idling control device for an internal combustion engine according to the present invention.

That is, the present apparatus includes: a rotation speed storage unit A that reads the rotation speed of the internal combustion engine at each predetermined sampling timing and stores a read value of the rotation speed of the past predetermined number of sampling times;
At least one operation amount storage means B1 for reading at least one operation amount capable of operating the rotation speed of the internal combustion engine in synchronization with the reading of the rotation speed and storing a read value of at least one operation amount for a predetermined number of samplings in the past; B2, ...
BL and a linear combination value of the number of revolutions of the predetermined number of past samplings stored in the number-of-rotations storage means A and at least one of the predetermined number of past samplings stored in at least one operation amount storage means B1, B2,. Waste time compensating means C for compensating the rotational speed of the internal combustion engine and the waste time of at least one manipulated variable based on the sum of the linear combination value of one manipulated variable and the waste time compensating means C; The number of rotations and at least one manipulated variable storage means B1, B2,...
A linear combination for calculating at least one current operation amount based on at least one operation amount of the past predetermined number of samplings stored in BL, the number of rotations whose waste time has been compensated by the waste time compensating means C, and at least one operation amount; Calculating means D for determining at least one equivalent compensation value for at least one disturbance causing a change in the rotational speed of the internal combustion engine;
And a disturbance compensating means E for adding to one operation amount.

[Operation] In the idling control device for an internal combustion engine configured as described above, the waste time of the operation input is compensated by the predicted value calculation means, and the operation input is determined by the optimal regulator having the compensation value as the input. At the same time, the compensation value is added to the operation input by the disturbance compensating means so as to suppress the fluctuation of the rotation speed due to the disturbance, so that the fluctuation of the idling rotation speed is suppressed to a minimum.

[Embodiment] Fig. 2 is a configuration diagram of one embodiment of an idling speed control device for an internal combustion engine according to the present invention, and an operation input is an idling speed control valve (hereinafter referred to as an ISC valve).
Two values are used: the air flow rate adjusted by the opening and the ignition timing of the ignition plug.

Further, two disturbances, an air conditioner and a power steering pump, are taken into consideration as disturbances.

(1) Configuration of the embodiment In FIG. 2, the internal combustion engine comprises a cylinder block 1, a cylinder head 2 and a piston 3, and a combustion chamber 4
Is defined by being surrounded by these.

An intake port 5 for guiding intake air to the combustion chamber 4 and an exhaust port 6 for exhausting combustion gas are provided in the cylinder head 2.
Are formed, and an intake valve 7 and an exhaust valve 8 are installed in each of them.

An intake pipe 10 for guiding air sucked from an air cleaner 9 is connected to the intake port 5. A throttle valve 12 driven by depressing an accelerator pedal 11 and a throttle valve 12 in the intake pipe 10 are provided between the intake pipes 10. A surge tank 13 for suppressing intake surging is provided.

An ignition plug 14 is attached to the cylinder head 2 and is ignited based on an ignition command from a distributor 15 to explode an air-fuel mixture in the combustion chamber 4.

The distributor 15 is provided with a crank angle sensor 16 that outputs a pulse every 720 °, for example, in terms of a crank angle, and a crank angle sensor 17 that outputs a pulse every 30 °.

Outputs of the crank angle sensors 16 and 17 are supplied to an input / output interface 102 of the control circuit 100 as a rotation speed signal of the internal combustion engine.

Further, an injector 18 is provided near the intake port 5 to supply the fuel to each combustion chamber 4 based on a command from the control circuit 100 for fuel.

A bypass passage 19 connecting the intake pipe 10 upstream and downstream of the throttle valve 12 is provided, and an ISC valve 20 whose opening is controlled by a pulse signal output from the control circuit 100 in the middle of the bypass passage 19. Is installed.

The control circuit 100 is configured by, for example, a microcomputer system, and includes an A / D converter 101, an input / output interface 102, a CPU 103, a ROM 104, a RAM 105, a backup memory 106, a clock generation circuit 107, and the like.

(2) Design of idling rotation speed control device In order to configure an idling rotation speed control device having excellent control performance, the following three points must be considered.

i) Since the ignition timing and the ISC valve opening are selected as the operation inputs, it is possible to realize highly accurate control with excellent responsiveness. However, if the two operation inputs are not properly operated. On the contrary, the fluctuation of the idling rotational speed increases.

ii) It takes 1
From 2 operation cycles, and 5 after operating the ISC valve opening
There is a waste time of 6 operation cycles from. If the control is executed ignoring this waste time, the idling speed will be hunting and not stable.

iii) When a disturbance load such as an air conditioner or a power steering pump is turned on / off, the idling speed fluctuates. However, in order to prevent a so-called engine stop, it is necessary to suppress this fluctuation as much as possible.

In order to realize an idling speed control device that satisfies the above three points at the same time, a control device is designed by applying modern control theory. I) Use an optimal regulator to determine a control law for properly operating the two operation inputs.

In order to design an optimal regulator, a dynamic characteristic model based on the display of state variables of the internal combustion engine is required. As this model, an ARMA model that estimates parameters included in the model from dynamic characteristic data of the internal combustion engine is used.

ii) Since each of the two operation inputs has a waste time, the optimum control rule for the past operation input is determined depending on the optimum regulator, and the current operation input is not determined.

To solve this problem, waste time compensation is performed by the state variable estimating means.

iii) The compensation means is incorporated in the control device in consideration of the application of disturbance.

 Hereinafter, a method of designing the control device will be described step by step.

1) Construction of ARMA model considering waste time and disturbance N (k) The actual sampling value of the ISC valve opening is uc (k) The actual sampling value of the ignition timing is up (k) However, if k is an index representing a sampling timing (sampling may be performed at a predetermined time cycle or at a predetermined crank angle cycle), the dynamic characteristic of the rotation speed of the internal combustion engine is obtained. It can be modeled as follows:

N (k) = a ₁ · N (k−1) + a ₂ · N (k−2) + b _c1 · u _c (k−d _c −1) + b _c2 · u _c (k−d _c −2) + b _{p1 · u p (k-d} p -1) + b p2 · u p (k-d p -2) + e a + w a + e s · w s (1) where, after operating the d _c = ISC valve Waste time realized by sampling system until rotation speed changes d _p = Waste time expressed by sampling system from ignition timing operation to rotation speed change e _a = Rotation speed fluctuation due to air conditioner on / off Gain e _s = rotation speed fluctuation gain due to turning on / off of the power steering pump w _a = air conditioner load w _s = power steering pump load The model using the values up to two sampling cycles before is shown here. It is possible to use the sampled values to improve the accuracy of the model.

If put Here, for simplicity _{u c (k-d c)} = v c (k) u p (k-d p) = v p (k) (2), (1) equation N (k ) = A ₁ · N (k−1) + a ₂ · N (k−2) + b _c1 · v _c1 (k−1) + b _c2 · v _c (k−2) + b _p1 · v _p (k−1) _{+ b p2 · v p (k} -2) + e a · w a + e s · w s (3) and can be written.

2) Construction of state variable display model If equation (3) is expressed as an observable standard form state variable, X (k + 1) = Φ · K (k) + Γ · V (k) = E · W (4) where Here, Θ = [0, 1].

3) Estimation of state variables From equation (5), X ₂ (k + 1) = N (k) (6) From equation (4), x ₂ (k + 1) = x ₁ (k) + a ₁ · x ₂ (k) + b _{c1 · v c (k) +} b p1 · vp (k) + e a · w a + e s · w s (7) x 1 (k + 1) a 2 · x 2 (k) + b c2 · v c (k) + b p2 _{· v p (k) (8} ) (6) expression and (8) x ₁ (k) from the equation _{= a 2 · N (k-} 1) + b c2 · v c (k-1) + b p2 · v p ( k-1) (9) (6) below, (7) and (9) from the _{x 2 (k) = x 1} (k-1) + a 1 · N (k-1) + b c1 · v c ( _{k-1) + b p1 ·} v p (k-1) e a · w a + e s · w s = a 2 · N (k-2) + b c2 · V c (k-2) b p2 · v p ( _{k-2) + a 1 ·} N (k-1) + b c1 · V c (k-1) + b p1 · v p (k-1) + e a · w a + e s · w s = a 2 · N (k _{-2) + a 1 · N (} k-1) + b c1 · v c (k-1) + b c2 · v c ( _{k-2) + b p1 ·} v p (k-1) + b p2 · v p (k-2) + e a · w a + e s · w s (10) , and the state variables x ₁ and x ₂ the past 2 times , And the sum of the linear combination of the sampling values of the two inputs.

4) Design of control system In equations (4) and (5), if there is Xr and Vr where N (k) = Nr (constant value) (11), then from equation (4), Xr = Φ Xr + Γ · Vr + E · W (12) Nr = Θ · Xr (13) Equations (12) and (13) are regarded as equations for Xr and Vr, and if a solution can be obtained, then N ( k) exists.

When rearranging equations (12) and (13) for Xr and Vr, However, the left side coefficient matrix of the equation (14) is a (3 × 4) matrix, is not square, and cannot uniquely determine Xr and Vr.

 Therefore, for example, a virtual target value Cr is given as in the following equation.

h ₁ · v _cr + h ₂ · v _pr = Cr (15) Here, Cr may be a constant or a function such as a rotation speed.

And the left side coefficient matrix becomes a square matrix of (4 × 4),
Xr, v _cr , and v _pr can be solved.

In the equation (15), for example, h ₁ = 1, h ₂ = −2, Cr = 0
This means that when v _cr changes by 1, v _pr changes by 1/2. In other words, it indicates that v _cr performs control with twice the magnitude.

Since the coefficient and Cr in Equation (15) can be determined artificially, the gain is large for operation inputs that can be operated quickly and large and the waste time is short, and conversely, the operation width is small and operation is slow. Can reflect a constraint condition on an operation input when designing a control device, such as setting a small gain.

(16) by solving the equation, constant matrix F ₁₂ of _{Xr = F 11 · E · W} + F 12 · Nr Vr = F 21 · E · W + F 22 · Nr (17) but F ₁₁ is (2 × 2) is (2 The (× 1) constant matrix F ₂₁ can be expressed as a (2 × 2) constant matrix F ₂₂ .

Next, by subtracting equation (12) from equation (4) and equation (13) from equation (5), [X (k + 1) −Xr] = Φ · [X (k) + Xr] + Γ · [V (k ) −Vr] (18) [N (k) −Nr] = Θ · [X (k) −Xr] (19) where δX (k + 1) = X (k + 1) −Xr δX (k) = X (k ) −Xr δV (k) = V (k) −Vr δN (k) = N (k) −Nr (20) Equations (18) and (19) yield δX (k + 1) = Φ · δX (k) + Γ · δV (k) (2
1) δN (k) = Θ · δX (k) (22) When an optimal regulator is designed for the system represented by the equations (21) and (22), the optimal control law is determined by the following equation. .

δV (k) = K · δX (k) (23) where K is a (2 × 2) gain matrix determined from the well-known Riccati equation.

From equation (23) and equation (20), V (k) = K ・ X (k) −K ・ Xr + Vr (24) By substituting equation (17), V (k) = K ・ X (k) −K _{· F 11 · E · W-} K · F 12 · Nr + F 21 · E · W + F 22 · Nr = K · X (k) + K w · W + K N · Nr However _{K w = F 21 · E-} K · F 11 _{· E K N = F 22 -K} · F 12 (25) _{Thus, v c (k) = k} 11 · x 1 (k) + k 12 · x 2 (k) + k wa1 · w a + k ws1 · w s k _{N1 · Nr (26) v p} (k) = k 21 · x 1 (k) + k 22 · x 2 (k) + k wa2 · w a + k ws2 · w s + k N2 · Nr (27) (26) and equation (27) the use of equations (9) and _{(10), v c (k) = a} 1 '· N (k-1) + a 2' · N (k-2) + b c1 '· v c _{(k-1) + b c2} '· vc (k-2) = b P1' · v P (k-1) + b P2 '· v P (k-2) + kw a1 · w a + kw s1 · w s + k N1 Nr (28) vp (k) = a ₁ "N (k-1) + _{a 2 "· N (k-} 2) + b C1" · v c (k-1) + b c2 "· v c (k-2) + b p1" · v p (k-1) = b p2 "· v p (k-2) + k is expressed as _{wa2 · w a + k ws2 ·} w s + k N2 · Nr (29).

5) Using the dead time compensation where the (2) equation u _c (k), when obtaining the _{u p (k), u c} (k) = v c (k + d c) = a 1 '· N (k + d _{c -1) a 2 '· N} (k + d c -2) + b c1' · u c (k-1) + b c2 '· u c (k-2) + b p1' · u p (k-1) + b p2 _{'· u p (k-2} ) + k wa1 · w a + k ws1 · w s + k N1 · Nr (30) u p (k) = v p (k + d p) = a 1 "· N (k + d p -1) _{+ a 2 "· N (k} + d p -2) + b c1" · u c (k-1) + b c2 "· u c (k-2) + b p1" · u p (k-1) + b p2 "· u p _{(k-2) + k wa2} · w a + k ws2 · w s + k N2 · Nr (31) where N (k + dc-1) , N (k + dp-1) but the value of such a need, it is the future Since it is a value, it cannot be directly obtained from the sampling value of the rotation speed.

 Here, equation (1) is rewritten as the following equation.

_{N (k) = A 11 ·} N (k-1) + A 12 · N (K-2) + B C11 · u C (k-d C -1) + B C12 · u C (k-d C -2) + B _P11 · u _P (k−d _P −1) + B _P12 · u _P (k−d _P −2) + C _a1 · W _a + C _s1 · w _s (32) where A ₁₁ = a ₁ A ₁₂ = a ₂ B _{By setting c11} = b _c1 B _c12 = b _c2 B _p11 = b _p1 B _p12 = b _p2 C _a1 = e _a C _s1 = e _s k = k + 1, N (k + 1) = A ₁₁ · N (k) + A _{12 · N (k-1)} + B c11 · u c (k-d c) + B c12 · u c (k-d c -1) + B p11 · u p (k-d p) + B p12 · u p (k _{-d p -1) + C a1 ·} w a + C s1 · w s = A 11 · [A 11 · N (k-1) + A 12 · N (k-2) + B c11 · u c (k-d c - _{1) + B c12 · u c} (k-d c -2) + B p11 · u p (k-d p -1) + B p12 · u p (k-d p -2) + C a1 · w a + C s1 · w _{s] + A 12 · N (} k-1) + B c11 · [a 1 '· N (k-1) + a 2' · N ( _{-2) + b c1 '· u} c (k-d c -1) + b c2' · u c (k-d c -2) + b p1 '· u p (k-d p -1) + b p2' · u _{p (k-d p -2)} + k wa1 · w a + k ws1 · w s + k N1 · Nr] + B C12 · u c (k-d c -1) + B P11 · [a 1 "· N (k-1 ) + A ₂ ″ · N (k−2) + b _C1 ″ · u _c (k−d _c −1) + b _C2 ″ · u _c (k−d _c −2) + b _P1 ″ · u _P (k−d _{P) -1) + b P2 "· u} P (k-d P -2) + k wa2 · w a + k ws2 · W s + k N2 · Nr] + B P12 · u P (k-d P -1) + C a1 · w a + C _s1 · w _s = [A ₁₁ · A ₁₁ + A ₁₂ + Bc ₁₁ · a ₁ ′ + B _p11 · a ₁ ″] · N (k−1) + [A ₁₁ · A ₁₂ + Bc ₁₁ · a ₂ ′ + B _p11 · a ₂ ″] · N (k−2) + [A ₁₁ · B _c11 + B _c11 · b _c1 ′ + B _p11 · b _c1 ″ + B _c12 ] · u _c (k−d _c −1) + [A ₁₁ · B _{c12 + B c11 · b c2 '} + B p11 · b c2 "J · u c (k-d c -2) + [A 11 · B p11 + B p11 · _{b p1 '+ B c11 · b} p1 "+ B p12] · u p (k-d p -1) + [A 11 · B p12 + B c11 · b p2' + B p11 · b p1" J · u c (k-d _{p -2) + [(A 11} +1) · C a1 + Bc 11 · k wa1 + B p11 · k wa2] · w a + [(A 11 +1) · C s1 + Bc 11 · k ws1 + B p11 · k ws2] · w _s = A ₂₁ · N (k−1) + A ₂₂ · N (k−2) + B _c21 · u _c (k−d _c −1) + B _c22 · u _c (k−d _c− 2) + B _p21 · _{u p (k-d p -1} ) + B p22 · u p (k-d p -2) + C a2 · w a + C s2 · w s + (B c11 · K N1 + B P11 · K N2) · Nr (33 ) where _{A 21 = A 11 · A 11} + A 12 + B C11 · a 1 '+ B P11 · a 1 "A 22 = A 11 · A 12 + B C11 · a 2' + B P11 · a 2" B c21 = A 11 · B _c11 + B _c11 · b _c1 ′ + B _p11 · b _c1 ″ + B _c12 B _c22 = A ₁₁ · B _c12 + B _c11 · b _c2 ′ + B _p11 · b _c2 ″ B _p21 = A ₁₁ · B _p11 + B _p11 · b _p1 ′ + B _c11 · b _p1 ″ + B _p12 B _p22 = A ₁₁ · B _p12 + B _c11 · b _p2 ″ + B _p11 · b _p1 ′ C _{a2 = (A 11 +1) ·} C a1 + B c11 · k wa1 + B p11 · b wa2 C s2 = (A 11 +1) · C s1 + B c11 · k ws1 + B p11 · k ws2 following Similarly N (k + i) is also N (k-1), N (k-2) u c (k-d e -1), u c (k-d c -2) u p (k-d p -1), u p (k- d _p -2) can be written as the sum of w _a , w _s , and Nr.

That is, the value of the rotation speed after the waste time compensation is performed can be represented by a linear combination of the rotation speed and the history value of the operation input.

By substituting these into equations (30) and (31), the following equation can be obtained.

u _c (k) = γ ₁₁ · N (k−1) + γ ₁₂ · N (k−2) + ζ _c11 · u _c (k−d _c −1) + ζ _c12 · u _c (k−d _c −2) _{+ ζ p11 · u p (k} -d p -1) + ζ p12 · u p (k-d p -2) + κ 1a · w a + κ 1s · w s (k) + κ 1N · Nr (34) u P (k _{) = γ 21 · N (k} -1) + γ 22 · N (k-2) + ζ C21 · u C (k-d C -1) + ζ C22 · u C (k-d C -2) + ζ P21 · u based on the _{P (k-d P -1)} + ζ P22 · u P (k-d P -2) + κ 2a · w a + κ 2s · w s + κ 2N · Nr (35) (3) description of the above execution of the control FIG. 3 shows a functional diagram of the idling speed control device configured as described above.

This figure is a diagram showing a functional configuration of the idling speed control device.
The processing is executed by the control circuit 100 centered on 3.

The rotation speed N of the internal combustion engine 1 is obtained by counting the pulses output from the crank angle sensors 16 and 17 attached to the distributor 15, and is stored in the first shift register 300 in the RAM 105 for two samplings. .

The ignition timing and u _P opening u _C and the spark plug 14 of the ISC valve 20 provided in the bypass passage 19 of the operation input in which the intake pipe 13 to operate the rotation speed N of the internal combustion engine 1, in the control circuit 100 Are stored in the second and third shift registers 310 and 320 in the RAM 105 for (d _c +2) and (d _p +2) samples, respectively.

The load w _a when the air conditioner is activated, the load w _s when the power steering pump is activated, and the set value Nr of the idling speed are set in the setting unit 33 in the ROM 104.
0, 340 and 350.

These values are calculated according to the equations (34) and (35) as 301 to 304, 311 to 314, 321 to 324, 331 and 332, 341 and 342.
And after being multiplied by 351 and 352, 305 to 308, 31
Linear combination is performed at 5 to 318, 325 to 328, 335 and 336 and 345 and 346, and a new operation input is calculated.

FIG. 4 is a diagram showing a control calculation routine for executing the above-described control calculation, which is executed, for example, at every 60 ° crank angle.

First, at step 401, the rotational speed N of the internal combustion engine is read.

Next, in steps 402 and 405, it is determined whether or not the air conditioner and the power steering pump are on.
w _a and w _s are set to predetermined values w _as and w _ss .

They w _a and w _s in steps 404 and 407 when off is reset to "0".

Subsequently dead time compensation computation with respect to the rotational speed N by in step 408 (33) equation, dead time compensation operation is performed with respect to the operation input u _c and u _p by in step 409 (28) and (29) below.

In steps 410 and 411, equation (34) and (35)
Operation input based on the equation u _c (k) and u _p (k) is calculated,
Then, disturbance compensation is performed, and these calculation results are output in step 412.

Then, in step 413, the value of the shift register provided in the RAM is shifted by one to prepare for the next operation.

In the present embodiment, the ISC valve opening and the ignition timing of the spark plug are used as operation inputs for the rotation speed of the internal combustion engine, but other operation inputs, for example, the idling rotation speed can be reduced by adding or adding the fuel injection amount. It is also possible to control.

Further, it is also possible to compensate for a lamp lighting, a clutch meet in a manual transmission vehicle, and the like as disturbances.

Further, since the waste time compensation and the disturbance compensation are realized by a linear combination operation, the size of a program incorporated in the control circuit can be reduced, and an economic effect can be obtained.

[Effects of the Invention] As described above, according to the present invention, the operation input is determined by the optimal regulator that receives the compensation value whose waste time has been compensated by the predicted value calculation means, and the operation input is determined by the disturbance compensation means. , The fluctuation of the idling speed is suppressed to a minimum, and the so-called engine stop resistance is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an idling speed control device according to the present invention, FIG. 2 is a configuration diagram of one embodiment, FIG. 3 is a functional diagram of the embodiment, and FIG. It is a flowchart which shows. A: rotation speed storage means, B: operation input storage means, C: waste time compensation means, D: linear coupling operation means, E: disturbance compensation means.

Claims (1)

(57) [Claims] A rotational speed storage means for reading a rotational speed of an internal combustion engine at a predetermined sampling timing and storing a read value of a rotational speed of a predetermined predetermined number of sampling times in the past.
And reading at least one operation amount capable of operating the rotation speed of the internal combustion engine in synchronization with the reading of the rotation speed, and storing a read value of at least one operation amount of a predetermined number of times of sampling in the past. Operation amount storage means (B
1, B2,... BL), a linear combination value of the number of rotations of the past predetermined number of samplings stored in the number-of-rotations storage means (A), and the at least one manipulated variable storage means (B1, B2,. ··· BL) and the rotational speed of the internal combustion engine and at least 1
A waste time compensating means (C) for compensating wasteful time for two operation amounts; a rotation speed of a predetermined number of past samplings stored in the rotation speed storage means (A); and at least one operation amount storage means (B1, B2,... BL), at least one operation amount of the past predetermined number of samplings, the rotation speed and the at least one operation amount of which the waste time has been compensated by the waste time compensating means (C). Linear combination operation means (D) for calculating at least one operation amount; and disturbance compensation means (E) for adding an equivalent compensation value for at least one disturbance that causes a change in the rotation speed of the internal combustion engine to at least one operation amount. ), An idling speed control device for an internal combustion engine.