JPS62279248A - Idling engine speed control device - Google Patents

Abstract

PURPOSE:To reduce the feedback controlling time of engine speed and improve controllability by providing an estimated controlling quantity determining means for determining an estimated controlling quantity from a correcting controlling quantity and a fundamental estimated controlling quantity. CONSTITUTION: A fundamental estimated controlling quantity is operated 33 by receiving the output of a target engine speed setting means 31. A correcting controlling quantity is operated 36 by receiving the output of an estimated controlling quantity result judging means 34. An estimated controlling quantity determining means 37 receives the outputs of the operating means 33, 36 and determines an estimated controlling quantity. Thus, since the optimum value of a load estimated controlling quantity can be obtained, the controlling time of engine speed can be reduced while increasing the responsiveness of control.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an idle rotation speed control device for an internal combustion engine used in automatic engines and the like.

[Conventional technology]

In automobiles, fuel consumption is reduced during idle by comparing the engine speed at idle with the target idle speed and controlling the engine speed to the target speed by changing the throttle valve opening according to the deviation. Some vehicles are equipped with an idle speed control device designed to achieve this.

Fig. 2 shows a conventional idle speed control device, in which 1 is a piston, 2 is a cylinder, 3 is an intake valve, 4 is an exhaust valve, 5 is an exhaust pipe, 6 is a three-way catalytic converter, 7 is an intake pipe, 8 is the throttle valve, throttle valve 8): flow fill
K is provided with a venturi 9 and an air cleaner 10,
The fuel in the float chamber 1) is sucked in through the main fuel passage 12 when the intake air that has been fully taken in through the air cleaner 10 passes through the venturi 9 and is atomized. and is guided into the cylinder 2 via the intake pipe 7.

In this case, a main air bleed 13 is provided in the middle of the main fuel passage 12, and the fuel in the float chamber 1) is transferred to the main air bleed passage 13 provided on the upstream side of the venturi 9.
It is atomized after being atomized by the intake air from the air.

On the other hand, an idle boat 15 is placed on the lower side of the throttle valve 8.
A slow air bleed passage 16 is provided on the J: downstream side of the venturi 9, and the fuel in the main fuel passage 12 is atomized in the slow air bleed 17 by the intake air from this slow air bleed passage 16. It is discharged from the idle port 15. As a result, fuel is secured during idling when the throttle valve 8 is approximately fully closed. In this case, the fuel discharged from the idle port) 15 is
It is adjusted accordingly.

Here, the throttle valve 8 is an accelerator pedal (not shown)
While driving, the opening degree corresponds to the amount of depression of the accelerator pedal, and when the accelerator pedal is released and the vehicle is idling, the opening degree is the degree necessary to maintain the idling state. Further, this throttle valve 8 is provided with a <-19 on its rotation axis, and by driving this lever 19 with an actuator 20, the opening degree during idling can be varied.

Next, the configuration of the idle rotation speed control system will be explained.

20 consists of a DC motor 21 and a gear mechanism 22), the gear mechanism 22 converts the rotational movement of the DC motor 210 into a linear movement of the jigranger 23, and this linear movement causes the lever 1 to move.
The DC motor 21 is supplied with an old rotation control pulse U and a reverse rotation control pulse D having a predetermined pulse width from a control circuit 30. In this case, an idle state detection switch 24 is provided in the actuator 20, which is turned on (closed) when the tip of the ground gloss 23 is in contact with the lever 19, that is, when the accelerator pedal is released and the vehicle is idle. 2
Reference numeral 5 denotes a rotational speed detector for detecting the engine rotational speed, and here a rotational pulse signal having a period corresponding to the engine rotational speed N is taken out from a connection point between the ignition coil 26 and the interrupter 27.

Reference numeral 28 indicates an operation start switch (hereinafter abbreviated as A/C-SW) of a sudden air conditioner, which is one of the engine loads, and 29 indicates that the transmission (not shown) is in the neutral position or the clutch (not shown) is activated. This is a gear change switch that detects that the engine wheel is turned on (depressed), that is, that the engine wheel is disconnected. Also, based on the output signals of the 30μ idle switch 24, rotation speed detector 25, A/C-8W 28, and speed change switch 29, the opening degree of the throttle valve 8 during idle is controlled to converge the engine rotation speed to the target rotation speed No. This is a control circuit that performs control. As shown in FIG. 3, the control circuit 30 includes an arithmetic processing unit (hereinafter abbreviated as CPU) 300 and a only memory (hereinafter abbreviated as ROM) that stores programs, constants, etc. for controlling the idle rotation speed. )30
1, a random access memory (hereinafter abbreviated as RAM) 302 for storing intermediate results, etc., and an interface circuit (hereinafter abbreviated as IFC) 303 for signal transmission and reception.

Next, the operation of the above configuration will be explained using the flowcharts of FIGS. 4 and 5. First, when the engine is started,
Processing as shown in FIG. 4 is executed according to programs stored in the CPU 300 and ROM 301. That is,
In step 100, the CPU 300 takes in the output signal from the rotation detector 25, and detects the current engine rotation speed N by measuring the period of the signal. In step 102,
The CPU 300 calculates the target rotation speed No. during idling. The target rotational speed No. differs depending on whether the air conditioner is in an operating state or in a non-operating state, and is determined, for example, as shown in Table 1.

Table 1 This idle target rotation speed No. is stored in advance in the ROM 301 as a constant. Therefore, calculation of the idle target rotation speed No. is realized by reading the above constant from the ROM 301'D''.Next, in step 103, the CPU 300 determines whether the engine rotation speed N is 40 ORPM or more. , if the engine speed is less than 400 RPM, it is determined that the engine is before a complete explosion, and in step f1)7, the drive mode of the actuator 20 is set to the hold mode, and no idle speed control is performed on the actuator 20. However, if the engine speed is below 400 RPM, In this case, it is determined that the engine has completely exploded, and in step 104 it is determined whether the gear change switch 29 is on or not (whether the gearbox is in the neutral position or whether the clutch is open/closed). Then, in step 105, it is determined whether the idle switch 24 is on or not.As a result, if the shift switch 29 is on, it is determined that the vehicle is in a running state, and in step 1)7, the single-motion mode is set to the hold mode, Even when the gear shift switch 29 is off, it is assumed that the accelerator pedal is being operated by the driver when the idle switch 24 is off, and in step 1) 7, the drive mode is set to hold mode, and either In this case, idle rotation speed control for the actuator 20 is not executed.

However, when the speed change switch 29 is off (in the neutral state or clutch off state) and the idle switch 24 is on, the engine is in a two-burner idle state where the main fuel is supplied from the idle boat 15. Then, in step 106, it is determined whether the A/C 5W 28 has changed from on to off or from off to on. As a result, if there is no change in the state of the A/C-8W28, the deviation (absolute value) between the idle target rotation speed No. and the current engine rotation speed N is determined in step 107, and this deviation is compared to the predetermined value △ND. It is determined whether the angle is large or not, and if it is small, the drive mode of the actuator 20 is set to the hold mode in step 1)7. However, if the deviation is larger than ΔND, idle speed control is performed to converge the engine speed N to the target speed No. in Stella f108-1)2.

That is, compare N and NO with Stella 7''108.

If No>N, open the throttle valve 8!
I1), the drive mode of the actuator 20 is set to the opening mode in step 109, and if reverse KNO<N, the opening of the throttle valve 8 is controlled to the closing side in step 1)0. Therefore, the drive mode of the actuator 20 is set to the closing mode. After this, in step 1) 1 the deviation between No and N (No
N) Read the driving time data Pw of the actuator 20 corresponding to the above from the ROM 301. This Pw and (N
o-N), for example, as shown in Figure 6, the deviation (
No-N) or (N-No) increases, PW
It is determined that the relationship increases almost proportionally.

In this way, when the drive time data Pw of the actuator 20 corresponding to the deviation between No and N is obtained, the CPU 30
0 is the forward rotation control pulse D for driving the actuator 20 in the direction corresponding to the drive mode for the time corresponding to Pw in step 1)2.
is generated from the IFC 303. In this case, when the drive mode is on the open side, forward rotation control/Gurus U is generated, and conversely, when the drive mode is on the closing side, reverse rotation control/Gurus D is generated. Due to this.

The throttle valve 8 is set and controlled in a direction corresponding to the target rotational speed NO during idling, so that N converges to No. Thereafter, the CPU 300 repeatedly executes the process from step 100 onwards, and after a certain hold time TH has elapsed, generates a control pulse corresponding to the change in the rotational speed at that time.

Throttle valve 8 corresponding to such a deviation between No and N
The engine speed N is maintained at NoK by the opening degree control, that is, the feedback control.

However, when A/Cφ5W2B changes from on to off and then from off to on, the CPU 300 detects this change in step 106. Also, this change is A/C・5
Step 1)3: Check whether W28 changes from on to off.
If there is a change to the ON state, the drive mode of the actuator 20 is set to the open side drive mode in Stella f1)4, and if it is a change to the OFF state, the drive mode is set to the close side drive mode in step 1)5. Set. In step 1) 6, the rotation speed fluctuation due to an increase or decrease in the engine load due to the start or stop of operation of the air conditioner is anticipated, and drive time data P of the actuator 20 corresponding to this expected load fluctuation is calculated.
WAC is read from the ROM 301 as the expected control amount DPWAC. Thereafter, in step 1) 2, the IFC 303 generates a forward rotation control pulse U or a reverse rotation control pulse D for driving the actuator 20 in a direction corresponding to the drive mode for a time corresponding to PwAc. Thereby, the opening degree of the throttle valve 8 is opened by the opening degree corresponding to the drive time data PwmC when the air conditioner starts operating.

Conversely, when the operation is stopped, the valve is closed by the opening degree corresponding to the data PWAC. After performing such anticipatory control, the CPU 300 causes the idle rotation speed to converge to the target rotation speed NO through feedback control from steps 100 to 1)2.

Further, the pulse drive control process of step 1)2 is configured as shown in the flowchart of FIG. 5, and the actuator 20 is driven after waiting for the completion of a predetermined hold time TH. In other words, Stella f201 has a CPU of 300
detects whether or not a predetermined hold time TH has been completed, and if it has not been completed, steps 100 to 1 in FIG.
Repeat step 2. When the CPU 300 detects completion of the predetermined hold time TH, the CPU 300 determines whether or not it is in the hold mode in step 202, and if the CPU 300 is in the hold mode, it repeatedly executes steps 100 to 1)2. If it is not the hold mode, in step 203 drive time data is set in the timer soster in the RAM 302, and in step 204 the drive mode is set to the open side or the close side. Thereafter, the Stella f205 causes the IFC 303 to start generating a forward rotation control pulse U or a reverse rotation control pulse D corresponding to the drive mode. This control pulse U
Alternatively, it is detected whether the generation time of D has been completed, that is, whether the drive time of the actuator 20 has reached the time corresponding to the drive time data, and when it has reached the time, the generation of control noculus U or D is stopped and step In step 206, a predetermined hold time Tu is set in the timer resistor, in step 207 the drive mode is held, and in step 100
Shift to processing. As a result, when the idle speed is controlled by feedback control, the actuator 20 is intermittently driven by a control pulse having a rest time of a predetermined hold time TH, and the engine speed N is N.

It is converged on.

FIG. 7 shows an example of the control operation when, for example, A/C-5W23 changes from off to on.
) shows the waveforms of the forward rotation control pulse U, (b) shows the waveforms of the reverse rotation control pulse D, (c) shows the waveforms of the A/C-SW 28, and (d) shows the waveforms of the engine rotation speed N.

[Problem that the invention seeks to solve]

However, in the conventional idle speed control device described in J:, the drive time data of the actuator 20 given when the load changes, such as in an air conditioner, is 0. The drive time of the actuator 20 required to obtain a representative amount of load fluctuation is Throttle valve 8 for drive time data is given by
The change in opening is not constant due to variations in the actuator 20, changes over time, effects of temperature, etc. As a result, the difference between the engine speed N obtained from the expected control amount at the time of load change and the target speed No varies, and this If the difference is large, it will take a long time until the target rotational speed NO is stabilized by subsequent feedback control, resulting in poor responsiveness. In addition, the amount of load fluctuation changes due to variations in load and changes over time, which also leads to deterioration in responsiveness.

This invention was made in order to solve the problems mentioned above, and it is an idler that can prevent the deterioration of responsiveness due to the influence of the drive characteristics of the actuator and the secular change in the amount of load change. The purpose is to obtain a rotation speed control device.

[Means for solving problems]

The idle rotation speed control device according to the present invention calculates the estimated rotation speed based on the corrected control amount determined by the deviation between the rotation speed obtained by the estimated control based on the predetermined basic expected control amount and the target rotation speed, and the basic expected control amount. The system is equipped with an expected control amount determining means for determining the control amount.

[For production]

In this invention, when performing predictive control using the predictive control amount before performing feedback control of the idle rotation speed, when the rotation speed after the predictive control is above the target, the next predictive control amount is decreased, and when it is below the target, the predictive control is performed. Increase quantity.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. The configuration of the device is the same as that shown in FIG. 2, and FIG. 1 is a functional block diagram. In FIG. 1, 39 is an air condition detection means, 40 is an Enson rotation speed detection means, 31 is a target rotation speed No. setting means, 32 is a rotation speed deviation detection means for detecting 1NoNI, and 33 is a target rotation speed setting. Means 31
34 is a means for receiving the output of the rotation speed detection means 40 and determining the result of the prospective control; 35 is a means for receiving the output of the rotation speed deviation detection means 32 and calculating the basic tail control amount; means for calculating a numerical feedback control amount, 36
37 is a means for receiving the output of the estimated control result determining means 34 and calculating the corrected control amount; 37 is means for receiving the output of the calculating means 33.36 and determining the estimated control amount; 38 is each means 32.3.
5, 37, and 39 to generate a drive signal for the actuator 20.

Next, the operation of the above configuration will be explained with reference to the flowcharts of FIGS. 8 to 10. The flowchart of FIG. 8 is the conventional flowchart shown in FIG. 4 by inserting step 1)8 for determining prospective control results between step 106 and step 107, and the conventional step 1)6.
The content of step 1) has been changed to create a new step 1)9.

, Next, detailed processing contents of step 1)8 are shown in FIG. Step 1) 8 first after changing A/C-8W28
When this is reached, first in step 301 it is determined whether or not the first feedback Noculus Pw of the prospective control results has been calculated. That is, at this time, the expected control/4-rus PWAC
After a hold time TH after driving the actuator 20, the engine speed is stable. If the calculation has been performed, it is determined in step 31) whether or not the dead zone is the same as the previous one, and if the dead zone is the same as the previous time, it is determined in step 302 whether or not the rotational speed deviation lN0-Nl exceeds a predetermined value N2. The process proceeds to step 303 in order to correct the expected control amount only if the estimated control amount is exceeded. In the case of open side drive in step 303, it is determined in step 304 whether the prospective control result is too large or too small for the target rotation speed No. If No>N, it indicates that the expected control amount was small, and in step 305, a predetermined supplementary E It KCU read from the ROM 301 is added to the stored value of the open side expected control amount correction register CU. Also, N<N
o, in step 306 K is calculated from the stored value of Cu.
Subtract cυ. In addition, in the case of closing side drive, step 30
In step 8, it is determined whether No>N or not, and in Stella f309, correction t KCD is made from the stored value of the closing side expected control amount correction resosta CD.
Subtract it, and if No<N, use Stella f310 to calculate K.
Add CD. Such correction is reflected in the process of step 1)9 at the next load change. Furthermore, CU + C
D is initialized to zero at system startup (generally when power is turned on).

FIG. 10 shows a detailed flowchart of step 1)9. In step 410, the driving direction is determined, and in the case of the open side, in step 41), the value of the opening side expected amount correction resostat CU is added to the basic expected control amount DPWACU. , this value is assumed to be prospective control @PWAC. In the case of the closed side, similar processing is performed in step 412.

By performing the above-described processing, a more accurate prospective control I can be obtained each time the prospective control operation is repeated.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to determine the optimal value of the expected load control amount, so it is possible to correct variations in the load amount and changes over time. Therefore, it is possible to control the rotational speed close to the target rotational speed with one preliminary control, it is possible to shorten the time for rotational speed feedback control after the preliminary control, and it is possible to improve the responsiveness of the control.

[Brief explanation of drawings]

1 and 2 are functional block diagrams and configuration diagrams of the device of this invention, FIG. 3 is a configuration diagram of a control circuit according to the invention, FIGS. 4 and 5 are flowcharts of the conventional device, and FIG. 6 is a diagram of the relationship between the rotation speed deviation and the actuator drive nocellus width according to the present invention, FIG. 7 is the operating waveform blade of the conventional device, and FIGS. 8 to 10 are flowcharts of the device of the present invention. 08...Throttle valve , 20...actuator, 24
... Idle switch, 25 ... Rotation speed detector, 2
8 - A/C-SW, 29... Speed change switch, 30-... Control circuit, 31... Target rotation speed setting means, 32... Rotation speed deviation detection means, 33... Basic expected control amount Calculating means, 34... Expected control result determining means, 3
5... Rotation speed feedback control amount calculation means, 36.
. . . Correction control amount calculating means, 37 . . . Estimated control amount determining means, 38 . . . Drive signal generation means, 39 . . . Idle state detection means, 40 . Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) It has an actuator that varies the throttle opening when the engine is in an idle state, and when the load changes, the actuator is driven by a preset expected control amount, and then the actuator is fed back so that the rotation speed becomes the target rotation speed. In the idle rotation speed control device to be controlled, the anticipated control is performed based on the basic estimated control amount and a correction control amount determined by the deviation between the rotation speed obtained by the estimated control using a predetermined basic estimated control amount and the target rotation speed. An idle rotation speed control device characterized by comprising an expected control amount determining means for determining the amount.