JPH0833134B2 - Engine speed control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine speed control device, and more particularly to control of an engine speed during idling.

[Conventional technology]

A conventional engine speed control device sets a target speed according to the load of the engine when idling, and installs it in a bypass conduit that bypasses the throttle valve so that the actual engine speed converges to this target speed. Was controlling the air control valve. The control amount includes a basic air amount set according to the load of the engine and a rotation speed feedback correction amount for eliminating the deviation between the target rotation speed and the actual rotation speed. The basic air amount and the target rotation speed are obtained based on the factors that determine the operating state of the engine. Further, the rotation speed feedback correction amount is learned so that the actual rotation speed matches the target rotation speed. When the engine shifts from the idle state to the non-idle state and returns to the idle state again, the rotation speed feedback correction amount learned in the previous idle state is used for the learning in the current idle state.

When the air supply amount to the engine is controlled by controlling the opening of the air control valve as described above, the fuel supply amount to the engine is determined by this air supply amount, and therefore the rotation speed is controlled. I can do things.

[Problems to be Solved by the Invention]

Since the conventional engine rotation speed control device is as described above, in the non-idle state, the detection signal is not taken into the device, and after the electric load that affects the engine load is turned on,
When the engine is returned to the idle state as it is, the rotation speed feedback correction amount learned in the idle state when there is no electric load is used for learning when the idle state is restarted. Therefore, even if the idle state is restarted, the air supply amount corresponding to the electric load is insufficient, and the actual rotation speed temporarily drops below the target rotation speed with the restart of the idle state, or in the worst case, , There was a problem that stalled.

Further, although the decrease in the rotation speed is corrected by learning the rotation speed feedback correction amount, there is a problem that the driving feeling is deteriorated because the response is slow.

The present invention has been made to solve the above problems, and the engine speed when returning to the idle state again by increasing the rotation speed feedback correction amount in response to the shift to the non-idle state. It is an object of the present invention to obtain an engine speed control device capable of preventing an excessive decrease in the engine speed.

[Means for solving the problem]

The engine rotation speed control device of the present invention determines the opening control amount of an air control valve that introduces air into the intake pipe in order to converge the actual rotation speed of the engine to the target rotation speed, the actual rotation speed and the target rotation speed. Of the air control valve is controlled by a correction amount calculation means for calculating a correction amount for correcting the deviation of the air control valve and the opening control amount corrected by the correction amount calculated by the correction amount calculation means. And a control means for controlling the opening of the air control valve by the corrected opening control amount so that the actual rotation speed matches the target rotation speed in an idle state. When the engine shifts from the idle state to the non-idle state, the correction amount calculation means increases and corrects the correction amount, and when the engine shifts to the idle rotation range of the engine, the correction amount calculation means It is obtained so as to calculate a correction amount for correcting the opening control amount of the air control valve.

[Action]

In the engine speed control device according to the present invention, even when the engine load such as the electric load increases in the non-idle state and the state is returned to the idle state as it is, the correction amount calculation means corresponds to the transition to the non-idle state. Since the correction amount is increased and corrected, the increased amount compensates the air supply amount for the increased load, so that the actual rotational speed can be smoothly converged to the target rotational speed.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing an engine speed control device and the like according to an embodiment of the present invention. In the figure, reference numeral 1 denotes an engine mounted on, for example, an automobile, and an air cleaner 2,
Main air is taken in through the intake pipe 3 and the intake branch pipe 4, and fuel is injected and supplied from a single electromagnetic fuel injection valve 5 provided in the intake pipe 3. This fuel amount is determined by a fuel control system (not shown) based on the output signal of the pressure sensor 6 that detects the pressure in the intake pipe 3 as an absolute pressure, for example.

Reference numeral 7 is a throttle valve that adjusts the main intake air amount of the engine 1 by any operation of an accelerator pedal (not shown) by a driver, 8 is a throttle opening sensor that detects the opening of the throttle valve 7, and 9 is a throttle valve. It is an idle switch for detecting the fully closed state of 7.

Reference numeral 10 is a bypass conduit provided so as to bypass the throttle valve 7 on the downstream side of the electromagnetic fuel injection valve 5, and 11 is an air control valve provided between the bypass conduits 10. One end of the bypass conduit 10 is connected to an air inlet provided between the electromagnetic fuel injection valve 5 and the throttle valve 7, and the other end of the bypass conduit 10 is provided downstream of the throttle valve 7. It is connected to the air outlet.

As the air control valve 11, for example, an electromagnetic control valve having an opening degree according to the duty ratio of the applied drive signal is used, and the flow passage cross-sectional area of the bypass conduit 10 is controlled in proportion to the duty ratio.

The ignition device of the engine 1 is connected to an ignition control system (not shown) that forms an ignition signal from the operating state parameter of the engine 1, and the ignition coil 12 is responsive to the ignition signal.
It is composed of an igniter 13 for controlling ON / OFF of the primary current, an ignition coil 12, a distributor (not shown), an ignition plug (not shown) and the like.

Reference numeral 14 is a cooling water temperature sensor that detects, for example, the cooling water temperature representing the temperature of the engine 1, 15 is an electric load switch for turning on a load of auxiliary equipment such as an air conditioner, and 16 is a torque converter signal of an automatic transmission. A signal line 17 is a vehicle speed sensor for detecting a vehicle speed by outputting a pulse signal having a frequency proportional to the rotation speed of the axle. 18 is the exhaust pipe of the engine 1, 19
Is a catalyst, and the air-fuel mixture burned by the engine 1 becomes exhaust gas, which is purified and discharged to the outside.

Reference numeral 20 denotes an electronic air amount control unit which is operated by being supplied with electric power from the battery 21 through the key switch 22, and determines whether or not the idle state is based on the output signals from the idle switch 9 and the vehicle speed sensor 17, and the result of this determination In accordance with the above, the control amount of the air control valve 11 is obtained based on the ignition signal on the primary side of the ignition coil 12, the signal from the cooling water temperature sensor 14, the signal from the electric load switch 15 and the signal line 16, and the air control valve 11 Drive control.

Next, the electronic air amount control unit 20 will be described with reference to FIG. 100 is a microcomputer, which calculates the control amount of idle rotation according to a predetermined program
CPU200, a free-running counter 201 for measuring the rotation cycle of the engine 1, a plurality of timers 202 for measuring the time and duty ratio D every 100 ms, an A / D converter 203 for converting an analog input signal into a digital signal, Consists of an input port 204 for inputting a digital signal as it is, a RAM 205 as a work memory, a ROM 206 for storing the flow of FIG. 3 as a program, an output port 207 for outputting a drive signal, a common bus 208, etc. Has been done. Reference numeral 101 is a first input interface circuit, which waveform-shapes the primary ignition signal of the ignition coil 12 into an interrupt signal and inputs it to the microcomputer 100. When this interrupt signal occurs, C
The PU 200 reads the value of the counter 201, calculates the cycle of the engine speed from the difference from the previous value, and stores it in the RAM 205. Ten
2 is a second input interface circuit, which is a cooling water temperature sensor 14
A / D converter 2 by removing noise from the output signal of
Output to 03. Reference numeral 103 denotes a third interface circuit, which sets the ON signal of the electric load switch 15, the neutral safety signal from the signal line 16 and the pulse of the vehicle speed sensor 17 to a predetermined level and outputs the pulse to the input port 204. An output interface circuit 104 amplifies the drive signal from the output port 207 and outputs the amplified signal to the air control valve 11. A power supply circuit 105 supplies a constant voltage to the battery 21 to the microcomputer 100 when the key switch 22 is turned on.

Next, the operation will be described mainly with reference to FIG. First, in step S1, it is determined whether or not the idle switch 9 is on and the vehicle speed sensor 17 does not generate a pulse, that is, the vehicle is stopped, that is, whether or not the vehicle is in an idle state. If it is in the idle state, the process proceeds to step S2, and the actual rotation speed N _e of the engine 1 is calculated based on the rotation cycle of the engine 1 calculated by an interrupt routine (not shown). In the next step S3, the target rotation speed N _t according to the load of the engine 1 is calculated. For example, depending on whether the cooling water temperature data WT obtained from the cooling water temperature sensor 1, the torque converter signal input from the signal line 16 is the neutral range or the drive range, and the signal from the electric load switch 15 is an ON signal or an OFF signal, Calculate N _t .
Next, in step S4, as in step S3, the basic air amount Q _BASE according to the load is calculated from the cooling water temperature data WT, the torque converter signal, the electric load signal, and the like. In step S5, it is determined whether or not the timing is every fixed time (for example, 100 ms),
If it is not timing, the process proceeds to step S12, and if it is timing, the process proceeds to step S6.

In step S6, the target rotation speed N _t obtained in step S3
And the latest actual rotation speed N _e obtained in step S2
Ask for. In the next step S7, it is determined whether the deviation ΔN is in the dead zone or not, for example, −ΔN ₁ ≦ ΔN ≦ ΔN ₁ . If it is in the dead zone, the actual rotation speed N _e and the target rotation speed N _t substantially match, so in step S8, the N _e ˜N _t match flag is set.
Further, in step S9, the control gain KI is set to 0, and then the process proceeds to step S11. If it is not in the dead zone, N _e and N _t do not substantially coincide with each other, so the routine proceeds to step S10, the control gain KI which is not 0 is calculated using the ΔN map shown in FIG. 4, and the routine proceeds to step S11 after the calculation. In step S11, it updates the Q _NFB current by adding the control gain KI to the actual rotational speed feedback correction amount Q _NFB. In step S12, step S4
The basic air amount Q _BASE obtained in step S11 and the rotation speed feedback correction amount Q _NFB obtained in step S11 or step S17 are added to calculate the idle speed control air amount Q _ISC .

In step S13, the duty ratio D of the drive signal applied to the air control valve 11 is calculated from the Q _ISC map shown in FIG. 5 according to the idle speed control air amount Q _ISC previously obtained. As shown in FIG. 6, when the cycle of the drive signal is T and the ON time in one cycle is T _ON , the duty ratio D is Given in. In step S14, the air control valve 11 is driven with the duty ratio D, and the process returns.

On the other hand, when it is determined in step S1 that the vehicle is not in the idle state (the idle switch 15 is off or the vehicle speed sensor 17 is generating a pulse), the process proceeds to step S15. In step S15, it is determined whether or not the previous non-idle state has occurred in the idle state, that is, whether or not the idle state has transitioned to the non-idle state. This determination is performed by, for example, setting a flag of "1" when the idle state is determined in step S1 and "0" when the idle state is determined.
This is done by setting the flag of and comparing the previous and current flags. When it is determined that the idle state has just transitioned to the non-idle state, the process proceeds to step S16, where N _e ~
It is determined whether the N _t match flag is set.
If it is set, the process proceeds to step S17, where the increased air amount Q _UP (for example, 100 rpm equivalent) is added to the current latest rotational speed feedback correction amount Q _NFB obtained in step S11, and Q is obtained.
Update the _NFB and proceed to step S18. When it is determined in step S15 that the non-idle state continues, or when it is determined in step S16 that the N _{e to} N _t match flag is not set, the process proceeds to step S18.

In step S18, the idle speed control air amount Q _ISC is set to a predetermined air amount Q _OPEN during open control, and the process proceeds to step S19. In step S19, the process proceeds to step S13 after clearing the N _e to N _t match flag, performs the same processing as described above.

After processing in step S14, it returns,
When returning, it returns to step S1 and repeats the above operation.

〔The invention's effect〕

As described above, according to the present invention, when the engine shifts from the idle state to the non-idle state, the correction amount calculating means increases and corrects the correction amount, and then increases when the engine shifts to the idle rotation range. By calculating the correction amount for correcting the opening control amount of the air control valve based on the corrected correction amount, it is possible to prevent an unnecessary increase in the actual rotation speed when returning to the idle rotation range from the non-idle state. In addition, the actual rotation speed can be smoothly converged to the target rotation speed with good responsiveness, the driving feeling is good, and the vehicle does not suddenly start.

According to the second aspect of the invention, the correction amount is increased and corrected when shifting from the idle state where the actual rotation speed and the target rotation speed almost coincide with each other to the non-idle state. Therefore, when the cycle of the idle state and the non-idle state is repeated in a short time, the increment of the correction amount is prevented from being repeatedly added, and the feedback addition is performed when shifting from the non-idle state to the idle state by this repeated addition. There is an effect that it is possible to prevent the convergence of the rotation speed from being deteriorated too much.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an engine speed control device and the like according to an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of an electronic air amount control unit and the like in FIG. 1, FIG. 3 is a flow chart showing the operation of one embodiment of the present invention, and FIG.
FIG. 5 is a diagram showing the N map, FIG. 5 is a diagram showing the relationship between the idle speed control air amount and the duty ratio, and FIG. 6 is an explanatory diagram for explaining the duty ratio. In the figure, 1 ... engine, 3 ... intake pipe, 7 ... throttle valve, 9 ... idle switch, 10 ... bypass conduit,
11 ... Air control valve, 12 ... Ignition coil, 13 ... Igniter, 17 ... Vehicle speed sensor, 20 ... Electronic air volume control unit, 21 ... Battery. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (2)

[Claims] 1. An opening control amount of an air control valve for introducing air into an intake pipe in order to converge an actual engine speed to a target engine speed in a direction in which a deviation between the actual engine speed and a target engine speed is eliminated. A correction amount calculation means for calculating a correction amount to be corrected; and a control means for controlling the opening of the air control valve with the opening control amount corrected by the correction amount calculated by the correction amount calculation means, In an engine speed control device for controlling the opening of the air control valve by the corrected opening control amount so that the actual speed matches the target speed in an idle state, the engine is in an idle state. The correction amount calculation means increases and corrects the correction amount in the case of shifting from the non-idle state to the non-idle state. Controlled variable Speed control apparatus for an engine is characterized in that so as to calculate a correction amount for correcting. 2. The correction amount calculation means increases and corrects the correction amount when the actual rotation speed substantially coincides with the target rotation speed, and when the idle rotation state shifts to the non-idle rotation state. The engine speed control device described.