JPS6336416B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for an internal combustion engine using a digital computer, and particularly to input processing means for various detection switch signals.

[Prior Art] Recently, a device has been developed that uses a digital microcomputer to control the fuel supply amount, ignition timing, exhaust gas recirculation amount, etc. of an internal combustion engine.

In the above control device, in addition to analog variables such as the engine speed, intake air amount, and engine temperature, the signals indicating the operating status of the internal combustion engine include the throttle fully closed switch, the neutral switch of the transmission, and the air conditioner switch. It inputs signals from various switches, such as a switch that indicates the operating status of the Yona, and a starter switch that indicates that cranking is in progress.

In conventional control devices, the above analog quantities undergo analog-to-digital (AD) conversion,
Since the signals of the various switches mentioned above are binary signals of on and off, they are inputted as interrupt request signals to the microcomputer as digital signals.

For example, if the signal of the throttle fully closed switch, which is turned on when the throttle valve is fully closed and turned off in other cases, changes from on to off, it indicates that the throttle is in an accelerating state, so the above signal changes from on to off. Interrupts when In other words, the computer temporarily stops the program being calculated, performs the calculation of the acceleration correction program, and after completing the calculation, returns to the calculation of the previous program.

When the switch signal is used as the computer's interrupt request signal as described above, the input circuit is simplified, and since calculations using the switch signal can be performed preferentially, there is an advantage of good responsiveness.

[Problem to be solved by the invention]

However, when the number of switches increases, a problem arises in that a large number of interrupt requests intersect, and the mechanism becomes complex both in terms of hardware and software in order to set priorities among them.

In particular, in the case of a switch, since there are only two values, on and off, an interrupt request is made even if it turns on or off momentarily when it is not originally necessary, so an increasingly large number of interrupt requests become complicated. However, there is also the possibility that other calculations can be made. For example, in the case of the fully closed throttle switch mentioned above, when the vehicle's transmission is operated, the fully closed throttle switch is turned on for a short period of time and then turned back off, so an interrupt request is made every time the switch is operated in response to the acceleration state. Arithmetic processing is performed and the amount of fuel supplied increases. However, when operating the transmission as described above, there is no need to increase the amount of fuel supplied, and there is a risk that this may have an unfavorable effect on exhaust purification measures. In addition, correction calculations (cold start correction, etc.) may also be performed when the starter switch is turned off after being turned on, but in this case, the starter switch may repeatedly turn on and off in a very short period of time. In some cases (in the case of a startup failure or in the case of a hot restart and no correction is required), the correction calculation may not be necessary. If an interrupt is issued immediately when the state of the switch is simply reversed, an interrupt will occur even when an interrupt is unnecessary, as described above, resulting in a large number of interrelated interrupts, which will cause other necessary operations to be performed as described above. Problems arise, such as interfering with

SUMMARY OF THE INVENTION An object of the present invention is to provide a control device for an internal combustion engine that eliminates the inconvenience caused when a switch signal is directly used as an interrupt request signal as described above.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a first means for outputting a signal corresponding to the on/off state of one or more switches for detecting the operating state of the internal combustion engine, and a first means for outputting a signal corresponding to the on/off state of one or more switches for detecting the operating state of the internal combustion engine; Determine whether the switch is on or off by sampling at intervals, and when the state of the switch changes after the on or off state continues for a predetermined number of sampling times, register the calculation execution corresponding to the switch. and a third means for performing a predetermined operation in response to a change in the state of the switch based on the registration.

That is, in the present invention, rather than using the signals of various switches as interrupt request signals to perform corresponding calculations, the signals of various switches are sampled at a predetermined period to determine whether the switch is on or off. registration of calculation execution corresponding to the switch (registering the execution of the calculation) only when the state of the switch changes after the on or off state continues for a predetermined number of sampling times or more. Specifically, by setting an acceleration flag to 1 (for example, as shown in FIG. 2, which will be described later), calculations corresponding to changes in the state of the switch are performed.

The present invention will be explained in detail below based on the drawings.

FIG. 3 is a block diagram showing the functionality of the present invention.

In FIG. 3, a first means 10 outputs a signal corresponding to the on/off state of one or more switches (for example, SW ₁ in FIG. 1 described later) for detecting the operating state of an internal combustion engine (not shown). This is, for example, a circuit consisting of a power supply Vcc and resistors R ₁ , R ₂ , and R ₃ shown in FIG. 1 described later.

Next, the second means 20 determines whether the switch is on or off by sampling the above signal at a predetermined period, and after the on or off state continues for a predetermined sampling number or more, the switch is turned off. When the state of the switch changes, the execution of the operation corresponding to the switch is registered.

Further, the third means 30 performs a predetermined operation according to the change in the state of the switch according to the above registration, that is, performs an originally planned change in the state of the switch as defined by the number of sampling times. It performs the calculations determined accordingly. Then, an internal combustion engine (not shown) is controlled according to the calculation result of the third means 30.

The above second means 20 and third means 30 are:
It is composed of the internal functions of a digital computer, and corresponds to, for example, the microcomputer _M1 shown in FIG. 1 described later. 20 corresponds to blocks _P1 to _P10 , and third means 30 corresponds to (other routines).

[Embodiments of the invention]

FIG. 1 is a diagram showing an embodiment of the present invention.

In Figure 1, SW ₁ is a throttle fully closed switch that is turned on when the throttle valve is fully closed and turned off at other times, M ₁ is a microcomputer, DP ₁ is a digital input port of microcomputer M ₁ , and P ₁ to P ₃ is resistance.

In the circuit shown in FIG. 1, a constant voltage _V1 is applied to the digital input port _DP1 while the throttle fully closed switch _SW1 is on.

Next, FIG. 2 is an embodiment of a flowchart showing the operation of the present invention.

FIG. 2 shows a routine that is processed every 10 msec. First, in block _P1 , the signal of the throttle fully closed switch _SW1 is sampled.

Next, in block _P2 , it is determined whether the throttle fully closed switch _SW1 is on or off (if it is on, the sampling value is _V1 ; if it is off, it is 0), and if it is on (throttle valve fully closed), the idle flag is set to 1. (Set) to clear the ACC counter, and thereafter, as long as the on state continues, the ACC counter is incremented by 1 each time the routine is repeated every 10 msec. When the value of the ACC counter exceeds the predetermined value TD, the ACC counter does not increase any further and becomes a constant value (blocks P ₃ to _{P 6} ).

On the other hand, if the throttle fully closed switch SW ₁ is off (throttle valve open), the value of the ACC counter is compared with the predetermined value TD, and if ACC > TD, the acceleration flag is set to 1 (set), and the Set the flag to 0. If ACC≦TD, the idle flag is directly set to 0 (not set) (blocks P ₇ to _{P 10} ).

That is, the acceleration flag is set when the throttle fully closed switch _SW1 remains on for a predetermined number of sampling times or more (at this time, ACC>TD) and then turns off.

Once the acceleration flag is set, the subsequent routine (indicated as "Other Routines" in Figure 2) performs correction calculations corresponding to acceleration (calculations such as advancing the timing of fuel injection or advancing the ignition timing). It can be done. That is, by setting the above-mentioned acceleration flag, execution of the above-mentioned correction calculation is registered, and the corresponding calculation is thereby started.

In the above example, when the switch is turned off after being in the on state for a predetermined number of sampling times or more, the configuration is such that calculation execution is registered and the calculation corresponding to the change in the state of the switch is performed. However, it may be configured such that when the off state is continued for a predetermined number of sampling times or more and the off state is turned on, the calculation execution is registered and the calculation is performed.

In addition, as a switch, for example, neutral
There are switches, starter switches, air conditioner switches, etc.

Note that when a plurality of switches are combined and the combination of on/off states of the switches changes after continuing for a predetermined number of sampling times or more, the calculation execution is registered and the calculation corresponding to the change in the state of the switches is performed. It may be configured as follows.

〔Effect of the invention〕

As explained above, in the present invention, signals from various switches are applied to the digital input port, and by sampling at a predetermined period, it is determined whether the switch is on or off, and the on or off state is determined by the predetermined sampling. When the state of the switch changes after the switch continues for a number of times, execution of the calculation is registered for the first time, and the calculation corresponding to the change in the state of the switch is performed.

Therefore, since the signals of various switches are not used as they are as interrupt request signals, the number of interrupt elements can be greatly reduced, the software that determines the priority of interrupt requests is simplified, and the hardware is also simplified. The number of interrupt input ports can be reduced.

Furthermore, when the state of the switch changes after the switch has been on or off for a predetermined number of sampling times, the calculation execution is registered and the calculation corresponding to the change in the switch state is performed. There is no possibility that drivability etc. will be impaired due to necessary calculations. Furthermore, in the present invention, the registration of calculation execution occurs only in the originally required state, that is, when the state of the switch originally planned as specified by the number of samplings occurs, and in response to the change in the state of the switch. Since the predetermined calculations are performed using the predetermined calculations, it is possible to eliminate unnecessary calculations. Furthermore, in the present invention, it is determined by sampling whether a switch that detects a predetermined operating state continues to be on or off, and the state is constantly monitored while the switch is on or off. I'm monitoring it. Therefore, if the switch is repeatedly turned on and off during the above sampling, sampling will be performed again from the time when the state is reversed, so it is possible to always accurately determine whether the switch's state continues, and the execution of unnecessary calculations will not start. In addition, when it is originally necessary, the execution of an operation can be reliably registered and the corresponding operation can be executed.

[Brief explanation of the drawing]

Fig. 1 is an embodiment of the present invention, Fig. 2 is a flowchart showing the operation of the invention, and Fig. 3 is an embodiment of the present invention.
The figure is a functional block diagram of the present invention. <Explanation of symbols> SW ₁ ... Throttle fully closed switch, M ₁ ... Microcomputer, DP ₁ ...
…Digital input port, _R1 to _R3 …Resistor.

Claims (1)

[Scope of Claims] 1. In an internal combustion engine control device using a digital computer, a first means for outputting a signal corresponding to the on/off state of one or more switches for detecting the operating state of the internal combustion engine; By sampling the above signal at a predetermined period, it is determined whether the switch is on or off, and when the state of the switch changes after the on or off state continues for a predetermined sampling number or more, the switch is activated. A control device for an internal combustion engine, comprising: second means for registering execution of a corresponding calculation; and third means for performing a predetermined calculation in response to a change in the state of the switch based on the registration. . 2 As the above switch, use a throttle fully closed switch that is turned on when the throttle valve is fully closed, and when the throttle fully closed switch is turned off after being on for more than a predetermined number of sampling times, register the calculation execution. The control device for an internal combustion engine according to claim 1, wherein the control device for an internal combustion engine is configured to perform calculations corresponding to an acceleration state.