JPH033945A - Engine control device - Google Patents

Abstract

PURPOSE:To invariably detect the engine rotating speed precisely by controlling the timing of the ignition and fuel injection based on the reference signal extracted in the preset mask period. CONSTITUTION:When the rotation of a rotor 1 synchronous with a crank shaft is detected by a pick-up coil 2 and the crank rotation signal S0 is generated, it is converted into the reference pulse S1 by the wave-form shaping circuit 3 of a control unit 12. A microcomputer 5 calculates using the pulse S1 as a reference, and an I/OLSI 4 generates the ignition signal S2 and the fuel injec tion signal S3 to control ignition and fuel injection. The mask period preventing the chattering noise of the reference pulse S1 is set by counting the time from the previous interruption by the detection of the reference pulse S1 waveform- shaped and extracted with the crank rotation signal So to the current interrup tion. The rotating speed is precisely detected, and the control with good respon siveness is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an engine control device, and in particular to an engine control device having an engine rotation speed detection device suitable for ignition timing control equipment and fuel injection control devices for automobile gasoline engines. Regarding equipment.

[Conventional technology]

The conventional engine control device is disclosed in Japanese Patent Application Laid-Open No. 63-188770.
As described in the publication, as an engine rotation speed detection device,
The period of the negative signal voltage waveform on the primary side of the ignition coil was measured, a mask period was set to eliminate the effects of chattering, and this was done using software.

In addition, a crankshaft rotation signal is used as the engine rotation speed detection device, and the rotation angle position of the crankshaft is detected by distinguishing three pulse signals per cylinder of one rotation signal, and the above pulse signal is detected. Regarding the device that controls the engine's ignition timing and injection timing based on the reference elapsed time, no software measures were taken to eliminate the effects of chattering.

[Problem to be solved by the invention]

In the above conventional technology, when a crankshaft rotation signal is adopted, the crankshaft rotation signal waveform has a large waveform disturbance including chattering noise depending on the operating condition, so this waveform is shaped as it is and used as a reference pulse. This will result in incorrect period measurement, and depending on the type and size of the noise, it may not be possible to process it with the hardware.
When the operating state of the engine is taken into account, there is a problem in that it is difficult to always maintain high accuracy in detecting the engine rotation speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine control device that sufficiently suppresses the influence of chattering that occurs on a crankshaft rotation signal and is equipped with means that can always accurately detect engine rotation speed despite changes in engine operating conditions. It is in.

[Means to solve the problem]

In order to achieve the above object, an engine control device according to the present invention uses software masking processing to remove the influence of chattering that cannot be processed by hardware on a reference pulse signal detected from a crankshaft rotation signal. .

[Effect]

The above engine control device takes in the reference pulse signal by setting multiple mask periods to deal with chattering noise in the crankshaft rotation signal caused by engine operating conditions. However, it is possible to sufficiently eliminate the influence of chattering. In addition, since the mask period is selectable from the software processing, there is no logic complexity and there is no response delay.Furthermore, the software miking process has unique characteristics other than the pre-estimated signal input timing. If a signal is input,
It ignores this and operates so as not to consider it as an input, so it does not measure signals with unusual timing, so there is no possibility of malfunction. As a result, even when three signals for each cylinder are input into the rotation angle signal of the crankshaft rotation signal, it is possible to measure the engine rotation speed with high accuracy by eliminating the effects of chattering, and also to The timing of fuel injection can be appropriately controlled.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 2 is a block diagram showing an embodiment of the engine control device according to the present invention. In FIG. 2, 1 is a rotor for detecting a crankshaft rotation signal that rotates in synchronization with the crankshaft, 2 is a pickup coil located in the rotating part, 3 is a waveform shaping circuit including an input circuit for a crankshaft rotation signal, and 4 is T10 LSI for pulse input, 5 is microcomputer (CPU)
, 6 is an ignition coil drive circuit, 7 is an ignition coil, 8
9 is a distributor, 9 is an injector drive circuit, 1o is a spark plug, 11 is an injector, and 12 is a control unit.

9 on the outer periphery of the rotor 1 for detecting the crankshaft rotation signal mentioned above.
Three protrusions are provided for each 0', and when each protrusion passes directly under the pick-up coil 2, the magnetic flux passing through the pink-up coil 2 changes and three signals of the crankshaft rotation signal So are generated. . These three signals generate signals with the same shape for each cylinder of the engine as crankshaft rotation angle position signals, the first signal is made to match the ignition timing at engine startup, and the second signal is used to match the ignition timing at engine startup. The third signal is outputted between the second signal of each cylinder and the first signal of the cylinder that travels one stroke in time from the cylinder, so as to coincide with the start time of energization to the ignition coil 7 at the time of starting. , the time between each signal is measured, and each signal is identified based on the length of the time. In addition, the microcomputer (CPU) 5 has a built-in backup CPU in case of engine control abnormality, and when an abnormality occurs, the CPU
switches to backup mode and performs backup ignition (injection) control in synchronization with the first signal.

The above-mentioned rotor 1 and pink-up coil 2 for detecting the crankshaft rotation signal are built into the ignition power distribution distributor 8, and the rotor is attached to the distributor shaft to synchronize the rotation angle position signal of the crankshaft with the camshaft rotation. It can also be generated.

With the above configuration, the rotor 1 rotates in synchronization with the crankshaft.
The crankshaft rotation signal So is detected by the pink-up coil 2 located at the rotating part. This rotation signal So is converted into a reference pulse signal S1 by a waveform shaping circuit 3 including an input circuit of the control unit 12. The pulse input/output I10 LSI 4 and the microcomputer 5 use the pulse signal S1 as a reference time signal to determine the ignition timing, energization time, and fuel injection amount in conjunction with other input conditions.
It outputs an ignition signal S2 and a fuel injection signal S3.

This ignition signal S2 controls the current flowing from the 12V power supply to the ignition coil 7 through the ignition coil drive circuit 6, and the high voltage signal generated in the ignition coil 7 is passed through the distributor 8 to the ignition plugs (spark plugs) of each cylinder (4 cylinders). ) divided into 10. Also, fuel injection signal S3
The fuel injection time of the engine injector 11 is controlled through the injector driver circuit 7. The engine rotational speed necessary for determining the fuel injection amount is detected by taking in the reference pulse signal S1 and performing arithmetic processing on the microcomputer 5.

At this time, it is necessary to provide a mask period in order to prevent chattering noise in the reference pulse signal SL.

Next, a method of setting the mask period and an engine control operation will be explained.

FIG. 1 is a flowchart of mask setting of the crankshaft reference pulse signal S1 and engine control operation shown in FIG. In FIG. 1, this process is executed by an interrupt caused by the detection of a reference pulse signal S1 obtained by waveform-shaping the crankshaft rotation signal So. First, in step a, when an interrupt of the pulse signal Sl occurs, in step b, from the previous pulse signal S1 interrupt to the current pulse signal S! A timer counts the time until the interrupt occurs to measure the interrupt period.Next, in step C, it is determined whether or not the engine is being started based on the engine operating state, which is a constant engine rotational speed in this example. If the result of this determination is that the engine is starting, it is determined in step d whether the count data Ix has reached a predetermined mask setting value of 1 or more, and if the engine is not starting, it is determined in step e that the count data Ix has reached the predetermined mask setting value. It is determined whether the value is 2 or more. However, if the count data Ix is equal to the engine rotation speed (setting value 1)> (setting value 2), and if the count data Ix is greater than or equal to the mask setting value 1 or 2, then in step f, a false interrupt is counted due to chattering noise. Since the data TNors+: is zero, it is held as I x+ TNOISE→interrupt cycle data, and TNOISE is cleared in step g. After that, in step j, fuel injection control and ignition timing control are performed. If the count data 1x is equal to or less than the mask setting value 1 or 2 as a result of the judgment, there is count data Tvo+sE of an erroneous interrupt caused by chattering noise in step h, so processing is completed as I x+ Tworsε→TNorsε, and the next interrupt occurs. wait.

FIG. 3 is a time chart of the signal waveform in which the chattering noise of FIG. 2 occurs. In FIG. 3, the interrupt pulse signal Sl detected by the crankshaft rotation signal So is not only detected by the three signals of the crankshaft rotation signal So, but also interrupt pulses generated by chattering noise. Steps d and e in Figure 1 are executed, and if Ix≧set value 1, 2, IX+ is determined in step h.
TNOISE: A mask is activated by a mask signal S1 with a pulse width of mask setting values 1 and 2 corresponding to the interrupt cycle data T as TsorsE, and this distinguishes between a valid interrupt signal and an erroneous interrupt signal. It is masked and erroneous measurement of engine speed is eliminated.

FIG. 4 is a time chart of signal waveforms during engine starting in FIG. 2. FIG. 5 is a time chart of signal waveforms in the engine high speed range shown in FIG. 2.

If the mask setting value 1 in steps d and a in FIG. 1 is the value in the low engine speed range during engine startup, and the mask setting value 2 is the value in the high engine speed range,
The relationship between chattering noise and mask setting values 1 and 2 is as shown in FIGS. 4 and 5, respectively. In the low rotation range during engine startup as shown in Fig. 4, the period of the effective interrupt pulse signal S1 by the crankshaft rotation signal So becomes longer, so the mask period of the mask signal S1 with mask setting value 1 also becomes longer to mask chattering noise. do. In the high engine speed range shown in FIG. 5, the period of the effective interrupt pulse signal Sl becomes short, so the mask period of the mask signal S' with the mask setting value 2 also becomes short, thereby masking chattering noise.

FIG. 6 is a time chart of the rotation period and interrupt period of the signal waveform shown in FIG. In FIG. 6, assuming that the rotation period of the crankshaft rotation signal So in a noise-free state for each cylinder is To, three effective signals generated by the three signals of the crankshaft rotation signal So are The interrupt cycle data of the interrupt pulse signal Sl is Ti r T
When z + Ts, timer setting values 1 and 2 are adjusted to the transient operating state of the engine so that they are smaller than the shortest interrupt cycle data T2 among the interrupt cycle data corresponding to the rotation cycle To of a constant engine rotation speed. Decide by taking into account. Furthermore, the masking for chattering noise in the crankshaft rotation signal So is actually effective when the output of the crankshaft rotation signal So is small when the engine rotation speed is low during starting as shown in FIG. , at this time, the period during which chattering appears in the detection pulse signal S1 of the crankshaft rotation signal So is also long, so the mask setting value 1 at this time is set to a sufficiently long value under the condition that it is smaller than the above-mentioned interrupt cycle data T2. In the high speed range of the engine shown in the figure, the output of the crankshaft rotation signal So becomes large, so there are few problems, and at this time, the period during which chattering noise appears in the detection pulse signal S1 is relatively short, so the mask setting value at this time is 2 can be set to a sufficiently short value under the condition that it is smaller than the above-mentioned interrupt cycle data T2 so that the engine rotation speed can be used up to a sufficiently high engine speed.

In the above embodiment, the mask period of the reference pulse signal S1 of the crankshaft rotation signal So is set to the setting value 1 at low rotation (starting) and the setting value 2 at high rotation to the highest among the three signals of the crankshaft rotation signal So. Two mask settings can be achieved by setting an appropriate value in consideration of the engine operating state and corresponding to the chattering noise generation state under conditions smaller than the interrupt cycle data T2 between the short 2nd and 3rd signals. By switching between values 1 and 2, it is possible to provide an effective mask in the low rotational speed range when starting the engine, which is particularly important. The present invention is not limited to the method of dividing the mask setting value into two types based on the determination result of whether or not the engine is being started at a constant engine speed as in the above embodiment, but the present invention is also applicable to the occurrence of chattering and the engine operating state based on other conditions. By determining the relationship of It is possible to perform fuel injection control and ignition timing control.

〔Effect of the invention〕

According to the present invention, the setting value of the masking period for the chattering noise of the crankshaft reference pulse signal can be automatically selected and performed based on the determination of the operating state of the engine, such as whether or not the engine is being started. So,
This has the effect of increasing the reliability of the engine control device by detecting the engine rotational speed more accurately, improving responsiveness to engine operating conditions, and preventing malfunctions caused by various noises.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a crankshaft pulse signal mask setting operation showing an embodiment of the engine control device according to the present invention, and FIG. 2 is a block diagram of the same engine control device.
Figure 3 is a time chart of the chattering noise generation signal waveform, Figure 4 is a time chart of the engine start raw signal waveform, Figure 5 is a time chart of the engine high speed range signal waveform, and Figure 6 is the same signal waveform. 2 is a time chart of the rotation period and interrupt period. 1... Rotation signal detection rotor, 2... Pick-up coil, 3... Waveform shaping circuit, 4... Pulse input equipment/○LSI, 5... Microcomputer (CPU), 6... Ignition coil Drive circuit, 7... Ignition coil, 8...
Distributor, 9... Injector driver circuit. 10...Spark plug, 11...Injector. 12...Control unit, a=k...Processing El step. Katsuma Ogawa (

Claims (1)

[Scope of Claims] 1. An engine control device having a waveform shaping circuit that inputs a crankshaft rotation signal and outputs a reference pulse signal, and means for calculating an engine rotation speed from a measurement period of the reference pulse signal. 1. An engine control device comprising means for controlling ignition and fuel injection timing based on a reference pulse signal captured by setting a mask period. 2. The engine control device according to claim 1, wherein the mask period is switched depending on the operating state of the engine. 3. The engine control device according to claim 1, wherein three signals are inputted for each cylinder of the engine as rotation angle signals of the crankshaft rotation signal. 4. The engine control device according to claim 3, wherein the rotation angle signal of the crankshaft rotation signal is generated in synchronization with the camshaft rotation. 5. The engine control device according to claim 4, wherein a sensor for detecting the rotation angle signal of the crankshaft rotation signal is built into the ignition power distribution distributor. 6. Match the reference pulse signal of the first signal of the three signals input for each cylinder with the ignition timing at engine startup, and perform backup ignition control in case of engine control abnormality in synchronization with the reference pulse signal. 4. The engine control device according to claim 3, wherein the engine control device performs the following steps. 7. Measure the time differences between the three signals input for each cylinder, compare at least two of each time difference,
4. The engine control device according to claim 3, wherein three signals for each cylinder are identified from the ratio.