JPH02233875A - Knocking controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce a burden on a hardware part by installing four means for securing a peak value signal from detector output, securing a leveling signal, making out a threshold from this leveling signal and comparing the peak valve signal with the threshold, respectively. CONSTITUTION:An output signal of a knock sensor 1 is filtered of its band wave by a band pass filter 2, and a peak value and a mean value are secured at each cylinder by a peak hold circuit 11 and a leveling circuit 12. First, a peak hold signal is converted into analog-to-digital, securing a signal Vp, then a reset signal is fed to the circuit 11 from a microcomputer 9A, successively a leveling signal is converted into analog-to-digital likewise, securing a signal VA. Next, this signal VA is amplified into offset addition and thereby a knock discriminating threshold value VTH is operated. Then, a comparison between Vp and VTH takes place, and when a difference Vk between both of them is positive, it is so judged that there is knocking, and timing delay compensation processing is carried out, thereby finding knock timing delay control thetaR=VkXL (L is compensating rate), and knock compensation timing delay value thetaR=thetaR+ thetaR is operated.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention... This invention relates to an internal combustion engine knock control device for controlling knocking in an internal combustion engine. [Prior Art] FIG. 4 is a block configuration diagram showing the configuration of a conventional knock control device for an internal combustion engine. In the figure, (1) is a knock sensor that is attached to the engine and detects engine knocking, (2) is a bandpass filter that filters the band of the output signal from knock sensor (1), and (3) is a gate circuit. ．．
The output signal from the bandpass filter (2) is gated by a mask signal from the microcomputer (9). (4) is a BGL circuit. Based on the output signal from the gate circuit (3), the background level (BGL
). (5) is a comparator. Compare the output signal from the gate circuit (3) and the output signal from the BGL circuit (4). (6) is an integrator that integrates the output signal from the comparator (5) and is reset by a reset signal from the microcomputer (9), which will be described later. The knock detection circuit (7) is composed of the above means except the knock sensor (1), and (8) is an A/D converter. The analog signal from the calculator (6) is sent to the microcomputer (
9) Convert it to a digital signal for import into the computer. The microcomputer (9) includes a retard correction processing means (10) that performs retard correction processing based on the output signal from the A/D converter (8). The conventional knock control device for an internal combustion engine is configured as described above.The detection signal from the knock sensor (1) (Fig. 5(a)) is a diagram showing operating waveforms.
) is input to a bandpass filter (2), where a predetermined band is filtered and supplied to a gate circuit (3). Since a mask signal (see Fig. 5(b)) is applied from the microcomputer (9) to the gate circuit (3), the output signal of the bandpass filter (2) is masked at a predetermined period, and the gate circuit (3) is masked. The output signal of circuit (3) is as shown in Figure 5(c). The output signal of this gate circuit (3) is applied to one input of the comparator (5). Further, the output signal of the gate circuit (3) is applied to the BGL circuit (4) to form a predetermined background level as shown in FIG. 5(d). This background level is applied to the other input of the comparator (5). It is compared with the output signal of the gate circuit (3) mentioned above. The signal obtained from the comparator (6) is calculated by the integrator (6), and an integral value as shown in FIG. 5(e) is obtained. In order to obtain this integral value for each cylinder, a reset signal is supplied to the integrator (6) from the microcomputer (9) for each cylinder. The integrated value voltage obtained by the integrator (6) is converted to an A/D converter (8 converter).
Load the unconverted digital signal (V.) into the microcomputer (9). The retard angle correction processing means (10) calculates and controls the knock correction retard angle control angle (80,) from the following formula.

ΔθR = V * X N N: Correction factor [
Problems to be Solved by the Invention] In the conventional knock control device for an internal combustion engine as described above. Since the signal processing up to knock detection is performed in hardware, the circuitry is complex and the burden on the hardware for control is large.
The problem was that it was expensive. This invention... The purpose of this invention is to provide a knock control device for an internal combustion engine in which the burden on one hardware part is small, the circuit is simple, and the knock discrimination processing is performed by a microcomputer. [Means for Solving the Problems 1] A knock control device for an internal combustion engine according to the present invention includes: a detector for detecting a knocking state of the engine; a knock detection means for determining knocking from a signal of the detector; An internal combustion engine comprising: a control amount calculating means for calculating the knocking control amount based on the output of the means; and a retardation correction processing means for retarding the ignition timing in a direction to suppress knocking based on the control amount. The knock control device includes a peak hold means for obtaining a peak value signal from the detector output, an averaging means for obtaining an averaged signal from the detector output, and a threshold for creating a threshold from the averaged signal of the averaging means. The apparatus includes a generating means and a comparing means for comparing the peak value signal and the threshold. [Operation] In this invention. Knocking is determined based on the output of the comparing means, and in the case of knocking, the ignition timing is controlled by the retardation correction processing means so as to suppress the knocking of the engine.

[Embodiment] FIG. 1 is a block diagram showing a knock control device for an internal combustion engine according to an embodiment of the present invention.
(2), (8), and (10) are the same as the conventional ones. (11) is a peak hold circuit which peak holds the output signal from the band pass filter (2) to obtain a peak value signal. Also. A reset signal is applied to the peak hold circuit (11) from a microcomputer (9A), which will be described later, only during a period when no knock occurs. (12) is an averaging circuit. Average the output signals from the bandpass filter (2) to obtain an average value signal. Bandpass filter (
2), peak hold circuit (11), and averaging circuit (
12) and a knock interface circuit (13) is formed. (14) is the amplification/offset addition means,
The average value from the averaging circuit (12) is sent to the A/D converter (8).
The signal (■6) obtained by conversion is amplified and offset is added to set the knock discrimination threshold (■, l.l). (15) is a comparison means, and the peak hold circuit (11) The signal (■P) obtained by converting the peak value from the A/D converter (8) is compared with the above-mentioned knock discrimination threshold (V, .), and a knock discrimination process is performed. The microcomputer (9A) includes an amplification/offset addition means (14), a comparison means (15), and a retard angle correction processing means (10).

FIG. 2 is a diagram showing operating waveforms of each part in FIG. 1.

Figure 3 is a diagram showing the operation flowchart of the microcomputer. In the knock control device for an internal combustion engine configured as described above, the output signal of the knock sensor (1) shown in FIG. 2(b) is bandpass filtered by the bandpass filter (2). Peak hold circuit (11) and averaging circuit (1
2), a peak value as shown in FIG. 2(c) and an average value as shown in FIG. 2(d) are obtained for each cylinder. The peak hold reset signal as shown in FIG. 2(a) is supplied from the microcomputer (9A) only during the period when no knock occurs. This peak value is obtained only during the knock occurrence period. In response to this peak value and the average value, the microcomputer (9A) performs knock discrimination using the processing steps shown in FIG. Performs retardation correction processing. first. In step S1 of FIG. 3, the aforementioned peak hold signal is converted by the A/D converter (8) to obtain a signal (Vp). next. In step S2, the microcomputer (9A
) supplies a heliset signal to the peak hold circuit (11). Next, the process proceeds to step S3, where the averaged signal described above is converted by the A/D converter (8) to obtain a signal (VA). This converted signal (VA) is amplified, offset 1, and added by means (14). Amplify by a factor of I and add V Q l t offset to set the knock detection threshold (V,.=VAXK
+V. , t). Step S5
Knock determination processing is performed by comparing the Vp obtained in step 1 with the threshold V yll obtained in step S4. When this comparison (V.=Vp vTM) is positive in step S6, it is determined that there is a knock, and the process proceeds to step S8, where retardation correction processing is performed and the knock retardation control angle (retardation amount) Δθ*=VKX
L = (Vp - Vtl.I) x L (.:
In this case, L is a correction skewer. ). If the above comparison is not positive in step S6, it is determined that there is no knock. Proceeding to step S7, the above retarded view ΔθP-0 is calculated. Next, the process proceeds to step S9, where the knock correction retard amount θ is determined based on the retard amount obtained in the above step. = θ+Δθ is calculated.

[Effects of the Invention] As explained above, the present invention includes a detector for detecting a 7 knocking state between 1 and 1, a knock detection means for determining knocking from the signal of this detector, and an output of this knock detection means. a knock control device for an internal combustion engine, comprising: a control amount calculating means for calculating the knocking control amount based on the control amount; and a retard correction processing means for retarding the ignition timing in a direction to suppress knocking based on the control amount. , peak hold means for obtaining a peak value signal from the detector output; and averaging means for obtaining an averaged signal from the detector output;
comprising a threshold creating means for creating a threshold from the averaged signal from the averaging means, and a comparing means for comparing the peak value signal and the threshold,
Comparison means 1 Threshold creation means. The retardation correction means, etc. were created using a microcomputer. The burden on the hardware is small, the circuit is simple, and since the knock discrimination processing is performed by a microcomputer, it is possible to perform knock discrimination control on an individual basis, making it possible to perform inexpensive and fine-grained retardation correction. This has the effect of making it possible to obtain a device with high controllability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a knock control device for an internal combustion engine according to an embodiment of the present invention. Figure 2 is an operation waveform diagram of each part in Figure 1, and Figure 3 is an operation flowchart of the microcomputer. Fig. 4 is a block diagram of a conventional knock control device for an internal combustion engine, and Fig. 5 is an operational waveform diagram of each part in Fig. 4. In the figure, (1)...knock sensor. (2
)... Bandpass filter. (9A>...Microcomputer, (8)...A/D converter, (10)...
...Retard angle correction processing means, (11)...Peak hold circuit, (12)...Averaging circuit, (13)...Knock interface, (14)...Amplification/offset/
Addition means, (15)... Comparison means. In addition. The same symbols in each figure indicate the same or equivalent parts. Agent So Gado Teruaki 3 Heisei

Claims (1)

[Claims] a detector for detecting a knocking state of the engine; a knock detection means for determining knocking from a signal of the detector; a control amount calculation means for calculating a control amount of the knocking based on the output of the knock detection means; A knock control device for an internal combustion engine, comprising: a retard correction processing means for retarding the ignition timing in a direction to suppress knocking based on a control amount; a peak hold means for obtaining a peak value signal from the output of the detector; averaging means for obtaining an averaged signal from the detector output; threshold setting means for setting a threshold from the averaged signal from the averaging means;
Comparing means for comparing the peak value signal and the threshold, the knocking is determined based on the output of the comparing means, and in the case of knocking, the ignition timing is controlled by the retardation correction processing means to suppress knocking of the engine. A knock control device for an internal combustion engine, characterized in that: