JP2000130247A - Engine knocking determination device, determination method, and ignition timing control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably set a knock judging region, and correctly judge knock by finding out a lower limit value by treating the lower limit value about a knock signal, multiplying a prescribed correcting coefficient by the lower limit value, and calculating a knock judging slice level reflecting an obtained value. SOLUTION: During operation of an engine, in an ECU 10, a knock signal 190 inputted to an input circuit 191 is inputted to a CPU 193 through an A/D device 192. In the CPU 193, an average value of a knock signal is found out, and a lower limit value of the knock signal is found out. A correction coefficient K1 multiplying by an average value and which is memorized in a ROM 194, and a correction coefficient K2 multiplying by a lower limit value, are read out, (K2-K1) is multiplied by the lower limit value, the correction coefficient K1 is multiplied by the average value, and a knock judging slice level SL is calculated. A knock signal KS and the slice level SL are compared with each other. In the case of KS<SL, knock lag angle is calculated, and an ignition lag angle quantity is calculated and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a knocking determination device for detecting occurrence of knocking of an engine, and particularly for controlling ignition timing.

[0002]

2. Description of the Related Art The occurrence of knocking of an engine is detected by a knocking sensor attached to an engine block. Since this sensor also detects vibration (noise) other than knocking generated in the engine, knocking and vibration other than knocking are identified in knocking determination.

Conventionally, a knocking signal from a knocking sensor is averaged to obtain an average or the like, which is multiplied by a predetermined correction coefficient and used as a knocking determination level.

Japanese Patent No. 2729329 discloses a knock sensor (101) for detecting knocking of an engine, a peak hold circuit (103) for holding a peak of a knock signal obtained from the sensor, and a knock sensor (103). An A / D converter (104) for A / D converting the output;
A first background (BG) that is increased or decreased based on the result of comparison with the current A / D conversion value (Vp _i ) is set, and the current A / D conversion value (Vp _i ) is set.
/ D converted value large _{(VP i> BG i-1} ) updates the first background (Bg _i) in an increasing direction when, also this A / D conversion value small _{(VP i <BG i- In the case of 1} ), the first background calculating means (A) for updating the first background in the decreasing direction, the current A / D conversion value (VP _i ), and the first background (BG) _i ) multiplied by a predetermined value (K2) (K2 · BG _i );
A / D in comparison with the background (BG _i )
The conversion value is small (VP _i <K2 · BG _i ) and A /
The D-converted value (Vp _i ) is equal to the first background (B
G _i ) when the second background (BG
2 _i ) is updated in the increasing direction, and the current A / D conversion value is small (VP _i <K2 · Bg _i ) and the A / D conversion value (VP _i ) is the first background (Bg). _i )
Is smaller than this value and the current A / D conversion value is large (VP
_i > K2 · B _i ), a second background calculation means (B) for updating the second background in a decreasing direction, and a predetermined knock determination coefficient (K) for the first background. The value is multiplied and compared with the current A / D conversion value. When the current A / D conversion value is large (VP _i > K · BG _i ), the first retard amount (AKCS1) is increased by a constant amount (α). First retardation amount calculating means (C) for causing
A second retardation amount calculating means (D) for converting the difference in the background into a second retardation amount (AKCS2) by a predetermined conversion coefficient (K3), and calculating the second retardation amount from the first and second retardation amounts. There is described a knocking control device including a total retardation amount calculating means (E) for calculating a total retardation amount (AKCS).

[0005]

According to the knocking control device described in the above-mentioned publication, the background BG
BG2i is reduced when the frequency distribution moves in parallel with the knock sensor signal KSi, and the AKCS2 performs the retard control, but the AKCS1 cancels due to the advance operation. BG2i increases when the frequency distribution widens, and AKCS
It is conceivable that the retard amount of No. 2 decreases and AKCS1 performs the retard operation.

The present invention is directed to a knocking determination device and an ignition timing control which can appropriately set a knock determination region even if the knocking occurrence signal frequency distribution becomes parallel movement or divergent, thereby making it possible to perform knock determination appropriately. It is intended to provide a device.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the delay angle control can be performed in response to a change in the frequency distribution without updating the average value BGL obtained by averaging in the increasing or decreasing direction. The lower limit value BGLMIN is obtained by performing a lower limit process on the knocking signal, a process is performed by multiplying the lower limit value by a predetermined correction coefficient, and the knock determination is performed by reflecting the obtained value. It is characterized in that a slice level is calculated.

The present invention provides the following device.

According to the present invention, there is provided a knocking determination apparatus for performing knocking determination using a knocking signal obtained from a knocking detection sensor of an engine. The knocking signal average value processing means, the knocking signal lower limit value processing means, A knocking determination calculating means for calculating a knocking determination slice level based on a value obtained by subtracting the lower limit value from the average value and the lower limit value, and a knocking determination slice level calculated by the knocking determination calculation means and a knocking signal obtained And a comparison means for comparing the knocking determination device with the knocking determination device.

According to the present invention, there is provided an ignition timing control device for controlling an ignition timing using a knocking signal obtained from a knocking detection sensor of an engine, wherein an average value processing means for the knocking signal; When the correction coefficient multiplied by the average value is K1 and the correction coefficient multiplied by the lower limit is K2, the lower limit value is multiplied by (K2−K1), and the average value is K1.
And a knocking determination calculation means for calculating a knocking determination slice level by multiplying the knocking determination slice level calculated by the knocking determination calculation means. Provided is an engine ignition timing control device that calculates an ignition retard amount.

According to the present invention, there is provided a knocking determination method for detecting knocking of an engine and determining knocking using the knocking signal, wherein an average value of the knocking signals is obtained, a lower limit value of the knocking signal is obtained, and the average value is obtained. Provided is a knocking determination method for an engine that determines a knock determination region based on an average value and a lower limit value without updating in an increasing direction or a decreasing direction and that performs a knock determination when a knocking signal belongs to the knock determination region. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram according to an embodiment of the present invention. In the figure, a knock signal A / D value KS11 from a knocking detection sensor (hereinafter referred to as a knock sensor) is subjected to an average value process and a lower limit value process to obtain an average value BGL12 and a lower limit value BGLMIN13, respectively. The correction coefficients K1 and K2 are recorded in the correction coefficient table, and the correction coefficients K1 and K2 are calculated 14 and BG
The calculation 15 of the knock determination slice level SL is performed from L, BGLMIN and K1, K2 according to the following equation.

SL = (BGL−BGLMIN) × K1 + B
GLMIN × K2

The determined knock determination slice level SL
Is compared with knock signal A / D value KS to determine knock determination 1
6KS> SL? Is made. When the determination is YES, the ignition timing retard BETA 17 control is performed.

FIG. 2 shows the knock signal A from the knock sensor signal.
The means for determining the / D value KS is shown. In the figure, an initial gain 22 is reflected on a signal detected by a knock sensor 21, and a band-pass filter BP. The signal of the target frequency is extracted through 23 and one is used as a gate signal.
Others are input to the arithmetic unit CPU 25 via the integration circuit 14,
A / D conversion 26 is performed to determine knock signal A / D value KS27.

FIG. 3 shows an overall configuration diagram. These configurations are well known and need not be described in detail. The air introduced through the filter 1 passes through the intake pipe 2, passes through the intake pipe 2 ′ through the throttle 3, and is introduced into the engine 4 from the valve 7. An idle speed control valve 21 that bypasses the throttle 33 is provided. The fuel in the fuel tank 31 is sucked by the fuel pump 31, injected into the intake pipe 2 ′ from the injector 6, and injected into the engine 4.

The engine exhaust gas is discharged from the exhaust pipe 5 through the valve 8. In such a configuration, the engine control computer 10 sends various signals, for example, an intake air temperature signal from the intake air temperature sensor 26, a throttle opening signal from the throttle opening sensor 24, an exhaust temperature signal from the exhaust temperature sensor 41, and a vehicle speed. The vehicle speed signal from the sensor 25, the crank angle signal from the crank angle sensor 27, and the knocking signal from the knock sensor 22 provided in the engine block are input.

FIG. 4 shows the calculating means of the engine control computer 10. These are well known and need not be described in detail. Knock signal 190 is input to input circuit 191 and A / D device 192 outputs A / D signal.
The data is D-converted and input to the CPU 193. ROM19
4, predetermined information is stored in the RAM 195, and the CPU 1
Information is output to 93. The above-described correction coefficients K1 and K2
Are stored in the ROM 194 in the form of a table. CPU
The result calculated in 193 is taken out as an output value 197 via the output circuit 195.

FIG. 5 is a flowchart showing a slice level calculation flow. First, for each fixed crank angle,
Reading S of knock signal KS for BGLMIN calculation S
51, and a determination S52 of KS <BGLMIN is made. BGLMIN = bglmin (current value) + DB in S52
GLUP # (addition) is calculated, and BGL is calculated in S53.
MIN = KS. Next, BGL calculation is performed. S
At 54, a weighted average is calculated according to the following equation: BGL = KAVE1 # × KS + KAVE2 # × bgl (current value). Next, an SL calculation is performed. Engine speed reading S55, K1, K2 table search S56 is performed, and in S57, SLBUF = (BGL−BGLMIN) × K1 + BGLM.
IN × K2 is calculated, and a weighted average is calculated using this value.
SL = SLBUF × KFLSL1 # + sl (current value) × KF
LSL2 # is calculated, and slice level value SL is determined.
By doing so, the value of the slice level does not change rapidly.

FIG. 6 is a flowchart showing a knock determination flow.

After calculating SL, knock signal KS is read S6
2 and a slice level SL read S63 is performed. From these values, a determination S64 of KS> SL is made, and in the case of YES, the processing is terminated. In the case of NO, the knock retardation is calculated from the calculation of BETA = beta (current value) -DRET # in S65. That is, the predetermined knock retard (DRET #) is subtracted from the current value beta.

Next, a retard limiter process S66 is performed, and the process ends.

FIG. 7 is a flowchart showing an ignition timing calculation flow.

The processing for every 10 ms is shown. The engine speed NDATA is read S71, the load LDATA is read S72, and the ignition map search STD = f (NDA
TA, LDATA) S37 is performed. Knock control amount beta
Reading S74 is performed, BETA = beta + DADV #
The knock control amount retarding process is performed by the calculation in S75. Thereby, the retard limiter process S76 is performed, and the ignition timing calculation ADVS = STD-BETA S77 is performed, and the process ends.

FIG. 8 shows a knock determination area when the present invention is applied to the embodiment of the present invention in relation to the frequency and the knock sensor signal KSi.

FIG. 8A shows a case where data is matched (reference), and a distribution with knock and a distribution without knock are required. The BGL reaches the center where the distribution of the presence or absence of knock is combined. In the figure, the average value BGL and the lower limit value BGL
SL = (BGL−BGLMIN) × K1 + BGLMIN ×
The SL is determined by the calculation of K2, and the knock determination area is specified. This equation is obtained as follows: SL = (K2−K1) × BGLMIN
+ K1 × BGL.

FIG. 8 (2) shows a case where the distribution has shifted on average. Since BGLMIN is adopted, the knock determination area is appropriately set, and the knock determination is appropriately performed.

FIG. 8C shows a case where the distribution is widened. It can be seen that the knock determination area is appropriately set because BGLMIN is adopted.

FIG. 8D shows the case where the distribution is divergent and moves in parallel. It can be seen that the knock determination area is appropriately set because BGLMIN is adopted.

FIG. 9 shows, as a comparative example, a judgment method when a change in BGL is indicated. Each figure corresponds to each figure in FIG. In FIG. 9 (2), BG2i becomes smaller and AK2
Although retard control is performed by CS2, AKCS1 is retarded because of the retard operation, and the knock determination area becomes uncertain and knock determination is impossible. In FIG. 9 (3), BG2i increases, the retard amount of AKCS2 decreases, and AKCS1 performs a retard operation. For this reason, an erroneous determination that knock is present may occur.

[0032]

According to the present invention, BGLMIN is determined,
The calculation is performed by using the correction coefficients K1 and K2, and the knock determination area can be appropriately determined for determining the slice level SL, so that erroneous determination does not occur in the knock determination. Therefore, appropriate ignition timing control becomes possible.

[Brief description of the drawings]

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

FIG. 2 is a detailed view of a part of FIG.

FIG. 3 is an overall schematic configuration diagram.

FIG. 4 is an explanatory diagram showing the contents of an engine control computer.

FIG. 5 is a flowchart of a slice level calculation.

FIG. 6 is a flowchart of a knock determination.

FIG. 7 is a flowchart of an ignition timing calculation.

FIG. 8 is an operation explanatory view showing an example of the present invention in a distribution.

FIG. 9 is an operation explanatory view showing a comparative example.

[Explanation of symbols]

11: Knock signal A / D value KS, 12: Average value processing BG
L, 13: lower limit processing BGLMIN, 14: correction coefficient calculation K1, K2, 15: knock determination slice level calculation,
16 ... Knock determination KS> SL? , 17: ignition timing retard B
ETA.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Mamoru Nemoto 2477 Takaba, Hitachinaka-shi, Ibaraki Prefecture Inside Hitachi Car Engineering Co., Ltd. (72) Inventor Hisahiro Oba 2477 Takaba, Hitachinaka-shi, Ibaraki Prefecture Hitachi Car Engineering Co. F term (reference) 3G022 DA02 EA02 GA01 GA05 GA13 3G084 BA17 DA04 DA27 DA38 EA11 EB08 EB22 EB25 EC04 FA25 FA33 FA38

Claims (3)

[Claims] 1. A knocking determination device that performs knocking determination using a knocking signal obtained from a knocking detection sensor of an engine, wherein: an average value processing means for the knocking signal; a lower limit value processing means for the knocking signal; Knocking determination calculating means for calculating a knocking determination slice level based on a value obtained by subtracting the lower limit value from the value and the lower limit value; and a knocking determination slice level calculated by the knocking determination calculation means and the obtained knocking signal. A knocking determination device comprising: a comparison unit for comparing. 2. An ignition timing control device for controlling an ignition timing using a knocking signal obtained from a knocking detection sensor of an engine, wherein: an average value processing means for the knocking signal; and a lower limit value processing means for the knocking signal. When the correction coefficient multiplied by the average value is K1 and the correction coefficient multiplied by the lower limit is K2, the lower limit value is multiplied by (K2−K1), and the average value is multiplied by K1 to knock. Knocking determination calculation means for calculating a determination slice level, wherein the ignition delay amount is determined based on knocking determination from a knocking determination device that performs knocking determination using the knocking determination slice level calculated by the knocking determination calculation means. An ignition timing control device for performing calculations. 3. A knocking determination method for detecting knocking of an engine and performing knocking determination using the knocking signal, comprising: determining an average value of the knocking signal; determining a lower limit value of the knocking signal; Alternatively, an ignition timing control device characterized in that a knock determination region is determined based on an average value and a lower limit value without updating in a decreasing direction, and a knock determination is performed when a knock signal belongs to the knock determination region.