KR20000042284A - Apparatus for and method of controlling ignition timing using knock sensor in automobile - Google Patents

Abstract

PURPOSE: An apparatus for and method of controlling an ignition timing using a knock sensor are provided to prevent a repeated occurrence of knock and achieve an optimized engine output while allowing advancement or retardation of the ignition timing of engine according to the rotation speed and load of the engine. CONSTITUTION: An apparatus for controlling an ignition timing comprises a knock window setting unit for setting a begging value and a duration value of the knock window according to a rotation speed of an engine and controlling an integrator, a knock frequency setting unit for setting a knock window filtering frequency band and controlling a band-pass filter, a gain control unit for controlling an amplifier by setting an amplification degree for detecting a normal engine noise by each rotation speed of engine and load, a knock determination unit for receiving the normal engine noise signal and the estimated digital knock signal, estimating a knock energy level, determining whether to knock by comparing the estimated knock energy level with a reference level, and advancing or retarding an ignition timing of the engine, and an engine noise setting unit for setting a normal engine noise if a knock is not occurred and applying the normal engine noise to the gain control unit and the knock determination unit.

Description

Ignition timing control device and method using knock sensor in vehicle

The present invention relates to ignition timing control using a knock sensor in a vehicle. In particular, after the knock energy level corresponding to the engine rotation speed and the load is measured using the knock signal measured by the knock sensor, the result is compared with a reference knock energy level. The present invention relates to an ignition timing control device and method using a knock sensor in a vehicle to advance or perceive an ignition timing of an engine.

In general, in the engine of a vehicle, a mixed gas in which fuel and air are mixed is ignited by a vaporizer by an external flame, and an electric spark generated by an ignition device is used as the external flame.

The ignition device generates spark energy capable of igniting the mixed gas instantaneously according to the spark timing set in advance under any driving conditions of the engine. That is, the ignition device must have a function to control the ignition timing according to the rotational speed of the engine and the load variation.

On the other hand, the ignition timing that varies according to the engine condition or operating conditions in the ignition device is closely related to the harmful emissions, fuel consumption rate and the knocking trend. The most important correlation among them is the engine's knocking trend. If the timing is too early, the ignition pressure wave causes the mixed gas to ignite before reaching the normal flame surface, resulting in an abnormal combustion, leading to an increase in the maximum pressure and accompanied by intense pressure fluctuations.

In this way, a metallic blow sound generated when a piston strikes a cylinder wall due to a violent pressure fluctuation is called knock, which is clearly heard when the engine speed of the vehicle is low, but when the engine speed increases, the knock Dims. However, even knocks of this kind can damage the engine, so the fuel and the ignition timing must be properly balanced to prevent knocking.

Therefore, as a control device for adjusting the ignition timing, there are a centrifugal type and a vacuum advancing device. The centrifugal type controls the ignition timing according to the rotational speed of the engine, and the vacuum type mainly controls the ignition timing according to the engine load variation. do. In addition, in the electronic ignition device currently used, the engine temperature and the mixing ratio, etc., in addition to the rotational speed and the load of the engine also affect the ignition timing. These ignition timing control variables are mechanically or electrically connected to determine the ignition timing.

In order to determine the ignition timing, information on the rotation angle of the crankshaft is required. The information is transmitted directly to the distributor drive shaft by an appropriate mechanism when using a mechanical distributor, and in the electronic case, the rotation angle of the crankshaft or camshaft. Information about the electronic signal is transmitted to the electronic controller in order to calculate the ignition timing. That is, the vacuum and centrifugal advancing devices are mechanically connected to each other so that two ignition advance amounts are summed to change the ignition timing.

However, the knock is affected by the change in the atmospheric condition (humidity, temperature, atmospheric pressure, etc.) according to the season, so first, after calculating the amount of ignition of the knock generated by the electronic controller, the change of the atmospheric state To compensate the ignition advance by retarding and input it into the calibration table of the electronic control device, but conventionally perceives the compensation margin for change in the atmospheric state uniformly. If the amount of advance is large, knocking will be severe and damage the engine.

Thus, the engine output is usually reduced by compensating for the worst change in the standby state and perceiving the ignition advance.

As described above, conventionally, only the ignition timing control function that uniformly perceives the amount of ignition advance is performed in consideration of the worst condition for the change in the standby state when knocking occurs by comparing the knock signal measured by the knock sensor with a preset knock condition. As a result, the output of the engine was reduced.

The present invention has been made to solve the above problems, the object of which is to measure the knock energy level corresponding to the engine rotation speed and load of the vehicle, and according to the result of comparing the measured knock energy level and the reference knock energy level By determining whether or not to knock, by advancing or retarding the ignition timing of the vehicle engine in accordance with the engine rotation speed and the load, it is possible to prevent the knock occurs repeatedly and to optimize the output of the engine.

A feature of the present invention for achieving the above object is a vehicle ignition timing control device comprising a knock sensor for detecting the knock generated in the cylinder, an amplifier, a band filter, a rectifier, an integrator and an analog-digital converter. A knock window setting unit for controlling the integrator by setting a start value and a sustain value of the knock window according to an engine rotation speed based on a top dead center; A knock frequency setting unit configured to control the band filter by setting a knock window filtering frequency band for detecting an engine rotation speed and a knock frequency generated for each load; A gain controller configured to control the amplifier by setting an amplification degree for constantly detecting normal engine noise for each engine speed and load; The knock energy level is measured by receiving the normal engine noise signal and the measured digital knock signal. Then, the measured knock energy level and the reference knock energy level are compared to determine whether the knock is performed, and the reference knock energy level is determined according to the determined result. A knock judging unit which performs a function of advancing or perceiving an ignition timing of the engine while updating; The apparatus further includes an engine noise setting unit for setting normal engine noise when knocking does not occur and applying the gain to the gain control unit and the knock determination unit.

According to another aspect of the present invention, there is provided a method of controlling an ignition timing using a knock sensor in a vehicle, comprising: a first step of detecting a knock signal generated by a pressure change caused by a combustion explosion force in a cylinder; A second step of converting the detected knock signal into a digital knock signal after processing the analog signal according to the engine rotation speed and the load of the vehicle; A third step of measuring a knock energy level corresponding to the engine speed and the load by using the knock signal and a normal engine noise signal; A fourth step of comparing the measured knock energy level with a predetermined reference knock energy level and checking whether the knock energy level is within an allowable knock error range; A fifth process of returning to the first process and performing a repetitive operation when within a permitted knock error range; A sixth step of advancing or perceiving the ignition timing of the engine by using the updated knock energy level after updating the measured knock energy level to a new reference knock energy level if it is not within the allowable knock error range in the fourth process. To include the process.

1 is a block diagram of a ignition timing control device using a knock sensor in a vehicle according to the present invention.

FIG. 2 is a view showing a knock window setting state of the knock window setting unit in FIG. 1; FIG.

3 is a view showing a window frequency band setting state of the knock frequency setting unit in FIG.

4 is an operation flowchart for implementing a ignition timing control method using a knock sensor in a vehicle according to the present invention.

Explanation of symbols on the main parts of the drawings

11: knock sensor 12: amplifier

13: band filter 14: rectifier

15: integrator 16: knock window setting unit

17: knock frequency setting unit 18: gain control unit

19: engine noise setting unit 20: analog / digital conversion unit

21: knock discrimination unit ASP: analog signal processing unit

DSP: Digital Signal Processing Unit

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

An ignition timing control apparatus using a knock sensor in a vehicle according to the present invention includes a knock sensor 11, an analog signal processing unit (ASP), and a digital signal processing unit (DSP) as shown in FIG. 1. Digital signal processing (ASP), which includes an amplifier 12, a bandpass filter 13, a rectifier 14 and an integrator 15, and a corresponding digital signal processing unit (DSP). ) Is the knock window setting unit 16, the knock frequency setting unit 17, the gain control unit 18, the engine noise setting unit 19, the analog / digital converter 20 and the knock determination unit 22 )

The knock sensor 11 is installed on the outer wall between the cylinder and the cylinder, and applies the knock signal generated by the pressure fluctuation caused by the combustion explosion force in the cylinder to the amplifier 12, and the amplifier 12 knocks. The knock signal applied from the sensor 11 is amplified to a predetermined level under the control of the gain control unit 18 and applied to the band filter 13.

The band filter 13 filters the knock signal amplified and applied by the amplifier 12 according to the control of the knock frequency setting unit 17 and passes only the frequency of a predetermined band to the rectifier 14 to apply the rectifier 14. 14 rectifies the knock signal filtered by the band filter 13 and applies it to the integrator 15.

The integrator 15 integrates the knock signal rectified by the rectifier 15 under the control of the knock window setting unit 16 and applies it to the analog / digital converter 20 of the digital signal processor DSP. The knock window setting unit 16 includes a knock window size, that is, a knock window, based on a top dead center (TDC) as shown in FIG. 2. Integrator 15 is controlled by setting the start value (WB; Window Beginning) and the duration value (WD;

The knock frequency setting unit 17 sets the knock window filtering frequency band (WFB) for detecting the knock frequency generated for each engine rotation speed and load, as shown in FIG. The gain control unit 18 controls the amplifier 12 by setting an amplification degree for constantly detecting normal engine noise for each engine rotation speed and load when no knock occurs to be compared with the knock signal at the time of knock generation. To control.

The engine noise setting unit 19 sets normal engine noise when no knock occurs and applies the gain to the gain control unit 18 and the knock determination unit 21, and the analog / digital conversion unit 20 supplies an integrator ( The analog knock signal integrated in step 15) is converted into a digital knock signal and applied to the knock determination unit 21.

The knock determination unit 21 measures the knock energy level by using the normal engine noise signal applied from the engine noise setting unit 19 and the measured digital knock signal applied from the analog / digital converter 20. By comparing the measured knock energy level and the reference knock energy level, whether or not the knock is determined, the reference knock energy level is updated according to the determined result, and the function of advancing or perceiving the ignition timing of the engine is performed.

The ignition timing control operation using the knock sensor in the vehicle according to the present invention configured as described above will be described with reference to FIG. 4.

First, the knock sensor 11 is installed on the outer wall between the cylinder and the cylinder of the vehicle engine, and is detected by the knock sensor 11 generated by the pressure fluctuation caused by the combustion explosion force in the cylinder (step S41). The signal is applied to the digital signal processing unit DSP through the analog signal processing unit ASP in the electronic controller. When this is described in detail, when the knock signal detected by the knock sensor 11 is applied to the amplifier 12, the corresponding signal is applied. The amplifier 12 amplifies the knock signal applied from the corresponding knock sensor 11 to a predetermined level according to the amplification degree control of the gain control unit 18 in order to detect the engine rotational speed and load uniformly, and then amplifies the knock signal. Is applied to the band filter 13.

In this case, since the knock frequency of each engine rotation speed and load is changed in the band filter 13, only the knock frequency of the engine is passed, and the knock signal amplified and applied to detect the knock frequency corresponding to the engine rotation speed and load is detected. Filtering is performed according to the filtering frequency band control of the knock frequency setting unit 17 to apply only the knock frequency of the predetermined band to the rectifier 14. The rectifier 14 filters noise included in the filtered knock signal of the predetermined frequency band. In order to eliminate the knock signal, the rectified knock signal is applied to the integrator 15.

Then, since the size of the knock window is different according to the engine rotation speed, the integrator 15 integrates to obtain a knock signal that can be compared with the same size in all areas, but the knocked window setting unit 16 Integrate to the knock window size set according to the engine rotation speed based on the top dead center, and apply the integrated knock signal to the analog / digital converter 20 of the digital signal processor DSP. do.

The analog knock signal measured by the knock sensor 11 applied through the process is converted into the knock signal of the digital form by the analog / digital converter 20 and applied to the knock discriminator 21. At this time, the engine noise setting unit 19 sets the normal engine noise when the knock does not occur in response to the current engine speed and the load, and applies the engine noise to the knock determination unit 21. 21 measures the knock energy level corresponding to the engine speed and the load of the current vehicle by using the knock signal applied from the analog / digital converter 20 and the engine noise applied from the engine noise setting unit 19. Subsequently (step S42), the measured knock energy level is compared with the predetermined reference knock energy level (step S43).

At this time, as a result of comparing the measured knock energy level and the reference knock energy level, it is checked whether the corresponding knock energy level difference value is within the allowable knock error range (step S44), and if it is within the allowable knock error range, step S41. By returning to and performing the repetitive operation, the ignition timing of the engine is controlled using the reference knock energy level.

However, in step S44, if it is not within the allowable knock error range, the knock determination unit 21 deletes the reference knock energy level and updates the measured knock energy level with a new reference knock energy level (step S45), by advancing or retarding the ignition timing of the engine using the updated knock energy level (step S46), depending on the engine speed and load affected by the fuel characteristics and the standby state of the vehicle. Corresponding ignition timing control becomes possible, which prevents knocking repeatedly and optimizes engine output.

As described above, the present invention measures the knock energy level corresponding to the engine rotation speed and the load of the vehicle, and makes it possible to determine whether to knock based on a result of comparing the measured knock energy level with a reference knock energy level. The engine's ignition timing can be advanced or perceived according to the engine speed and load, thereby preventing knocks from occurring repeatedly and optimizing the output of the engine.

Claims (2)

In a vehicle ignition timing control device comprising a knock sensor for detecting knocks generated from a cylinder, an amplifier, a bandpass filter, a rectifier, an integrator, and an analog-to-digital converter, A knock window setting unit configured to control the integrator by setting a start value and a sustain value of the knock window according to the engine rotation speed based on a top dead center; A knock frequency setting unit configured to control the band filter by setting a knock window filtering frequency band for detecting an engine rotation speed and a knock frequency generated for each load; A gain controller configured to control the amplifier by setting an amplification degree for constantly detecting normal engine noise for each engine speed and load; The knock energy level is measured by receiving the normal engine noise signal and the measured digital knock signal. Then, the measured knock energy level and the reference knock energy level are compared to determine whether the knock is performed, and the reference knock energy level is determined according to the determined result. A knock judging unit which performs a function of advancing or perceiving an ignition timing of the engine while updating; An engine ignition timing control device using a knock sensor in a vehicle, characterized in that it further comprises an engine noise setting unit for setting normal engine noise when knocking does not occur and applying it to the gain control unit and the knock determination unit. In the ignition timing control method using a knock sensor in a vehicle, A first step of detecting a knock signal generated in response to a pressure fluctuation caused by a combustion explosion force in the cylinder; A second step of converting the detected knock signal into a digital knock signal after processing the analog signal according to the engine rotation speed and the load of the vehicle; A third step of measuring a knock energy level corresponding to the engine speed and the load by using the knock signal and a normal engine noise signal; A fourth step of comparing the measured knock energy level with a predetermined reference knock energy level and checking whether the knock energy level is within an allowable knock error range; A fifth process of returning to the first process and performing a repetitive operation when within a permitted knock error range; A sixth step of advancing or perceiving the ignition timing of the engine by using the updated knock energy level after updating the measured knock energy level to a new reference knock energy level if it is not within the allowable knock error range in the fourth process. Ignition timing control method using a knock sensor in a vehicle comprising a process.