Automotive engine ignition system diagnostic and control system and method

Abstract

The application discloses a diagnosis and control system and method for an automobile engine ignition system, and particularly relates to the technical field of engine ignition diagnosis and control, and comprises a knock signal processing module, which extracts a knock characteristic frequency signal through a band-pass filtering algorithm; an ignition angle dynamic adjustment module, which is used for executing a retreat angle immediately when knock is detected; a transient condition correction module, which corrects a knock limit value according to a rotational speed variation and a throttle opening variation; and a diagnosis module, which judges sensor abnormalities by monitoring a standard deviation of a knock signal, and triggers a sensor fault alarm according to the sensor abnormalities. The application can improve the knock detection precision and the ignition control response speed, reduce the engine damage risk, and is suitable for knock suppression and power optimization under different conditions.

Description

Technical Field

[0001] This invention relates to the field of engine ignition diagnosis and control technology, and more specifically, to a diagnostic and control system and method for automotive engine ignition systems. Background Technology

[0002] During engine operation, knocking can lead to decreased power, increased fuel consumption, and even engine damage. Therefore, accurate knock detection and ignition control are crucial. Existing technologies have the following main drawbacks: Limitations of signal processing: Traditional knock signal filtering algorithms do not dynamically adjust the center frequency in conjunction with engine physical parameters (such as cylinder bore), resulting in poor signal matching between different engine models; gain control mostly uses a fixed amplification factor, which cannot take into account the signal resolution at high and low speeds.

[0003] Ignition control lag: A single retraction strategy is difficult to balance knock response speed and power stability. Fast retraction control lacks a phased recovery mechanism, and slow retraction control does not consider the coupling effect of load and speed, resulting in insufficient system robustness.

[0004] Misjudgment of transient conditions: Knock limits cannot be corrected in real time under transient conditions (such as rapid acceleration and deceleration), which can easily lead to false alarms or missed detections due to signal fluctuations, affecting driving smoothness.

[0005] Lack of fault diagnosis: The existing system lacks a knock sensor status monitoring mechanism, which makes it impossible to detect sensor aging or failure in a timely manner, posing a safety hazard.

[0006] To address the aforementioned issues, this invention provides an ignition system that integrates dynamic filtering, multi-level back angle adjustment, transient correction, and fault diagnosis. Through algorithm optimization and hardware collaboration, it achieves accurate detection and adaptive control of knock. Summary of the Invention

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides a diagnostic and control system and method for an automotive engine ignition system to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a diagnostic and control system for an automotive engine ignition system, comprising: The detonation signal processing module extracts the detonation characteristic frequency signal through a bandpass filtering algorithm. The expression for the filtering algorithm is as follows: ; in, Using the center frequency as the input, different orders are calculated by inputting the engine cylinder bore. value; The cutoff frequency; For quality factor; The ignition angle dynamic adjustment module is used to immediately adjust the ignition angle when knock is detected; The transient operating condition correction module corrects the knock limit based on changes in engine speed and throttle opening.

[0009] Preferably, it also includes a diagnostic module, which determines sensor abnormalities by monitoring the standard deviation of the knock signal and triggers a sensor fault alarm based on the sensor abnormalities.

[0010] Preferably, the knock signal processing module includes a gain control unit, which adjusts the speed according to the rotational speed. The gain control logic is as follows: (The code divides the region into high-gain and low-gain zones.) ; in, The high-gain range speed threshold, This is the amplification factor in the low-gain range, with a default value of 4.

[0011] Preferably, the detonation signal processing module further includes a detonation integral intensity calculation unit, which is used to integrate the filtered and amplified detonation signal to obtain the detonation integral intensity. The calculation formula is: ; in, This is the original detonation signal. This is the gain coefficient. and This represents the time boundary of the detonation window.

[0012] Preferably, the detonation integral intensity calculation unit further performs steady-state and transient filtering on the detonation integral intensity, and the filtering algorithm is as follows: ; in, Here are the filter coefficients, under steady-state conditions. , Transient operating conditions , , This is the filtered value from the previous moment.

[0013] Preferably, when the ignition angle dynamic adjustment module detects detonation, it immediately performs an angle reduction, and the angle reduction logic is as follows: ; ; When the receding angle recovers, it is done in steps. ( ) and interval Gradually recovering, The range is 0.125-0.25s; among which, For the ignition point of the previous moment, For the step size of the receding angle, The range is 1-2°; Furthermore, additional back angle compensation is added during severe knocking: ; When the receding angle exceeds ( When this occurs, the accelerated recovery logic is initiated, with a recovery step size of [value missing]. ( ).

[0014] Preferably, the ignition angle dynamic adjustment module includes a learning unit based on speed and load division, used to store the re-ignition angle learning value, and the slow re-ignition logic is as follows: ; ; Recovery by step size ( Slow recovery; among them, To slow down the ignition timing, The slow decay value from the previous moment. The value range is 8-12°.

[0015] Preferably, the transient condition correction module adjusts the speed according to the change in rotational speed. and throttle opening change The correction formula for the knock limit is: ; in, This is the correction factor for speed variation. This is the correction factor for throttle opening change. This is the initial detonation limit. This is the revised knock limit.

[0016] A method for diagnosing and controlling an automotive engine ignition system includes the following steps: S1: Extract the detonation characteristic frequency signal using a bandpass filtering algorithm; S2: Immediately execute the recoil angle when a detonation is detected based on the detonation characteristic frequency signal; S3: Corrects the knock limit based on changes in engine speed and throttle opening; S4: The sensor is identified by monitoring the standard deviation of the knock signal, and a sensor fault alarm is triggered based on the sensor abnormality. The standard deviation of the detonation signal in S4 is calculated as follows: ; when or When this occurs, a sensor fault alarm is triggered, in which... For the first Sub-detonation integral intensity The mean, The number of samples.

[0017] Preferably, it also includes dynamic calibration of the knock limit, dividing the operating conditions into three ranges: high, medium, and low, based on the engine load, with knock limits for each range. The expression is: ; in, For high-load range limits, the recommended value is 90%-100% of the load when the throttle is fully open; The value used as the boundary between medium and low loads is taken as follows: The median of the initial detonation load.

[0018] The technical effects and advantages of this invention are as follows: 1. By using bandpass filtering algorithm and gain control technology, combined with engine cylinder bore calculation center frequency and dynamic adjustment of signal amplification factor, non-knock frequency interference is effectively suppressed, the knock signal detection accuracy across the entire speed range is improved, and the problems of high-speed signal overload and low-speed signal weakness are avoided.

[0019] 2. Through a multi-stage ignition angle adjustment mechanism, it can not only quickly suppress knocking and reduce power loss, but also adaptively compensate for long-term factors such as engine aging and fuel quality differences, thereby improving system robustness.

[0020] 3. The knock limit is corrected in real time based on the changes in engine speed and throttle opening to avoid false knocking or missed detection due to fixed limits under transient conditions, thereby improving control accuracy under complex conditions.

[0021] 4. By monitoring the standard deviation of the detonation signal, sensor abnormalities can be identified. A threshold can be set, and an alarm can be triggered when the threshold is exceeded, thereby realizing real-time monitoring of the detonation detection link and preventing misjudgment or missed detection due to sensor failure. Attached Figure Description

[0022] Figure 1 This is the method flow of the present invention. Detailed Implementation

[0023] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The present invention provides a diagnostic and control system for an automotive engine ignition system, comprising: The detonation signal processing module extracts the detonation characteristic frequency signal through a bandpass filtering algorithm. The expression for the filtering algorithm is as follows: ; in, Using the center frequency as the input, different orders are calculated by inputting the engine cylinder bore. value; The cutoff frequency; For quality factor; The ignition angle dynamic adjustment module is used to immediately adjust the ignition angle when knock is detected; The transient operating condition correction module corrects the knock limit based on changes in engine speed and throttle opening.

[0025] In practice, a bandpass filtering algorithm is used to separate the knock characteristic frequencies and suppress non-knock frequency interference. The passband width is adjusted using a quality factor to ensure signal purity. The ignition angle dynamic adjustment module adjusts the ignition angle back when knock is detected, and the transient condition correction module adjusts the knock limit in real time based on changes in engine speed and throttle opening. This enables accurate extraction of the knock signal and avoids misjudgment. Dynamic adjustment of the ignition angle provides a rapid response to knock, improving control robustness under transient conditions and reducing the risk of engine damage.

[0026] It also includes a diagnostic module that monitors the standard deviation of the knock signal to determine sensor abnormalities and triggers a sensor fault alarm based on the abnormality.

[0027] In practice, the diagnostic module monitors signal fluctuations by calculating the standard deviation of the detonation signal. By setting a threshold, an alarm is triggered when the threshold is exceeded, thereby enabling real-time diagnosis of detonation sensor malfunctions, preventing false or missed detonation detections due to sensor failure, and improving system reliability.

[0028] The knock signal processing module includes a gain control unit, which adjusts the speed according to the rotational speed. The gain control logic is as follows: (The code divides the region into high-gain and low-gain zones.) ; in, The high-gain range speed threshold, This is the amplification factor in the low-gain range, with a default value of 4.

[0029] In practice, it depends on the rotational speed. Divide the gain range, high speed ( ) Uses a fixed gain of 4, low speed ( Adjustable gain is used Optimize signal resolution at different speeds to avoid signal overload at high speeds and weak signals at low speeds, thereby improving the detection accuracy of knock signals across the entire speed range.

[0030] The detonation signal processing module further includes a detonation integral intensity calculation unit, which is used to integrate the filtered and amplified detonation signal to obtain the detonation integral intensity. The calculation formula is: ; in, This is the original detonation signal. This is the gain coefficient. and This represents the time boundary of the detonation window.

[0031] In practice, the detonation window is calculated by integration. and The signal energy within the time domain is used to quantify the detonation intensity, thereby transforming the time domain signal into a quantifiable intensity index, providing a data basis for determining the detonation level.

[0032] The detonation integral intensity calculation unit also performs steady-state and transient filtering on the detonation integral intensity. The filtering algorithm is as follows: ; in, Here are the filter coefficients, under steady-state conditions. , Transient operating conditions , , This is the filtered value from the previous moment.

[0033] In practice, a first-order inertial filtering algorithm is used, with steady-state filtering coefficients. Smoothing signal fluctuations, transient filter coefficient It can quickly track intensity changes to suppress steady-state noise interference, while also promptly reflecting sudden changes in detonation intensity under transient conditions, thus balancing detection sensitivity and anti-interference capability.

[0034] When the ignition angle dynamic adjustment module detects detonation, it immediately performs an angle reduction. The angle reduction logic is as follows: ; ; When the receding angle recovers, it is done in steps. ( ) and interval Gradually recovering, The range is 0.125-0.25s; among which, For the ignition point of the previous moment, For the step size of the receding angle, The range is 1-2°; Furthermore, additional back angle compensation is added during severe knocking: ; When the receding angle exceeds ( When this occurs, the accelerated recovery logic is initiated, with a recovery step size of [value missing]. ( ).

[0035] In practice, the fast-rewind logic uses a step size. and threshold Rapid retreat angle, recovery in steps and interval Gradual recovery, with compensation added during severe knock shocks. Exceeding the threshold It accelerates recovery in time, thereby quickly curbing the development of knock and avoiding engine damage; it restores the ignition timing in stages, reducing power loss and improving driving smoothness.

[0036] The ignition angle dynamic adjustment module includes a learning unit based on engine speed and load, used to store the re-ignition angle learning value. The slow re-ignition logic is as follows: ; ; Recovery by step size ( Slow recovery; among them, To slow down the ignition timing, The slow decay value from the previous moment. The value range is 8-12°.

[0037] In practice, the slow-retreat logic divides learning units based on rotational speed and load, with a step size... Cumulative setback angle, maximum setback angle The value range is 8-12°, with a slow recovery step size. By compensating for the tendency of knocking caused by long-term factors such as engine aging and fuel quality differences, the system improves its robustness by adaptively adjusting the ignition angle through a learning mechanism.

[0038] The transient condition correction module adjusts based on the speed change. and throttle opening change The correction formula for the knock limit is: ; in, This is the correction factor for speed variation. This is the correction factor for throttle opening change. This is the initial detonation limit. This is the revised knock limit.

[0039] In practice, the transient condition correction module adjusts the knock limit based on the changes in engine speed and throttle opening, dynamically adapting to sudden changes in operating conditions. This avoids false shutdowns or missed detections caused by fixed limits under transient conditions, and improves the knock control accuracy under complex operating conditions.

[0040] like Figure 1 As shown, the present invention provides a diagnostic and control method for an automotive engine ignition system, comprising the following steps: S1: Extract the detonation characteristic frequency signal using a bandpass filtering algorithm; S2: Immediately execute the recoil angle when a detonation is detected based on the detonation characteristic frequency signal; S3: Corrects the knock limit based on changes in engine speed and throttle opening; S4: The sensor is identified by monitoring the standard deviation of the knock signal, and a sensor fault alarm is triggered based on the sensor abnormality. The standard deviation of the detonation signal in S4 is calculated as follows: ; when or When this occurs, a sensor fault alarm is triggered, in which... For the first Sub-detonation integral intensity The mean, The number of samples.

[0041] In practice, the stability of the sensor signal is determined by calculating the homogeneity and standard deviation of the detonation integral intensity. An alarm is triggered when an anomaly occurs, thus realizing full-cycle monitoring of the detonation detection link, timely detection of sensor faults, and ensuring the safe operation of the system.

[0042] It also includes dynamic calibration of knock limits, dividing the operating conditions into high, medium, and low ranges based on engine load, with knock limits for each range. The expression is: ; in, For high-load range limits, the recommended value is 90%-100% of the load when the throttle is fully open; The value used as the boundary between medium and low loads is taken as follows: The median of the initial detonation load.

[0043] In practice, it depends on the engine load. Divide the data into three ranges: high, medium, and low, and set limits for each range. , , The limits in the high-load area are appropriately relaxed to match the aggressive ignition strategy, thereby optimizing the knock detection sensitivity under different loads. The high-load area takes into account both power and safety, while the low-load area avoids misjudgment.

[0044] Specifically, the system hardware architecture includes: The sensor module deploys a knock sensor to collect cylinder block vibration signals and outputs a raw voltage signal. (0-5V); ECU control unit: integrates knock signal processing module, ignition angle dynamic adjustment module, transient condition correction module and diagnostic module, and uses FC33 chip to implement algorithms such as bandpass filtering, gain control and integral calculation.

[0045] Actuator: The electronic igniter adjusts the ignition advance angle according to the ECU command to achieve fast retarder and slow retarder control.

[0046] Processing detonation signals specifically includes the following steps: Bandpass filtering: Input engine cylinder bore data and calculate the third-order center frequency. , , Configure the chip's filter coefficients; Gain control: Real-time monitoring of rotational speed ,when Enable high gain Otherwise, use low gain. .

[0047] Integration and Filtering: In the Knock Window and Integrating the signal internally yields Then calculate using steady-state / transient filter coefficients. .

[0048] The ignition angle adjustment logic includes: Fast Rewind Control: Execute immediately upon detecting knock. until ; during recovery Step length, Gradual pullback at intervals, superimposed during severe knockout. compensate; Slow-rewind control: Learning units are divided according to speed and load boundaries, and knock is triggered each time. The maximum retreat angle is 12°, and the recovery step size is 0.01°.

[0049] When correcting for instantaneous operating conditions, the following should be included: Operating condition determination: When the rate of change of speed or throttle opening change rate When this occurs, it is determined to be a transient operating condition; Limit correction: based on Adjust the limits, among which , Calibration was achieved through vehicle drivability and high-temperature testing.

[0050] The system diagnostic mechanism is as follows: Sensor diagnostics: Detonation integral intensity is collected every 60 seconds. Calculate the mean and standard deviation ,like or When this happens, the fault light alarm will be triggered; Limit verification: Verification of various operating conditions using the Slew ignition angle test (adding 3-5° to trigger knock, deducting 3-5° to eliminate knock). Whether it is within the calibration range, to ensure the reasonableness of the limit value.

[0051] Finally, bench calibration and vehicle testing were conducted. The ignition angle was adjusted to the knock critical point within the full speed and full load range. The knock window start angle, width, and weight of each center frequency were recorded to ensure that the window covers the knock signal and avoids noise. The fast or slow retraction logic and transient correction effect were verified in extreme environments such as summer high temperature and high altitude to ensure that the ignition angle retraction angle and recovery characteristics meet the design requirements.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A diagnostic and control system for an automotive engine ignition system, characterized in that, include: The detonation signal processing module extracts the detonation characteristic frequency signal through a bandpass filtering algorithm. The expression for the filtering algorithm is as follows: ； in, Using the center frequency as the input, different orders are calculated by inputting the engine cylinder bore. value; The cutoff frequency; For quality factor; The ignition angle dynamic adjustment module is used to immediately adjust the ignition angle when knock is detected; The transient operating condition correction module corrects the knock limit based on changes in engine speed and throttle opening.

2. The automotive engine ignition system diagnostic and control system according to claim 1, characterized in that, It also includes a diagnostic module that monitors the standard deviation of the knock signal to determine sensor abnormalities and triggers a sensor fault alarm based on the abnormality.

3. The automotive engine ignition system diagnostic and control system according to claim 1, characterized in that, The knock signal processing module includes a gain control unit, which adjusts the speed according to the rotational speed. The gain control logic is as follows: (The code divides the region into high-gain and low-gain zones.) ； in, The high-gain range speed threshold, This is the amplification factor in the low-gain range, with a default value of 4.

4. The automotive engine ignition system diagnostic and control system according to claim 1, characterized in that, The detonation signal processing module further includes a detonation integral intensity calculation unit, which is used to integrate the filtered and amplified detonation signal to obtain the detonation integral intensity. The calculation formula is: ； in, This is the original detonation signal. This is the gain coefficient. and This represents the time boundary of the detonation window.

5. The automotive engine ignition system diagnostic and control system according to claim 4, characterized in that, The detonation integral intensity calculation unit also performs steady-state and transient filtering on the detonation integral intensity. The filtering algorithm is as follows: ； in, For the filter coefficients, under steady-state conditions , Transient operating conditions , , This is the filtered value from the previous moment.

6. The automotive engine ignition system diagnostic and control system according to claim 1, characterized in that, When the ignition angle dynamic adjustment module detects detonation, it immediately performs an angle reduction. The angle reduction logic is as follows: ； ； When the receding angle recovers, it is done in steps. ( ) and interval Gradually recovering, The range is 0.125-0.25s; among which, For the ignition point of the previous moment, For the step size of the receding angle, The range is 1-2°; Furthermore, additional back angle compensation is added during severe knocking: ； When the receding angle exceeds ( When this occurs, the accelerated recovery logic is initiated, with a recovery step size of [value missing]. ( ).

7. The automotive engine ignition system diagnostic and control system according to claim 1, characterized in that, The ignition angle dynamic adjustment module includes a learning unit based on engine speed and load, used to store the re-ignition angle learning value. The slow re-ignition logic is as follows: ； ； Recovery by step ( Slow recovery; among them, For slow retraction of the ignition tip, The slow decay value from the previous moment. The value range is 8-12°.

8. The diagnostic and control system and method for an automotive engine ignition system according to claim 1, characterized in that, The transient condition correction module adjusts based on the speed change. and throttle opening change The correction formula for the knock limit is: ； in, This is the correction factor for speed variation. This is the correction factor for throttle opening change. This is the initial detonation limit. This is the revised knock limit.

9. A method for diagnosing and controlling an automotive engine ignition system, characterized in that, Includes the following steps: S1: Extract the detonation characteristic frequency signal using a bandpass filtering algorithm; S2: Immediately execute the recoil angle when a detonation is detected based on the detonation characteristic frequency signal; S3: Corrects the knock limit based on changes in engine speed and throttle opening; S4: The sensor is identified by monitoring the standard deviation of the knock signal, and a sensor fault alarm is triggered based on the sensor abnormality. The standard deviation of the detonation signal in S4 is calculated as follows: ； when or When this occurs, a sensor fault alarm is triggered, in which... For the first Sub-detonation integral intensity The mean, The number of samples.

10. The method for diagnosing and controlling an automotive engine ignition system according to claim 9, characterized in that, It also includes dynamic calibration of knock limits, dividing the operating conditions into high, medium, and low ranges based on engine load, with knock limits for each range. The expression is: ； in, For high-load range limits, the recommended value is 90%-100% of the load when the throttle is fully open; The value used as the boundary between medium and low loads is taken as follows: The median of the initial detonation load.

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