Automobile engine supercharging control system and method

Abstract

The invention discloses an automobile engine supercharging control system and method, and particularly relates to the technical field of automobile engine supercharging control, and the system comprises a target supercharging pressure calculation module, a waste gas bypass valve control module, a deflation valve control module and a supercharging pressure diagnosis module. Control is achieved through the following steps that the performance limit of a gas compressor and the performance limit of an engine are synthesized, and the minimum value of the maximum supercharging values of the gas compressor and the engine serves as final target pressure; a closed-loop correction term is calculated based on a proportional integral (PI) algorithm, the duty ratio of a bypass valve is adjusted, and dynamic pressure tracking is achieved; the deflation valve is controlled to be opened and closed in real time according to the accelerator pedal change rate and the pressure threshold to prevent overhigh pressure; and the fault that the supercharging pressure is too high or too low is diagnosed by presetting an enabling condition and a pressure threshold value. Through multi-module cooperation, self-adaptive working condition adjustment and a multi-protection mechanism, the supercharging control precision, the system robustness and the engine safety are improved, and the method is suitable for real-time control scenes of various turbocharged engines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile engine supercharging control, and more particularly, to an automobile engine supercharging control system and method. BACKGROUND

[0002] In the field of automobile engine turbocharging technology, precise regulation of supercharging pressure is the core challenge to improve engine power performance, fuel economy and reliability. The existing supercharging control system generally has the following technical bottlenecks: Traditional schemes usually set the supercharging target based on a single operating parameter (such as engine speed), without fully integrating multi-dimensional constraints such as compressor characteristics, engine load and throttle restrictions. For example, when determining the target pressure according to the speed table alone, the compressor efficiency may decrease due to the increase in intake air temperature, or the intake back pressure may exceed the limit due to insufficient throttle opening, ultimately causing power output fluctuations or engine overload risk.

[0003] The existing closed-loop control mostly uses fixed parameter proportional adjustment, lacking integral correction and dynamic learning mechanism for pressure deviation. When the engine operating conditions change suddenly (such as sudden acceleration, gear shifting), the bypass valve control duty cycle cannot quickly match the pressure change demand, easily leading to supercharging lag or overshoot. For example, in high load conditions, pressure deviation accumulation may cause turbine delay, while in low load conditions, excessive supercharging may lead to deterioration of fuel economy.

[0004] For abnormal scenarios of excessively high or low supercharging pressure, the existing diagnosis mostly relies on a single threshold trigger, and lacks real-time dynamic correction logic. For example, when the atmospheric pressure changes or the intercooler efficiency decreases, the fixed threshold cannot be adjusted adaptively, which may cause the wastegate valve to malfunction or delay fault diagnosis, and in severe cases, cause mechanical damage to the engine (such as cylinder knock, turbine blade overload).

[0005] Hardware aging (such as bypass valve actuator wear) or changes in environmental parameters (such as altitude, temperature) will cause control parameter drift, but the existing system lacks self-learning ability and needs to be calibrated manually. For example, in high-altitude areas, the decrease in atmospheric pressure will directly affect the output efficiency of the compressor, and if the pressure reference is not dynamically corrected, the actual supercharging pressure will deviate from the target value, affecting the stability of engine power output.

[0006] Therefore, the present application provides an automobile engine supercharging control system and method. SUMMARY

[0007] In order to overcome the above-mentioned defects of the prior art, the present application provides an automobile engine supercharging control system and method to solve the problems raised in the background art.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical scheme: an automobile engine supercharging control system, comprising: a target boost pressure calculation module configured to calculate a target boost pressure according to engine operating parameters, including a compressor boost pressure maximum, an engine boost pressure maximum, and a final target boost pressure; a wastegate control module configured to adjust a wastegate duty cycle according to a target boost pressure and an actual boost pressure deviation; a bleed valve control module configured to control a bleed valve opening and closing according to an intake pressure change rate and a duration; a boost pressure diagnosis module configured to diagnose a boost pressure too high or too low abnormality.

[0009] Preferably, in the target boost pressure calculation module, the compressor boost pressure maximum is calculated by:

[0010] wherein, , is a compressor characteristic lookup table function, is an engine speed, is an intake mass flow rate, is an intake temperature, is an atmospheric pressure correction value, is an afterfilter pressure, is a pre-intercooler pressure loss.

[0011] Preferably, the engine boost pressure maximum is calculated by:

[0012] wherein, is an engine characteristic lookup table function, is an intercooler outlet temperature, is a throttle pressure ratio limit coefficient, is a load correction value, is a pre-intercooler pressure loss.

[0013] Preferably, the bleed valve enabling condition includes:

[0014] wherein, is an accelerator pedal position change amount, , is an acceleration / deceleration speed threshold value, is a bleed valve target pressure, , are pressure minimum and maximum threshold values.

[0015] Preferably, the boost pressure too high diagnosis enabling condition includes:

[0016] wherein, is a diagnostic threshold for rotational speed, is an intake manifold pressure, is an atmospheric pressure, is a pressure ratio threshold.

[0017] The control method of the turbocharged control system of an automobile engine according to the above description comprises the following steps: a target turbocharged pressure calculation step: obtaining a compressor turbocharged pressure maximum value and an engine turbocharged pressure maximum value , taking the minimum value of the two as the final turbocharged pressure maximum value ; a wastegate valve control step: calculating a closed-loop correction term according to the deviation between the target pressure and the actual pressure, and adjusting the wastegate valve control duty cycle based on the correction term; a bleed valve control step: judging the bleed valve opening condition according to the accelerator pedal position rate of change and the intake pressure threshold; a turbocharged pressure diagnosis step: diagnosing the turbocharged pressure abnormality through preset enabling conditions and pressure thresholds.

[0018] Preferably, the calculation formula of the wastegate valve preset pressure is:

[0019] wherein, , is a wastegate valve characteristic lookup table function, is a normalized engine load percentage, is an atmospheric pressure.

[0020] Preferably, the calculation of the wastegate valve control duty cycle comprises: an open-loop term: ; a closed-loop term: ; a final duty cycle: ; wherein, is a corrected wastegate valve preset pressure, , is a proportional integral coefficient, is an actual turbocharged pressure, is a duty cycle lookup table function, is a maximum duty cycle, is a learning correction factor.

[0021] Preferably, the turbocharged pressure too low diagnosis threshold is calculated as:

[0022] wherein, is the intake temperature correction coefficient, is the reference pressure threshold value, is the inertia correction value, is the safety margin.

[0023] Technical effects and advantages of the present application: 1. Through the cooperative work of the target supercharging pressure calculation module, the waste gas bypass valve control module, the air release valve control module and the supercharging pressure diagnosis module, the full-process precise control of the engine supercharging pressure is realized. The target pressure calculation comprehensively considers the performance limits of the compressor and the engine to avoid overpressure risks; the bypass valve adopts proportional integral closed-loop control combined with open-loop preset pressure to dynamically adjust the duty cycle to ensure that the supercharging pressure quickly and stably tracks the target value.

[0024] 2. By introducing the compressor and engine supercharging maximum value calculation into the lookup table function, combined with real-time parameters such as engine speed, intake flow and temperature, the supercharging demand under different working conditions is dynamically matched. For example, the switching logic of the throttle pressure ratio limit mode and the non-limit mode can automatically adjust the pressure upper limit according to the engine load to avoid throttle overload or power deficiency.

[0025] 3. By judging the opening condition through the acceleration pedal change rate and the pressure threshold value, the pressure is quickly released when the supercharging pressure abnormally rises to prevent engine overpressure damage.

[0026] 4. Through the preset enable condition and multi-layer threshold calculation of the supercharging pressure too high or too low diagnosis module, the pressure abnormality can be monitored in real time, triggering an alarm or protection action.

[0027] 5. The bypass valve duty cycle introduces a learning correction factor, which automatically optimizes the control parameters according to the actual pressure deviation through closed-loop correction terms and duty cycle learning area division, reducing control errors caused by hardware aging or environmental changes. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the control method flowchart of the automobile engine supercharging control system of the present application. DETAILED DESCRIPTION

[0029] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0030] The automobile engine supercharging control system provided by the present application comprises: a target supercharging pressure calculation module for calculating a target supercharging pressure according to engine operating parameters, including a compressor supercharging pressure maximum value, an engine supercharging pressure maximum value and a final target supercharging pressure; A wastegate valve control module, configured to adjust a wastegate valve duty cycle based on a deviation between a target boost pressure and an actual boost pressure; The purge valve control module is used to control the opening and closing of the purge valve according to the intake pressure change rate and duration; The boost pressure diagnostic module is used to diagnose abnormalities of excessively high or low boost pressure.

[0031] During specific implementation, the target boost pressure calculation module calculates the appropriate target boost pressure based on the engine operating parameters, such as speed, intake air flow, temperature, etc., to provide a reference value for subsequent control. The exhaust bypass valve control module adjusts the duty cycle of the bypass valve according to the deviation between the target boost pressure and the actual pressure, thereby controlling the flow of exhaust gas and then adjusting the boost pressure. The bleed valve control module controls the opening and closing of the bleed valve according to the changes in the intake pressure to prevent excessive boost pressure from damaging the engine. The boost pressure diagnosis module monitors the boost pressure in real time and diagnoses when it is too high or too low to ensure safe and stable operation of the system, thereby realizing precise control and real-time monitoring of the engine boost pressure, and being able to adjust the boost pressure according to different operating conditions of the engine to improve the engine's power performance and fuel economy, while enhancing the reliability and safety of the system.

[0032] In the target boost pressure calculation module, the maximum value of the compressor boost pressure is calculated as follows:

[0033] in, 、 is the compressor characteristic lookup function, is the engine speed, is the intake air mass flow rate, is the intake air temperature, is the atmospheric pressure correction value, is the pressure after air filter, is the pressure loss before the intercooler.

[0034] In specific implementation, the compressor characteristic lookup table function is used and , combined with engine speed , intake air mass flow and intake air temperature , and obtain the pressure value related to the compressor performance. At the same time, consider the atmospheric pressure correction value , air filter pressure and pressure loss before intercooler , and finally calculate the maximum value of the compressor boost pressure Therefore, the maximum supercharging pressure that the compressor can provide can be calculated more accurately, which provides an accurate reference for subsequent determination of the final target supercharging pressure, and helps to improve the precision and efficiency of the supercharging control system.

[0035] The calculation method of the maximum engine supercharging pressure is as follows:

[0036] wherein, is an engine characteristic lookup table function, is the intercooler outlet temperature, is the throttle pressure ratio limit coefficient, is the load correction value, is the pressure loss before the intercooler.

[0037] In specific implementation, when the throttle pressure ratio limit is used, the engine characteristic lookup table function is calculated in combination with the intercooler outlet temperature , the throttle pressure ratio limit coefficient , the load correction value and the pressure loss after the intercooler . Otherwise, another way is used for calculation, which comprehensively considers the actual operation of the engine and the restriction of the throttle, can more accurately calculate the maximum supercharging pressure that the engine can withstand, avoids damage to the engine caused by excessively high supercharging pressure, and improves the safety and reliability of the engine.

[0038] The bleeder valve enabling condition includes:

[0039] wherein, is the accelerator pedal position change amount, , is the acceleration / deceleration threshold value, is the bleeder valve target pressure, , is the pressure minimum and maximum threshold value.

[0040] In specific implementation, the bleeder valve enabling condition is determined by comparing the accelerator pedal position change amount and the bleeder valve target pressure with the corresponding threshold value. When a specific condition is met, the bleeder valve is enabled to open to prevent excessively high supercharging pressure; when the condition is not met, the bleeder valve is prohibited from opening, so that the opening condition of the bleeder valve can be determined in real time according to the actual operation of the engine, effectively preventing damage to the engine caused by excessively high supercharging pressure, and improving the safety and reliability of the engine.

[0041] The excessively high supercharging pressure diagnosis enabling condition includes:

[0042] wherein, is a diagnostic rotation speed threshold value, is an intake manifold pressure, is an atmospheric pressure, is a pressure ratio threshold value.

[0043] In specific implementation, the supercharging pressure overhigh diagnosis enabling condition is determined according to the engine rotation speed and the ratio of the intake manifold pressure to the atmospheric pressure . When the engine rotation speed reaches a certain threshold value and the ratio of the intake manifold pressure to the atmospheric pressure exceeds a certain threshold value, the supercharging pressure overhigh diagnosis is enabled, so that the abnormal condition of supercharging pressure overhigh can be found in time, providing a basis for the system to take corresponding protection measures, avoiding damage to the engine caused by supercharging pressure overhigh, and improving the reliability and safety of the system.

[0044] As Figure 1 shown, the control method of the automobile engine supercharging control system provided by the application comprises the following steps: a target supercharging pressure calculation step: obtaining a supercharger supercharging pressure maximum value and an engine supercharging pressure maximum value , taking the minimum value of the two as the final supercharging pressure maximum value ; an exhaust gas bypass valve control step: calculating a closed-loop correction term according to the deviation of the target pressure and the actual pressure, and adjusting the bypass valve control duty cycle based on the correction term; a bleed valve control step: judging the bleed valve opening condition according to the acceleration pedal position change rate and the intake pressure threshold value; a supercharging pressure diagnosis step: diagnosing the supercharging pressure abnormality through the preset enabling condition and the pressure threshold value.

[0045] In specific implementation, first, the target supercharging pressure calculation step is used to comprehensively consider the supercharging pressure maximum values of the supercharger and the engine to determine the final target supercharging pressure. Then in the exhaust gas bypass valve control step, the closed-loop correction term is calculated according to the deviation of the target pressure and the actual pressure, and the control duty cycle of the bypass valve is adjusted to realize accurate control of the supercharging pressure. The bleed valve control step judges the bleed valve opening condition according to the acceleration pedal position change rate and the intake pressure threshold value to prevent the supercharging pressure from being too high. The supercharging pressure diagnosis step diagnoses the supercharging pressure abnormality through the preset enabling condition and the pressure threshold value, providing a clear and orderly supercharging control process, which can dynamically adjust the supercharging pressure according to the actual operation of the engine, improve the performance and reliability of the engine, and at the same time avoid damage to the engine caused by supercharging pressure abnormality.

[0046] The calculation formula of the exhaust bypass valve preset pressure is:

[0047] wherein, , is a bypass valve characteristic lookup table function, is a normalized engine load percentage, is an atmospheric pressure.

[0048] In specific implementation, the calculation of the exhaust bypass valve preset pressure is obtained by the bypass valve characteristic lookup table function and , in combination with the engine speed , the normalized engine load percentage , the intake mass flow , and the atmospheric pressure , and minus the pre-intercooler pressure loss , which can provide a preset pressure value for the control of the exhaust bypass valve, so that the bypass valve can be adjusted according to the deviation between the preset value and the actual pressure, thereby more effectively controlling the boost pressure and improving the performance of the engine.

[0049] The calculation of the bypass valve control duty cycle includes: an open-loop term: ; a closed-loop term: ; a final duty cycle: ; wherein, is a corrected bypass valve preset pressure, , are proportional integral coefficients, is an actual boost pressure, is a duty cycle lookup table function, is a maximum duty cycle, is a learning correction factor.

[0050] In specific implementation, the calculation of the bypass valve control duty cycle is divided into an open-loop term and a closed-loop term. The open-loop term is calculated according to the difference between the target boost pressure and the corrected bypass valve preset pressure, which provides a basic control amount. The closed-loop term adopts a proportional integral control algorithm and is calculated according to the deviation between the actual boost pressure and the target boost pressure, so as to eliminate the error of the system. The final duty cycle is adjusted by the lookup table function and the learning correction factor , and by adopting the control mode of combining the open-loop and the closed-loop, the duty cycle of the bypass valve can be more accurately adjusted, so that the boost pressure can quickly and stably reach the target value, thereby improving the response speed and control accuracy of the boost control system.

[0051] The boost pressure too low diagnosis threshold is calculated as:

[0052] Wherein, is an intake temperature correction coefficient, is a reference pressure threshold, is an inertia correction value, is a safety margin.

[0053] In the specific implementation, the calculation of the boost pressure too low diagnosis threshold comprehensively considers the maximum value of the final target boost pressure , the intake temperature correction coefficient , the reference pressure threshold , the inertia correction value and the safety margin , accurately determines the diagnosis threshold of the boost pressure too low, can timely find the abnormal condition of the boost pressure too low, provides a basis for the system to take corresponding measures, and ensures the normal operation of the engine.

[0054] The above merely describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for diagnosing interference and jamming of an automobile engine pressure sensor, characterized in that: The following steps are involved: Obtain the output signal of the automobile engine pressure sensor in real time; Based on a preset normal signal range, determining whether the output signal is within a normal range; If the output signal exceeds the normal range, further analyze the signal characteristics to determine whether it is an interference or stuck fault; Take appropriate measures based on the fault type.

2. The method for diagnosing interference and jamming of an automobile engine pressure sensor according to claim 1, characterized in that: The real-time acquisition of the output signal of the automobile engine pressure sensor includes acquiring the output signal of at least one pressure sensor among an intake pressure sensor, an exhaust pressure sensor, and a fuel pressure sensor.

3. The method for diagnosing interference and jamming of an automobile engine pressure sensor according to claim 1, characterized in that: The preset normal signal range is calculated based on a large amount of experimental data and engine models according to different engine operating conditions.

4. The method for diagnosing interference and jamming of an automobile engine pressure sensor according to claim 1, characterized in that: The further analysis of the signal characteristics to determine whether it is an interference or stuck fault specifically includes: If the output signal fluctuates at high frequencies and the amplitude exceeds the normal range, but the duration is short, it is determined to be an interference fault; If the output signal remains at a fixed value for a long time or fluctuates within a very small range and does not match the current engine operating conditions, it is determined to be a stuck fault.

5. The method for diagnosing interference and jamming of an automobile engine pressure sensor according to claim 1, characterized in that: The corresponding handling measures are taken according to the fault type, including: For interference faults, the signal filtering program is started to filter the sensor output signal to eliminate the interference signal; For stuck faults, an alarm signal is issued to alert the driver and the fault code is recorded. At the same time, an attempt can be made to restore the normal operation of the sensor by adjusting the engine control parameters.

6. A system for executing the method for diagnosing interference and jamming of an automobile engine pressure sensor according to any one of claims 1 to 5, characterized in that: include: Signal acquisition module, used to obtain the output signal of the automobile engine pressure sensor in real time; A signal determination module, which determines whether the output signal is within a normal range based on a preset normal signal range; Fault analysis module: if the output signal exceeds the normal range, further analyze the signal characteristics to determine whether it is an interference or stuck fault; The processing execution module takes corresponding processing measures according to the fault type.

7. The automobile engine pressure sensor interference and jamming diagnosis system according to claim 6, characterized in that: The signal acquisition module includes a signal acquisition circuit connected to the intake pressure sensor, the exhaust pressure sensor, and the fuel pressure sensor, and is used to accurately acquire the output signals of each pressure sensor.

8. The automobile engine pressure sensor interference and jamming diagnosis system according to claim 6, characterized in that: The signal judgment module stores a normal signal range database determined according to different engine operating conditions, and makes judgments by comparing the sensor output signal with the corresponding value in the database.

9. The automobile engine pressure sensor interference and jamming diagnosis system according to claim 6, characterized in that: The fault analysis module includes a signal characteristic analysis unit for performing high-frequency fluctuation analysis and duration analysis on output signals exceeding a normal range to distinguish interference faults from stuck faults.

10. The automobile engine pressure sensor interference and jamming diagnosis system according to claim 6, characterized in that: The processing execution module includes a signal filtering submodule, an alarm issuing submodule, a fault code recording submodule and a parameter adjustment submodule, which are respectively used to process interference faults, issue alarms, record fault codes and try to restore normal operation of the sensor.

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