Method and system for post-processing of electronic wastegate valve failure in a turbocharged engine

Abstract

The application discloses a kind of waste gas turbocharged engine electronic pressure relief valve failure post-processing method, it includes the following steps: when detecting that electronic pressure relief valve cannot open, the following control is carried out: the optimization control of throttle effective area change rate;Lower target boost pressure;Lower engine minimum ignition angle efficiency;When detecting that electronic pressure relief valve cannot close, the following control is carried out: improve target boost pressure;Close throttle effective area self-learning;Prohibit carbon tank control activation.The application also provides a kind of waste gas turbocharged engine electronic pressure relief valve failure post-processing system.The application can carry out post-processing to waste gas turbocharged engine electronic pressure relief valve failure, can avoid engine surge, improve engine judder, even the problem of engine flameout.

Description

Technical Field

[0001] This invention belongs to the field of engine control, specifically relating to a method and system for handling the failure of the electronic pressure relief valve in an exhaust gas turbocharged engine. Background Technology

[0002] When a turbocharged engine releases the accelerator or shuts down, causing torque to decrease, the throttle valve closes rapidly to reduce intake air volume and achieve the torque reduction effect. This rapid throttle closure opens the wastegate, allowing air to flow through it. If the wastegate fails to open properly (meaning it remains closed and cannot be opened), the engine may experience turbocharger surge when power is requested (airflow oscillates between the throttle valve and the compressor), potentially causing engine vibration. Conversely, when the driver presses the accelerator or the engine requests boost, the wastegate must close to prevent airflow and ensure a rapid response to boost demands and power output. If the wastegate fails to close properly, the engine may struggle to respond to increased power demands with sufficient torque, potentially even stalling.

[0003] Patent publication number CN109779742A, entitled "A Failure Monitoring System and Method for an Engine Intake Electronic Pressure Relief Valve," discloses a method for monitoring the failure of a pressure relief valve. However, this method does not address post-failure handling measures. If monitoring only reports a fault code to alert the driver when the pressure relief valve fails, the engine may still malfunction, vibrate, or even stall. Therefore, it is necessary to research post-failure handling measures for electronic pressure relief valves to minimize engine performance degradation, vibration, and stalling. Summary of the Invention

[0004] The main objective of this invention is to provide a method and system for handling the failure of the electronic pressure relief valve in a turbocharged exhaust gas engine. This method and system can prevent engine surge, improve engine vibration, and even prevent engine stalling.

[0005] The technical solution adopted in this invention is:

[0006] A method for handling the failure of the electronic pressure relief valve in an exhaust gas turbocharged engine, comprising the following steps:

[0007] When the electronic pressure relief valve is detected to be unable to open, the following control measures are implemented:

[0008] Optimized control of the effective throttle area change rate;

[0009] Reduce target boost pressure;

[0010] Reduce engine minimum ignition angle efficiency;

[0011] When the electronic pressure relief valve is detected to be unable to close, the following control measures are implemented:

[0012] Increase the target boost pressure;

[0013] Self-learning of effective throttle valve area;

[0014] Carbon canister control activation is prohibited.

[0015] The present invention also provides a post-failure treatment system for the electronic wastegate of an exhaust gas turbocharged engine. The system adopts the above-mentioned post-failure treatment method for the electronic wastegate of an exhaust gas turbocharged engine and includes an engine controller (EMS), a boost pressure sensor, an atmospheric pressure sensor, an intake pressure sensor, a turbocharger, and an electronic wastegate body.

[0016] The boost pressure sensor and atmospheric pressure sensor are located after the engine intake compressor. The boost pressure sensor reads the gas pressure at the compressor outlet, and the atmospheric pressure sensor reads the gas pressure in the atmosphere. The intake pressure sensor, turbocharger, and electronic pressure relief valve body are located after the throttle valve. The intake pressure sensor reads the gas pressure after the throttle valve, the turbocharger achieves the intake pressure, and the boost pressure relief valve body allows airflow to flow from the relief valve to the front of the compressor when the intake pressure decreases, preventing airflow from oscillating back and forth within the compressor and causing surge. The boost pressure sensor, atmospheric pressure sensor, and intake pressure sensor transmit the collected data to the engine control system (EMS). The EMS controls the turbocharger intake and the opening and closing of the electronic pressure relief valve, performing optimized control of the throttle effective area change rate, control to reduce the target boost pressure, control to reduce the engine minimum ignition angle efficiency, or control to increase the target boost pressure, disable throttle effective area self-learning control, and disable canister control activation control. It also monitors for pressure relief valve failure and reports a fault code to alert the driver.

[0017] The beneficial effects of this invention are:

[0018] When the electronic pressure relief valve fails to open or close, the after-treatment control method is optimized to avoid engine surge and improve engine vibration or even stalling.

[0019] When the electronic pressure relief valve fails to open, appropriately reduce the target boost pressure to avoid booster surge when the boost pressure drops suddenly;

[0020] When the electronic pressure relief valve fails to open, the minimum ignition angle efficiency is reduced to ensure the accuracy of the engine's firing torque even if the gas path torque decreases too slowly.

[0021] When the electronic pressure relief valve fails to close, the target boost pressure should be appropriately increased to compensate for insufficient torque capacity caused by boost pressure leakage when power demand increases. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating the handling method after the failure of the electronic pressure relief valve in a turbocharged exhaust gas engine.

[0024] Figure 2 This is a structural block diagram of the after-treatment system for the failure of the electronic pressure relief valve in a turbocharged exhaust engine.

[0025] Figure 3 This is a flowchart illustrating the optimized control process for reducing the rate of change of the effective throttle valve area. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] Example 1

[0028] See Figure 2 A post-failure treatment system for the electronic wastegate of an exhaust gas turbocharged engine is disclosed. The system adopts the above-mentioned post-failure treatment method for the electronic wastegate of an exhaust gas turbocharged engine and includes an engine controller (EMS), a boost pressure sensor, an atmospheric pressure sensor, an intake pressure sensor, a turbocharger, and an electronic wastegate body.

[0029] The boost pressure sensor and atmospheric pressure sensor are located after the engine intake compressor. The boost pressure sensor reads the gas pressure at the compressor outlet, and the atmospheric pressure sensor reads the gas pressure in the atmosphere. The intake pressure sensor, turbocharger, and electronic pressure relief valve are located after the throttle valve. The intake pressure sensor reads the gas pressure after the throttle valve, the turbocharger achieves the intake pressure, and the pressure relief valve allows airflow to pass through the relief valve to the front of the compressor when the intake pressure decreases, preventing airflow from oscillating back and forth within the compressor and causing surge. The boost pressure sensor, atmospheric pressure sensor, and intake pressure sensor transmit the collected data to the engine control system (EMS). The EMS controls the turbocharger intake and the opening and closing of the electronic pressure relief valve, performing optimized control of the throttle effective area change rate, control to reduce the target boost pressure, control to reduce the engine minimum ignition angle efficiency, or control to increase the target boost pressure, disable throttle effective area self-learning control, and disable canister control activation control. It also monitors for pressure relief valve failure and reports a fault code to alert the driver. The opening / closing control of the electronic pressure relief valve can be implemented according to the patent number: 202010109543.2, patent name: control method of pressure relief valve for turbocharged engine.

[0030] Example 2

[0031] If monitoring a pressure relief valve malfunctions, merely reporting a fault code to alert the driver may result in the engine failing to operate normally, vibrating, or even stalling. This invention addresses a post-processing method for malfunctions where the intake electronic pressure relief valve cannot open or close. A pressure relief valve failing to open means it remains closed, and attempts to open it fail. Patent No. 201910218153.6, entitled "A Failure Monitoring System and Method for an Engine Intake Electronic Pressure Relief Valve," discloses a failure detection method for whether the electronic pressure relief valve cannot open. Patent No. 202210676075.6, entitled "A Method for Monitoring the Performance of an Engine Intake Electronic Pressure Relief Valve," discloses a detection method for whether the electronic pressure relief valve cannot close. This invention provides a post-processing control method for these two malfunction scenarios.

[0032] See Figure 1 In the first scenario, if the electronic wastegate fails to open, the engine may experience turbocharger surging when requesting power output, potentially even causing engine vibration. When this electronic wastegate malfunction occurs, the following after-processing controls should be implemented:

[0033] See Figure 31. Optimization of throttle opening control (optimized control to reduce the rate of change of effective throttle area), namely, patent number: 202010109520.1, patent name: update of the rate of change of effective throttle area in the control system and method of electronic throttle for exhaust gas turbocharged engine.

[0034] The activation condition for optimizing the effective throttle area change rate is:

[0035] 1. Patent No. CN202010109543.2, Patent Title: Control Method for Pressure Relief Valve of Turbocharged Engine, proposes that the pressure relief valve opens when the actual pressure ratio between the front and rear of the turbocharger reaches or exceeds the first pressure ratio setting value.

[0036] 2. The engine did not experience strong knocking; strong knocking is defined as an engine knocking that retards the ignition angle by more than 0.8 times the maximum retardation angle. In this example, the maximum retardation angle is taken as 10°.

[0037] 3. Exhaust temperature has not reached its maximum. To protect the engine exhaust system, the maximum exhaust temperature is limited. In this example, the maximum exhaust temperature of the engine is 950°C.

[0038] Only after all the above conditions are met can the effective throttle area be optimized. The optimization goal is to prevent turbocharger surge after the pressure relief valve fails to open. Based on this goal, the following parameters are determined through research and experimentation to determine the optimization coefficient r of the effective throttle area change rate. Thr (optimization coefficient r) Thr (Values ​​not greater than 1):

[0039] 1) When the boost control is in closed-loop control; (Whether the boost control closed loop is activated or not can be seen in patent number: 201910988050.8, patent name: Boost Closed-Loop Adaptive System and Control Method for Exhaust Gas Turbine Engine)

[0040] r Thr =f(n.rho)×f(p) PreThr ,dp PreThr )×f1(p AftThr ,dp AftThr )×(1+r Adapt )

[0041] 2) When the boost control is in a non-closed-loop control state;

[0042] r Thr =f(n.rho)×f(p) PreThr ,dp PreThr )×f2(p AftThr ,dp AftThr )×(1+r Adapt )

[0043] f(n.rho) is a fundamental factor determined based on engine speed n and fresh air intake density rho entering the cylinder, f(p PreThr ,dp PreThr (This is based on the gas pressure p before the throttle valve) PreThr and the rate of change of gas pressure before throttle valve dp PreThr The determined correction factor, f1(p) AftThr ,dp AftThr f2(p) and f2(p) AftThr ,dp AftThr All are based on the gas pressure p after the throttle valve. AftThr and the rate of change of gas pressure after throttle valve dp AftThr A defined correction factor, r Adapt This is the self-learning correction coefficient, which defaults to 0 and can be continuously updated through self-learning. Where f1(p) AftThr ,dp AftThr ) is not greater than f2(p AftThr ,dp AftThr In the boost control closed loop, because the boost actuator responds quickly and has a poorer pressure relief capacity, it is even more necessary to reduce the rate of change of the effective throttle area during boost control closed loop. f(n.rho)×f(p) PreThr ,dp PreThr )×f2(p AftThr ,dp AftThr The calibration data were all obtained through experimental testing. The calibration was based on the fact that no turbocharger surge occurred after the pressure relief valve failed to open.

[0044] First, the baseline factor f(n.rho) is calibrated. Then, under closed-loop turbocharging conditions, engine bench tests are conducted at different engine speeds n and different fresh air intake densities rho entering the cylinders. The gas pressure p before the throttle valve is initially fixed. PreThr The rate of change of gas pressure before the throttle valve is dp, which is 101 kPa. PreThr The gas pressure p after the throttle valve is -10 kPa / s. AftThr The rate of change of gas pressure after the throttle valve is dp, which is 70 kPa. AftThr The calibration was obtained at -6 kPa / s, and the calibration data is as follows:

[0045]

[0046] Then, after calibrating the base factor f(n.rho), the correction factor f(p) is calibrated. PreThr ,dp PreThrThe method for determining this is to conduct engine bench tests under closed-loop turbocharging conditions, with a fixed engine speed n and a fresh air intake density rho entering the cylinder, while simultaneously fixing the gas pressure p after the throttle valve. AftThr The rate of change of gas pressure after the throttle valve is dp, which is 70 kPa. AftThr The value is -6 kPa / s, obtained by calibrating the inlet gas pressure and the rate of change of inlet gas pressure. The calibration data is as follows:

[0047]

[0048] Then calibrate the correction factor f1(p) AftThr ,dp AftThr f2(p) and f2(p) AftThr ,dp AftThr The method for determining this is to conduct engine bench tests at a fixed engine speed n and a fresh air intake density rho entering the cylinder, while simultaneously fixing the gas pressure p before the throttle valve. PreThr The rate of change of gas pressure before the throttle valve is dp, which is 101 kPa. PreThr The value is -10 kPa / s, calibrated by varying the gas pressure after the throttle valve and the rate of change of the gas pressure after the throttle valve. f1(p AftThr ,dp AftThr f2(p) is obtained by calibration under closed-loop pressure conditions. AftThr ,dp AftThr The calibration data was obtained under non-closed-loop conditions during boost, and the calibration data is as follows:

[0049] f1(p AftThr ,dp AftThr The calibration is as follows:

[0050]

[0051] f2(p AftThr ,dp AftThr The calibration is as follows:

[0052]

[0053] Self-learning correction coefficient r Adapt The default value is 0, and it can continuously learn and update itself, and can be saved after the vehicle is powered off. Its learning conditions are as follows:

[0054] 1. The pressure relief valve opening condition proposed in patent CN202010109543.2, "Control Method of Pressure Relief Valve for Turbocharged Engine", is met, namely: when the actual pressure ratio before and after the turbocharger reaches or exceeds the first pressure ratio setting value, the pressure relief valve opens.

[0055] 2. The engine did not experience strong knocking; strong knocking is defined as an engine knocking that retards the ignition angle by more than 0.8 times the maximum retardation angle. In this example, the maximum retardation angle is taken as 10°.

[0056] 3. Exhaust temperature has not reached its maximum. To protect the engine exhaust system, the maximum exhaust temperature is limited. In this example, the maximum exhaust temperature of the engine is 950°C.

[0057] 4. The ratio of gas pressure after the throttle to gas pressure before the throttle. Not exceeding the preset value. The preset value in this example is related to the engine speed n. (Regarding pressure ratio...) When the pressure ratio is too high, the intake pressure will fluctuate due to the poor throttling effect of the throttle valve, which may interfere with the accuracy of the self-learning correction coefficient. To avoid this situation, it is necessary to limit the pressure ratio to too high.

[0058] The relationship between the preset value and the engine speed n is as follows:

[0059]

[0060] After all the above conditions are met, the intake pressure fluctuation characteristic signal within the accumulated time T1 (2 seconds in this example) is updated with a self-learning correction coefficient:

[0061] The intake pressure of the actual gas entering the cylinder is processed by a first-order low-pass filter:

[0062] p ActManFilter (N)=K ManPre ×[p ActMan (N)-p ActManFilter [(N-1)]+p ActManFilter (N-1)

[0063] Where, p ActMan p represents the actual intake pressure of the gas entering the cylinder. ActMan (N) represents the actual intake pressure of the gas entering the cylinder during the Nth sampling period, p ActManFilter p represents the actual intake pressure of the gas entering the cylinder after a first-order low-pass filter. ActManFilter (N) represents the filtered intake pressure of the actual gas entering the cylinder during the Nth sampling period, p ActManFilter (N-1) represents the filtered intake pressure of the actual gas entering the cylinder during the (N-1)th sampling period, where N = 1, 2, 3, ..., p ActManFilter (0) equals the actual intake pressure p of the gas entering the cylinder during the 0th sampling period. ActMan (0), the start time of the 0th sampling period refers to the moment when the electronic pressure relief valve fails to open; the sampling period interval Δt is 10ms in this example. K ManPre For coefficients: (In this example, the engine has 4 cylinders m and k) ManPre The calibration speed is 1000 rpm. The purpose of this setting is for normalization processing. No special calibration is needed for different numbers of cylinders and engine speeds; only the 4-cylinder engine and the k-type engine at 1000 rpm need to be calibrated. ManPre (This reduces calibration testing work), where m is the number of engine cylinders, n is the engine speed, and k ManPre k is the throttle outlet intake pressure filtering coefficient. ManPre The filter coefficient is 0.12 in this example.

[0064] if,

[0065] 1) If r is greater than the preset value A1 (4000 in this example), then Adapt =r Adapt (z)-0.01;

[0066] 2) If r is not greater than the preset value A1, but greater than A2 (A2 is not greater than A1, and is taken as 2000 in this example), then r Adapt =r Adapt (z)-0.0065;

[0067] 3) If r is not greater than the preset value A2, but greater than A3 (1000 in this example), then r Adapt =r Adapt (z)-0.002;

[0068] 4) If r is not greater than the preset value A3, but greater than A4 (500 in this example), then r Adapt =r Adapt (z);

[0069] 5) If r is not greater than the preset value A4, but greater than A5 (300 in this example), then r Adapt =r Adapt (z)+0.002;

[0070] Where, r Adapt (z) is the correction coefficient from the previous self-learning update; r Adapt This is the self-learning correction coefficient, which has a default value of 0 and can be continuously updated through self-learning.

[0071] The self-learning correction coefficient is updated at most once during each driving cycle.

[0072] Optimization coefficient r of throttle effective area change rate ThrOnce the calculation is complete, compare it with the preset value 1 (it is 1 without optimization, and a number no greater than 1 after optimization) and select the minimum value.

[0073] The optimized throttle effective area change rate dA is obtained by minimizing the value. Thr The optimized throttle effective area change rate dA Thr The rate of change of effective throttle area when the optimization condition for effective throttle area is met:

[0074] dA Thr =dA ThrRaw ×r Thr , where dA ThrRaw The effective throttle area change rate before optimization (see patent number: 202210755703.X, patent name: an electronic throttle control method for a turbocharged direct injection gasoline engine) is used in the control of the throttle.

[0075] Second, optimize the target boost pressure, that is, appropriately reduce the target boost pressure to avoid turbocharger surge when the boost pressure suddenly drops. The optimized target boost pressure correction coefficient r... BoostPre This depends on both the target boost pressure ratio before optimization and the engine speed. The target boost pressure ratio before optimization refers to the ratio of the target boost pressure before optimization to the actual pressure at the turbocharger compressor inlet. The calibration in this example is as follows:

[0076]

[0077] The optimized target boost pressure correction factor r BoostPre Multiplying the target boost pressure before optimization yields the optimized target boost pressure. Finally, the optimized target boost pressure is used for boost control. The target boost pressure before optimization can be obtained from the patent (patent number: 202010109549.X, patent title: Method for determining target boost pressure of exhaust gas turbocharged engine, storage medium).

[0078] 3. Reduce engine minimum ignition angle efficiency. Reducing the minimum ignition angle efficiency ensures the accuracy of the engine's firing torque even when the gas path torque decreases too slowly (in this example, the difference between the requested firing torque and the actual firing torque must not exceed ±5 Nm). The triggering conditions for reducing the engine's minimum ignition angle efficiency are as follows:

[0079] 1. The pressure relief valve opening condition proposed in patent CN202010109543.2, "Control Method of Pressure Relief Valve for Turbocharged Engine", is met, namely: when the actual pressure ratio before and after the turbocharger reaches or exceeds the first pressure ratio setting value, the pressure relief valve opens.

[0080] 2. The engine did not experience strong knocking; strong knocking is defined as an engine knocking that retards the ignition angle by more than 0.8 times the maximum retardation angle. In this example, the maximum retardation angle is taken as 10°.

[0081] 3. Exhaust temperature has not reached its maximum. To protect the engine exhaust system, the maximum exhaust temperature is limited. In this example, the maximum exhaust temperature of the engine is 950°C.

[0082] 4. Reduce the engine's minimum ignition angle efficiency so that continuous triggering does not exceed the preset time T1 (2 seconds in this example). Prolonged reduction in the engine's minimum ignition efficiency can lead to poor combustion stability and engine vibration.

[0083] Once the above conditions are met, optimization to reduce the ignition angle efficiency will be performed.

[0084] When the boost is not in closed-loop mode, the minimum ignition efficiency correction factor is r. MinSprk =r MinSprk1 ;

[0085] r MinSprk1 The calibration is as follows:

[0086]

[0087] When the boost is in closed-loop mode, the minimum ignition efficiency correction factor is r. MinSprk =r MinSprk2 .

[0088] r MinSprk2 The calibration is as follows:

[0089]

[0090] r MinSprk2 Not greater than r MinSprk1 This means that when the turbocharger is in a closed-loop state, the engine's airflow torque is relatively large, requiring a reduction in ignition angle efficiency to achieve the desired accuracy in the firing torque. Based on this, r is calibrated. MinSprk2 and r MinSprk1 .

[0091] When switching from pressurized closed-loop to non-closed-loop mode, or from non-closed-loop to closed-loop mode, the minimum ignition efficiency correction factor r MinSprk The rate of change does not exceed ±0.015 / 10ms.

[0092] r MinSprkRatioFinal =r MinSprk ×r MinSprkRatioRaw

[0093] Where r MinSprkRatioRawThe minimum ignition angle efficiency before optimization (see patent CN202210676269.6 "A method for controlling the minimum ignition efficiency of a gasoline engine"), r MinSprkRatioFinal The optimized minimum ignition angle efficiency is used in the control of the minimum ignition angle efficiency. For details on the minimum ignition angle efficiency control method, please refer to CN202210676269.6 "A method for controlling the minimum ignition efficiency of a gasoline engine".

[0094] See Figure 1 In the second scenario, if the electronic wastegate fails to close, the engine will exhibit a problem where it cannot respond promptly to increased power demands, particularly in terms of torque output. When this electronic wastegate malfunction occurs, the following after-processing controls are implemented:

[0095] 1. Increase the target boost pressure. That is, appropriately increase the target boost pressure to improve the insufficient torque capacity caused by boost pressure leakage when power demand increases.

[0096] First, estimate the gas pressure p at the inlet of the pressure relief pipe, where it intersects with the intake pipe. BoostJuction :

[0097]

[0098] Where, p PreThr The boost gas pressure before the throttle valve. For the fresh air flow rate entering the cylinder, A Junction T is the area of ​​the pressure relief pipe inlet at the junction of the pressure relief pipe inlet and the intake pipe. PreThr R is the temperature of the boosted gas before the throttle valve, and R is the ideal gas constant.

[0099] The optimized target boost pressure p BoostDsrd :

[0100]

[0101] Where, p BoostDsrdRaw The known target boost pressure before optimization, n is the engine speed, and M is... SparkDsrd For the requested fire torque, M SparkAct For the actual fire circuit torque, r BoostAdapt This is the self-learning correction coefficient for boost pressure. Where the self-learning correction coefficient r... BoostAdapt The default value is 0, which allows for continuous self-learning and updates throughout the vehicle's lifecycle and can be saved after the vehicle is powered off.

[0102] In the self-learning correction coefficient r BoostAdapt The value is calibrated to 0, and it is determined by the difference between engine speed n and the arc torque coefficient. The decision was made jointly, as shown in the table below:

[0103]

[0104] r BoostAdapt The boost pressure self-learning correction coefficient needs to be learned and updated under certain conditions, namely:

[0105] The boost control is in a closed-loop state;

[0106] The difference between the optimized target boost pressure and the actual boost pressure shall not exceed the preset value, which is 8 Nm in this example;

[0107] The throttle is fully open;

[0108] The engine speed fluctuation should not exceed the preset value, which is ±50 rpm in this example;

[0109] The optimized target boost pressure fluctuation should not exceed the preset value, which is ±2kPa in this example;

[0110] After the above conditions are met, the actual boost pressure is subjected to a first-order low-pass filter:

[0111] p ActBoostFilter (N)=K Boost ×[p ActBoost (N)-p ActBoostFilter [(N-1)]+p ActBoostFilter (N-1)

[0112] Where, p ActBoost p represents the actual boost pressure. ActBoost (N) represents the actual boost pressure in the Nth sampling period, p ActBoostFilter p represents the actual boost pressure after first-order low-pass filtering. ActBoostFilter (N) represents the filtered actual boost pressure during the Nth sampling period, p ActBoostFilter (N-1) represents the filtered actual boost pressure during the (N-1)th sampling period, where N = 1, 2, 3, ..., p ActBoostFilter (0) equals the actual boost pressure p during the 0th sampling period. ActBoost (0), the start time of the 0th sampling period refers to the moment when the electronic pressure relief valve fails to close; the sampling period interval Δt is 10ms in this example. K Boost For coefficients: (In this example, the engine has 4 cylinders m and k) Boost The calibration speed is 1000 rpm. The purpose of this setting is for normalization processing. No special calibration is needed for different numbers of cylinders and engine speeds; only the 4-cylinder engine and the k-type engine at 1000 rpm need to be calibrated. Boost(This reduces calibration testing work), where m is the number of engine cylinders, n is the engine speed, and k Boost This represents the actual boost pressure filtering coefficient. In this example, k... Boost The filter coefficient is 0.1.

[0113] Read the current average engine speed, the average target boost pressure before optimization, and the fluctuation characteristic signal. The average value r BoostEva The engine speed and the target boost pressure before optimization will fluctuate and are not fixed values. The operating conditions are determined by calculating the average value.

[0114] If r BoostEva If the value is ≥0.2, then update r under the same operating conditions (same average engine speed, same target boost pressure before optimization). BoostAdapt r BoostAdapt =k1×r BoostEva +r BoostAdapt (z), the learning weight coefficient k1 is 0.1, r BoostAdapt (z) is the self-learning correction coefficient of the boost pressure updated in the last learning cycle, which is updated at most once per driving cycle.

[0115] If 0.2 > r BoostEva If the value is ≥0.1, then update r under the same operating conditions (same average engine speed, same target boost pressure before optimization). Boos tAd ap t,

[0116] r BoostAdapt =k2×r BoostEva +r BoostAdapt (z), the learning weight coefficient k2 is 0.05.

[0117] If 0.02 <r BoostEva If the value is less than 0.1, then update r under the same operating conditions (same average engine speed, same target boost pressure before optimization). BoostAdapt ,

[0118] r BoostAdapt =r BoostAdapt (z).

[0119] If r BoostEva If the value is ≤0.02, then update r under the same operating conditions (same average engine speed, same target boost pressure before optimization). BoostAdapt ,

[0120] r BoostAdapt =-k3×r BoostEva +r BoostAdapt (z), the learning weight coefficient k3 is 0.02.

[0121] The boost pressure self-learning correction coefficient r under other operating conditions BoostAdapt No update. For example, if the engine average speed is 1000 rpm and the average target boost pressure before optimization is 120 kPa, the operating condition is determined. The same operating condition would be when the engine speed is 1000 rpm and the average target boost pressure before optimization is 120 kPa, then update r. BoostAdapt No updates will be made under other operating conditions.

[0122] II. Throttle body effective area self-learning is disabled. This means the activation conditions for throttle body effective area self-learning are not met. For details on the throttle body effective area, please refer to patent number: CN202210345939.6, patent title: Throttle Body Effective Area Calculation Method, Apparatus, Equipment and Readable Storage Medium.

[0123] 3. Activation of carbon canister control is prohibited.

[0124] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0125] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for handling the failure of the electronic pressure relief valve in an exhaust gas turbocharged engine, characterized in that, Includes the following steps: When the electronic pressure relief valve is detected to be unable to open, the following control measures are implemented: Optimized control of the effective throttle area change rate; Reduce target boost pressure; Reduce engine minimum ignition angle efficiency; When the electronic pressure relief valve is detected to be unable to close, the following control measures are implemented: Increase the target boost pressure; Self-learning of effective throttle valve area; Carbon canister control activation is prohibited; The optimized control of the effective throttle area change rate includes the following steps: Determine whether the activation conditions for the throttle effective area change rate optimization control are met; Once the above activation conditions are met, the optimization coefficient for the throttle effective area change rate is determined when the boost control is in closed-loop control and when the boost control is in open-loop control. ; The optimization coefficient of the effective throttle area change rate Compare with 1, and select the minimum value; The optimized throttle effective area change rate was obtained by minimizing the value. : ,in, The change rate of the effective throttle area before optimization; The optimized throttle effective area change rate Used in throttle control; The activation condition for optimizing control by reducing the rate of change of effective throttle valve area is: The conditions for opening the pressure relief valve must be met; The engine did not experience strong knocking; The engine exhaust temperature has not reached its maximum exhaust temperature. Only after all the above conditions are met can the effective throttle area change rate be optimized.

2. The method for handling the failure of the electronic pressure relief valve in a turbocharged engine according to claim 1, characterized in that: Optimization coefficients for determining the effective throttle area change rate when boost control is in closed-loop and open-loop control. The method is as follows: 1) When the boost control is in closed-loop control; 2) When the boost control is in a non-closed-loop control state; The fundamental factors are determined based on engine speed n and intake air density rho entering the cylinder. Based on the gas pressure before the throttle valve and the rate of change of gas pressure before throttle valve Determined correction factor and Both are based on the gas pressure after the throttle valve. and the rate of change of gas pressure after throttle valve Determined correction factor This is the self-learning correction coefficient, which has a default value of 0 and can be continuously updated through self-learning. in Not greater than In the closed loop of boost control, the boost actuator responds quickly and has a poorer pressure relief capability. Therefore, it is even more necessary to reduce the rate of change of the effective throttle area in the closed loop of boost control. The calibration data were all obtained through experimental testing. The calibration was based on the fact that no turbocharger surge occurred after the pressure relief valve failed to open.

3. The method for handling the failure of the electronic pressure relief valve in a turbocharged engine according to claim 2, characterized in that: The calibration method is as follows: First, calibrate the basic factors. , This was obtained through engine bench testing under closed-loop turbocharging conditions, at different engine speeds (n) and different fresh air intake densities (rho) entering the cylinders; specifically: By fixing the gas pressure before the throttle body The rate of change of gas pressure before the throttle valve is 101 kPa. -10 kPa / s, gas pressure after throttle valve The rate of change of gas pressure after the throttle valve is 70 kPa. The calibration was obtained at -6 kPa / s, and the calibration data is as follows: Then, after calibrating the basic factors Then, the correction factor is calibrated. ; The determination method involves conducting engine bench tests under closed-loop turbocharging conditions, with a fixed engine speed n and a fresh air intake density rho entering the cylinder, while simultaneously fixing the gas pressure after the throttle valve. The rate of change of gas pressure after the throttle valve is 70 kPa. The value is -6 kPa / s, obtained by calibrating the inlet gas pressure and the rate of change of inlet gas pressure. The calibration data is as follows: Then calibrate the correction factor. and ; and The determination method involves conducting engine bench tests at a fixed engine speed n and a fresh air intake density rho entering the cylinder, while simultaneously maintaining a fixed gas pressure before the throttle valve. The rate of change of gas pressure before the throttle valve is 101 kPa. The value is -10 kPa / s, which was calibrated by varying the gas pressure after the throttle valve and the rate of change of the gas pressure after the throttle valve. The calibration was performed under closed-loop pressure conditions. The calibration data was obtained under non-closed-loop boost conditions, and the calibration data is as follows: The calibration is as follows: The calibration is as follows: 。 4. The method for handling the failure of the electronic pressure relief valve in a turbocharged engine according to claim 2, characterized in that: Self-learning correction coefficient The default value is 0, and it can continuously learn and update itself, and is saved after the vehicle is powered off. Its learning conditions are as follows: The conditions for opening the pressure relief valve must be met; The engine did not experience strong knocking; The engine exhaust temperature has not reached its maximum exhaust temperature. The ratio of gas pressure after the throttle to gas pressure before the throttle. Not exceeding the preset value; the preset value is related to the engine speed n. The relationship between the preset value and the engine speed n is as follows: After all the above conditions are met, the intake pressure fluctuation characteristic signal within the accumulated time T1 is updated with a self-learning correction coefficient: First, the intake pressure of the actual gas entering the cylinder is subjected to a first-order low-pass filter: in, This represents the actual intake pressure of the gas entering the cylinder. The actual intake pressure of the gas entering the cylinder during the Nth sampling period. This represents the actual intake pressure of the gas entering the cylinder after a first-order low-pass filter. This represents the filtered intake pressure of the actual gas entering the cylinder during the Nth sampling period. Let N be the filtered intake pressure of the actual gas entering the cylinder during the (N-1)th sampling period, where N = 1, 2, 3… Equal to the actual intake pressure of the gas entering the cylinder during the 0th sampling period The start time of the 0th sampling period refers to the moment when the electronic pressure relief valve fails to open. For coefficients: ,in, The number of engine cylinders. Engine speed, The throttle valve outlet intake pressure filtering coefficient; if 1) If it is greater than the preset value A1, where A1 is 4000, then ; 2) If the value is not greater than the preset value A1, but greater than A2, and A2 is not greater than A1, and A2 is 2000, then... ; 3) If the value is not greater than the preset value A2, but greater than A3, where A3 is 1000, then... ; 4) It is not greater than the preset value A3, but greater than A4, where A4 is 500; then ; 5) It is not greater than the preset value A4, but greater than A5, where A5 is 300; then in, It is the correction coefficient for the last self-learning update, that is, the value learned in the last time, and is continuously updated based on its previous value; This is the self-learning correction coefficient, which has a default value of 0 and can be continuously updated through self-learning. The self-learning correction coefficient is updated at most once during each driving cycle.

5. The method for handling the failure of the electronic pressure relief valve in a turbocharged engine according to claim 1, characterized in that: The method to reduce the target boost pressure is as follows: Reduce the target boost pressure to avoid turbocharger surge during sudden pressure drops; optimized target boost pressure correction coefficient. It is determined by both the target boost pressure ratio before optimization and the engine speed; Optimized target boost pressure correction factor The calibration is as follows: The optimized target boost pressure correction factor Multiply by the original target boost pressure to obtain the optimized target boost pressure; The optimized target boost pressure is then used for boost control.

6. The method for handling the failure of the electronic pressure relief valve in a turbocharged engine according to claim 1, characterized in that: The methods to reduce the efficiency of the engine's minimum ignition angle are as follows: Determine whether the triggering condition for reducing the engine's minimum ignition angle efficiency is met; The conditions for the pressure relief valve to open are met; The engine did not experience strong knocking; The engine exhaust temperature has not reached its maximum exhaust temperature. Reduce the engine's minimum ignition angle efficiency so that continuous triggering does not exceed the preset time T1; Once the above conditions are met, optimization to reduce the ignition angle efficiency will be performed. Minimum ignition efficiency correction factor when boost is not in closed-loop mode ; The calibration is as follows: Minimum ignition efficiency correction factor when boosting is in closed-loop mode ; The calibration is as follows: Not greater than That is, when the turbocharger is in a closed loop state, the engine air circuit torque is greater than the engine air circuit torque when the turbocharger is not in a closed loop state, and it is more necessary to reduce the ignition angle efficiency to achieve the accuracy of the ignition circuit torque. When switching from pressurized closed-loop to non-closed-loop mode, or from non-closed-loop to closed-loop mode, the minimum ignition efficiency correction factor... The rate of change shall not exceed ±0.015 / 10ms; in The minimum ignition angle efficiency before optimization. This is the optimized minimum ignition angle efficiency; The optimized minimum ignition angle efficiency is used in the control of minimum ignition angle efficiency.

7. The method for handling the failure of the electronic pressure relief valve in a turbocharged engine according to claim 1, characterized in that: The method to increase the target boost pressure is as follows: First, estimate the gas pressure at the inlet of the pressure relief pipe, where it intersects with the intake pipe. : in, The boost gas pressure before the throttle valve. The flow rate of fresh air entering the cylinder. The area of ​​the pressure relief pipe inlet at the junction of the pressure relief pipe inlet and the intake pipe. The temperature of the boosted gas before the throttle valve. It is the ideal gas constant; Optimized target boost pressure : in, The target boost pressure before optimization. Engine speed, For the requested fire circuit torque, This refers to the actual torque in the fire circuit. This refers to the boost pressure self-learning correction coefficient; where the boost pressure self-learning correction coefficient is... The default value is 0, and it is continuously updated through self-learning throughout the different life cycles of the vehicle and saved after the vehicle is powered off. In the self-learning correction coefficient The value is calibrated to 0, which is determined by the engine speed. Difference coefficient between fire and torque The decision was made jointly, as shown in the table below: The boost pressure self-learning correction coefficient needs to be learned and updated under certain conditions, namely: The boost control is in a closed-loop state; The difference between the optimized target boost pressure and the actual boost pressure shall not exceed the preset value; The throttle is fully open; Engine speed fluctuations do not exceed preset values; The optimized target boost pressure fluctuation does not exceed the preset value; After the above conditions are met, the actual boost pressure is subjected to a first-order low-pass filter: in, This is the actual boost pressure. The actual boost pressure in the Nth sampling period. This is the actual boost pressure after first-order low-pass filtering. This represents the filtered actual boost pressure during the Nth sampling period. The actual boost pressure after filtering in the (N-1)th sampling period, where N = 1, 2, 3… Equal to the actual boost pressure at the 0th sampling period The start time of the 0th sampling period refers to the moment when the electronic pressure relief valve fails to close. ,in The number of engine cylinders. Engine speed, The actual boost pressure filter coefficient; Read the current average engine speed, the average target boost pressure before optimization, and the fluctuation characteristic signal. average : if Then update the corresponding working conditions. , Learning weight coefficient Take 0.1, The boost pressure self-learning correction coefficient is updated for the last learning update, and it can be updated at most once per driving cycle; if Then update the corresponding working conditions. , Learning weight coefficient Take 0.05; if Then update the corresponding working conditions. , ; if Then update the corresponding working conditions. , Learning weight coefficient Take 0.02; Self-learning correction coefficient for boost pressure under other operating conditions No updates.

8. A post-failure treatment system for the electronic pressure relief valve of an exhaust gas turbocharged engine, characterized in that: The processing system adopts the post-failure processing method of the electronic pressure relief valve of the exhaust gas turbocharged engine as described in any one of claims 1-7, which includes an engine controller (EMS), a boost pressure sensor, an atmospheric pressure sensor, an intake pressure sensor, a turbocharger, and an electronic pressure relief valve body. The boost pressure sensor and atmospheric pressure sensor are located after the engine intake compressor. The boost pressure sensor reads the gas pressure at the compressor outlet, and the atmospheric pressure sensor reads the gas pressure in the atmosphere. The intake pressure sensor, turbocharger, and electronic pressure relief valve body are located after the throttle valve. The intake pressure sensor reads the gas pressure after the throttle valve, the turbocharger achieves the intake pressure, and the boost pressure relief valve body allows airflow to flow from the relief valve to the front of the compressor when the intake pressure decreases, preventing airflow from oscillating back and forth within the compressor and causing surge. The boost pressure sensor, atmospheric pressure sensor, and intake pressure sensor transmit the collected data to the engine control system (EMS). The EMS controls the turbocharger intake and the opening and closing of the electronic pressure relief valve, performing optimized control of the throttle effective area change rate, control to reduce the target boost pressure, control to reduce the engine minimum ignition angle efficiency, or control to increase the target boost pressure, disable throttle effective area self-learning control, and disable canister control activation control. It also monitors for pressure relief valve failure and reports a fault code to alert the driver.

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