A method of supercharging control for improving scavenge control

Abstract

The application discloses a supercharging control method for improving scavenging control, comprising the following steps: determining whether a supercharging closed-loop enabling minimum pressure condition is met according to an engine scavenging working condition state; determining whether supercharging closed-loop enabling is enabled after the supercharging closed-loop enabling minimum pressure condition is met; and performing supercharging closed-loop control after the supercharging closed-loop enabling is enabled. The supercharging closed-loop enabling minimum pressure condition is determined according to the engine scavenging working condition state, and the supercharging closed-loop control is performed according to the supercharging closed-loop enabling condition. When the scavenging working condition is activated, the scavenging working performance is further assisted by optimizing the supercharging closed-loop enabling condition.

Description

Technical Field

[0001] This invention belongs to the field of engine control technology, specifically relating to a boost control method for improving scavenging control. Background Technology

[0002] To respond to engine intake boost and torque increase requests, the boost system controls the output to achieve boost by maximizing exhaust energy. Boost control determines engine power and fuel economy. Closed-loop boost control refers to actively controlling the boost actuator to ensure the actual boost pressure matches the target boost pressure. In non-closed-loop boost control, the boost actuator opening is not actively controlled. When there is no intake boost demand, the closed-loop boost control exits. Current technology does not provide perfect boost control performance for turbocharged engines when scavenging is required. Summary of the Invention

[0003] The purpose of this invention is to provide a booster control method to improve scavenging control. When scavenging is activated, the booster closed-loop enable conditions are optimized in conjunction with the scavenging operation, thereby further assisting in achieving the scavenging performance.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is: a booster control method for improving scavenging control, comprising:

[0005] Determine whether the minimum pressure condition for enabling the boost closed loop is met based on the engine scavenging condition.

[0006] Once the minimum pressure condition for enabling the booster closed loop is met, determine whether or not the booster closed loop is enabled.

[0007] After the booster closed-loop is enabled, booster closed-loop control is performed.

[0008] The method for determining whether the minimum pressure condition for enabling the pressurization closed loop is met is as follows:

[0009] 1) When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than the preset value A, the minimum pressure condition for enabling the boost closed loop is met.

[0010] 2) When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than the preset value B; and the difference between the target boost pressure and the actual boost pressure is less than or equal to the preset value C; and the boost closed-loop enable time condition is not met; then the minimum pressure condition for boost closed-loop enable is not met; where, numerically, C > A > B.

[0011] 3) In other cases, the minimum pressure condition for enabling the boost closed loop remains the same as the previous cycle state; among them, the default state is when the vehicle is powered on, and the default state is that the minimum pressure condition for enabling the boost closed loop is not met.

[0012] The criteria for determining whether the boost closed-loop is enabled are as follows:

[0013] 1) The minimum pressure condition for enabling the pressurization closed loop is met;

[0014] 2) The engine speed is greater than the preset engine speed value;

[0015] 3) The electronic pressure relief valve of the turbocharger assembly is not open;

[0016] Only when all the above conditions are met is it determined that the boosting closed loop is enabled; otherwise, it is determined that the boosting closed loop is not enabled.

[0017] The method for determining whether the boost closed-loop enable time condition is met is as follows:

[0018] Determine the scavenging request conditions for the turbocharged direct injection engine;

[0019] Determine the permissible scavenging conditions for the turbocharged direct injection engine. Check whether the turbocharged direct injection engine meets the following conditions: engine speed is within a preset speed range, coolant temperature is within a first preset temperature range, intake air temperature is within a second preset temperature range, fuel octane number is within a preset octane number range, pre-ignition frequency is within a preset pre-ignition frequency range, and catalytic converter temperature is within a third preset temperature range. If yes, the turbocharged direct injection engine is determined to meet the permissible scavenging conditions. If no, the turbocharged direct injection engine is determined to not meet the permissible scavenging conditions.

[0020] If the turbocharged direct injection engine simultaneously meets both the scavenging request condition and the scavenging allow condition, the turbocharged direct injection engine is immediately activated to enter the scavenging activation condition. If the turbocharged direct injection engine only meets one of the scavenging request condition or the scavenging allow condition, it is further determined whether the corresponding process control of the turbocharged direct injection engine is under the control of the scavenging activation condition. If so, the turbocharged direct injection engine is activated for at least the first preset time T1 before exiting the scavenging activation condition. If not, the turbocharged direct injection engine is immediately exited from the scavenging request condition. When the engine enters the scavenging activation condition, it is determined that the turbocharged closed-loop enable condition is met.

[0021] Determine the scavenging request conditions for turbocharged direct injection engines, specifically including:

[0022] Determine if the turbocharger's boosting capability meets the requirements;

[0023] Determine if the high torque request flag for the throttle is activated;

[0024] If the turbocharger's boosting capacity is insufficient and the high torque request flag of the throttle is activated, the turbocharged direct injection engine is determined to meet the scavenging requirement. If the turbocharger's boosting capacity is sufficient and / or the high torque request flag of the throttle is not activated, the turbocharged direct injection engine is determined to not meet the scavenging requirement.

[0025] Determining whether the high torque request flag for the throttle is activated includes:

[0026] Determine the relative percentage of throttle opening to the first preset opening percentage and the second preset opening percentage;

[0027] If the throttle opening percentage is greater than or equal to the first preset opening percentage, the throttle high torque request flag is activated. If the throttle opening percentage is less than the second preset opening percentage, the throttle high torque request flag is not activated. If the throttle opening percentage is less than the first preset opening percentage but greater than or equal to the second preset opening percentage, the activation state of the throttle high torque request flag remains unchanged.

[0028] Determining whether a turbocharger's boosting capability meets the standards includes:

[0029] Calculate the target boost pressure ratio rDesirdRatio and the actual boost pressure ratio rActRatio for the turbocharged direct injection engine, respectively.

[0030] Determine whether rDesirdRatio exceeds the scavenging activation pressure ratio limit rDesirdRatiolimit. If it does, activate the scavenging flag corresponding to rDesirdRatio; otherwise, do not activate it.

[0031] Determine whether the difference between rDesirdRatio and rActRatio exceeds the pressure ratio limit rActRatiolimit. If it does, activate the scavenging flag corresponding to rActRatio; otherwise, do not activate it.

[0032] If at least one of the scavenging flags corresponding to rDesirdRatio and rActRatio is activated, the turbocharger's boosting capability is deemed insufficient.

[0033] The calculation of the target boost pressure ratio rDesirdRatio and the actual boost pressure ratio rActRatio includes:

[0034] Record the target intake pressure, actual intake pressure, and actual gas pressure at the compressor intake end of the turbocharged direct injection engine, respectively. Calculate the target boost pressure ratio rDesirdRatio based on the target intake pressure and the actual gas pressure at the compressor intake end, and calculate the actual boost pressure ratio rActRatio based on the actual intake pressure and the actual gas pressure at the compressor intake end.

[0035] If the duration of the engine scavenging activation condition from the satisfied state to the unsatisfied state is greater than the second preset time T2, and the target throttle opening is lower than K1 times its maximum opening for the first time after the duration of the period from the satisfied state to the unsatisfied state exceeds the second preset time T2, then the boost closed-loop enable time condition is determined to be unsatisfied. The preset coefficient K1 is related to the engine speed and the ratio of the actual outlet pressure to the actual inlet pressure of the throttle.

[0036] When the duration of the engine scavenging activation condition from a satisfied state to a non-satisfied state is less than the second preset time T2, let the difference between the second preset time T2 and the duration be the remaining time T0. Optimize the remaining time T0 to obtain the optimized time T0', and the optimization method is expressed as follows:

[0037] T0′=max{T0×[1-f(Cnt LowKnock )-f(Cnt MediumKnock )-f(Cnt HighKnock )]×(1+r T1 ), 0}

[0038] That is, if engine knock occurs during the process of satisfying the boost closed-loop enable time condition, then the number of knocks, Cnt, is accumulated according to different knock intensities and the corresponding number of knocks for each intensity. LowKnock Cnt MediumKnock Cnt HighKnock Corrections are required; the detonation intensity should include at least low-intensity detonation, medium-intensity detonation, and high-intensity detonation, i.e., Cnt. LowKnock For low-intensity knockout levels, the number of counts and Cnt are accumulated respectively. MediumKnock The number of knocks and Cnt were accumulated for each medium-intensity knock level. HighKnock The number of knock events is accumulated for high-intensity knock events; the time correction factor f(Cnt) is used for low-intensity knock events. LowKnock The time correction factor f(Cnt) under moderate-intensity detonation. MediumKnock ), Time correction factor f(Cnt) under high-intensity detonation HighKnock The basis for determining this is to reduce the risk of detonation and avoid damage to the engine; T0 This is the self-learning coefficient for the remaining time T0, with a default value of 0, and can be saved after the vehicle is powered off.

[0039] The self-learning coefficient r of the remaining time T0 T0 The update conditions are:

[0040] ① If T0-T0′ is greater than the first preset time difference D1, and the first consecutive occurrence count CNT1 exceeds the preset count, then the learning value r of T0 will be adjusted. T0 The self-learning state is the first downward learning state, i.e., r T0 It needs to be reduced, denoted as r.T0 =r T0 (z)-0.02, where r T0 (z) is the learning value stored at the time T0 of the last learning, while CNT1 is cleared. The newly stored learning value is used when this situation is judged next time.

[0041] ② If T0-T0′ is less than or equal to the second preset time difference D2, and the second consecutive occurrence count CNT2 exceeds the preset count, then the time T0 self-learning state is set to the first upward learning state, i.e., r T0 It needs to be increased, denoted as r. T0 =r T0 (z)+0.01, the newly learned value is used when judging this situation the next time it is entered;

[0042] ③ In other cases, r T0 Remain unchanged;

[0043] The priority of update conditions ①-③ decreases progressively, with update condition ① having the highest priority and update condition ③ having the lowest priority.

[0044] The initial value of the second preset time T2 and the calibration conditions of the preset coefficient K1 are as follows: within the third preset time T3 after the activation and deactivation of the boost closed-loop, if the throttle inlet intake pressure is stable, then calibration is performed; the criterion for judging the stability of the throttle inlet intake pressure is as follows:

[0045]

[0046] Where, p pre p is the intake pressure at the throttle valve inlet. pre (N) represents the throttle inlet intake pressure during the Nth sampling period, p preFilter p is the throttle inlet pressure after first-order low-pass filtering. preFilte ( r N) represents the filtered throttle inlet pressure during the Nth sampling period, p preFilte ( r N-1) represents the filtered throttle inlet pressure during the (N-1)th sampling period, where N = 1, 2, 3, ..., p preFilter (0) equals the throttle inlet pressure p at the 0th sampling period. pre (0); Δt is the sampling period interval; KMan For coefficients, it is expressed as: Where m is the number of engine cylinders, n is the engine speed, and k pre This refers to the throttle inlet pressure filter coefficient.

[0047] In |p pre (N)-p preFilter(N)|<min[p pre (N), p preFilter (N)]×r preLim Once the conditions are met, it indicates that the throttle inlet pressure is in a relatively stable state.

[0048] A computer device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, performs the steps of the method as described in any of the preceding claims.

[0049] A computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the method as described in any of the preceding claims.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] This invention determines the minimum pressure condition for enabling the boost closed loop by the engine scavenging condition, and performs boost closed loop control based on the boost closed loop enabling condition. When the scavenging condition is activated, it optimizes the boost closed loop enabling condition in conjunction with the scavenging operation, thereby further assisting in achieving the scavenging performance. Attached Figure Description

[0052] Figure 1 This is a flowchart illustrating an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of the architecture of the low-voltage EGR system in an embodiment of the present invention;

[0054] In the diagram, 1-air filter, 2-mixing valve, 3-compressor, 4-throttle valve, 5-engine, 6-turbine, 7-catalyst, 8-particulate filter, 9-EGR cooler, 10-EGR valve, 11-temperature sensor, 12-differential pressure sensor. Detailed Implementation

[0055] 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. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0056] A boost control method for improving scavenging control is applied to a system structure with a low-pressure EGR system and an exhaust gas turbocharger system. The system structure includes an air filter 1, a mixing valve 2, a compressor 3, a throttle valve 4, an engine 5, a turbine 6, a catalyst 7, a particulate filter 8, an EGR cooler 9, an EGR valve 10, a temperature sensor 11, and a differential pressure sensor 12.

[0057] The turbocharger compressor compresses fresh air for boosting; the turbocharger turbine controls the turbine's efficiency by adjusting the opening of the turbocharger's exhaust bypass valve, thus achieving different boosting capacities. Compared to the non-low-pressure EGR system, the low-pressure EGR system adds the following components: EGR cooler 9, EGR temperature sensor, EGR valve 10, EGR differential pressure sensor, and mixing valve 2. Mixing valve 2 regulates the outlet pressure of EGR valve 10, increasing the pressure differential across EGR valve 10 and improving the EGR rate. EGR cooler 9 cools the exhaust gas, facilitating increased exhaust gas flow and reduced exhaust gas temperature. EGR valve 10 throttles the flow of exhaust gas into the cylinder. The EGR temperature sensor detects the temperature of the exhaust gas entering EGR valve 10. The EGR differential pressure sensor detects the pressure at the EGR inlet and outlet. The low-pressure EGR system architecture is as follows: Figure 2 As shown.

[0058] The technical solution of this invention is as follows:

[0059] Example 1:

[0060] A booster control method to improve scavenging control, such as Figure 1 As shown, it includes:

[0061] S1. Determine whether the minimum pressure condition for enabling the boost closed loop is met based on the engine scavenging condition.

[0062] S2. Once the minimum pressure condition for enabling the booster closed loop is met, determine whether the booster closed loop is enabled.

[0063] S3. After enabling the boost closed loop, perform boost closed loop control.

[0064] The method for determining whether the minimum pressure condition for enabling the pressurization closed loop is met is as follows:

[0065] 1) When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than a preset value A, where A = C1, and C1 is taken as 2 kPa in this embodiment, the minimum pressure condition for enabling the boost closed loop is satisfied.

[0066] 2) When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than the preset value B, B = C2, where C2 is -1 kPa in this embodiment; and the difference between the target boost pressure and the actual boost pressure is less than or equal to the preset value C, where C is 3.5 kPa in this embodiment; and the boost closed-loop enabling time condition is not met; then the minimum pressure condition for boost closed-loop enabling is not met; where, numerically, C > A > B;

[0067] 3) In other cases, the minimum pressure condition for enabling the boost closed loop remains the same as the previous cycle state; among them, the default state is when the vehicle is powered on, and the default state is that the minimum pressure condition for enabling the boost closed loop is not met.

[0068] The criteria for determining whether the boost closed-loop is enabled are as follows:

[0069] 1) The minimum pressure condition for enabling the pressurization closed loop is met;

[0070] 2) The engine speed is greater than the preset engine speed value, which is 600 rpm in this embodiment;

[0071] 3) The electronic pressure relief valve of the turbocharger assembly is not open;

[0072] Only when all the above conditions are met is it determined that the boosting closed loop is enabled; otherwise, it is determined that the boosting closed loop is not enabled.

[0073] The method for determining whether the boost closed-loop enable time condition is met is as follows:

[0074] Determine the scavenging request conditions for the turbocharged direct injection engine;

[0075] Determine the permissible scavenging conditions for the turbocharged direct injection engine. Check whether the turbocharged direct injection engine meets the following conditions: engine speed is within a preset speed range, coolant temperature is within a first preset temperature range, intake air temperature is within a second preset temperature range, fuel octane number is within a preset octane number range, pre-ignition frequency is within a preset pre-ignition frequency range, and catalytic converter temperature is within a third preset temperature range. If yes, the turbocharged direct injection engine is determined to meet the permissible scavenging conditions. If no, the turbocharged direct injection engine is determined to not meet the permissible scavenging conditions.

[0076] If the turbocharged direct injection engine simultaneously meets both the scavenging request condition and the scavenging allow condition, the turbocharged direct injection engine is immediately activated to enter the scavenging activation condition. If the turbocharged direct injection engine only meets one of the scavenging request condition or the scavenging allow condition, it is further determined whether the corresponding process control of the turbocharged direct injection engine is under the control of the scavenging activation condition. If so, the turbocharged direct injection engine is activated for at least the first preset time T1 before exiting the scavenging activation condition. If not, the turbocharged direct injection engine is immediately exited from the scavenging request condition. When the engine enters the scavenging activation condition, it is determined that the turbocharged closed-loop enable condition is met.

[0077] Determine the scavenging request conditions for turbocharged direct injection engines, specifically including:

[0078] Determine if the turbocharger's boosting capability meets the requirements;

[0079] Determine if the high torque request flag for the throttle is activated;

[0080] If the turbocharger's boosting capacity is insufficient and the high torque request flag of the throttle is activated, the turbocharged direct injection engine is determined to meet the scavenging requirement. If the turbocharger's boosting capacity is sufficient and / or the high torque request flag of the throttle is not activated, the turbocharged direct injection engine is determined to not meet the scavenging requirement.

[0081] Determining whether the high torque request flag for the throttle is activated includes:

[0082] Determine the relative percentage of throttle opening to the first preset opening percentage and the second preset opening percentage;

[0083] If the throttle opening percentage is greater than or equal to the first preset opening percentage, the throttle high torque request flag is activated. If the throttle opening percentage is less than the second preset opening percentage, the throttle high torque request flag is not activated. If the throttle opening percentage is less than the first preset opening percentage but greater than or equal to the second preset opening percentage, the activation state of the throttle high torque request flag remains unchanged.

[0084] Determining whether a turbocharger's boosting capability meets the standards includes:

[0085] Calculate the target boost pressure ratio rDesirdRatio and the actual boost pressure ratio rActRatio for the turbocharged direct injection engine, respectively.

[0086] Determine whether rDesirdRatio exceeds the scavenging activation pressure ratio limit rDesirdRatiolimit. If it does, activate the scavenging flag corresponding to rDesirdRatio; otherwise, do not activate it.

[0087] Determine whether the difference between rDesirdRatio and rActRatio exceeds the pressure ratio limit rActRatiolimit. If it does, activate the scavenging flag corresponding to rActRatio; otherwise, do not activate it.

[0088] If at least one of the scavenging flags corresponding to rDesirdRatio and rActRatio is activated, the turbocharger's boosting capability is deemed insufficient.

[0089] The calculation of the target boost pressure ratio rDesirdRatio and the actual boost pressure ratio rActRatio includes:

[0090] Record the target intake pressure, actual intake pressure, and actual gas pressure at the compressor intake end of the turbocharged direct injection engine, respectively. Calculate the target boost pressure ratio rDesirdRatio based on the target intake pressure and the actual gas pressure at the compressor intake end, and calculate the actual boost pressure ratio rActRatio based on the actual intake pressure and the actual gas pressure at the compressor intake end.

[0091] If the duration of the engine scavenging activation condition from a satisfied state to a dissatisfied state is greater than the second preset time T2, and the target throttle opening is lower than K1 times its maximum opening for the first time after the duration of the duration from a satisfied state to a dissatisfied state exceeds the second preset time T2, then the boost closed-loop enable time condition is determined to be unsatisfactory. Among them, the preset coefficient K1 is related to the engine speed and the ratio of the actual outlet pressure to the actual inlet pressure of the throttle (referred to as the throttle pressure ratio) (its value is shown in Table 1 in this embodiment). At a certain engine speed, the smaller the throttle pressure ratio, the better the throttle can adjust the intake pressure. Therefore, the smaller the throttle pressure ratio, the smaller the preset coefficient K1, so as to quickly respond to the torque increase.

[0092] Table 1

[0093]

[0094] When the duration of the engine scavenging activation condition from a satisfied state to a non-satisfied state is less than the second preset time T2, let the difference between the second preset time T2 and the duration be the remaining time T0. T0 must be less than or equal to T2. Optimize the remaining time T0 to obtain the optimized time T0'. The optimization method is expressed as follows:

[0095] T0′=max{T0×[1-f(Cnt LowKnock )-f(Cnt MediumKnock )-f(Cnt HighKnock )]×(1+r T1 ), 0}

[0096] That is, if engine knock occurs during the process of satisfying the boost closed-loop enable time condition, then the number of knocks, Cnt, is accumulated according to different knock intensities and the corresponding number of knocks for each intensity. LowKnock Cnt MediumKnock Cnt HighKnock Corrections are required; the detonation intensity should include at least low-intensity detonation, medium-intensity detonation, and high-intensity detonation, i.e., Cnt. LowKnock For low-intensity knockout levels, the number of counts and Cnt are accumulated respectively. MediumKnock The number of knocks and Cnt were accumulated for each medium-intensity knock level. HighKnock The number of knock events is accumulated for high-intensity knock events; the time correction factor f(Cnt) is used for low-intensity knock events. LowKnockThe time correction factor f(Cnt) under moderate-intensity detonation. MediumKnock ), Time correction factor f(Cnt) under high-intensity detonation HighKnock The determination of the values ​​is based on reducing the risk of detonation and avoiding damage to the engine. Based on this, the specific calibration values ​​in this embodiment are shown in Tables 2, 3 and 4:

[0097] Table 2

[0098] <![CDATA[Cnt LowKnock ]]> 0 3 5 7 12 15 <![CDATA[f(Cnt LowKnock )]]> 0 0 0.01 0.02 0.04 0.05

[0099] Table 3

[0100] <![CDATA[Cnt MediumKnock ]]> 0 3 5 7 12 15 <![CDATA[f(Cnt MediumKnock )]]> 0 0.02 0.05 0.06 0.08 0.1

[0101] Table 4

[0102] <![CDATA[Cnt HighKnock ]]> 0 1 3 7 10 12 <![CDATA[f(Cnt HighKnock )]]> 0 0.02 0.05 0.08 0.1 0.12

[0103] r T0 This is the self-learning coefficient for the remaining time T0, with a default value of 0, and can be saved after the vehicle is powered off.

[0104] The self-learning coefficient r of the remaining time T0 T0 The update conditions are:

[0105] ① If T0-T0′ is greater than the first preset time difference D1 (0.08s in this embodiment, indicating that the time adjustment is too large due to knocking or pre-ignition), and the first consecutive occurrence count CNT1 is initially 0 (which can be saved after the vehicle is powered off) exceeds the preset number (5 in this embodiment), then the T0 learning value r is set. T0 The self-learning state is the first downward learning state, i.e., r T0 It needs to be reduced, denoted as r. T0 =r T0 (z)-0.02, where r T0 (z) is the learning value stored at the time T0 of the last learning, while CNT1 is cleared. The newly stored learning value is used when this situation is judged next time.

[0106] ② If T0-T0′ is less than or equal to the second preset time difference D2 (0.03s in this embodiment, indicating that knocking or pre-ignition is unlikely), and the second consecutive occurrence count CNT2 (initial value 0, which can be saved after the vehicle is powered off) exceeds the preset count, then the time T0 self-learning state is set to the first upward learning state, i.e., r T0 It needs to be increased, denoted as r. T0 =r T0 (z)+0.01, the newly learned value is used when judging this situation the next time it is entered;

[0107] ③ In other cases, rT0 Remain unchanged;

[0108] The priority of update conditions ①-③ decreases progressively, with update condition ① having the highest priority and update condition ③ having the lowest priority.

[0109] The initial value of the second preset time T2 and the calibration conditions of the preset coefficient K1 are as follows: within the third preset time T3 (0.5s in this embodiment) after the start of boost closed-loop enable activation and deactivation, if the throttle inlet intake pressure is stable, then calibration is performed; the criterion for judging the stability of the throttle inlet intake pressure is:

[0110]

[0111] Where, p pre p is the intake pressure at the throttle valve inlet. pre (N) represents the throttle inlet intake pressure during the Nth sampling period, p preFilter p is the throttle inlet pressure after first-order low-pass filtering. preFilte ( r N) represents the filtered throttle inlet pressure during the Nth sampling period, p preFilter (N-1) represents the filtered throttle inlet pressure during the (N-1)th sampling period, where N = 1, 2, 3, ..., p preFilter (0) equals the throttle inlet pressure p at the 0th sampling period. pre (0); Δt is the sampling period interval, which is 10ms in this embodiment; KMan For coefficients, it is expressed as: (In this embodiment, the engine has 4 cylinders, k) pre 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. pre (This reduces calibration testing work), where m is the number of engine cylinders, n is the engine speed, and k pre The throttle inlet pressure filtering coefficient is 0.1 in this embodiment.

[0112] In |p pre (N)-p preFilter (N)|<min[p pre (N), p preFilter (N)]×r preLim Once the condition is met, it indicates that the throttle inlet pressure is in a relatively stable state (throttle inlet pressure fluctuations are small). Wherein, r preLim In this embodiment, 0.1 is used.

[0113] In the initial state of vehicle power-on, the boost closed-loop enable time condition is not met.

[0114] Example 2:

[0115] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, performs the steps of the method as described in any of the preceding claims.

[0116] Example 3:

[0117] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method as described in any of the preceding claims.

[0118] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A booster control method for improving scavenging control, characterized in that, include: Determine whether the minimum pressure condition for enabling the boost closed loop is met based on the engine scavenging condition. Once the minimum pressure condition for enabling the booster closed loop is met, determine whether or not the booster closed loop is enabled. After enabling the boost closed-loop control, boost closed-loop control is performed. The method for determining whether the minimum pressure condition for enabling the pressurization closed loop is met is as follows: 1) When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than the preset value A, the minimum pressure condition for enabling the boost closed loop is met. 2) When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than the preset value B; and the difference between the target boost pressure and the actual boost pressure is less than or equal to the preset value C; and the boost closed-loop enable time condition is not met; then the minimum pressure condition for boost closed-loop enable is not met; where, numerically, C > A > B. 3) Under other circumstances, the minimum pressure condition for enabling the boost closed loop remains the same as the previous cycle state; among them, the default state is when the vehicle is powered on, and the default state is that the minimum pressure condition for enabling the boost closed loop is not met.

2. The booster control method for improving scavenging control according to claim 1, characterized in that, The criteria for determining whether the boost closed-loop is enabled are as follows: 1) The minimum pressure condition for enabling the pressurization closed loop is met; 2) The engine speed is greater than the preset engine speed value; 3) The electronic pressure relief valve of the turbocharger assembly is not open; Only when all the above conditions are met is it determined that the boosting closed loop is enabled; otherwise, it is determined that the boosting closed loop is not enabled.

3. The booster control method for improving scavenging control according to claim 1, characterized in that, The method for determining whether the boost closed-loop enable time condition is met is as follows: Determine the scavenging request conditions for the turbocharged direct injection engine; Determine the permissible scavenging conditions for the turbocharged direct injection engine. Check whether the turbocharged direct injection engine meets the following conditions: engine speed is within a preset speed range, coolant temperature is within a first preset temperature range, intake air temperature is within a second preset temperature range, fuel octane number is within a preset octane number range, pre-ignition frequency is within a preset pre-ignition frequency range, and catalytic converter temperature is within a third preset temperature range. If yes, the turbocharged direct injection engine is determined to meet the permissible scavenging conditions. If no, the turbocharged direct injection engine is determined to not meet the permissible scavenging conditions. If the turbocharged direct injection engine simultaneously meets both the scavenging request condition and the scavenging allow condition, the turbocharged direct injection engine is immediately activated to enter the scavenging activation condition. If the turbocharged direct injection engine only meets one of the scavenging request condition or the scavenging allow condition, it is further determined whether the corresponding process control of the turbocharged direct injection engine is under the control of the scavenging activation condition. If so, the turbocharged direct injection engine is activated for at least the first preset time T1 before exiting the scavenging activation condition. If not, the turbocharged direct injection engine is immediately exited from the scavenging request condition. When the engine enters the scavenging activation condition, it is determined that the boost closed-loop enable condition is met. Determine the scavenging request conditions for turbocharged direct injection engines, specifically including: Determine if the turbocharger's boosting capability meets the requirements; Determine if the high torque request flag for the throttle is activated; If the turbocharger's boosting capacity is insufficient and the high torque request flag of the throttle is activated, the turbocharged direct injection engine is determined to meet the scavenging requirement. If the turbocharger's boosting capacity is sufficient and / or the high torque request flag of the throttle is not activated, the turbocharged direct injection engine is determined to not meet the scavenging requirement. Determining whether the high torque request flag for the throttle is activated includes: Determine the relative percentage of throttle opening to the first preset opening percentage and the second preset opening percentage; If the throttle opening percentage is greater than or equal to the first preset opening percentage, the throttle high torque request flag is activated. If the throttle opening percentage is less than the second preset opening percentage, the throttle high torque request flag is not activated. If the throttle opening percentage is less than the first preset opening percentage but greater than or equal to the second preset opening percentage, the activation state of the throttle high torque request flag remains unchanged. Determining whether a turbocharger's boosting capability meets the standards includes: Calculate the target boost pressure ratio rDesirdRatio and the actual boost pressure ratio rActRatio for the turbocharged direct injection engine, respectively. Determine whether rDesirdRatio exceeds the scavenging activation pressure ratio limit rDesirdRatiolimit. If it does, activate the scavenging flag corresponding to rDesirdRatio; otherwise, do not activate it. Determine whether the difference between rDesirdRatio and rActRatio exceeds the pressure ratio limit rActRatiolimit. If it does, activate the scavenging flag corresponding to rActRatio; otherwise, do not activate it. If at least one of the scavenging flags corresponding to rDesirdRatio and rActRatio is activated, the turbocharger's boosting capability is deemed insufficient. The calculation of the target boost pressure ratio rDesirdRatio and the actual boost pressure ratio rActRatio includes: Record the target intake pressure, actual intake pressure, and actual gas pressure at the compressor intake end of the turbocharged direct injection engine, respectively. Calculate the target boost pressure ratio rDesirdRatio based on the target intake pressure and the actual gas pressure at the compressor intake end, and calculate the actual boost pressure ratio rActRatio based on the actual intake pressure and the actual gas pressure at the compressor intake end.

4. The booster control method for improving scavenging control according to claim 3, characterized in that, If the duration of the engine scavenging activation condition from the satisfied state to the unsatisfied state is greater than the second preset time T2, and the target throttle opening is lower than K1 times its maximum opening for the first time after the duration of the period from the satisfied state to the unsatisfied state exceeds the second preset time T2, then the boost closed-loop enable time condition is determined to be unsatisfied. The preset coefficient K1 is related to the engine speed and the ratio of the actual outlet pressure to the actual inlet pressure of the throttle.

5. The booster control method for improving scavenging control according to claim 4, characterized in that, When the duration of the engine scavenging activation condition from a satisfied state to a non-satisfied state is less than the second preset time T2, let the difference between the second preset time T2 and the duration be the remaining time T0. Optimize the remaining time T0 to obtain the optimized time T0', and the optimization method is expressed as follows: That is, if engine knock occurs during the process of satisfying the boost closed-loop enable time condition, then the number of counts will be accumulated according to different knock intensities and the corresponding counts for different knock intensities. , , Corrections should be made; the detonation intensity should include at least low-intensity detonation, medium-intensity detonation, and high-intensity detonation, i.e. The number of knock events for low-intensity levels is accumulated separately. The number of knocks for medium intensity levels is accumulated separately. The number of knocks is accumulated for each high-intensity level. Time correction factor under low-intensity knock Time correction factor under moderate intensity knock shock Time correction factor under high-intensity detonation The basis for this determination is to reduce the risk of detonation and avoid damage to the engine; This is the self-learning coefficient for the remaining time T0, with a default value of 0, and can be saved after the vehicle is powered off.

6. The booster control method for improving scavenging control according to claim 5, characterized in that, Self-learning coefficient of remaining time T0 The update conditions are: ①If If the time difference is greater than the first preset time difference D1, and the first consecutive occurrence count CNT1 exceeds the preset number, then the T0 learning value will be adjusted. The self-learning state is the first downward learning state, that is... It needs to be reduced, expressed as ,in, The learning value is the time T0 of the last learning and storage, and CNT1 is cleared to zero. The newly learned and stored learning value is used when this situation is judged next time. ②If If the time difference is less than or equal to the second preset time difference D2, and the second consecutive occurrence count CNT2 exceeds the preset count, then the time T0 self-learning state is changed to the first upward learning state, i.e. It needs to be increased, expressed as The newly learned values ​​are used when judging this situation the next time it is encountered; ③ In other cases, Remain unchanged; The priority of update conditions ①-③ decreases progressively, with update condition ① having the highest priority and update condition ③ having the lowest priority.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1-6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1-6.

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