Control method for improving activation condition of pressurization closed loop

Abstract

The invention discloses a control method for improving a pressurization closed-loop activation condition. The control method comprises the steps that a minimum pressurization pressure initial value is obtained; obtaining a minimum boost pressure filtering value according to the minimum boost pressure initial value; determining the minimum boost pressure as a minimum boost pressure initial value or a minimum boost pressure filtering value according to the power performance requirement of the engine; and whether pressurization closed loop enabling is allowed or not is judged according to the minimum pressurization pressure. By means of the control method, the supercharging control effect can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and particularly to a control method for improving the activation conditions of a supercharging closed loop. Background Art

[0002] In order to respond to the engine intake supercharging and engine torque increase requests, the supercharging system controls to achieve more exhaust energy for supercharging. The supercharging control determines the power performance and fuel economy of the engine, etc. The supercharging closed-loop control refers to actively controlling the supercharger actuator to achieve the follow-up of the actual supercharging pressure and the target supercharging pressure. When in non-closed-loop supercharging control, the opening degree of the supercharger actuator is not actively controlled. When there is no intake supercharging demand, the supercharging closed-loop control will be exited.

[0003] The prior art one proposed a method for determining the target supercharging pressure of an exhaust gas turbocharged engine. In this method, a scheme for determining the target supercharging pressure based on the intake pressure demand was proposed. The prior art two proposed an exhaust gas turbo engine supercharging closed-loop adaptive system and control method. In this method, when the engine controller receives a supercharging closed-loop request, it outputs a duty cycle signal for controlling the wastegate valve of the supercharger assembly, so as to control the actual supercharging pressure of the supercharger assembly to follow the target supercharging pressure of the supercharger. At the same time, during the process of the actual supercharging pressure of the supercharger assembly following the target supercharging pressure of the supercharger, machine learning for the closed-loop control of the supercharger assembly is performed to update the integral term in the PID control at the target supercharging ratio and engine speed.

[0004] However, none of the above prior arts proposed a scheme for optimizing the control of the supercharging closed-loop activation conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a control method for improving the activation conditions of a supercharging closed loop, so as to realize the optimization of the control of the supercharging closed-loop activation conditions and improve the supercharging control effect.

[0006] To solve the above technical problems, the present invention provides a control method for improving the activation conditions of a supercharging closed loop, including: Obtaining an initial value of the minimum supercharging pressure; Obtaining a filtered value of the minimum supercharging pressure according to the initial value of the minimum supercharging pressure; Determining the minimum supercharging pressure as the initial value of the minimum supercharging pressure or the filtered value of the minimum supercharging pressure according to the engine power performance requirements; Judging whether to allow the supercharging closed-loop enable according to the minimum supercharging pressure.

[0007] According to the above solution, the initial value of the minimum supercharging pressure is obtained according to the minimum supercharging pressure base value, the first minimum supercharging pressure correction coefficient, the outlet pressure of the mixing valve, and the third minimum supercharging pressure correction coefficient; Among them, the basic value of the minimum supercharging pressure is determined according to the engine speed and the outlet pressure of the mixing valve; The first correction coefficient of the minimum supercharging pressure is determined according to the outlet gas temperature of the mixing valve; The third correction coefficient of the minimum supercharging pressure is obtained from the filtered value of the throttle pressure ratio and the filtered value of the predicted throttle pressure ratio; the filtered value of the throttle pressure ratio is obtained by filtering the throttle pressure ratio, and the filtered value of the predicted throttle pressure ratio is obtained by filtering the predicted throttle pressure ratio. The throttle pressure ratio is the ratio of the outlet gas pressure of the throttle to the inlet gas pressure of the throttle, and the predicted throttle pressure ratio is the ratio of the outlet gas pressure of the throttle to the predicted value of the inlet gas pressure of the throttle.

[0008] According to the above scheme, the relationship between the basic value of the minimum supercharging pressure and the engine speed and the outlet pressure of the mixing valve is determined by calibration; The relationship between the first correction coefficient of the minimum supercharging pressure and the outlet gas temperature of the mixing valve is determined by calibration; The relationship between the third correction coefficient of the minimum supercharging pressure and the filtered value of the throttle pressure ratio and the filtered value of the predicted throttle pressure ratio is determined by calibration.

[0009] According to the above scheme, the predicted value of the inlet gas pressure of the throttle is obtained from the inlet gas pressure of the throttle and the predicted change amount of the inlet gas pressure of the throttle; The predicted change amount of the inlet gas pressure of the throttle is determined by the predicted value of the inlet gas pressure of the throttle at different sampling periods, the sampling period, and the time constant.

[0010] According to the above scheme, the method for obtaining the filtered value of the throttle pressure ratio includes: Obtaining the filtered value of the throttle pressure ratio according to the throttle pressure ratio, the filtered value of the throttle pressure ratio in the previous sampling period, the sampling time, and the first filtering time; Among them, the first filtering time is obtained according to the engine speed; The method for obtaining the filtered value of the predicted throttle pressure ratio includes: Obtaining the filtered value of the throttle pressure ratio according to the predicted throttle pressure ratio, the filtered value of the predicted throttle pressure ratio in the previous sampling period, the sampling time, and the second filtering time; Among them, the second filtering time is obtained according to the engine speed.

[0011] According to the above scheme, the method for obtaining the filtered value of the minimum supercharging pressure includes: Obtaining the filtered value of the minimum supercharging pressure according to the initial value of the minimum supercharging pressure, the filtered value of the minimum supercharging pressure in the previous sampling period, the sampling time, and the minimum supercharging pressure filtering time.

[0012] According to the above scheme, the method for obtaining the minimum supercharging pressure filtering time is as follows: Determine the first parameter based on the inlet pressure of the mixing valve and the inlet pressure of the mixing valve after first-order low-pass filtering; Determine the second parameter based on the actual EGR rate and the actual EGR rate after first-order low-pass filtering; When the first parameter exceeds the preset value and lasts for a certain period of time, or when the second parameter exceeds the preset value and lasts for a certain period of time, determine the minimum supercharging pressure filtering time according to the mixing valve inlet pressure fluctuation correction coefficient and the actual EGR rate fluctuation correction coefficient; otherwise, take the preset value for the minimum supercharging pressure filtering time; and the minimum supercharging pressure filtering time is limited within the preset range; Among them, the mixing valve inlet pressure fluctuation correction coefficient is determined according to the first parameter; the actual EGR rate fluctuation correction coefficient is determined according to the second parameter.

[0013] According to the above solution, the method for determining the minimum supercharging pressure as the minimum supercharging pressure initial value or the minimum supercharging pressure filtering value according to the engine power performance requirement includes: When the engine power demand is too large, make the minimum supercharging pressure equal to the minimum supercharging pressure initial value; otherwise, make the minimum supercharging pressure equal to the minimum supercharging pressure filtering value; The method for judging whether the engine power demand is too large includes: 1) The engine requested torque is not less than a certain percentage of the maximum torque that the current power system can provide; 2) The throttle pedal opening is greater than or equal to a certain percentage; 3) The throttle valve opening exceeds a certain percentage; 4) The difference between the engine basic ignition angle efficiency and the actual ignition angle efficiency does not exceed the preset value; 5) The engine does not have any knocking and does not have pre-ignition; When the above 1) - 5) are all satisfied and last for more than the preset time, it is considered that the engine power demand is too large.

[0014] According to the above solution, the method for judging whether to allow supercharging closed-loop enabling based on the minimum supercharging pressure includes: When the following conditions are met simultaneously, allow supercharging closed-loop enabling: 1) The minimum pressure condition for supercharging closed-loop enabling is satisfied; 2) The engine speed is greater than the preset value; 3) The electronic pressure relief valve of the turbocharger assembly is not opened; Among them, the method for judging whether the minimum pressure condition for supercharging closed-loop enabling is satisfied includes: When the difference between the target compressor outlet pressure and the minimum supercharging pressure is greater than the preset value, the minimum pressure condition for supercharging closed-loop enabling is satisfied; When the difference between the outlet pressure of the target compressor and the minimum supercharging pressure is within a preset range, the minimum pressure condition for enabling the supercharging closed-loop is not satisfied; In other cases, the minimum pressure condition for enabling the supercharging closed-loop maintains the previous state; and when the vehicle is powered on, the minimum pressure condition for enabling the supercharging closed-loop is not satisfied.

[0015] The present invention also provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that when the processor executes the computer program, the steps of the control method for improving the supercharging closed-loop activation condition described above are implemented.

[0016] Beneficial effects The present invention controls the minimum supercharging pressure from the perspective of improving the coordinated control of the throttle valve and supercharging, and at the same time optimizes the supercharging pressure control accuracy brought by the pressure fluctuation of the mixing valve and the EGR rate fluctuation to the supercharging entry, thereby improving the supercharging control effect. Description of the drawings

[0017] Figure 1 is a schematic diagram of the low-pressure EGR system architecture according to Embodiment 1 of the present invention; Figure 2 is a logic block diagram of the control method for improving the supercharging closed-loop activation condition according to Embodiment 1 of the present invention; Figure 3 is a flowchart of the control method for improving the supercharging closed-loop activation condition according to Embodiment 1 of the present invention. Detailed implementation manners

[0018] To make the purposes, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0019] Embodiment 1: Patent CN201910988050.8, "Exhaust Gas Turbo Engine Supercharging Closed - Loop Adaptive System and Control Method", mentions the acquisition of the minimum supercharging pressure. The opening condition of the exhaust gas bypass valve requires that the sum of the exhaust back pressure and the pressure of the supercharged gas is greater than the spring pre - tightening force of the exhaust gas bypass valve. The supercharged gas pressure needs to be greater than a certain calibrated value (referred to as the minimum supercharging pressure) before it can overcome the spring pre - tightening force. However, 1) with the introduction of the mixing valve in the low - pressure EGR system, the operation of the mixing valve and the compressor of the supercharging system will affect each other. Therefore, it is necessary to consider the outlet pressure of the mixing valve rather than the atmospheric pressure; 2) The existing electric actuator controls the exhaust gas bypass valve. At this time, it does not need to overcome the spring pre - tightening force like a traditional exhaust gas turbocharger. However, in order to consider the response accuracy of pressure control by preferentially passing through the throttle valve (ultimately, both the throttle valve and the supercharger are for controlling the intake pressure, but the throttle valve has a higher control responsiveness, so control is preferentially carried out through the throttle valve), there is still a minimum supercharging pressure for supercharging control enabling. When the target supercharging pressure is too small, the supercharger does not need to work, and the intake pressure can be achieved only by adjusting the throttle valve. When the throttle valve pressure regulation ability is insufficient, the supercharger needs to be activated for control.

[0020] See Figure 1 , the system structure with a low - pressure EGR system and an exhaust gas turbocharging system includes an air filter, a mixing valve, a supercharger compressor, a throttle valve, an engine, a supercharger turbine, a catalytic converter, a particulate trap, an EGR cooler, an EGR valve, an EGR temperature sensor, an EGR differential pressure sensor, a flow meter, and a linear oxygen sensor.

[0021] Among them, the supercharger compressor compresses fresh air for supercharging; The supercharger turbine controls the working efficiency of the turbine by controlling the opening degree of the exhaust gas bypass valve of the supercharger (using an electric actuator to control the exhaust gas bypass valve), thereby achieving different supercharging capabilities; Compared with the non - low - pressure EGR system, the additional components of the low - pressure EGR system are: an EGR cooler, an EGR temperature sensor, an EGR valve, an EGR differential pressure sensor, a mixing valve, a flow meter, and an oxygen sensor; Among them, the flow meter is installed between the air filter and the mixing valve and is used to detect the flow rate of fresh air entering the engine. It is an option (the meaning of option is that it is determined whether to install according to the vehicle model. It can be selected or not. If not selected, an estimation method is used to obtain the corresponding information); The mixing valve is used to adjust the pressure at the outlet of the EGR valve, increase the pressure difference across the EGR valve, and increase the EGR rate; The oxygen sensor, an option, is installed between the compressor and the throttle valve, close to the throttle valve, and is used to detect the flow rate of the air - fuel mixture entering the cylinder; EGR cooler, used to cool the exhaust gas, facilitating an increase in the exhaust gas flow rate and a reduction in the exhaust gas temperature; EGR valve, with a throttling effect, controlling the exhaust gas flow rate entering the cylinder; EGR temperature sensor, used to detect the exhaust gas temperature entering the EGR valve; EGR differential pressure sensor, used to detect the pressures at the EGR inlet and outlet.

[0022] See Figure 2 、 Figure 3 , based on the above system, in view of the problems existing in the above prior art, this embodiment discloses a control method for improving the supercharging closed-loop activation condition, including the following steps: S1. Obtain the initial value of the minimum supercharging pressure; S2. Obtain the filtered value of the minimum supercharging pressure according to the initial value of the minimum supercharging pressure; S3. Determine the minimum supercharging pressure as the initial value of the minimum supercharging pressure or the filtered value of the minimum supercharging pressure according to the engine power performance requirements; S4. Judge whether to allow supercharging closed-loop enabling according to the minimum supercharging pressure.

[0023] In step S1, the initial value of the minimum supercharging pressure is expressed as ;

[0024] Among them, is the engine speed, is the pressure at the outlet of the mixing valve (in this embodiment, the pressure at the outlet of the EGR valve is used instead, or obtained through estimation, or detected by the installed gas pressure sensor), is the basic value of the minimum supercharging pressure; is the temperature of the gas at the outlet of the mixing valve (obtained by detection with the installed gas pressure sensor in this embodiment, or obtained through estimation), is the first minimum supercharging pressure correction coefficient, obtained according to the temperature of the gas at the outlet of the mixing valve; is the pressure of the gas at the outlet of the throttle valve, is the pressure of the gas at the inlet of the throttle valve, is the throttle pressure ratio, is the filtered value of the throttle pressure ratio, is the estimated value of the pressure of the gas at the inlet of the throttle valve, is the estimated throttle pressure ratio, is the filtered value of the estimated throttle pressure ratio, is the third minimum supercharging pressure correction coefficient, obtained according to the filtered value of the throttle pressure ratio and the filtered value of the estimated throttle pressure ratio.

[0025] Estimated value of the pressure of the gas at the inlet of the throttle valve Satisfy:

[0026] Wherein, is the estimated change in the throttle inlet gas pressure, and the change in the throttle inlet gas pressure satisfies:

[0027] Wherein, is the value at the previous sampling moment, is the estimated value of the throttle inlet gas pressure at the previous sampling moment, is the sampling period, is the time constant (the value in this embodiment is 0.05 s); in this embodiment, the initial takes a fixed value C (the value in this embodiment is 0).

[0028] Throttle pressure ratio filtering value Satisfies:

[0029] Wherein, is the first filtering time, , is the sampling time (the value in this embodiment is 10 ms), is the throttle pressure ratio filtering value of the previous sampling period (the default value in this embodiment is 1); Throttle estimated pressure ratio filtering value Satisfies:

[0030] Wherein, is the second filtering time, , is the throttle estimated pressure ratio filtering value of the previous sampling period (the default value in this embodiment is 1); In this embodiment, , the relationship between the engine speed n and or is obtained through calibration. The calibration data in this embodiment is as follows:

[0031] The above calibration basis is: the greater the engine speed, due to the engine working cycle characteristics, the faster the change in the throttle pressure ratio , the greater the first filtering time , and the throttle pressure ratio should be prevented from changing too fast to avoid the initial value of the minimum boost pressure The fluctuations are too large, which in turn leads to excessive fluctuations in the supercharging activation enable condition flag (in this embodiment, the supercharging activation enable condition flag is 0 or 1, where 0 indicates disabled and 1 indicates enabled). Therefore, during calibration in this embodiment, the calibration target is the minimum supercharging pressure initial value The fluctuation period of the supercharging activation enable condition flag caused by the change exceeds 0.06 s (that is, there is at most one transition from enabled to disabled or from disabled to enabled for the supercharging enable activation condition within 0.06 s).

[0032] Minimum supercharging pressure base value Determined according to the engine speed n and the outlet pressure of the mixing valve The calibration data in this embodiment are as follows:

[0033] In this embodiment, the first minimum supercharging pressure correction coefficient And the calibration data of the outlet gas temperature of the mixing valve Are as follows:

[0034] 、 The calibration method is: on the engine test bench, = = = =0.2 ± 0.02. It is mainly calibrated at different engine speeds, adjusting different outlet pressures of the mixing valve, and monitoring different outlet temperatures of the mixing valve. During the preset time t1 (0.2 s in this embodiment) after the supercharging control is activated, the difference between the target intake pressure of the throttle valve And the outlet pressure of the throttle valve Is within the preset range (±2 kPa in this example). At the same time, the difference between the target supercharging pressure and the actual supercharging pressure becomes smaller and smaller, and within 30% of the second half of the preset time t1 (0.2 s in this embodiment), that is, within t2 (0.06 s in this embodiment, that is, the accuracy of the difference between the target supercharging pressure and the actual supercharging pressure is not considered within the first 0.2 s - 0.06 s = 0.14 s after the supercharging control is activated because the supercharging control takes time to respond, but it is considered within the last 0.06 s) after the supercharging control is activated, the difference between the target supercharging pressure and the actual supercharging pressure is not less than ±2 kPa.

[0035] In this embodiment, the calibration method of the third minimum supercharging pressure correction coefficient Is: on the engine test bench, by adjusting = To preliminarily determine and perform final optimization under the vehicle's transient operating conditions. The intake pressure is mainly controlled by the throttle valve preferentially. The final calibration is still based on the fact that during the preset time t1 (0.2 s in this embodiment) after the boost control is activated, the target intake pressure of the throttle valve can be achieved and the pressure at the throttle valve outlet have a difference within the preset range (±2 kPa in this example). At the same time, the difference between the target boost pressure and the actual boost pressure becomes smaller and smaller. And within 30% of the latter half of the preset time t1 (0.2 s in this embodiment), that is, within t2 (0.06 s in this embodiment, that is, the accuracy of the difference between the target boost pressure and the actual boost pressure is not considered within the first 0.2 s - 0.06 s = 0.14 s after the boost control is activated because the boost control needs time to respond, but it should be considered within the subsequent 0.06 s), the difference between the target boost pressure and the actual boost pressure is not less than ±2 kPa.

[0036] In step S2, the minimum boost pressure filter value is expressed as , and it satisfies:

[0037] where is the minimum boost pressure filter value obtained in the previous sampling period, and its default value is equal to the minimum boost pressure initial value at the corresponding same moment .

[0038] is the minimum boost pressure filtering time, and its value-taking rule is as follows; 1) Continuously satisfy for a time exceeding t3 (0.1 s in this embodiment); where is the pressure at the inlet of the mixing valve, is the pressure at the inlet of the mixing valve after first-order low-pass filtering; k1 is taken as 0.1 in this embodiment; the pressure at the inlet of the mixing valve after first-order low-pass filtering in the Nth sampling period is expressed as , and it satisfies:

[0039] where is the pressure at the inlet of the mixing valve, is the pressure at the inlet of the mixing valve in the Nth sampling period, is the pressure at the inlet of the mixing valve after first-order low-pass filtering in the (N - 1)th sampling period, N = 1, 2, 3...; specifically, is equal to the pressure at the inlet of the mixing valve at the 0th sampling period , and this moment is when the vehicle is powered on; is a coefficient: (The number of cylinders of the engine in this example is 4, and the rated speed is 1000 rpm. The purpose of such setting is for normalization. Under different numbers of cylinders and speeds, there is no need for special calibration. Only the of the 4-cylinder engine and the speed of 1000 rpm need to be calibrated, thus reducing the calibration test work.), where is the number of cylinders of the engine, is the engine speed, is the filtering coefficient of the inlet pressure of the mixing valve, and in this example, it is taken as 0.05; 2) The continuous satisfaction time exceeds t4 (in this embodiment, it is taken as 0.1 s); where k2 is taken as 0.12 in this example; Among them, is the actual EGR rate, is the actual EGR rate of the Nth sampling period, is the actual EGR rate after first-order low-pass filtering, is the actual EGR rate after first-order low-pass filtering of the Nth sampling period, is the actual EGR rate after first-order low-pass filtering of the (N - 1)th sampling period, N = 1, 2, 3...; Specifically, is equal to the actual EGR rate of the 0th sampling period , and this moment is the vehicle power-on moment, The default value of is 0; The coefficient satisfies: , is the filtering coefficient of the actual EGR rate, and in this embodiment, it is taken as 0.02; In this embodiment, the number of cylinders of the engine m is 4, The rated engine speed n of is 1000 rpm. It should be understood that The purpose of the setting of is for normalization. Under different numbers of cylinders and speeds, there is no need for special calibration. Only the under the condition of a 4-cylinder engine and a speed of 1000 rpm needs to be calibrated, thus reducing the calibration test work; If any one of the conditions in 1) and 2) is satisfied, then = ; Among them is taken as 0.05 s in this embodiment; is the correction coefficient of the inlet pressure fluctuation of the mixing valve, is the correction coefficient of the actual EGR rate fluctuation; In this embodiment, the minimum supercharging pressure filtering time is forced to be limited within 0.05 - 0.15 s to avoid excessive regulation; The correction coefficient of the inlet pressure fluctuation of the mixing valve satisfies:

[0040] In this embodiment, the calibration data is as follows:

[0041] It should be understood that the purpose of increasing the filtering time is to avoid excessive fluctuations in the inlet pressure of the mixing valve, which may lead to excessive fluctuations in the minimum supercharging pressure; Actual EGR rate fluctuation correction coefficient Satisfies:

[0042]

[0043] It should be understood that the purpose of increasing the filtering time is to avoid excessive fluctuations in the EGR rate, which may lead to excessive fluctuations in the minimum supercharging pressure; If neither 1) nor 2) is satisfied, then = .

[0044] In step S3, when the engine power demand is too high, in order to quickly meet the power demand, it is necessary to quickly achieve the supercharging request. At this time, the minimum supercharging pressure is equal to the initial value of the minimum supercharging pressure , that is = ; otherwise, to better ensure the stability of supercharging control, the minimum supercharging pressure is equal to the filtered value of the minimum supercharging pressure , that is = ; In this embodiment, the conditions for excessive engine performance demand are: 1) The engine requested torque is not less than 95% of the maximum torque that the current power system can provide; 2) The throttle pedal opening is large enough, not less than 98%; 3) The throttle valve opening exceeds the preset value (in this embodiment, it is 90%); 4) The difference between the engine basic ignition angle efficiency and the actual ignition angle efficiency does not exceed the preset value (in this embodiment, it is 0.1); 5) The engine does not experience any knocking or pre-ignition.

[0045] When all of the above 1) - 5) are satisfied and continue to exceed the preset time t5 (in this embodiment, it is 0.03 s), it is considered that the engine performance demand is excessive.

[0046] In step S4, when the following conditions are simultaneously met, supercharging closed-loop enabling is allowed: 1) The minimum pressure condition for supercharging closed-loop enabling is satisfied; 2) The engine speed is greater than a preset value (600 rpm is taken in this embodiment); 3) The electronic pressure relief valve of the supercharger assembly is not opened; The judgment on whether the minimum pressure condition for supercharging closed-loop enabling is satisfied is as follows: When the difference between the target compressor outlet pressure and the minimum supercharging pressure is greater than a preset value C1 (2 kPa is taken in this embodiment), the minimum pressure condition for supercharging closed-loop enabling is satisfied, that is, the minimum pressure flag bit for supercharging closed-loop enabling is 1; When the difference between the target compressor outlet pressure and the minimum supercharging pressure is greater than a preset value C2 (-3.5 kPa is taken in this embodiment) and less than C3 (-1 kPa is taken in this embodiment), the minimum pressure condition for supercharging closed-loop enabling is not satisfied, that is, the minimum pressure flag bit for supercharging closed-loop enabling is 0; In other cases, the minimum pressure condition for supercharging closed-loop enabling maintains the previous state; specifically, when the vehicle is powered on, the minimum pressure condition for supercharging closed-loop enabling is not satisfied, that is, the minimum pressure flag bit for supercharging closed-loop enabling is 0.

[0047] After supercharging closed-loop enabling is permitted, supercharging closed-loop control is performed.

[0048] Embodiment 2: This embodiment provides a computer device, such as a smart phone, a tablet computer, a notebook computer, a desktop computer, a rack server, a blade server, a tower server or a cabinet server (including an independent server, or a server cluster composed of multiple servers) that can execute programs. The computer device of this embodiment at least includes, but is not limited to: a memory and a processor that can communicate with each other through a system bus.

[0049] In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM). The memory can also be an external storage device of the computer device, such as a plug-in hard disk equipped on the computer device, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Of course, the memory can also include both the internal storage unit of the computer device and its external storage device. In this embodiment, the memory is generally used to store the operating system installed on the computer device and various application software, such as the program code of the control method for improving the supercharging closed-loop activation condition in Embodiment 1. In addition, the memory can also be used to temporarily store various data that have been output or will be output.

[0050] In some embodiments, the processor can be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips. The processor is generally used to control the overall operation of the computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data to implement the control method for improving the supercharging closed-loop activation condition in Embodiment 1.

[0051] It should be noted that according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0052] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for improving boost closed loop activation conditions, characterized in that: include: Get the initial value of minimum boost pressure; Obtaining a minimum boost pressure filtering value according to the minimum boost pressure initial value; Determine the minimum boost pressure as a minimum boost pressure initial value or a minimum boost pressure filtering value according to the engine power performance requirement; Whether to allow boost closed loop to be enabled is determined based on the minimum boost pressure.

2. The control method for improving boost closed loop activation conditions according to claim 1, characterized in that: The minimum boost pressure initial value is obtained according to the minimum boost pressure base value, the first minimum boost pressure correction coefficient, the mixing valve outlet pressure, and the third minimum boost pressure correction coefficient; Among them, the minimum boost pressure base value is determined according to the engine speed and the mixing valve outlet pressure; The first minimum boost pressure correction coefficient is determined according to the gas temperature at the mixing valve outlet; The third minimum boost pressure correction coefficient is obtained according to the throttle pressure ratio filter value and the throttle estimated pressure ratio filter value; the throttle pressure ratio filter value is obtained by filtering the throttle pressure ratio, and the throttle estimated pressure ratio filter value is obtained by filtering the throttle estimated pressure ratio, the throttle pressure ratio is the ratio of the throttle outlet gas pressure to the throttle inlet gas pressure, and the throttle estimated pressure ratio is the ratio of the throttle outlet gas pressure to the estimated throttle inlet gas pressure.

3. The control method for improving the boost closed loop activation condition according to claim 2, characterized in that: The relationship between the minimum boost pressure base value and the engine speed and the mixing valve outlet pressure is determined through calibration; The relationship between the first minimum boost pressure correction coefficient and the gas temperature at the mixing valve outlet is determined by calibration; The relationship between the third minimum boost pressure correction coefficient, the throttle pressure ratio filter value, and the throttle estimated pressure ratio filter value is determined through calibration.

4. The control method for improving boost closed loop activation conditions according to claim 2, characterized in that: The estimated value of the throttle inlet gas pressure is obtained according to the throttle inlet gas pressure and the estimated throttle inlet gas pressure change; The estimated throttle inlet gas pressure change is determined by the throttle inlet gas pressure estimated value at different sampling periods, the sampling period, and the time constant.

5. The control method for improving boost closed loop activation conditions according to claim 2, characterized in that: The method for obtaining the throttle pressure ratio filter value includes: Obtaining a throttle pressure ratio filtering value according to the throttle pressure ratio, the throttle pressure ratio filtering value of the previous sampling period, the sampling time, and the first filtering time; The first filtering time is obtained according to the engine speed; The method for obtaining the throttle estimated pressure ratio filter value includes: Obtaining a throttle pressure ratio filtering value according to the throttle estimated pressure ratio, the throttle estimated pressure ratio filtering value of the previous sampling period, the sampling time, and the second filtering time; The second filtering time is obtained according to the engine speed.

6. The control method for improving boost closed loop activation conditions according to claim 1, characterized in that: The method for obtaining the minimum boost pressure filtering value includes: The minimum boost pressure filtering value is obtained according to the minimum boost pressure initial value, the minimum boost pressure filtering value of the previous sampling period, the sampling time, and the minimum boost pressure filtering time.

7. The control method for improving boost closed loop activation conditions according to claim 1, characterized in that: The minimum boost pressure filter time is obtained as follows: Determine a first parameter according to the mixing valve inlet pressure and the mixing valve inlet pressure after first-order low-pass filtering; Determine a second parameter according to the actual EGR rate and the actual EGR rate after first-order low-pass filtering; When the first parameter exceeds the preset value and lasts for a certain period of time, or when the second parameter exceeds the preset value and lasts for a certain period of time, the minimum boost pressure filtering time is determined according to the mixing valve inlet pressure fluctuation correction coefficient and the actual EGR rate fluctuation correction coefficient; otherwise, the minimum boost pressure filtering time takes the preset value; Furthermore, the minimum boost pressure filtering time is limited to a preset interval; The mixing valve inlet pressure fluctuation correction coefficient is determined according to the first parameter; the actual EGR rate fluctuation correction coefficient is determined according to the second parameter.

8. The control method for improving boost closed loop activation conditions according to claim 1, characterized in that: The method for determining the minimum boost pressure as the minimum boost pressure initial value or the minimum boost pressure filtered value according to the engine power performance requirement comprises: When the engine power demand is too large, the minimum boost pressure is made equal to the minimum boost pressure initial value; otherwise, the minimum boost pressure is made equal to the minimum boost pressure filtered value; Methods for determining whether the engine power demand is too large include: 1) The engine request torque is not less than a certain percentage of the maximum torque that the current power system can provide; 2) The accelerator pedal opening is greater than or equal to a certain percentage; 3) The throttle opening exceeds a certain percentage; 4) The difference between the basic ignition angle efficiency and the actual ignition angle efficiency of the engine does not exceed the preset value; 5) The engine does not experience any knock and pre-ignition; When the above 1) to 5) are all met and continue for more than the preset time, it is considered that the engine power demand is too large.

9. The control method for improving boost closed loop activation conditions according to claim 1, characterized in that: The method for determining whether to allow boost closed loop enabling according to the minimum boost pressure includes: When the following conditions are met at the same time, the boost closed loop is enabled: 1) The minimum pressure condition for boost closed loop enabling is met; 2) The engine speed is greater than the preset value; 3) The electronic pressure relief valve of the supercharger assembly is not opened; Among them, the method for judging whether the minimum pressure condition for enabling the boost closed loop is met includes: When the difference between the target compressor outlet pressure and the minimum boost pressure is greater than the preset value, the boost closed loop enabling minimum pressure condition is met; When the difference between the target compressor outlet pressure and the minimum boost pressure is within the preset interval, the minimum pressure condition for enabling the boost closed loop is not met; In other cases, the minimum pressure condition for enabling the boost closed loop remains in the previous state; and, when the vehicle is powered on, the minimum pressure condition for enabling the boost closed loop is not met.

10. 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, the steps of the control method for improving the boost closed-loop activation condition as described in any one of claims 1 to 9 are implemented.

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