A method and apparatus for determining supercharging pressure, a storage medium and an equipment

Abstract

The application discloses a method and device for determining supercharging pressure, a storage medium and equipment. Through the technical scheme provided by the embodiment of the application, the concepts of target exhaust back pressure and target exhaust flow rate are introduced into the supercharging control logic, the decoupling with the actual exhaust back pressure and the actual VGT opening degree can be realized, and the supercharging control overshoot caused by coupling can be avoided. Meanwhile, the target exhaust back pressure and the target exhaust flow rate are used for calculation, the VGT can be effectively prevented from being in a large degree of closed state for a long time under a dynamic working condition (Tip-In), the exhaust back pressure can be prevented from rising too fast and too high, the quick establishment of the charging efficiency is helped, and thus the drivability of the vehicle is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vehicles, and particularly relates to a method and device for determining supercharging pressure, a storage medium and equipment. BACKGROUND

[0002] With the rapid development of the automobile and internal combustion engine industries, energy demand and environmental protection have become difficult problems faced by countries in the world, and therefore energy saving and emission reduction have become two major themes in the development of the internal combustion engine industry. At present, in order to further improve the fuel economy of traditional gasoline engines, Miller cycle technology is widely used in new generation engines by automobile manufacturers at home and abroad. Miller cycle can effectively reduce the pumping loss at medium and small loads by early closing of the intake valve, and can reduce the effective compression ratio of the engine by early closing of the intake valve, so that the engine applying the Miller cycle can realize a higher geometric compression ratio and thus improve the combustion efficiency of the engine.

[0003] Although the Miller cycle engine has high fuel economy, its power performance at low speed and high load (Low End Torque) directly depends on the performance of the turbocharger. In order to improve this problem, in recent years, the VGT (Variable Geometry Turbocharger) variable cross-section turbocharging technology has been increasingly applied to Miller cycle gasoline engines.

[0004] Practice shows that the VGT system can cause a sharp change in exhaust back pressure during dynamic supercharging; especially in the Miller cycle engine, due to the significant increase in the large overlap angle working condition interval, the calculation of residual exhaust gas is affected by the exhaust back pressure, which further affects the charging efficiency; because the actual exhaust pressure and the actual exhaust flow used in the current supercharging control logic are coupled, it is easy to cause overshoot in the establishment process of dynamic charging efficiency and affect the performance of the mixture. In addition, using the actual exhaust pressure and the actual exhaust flow for calculation can also cause the VGT to be in a large degree of closing state (near the minimum cross-sectional area) for a long time under dynamic working conditions (Tip-In), and thus cause the exhaust back pressure to increase more sharply; but if the exhaust back pressure rises too fast and too high, it is easy to cause the residual exhaust gas partial pressure to be too high, which is not conducive to the rapid establishment of the charging efficiency and affects the drivability of the vehicle under the same intake pressure change rate. SUMMARY

[0005] The present application discloses a method and device for determining supercharging pressure, a storage medium and equipment, which can improve the drivability of a vehicle.

[0006] In one aspect, the embodiments of the present application provide a method for determining a boost pressure, comprising:

[0007] determining a target intake flow of the engine based on a required charge efficiency of the engine;

[0008] determining a target exhaust flow of the engine based on the target intake flow and an air-fuel ratio;

[0009] determining a target opening of a variable area turbine of the engine based on the target exhaust flow and a reference boost pressure, the reference boost pressure being a target boost pressure determined in a previous round of calculation;

[0010] determining a target exhaust back pressure of the engine based on the target exhaust flow and the target opening;

[0011] determining a current target boost pressure of the engine based on the target exhaust back pressure and the required charge efficiency.

[0012] In one possible implementation, the determining of the target intake flow of the engine based on the required charge efficiency of the engine comprises:

[0013] multiplying the required charge efficiency by a first conversion coefficient to obtain the target intake flow of the engine, the first conversion coefficient being associated with a rotational speed of the engine.

[0014] In one possible implementation, the determining of the target exhaust flow of the engine based on the target intake flow and the air-fuel ratio comprises:

[0015] adding the air-fuel ratio to a first numerical value to obtain a second conversion coefficient, the air-fuel ratio being associated with an excess air coefficient and an air-fuel ratio;

[0016] multiplying the target intake flow by the second conversion coefficient to obtain the target exhaust flow of the engine.

[0017] In one possible implementation, the determining of the target opening of the variable area turbine of the engine based on the target exhaust flow and the reference boost pressure comprises:

[0018] determining an adiabatic compression work of a compressor of the engine based on the reference boost pressure, a required flow at a rear end of the compressor, a temperature at a front end of the compressor, an efficiency of the compressor, an intake specific heat capacity of the compressor, a front pressure of the compressor, and an ideal gas adiabatic index;

[0019] determining a required power of the variable area turbine of the compressor based on the adiabatic compression work;

[0020] determining a target turbine expansion ratio of the variable area turbine based on the target exhaust gas flow rate, a front end temperature of the variable area turbine, an efficiency of the variable area turbine, a specific heat capacity of exhaust gas, and an ideal gas adiabatic index of exhaust gas, the target turbine expansion ratio being a ratio of a back pressure to a front pressure of the variable area turbine;

[0021] determining a target opening of the variable area turbine based on the target exhaust gas flow rate, the target turbine expansion ratio, an effective cross-sectional area of the variable area turbine, and a flow correction coefficient.

[0022] In one possible implementation, the determining the target exhaust back pressure of the engine based on the target exhaust gas flow rate and the target opening includes:

[0023] applying the target exhaust gas flow rate and the target opening into a valve port flow equation to obtain the target exhaust back pressure.

[0024] In one possible implementation, the determining the target boost pressure of the engine based on the target exhaust back pressure and the required charge efficiency includes:

[0025] determining a target residual exhaust gas partial pressure in a cylinder of the engine based on the target exhaust back pressure and a reference boost pressure;

[0026] determining the target boost pressure based on the target residual exhaust gas partial pressure and a charge partial pressure corresponding to the required charge efficiency.

[0027] In one possible implementation, the determining the target boost pressure based on the target residual exhaust gas partial pressure and the charge partial pressure corresponding to the required charge efficiency includes:

[0028] applying the target residual exhaust gas partial pressure and the charge partial pressure corresponding to the required charge efficiency into an ideal gas equation to obtain the target boost pressure.

[0029] In one possible implementation, after the determining the target boost pressure of the engine based on the target exhaust back pressure and the required charge efficiency, the method further includes:

[0030] adjusting an opening of a variable area turbine of the engine based on the target boost pressure and the target exhaust gas flow rate.

[0031] In one aspect, an embodiment of the present application provides a determination device of a boost pressure, and the method includes:

[0032] a target intake amount determination module configured to determine a target intake flow rate of the engine based on a required charge efficiency of the engine;

[0033] a target exhaust flow determination module configured to determine a target exhaust flow of the engine based on the target intake flow and an air-fuel ratio;

[0034] a target opening determination module configured to determine a target opening of a variable area turbine of the engine based on the target exhaust flow and a reference boost pressure, the reference boost pressure being a target boost pressure determined in a previous round of calculation;

[0035] a target exhaust back pressure determination module configured to determine a target exhaust back pressure of the engine based on the target exhaust flow and the target opening;

[0036] a target boost pressure determination module configured to determine a target boost pressure of the engine based on the target exhaust back pressure and the required charge efficiency.

[0037] In a possible implementation, the target intake flow determination module is configured to multiply the required charge efficiency by a first conversion coefficient associated with a rotational speed of the engine to obtain the target intake flow of the engine.

[0038] In a possible implementation, the target exhaust flow determination module is configured to add the air-fuel ratio to a first numerical value to obtain a second conversion coefficient, the air-fuel ratio being related to an excess air coefficient and an air-fuel ratio; and multiply the target intake flow by the second conversion coefficient to obtain the target exhaust flow of the engine.

[0039] In a possible implementation, the target opening determination module is configured to determine an adiabatic compression work of a compressor of the engine based on the reference boost pressure, a required flow at a back end of the compressor, a temperature at a front end of the compressor, an efficiency of the compressor, an intake specific heat capacity of the compressor, a front pressure of the compressor, and an ideal gas adiabatic index; determine a required power of a variable area turbine of the compressor based on the adiabatic compression work; determine a target turbine expansion ratio of the variable area turbine based on the target exhaust flow, a temperature at a front end of the variable area turbine, an efficiency of the variable area turbine, an exhaust specific heat capacity, and an ideal gas adiabatic index of exhaust gas, the target turbine expansion ratio being a ratio of a back pressure to a front pressure of the variable area turbine; and determine the target opening of the variable area turbine based on the target exhaust flow, the target turbine expansion ratio, an effective cross-sectional area of the variable area turbine, and a flow correction coefficient.

[0040] In a possible implementation, the target exhaust back pressure determination module is configured to bring the target exhaust flow and the target opening into a valve port flow equation to obtain the target exhaust back pressure.

[0041] In a possible implementation, the target supercharging pressure determination module is configured to determine a target residual exhaust gas partial pressure in the cylinder of the engine based on the target exhaust back pressure and the reference supercharging pressure; and determine the target supercharging pressure based on the target residual exhaust gas partial pressure and an intake gas partial pressure corresponding to the required intake efficiency.

[0042] In a possible implementation, the target supercharging pressure determination module is configured to bring the target residual exhaust gas partial pressure and the intake gas partial pressure corresponding to the required intake efficiency into an ideal gas equation to obtain the target supercharging pressure.

[0043] In a possible implementation, the device further includes:

[0044] The adjustment module is configured to adjust an opening degree of a variable cross-section turbine of the engine based on the target supercharging pressure and the target exhaust flow.

[0045] In an aspect, an electronic device is provided, and the electronic device includes:

[0046] at least one processor and a memory connected with the at least one processor in communication; and wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method for determining the supercharging pressure.

[0047] In an aspect, a non-transitory computer-readable storage medium stores computer instructions for causing a computer to perform the method for determining the supercharging pressure.

[0048] In an aspect, an embodiment of the present application further provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, and the program instructions, when executed by a computer, cause the computer to perform the method for determining the supercharging pressure.

[0049] Through the technical solutions provided by the embodiments of the present application, by introducing the concepts of target exhaust back pressure and target exhaust flow into the supercharging control logic, decoupling from the actual exhaust back pressure and the actual VGT opening degree can be achieved, and supercharging control overshoot caused by coupling can be avoided; at the same time, using the target exhaust back pressure and the target exhaust flow for calculation can also effectively reduce the long-time closing of the VGT at a large degree under a dynamic working condition (Tip-In), avoid the rapid and high rise of the exhaust back pressure, help the rapid establishment of the intake efficiency, and thus improve the drivability of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the present application, and to facilitate further understanding of the technical effects, technical features and purposes of the present application, the present application will be described in detail below with reference to the drawings, which constitute an integral part of the specification, and together with the embodiments of the present application, serve to illustrate the technical solutions of the present application, but do not constitute a limitation on the present application.

[0051] Figure 1 A schematic diagram of an implementation environment provided for the embodiments of the present application is shown in the figure;

[0052] Figure 2 A flowchart of a method for determining supercharged pressure provided for the embodiments of the present application is shown in the figure;

[0053] Figure 3 A flowchart of another method for determining supercharged pressure provided for the embodiments of the present application is shown in the figure;

[0054] Figure 4 A flowchart of still another method for determining supercharged pressure provided for the embodiments of the present application is shown in the figure;

[0055] Figure 5 A structural schematic diagram of a device for determining supercharged pressure provided for the embodiments of the present application is shown in the figure;

[0056] Figure 6 A structural schematic diagram of an electronic device provided for the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0057] The implementation manners of the present application are described below through specific and concrete examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. The present application can also be implemented or applied through other different specific implementation manners, and each item of detail in the present specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor, fall within the scope of protection of the present application.

[0058] It is to be understood that the embodiments described herein are illustrative only and the scope of the application should not be deemed limited thereto based on their description in the attached claims. Various modifications can be made that remain within the scope of the embodiments as described herein. It will be apparent to those skilled in the art that substantial equivalents can be prepared without departing from the scope of the embodiments described herein. Thus, the disclosed embodiments are not intended to limit the scope of the application but rather the true scope of the embodiments described herein is measured by the appended claims.

[0059] It is also to be understood that the following description is only illustrative of the application and is not intended to limit the scope of the application as defined by the appended claims. Various modifications can be made that remain within the scope of the embodiments as described herein. It will be apparent to those skilled in the art that substantial equivalents can be prepared without departing from the scope of the embodiments described herein. Thus, the disclosed embodiments are not intended to limit the scope of the application but rather the true scope of the embodiments described herein is measured by the appended claims.

[0060] In addition, in the following description, specific details are provided to thoroughly understand the examples. However, one of ordinary skill in the art will understand that the aspects can be practiced without these specific details.

[0061] Figure 1 is a schematic diagram of an implementation environment of the method for determining supercharging pressure provided by the embodiments of the application, referring to Figure 1 The implementation environment includes a vehicle terminal 110 and an engine controller 140.

[0062] The vehicle terminal 110 is connected to the engine controller 140 through a wireless network. The vehicle terminal 110 runs a target application program, which can control the engine controller 140. The target application program is a control application program of a hybrid vehicle. In some embodiments, the vehicle terminal 110 is connected to the engine controller 140 in a wired or wireless manner.

[0063] The engine controller 140 is used to control the engine, such as starting, stopping, adjusting the engine throttle, and changing the engine speed.

[0064] After introducing the implementation environment of the embodiments of the application, the application scenarios of the embodiments of the application are described below.

[0065] The method for determining supercharging pressure provided by the embodiments of the application can be applied to scenarios of determining the target supercharging pressure of engines of various vehicles.

[0066] After introducing the implementation environment and the application scenarios of the embodiments of the application, the method for determining supercharging pressure provided by the embodiments of the application is described below, referring to Figure 2For example, taking the electronic device as the execution subject, the method comprises:

[0067] 201. The vehicle terminal determines the target intake flow of the engine based on the demand volumetric efficiency of the engine.

[0068] The volumetric efficiency refers to the ratio of the mass of air inhaled in each intake stroke to the mass of dry air occupying the piston stroke volume of the cylinder under standard conditions (1 atmosphere, 20°C, density 1.187 kg / m2). When the atmospheric pressure is high, the temperature is low, and the density is high, the volumetric efficiency of the engine will also increase. The volumetric efficiency is the ratio of the actual fresh charge entering the cylinder to the fresh charge filling the cylinder under intake conditions. It is also called the impulse coefficient of the engine.

[0069] 202. The vehicle terminal determines the target exhaust flow of the engine based on the target intake flow and the air-fuel ratio.

[0070] The air-fuel ratio is associated with the excess air coefficient and the air-fuel ratio. The excess air coefficient refers to the ratio of the actual air mass supplied for burning one kilogram of fuel to the theoretical air mass required for completely burning one kilogram of fuel. The air-fuel ratio is the mass ratio between air and fuel in the mixture. It is generally expressed in grams of air consumed per gram of fuel burned.

[0071] 203. The vehicle terminal determines the target opening of the variable cross-section turbine of the engine based on the target exhaust flow and the reference boost pressure, which is the target boost pressure determined in the last round of calculation.

[0072] The variable cross-section turbine is a device for turbocharging, and the gasoline engine of the variable cross-section turbocharger. The heart of the turbocharging system is the adjustable cross-section guide vane. These guide vanes can be closed under low speed and low exhaust conditions, thereby increasing the intake pressure of the engine.

[0073] 204. The vehicle terminal determines the target exhaust back pressure of the engine based on the target exhaust flow and the target opening.

[0074] The exhaust back pressure refers to the resistance pressure of the engine exhaust. When the exhaust back pressure rises, the engine exhaust is not smooth, thereby affecting the power of the engine. The exhaust back pressure has a very large impact on the overall performance of the engine. Generally, an increase in exhaust back pressure directly leads to an increase in engine fuel consumption rate and deterioration of engine economic performance. At the same time, the engine power also deteriorates, and the exhaust emission quality also deteriorates due to insufficient combustion in the cylinder.

[0075] 205、The vehicle terminal determines the target supercharging pressure of the engine based on the target exhaust back pressure and the required volumetric efficiency.

[0076] The target supercharging pressure is used to control the opening of the variable cross-section turbine of the engine.

[0077] By introducing the concepts of target exhaust back pressure and target exhaust flow in the supercharging control logic, the decoupling of the actual exhaust back pressure and the actual VGT opening can be achieved, and the supercharging control overshoot caused by coupling can be avoided. At the same time, using the target exhaust back pressure and the target exhaust flow for calculation can also effectively reduce the long-term closing of the VGT under dynamic conditions (Tip-In), avoid the rapid and high rise of the exhaust back pressure, help the rapid establishment of the charging efficiency, and thus improve the drivability of the vehicle.

[0078] The above steps 201-205 are a simple description of the determination method of the supercharging pressure provided by the embodiments of the present application. The determination method of the supercharging pressure provided by the embodiments of the present application will be described in detail below in combination with some examples, see Figure 3 The method comprises:

[0079] 301、The vehicle terminal determines the target intake flow of the engine based on the required volumetric efficiency of the engine.

[0080] The volumetric efficiency refers to the ratio of the mass of air inhaled per intake stroke to the mass of dry air occupying the piston stroke volume under standard conditions (1 atmosphere, 30°C, density 1.187 kg / m2). When the atmospheric pressure is high, the temperature is low, and the density is high, the volumetric efficiency of the engine will also increase. The volumetric efficiency is the ratio of the fresh charge actually entering the cylinder to the fresh charge filling the cylinder under the intake state. It is also called the impulse coefficient of the engine.

[0081] In a possible implementation, the vehicle terminal multiplies the required volumetric efficiency by a first conversion coefficient to obtain the target intake flow of the engine, and the first conversion coefficient is associated with the speed of the engine.

[0082] For example, the vehicle terminal multiplies the required volumetric efficiency by a first conversion coefficient to obtain the target intake flow of the engine by the following formula (1).

[0083]

[0084] Wherein, is the target intake flow, rl des is the required volumetric efficiency, For the first conversion coefficient, the first conversion coefficient is associated with the rotational speed n Eng and the related charge efficiency.

[0085] 302、The vehicle terminal determines the target exhaust flow of the engine based on the target intake flow and the air-fuel coefficient.

[0086] The air-fuel coefficient is associated with the excess air coefficient and the air-fuel ratio. The excess air coefficient refers to the ratio of the actual air mass supplied for burning one kilogram of fuel to the theoretical air mass required for completely burning one kilogram of fuel. The air-fuel ratio refers to the mass ratio between air and fuel in the mixture. Generally, it is expressed by the number of grams of air consumed per gram of fuel burned.

[0087] In one possible implementation, the vehicle terminal adds the air-fuel coefficient, which is associated with the excess air coefficient and the air-fuel ratio, to a first numerical value to obtain a second conversion coefficient. The vehicle terminal multiplies the target intake flow and the second conversion coefficient to obtain the target exhaust flow of the engine.

[0088] For example, the vehicle terminal obtains the target exhaust flow of the engine through the following formula (2).

[0089]

[0090] wherein, is the target exhaust flow, k air / fuel is the air-fuel coefficient, which is directly associated with the excess air coefficient and the air-fuel ratio.

[0091] 303、The vehicle terminal determines the target opening of the variable cross-section turbine of the engine based on the target exhaust flow and a reference boost pressure, which is the target boost pressure determined in the last round of calculation.

[0092] The variable cross-section turbine is a device for turbocharging, a gasoline engine with a variable cross-section turbocharger. The heart of the turbocharging system is the adjustable cross-section guide vane. These guide vanes can be closed in the low-speed, low-exhaust-flow working condition, thereby increasing the intake pressure of the engine.

[0093] In a possible implementation, the vehicle terminal determines the adiabatic compression work of the compressor based on the reference boost pressure, the rear-end required flow of the compressor of the engine, the front-end temperature of the compressor, the efficiency of the compressor, the specific heat capacity of the intake air of the compressor, the front pressure of the compressor, and the ideal gas adiabatic index. The vehicle terminal determines the required power of the variable cross-section turbine of the compressor based on the adiabatic compression work. The vehicle terminal determines the target turbine expansion ratio of the variable cross-section turbine based on the target exhaust flow, the front-end temperature of the variable cross-section turbine, the efficiency of the variable cross-section turbine, the specific heat capacity of the exhaust gas, and the ideal gas adiabatic index, where the target turbine expansion ratio is the ratio of the rear pressure to the front pressure of the variable cross-section turbine. The vehicle terminal determines the target opening of the variable cross-section turbine based on the target exhaust flow, the target turbine expansion ratio, the effective cross-sectional area of the variable cross-section turbine, and the flow correction coefficient.

[0094] In order to make the above-mentioned implementation clearer, the following will be divided into several parts to explain the above-mentioned implementation.

[0095] The first part, the vehicle terminal determines the adiabatic compression work of the compressor based on the reference boost pressure, the rear-end required flow of the compressor of the engine, the front-end temperature of the compressor, the efficiency of the compressor, the specific heat capacity of the intake air of the compressor, the front pressure of the compressor, and the ideal gas adiabatic index.

[0096] In a possible implementation, the vehicle terminal determines the adiabatic compression work of the compressor by the following formula (3).

[0097]

[0098] wherein, is the adiabatic compression work, is the rear-end required flow of the compressor of the engine, which is determined based on the required charge efficiency, T1 is the front-end temperature of the compressor, η cmpr is the efficiency of the compressor; c p，cmpr is the specific heat capacity of the intake air, is the reference boost pressure, p1 is the front pressure of the compressor, and k is the ideal gas adiabatic index of the intake air.

[0099] The second part, the vehicle terminal determines the required power of the variable cross-section turbine of the compressor based on the adiabatic compression work.

[0100] In a possible implementation, if the influence of friction is not considered, the turbine expansion and the compressor compression process of the turbine and the compressor on the same shaft satisfy the energy balance principle, and the required power at the turbine end can be obtained. For example, the vehicle terminal determines the required power of the variable cross-section turbine by the following formula (4).

[0101]

[0102] wherein, is the required power of the variable cross-section turbine.

[0103] The third part, the vehicle terminal determines the target turbine expansion ratio of the variable cross-section turbine based on the target exhaust flow rate, the front end temperature of the variable cross-section turbine, the efficiency of the variable cross-section turbine, the specific heat capacity of exhaust gas, and the ideal gas adiabatic index of exhaust gas.

[0104] In a possible implementation, the vehicle terminal determines the target turbine expansion ratio of the variable cross-section turbine by the following formula (5).

[0105]

[0106] wherein, T3 is the front end temperature of the variable cross-section turbine (turbine), η trb is the efficiency of the variable cross-section turbine, c p，exh is the specific heat capacity of exhaust gas, is the target turbine expansion ratio, p4 is the turbine rear pressure, p3 is the turbine front pressure, i.e. exhaust back pressure, κ exh is the ideal gas adiabatic index of exhaust gas.

[0107] The fourth part, the vehicle terminal determines the target opening of the variable cross-section turbine based on the target exhaust flow rate, the target turbine expansion ratio, the effective cross-sectional area of the variable cross-section turbine, and the flow correction coefficient.

[0108] In a possible implementation, the target turbine end expansion ratio is obtained, i.e. the effective cross-sectional area requirement of the turbine end and the target opening of the VGT nozzle ring are calculated, and the principle is to obtain the turbine equivalent effective cross-sectional area (Throttle Equation) according to Bernoulli equation and turbine adiabatic expansion theory. For example, the vehicle terminal determines the target turbine expansion ratio of the variable cross-section turbine by the following formula (6).

[0109]

[0110] wherein, A vgt is the effective cross-sectional area of the turbine end, pos vgt is the target opening of the variable cross-section turbine, i.e. the target opening of the VGT nozzle ring, ψ trb is the flow correction coefficient based on pressure ratio.

[0111] 304、The vehicle terminal determines the target exhaust back pressure of the engine based on the target exhaust flow rate and the target opening.

[0112] Wherein, the exhaust back pressure refers to the resistance pressure of the engine exhaust. When the exhaust back pressure rises, the engine exhaust is not smooth, thereby affecting the power of the engine. The exhaust back pressure has a very great influence on the comprehensive performance of the engine. Generally, the increase of the exhaust back pressure directly leads to the increase of the engine fuel consumption rate, the deterioration of the engine economic performance, the deterioration of the engine power, and the deterioration of the exhaust emission quality due to the insufficient combustion in the cylinder.

[0113] In a possible implementation, the vehicle terminal brings the target exhaust flow and the target opening into a valve port flow equation to obtain the target exhaust back pressure. In some embodiments, the valve port flow equation is formula (6) described above.

[0114] 305、The vehicle terminal determines the target supercharging pressure of the engine at present based on the target exhaust back pressure and the demand charge efficiency.

[0115] In a possible implementation, the vehicle terminal determines the target residual exhaust gas partial pressure in the cylinder of the engine based on the target exhaust back pressure and the reference supercharging pressure. The vehicle terminal determines the target supercharging pressure based on the target residual exhaust gas partial pressure and the charge partial pressure corresponding to the demand charge efficiency.

[0116] In order to make the above implementation clearer, the following will be divided into several parts to explain the above implementation.

[0117] The first part is that the vehicle terminal determines the target residual exhaust gas partial pressure in the cylinder of the engine based on the target exhaust back pressure and the reference supercharging pressure.

[0118] In a possible implementation, the target supercharging pressure is updated (current calculation process) according to the target exhaust back pressure and the demand charge efficiency. The specific calculation process is that the residual exhaust gas partial pressure in the cylinder is obtained based on the target exhaust back pressure and the target supercharging pressure obtained in the last calculation process (note that the manifold pressure is equal to the target supercharging pressure in this process because the throttle valve is fully opened). For example, the vehicle terminal determines the target residual exhaust gas partial pressure in the cylinder of the engine by formula (7) as follows.

[0119]

[0120] Wherein, is the target residual exhaust gas partial pressure, is the target residual exhaust gas relative charge in the cylinder, which is related to the target VVT position, the target exhaust back pressure and the target supercharging pressure, is the target residual exhaust gas temperature in the cylinder, which is also related to the target VVT position, the target exhaust back pressure and the target supercharging pressure, fac chrg is the target charge slope, which is related to the intake VVT closing time and the intake temperature, tIntkAir for the intake air temperature, for the target exhaust back pressure.

[0121] The second part, the vehicle terminal, determines the target boost pressure based on the target residual exhaust partial pressure and the charge air partial pressure corresponding to the demand charge efficiency.

[0122] In a possible implementation, after obtaining the target residual exhaust partial pressure in the cylinder, the target boost pressure can be calculated based on the ideal gas equation according to the target residual exhaust partial pressure and the charge air partial pressure corresponding to the current demand charge efficiency, with the gas in the cylinder as the object. That is, the vehicle terminal brings the target residual exhaust partial pressure and the charge air partial pressure corresponding to the demand charge efficiency into the ideal gas equation to obtain the target boost pressure.

[0123] For example, the vehicle terminal determines the target boost pressure by the following formula (8).

[0124]

[0125] 306、The vehicle terminal adjusts the opening of the variable cross-section turbine of the engine based on the target boost pressure and the target exhaust flow.

[0126] In a possible implementation, the vehicle terminal uses the target boost pressure and the target exhaust flow to control the opening of the variable cross-section turbine by combining the pre-control opening with the PID method.

[0127] Referring to Figure 4 After the vehicle terminal determines the target boost pressure and the target exhaust flow based on the demand charge efficiency, the vehicle terminal uses the target boost pressure and the target exhaust flow to perform boost control pre-control and uses the target boost pressure to perform boost control PID correction (proportional-integral-derivative control), where the target boost pressure is determined based on the demand corresponding to the charge efficiency, and the process of determining the target boost pressure and the target exhaust flow is assisted by the target exhaust back pressure. The vehicle terminal determines the VGT pre-control opening based on the above boost control pre-control, performs VGT target opening correction based on the above boost control PID correction, and determines the VGT duty cycle by combining the two methods, thereby controlling the opening of the VGT. In the control process, the actual opening of the VGT is obtained in real time, and the actual opening is used for adjustment.

[0128] Compared with the existing supercharging control logic, the technical scheme provided by the embodiment of the application introduces the calculation of the target exhaust flow and the target exhaust back pressure based on the demand charging efficiency. In the optimized supercharging control logic, the calculation of the target supercharging pressure is no longer based on the actual exhaust back pressure, but based on the target exhaust back pressure. At the same time, in the supercharging control pre-control logic, the target exhaust flow replaces the actual exhaust flow. The target supercharging pressure and the target exhaust flow obtained by the above method are further applied to the existing supercharging control pre-control and supercharging control PID correction logic. By introducing the concepts of the target exhaust back pressure and the target exhaust flow in the control logic, the decoupling of the actual exhaust back pressure and the actual VGT opening degree is realized.

[0129] By introducing the concepts of the target exhaust back pressure and the target exhaust flow in the supercharging control logic, the decoupling of the actual exhaust back pressure and the actual VGT opening degree is realized, and the overshoot of the supercharging control caused by coupling is avoided. At the same time, using the target exhaust back pressure and the target exhaust flow for calculation can also effectively reduce the long-time closing of the VGT in a large degree under a dynamic working condition (Tip-In), avoid the rapid and high rise of the exhaust back pressure, help the rapid establishment of the charging efficiency, and thus improve the drivability of the vehicle. In addition, since the control method is based on the optimization of the existing supercharging control logic, the additional calibration workload can be greatly reduced by reusing the existing calibration data of the system.

[0130] Corresponding to the above method embodiment, referring to Figure 5 The embodiment of the application also provides a supercharging pressure determination device 500, which comprises a target intake amount determination module 501, a target exhaust flow determination module 502, a target opening degree determination module 503, a target exhaust back pressure determination module 504, and a target supercharging pressure determination module 505.

[0131] The target intake amount determination module 501 is configured to determine the target intake flow of the engine based on the demand charging efficiency of the engine.

[0132] The target exhaust flow determination module 502 is configured to determine the target exhaust flow of the engine based on the target intake flow and the air-fuel ratio.

[0133] The target opening degree determination module 503 is configured to determine the target opening degree of the variable cross-section turbine of the engine based on the target exhaust flow and a reference supercharging pressure, the reference supercharging pressure being the target supercharging pressure determined in the last round of calculation process.

[0134] The target exhaust back pressure determination module 504 is configured to determine the target exhaust back pressure of the engine based on the target exhaust flow and the target opening degree.

[0135] The target boost pressure determination module 505 is configured to determine a target boost pressure of the engine based on the target exhaust back pressure and the required charge efficiency.

[0136] In a possible implementation, the target intake flow determination module 501 is configured to multiply the required charge efficiency by a first conversion coefficient to obtain the target intake flow of the engine, the first conversion coefficient being associated with a rotational speed of the engine.

[0137] In a possible implementation, the target exhaust flow determination module 502 is configured to add an air-fuel coefficient to a first value to obtain a second conversion coefficient, the air-fuel coefficient being associated with an excess air coefficient and an air-fuel ratio. The target intake flow is multiplied by the second conversion coefficient to obtain the target exhaust flow of the engine.

[0138] In a possible implementation, the target opening determination module 503 is configured to determine an adiabatic compression work of a compressor of the engine based on the reference boost pressure, a required flow at a back end of the compressor, a temperature at a front end of the compressor, an efficiency of the compressor, an intake specific heat capacity of the compressor, a front pressure of the compressor, and an ideal gas adiabatic index. A required power of a variable area turbine of the compressor is determined based on the adiabatic compression work. A target turbine expansion ratio of the variable area turbine is determined based on the target exhaust flow, a temperature at a front end of the variable area turbine, an efficiency of the variable area turbine, an exhaust specific heat capacity, and an ideal gas adiabatic index of the exhaust, the target turbine expansion ratio being a ratio of a back pressure to a front pressure of the variable area turbine. The target opening of the variable area turbine is determined based on the target exhaust flow, the target turbine expansion ratio, an effective cross-sectional area of the variable area turbine, and a flow correction coefficient.

[0139] In a possible implementation, the target exhaust back pressure determination module 504 is configured to input the target exhaust flow and the target opening into a valve flow equation to obtain the target exhaust back pressure.

[0140] In a possible implementation, the target boost pressure determination module 505 is configured to determine a target residual exhaust gas partial pressure in a cylinder of the engine based on the target exhaust back pressure and the reference boost pressure. The target boost pressure is determined based on the target residual exhaust gas partial pressure and a charge gas partial pressure corresponding to the required charge efficiency.

[0141] In a possible implementation, the target boost pressure determination module 505 is configured to input the target residual exhaust gas partial pressure and the charge gas partial pressure corresponding to the required charge efficiency into an ideal gas equation to obtain the target boost pressure.

[0142] In a possible implementation, the apparatus further includes:

[0143] An adjustment module is configured to adjust an opening degree of a variable cross-section turbine of the engine based on the target boost pressure and the target exhaust flow rate.

[0144] By introducing the concepts of target exhaust back pressure and target exhaust flow rate in the boost control logic, the decoupling from the actual exhaust back pressure and the actual VGT opening degree can be achieved, and the boost control overshoot caused by the coupling can be avoided. Meanwhile, the use of the target exhaust back pressure and the target exhaust flow rate for calculation can also effectively reduce the long-time closing of the VGT at a large degree under a dynamic condition (Tip-In), avoid the rapid and high rise of the exhaust back pressure, help the rapid establishment of the charge efficiency, and thus improve the drivability of the vehicle. In addition, since the control method is based on the optimization of the existing boost control logic, the additional calibration workload can be greatly reduced by reusing the existing calibration data of the system.

[0145] Referring to Figure 6 The embodiment of the present application also provides an electronic device 600, which comprises:

[0146] at least one processor; and

[0147] a memory connected with the at least one processor in communication; wherein

[0148] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the boost pressure determination method in the foregoing method embodiments.

[0149] The embodiment of the present application also provides a non-transitory computer readable storage medium storing computer instructions, and the computer instructions are used to make the computer perform the boost pressure determination method in the foregoing method embodiments.

[0150] The embodiment of the present application also provides a computer program product, which comprises a computer program stored on a non-transitory computer readable storage medium, and the computer program comprises program instructions, and when the program instructions are executed by a computer, the computer performs the boost pressure determination method in the foregoing method embodiments.

[0151] Reference is made below to Figure 6 which shows a structural schematic diagram of an electronic device 600 suitable for being used to implement the embodiment of the present application. The electronic device 600 in the embodiment of the present application can include but is not limited to mobile electronic devices such as notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablets), PMPs (portable multimedia players), and the like, and fixed electronic devices such as digital TVs, desktop computers, and the like. Figure 6The electronic device 600 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0152] like Figure 6 As shown, electronic device 600 may include a processing device (e.g., a central processing unit, a graphics processor, etc.) 601, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 602 or a program loaded from storage device 608 into random access memory (RAM) 603. RAM 603 also stores various programs and data required for the operation of electronic device 600. Processing device 601, ROM 602, and RAM 603 are interconnected via bus 604. Input / output (I / O) interface 605 is also connected to bus 604.

[0153] Typically, the following devices can be connected to I / O interface 605: input devices 606 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 607 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 608 including, for example, magnetic tapes, hard disks, etc.; and communication devices 609. Communication device 609 allows electronic device 600 to communicate wirelessly or wiredly with other devices to exchange data. Although an electronic device 600 with various devices is shown in the figure, it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed alternatively.

[0154] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 609, or installed from a storage device 608, or installed from a ROM 602. When the computer program is executed by the processing device 601, it performs the functions defined in the methods of the embodiments of this application.

[0155] It should be noted that the computer-readable medium in the present disclosure can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, device or apparatus, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device or apparatus. In the present disclosure, the computer-readable signal medium can include a data signal carried in a baseband or as a part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to an electromagnetic signal, an optical signal or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, which can send, propagate or transmit a program for use by or in conjunction with an instruction execution system, device or apparatus. The program code contained in the computer-readable medium can be transmitted by any suitable medium, including but not limited to a wire, a cable, an RF (radio frequency) or the like, or any suitable combination of the above.

[0156] The computer-readable medium described above can be contained in the electronic device described above; or can exist separately and not be assembled into the electronic device.

[0157] The computer-readable medium described above carries one or more programs, which, when executed by the electronic device, cause the electronic device to: obtain at least two Internet protocol addresses; send a node evaluation request including the at least two Internet protocol addresses to a node evaluation device, wherein the node evaluation device selects an Internet protocol address from the at least two Internet protocol addresses and returns; receive the Internet protocol address returned by the node evaluation device; and wherein the obtained Internet protocol address indicates an edge node in a content distribution network.

[0158] Alternatively, the computer readable medium described above carries one or more programs, when the one or more programs are executed by the electronic device, the electronic device is caused to: receive a node evaluation request comprising at least two internet protocol addresses; select an internet protocol address from the at least two internet protocol addresses; and return the selected internet protocol address; wherein the received internet protocol address indicates an edge node in a content distribution network.

[0159] Computer program code for carrying out operations of the present disclosure can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0160] The flow diagrams and the block diagrams in the drawings are illustrations of architectures, functionalities, and operations of possible implementations of systems, methods, and computer program products according to various embodiments of present disclosure. In this regard, each block in the flow diagrams or block diagrams can represent a module, a procedure, or a part of code, which comprises one or more executable instructions for implementing the specific logical functions specified for the block. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or in the reverse order, depending on the functionality involved. It is also noted that each block of the block diagrams and / or flow diagrams and combinations of blocks in the block diagrams and / or flow diagrams can be implemented by dedicated hardware-based systems that perform the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0161] The units described in the embodiments of the present application can be implemented by software or by hardware. In some cases, the name of the unit does not constitute a limitation on the unit itself, for example, the first obtaining unit can also be described as "a unit for obtaining at least two internet protocol addresses".

Claims

1. A method for determining boosting pressure, characterized in that, include: The target intake flow rate of the engine is determined based on the required charging efficiency of the engine. The target exhaust flow rate of the engine is determined based on the target intake flow rate and the air-fuel ratio. Based on the target exhaust flow rate and the reference boost pressure, the target opening of the variable geometry turbine of the engine is determined, and the reference boost pressure is the target boost pressure determined in the previous calculation process. The target exhaust back pressure of the engine is determined based on the target exhaust flow rate and the target opening. Based on the target exhaust back pressure and the required charging efficiency, the current target boost pressure of the engine is determined; The determination of the target opening of the variable geometry turbine of the engine, based on the target exhaust flow rate and the reference boost pressure, includes: determining the adiabatic compression work of the compressor based on the reference boost pressure, the downstream flow rate demand of the compressor, the upstream temperature of the compressor, the compressor efficiency, the compressor's intake specific heat capacity, the compressor's upstream pressure, and the ideal gas adiabatic index; determining the required power of the variable geometry turbine based on the adiabatic compression work; determining the target turbine expansion ratio of the variable geometry turbine based on the target exhaust flow rate, the upstream temperature of the variable geometry turbine, the efficiency of the variable geometry turbine, the exhaust specific heat capacity, and the exhaust ideal gas adiabatic index, wherein the target turbine expansion ratio is the ratio of the downstream pressure to the upstream pressure of the variable geometry turbine; and determining the target opening of the variable geometry turbine based on the target exhaust flow rate, the target turbine expansion ratio, the effective cross-sectional area of ​​the variable geometry turbine, and the flow correction coefficient. Determining the current target boost pressure of the engine based on the target exhaust back pressure and the required charging efficiency includes: determining the target residual exhaust gas partial pressure in the cylinder of the engine based on the target exhaust back pressure and the reference boost pressure; and determining the target boost pressure based on the target residual exhaust gas partial pressure and the charging partial pressure corresponding to the required charging efficiency.

2. The method for determining the boosting pressure as described in claim 1, characterized in that, The determination of the target intake flow rate of the engine based on the engine's required charging efficiency includes: The target intake flow rate of the engine is obtained by multiplying the required inflation efficiency by a first conversion factor, which is related to the engine speed.

3. The method for determining the boosting pressure as described in claim 1, characterized in that, Determining the target exhaust flow rate of the engine based on the target intake flow rate and the air-fuel ratio includes: The air-fuel coefficient is added to the first value to obtain the second conversion coefficient, wherein the air-fuel coefficient is related to the excess air coefficient and the air-fuel ratio; The target intake flow rate is obtained by multiplying the target intake flow rate by the second conversion coefficient.

4. The method for determining the boosting pressure as described in claim 1, characterized in that, Determining the target exhaust back pressure of the engine based on the target exhaust flow rate and the target opening includes: Substituting the target exhaust flow rate and the target opening degree into the valve port flow equation, the target exhaust back pressure is obtained.

5. The method for determining the boosting pressure as described in claim 1, characterized in that, The determination of the target boost pressure based on the target residual exhaust gas partial pressure and the inflation partial pressure corresponding to the required inflation efficiency includes: Substituting the target residual exhaust gas partial pressure and the inflation partial pressure corresponding to the required inflation efficiency into the ideal gas equation, the target boost pressure is obtained.

6. The method for determining the boosting pressure as described in claim 1, characterized in that, After determining the current target boost pressure of the engine based on the target exhaust back pressure and the required charging efficiency, the method further includes: The opening of the variable geometry turbine of the engine is adjusted based on the target boost pressure and the target exhaust flow rate.

7. A device for determining boosting pressure, comprising: The target intake volume determination module is used to determine the target intake flow rate of the engine based on the engine's required charging efficiency. The target exhaust flow rate determination module is used to determine the target exhaust flow rate of the engine based on the target intake flow rate and the air-fuel ratio; The target opening determination module is used to determine the target opening of the variable geometry turbine of the engine based on the target exhaust flow rate and the reference boost pressure, wherein the reference boost pressure is the target boost pressure determined in the previous calculation process. The step of determining the target opening of the variable geometry turbine of the engine based on the target exhaust flow rate and the reference boost pressure includes: determining the adiabatic compression work of the compressor based on the reference boost pressure, the downstream flow rate demand of the compressor, the upstream temperature of the compressor, the efficiency of the compressor, the specific heat capacity of the compressor intake air, the upstream pressure of the compressor, and the ideal gas adiabatic index; determining the required power of the variable geometry turbine of the compressor based on the adiabatic compression work; determining the target turbine expansion ratio of the variable geometry turbine based on the target exhaust flow rate, the upstream temperature of the variable geometry turbine, the efficiency of the variable geometry turbine, the exhaust specific heat capacity, and the exhaust ideal gas adiabatic index, wherein the target turbine expansion ratio is the ratio of the downstream pressure to the upstream pressure of the variable geometry turbine; and determining the target opening of the variable geometry turbine based on the target exhaust flow rate, the target turbine expansion ratio, the effective cross-sectional area of ​​the variable geometry turbine, and the flow correction coefficient. The target exhaust back pressure determination module is used to determine the target exhaust back pressure of the engine based on the target exhaust flow rate and the target opening degree. The target boost pressure determination module is used to determine the current target boost pressure of the engine based on the target exhaust back pressure and the required charging efficiency. Determining the current target boost pressure of the engine based on the target exhaust back pressure and the required charging efficiency includes: determining the target residual exhaust gas partial pressure within the engine cylinder based on the target exhaust back pressure and the reference boost pressure; and determining the target boost pressure based on the target residual exhaust gas partial pressure and the charging partial pressure corresponding to the required charging efficiency.

8. An electronic device, characterized in that, The electronic device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the method for determining the boost pressure as described in any one of claims 1-6.

9. A non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the method for determining the boost pressure according to any one of claims 1-6.

Images