Determination method and device for exhaust pressure and vehicle

Abstract

The invention discloses an exhaust pressure determining method and device and a vehicle, and belongs to the field of vehicle control. The method comprises the steps that the environment pressure of a vehicle is obtained, and first pressure is determined based on the environment pressure and silencer pressure drop; determining a second pressure using the first pressure and the catalyst pressure drop; determining an exhaust correction factor using at least one of an exhaust flow of a vehicle exhaust system, a pressure ratio before and after a throttle valve, or a wastegate position; and the second pressure is corrected through the exhaust correction coefficient, and the exhaust pressure corresponding to the engine of the vehicle is obtained. The first pressure and the second pressure are determined through the environment pressure, the silencer pressure drop and the catalyst pressure drop, the dependence of an exhaust system on a pressure sensor is reduced, and the hardware cost is reduced; the exhaust correction coefficient is determined through the exhaust flow, the pressure ratio before and after the throttle valve and the position of the waste gas valve, the exhaust pressure is determined through the exhaust correction coefficient and the second pressure, and the accuracy of the determined exhaust pressure can be improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of vehicle control, and in particular, to a method and device for determining exhaust pressure and a vehicle. Background Art

[0002] With the rapid development of the automotive industry, the structure of the engine exhaust system has become increasingly complex, and there are certain differences in the exhaust systems corresponding to different engine models. By determining the exhaust pressure of the exhaust system, it can be determined whether the engine exhaust system is in a normal working state.

[0003] In the related art, a pressure sensor is set in the exhaust system to monitor the exhaust pressure of the exhaust system through the pressure sensor. The accuracy of the exhaust pressure depends on the coverage density and measurement accuracy of the hardware sensor, and the cost of determining the exhaust pressure is high and the flexibility is poor; in the case of a complex exhaust system, the accuracy of the exhaust pressure measured by the pressure sensor is poor. Summary of the Invention

[0004] Embodiments of the present application provide a method and device for determining exhaust pressure and a vehicle, which can improve the accuracy of the determined exhaust pressure. The technical solutions are as follows:

[0005] On the one hand, embodiments of the present application provide a method for determining exhaust pressure, the method including:

[0006] Obtain the ambient pressure where the vehicle is located, and determine a first pressure based on the ambient pressure and the muffler pressure drop, where the first pressure is the pressure at the end of the muffler close to the vehicle engine;

[0007] Use the first pressure and the catalytic converter pressure drop to determine a second pressure, where the second pressure is the pressure at the end of the catalytic converter close to the vehicle engine;

[0008] Determine an exhaust correction coefficient by using at least one of the exhaust flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle, or the position of the waste gas valve;

[0009] Use the exhaust correction coefficient to correct the second pressure to obtain the exhaust pressure corresponding to the vehicle engine.

[0010] On the other hand, embodiments of the present application provide a device for determining exhaust pressure, the device including:

[0011] A determination module, configured to obtain the ambient pressure where the vehicle is located, and determine a first pressure based on the ambient pressure and the muffler pressure drop, where the first pressure is the pressure at the end of the muffler close to the vehicle engine;

[0012] The determining module is further configured to determine a second pressure by using the first pressure and the pressure drop of the catalytic converter, where the second pressure is the pressure at the end of the catalytic converter close to the vehicle engine;

[0013] The determining module is further configured to determine an exhaust correction coefficient by using at least one of the exhaust gas flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve;

[0014] The correction module is configured to correct the second pressure by using the exhaust correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0015] In a possible implementation manner, the determining module is configured to determine a first correction coefficient by using the exhaust gas flow rate and the exhaust gas flow rate correction curve, where the exhaust gas flow rate correction curve represents the pressure deviation at different exhaust gas flow rates; determine a second correction coefficient by using the pressure ratio before and after the throttle valve and the pressure ratio correction coefficient calibration table, where the pressure ratio correction coefficient calibration table represents the influence of the intake system pressure change on the exhaust pressure at different pressures; determine a third correction coefficient by using the position of the waste gas valve, the position sensitivity coefficient, and the basic position of the waste gas valve; obtain the driving parameters of the vehicle, and determine a first weight corresponding to the first correction coefficient, a second weight corresponding to the second correction coefficient, and a third weight corresponding to the third correction coefficient based on the driving parameters; calculate the weighted average of the first correction coefficient, the first weight, the second correction coefficient, the second weight, the third correction coefficient, and the third weight to obtain the exhaust correction coefficient.

[0016] In a possible implementation manner, the determining module is configured to determine a basic correction coefficient based on the relationship between the pressure ratio before and after the throttle valve and the position of the waste gas valve and a correction function, where the correction function includes at least one of a piecewise function or a polynomial fitting function; perform weighted adjustment on the basic correction coefficient by using the exhaust gas flow rate to obtain the exhaust correction coefficient.

[0017] In a possible implementation manner, the determining module is further configured to determine the pressure drop of the muffler by using the pressure drop coefficient of the muffler, the exhaust gas flow rate of the muffler, and the flow index, where the pressure drop coefficient of the muffler represents the resistance of the muffler to the air flow, and the flow index represents the linear relationship between the pressure drop and the flow rate;

[0018] The determining module is configured to determine the sum of the ambient pressure and the pressure drop of the muffler as the first pressure.

[0019] In a possible implementation, the determining module is further configured to obtain a flow pressure drop table corresponding to the catalytic converter, where the flow pressure drop table characterizes the mapping relationship between the exhaust gas flow rate and the pressure drop value; when the exhaust gas flow rate of the catalytic converter has a matching exhaust gas flow rate in the flow pressure drop table, determine the catalytic converter pressure drop corresponding to the exhaust gas flow rate of the catalytic converter based on the mapping relationship between the exhaust gas flow rate and the pressure drop value; or, when the exhaust gas flow rate of the catalytic converter does not have a matching exhaust gas flow rate in the flow pressure drop table, use the interpolation method to determine at least two reference exhaust gas flow rates in the flow pressure drop table, and determine the catalytic converter pressure drop corresponding to the exhaust gas flow rate of the catalytic converter by using the pressure drop values corresponding to the reference exhaust gas flow rates.

[0020] In a possible implementation, the catalytic converter includes a main catalytic converter and a pre-catalytic converter, and the determining module is further configured to determine the main catalytic converter pressure drop by using the exhaust gas flow rate of the main catalytic converter, and determine the pre-catalytic converter pressure drop by using the exhaust gas flow rate of the pre-catalytic converter; determine the sum of the main catalytic converter pressure drop and the pre-catalytic converter pressure drop as the catalytic converter pressure drop.

[0021] In a possible implementation, the determining module is further configured to obtain the temperature data of the vehicle exhaust system; determine the temperature correction coefficient by using the temperature data and the material thermal expansion coefficients corresponding to the respective components of the vehicle exhaust system, where the respective components include at least one of a muffler or a catalytic converter;

[0022] The determining module is configured to correct the second pressure by using the exhaust correction coefficient and the temperature correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0023] In a possible implementation, the determining module is further configured to obtain the oxygen sensor data of the vehicle and determine the mixed gas concentration correction coefficient corresponding to the oxygen sensor data;

[0024] The determining module is configured to correct the second pressure by using the exhaust correction coefficient, the temperature correction coefficient, and the mixed gas concentration correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0025] On the other hand, an embodiment of the present application provides a vehicle, where the vehicle includes: a vehicle body, and the vehicle body includes a vehicle exhaust system; a vehicle control system configured to perform the exhaust pressure determination method according to any one of the above on the vehicle body.

[0026] On the other hand, an embodiment of the present application provides a computer device, which includes a processor and a memory. At least one program code is stored in the memory, and the at least one program code is loaded and executed by the processor so that the computer device implements the method for determining the exhaust pressure described in any one of the above.

[0027] On the other hand, a computer-readable storage medium is also provided. At least one program code is stored in the computer-readable storage medium, and the at least one program code is loaded and executed by a processor so that a computer implements the method for determining the exhaust pressure described in any one of the above.

[0028] On the other hand, a computer program or a computer program product is also provided. At least one computer instruction is stored in the computer program or the computer program product, and the at least one computer instruction is loaded and executed by a processor so that a computer implements any one of the above methods for determining the exhaust pressure.

[0029] The technical solution provided by the embodiment of the present application at least brings the following beneficial effects:

[0030] Based on the ambient pressure, the muffler pressure drop, and the catalytic converter pressure drop, the present application gradually determines the first pressure and the second pressure, reduces the dependence on the pressure sensor inside the exhaust system, eliminates the need to deploy sensors at nodes such as the muffler and the catalytic converter, reduces the hardware cost and maintenance complexity, and improves the flexibility of determining the exhaust pressure; by using multiple parameters such as the exhaust gas flow rate, the pressure ratio before and after the throttle valve, and the position of the waste gas valve to determine the exhaust correction coefficient, and using the correction coefficient and the second pressure to determine the exhaust pressure corresponding to the engine, the accuracy of the determined exhaust pressure can be improved. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a schematic diagram of an implementation environment provided by an embodiment of the present application;

[0033] Figure 2 It is a flowchart of a method for determining the exhaust pressure of a vehicle provided by an embodiment of the present application;

[0034] Figure 3 It is a schematic diagram of the structure of a vehicle exhaust system provided by an embodiment of the present application;

[0035] Figure 4It is a schematic diagram of a device for determining the exhaust pressure of a vehicle provided by an embodiment of the present application;

[0036] Figure 5 It is a schematic structural diagram of a server provided by an embodiment of the present application. Specific embodiments

[0037] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0038] It should be noted that the terms "first", "second", etc. in the present application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0039] Figure 1 It is a schematic diagram of an implementation environment provided by an embodiment of the present application. As Figure 1 shown, the implementation environment may include a vehicle 101 and a vehicle control system 102. The vehicle control system 102 is used to control the vehicle 101 to perform corresponding operations. The vehicle control system 102 may be located in the vehicle 101. For example, the vehicle control system 102 is an in-vehicle terminal; the vehicle control system 102 may also be located outside the vehicle 101. For example, the vehicle control system 102 is a cloud control system.

[0040] The vehicle control system 102 may be an independent server. Alternatively, the vehicle control system 102 may also be a server cluster composed of multiple servers that respectively implement different functions. Alternatively, the vehicle control system 102 may also be a cloud computing center.

[0041] The vehicle 101 may be a motor vehicle equipped with an internal combustion engine power exhaust system. The vehicle 101 may include, but is not limited to, a traditional fuel vehicle, a hybrid vehicle (Hybrid Electric Vehicle, HEV, Plug-in Hybrid Electric Vehicle, PHEV), and an alternative fuel vehicle (a vehicle fueled by natural gas).

[0042] The vehicle 101 may also have a communication function. A communication module supporting wireless communication technology or wired communication technology may be provided in the vehicle 101, and the vehicle 101 performs data interaction with the vehicle control system 102 through the communication module.

[0043] Based on the above Figure 1 shown implementation environment, an embodiment of the present application provides a method for determining exhaust pressure. As Figure 2 shown, taking the application of this method to the vehicle control system as an example, this method may include steps 201 to 204.

[0044] In step 201, obtain the ambient pressure where the vehicle is located, and determine a first pressure based on the ambient pressure and the muffler pressure drop. The first pressure is the pressure at the end of the muffler close to the vehicle engine.

[0045] In an exemplary embodiment of the present application, the ambient pressure refers to the atmospheric pressure at the location where the vehicle is located. When the vehicle is equipped with a barometric pressure sensor (such as a Micro-Electro-Mechanical Systems (MEMS) piezoresistive sensor or a capacitive sensor), the barometric pressure sensor is used to directly measure the atmospheric pressure around the vehicle, and the signal of the atmospheric pressure sensor is directly read through the vehicle's Electronic Control Unit (ECU). When the vehicle is not equipped with a pressure sensor, the ambient pressure where the vehicle is located can be determined by combining the altitude data obtained by the Global Positioning System (GPS) with the standard atmosphere model and the temperature of the vehicle environment.

[0046] The vehicle 101 may include a vehicle exhaust system. Figure 3 is a schematic structural diagram of a vehicle exhaust system provided by an embodiment of the present application. As Figure 3 shown, the vehicle exhaust system may include components. The multiple components include an engine 306, a turbocharger 305, a pre-catalytic converter 304, a main catalytic converter 303, a muffler 302, and a tailpipe 301. Each component is connected by a pipeline 307. The tailpipe 301 is the last part of the vehicle exhaust system and discharges the treated exhaust gas outside the vehicle.

[0047] Since the pipeline structure of the tailpipe 301 is generally short, the tailpipe 301 is directly connected to the environment, and there is no mechanism device in the tailpipe 301 that affects the pressure. Therefore, the pressure drop generated by the tailpipe 301 can be ignored. That is to say, the exhaust pressure at the rear end of the tailpipe 301 (i.e., the exhaust pressure at point B) is the same as the ambient pressure (i.e., the exhaust pressure at point A).

[0048] Exemplarily, the tailpipe 301 is connected to the muffler 302 through a pipeline 307. The muffler 302 reduces the exhaust noise through a multi-chamber or partition design, and at the same time generates a certain pressure drop, that is, the muffler pressure drop. The first pressure is determined by the ambient pressure and the muffler pressure drop. The first pressure is the pressure at the end of the muffler close to the vehicle engine, that is, the exhaust pressure at point C.

[0049] The process of determining the first pressure includes but is not limited to: determining the muffler pressure drop by using the pressure drop coefficient of the muffler, the exhaust gas flow rate of the muffler, and the flow index. The pressure drop coefficient of the muffler characterizes the resistance of the muffler to the air flow, and the flow index characterizes the linear relationship between the pressure drop and the flow rate; the sum of the ambient pressure and the muffler pressure drop is determined as the first pressure.

[0050] Among them, the pressure drop coefficient of the muffler characterizes the resistance of the muffler to the air flow. The larger the pressure drop coefficient, the greater the resistance of the muffler to the air flow, and the greater the pressure drop generated when the air flow passes through the muffler. The pressure drop coefficient of the muffler can reflect the physical characteristics of the muffler. The physical characteristics can include but are not limited to the geometric structure and material properties of the muffler. Among them, the geometric structure can include the length, cross-sectional area, bending angle of the pipeline, etc.; the material properties can include surface roughness, etc. By experimentally measuring the pressure drop data at different flow rates and using non-linear regression fitting, the pressure drop coefficient of the muffler is obtained, so as to obtain the pressure drop coefficient table of the muffler. Among them, the pressure drop coefficient of the muffler can be obtained through the pressure drop coefficient table of the muffler, and the pressure drop coefficient table of the muffler can be obtained through testing.

[0051] The exhaust gas flow rate of the muffler refers to the volume of gas passing through the muffler per unit time. The size of the exhaust gas flow rate directly affects the pressure drop of the muffler; the greater the exhaust gas flow rate, the higher the gas flow velocity, resulting in increased frictional losses and turbulence, and the greater the pressure drop generated when the air flow passes through the muffler. Among them, the exhaust gas flow rate can be obtained through an air flow (Mass Air Flow, MAF) sensor, or can be calculated based on parameters such as engine speed, throttle opening, and intake pressure.

[0052] The flow index characterizes the linear relationship between the pressure drop and the flow rate, and reflects the rate of change of the pressure drop with the flow rate; the larger the flow index, the faster the pressure drop increases with the increase of the flow rate. For example, when the flow index is 1, it indicates that the pressure drop and the flow rate are in a linear relationship; when the flow index is other positive integers, it indicates that the pressure drop and the flow rate are in a non-linear relationship.

[0053] In the exemplary embodiment of the present application, the muffler pressure drop K1 is the pressure drop coefficient of the muffler, Q1 is the exhaust gas flow rate of the muffler, and n is the flow index. After determining the muffler pressure drop, the sum of the ambient pressure and the muffler pressure drop can be calculated to obtain the first pressure, that is, the exhaust pressure at the front end of the muffler (the exhaust pressure at point C).

[0054] In the embodiment of the present application, the pressure drop of the muffler is determined by the pressure drop coefficient, the exhaust gas flow rate, and the flow index, taking into account the influence of the internal structure of the muffler and the airflow characteristics on the pressure drop, which can improve the accuracy of the determined pressure drop of the muffler; the pressure drop of the muffler is obtained through calculation, without installing a differential pressure sensor before and after the muffler, reducing the hardware cost.

[0055] In step 202, the second pressure is determined by using the first pressure and the pressure drop of the catalytic converter, and the second pressure is the pressure at the end of the catalytic converter close to the vehicle engine.

[0056] In the exemplary embodiment of the present application, the muffler of the vehicle exhaust system is connected to the catalytic converter through a pipeline. The catalytic converter may include a main catalytic converter and a pre-catalytic converter. Among them, the main catalytic converter may also be referred to as a gasoline particulate filter (GPF) particulate trap and is connected to the pre-catalytic converter and the muffler. The main catalytic converter is mainly used to trap and store particulate matter (PM) generated by engine combustion, thereby reducing the emission of harmful substances in the exhaust gas; the main function of the pre-catalytic converter is to preliminarily catalytically convert harmful substances in the exhaust gas, such as hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx), into harmless or less harmful substances.

[0057] The process of determining the pressure drop of the catalytic converter may include: determining the pressure drop of the main catalytic converter by using the exhaust gas flow rate of the main catalytic converter, and determining the pressure drop of the pre-catalytic converter by using the exhaust gas flow rate of the pre-catalytic converter; determining the sum of the pressure drop of the main catalytic converter and the pressure drop of the pre-catalytic converter as the pressure drop of the catalytic converter.

[0058] Combined with Figure 3 , the muffler 302 is connected to the main catalytic converter 303 through the pipeline 307, and the main catalytic converter 303 is connected to the pre-catalytic converter 304 through the pipeline 307. The pressure drop of the main catalytic converter is determined by using the exhaust gas flow rate of the main catalytic converter, that is, the pressure drop between point D and point C; the pressure drop of the pre-catalytic converter is determined by using the exhaust gas flow rate of the pre-catalytic converter, that is, the pressure drop between point E and point D. Then, the pressure drop of the main catalytic converter and the pressure drop of the pre-catalytic converter are determined as the pressure drop of the entire catalytic converter. On the basis of the first pressure, the pressure drop of the entire catalytic converter is increased to obtain the second pressure, that is, the exhaust pressure at point E.

[0059] The catalytic converter is one of the main catalytic converter or the pre-catalytic converter. The process of determining the pressure drop of the catalytic converter by any catalytic converter includes, but is not limited to: obtaining the flow-pressure drop table corresponding to the catalytic converter, where the flow-pressure drop table characterizes the mapping relationship between the exhaust gas flow rate and the pressure drop value; when the exhaust gas flow rate of the catalytic converter has a matching exhaust gas flow rate in the flow-pressure drop table, determining the pressure drop of the catalytic converter corresponding to the exhaust gas flow rate of the catalytic converter based on the mapping relationship between the exhaust gas flow rate and the pressure drop value; or, when the exhaust gas flow rate of the catalytic converter does not have a matching exhaust gas flow rate in the flow-pressure drop table, using the interpolation method to determine at least two reference exhaust gas flow rates in the flow-pressure drop table, and using the pressure drop values corresponding to the reference exhaust gas flow rates to determine the pressure drop of the catalytic converter corresponding to the exhaust gas flow rate of the catalytic converter.

[0060] Exemplarily, by changing the exhaust gas flow rate of the catalytic converter through experiments or simulation data, measuring the pressure difference between the inlet and outlet of the catalytic converter, and obtaining multiple sets of data of the exhaust gas flow rate and the pressure difference (pressure drop) between the inlet and outlet of the catalytic converter, thereby obtaining the mapping relationship between the exhaust gas flow rate and the pressure drop value, that is, the flow-pressure drop table.

[0061] Directly search for the current exhaust gas flow rate of the catalytic converter in the flow-pressure drop table. If the current exhaust gas flow rate has exactly the same flow rate value in the flow-pressure drop table, that is, the exhaust gas flow rate of the catalytic converter matches the exhaust gas flow rate in the flow-pressure drop table, directly read the pressure drop value corresponding to the exhaust gas flow rate in the flow-pressure drop table to obtain the pressure drop of the catalytic converter.

[0062] If the current exhaust gas flow rate does not have exactly the same flow rate value in the flow-pressure drop table, that is, the exhaust gas flow rate of the catalytic converter does not match the exhaust gas flow rate in the flow-pressure drop table, determine two exhaust gas flow rates adjacent to the current exhaust gas flow rate in the flow-pressure drop table, that is, the reference exhaust gas flow rates. For example, the exhaust gas flow rate of the catalytic converter is Q2, and the reference exhaust gas flow rate Q i The corresponding pressure drop is P i ,the reference exhaust gas flow rate Q j The corresponding pressure drop is P j ,the pressure drop ΔP2 of the catalytic converter corresponding to the exhaust gas flow rate Q2 of the catalytic converter can be calculated by formula (1):

[0063]

[0064] It should be noted that in this application, it is described with the number of reference exhaust gas flow rates being two. Two or more reference exhaust gas flow rates can also be selected to calculate the pressure drop of the catalytic converter, construct a quadratic or cubic polynomial fitting curve, and calculate the pressure drop of the catalytic converter corresponding to the exhaust gas flow rate of the catalytic converter. This application does not limit this.

[0065] In the embodiment of the present application, a flow pressure drop table is generated based on measured or simulated data. When the exhaust gas flow rate exists in the flow pressure drop table, the pressure drop value is directly read to avoid the approximate error of the catalyst pressure drop. When the exhaust gas flow rate does not exist in the flow pressure drop table, the interpolation method is used to determine the reference exhaust gas flow rate, and the reference exhaust gas flow rate is used to calculate the catalyst pressure drop, eliminating the step error to a certain extent, avoiding the catalyst pressure drop error caused by the "jump" of the exhaust gas flow rate, and improving the accuracy of the calculated catalyst pressure drop. Moreover, the catalyst pressure drop is obtained through calculation, without installing a differential pressure sensor before and after the catalyst, reducing the hardware cost.

[0066] Optionally, when the exhaust gas flow rate of the catalyst exceeds the maximum value of the exhaust gas flow rate in the flow pressure drop table, an extrapolation model is enabled or a flow overload alarm is triggered. For example, based on the data in the pressure drop table, the pressure drop value of the out-of-range flow rate is predicted by using the method of linear interpolation or polynomial fitting, so as to obtain the catalyst pressure drop. Or, an information indicating that the exhaust gas flow rate is too large is sent, and the ECU can adjust the vehicle parameters to limit the exhaust gas flow rate to protect the catalyst.

[0067] Optionally, when the exhaust gas flow rate of the catalyst is less than the minimum value of the exhaust gas flow rate in the flow pressure drop table, it is processed according to the minimum flow rate value or a low-flow compensation algorithm is enabled. For example, when the influence of the low flow rate on the catalyst performance is small, the pressure drop corresponding to the minimum flow rate value in the flow pressure drop table is directly used as the catalyst pressure drop, or the performance degradation at low flow rates is compensated by adjusting the control parameters (such as fuel injection quantity, ignition advance angle), that is, the difference between the actual flow rate and the minimum flow rate is monitored, and the engine control parameters are adjusted according to the difference.

[0068] In step 203, the exhaust gas correction coefficient is determined by using at least one of the exhaust gas flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve.

[0069] In an embodiment of the present application, the process of determining the exhaust gas correction coefficient includes but is not limited to steps 2031 to 2035.

[0070] In step 2031, the first correction coefficient is determined by using the exhaust gas flow rate and the exhaust gas flow rate correction curve, and the exhaust gas flow rate correction curve represents the pressure deviation at different exhaust gas flow rates.

[0071] Exemplarily, the actual pressure deviation at different exhaust gas flow rates is measured through experiments or simulation data, and an exhaust gas flow rate correction curve is obtained. Among them, the exhaust gas flow rate correction curve can be a piecewise function. The independent variable of the piecewise function is the exhaust gas flow rate, and the dependent variable is the first correction coefficient. For example, when the exhaust gas flow rate is less than the first threshold, it corresponds to the first correction curve; when the exhaust gas flow rate is greater than or equal to the first threshold and less than or equal to the second threshold, it corresponds to the second correction curve; when the exhaust gas flow rate is greater than the second threshold, it corresponds to the third correction curve. The first correction coefficient β1 is determined by the current exhaust gas flow rate and the correction curve where the exhaust gas flow rate is located.

[0072] In step 2032, the second correction coefficient is calibrated using the pressure ratio before and after the throttle valve and the pressure ratio correction coefficient calibration table, which characterizes the influence of the intake system pressure change on the exhaust pressure under different pressures.

[0073] Exemplarily, the pressure ratio (PR) before and after the throttle valve refers to the ratio of the pressure before the throttle valve to the pressure after the throttle valve. The pressure ratio before and after the throttle valve can also be referred to as the throttle pressure ratio. The correction coefficients corresponding to different throttle pressure ratios are calibrated through experiments or simulation data to obtain the pressure ratio correction coefficient calibration table. The second correction coefficient β2 is obtained by looking up the pressure ratio correction coefficient calibration table using the current pressure ratio before and after the throttle valve. It should be noted that the process of obtaining the second correction coefficient β2 by looking up the differential pressure ratio correction coefficient calibration table is similar to the process of obtaining the catalyst pressure drop by looking up the flow pressure drop table, and the relevant description in step 202 can be referred to here and will not be elaborated further.

[0074] In step 2033, the third correction coefficient is determined using the exhaust gas valve position, the position sensitivity coefficient, and the exhaust gas valve base position.

[0075] In the exemplary embodiment of the present application, the exhaust gas valve position can be represented in the form of a percentage. 0% indicates that the exhaust gas valve is in the closed state, and 100% indicates that the exhaust gas valve is in the fully open state; the position sensitivity coefficient characterizes the influence intensity of the unit opening change of the exhaust gas valve on the correction coefficient; the exhaust gas valve base position can be the reference opening, usually the opening under the design condition, such as the reference opening is 50%. The third correction coefficient β3 = 1 + position sensitivity coefficient × (exhaust gas valve position - exhaust gas valve base position).

[0076] In step 2034, the driving parameters of the vehicle are obtained, and the first weight corresponding to the first correction coefficient, the second weight corresponding to the second correction coefficient, and the third weight corresponding to the third correction coefficient are determined based on the driving parameters.

[0077] Exemplarily, the driving parameters may include, but are not limited to, vehicle speed and engine load. Different weights may be assigned to the correction factors under different driving parameters. For example, when the vehicle speed is relatively low, the correction factor is more dependent on the exhaust flow correction. Therefore, the weight of the first correction factor corresponding to the exhaust flow, that is, the first weight, may be appropriately increased; when the vehicle speed is relatively high, the correction factor is more dependent on the pressure ratio correction before and after the throttle valve. Therefore, the weight of the second correction factor corresponding to the pressure ratio before and after the throttle valve, that is, the second weight, may be appropriately increased; when the load is high, the correction factor is more dependent on the wastegate position correction. Therefore, the weight of the third correction factor corresponding to the wastegate position, that is, the third weight, may be appropriately increased.

[0078] In step 2035, the weighted average of the first correction factor, the first weight, the second correction factor, the second weight, the third correction factor, and the third weight is calculated to obtain the exhaust correction factor.

[0079] Exemplarily, after determining each correction factor and the weight corresponding to each correction factor, the exhaust correction factor β may be calculated based on formula (2):

[0080]

[0081] In the above formula (2), w1 is the first weight, w2 is the second weight, and w3 is the third weight.

[0082] In the embodiment of the present application, the exhaust correction factor is calculated through the first correction factor, the second correction factor, and the third correction factor corresponding to the three parameters of flow rate, throttle pressure ratio, and wastegate position, and the weights corresponding to each correction factor under different driving parameters. The exhaust pressure is corrected collaboratively through multi-dimensional parameters, which can cover the correction of the exhaust pressure by the exhaust correction factor under different working conditions (such as rapid acceleration, uniform speed, high altitude), improve the accuracy of the determined exhaust correction factor, and thus improve the accuracy of the determined exhaust pressure in the subsequent process.

[0083] In another embodiment of the present application, the process of determining the exhaust correction factor includes, but is not limited to, steps 2036 to 2037.

[0084] In step 2036, the basic correction factor β is determined based on the relationship between the pressure ratio before and after the throttle valve and the wastegate position and the correction function base , and the correction function includes at least one of a piecewise function or a polynomial fitting function.

[0085] Exemplarily, under steady-state and transient conditions (such as throttle step change, rapid adjustment of the exhaust gas valve), the pressure ratio before and after the throttle and the actual deviation between the exhaust gas valve position and the exhaust pressure are measured and fitted to obtain a correction function. Based on the dynamic relationship between the pressure ratio before and after the throttle and the exhaust gas valve position and the correction function, a basic correction coefficient is obtained. Among them, the fitting can be at least one of piecewise fitting or polynomial fitting.

[0086] In step 2037, the basic correction coefficient is weighted and adjusted using the exhaust gas flow rate to obtain an exhaust gas correction coefficient.

[0087] After determining the basic correction coefficient, the weight of the basic correction coefficient is dynamically adjusted according to the real-time exhaust gas flow rate to generate a final exhaust gas correction coefficient to optimize the correction intensity under different flow conditions. Among them, the weighted adjustment can include linear weighted adjustment and exponential weighted adjustment. For example, the linear weighted adjustment is adjusted through a linear function, w (Q) = mQ + n, where w (Q) is the adjustment parameter, Q is the exhaust gas flow rate, m and n are adjustment parameters, and m and n can be set based on the actual situation. Another example is w (Q) = γe λQ , γ is the adjustment base number, which determines the starting amplitude of the weight curve; λ is the growth coefficient, which is used to control the rate of weight growth with the increase of flow rate. After determining the adjustment parameters, using β = β base × w (Q) to obtain the exhaust gas correction coefficient β.

[0088] In the embodiment of the present application, through the combined correction function of the pressure ratio before and after the throttle and the exhaust gas valve position, the interactive influence of intake resistance and exhaust gas path change is considered when determining the basic correction coefficient; then the basic correction coefficient is further corrected using the exhaust gas flow rate to obtain the exhaust gas correction coefficient, which can improve the accuracy of the determined exhaust gas correction coefficient, thereby improving the accuracy of the exhaust pressure determined in the subsequent process.

[0089] In step 204, the second pressure is corrected using the exhaust gas correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0090] In the exemplary embodiment of the present application, the process of determining the exhaust pressure corresponding to the engine of the vehicle includes but is not limited to Case 1 to Case 3.

[0091] Case 1, after determining the exhaust gas correction coefficient and the second pressure, the second pressure can be directly corrected using the exhaust gas correction coefficient. For example, by calculating the product of the exhaust gas correction coefficient and the second pressure, the exhaust pressure corresponding to the engine is obtained. Among them, the exhaust pressure corresponding to the engine can also be referred to as the exhaust back pressure at the exhaust manifold of the engine, that is, Figure 3 the exhaust pressure at point E in

[0092] In Case 2, the process of determining the exhaust pressure corresponding to the vehicle's engine may include: obtaining temperature data of the vehicle exhaust system; determining a temperature correction coefficient by using the temperature data and the material thermal expansion coefficients corresponding to the various components of the vehicle exhaust system, where the components include at least one of a muffler or a catalytic converter; and correcting the second pressure by using the exhaust correction coefficient and the temperature correction coefficient to obtain the exhaust pressure corresponding to the vehicle's engine.

[0093] Exemplarily, the real-time measured temperature of the key components of the exhaust system, i.e., the temperature data, is obtained by a temperature sensor installed on the surface or inside of the exhaust pipe. At different temperatures, the material thermal expansion coefficients of the various components of the vehicle exhaust system may be different. For example, at high temperatures, the materials of the various components will expand, resulting in changes in the geometric dimensions of the components, which in turn affect the exhaust gas flow rate. The temperature correction coefficient K temp can be calculated by formula (3):

[0094] K temp = 1 + α(T m - T ref ) Formula (3)

[0095] In the above formula (3), α is the average thermal expansion coefficient of the component material, T m is the real-time measured temperature, and T ref is the reference temperature, and the reference temperature can be the current ambient temperature. If multiple components are involved, such as a muffler and a catalytic converter, the weighted average of the temperature correction coefficients can be used as the final temperature correction coefficient.

[0096] After determining the temperature correction coefficient, the second pressure can be corrected jointly by using the exhaust correction coefficient and the temperature correction coefficient to obtain the exhaust pressure corresponding to the vehicle's engine. For example, the exhaust pressure corresponding to the engine is the product of the second pressure, the exhaust correction coefficient, and the temperature correction coefficient.

[0097] In the embodiment of the present application, the temperature correction coefficient is determined by the temperature data and the material thermal expansion coefficients corresponding to the various components, and the second pressure is corrected jointly by the temperature correction coefficient and the exhaust correction coefficient to obtain the exhaust pressure, which can improve the accuracy of the engine exhaust pressure.

[0098] In Case 3, the process of determining the exhaust pressure corresponding to the vehicle's engine may include: obtaining the oxygen sensor data of the vehicle and determining the mixture gas concentration correction coefficient corresponding to the oxygen sensor data; and correcting the second pressure by using the exhaust correction coefficient, the temperature correction coefficient, and the mixture gas concentration correction coefficient to obtain the exhaust pressure corresponding to the vehicle's engine.

[0099] Exemplarily, the exhaust system of a vehicle is configured with an oxygen sensor (such as a wide - range oxygen sensor). By using the oxygen sensor, the oxygen concentration in the exhaust gas can be measured, and thus the concentration of the mixed gas can be obtained, which can also be referred to as the air - fuel ratio. For example, the oxygen sensor is installed in front of the catalytic converter (upstream oxygen sensor) and behind the catalytic converter (downstream oxygen sensor); the air - fuel ratio refers to the mass ratio of air required for complete combustion of fuel to fuel. For example, the theoretical air - fuel ratio of gasoline is 14.7:1. The correction coefficient K of the mixed gas concentration AFR can be calculated by formula (4):

[0100] K AFR = 1 + τ(K m - 1) Formula (4)

[0101] In the above formula (4), τ is the correction coefficient sensitivity, indicating the degree of influence of the change in the value of K m on the correction coefficient K of the mixed gas concentration AFR ; K m is the ratio of the actual air - fuel ratio to the theoretical air - fuel ratio, and the actual air - fuel ratio is obtained based on the oxygen sensor data. If multiple components are involved, such as a muffler and a catalytic converter, the weighted average of the correction coefficients of the mixed gas concentration is used as the final correction coefficient of the mixed gas concentration.

[0102] After determining the correction coefficient of the mixed gas concentration, the second pressure can be corrected jointly by using the exhaust correction coefficient, the temperature correction coefficient, and the correction coefficient of the mixed gas concentration to obtain the exhaust pressure corresponding to the engine of the vehicle. For example, the exhaust pressure corresponding to the engine is the product of the second pressure, the exhaust correction coefficient, the temperature correction coefficient, and the correction coefficient of the mixed gas concentration.

[0103] In the embodiment of the present application, the correction coefficient of the mixed gas concentration is determined through the oxygen sensor data. The correction coefficient of the mixed gas concentration can correct the influence of the changes in the density and flow rate of the mixed gas on the exhaust pressure, reducing the error caused by combustion fluctuations; by jointly correcting the second pressure with the temperature correction coefficient, the correction coefficient of the mixed gas concentration, and the exhaust correction coefficient to obtain the exhaust pressure, the accuracy of the engine exhaust pressure can be improved.

[0104] Based on the ambient pressure, the muffler pressure drop, and the catalytic converter pressure drop, the present application determines the first pressure and the second pressure step by step, reducing the dependence on the pressure sensor inside the exhaust system, eliminating the need to deploy sensors at nodes such as mufflers and catalytic converters, reducing the hardware cost and maintenance complexity, and improving the flexibility of determining the exhaust pressure; by using multiple parameters such as the exhaust flow rate, the pressure ratio before and after the throttle, and the position of the exhaust gas valve to determine the exhaust correction coefficient, and using the correction coefficient and the second pressure to determine the exhaust pressure corresponding to the engine, the accuracy of the determined exhaust pressure can be improved.

[0105] The present application also provides a device for determining the exhaust pressure of a vehicle. Figure 4 It is a schematic diagram of a device for determining the exhaust pressure of a vehicle provided by an embodiment of the present application. As Figure 4 shown, the device includes:

[0106] A determination module 401, configured to obtain the ambient pressure where the vehicle is located, and determine a first pressure based on the ambient pressure and the muffler pressure drop. The first pressure is the pressure at the end of the muffler close to the vehicle engine;

[0107] The determination module 401 is further configured to determine a second pressure by using the first pressure and the catalytic converter pressure drop. The second pressure is the pressure at the end of the catalytic converter close to the vehicle engine;

[0108] The determination module 401 is further configured to determine an exhaust correction coefficient by using at least one of the exhaust flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve;

[0109] A correction module 402, configured to correct the second pressure by using the exhaust correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0110] In a possible implementation manner, the determination module 401 is configured to determine a first correction coefficient by using the exhaust flow rate and the exhaust flow rate correction curve. The exhaust flow rate correction curve characterizes the pressure deviation at different exhaust flow rates; determine a second correction coefficient by using the pressure ratio before and after the throttle valve and the pressure ratio correction coefficient calibration table. The pressure ratio correction coefficient calibration table characterizes the influence of the intake system pressure change on the exhaust pressure at different pressures; determine a third correction coefficient by using the position of the waste gas valve, the position sensitivity coefficient, and the basic position of the waste gas valve; obtain the driving parameters of the vehicle, and determine the first weight corresponding to the first correction coefficient, the second weight corresponding to the second correction coefficient, and the third weight corresponding to the third correction coefficient based on the driving parameters; calculate the weighted average of the first correction coefficient, the first weight, the second correction coefficient, the second weight, the third correction coefficient, and the third weight to obtain the exhaust correction coefficient.

[0111] In a possible implementation manner, the determination module 401 is configured to determine a basic correction coefficient based on the relationship between the pressure ratio before and after the throttle valve and the position of the waste gas valve and the correction function. The correction function includes at least one of a piecewise function or a polynomial fitting function; adjust the basic correction coefficient by weighting with the exhaust flow rate to obtain the exhaust correction coefficient.

[0112] In a possible implementation manner, the determination module 401 is further configured to determine the muffler pressure drop by using the pressure drop coefficient of the muffler, the exhaust flow rate of the muffler, and the flow index. The pressure drop coefficient of the muffler characterizes the resistance of the muffler to the air flow, and the flow index characterizes the linear relationship between the pressure drop and the flow rate;

[0113] A determination module 401, configured to determine the sum of the ambient pressure and the pressure drop of the muffler as the first pressure.

[0114] In a possible implementation, the determination module 401 is further configured to obtain a flow pressure drop table corresponding to the catalytic converter, where the flow pressure drop table characterizes the mapping relationship between the exhaust gas flow rate and the pressure drop value; when the exhaust gas flow rate of the catalytic converter has a matching exhaust gas flow rate in the flow pressure drop table, determine the catalytic converter pressure drop corresponding to the exhaust gas flow rate of the catalytic converter based on the mapping relationship between the exhaust gas flow rate and the pressure drop value; or, when the exhaust gas flow rate of the catalytic converter does not have a matching exhaust gas flow rate in the flow pressure drop table, use the interpolation method to determine at least two reference exhaust gas flow rates in the flow pressure drop table, and determine the catalytic converter pressure drop corresponding to the exhaust gas flow rate of the catalytic converter using the pressure drop values corresponding to the reference exhaust gas flow rates.

[0115] In a possible implementation, the catalytic converter includes a main catalytic converter and a pre-catalytic converter. The determination module 401 is further configured to determine the main catalytic converter pressure drop using the exhaust gas flow rate of the main catalytic converter, and determine the pre-catalytic converter pressure drop using the exhaust gas flow rate of the pre-catalytic converter; determine the sum of the main catalytic converter pressure drop and the pre-catalytic converter pressure drop as the catalytic converter pressure drop.

[0116] In a possible implementation, the determination module 401 is further configured to obtain temperature data of the vehicle exhaust system; determine a temperature correction coefficient using the temperature data and the material thermal expansion coefficients corresponding to the various components of the vehicle exhaust system, where the components include at least one of a muffler or a catalytic converter;

[0117] The determination module 401 is configured to correct the second pressure using the exhaust correction coefficient and the temperature correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0118] In a possible implementation, the determination module 401 is further configured to obtain oxygen sensor data of the vehicle and determine a mixture gas concentration correction coefficient corresponding to the oxygen sensor data;

[0119] The determination module 401 is configured to correct the second pressure using the exhaust correction coefficient, the temperature correction coefficient, and the mixture gas concentration correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

[0120] This application determines the first pressure and the second pressure step by step based on the ambient pressure, the muffler pressure drop, and the catalytic converter pressure drop, reducing the dependence on pressure sensors inside the exhaust system, eliminating the need to deploy sensors at nodes such as mufflers and catalytic converters, reducing hardware costs and maintenance complexity, and improving the flexibility of determining the exhaust pressure; determining the exhaust correction coefficient using multiple parameters such as the exhaust gas flow rate, the pressure ratio before and after the throttle, and the position of the waste gas valve, and determining the exhaust pressure corresponding to the engine using the correction coefficient and the second pressure can improve the accuracy of the determined exhaust pressure.

[0121] It should be understood that when the above-provided device implements its functions, only the division of the above-mentioned functional modules is used for illustration. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device provided in the above embodiment and the method embodiment belong to the same concept. For the specific implementation process, please refer to the method embodiment and will not be elaborated here.

[0122] An embodiment of the present application further provides a vehicle, which includes: a vehicle body, and the vehicle body includes a vehicle exhaust system; a vehicle control system for performing the above-mentioned exhaust pressure determination method on the vehicle body. The exhaust pressure determination method has been described in steps 201 to 204 and will not be elaborated here.

[0123] Figure 5 The structure diagram of the server provided by the embodiment of the present application is shown. The server 500 may vary greatly due to different configurations or performances, and may include one or more processors 501 and one or more memories 502. Among them, at least one program code is stored in the one or more memories 502, and the at least one program code is loaded and executed by the one or more processors 501 to implement the exhaust pressure determination method provided by each of the above method embodiments. Of course, the server 500 may also have components such as a wired or wireless network interface, a keyboard, and an input / output interface for input and output. The server 500 may also include other components for implementing the functions of the device, which will not be elaborated here.

[0124] In an exemplary embodiment, a computer-readable storage medium is also provided. At least one program code is stored in the storage medium, and the at least one program code is loaded and executed by a processor to enable a computer to implement any of the above exhaust pressure determination methods.

[0125] Optionally, the above computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0126] In an exemplary embodiment, a computer program or a computer program product is also provided. At least one computer instruction is stored in the computer program or the computer program product, and the at least one computer instruction is loaded and executed by a processor to enable a computer to implement any of the above exhaust pressure determination methods.

[0127] It should be noted that the information involved in this application (including but not limited to user device information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.) and signals are all authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data need to comply with the relevant laws, regulations and standards of relevant countries and regions. For example, the environmental pressure, the first pressure, the second pressure, the exhaust correction coefficient and the corresponding exhaust pressure of the engine involved in this application are all obtained under full authorization.

[0128] It should be understood that the term "a plurality of" as mentioned herein refers to two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0129] The above are only exemplary embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the principles of this application shall be included within the protection scope of this application.

Claims

1. A method for determining exhaust pressure, characterized in that, The method includes: Obtaining the ambient pressure where the vehicle is located, and determining a first pressure based on the ambient pressure and the muffler pressure drop, where the first pressure is the pressure at the end of the muffler close to the vehicle engine; Determining a second pressure by using the first pressure and the catalytic converter pressure drop, where the second pressure is the pressure at the end of the catalytic converter close to the vehicle engine; Determining an exhaust correction coefficient by using at least one of the exhaust gas flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve; Correcting the second pressure by using the exhaust correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

2. The method according to claim 1, wherein The determining the exhaust correction coefficient by using at least one of the exhaust gas flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve includes: Determining a first correction coefficient by using the exhaust gas flow rate and an exhaust gas flow rate correction curve, where the exhaust gas flow rate correction curve characterizes the pressure deviation at different exhaust gas flow rates; Determining a second correction coefficient by using the pressure ratio before and after the throttle valve and a pressure ratio correction coefficient calibration table, where the pressure ratio correction coefficient calibration table characterizes the influence of the intake system pressure change on the exhaust pressure at different pressures; Determining a third correction coefficient by using the position of the waste gas valve, the position sensitivity coefficient, and the basic position of the waste gas valve; Obtaining the driving parameters of the vehicle, and determining a first weight corresponding to the first correction coefficient, a second weight corresponding to the second correction coefficient, and a third weight corresponding to the third correction coefficient based on the driving parameters; Calculating the weighted average of the first correction coefficient, the first weight, the second correction coefficient, the second weight, the third correction coefficient, and the third weight to obtain the exhaust correction coefficient.

3. The method according to claim 1, characterized in that, The determining the exhaust correction coefficient by using at least one of the exhaust gas flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve includes: Determining a basic correction coefficient based on the relationship between the pressure ratio before and after the throttle valve and the position of the waste gas valve and a correction function, where the correction function includes at least one of a piecewise function or a polynomial fitting function; Weightedly adjusting the basic correction coefficient by using the exhaust gas flow rate to obtain the exhaust correction coefficient.

4. The method according to claim 1, wherein Before determining the first pressure based on the ambient pressure and the muffler pressure drop, it further includes: Determining the muffler pressure drop by using the pressure drop coefficient of the muffler, the exhaust gas flow rate of the muffler, and the flow index, where the pressure drop coefficient of the muffler characterizes the resistance of the muffler to the air flow, and the flow index characterizes the linear relationship between the pressure drop and the flow rate; The determining the first pressure based on the ambient pressure and the muffler pressure drop includes: Determining the sum of the ambient pressure and the muffler pressure drop as the first pressure.

5. The method according to claim 1, characterized in that Before determining the second pressure by using the first pressure and the catalytic converter pressure drop, it further includes: Obtaining a flow pressure drop table corresponding to the catalytic converter, where the flow pressure drop table characterizes the mapping relationship between the exhaust gas flow rate and the pressure drop value; In the case that the exhaust gas flow rate of the catalytic converter has a matching exhaust gas flow rate in the flow pressure drop table, determining the catalytic converter pressure drop corresponding to the exhaust gas flow rate of the catalytic converter based on the mapping relationship between the exhaust gas flow rate and the pressure drop value; or, In the case where the exhaust gas flow rate of the catalytic converter does not have a matching exhaust gas flow rate in the flow rate-pressure drop table, at least two reference exhaust gas flow rates are determined in the flow rate-pressure drop table by using the interpolation method, and the catalytic converter pressure drop corresponding to the exhaust gas flow rate of the catalytic converter is determined by using the pressure drop values corresponding to the reference exhaust gas flow rates.

6. The method according to claim 5, characterized in that, The catalytic converter includes a main catalytic converter and a pre-catalytic converter. Before determining the second pressure by using the first pressure and the catalytic converter pressure drop, it further includes: Determining the main catalytic converter pressure drop by using the exhaust gas flow rate of the main catalytic converter, and determining the pre-catalytic converter pressure drop by using the exhaust gas flow rate of the pre-catalytic converter; Determining the sum of the main catalytic converter pressure drop and the pre-catalytic converter pressure drop as the catalytic converter pressure drop.

7. The method according to any one of claims 1 to 6, characterized in that The method further includes: Obtaining the temperature data of the vehicle exhaust system; Determining a temperature correction coefficient by using the temperature data and the material thermal expansion coefficients corresponding to the respective components of the vehicle exhaust system, where the respective components include at least one of a muffler or a catalytic converter; The step of correcting the second pressure by using the exhaust correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle includes: Correcting the second pressure by using the exhaust correction coefficient and the temperature correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

8. The method according to claim 7, characterized in that, The method further includes: Obtaining the oxygen sensor data of the vehicle and determining the mixed gas concentration correction coefficient corresponding to the oxygen sensor data; The step of correcting the second pressure by using the exhaust correction coefficient and the temperature correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle includes: Correcting the second pressure by using the exhaust correction coefficient, the temperature correction coefficient, and the mixed gas concentration correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

9. An apparatus for determining the exhaust pressure of a vehicle, characterized in that, The device includes: A determination module, configured to obtain the ambient pressure where the vehicle is located, and determine a first pressure based on the ambient pressure and the muffler pressure drop, where the first pressure is the pressure at the end of the muffler close to the vehicle engine; The determination module is further configured to determine a second pressure by using the first pressure and the catalytic converter pressure drop, where the second pressure is the pressure at the end of the catalytic converter close to the vehicle engine; The determination module is further configured to determine an exhaust correction coefficient by using at least one of the exhaust gas flow rate of the vehicle exhaust system, the pressure ratio before and after the throttle valve, or the position of the waste gas valve; A correction module, configured to correct the second pressure by using the exhaust correction coefficient to obtain the exhaust pressure corresponding to the engine of the vehicle.

10. A vehicle, characterized in that, The vehicle includes: A vehicle body, where the vehicle body includes a vehicle exhaust system; A vehicle control system, configured to execute the method for determining the exhaust pressure according to any one of claims 1 to 8 above on the vehicle body.

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