Method and device for determining vehicle exhaust flow, vehicle and storage medium

Abstract

The application discloses a kind of determination method, device, vehicle and storage medium of vehicle exhaust flow, wherein the determination method of vehicle exhaust flow includes: obtaining the pressure ratio of the exhaust valve of vehicle, wherein the pressure ratio is the ratio between the pressure value of the outlet side of exhaust valve and the pressure value of the inlet side of exhaust valve;The comparison result is obtained by comparing the pressure ratio and the preset threshold value;In response to the comparison result indicating that the pressure ratio is less than the preset threshold value, the exhaust flow of the vehicle is determined based on the initial exhaust flow of the vehicle and the correction coefficient;In response to the comparison result indicating that the pressure ratio is greater than or equal to the preset threshold value, the exhaust flow of the vehicle is determined based on the flow of multiple types of gas flowing through the intake manifold of the vehicle, wherein the multiple types of gas flow include: mixed gas flow, air flow and natural gas flow.The present application solves the technical problem that the accuracy of calculating the vehicle exhaust flow in the prior art is not high, resulting in poor stability of the vehicle engine combustion.

Description

Technical Field

[0001] This invention relates to the field of automation control technology, and more specifically, to a method, apparatus, vehicle, and storage medium for determining vehicle exhaust gas flow rate. Background Technology

[0002] In natural gas engines, exhaust gas recirculation (EGR) technology is widely used to reduce combustion temperature, suppress knocking, and reduce nitrogen oxide (NOx) emissions. Its control precision directly determines the engine's emission performance, combustion stability, and fuel economy. In actual operation, the engine needs to achieve a high dynamic response and high steady-state accuracy of the target EGR rate across a wide range of speeds and loads. This is especially crucial in transient conditions and low-opening regions, where real-time and accurate control of the exhaust gas flow (EGR flow) is required.

[0003] Current technologies commonly employ lookup tables or empirical models based on the opening and pressure difference of the exhaust gas refrigerant (EGR) valve to estimate EGR flow. However, these technologies do not adequately consider the nonlinear characteristics of the EGR valve in the throttling-sensitive region. When the pressure ratio across the EGR valve approaches a critical value, even a small change in valve opening can trigger severe nonlinear fluctuations in flow, causing a significant deviation between the actual EGR amount and the target value, leading to combustion phase drift, misfire, or knocking risks. Furthermore, some existing solutions rely on multi-sensor fusion or dual-valve structures, which not only increases system complexity and cost but also makes it difficult to maintain estimation consistency across all operating conditions due to model simplification and insufficient compensation. In addition, existing control strategies lack specific modeling for the throttling-sensitive region, resulting in continuous oscillations and convergence difficulties in the low-opening range of closed-loop control, leading to poor overall robustness and making it difficult to meet the engineering application requirements of engines under multiple constraints such as high energy efficiency, low emissions, and strong transient response.

[0004] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0005] This invention provides a method, apparatus, vehicle, and storage medium for determining vehicle exhaust gas flow rate, in order to at least solve the technical problem in the prior art where inaccurate calculation of vehicle exhaust gas flow rate leads to poor combustion stability of vehicle engines.

[0006] According to one embodiment of the present invention, a method for determining the exhaust gas flow rate of a vehicle is provided, comprising: obtaining a pressure ratio value of the exhaust gas valve of the vehicle, wherein the pressure ratio value is the ratio between the pressure value at the outlet side of the exhaust gas valve and the pressure value at the inlet side of the exhaust gas valve; comparing the pressure ratio value with a preset threshold to obtain a comparison result; in response to the comparison result indicating that the pressure ratio value is less than the preset threshold, determining the exhaust gas flow rate of the vehicle based on the initial exhaust gas flow rate of the vehicle and a correction coefficient; in response to the comparison result indicating that the pressure ratio value is greater than or equal to the preset threshold, determining the exhaust gas flow rate of the vehicle based on the flow rates of multiple types of gases flowing through the intake manifold of the vehicle, wherein the multiple types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate.

[0007] Optionally, the method for determining the vehicle exhaust gas flow rate further includes: obtaining a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust gas valve; determining a first coefficient based on the pressure value at the inlet side of the exhaust gas valve and the first preset pressure value; determining a second coefficient based on the temperature value at the inlet side of the exhaust gas valve and the first preset temperature value; and determining a correction coefficient based on the first coefficient and the second coefficient.

[0008] Optionally, the method for determining the vehicle exhaust gas flow rate also includes: obtaining the opening value of the exhaust valve; and determining the initial exhaust gas flow rate based on the opening value and the pressure ratio.

[0009] Optionally, the method for determining the vehicle exhaust gas flow rate further includes: obtaining the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0010] Optionally, the method for determining the vehicle exhaust gas flow rate further includes: obtaining the engine valve opening value, engine speed, and engine displacement; determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0011] Optionally, the method for determining the vehicle exhaust gas flow rate further includes: acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; acquiring a temperature value and a pressure value at the throttle valve inlet side, and acquiring a pressure value at the throttle valve outlet side; determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0012] Optionally, the method for determining the vehicle exhaust gas flow rate also includes: obtaining the natural gas air-fuel ratio and the excess air coefficient; and determining the natural gas flow rate based on the air flow rate, the natural gas air-fuel ratio, and the excess air coefficient.

[0013] According to one embodiment of the present invention, a device for determining vehicle exhaust gas flow rate is also provided, comprising: a first acquisition module for acquiring the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value at the outlet side of the exhaust valve and the pressure value at the inlet side of the exhaust valve; a comparison module for comparing the pressure ratio value with a preset threshold to obtain a comparison result; a first determination module for determining the vehicle's exhaust gas flow rate based on the vehicle's initial exhaust gas flow rate and a correction coefficient in response to the comparison result indicating that the pressure ratio value is less than the preset threshold; and a second determination module for determining the vehicle's exhaust gas flow rate based on multiple types of gas flow rates flowing through the vehicle's intake manifold in response to the comparison result indicating that the pressure ratio value is greater than or equal to the preset threshold, wherein the multiple types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate.

[0014] Optionally, the device for determining the vehicle exhaust gas flow rate further includes: a second acquisition module for acquiring a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust valve; a third determination module for determining a first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; a fourth determination module for determining a second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; and a fifth determination module for determining a correction coefficient based on the first coefficient and the second coefficient.

[0015] Optionally, the device for determining the vehicle exhaust gas flow rate further includes: a third acquisition module for acquiring the opening value of the exhaust valve; and a sixth determination module for determining the initial exhaust gas flow rate based on the opening value and the pressure ratio value.

[0016] Optionally, the device for determining the vehicle exhaust gas flow rate further includes: a fourth acquisition module for acquiring the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and a seventh determination module for determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0017] Optionally, the fourth acquisition module includes: an acquisition unit for acquiring the engine valve opening value, engine speed, and engine displacement; a first determination unit for determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and a second determination unit for determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0018] Optionally, the device for determining vehicle exhaust gas flow further includes: a fifth acquisition module for acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; a sixth acquisition module for acquiring a temperature value and a pressure value at the throttle valve inlet side, and a pressure value at the throttle valve outlet side; an eighth determination module for determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and a ninth determination module for determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0019] Optionally, the device for determining the vehicle exhaust gas flow rate further includes: a sixth acquisition module for acquiring the natural gas air-fuel ratio and the excess air coefficient; and a tenth determination module for determining the natural gas flow rate based on the air flow rate, the natural gas air-fuel ratio, and the excess air coefficient.

[0020] According to one embodiment of the present invention, a vehicle is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the method for determining the vehicle exhaust gas flow rate as described above.

[0021] According to one embodiment of the present invention, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the method for determining vehicle exhaust gas flow rate as described above.

[0022] According to one embodiment of the present invention, a non-volatile storage medium is also provided, wherein a computer program is stored in the non-volatile storage medium, wherein the computer program is configured to execute the method for determining the vehicle exhaust gas flow rate as described above when running.

[0023] According to one embodiment of the present invention, a computer program product is also provided, which stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method for determining the vehicle exhaust gas flow rate as described above.

[0024] In this embodiment of the invention, by obtaining the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value at the exhaust valve outlet side and the pressure value at the exhaust valve inlet side, the pressure ratio value is compared with a preset threshold to obtain a comparison result. This achieves the purpose of determining the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient in response to the comparison result indicating that the pressure ratio value is less than the preset threshold. This achieves the technical effect of determining the vehicle's exhaust flow rate based on the flow rates of various types of gases flowing through the vehicle's intake manifold in response to the comparison result indicating that the pressure ratio value is greater than or equal to the preset threshold. The various types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate. This can solve the technical problem in the prior art where inaccurate calculation of vehicle exhaust flow rate leads to poor combustion stability of the vehicle engine. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0026] Figure 1 This is a flowchart of a method for determining vehicle exhaust gas flow rate according to one embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of a vehicle exhaust gas flow calculation device according to one embodiment of the present invention;

[0028] Figure 3 This is a flowchart illustrating a method for determining vehicle exhaust gas flow rate according to one embodiment of the present invention;

[0029] Figure 4 This is a structural block diagram of a vehicle exhaust gas flow determination device according to one embodiment of the present invention;

[0030] Figure 5 This is a structural block diagram of an electronic device according to one embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] According to an embodiment of the present invention, an embodiment of a method for determining vehicle exhaust gas volume is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system containing at least a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0034] This method embodiment can also be executed in an electronic device, similar control device, or vehicle-mounted terminal that includes a memory and a processor. Taking a vehicle-mounted terminal as an example, the vehicle-mounted terminal may include one or more processors and a memory for storing data. Optionally, the vehicle-mounted terminal may also include a communication device for communication functions and a display device. Those skilled in the art will understand that the above structural description is merely illustrative and does not limit the structure of the vehicle-mounted terminal. For example, the vehicle-mounted terminal may include more or fewer components than those described above, or have a different configuration than those described above.

[0035] A processor may include one or more processing units. For example, a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microprocessor, a field-programmable gate array (FPGA), a neural network processing unit (NPU), a tensor processing unit (TPU), or an artificial intelligence (AI) type processor. Different processing units may be independent components or integrated into one or more processors. In some instances, electronic devices may also include one or more processors.

[0036] The memory can be used to store computer programs, such as the computer program corresponding to the method for determining vehicle exhaust gas flow rate in this embodiment of the invention. The processor implements the aforementioned method for determining vehicle exhaust gas flow rate by running the computer program stored in the memory. The memory may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to electronic devices via a grid. Examples of such grids include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0037] The communication device is used to receive or transmit data via a grid. Specific examples of the aforementioned grid may include a wireless grid provided by the mobile terminal's communication provider. In one example, the communication device includes a network interface controller (NIC), which can connect to other grid devices via a base station to communicate with the Internet. In another example, the communication device may be a radio frequency (RF) module used for wireless communication with the Internet. In some embodiments of this solution, the communication device is used to connect to mobile devices such as mobile phones and tablets, enabling the mobile device to send commands to the vehicle-mounted terminal.

[0038] The display device can be a touchscreen liquid crystal display (LCD) or a touch display (also referred to as a "touchscreen" or "touch display screen"). This LCD allows the user to interact with the user interface of the in-vehicle terminal. In some embodiments, the in-vehicle terminal has a graphical user interface (GUI), allowing the user to interact with the GUI through finger contact and / or gestures on a touch-sensitive surface. The human-machine interaction function may include a vehicle gear shifting function, and executable instructions for performing these functions are configured / stored in one or more processor-executable computer program products or readable storage media.

[0039] Figure 1 This is a flowchart of a method for determining vehicle exhaust gas flow rate according to one embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0040] Step S101: Obtain the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side.

[0041] Optionally, the execution subject in this embodiment is a vehicle exhaust gas flow calculation device. It should be noted that other electronic devices and processors can also be used as the execution subject, and no further limitations are made here.

[0042] Specifically, such as Figure 2 As shown, the vehicle exhaust gas flow calculation device includes: 103 cooler, 104 throttle valve, 105 mixer, 106 cylinder, 107 exhaust gas bypass valve, 108 turbocharger, 109 cooler, and 110 exhaust gas valve (EGR valve). The throttle valve 104, located between the turbocharger and the mixer, controls the amount of fresh air entering the mixer 110. The exhaust gas valve 110 draws air from before the turbocharger. After being cooled by the cooler 109, the exhaust gas flows through the EGR valve, where it mixes with fresh air and natural gas in the mixer 110. The mixer is a component that mixes the exhaust gas flowing through the EGR valve, the fresh air flowing through the throttle valve, and the natural gas injected into the mixture. The exhaust gas bypass valve 107 controls the boost pressure of the turbocharger.

[0043] Furthermore, the vehicle exhaust gas flow calculation device also includes a temperature and pressure sensor M1 on the throttle valve inlet side, a temperature and pressure sensor M2 at the middle position of the mixer, a temperature and pressure sensor M3 before the intake manifold, a temperature sensor T1 and a pressure sensor P1 before the EGR valve (EGR valve inlet side), a pressure sensor P2 after the EGR valve (EGR valve outlet side), and an oxygen concentration sensor L1 after the exhaust bypass valve.

[0044] In the technical solution provided by step S101 of the present invention, this is achieved by real-time acquisition of gas pressure data at both ends of the EGR valve and calculation of their ratio. Further, the inlet pressure value is obtained by a pressure sensor (P1) installed on the inlet side of the EGR valve, and the outlet pressure value is obtained by a pressure sensor (P2) installed on the outlet side of the EGR valve. The controller then performs a division operation on the two values ​​and outputs a real-time pressure ratio value.

[0045] The pressure ratio mentioned above refers to the ratio of the absolute gas pressures on both sides of the EGR valve inlet and outlet. Its physical meaning is used to characterize the degree to which the valve throttles the flow of exhaust gas, and it is a parameter for judging whether the gas is in a critical or subcritical flow state.

[0046] As an optional implementation, in the low-pressure EGR system, the EGR valve inlet pressure comes from the high-temperature and high-pressure exhaust gas in front of the turbocharger, and the outlet pressure is connected to the mixer inlet. At this time, P1 and P2 are collected by the turbine inlet pressure sensor and the mixer inlet pressure sensor, respectively, to reflect the driving force of the exhaust gas flowing from the exhaust side to the intake side.

[0047] As another optional implementation, in an EGR circuit with a cooler, the inlet pressure of the EGR valve is the pressure of the cooled medium-temperature high-pressure exhaust gas, and the outlet pressure is the pressure of the cooled gas before entering the mixer. At this time, the inlet pressure value and the outlet pressure value are obtained by pressure sensors of the cooler outlet and the pipeline after the EGR valve, respectively, to eliminate the interference of temperature changes on the pressure reading and ensure the physical accuracy of the pressure ratio calculation.

[0048] It is worth noting that by directly measuring the inlet and outlet pressures of the EGR valve and calculating the pressure ratio, the current flow state of the EGR valve can be quantified in real time. This avoids the cumulative errors caused by calculations based on indirect parameters (such as flow rate, opening degree, temperature, etc.), improves the response speed and data reliability of pressure ratio judgment, and provides accurate input basis for subsequent pressure ratio-based zoning control.

[0049] Step S102: Compare the pressure ratio value with the preset threshold to obtain the comparison result.

[0050] In the technical solution provided by step S102 of the present invention, the controller reads the calculated EGR valve pressure ratio value in real time and compares it with a pre-calibrated threshold s, outputting a binary judgment result (such as "greater than or equal to" or "less than"). Specifically, the controller retrieves the calibrated and stored threshold s from memory, which is the pressure ratio value corresponding to the critical point of the EGR valve flow state determined based on bench tests; then, the real-time pressure ratio value is logically judged with the threshold s, and a flag bit is output to distinguish whether the EGR valve is currently in the throttling sensitive zone.

[0051] The aforementioned preset threshold refers to the pressure ratio value corresponding to the inflection point of the EGR valve flow characteristic change determined by bench testing during engine calibration. Essentially, it reflects the physical boundary parameters of the gas transitioning from subcritical flow to critical flow, providing a basis for the system to achieve operating condition zoning.

[0052] As an optional implementation, under steady-state conditions, the pressure ratio value is collected at a frequency of 100Hz and the threshold s is set to 0.95. When the pressure ratio values ​​of three consecutive frames are all greater than or equal to 0.95, it is determined that the current area is in the throttling sensitive zone.

[0053] As another optional implementation, under transient conditions, the pressure ratio acquisition frequency is increased to 500Hz, and the threshold s is dynamically adjusted according to the engine speed and load. For example, under high load and high speed, s is adjusted from 0.95 to 0.98 to adapt to the critical pressure ratio drift caused by changes in gas density, thereby improving the environmental adaptability of the judgment.

[0054] It is worth noting that comparing the pressure ratio with a preset threshold enables a rapid and clear classification of the current flow state of the EGR valve. This allows the control system to accurately identify whether the valve is in a nonlinear sensitive range based on the pressure ratio, providing a direct trigger signal for switching between different calculation models and thus improving the real-time performance and determinism of the state identification.

[0055] In step S103, in response to the comparison result indicating that the pressure ratio is less than a preset threshold, the vehicle's exhaust flow rate is determined based on the vehicle's initial exhaust flow rate and correction coefficient.

[0056] In the technical solution provided by step S103 of the present invention, the initial exhaust gas flow rate corresponding to the current opening degree and pressure ratio of the EGR valve is retrieved by interpolation from the pre-stored EGR basic flow rate MAP table. Then, based on the gas temperature and pressure at the EGR valve inlet, the gas state correction coefficient is calculated, and the coefficient is multiplied by the initial exhaust gas flow rate to output the final EGR flow rate value.

[0057] The aforementioned initial exhaust gas flow rate refers to the theoretical flow rate value determined by the geometric characteristics, pressure ratio, and opening degree of the EGR valve under standard temperature and pressure conditions, derived from multidimensional MAP data calibrated on the bench.

[0058] The aforementioned correction factor refers to a dimensionless factor used to compensate for the density of the base flow rate based on the actual inlet gas temperature and pressure. It is calculated based on the ideal gas law and is used to eliminate the influence of gas density changes on flow rate estimation under non-standard operating conditions.

[0059] Specifically, the formula for calculating the vehicle's exhaust gas volume based on the vehicle's initial exhaust gas flow rate and correction factor is as follows:

[0060]

[0061] in, This represents the initial exhaust gas flow rate of the vehicle. For correction factor, This refers to the exhaust gas flow rate of the vehicle.

[0062] It is worth noting that, in response to the pressure ratio being less than the preset threshold, the exhaust gas flow rate is determined based on the initial exhaust gas flow rate and the correction coefficient. This enables real-time compensation for changes in the thermodynamic state of the gas in the throttling zone, avoiding flow rate estimation deviations caused by temperature and pressure fluctuations, and significantly improving the accuracy and environmental adaptability of exhaust gas flow rate calculation within this operating range.

[0063] Step S104: In response to the comparison result indicating that the pressure ratio is greater than or equal to a preset threshold, the exhaust gas flow rate of the vehicle is determined based on the flow rates of various types of gases flowing through the intake manifold of the vehicle, wherein the various types of gas flow rates include: mixed gas flow rate, air flow rate and natural gas flow rate.

[0064] In the technical solution provided by step S104 of the present invention, the total flow rate of the mixed gas flowing through the intake manifold is calculated by the intake manifold pressure sensor and the cylinder residual pressure model.

[0065] Furthermore, the fresh air flow rate through the throttle body is calculated using throttle opening, throttle inlet side rear pressure ratio, and temperature and pressure sensor data. Then, based on the excess air coefficient and fresh air flow rate, the natural gas flow rate injected into the intake manifold is calculated using the theoretical air-fuel ratio. Finally, the vehicle's exhaust gas flow rate is obtained by calculating the difference between these three values.

[0066] The above-mentioned mixed gas flow rate refers to the total mass flow rate of all gases entering the cylinder through the intake manifold, including air, exhaust gas, and natural gas.

[0067] The air flow rate mentioned above refers to the mass flow rate of fresh air entering the mixer through the throttle valve.

[0068] The aforementioned natural gas flow rate refers to the mass flow rate of natural gas injected into the intake manifold via the injector, and its value is determined by the closed-loop air-fuel ratio control.

[0069] Specifically, the formula for calculating the vehicle's exhaust gas flow rate based on the flow rates of various types of gases passing through the vehicle's intake manifold is as follows:

[0070]

[0071] in, This refers to the vehicle's exhaust gas flow rate. The flow rate of the mixed gas. For airflow, This refers to the flow rate of natural gas.

[0072] It is worth noting that when the pressure ratio is greater than or equal to the preset threshold, the exhaust gas flow rate is determined based on the difference between the mixed gas flow rate, air flow rate and natural gas flow rate. This can avoid the failure of the valve characteristic model in the nonlinear sensitive range of the exhaust gas valve, and directly use the measurable physical quantities of the intake system to realize the inversion calculation of the exhaust gas flow rate, which significantly improves the reliability and anti-interference ability of the flow rate estimation in this area.

[0073] From the above steps S101 to S104, it can be seen that in this invention, as... Figure 3 As shown, by acquiring the pressure ratio value of the vehicle's exhaust valve, where the pressure ratio is the ratio between the pressure value at the exhaust valve outlet and the pressure value at the exhaust valve inlet, and comparing the pressure ratio value with a preset threshold, a comparison result is obtained. This achieves the goal of determining the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient in response to the comparison result indicating that the pressure ratio value is less than the preset threshold. Furthermore, it achieves the technical effect of determining the vehicle's exhaust flow rate based on the flow rates of various types of gases flowing through the vehicle's intake manifold, in response to the comparison result indicating that the pressure ratio value is greater than or equal to the preset threshold. These various types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate. This can solve the technical problem in existing technologies where inaccurate calculation of vehicle exhaust flow rate leads to poor combustion stability in the vehicle engine.

[0074] The method described in this embodiment will now be described in further detail.

[0075] Step S201: Obtain the first preset pressure value, the first preset temperature value, and the temperature value at the inlet side of the exhaust valve;

[0076] Step S202: Determine the first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value;

[0077] Step S203: Determine the second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value;

[0078] Step S204: Determine the correction coefficient based on the first coefficient and the second coefficient.

[0079] In this embodiment, the first preset pressure value, the first preset temperature value, and the temperature value at the inlet side of the exhaust valve are obtained by the controller calling calibration parameters from non-volatile memory and reading sensor data in real time.

[0080] Specifically, the first preset pressure value is the standard pressure used for EGR flow model calibration, and the first preset temperature value is the standard temperature; both are fixed constants. The temperature value at the inlet side of the exhaust valve is collected in real time by a temperature sensor (T1) installed on the EGR valve inlet pipeline. The first coefficient is determined based on the pressure value at the exhaust valve inlet side and the aforementioned first preset pressure value by dividing the measured inlet pressure value by the preset standard pressure value. This first coefficient reflects the relative shift in gas density caused by changes in absolute pressure.

[0081] Furthermore, the second coefficient is determined based on the temperature value at the inlet side of the exhaust valve and the aforementioned first preset temperature value. This is obtained by dividing the preset standard temperature value by the measured inlet temperature value. The aforementioned second coefficient is used to reflect the reverse correction of gas density caused by thermal expansion.

[0082] Furthermore, the correction coefficient is determined based on the first coefficient and the second coefficient by multiplying the first coefficient by the second coefficient to obtain the final density correction coefficient. This coefficient is used to correct the initial flow rate value obtained from the table under standard operating conditions to the actual flow rate under actual operating conditions.

[0083] The aforementioned first preset pressure value and first preset temperature value refer to the reference standard conditions (usually 101.3 kPa and 293 K) on which the EGR basic flow MAP meter calibration is based, and are the benchmark points for flow model normalization.

[0084] The aforementioned correction factor is a dimensionless compensation factor calculated based on the density ratio of the actual gas state to the standard state, used to eliminate the interference of temperature and pressure fluctuations on flow rate estimation.

[0085] Specifically, the formula for calculating the correction factor is as follows:

[0086]

[0087] in, For correction factor, As the first coefficient, As the second coefficient, This refers to the pressure value at the inlet side of the exhaust valve. The first preset pressure value, This refers to the temperature value at the inlet side of the exhaust valve. This is the first preset temperature value.

[0088] It is worth noting that by obtaining measured values ​​of pressure and temperature and calculating correction coefficients based on standard conditions, direct compensation for changes in gas density at the exhaust valve inlet can be achieved, improving the output accuracy of the basic flow model under varying environmental and temperature conditions, ensuring that the flow estimation results are not affected by fluctuations in atmospheric pressure and exhaust gas temperature, and improving the physical consistency and stability of the calculation results.

[0089] Step S301: Obtain the opening value of the exhaust valve;

[0090] Step S302: Determine the initial exhaust gas flow rate based on the opening value and pressure ratio value.

[0091] In this embodiment, the opening value of the exhaust valve is obtained by the controller reading the duty cycle data of the angular displacement sensor or solenoid valve drive signal installed in the exhaust valve actuator in real time.

[0092] Optionally, the opening value of the exhaust valve can be expressed as a percentage or angle to represent the actual opening position of the EGR valve needle valve or butterfly plate, reflecting the real-time adjustment result of the control command on the flow area of ​​the valve port.

[0093] Furthermore, the initial exhaust gas flow rate of the vehicle is determined based on the above opening value and the above pressure ratio value by the controller using the current EGR valve opening and the pressure ratio (P2 / P1) before and after the EGR valve as two-dimensional input parameters, querying the pre-calibrated three-dimensional EGR basic flow rate MAP table, and interpolating to calculate the theoretical flow rate value corresponding to standard temperature and pressure conditions.

[0094] Optionally, the above-mentioned three-dimensional EGR basic flow MAP table is collected by bench tests, recording steady-state flow data under different combinations of opening degree and pressure ratio to form a nonlinear mapping relationship.

[0095] The opening value mentioned above refers to the digital expression of the actual opening degree of the EGR valve, in units of percentage or degree, and is a control input that reflects the change in the geometric flow area of ​​the valve.

[0096] The aforementioned initial exhaust gas flow rate refers to the theoretical flow rate value obtained by looking up a table based on the EGR valve opening and pressure ratio under standard temperature and pressure reference conditions. This value is a basic estimate without gas density correction and serves as the original input for subsequent correction calculations.

[0097] Specifically, the formula for calculating the initial exhaust gas flow rate is as follows:

[0098]

[0099] in, The initial exhaust gas flow rate, This represents the opening value of the exhaust valve. It is the ratio between the pressure value at the outlet side of the exhaust valve and the pressure value at the inlet side of the exhaust valve.

[0100] It is worth noting that by obtaining the exhaust valve opening value and pressure ratio value, and determining the initial exhaust gas flow rate based on the calibrated MAP table, the nonlinear mapping relationship between valve opening and flow rate can be established efficiently and accurately without relying on complex fluid dynamics models, significantly improving the response speed and data consistency of exhaust gas flow rate estimation under throttling conditions.

[0101] Step S401: Obtain the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, including the pressure-to-charge coefficient and the charge-to-flow coefficient.

[0102] Step S402: Determine the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients.

[0103] In this embodiment, the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients are obtained. Among them, the multiple calculation coefficients include the pressure-to-charge coefficient and the charge-to-flow coefficient. The above-mentioned multiple calculation coefficients are obtained by the controller reading the P_Map signal output by the absolute pressure sensor installed in the intake manifold in real time, and combining it with the lookup data stored in the engine control unit to obtain the residual gas pressure in the cylinder (gas pressure value in the cylinder), the pressure-to-charge coefficient, and the charge-to-flow coefficient.

[0104] Specifically, the intake manifold pressure value can be directly collected by sensors, reflecting the current pressure status of the intake system; the in-cylinder residual gas pressure is obtained from a two-dimensional MAP table based on the current engine speed and intake manifold pressure, and is used to characterize the back pressure effect of the residual exhaust gas from the previous cycle on the current intake process; the pressure-to-volume conversion factor is determined by the valve overlap angle and engine speed, and is obtained from a three-dimensional MAP table, its physical meaning being the efficiency factor of pressure difference driving gas into the cylinder; the volumetric efficiency conversion factor is obtained from a table based on engine displacement and speed, and is used to convert the volumetric charge into the mass flow rate per unit time.

[0105] Furthermore, the mixture flow rate is determined based on the intake manifold pressure value, the gas pressure value in the cylinder, and multiple calculation coefficients. This is achieved by using the difference between the intake manifold pressure and the residual gas pressure in the cylinder as the driving pressure difference, multiplying it by the pressure-to-charge coefficient and the charge-to-flow coefficient, to obtain the total gas mass flow rate flowing through the intake manifold into the cylinder per unit time.

[0106] It is worth noting that the above calculation process does not rely on direct flow sensors, but rather indirectly derives the total intake air volume through pressure gradient and engine structural parameters, thereby achieving real-time estimation of the total amount of mixed gas (including air, natural gas and exhaust gas) in the intake manifold.

[0107] The pressure-to-charge coefficient mentioned above is a dimensionless coefficient that reflects the efficiency of converting the pressure difference between the intake manifold and the cylinder into the volumetric volume of the cylinder. Its value is affected by the valve overlap angle and the speed, and is used to characterize the enhancing effect of the dynamic inertia of the airflow on the charging process.

[0108] The aforementioned charge-to-flow coefficient refers to the coefficient that converts the volumetric charge of a unit cylinder into the mass flow rate per unit time. Its value is positively correlated with the engine displacement and speed, and is used to realize the physical dimension conversion from volumetric flow rate to mass flow rate.

[0109] Specifically, the formula for calculating the flow rate of the mixed gas is as follows:

[0110]

[0111] in, The flow rate of the mixed gas. This refers to the pressure value in the intake manifold. This refers to the gas pressure value inside the cylinder. This is the pressure-to-charge coefficient. This is the volume-to-flow coefficient.

[0112] Specifically, the formula for determining the gas pressure value inside the cylinder is as follows:

[0113]

[0114] in, This refers to the gas pressure value inside the cylinder. This refers to the engine speed of the vehicle. This is the pressure value in the intake manifold.

[0115] It is worth noting that by acquiring the intake manifold pressure, in-cylinder residual pressure, and structural dependence coefficient, and calculating the mixed gas flow rate based on the product model, it is possible to achieve a high dynamic response estimation of the total gas mass in the intake manifold without adding a direct intake flow sensor, which significantly improves the estimation accuracy and adaptability of the total intake volume under throttling sensitive conditions.

[0116] Step S501: Obtain the engine valve opening value, engine speed, and engine displacement;

[0117] Step S502: Determine the pressure-to-charge coefficient based on the engine valve opening value and engine speed;

[0118] Step S503: Determine the charge-to-flow coefficient based on engine displacement and engine speed.

[0119] In this embodiment, the engine valve opening value, engine speed, and engine displacement are obtained by the controller reading feedback signals from the camshaft position sensor or valve actuator to obtain the current intake and exhaust valve overlap angles. Simultaneously, the real-time engine speed output from the crankshaft speed sensor is read, and the engine's fixed displacement parameters are retrieved from the controller's non-volatile memory.

[0120] Specifically, the valve opening value, in the form of valve overlap angle, represents the duration and degree of overlap of the simultaneous opening of the intake and exhaust valves, and is a dynamic parameter that affects the in-cylinder residual pressure and charging efficiency; the engine speed mentioned above is used to reflect the working cycle frequency; the engine displacement mentioned above is a fixed design parameter, representing the theoretical volume of a single cylinder or the whole engine.

[0121] Furthermore, the pressure-to-charge coefficient is determined based on the engine valve opening value and engine speed by using the valve overlap angle and engine speed as two-dimensional input parameters, querying the pre-calibrated pressure-to-charge coefficient MAP table, and interpolating to obtain the pressure-to-charge coefficient under the current operating condition.

[0122] Optionally, the above MAP table is constructed based on bench test data, measuring intake efficiency under different combinations of speed and valve overlap angle. Its value reflects the dynamic efficiency of differential pressure driving gas into the cylinder, which increases with the increase of valve overlap and speed to compensate for the gas inertial filling effect.

[0123] Furthermore, the charge-to-flow coefficient is determined based on engine displacement and engine speed by using the engine displacement and speed as input parameters in the controller, and then querying the charge-to-flow coefficient MAP table to obtain the charge-to-flow coefficient under the current operating conditions.

[0124] Optionally, the above MAP table is calibrated based on the engine geometry and the theoretical intake volume per unit speed, and is used to convert the intake volume per unit cycle into the mass flow rate per unit time. Its value increases linearly with the increase of displacement and speed.

[0125] The valve opening value mentioned above specifically refers to the overlapping angle of the intake and exhaust valves in this application. It is a dynamic parameter that characterizes the gas flow capacity during the simultaneous opening of the intake and exhaust valves, and directly affects the residual pressure in the cylinder and the charging efficiency.

[0126] The aforementioned pressure-to-charge coefficient refers to a dimensionless correction factor that converts the pressure difference between the intake manifold and the cylinder into an effective charge volume, reflecting the enhancing effect of valve timing and engine speed on the inertial charge of the gas.

[0127] The aforementioned charge-to-flow coefficient refers to the calibration coefficient that converts the unit circulating air volume into the mass flow rate per unit time. Its value is positively correlated with displacement and rotational speed, thus completing the physical dimension conversion from volume to mass flow rate.

[0128] Specifically, the formula for calculating the pressure-to-charge coefficient is as follows:

[0129]

[0130] in, This is the pressure-to-charge coefficient. This refers to the valve overlap angle of the engine. This refers to the engine speed of the vehicle.

[0131] Specifically, the formula for calculating the charge-to-flow coefficient is as follows:

[0132]

[0133] in, The charge-to-flow coefficient is the coefficient for volume conversion. Engine displacement. This refers to the engine speed of the vehicle.

[0134] It is worth noting that by obtaining the engine's valve overlap angle, engine speed, and engine displacement, and determining the pressure-to-charge coefficient and charge-to-flow coefficient based on the calibration MAP table, it is possible to accurately quantify the changes in intake dynamic characteristics with engine structure and operating state without relying on fluid dynamics modeling. This significantly improves the physical consistency and dynamic response accuracy of the pressure-driven mixed gas flow estimation model under different operating conditions.

[0135] Step S601: Obtain the second preset pressure value, the second preset temperature value, and the throttle opening value of the vehicle's throttle valve;

[0136] Step S602: Obtain the temperature value and pressure value at the throttle inlet side, and obtain the pressure value at the throttle outlet side.

[0137] Step S603: Determine the initial airflow based on the pressure value at the throttle inlet side, the pressure value at the throttle outlet side, and the throttle opening value;

[0138] Step S604: Determine the airflow rate based on the initial airflow rate, the temperature value at the throttle inlet side, the pressure value at the throttle inlet side, the second preset pressure value, and the second preset temperature value.

[0139] In this embodiment, the second preset pressure value, the second preset temperature value, and the throttle opening value of the vehicle are obtained by the controller reading the calibrated and fixed parameters from the non-volatile memory and receiving the opening signal from the throttle position sensor.

[0140] Specifically, the second preset pressure value is the standard atmospheric pressure on which the throttle flow characteristic calibration is based, and the second preset temperature value is the standard temperature on which the calibration is based. The two together constitute the reference operating conditions of the throttle flow MAP meter. The throttle opening value is collected in real time by a potentiometer or rotary transformer and is expressed as a percentage or angle to represent the degree of opening of the throttle orifice.

[0141] Furthermore, the temperature and pressure values ​​before the throttle valve, as well as the pressure value after the throttle valve, are obtained by using a temperature and pressure sensor (M1) installed at the front of the throttle valve and a temperature and pressure sensor (M2) installed at the mixer inlet to collect the absolute pressure (P3) and temperature (T3) at the throttle valve inlet and the absolute pressure (P4) at the throttle valve outlet, respectively.

[0142] Furthermore, the initial airflow is determined based on the pressure value before the throttle, the pressure value after the throttle, and the throttle opening value. This is done by using the pressure before the throttle, the pressure after the throttle, and the actual throttle opening as three-dimensional input parameters, querying a pre-calibrated throttle standard flow MAP table, and interpolating to obtain the theoretical airflow value corresponding to the standard conditions, which is recorded as the initial airflow.

[0143] Optionally, the aforementioned pre-calibrated throttle standard flow MAP table is obtained through bench calibration, recording the steady-state mass flow rate under different pressure ratios and opening combinations. Its essence is a mapping of the geometric flow characteristics of the throttle under ideal gas conditions.

[0144] Furthermore, the airflow rate is determined based on the initial airflow rate, the temperature value before the throttle, the pressure value before the throttle, the second preset pressure value, and the second preset temperature value. This is achieved by multiplying the initial airflow rate by pressure correction factors and temperature correction factors to obtain the actual airflow rate. This correction process, based on the ideal gas law, dynamically compensates for deviations of the actual intake air density from the calibration reference, outputting the actual fresh air mass flow rate passing through the throttle under the current operating conditions.

[0145] The aforementioned second preset pressure value and the aforementioned second preset temperature value refer to the reference base state (101.3 kPa, 293 K) on which the throttle standard flow characteristic MAP table is calibrated. Their function is to provide a unified normalized reference point for the flow model.

[0146] The aforementioned initial airflow rate refers to the theoretical mass flow rate obtained by looking up the table based on the throttle pressure ratio and opening degree under standard pressure and temperature conditions. The value does not take into account the influence of actual ambient temperature and pressure.

[0147] The air flow rate mentioned above refers to the real-time fresh air mass flow rate after actual temperature and pressure correction, providing accurate input for subsequent indirect calculation of exhaust gas flow rate.

[0148] Specifically, the formula for calculating airflow is as follows:

[0149]

[0150] in, For airflow, This is the pressure value at the throttle inlet side. This is the pressure value at the throttle outlet. This represents the current actual throttle opening value. The second preset pressure value, This is the second preset temperature value.

[0151] It is worth noting that by acquiring throttle opening, front and rear pressures and temperatures, and calculating the actual airflow based on the calibrated MAP and ideal gas correction model, high-precision dynamic modeling of throttle flow capacity can be achieved without adding an additional flow meter, significantly improving the accuracy and stability of fresh air volume estimation under different altitude, temperature and load conditions.

[0152] Step S701: Obtain the air-fuel ratio and excess air coefficient of natural gas;

[0153] Step S702: Determine the natural gas flow rate based on the air flow rate, the natural gas air-fuel ratio, and the excess air coefficient.

[0154] In this embodiment, the air-fuel ratio and excess air coefficient of natural gas are obtained by the controller reading the preset theoretical air-fuel ratio parameter (17.2:1) of natural gas from the non-volatile memory and combining it with the real-time excess air coefficient output by the excess air coefficient closed-loop control module under the current operating conditions.

[0155] Specifically, the air-fuel ratio of natural gas is the ratio of the theoretical air mass required for complete combustion of natural gas to the mass of natural gas. It is an inherent parameter of the stoichiometric characteristics of fuel and does not change with operating conditions. The excess air coefficient is the ratio of the actual fresh air mass entering the combustion chamber to the theoretically required air mass. It is dynamically calculated by PID control based on the feedback signal from the oxygen sensor and characterizes the richness or leanness of the mixture.

[0156] Furthermore, the natural gas flow rate is determined based on air flow rate, natural gas air-fuel ratio, and excess air coefficient. This is achieved by dividing the currently measured fresh air flow rate by the product of the theoretical air-fuel ratio and the excess air coefficient, thus calculating the natural gas mass flow rate. This calculation formula, based on stoichiometry, reverses the actual air flow rate to the corresponding natural gas supply based on the current mixture control target, achieving precise fuel quantity matching.

[0157] The aforementioned air-fuel ratio of natural gas refers to the ratio of the theoretical air mass to the fuel mass required for the complete combustion of natural gas. Its value is 17.2, which is a fixed chemical parameter determined by the compositional characteristics of natural gas.

[0158] The excess air coefficient mentioned above is the ratio of the actual air mass entering the combustion chamber to the theoretically required air mass. When the excess air coefficient is 1, it indicates stoichiometric combustion. When the excess air coefficient is greater than 1, it indicates lean combustion. When the excess air coefficient is less than 1, it indicates rich mixture combustion. Its value is dynamically adjusted by the exhaust oxygen concentration feedback closed-loop control and is used to characterize the actual air-fuel control target of the combustion system.

[0159] Specifically, the formula for calculating natural gas flow rate is as follows:

[0160]

[0161] in, For natural gas flow rate, For airflow, The excess air coefficient is set for the current operating conditions. Optionally, the value of 17.2 in the above formula is the pre-set theoretical air-fuel ratio of natural gas.

[0162] It is worth noting that by obtaining the natural gas air-fuel ratio and real-time excess air coefficient, and combining them with the measured air flow rate to calculate the natural gas flow rate, the fuel injection quantity can be dynamically estimated based on the combustion control target and air quantity without relying on a direct natural gas mass flow sensor. This significantly improves the response accuracy and closed-loop adaptability of natural gas supply estimation, and achieves stable control of the mixture concentration.

[0163] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or grid device, etc.) to execute the methods of the various embodiments of the present invention.

[0164] This embodiment also provides a device for determining vehicle exhaust gas flow rate, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0165] Figure 4This is a structural block diagram of a vehicle exhaust gas flow determination device 400 according to one embodiment of the present invention, as shown below. Figure 4 As shown, the device includes: a first acquisition module 41, a comparison module 42, a first determination module 43, and a second determination module 44.

[0166] The first acquisition module 41 is used to acquire the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side.

[0167] Comparison module 42 is used to compare the pressure ratio value with a preset threshold to obtain a comparison result;

[0168] The first determining module 43 is used to determine the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient in response to the comparison result indicating that the pressure ratio value is less than a preset threshold.

[0169] The second determining module 44 is used to determine the vehicle's exhaust gas flow rate based on the flow rates of various types of gases flowing through the vehicle's intake manifold in response to a comparison result indicating that the pressure ratio value is greater than or equal to a preset threshold. The various types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate.

[0170] Optionally, the vehicle exhaust gas flow determination device 400 further includes: a second acquisition module for acquiring a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust valve; a third determination module for determining a first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; a fourth determination module for determining a second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; and a fifth determination module for determining a correction coefficient based on the first coefficient and the second coefficient.

[0171] Optionally, the vehicle exhaust gas flow determination device 400 further includes: a third acquisition module for acquiring the opening value of the exhaust valve; and a sixth determination module for determining the initial exhaust gas flow rate based on the opening value and the pressure ratio value.

[0172] Optionally, the vehicle exhaust gas flow determination device 400 further includes: a fourth acquisition module for acquiring the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and a seventh determination module for determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0173] Optionally, the fourth acquisition module includes: an acquisition unit for acquiring the engine valve opening value, engine speed, and engine displacement; a first determination unit for determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and a second determination unit for determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0174] Optionally, the vehicle exhaust flow determination device 400 further includes: a fifth acquisition module for acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; a sixth acquisition module for acquiring a temperature value and a pressure value at the throttle valve inlet side, and a pressure value at the throttle valve outlet side; an eighth determination module for determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and a ninth determination module for determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0175] Optionally, the vehicle exhaust flow determination device 400 further includes: a sixth acquisition module for acquiring the natural gas air-fuel ratio and the excess air coefficient; and a tenth determination module for determining the natural gas flow rate based on the air flow rate, the natural gas air-fuel ratio, and the excess air coefficient.

[0176] Embodiments of the present invention also provide a vehicle, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the above-described method for determining vehicle exhaust gas flow.

[0177] Optionally, in this embodiment, the vehicle may be configured to store a computer program for performing the following steps:

[0178] Step S101: Obtain the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side.

[0179] Step S102: Compare the pressure ratio value with the preset threshold to obtain the comparison result;

[0180] Step S103: In response to the comparison result indicating that the pressure ratio is less than a preset threshold, determine the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient.

[0181] Step S104: In response to the comparison result indicating that the pressure ratio is greater than or equal to a preset threshold, the exhaust gas flow rate of the vehicle is determined based on the flow rates of various types of gases flowing through the intake manifold of the vehicle, wherein the various types of gas flow rates include: mixed gas flow rate, air flow rate and natural gas flow rate.

[0182] Optionally, when the processor executes the program, it also performs the following steps: obtaining a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust valve; determining a first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; determining a second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; and determining a correction coefficient based on the first coefficient and the second coefficient.

[0183] Optionally, the processor may also perform the following steps when executing the program: obtaining the opening value of the exhaust valve; and determining the initial exhaust flow rate based on the opening value and the pressure ratio value.

[0184] Optionally, when the processor executes the program, it also performs the following steps: obtaining the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0185] Optionally, the processor may also perform the following steps when executing the program: obtaining the engine valve opening value, engine speed, and engine displacement; determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0186] Optionally, the processor, when executing the program, further implements the following steps: acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; acquiring a temperature value and a pressure value at the throttle valve inlet side, and acquiring a pressure value at the throttle valve outlet side; determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0187] Optionally, the processor may also perform the following steps when executing the program: obtaining the air-fuel ratio and excess air coefficient of natural gas; and determining the natural gas flow rate based on the air flow rate, the air-fuel ratio, and the excess air coefficient.

[0188] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0189] Embodiments of the present invention also provide an electronic device, such as... Figure 5 As shown, it includes a memory 51 and a processor 52, wherein the memory stores a computer program and the processor is configured to run the computer program to execute the above-described method for determining the vehicle exhaust gas flow rate.

[0190] Optionally, in this embodiment, the electronic device may be configured to store a computer program for performing the following steps:

[0191] Step S101: Obtain the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side.

[0192] Step S102: Compare the pressure ratio value with the preset threshold to obtain the comparison result;

[0193] Step S103: In response to the comparison result indicating that the pressure ratio is less than a preset threshold, determine the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient.

[0194] Step S104: In response to the comparison result indicating that the pressure ratio is greater than or equal to a preset threshold, the exhaust gas flow rate of the vehicle is determined based on the flow rates of various types of gases flowing through the intake manifold of the vehicle, wherein the various types of gas flow rates include: mixed gas flow rate, air flow rate and natural gas flow rate.

[0195] Optionally, when the processor executes the program, it also performs the following steps: obtaining a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust valve; determining a first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; determining a second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; and determining a correction coefficient based on the first coefficient and the second coefficient.

[0196] Optionally, the processor may also perform the following steps when executing the program: obtaining the opening value of the exhaust valve; and determining the initial exhaust flow rate based on the opening value and the pressure ratio value.

[0197] Optionally, when the processor executes the program, it also performs the following steps: obtaining the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0198] Optionally, the processor may also perform the following steps when executing the program: obtaining the engine valve opening value, engine speed, and engine displacement; determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0199] Optionally, the processor, when executing the program, further implements the following steps: acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; acquiring a temperature value and a pressure value at the throttle valve inlet side, and acquiring a pressure value at the throttle valve outlet side; determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0200] Optionally, the processor may also perform the following steps when executing the program: obtaining the air-fuel ratio and excess air coefficient of natural gas; and determining the natural gas flow rate based on the air flow rate, the air-fuel ratio, and the excess air coefficient.

[0201] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0202] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program configured to execute the above-described method for determining vehicle exhaust gas flow rate when run on a computer or processor.

[0203] Optionally, in this embodiment, the computer-readable storage medium may be configured to store a computer program for performing the following steps:

[0204] Step S101: Obtain the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side.

[0205] Step S102: Compare the pressure ratio value with the preset threshold to obtain the comparison result;

[0206] Step S103: In response to the comparison result indicating that the pressure ratio is less than a preset threshold, determine the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient.

[0207] Step S104: In response to the comparison result indicating that the pressure ratio is greater than or equal to a preset threshold, the exhaust gas flow rate of the vehicle is determined based on the flow rates of various types of gases flowing through the intake manifold of the vehicle, wherein the various types of gas flow rates include: mixed gas flow rate, air flow rate and natural gas flow rate.

[0208] Optionally, the storage medium is configured to store program code for performing the following steps: obtaining a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust valve; determining a first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; determining a second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; and determining a correction coefficient based on the first coefficient and the second coefficient.

[0209] Optionally, the storage medium is configured to store program code for performing the following steps: obtaining the opening value of the exhaust valve; and determining the initial exhaust flow rate based on the opening value and the pressure ratio.

[0210] Optionally, the storage medium is configured to store program code for performing the following steps: obtaining the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0211] Optionally, the storage medium is configured to store program code for performing the following steps: obtaining the engine valve opening value, engine speed, and engine displacement; determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0212] Optionally, the storage medium is configured to store program code for performing the following steps: acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; acquiring a temperature value and a pressure value at the throttle valve inlet side, and acquiring a pressure value at the throttle valve outlet side; determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0213] Optionally, the storage medium is configured to store program code for performing the following steps: obtaining the natural gas air-fuel ratio and excess air coefficient; determining the natural gas flow rate based on the air flow rate, the natural gas air-fuel ratio, and the excess air coefficient.

[0214] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0215] Embodiments of the present invention also provide a computer program product, including a computer program, wherein the computer program, when executed by a processor, implements the steps of the above-described method for determining vehicle exhaust gas flow.

[0216] Optionally, in this embodiment, the computer program product described above may be configured to store a computer program for performing the following steps:

[0217] Step S101: Obtain the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side.

[0218] Step S102: Compare the pressure ratio value with the preset threshold to obtain the comparison result;

[0219] Step S103: In response to the comparison result indicating that the pressure ratio is less than a preset threshold, determine the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and correction coefficient.

[0220] Step S104: In response to the comparison result indicating that the pressure ratio is greater than or equal to a preset threshold, the exhaust gas flow rate of the vehicle is determined based on the flow rates of various types of gases flowing through the intake manifold of the vehicle, wherein the various types of gas flow rates include: mixed gas flow rate, air flow rate and natural gas flow rate.

[0221] Optionally, when the computer program executes the program, it also performs the following steps: obtaining a first preset pressure value, a first preset temperature value, and a temperature value at the inlet side of the exhaust valve; determining a first coefficient based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; determining a second coefficient based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; and determining a correction coefficient based on the first coefficient and the second coefficient.

[0222] Optionally, the computer program may also perform the following steps when executing the program: obtaining the opening value of the exhaust valve; and determining the initial exhaust flow rate based on the opening value and the pressure ratio value.

[0223] Optionally, when the computer program executes the program, it also performs the following steps: obtaining the pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients, wherein the multiple calculation coefficients include a pressure-to-charge coefficient and a charge-to-flow coefficient; and determining the mixed gas flow rate based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the multiple calculation coefficients.

[0224] Optionally, the computer program may also perform the following steps when executing the program: obtaining the engine valve opening value, engine speed and engine displacement; determining the pressure-to-charge coefficient based on the engine valve opening value and engine speed; and determining the charge-to-flow coefficient based on the engine displacement and engine speed.

[0225] Optionally, the computer program may further perform the following steps when executing the program: acquiring a second preset pressure value, a second preset temperature value, and a throttle opening value of the vehicle's throttle valve; acquiring a temperature value and a pressure value at the throttle valve inlet side, and acquiring a pressure value at the throttle valve outlet side; determining an initial airflow rate based on the pressure value at the throttle valve inlet side, the pressure value at the throttle valve outlet side, and the throttle opening value; and determining the airflow rate based on the initial airflow rate, the temperature value at the throttle valve inlet side, the pressure value at the throttle valve inlet side, the second preset pressure value, and the second preset temperature value.

[0226] Optionally, the computer program may also perform the following steps when executing the program: obtaining the air-fuel ratio and excess air coefficient of natural gas; and determining the natural gas flow rate based on the air flow rate, the air-fuel ratio and the excess air coefficient of natural gas.

[0227] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0228] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0229] In the embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0230] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0231] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0232] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or grid device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0233] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for determining the exhaust gas volume of a vehicle, characterized in that, include: Obtain the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value at the exhaust valve outlet side and the pressure value at the exhaust valve inlet side; The pressure ratio value is compared with a preset threshold to obtain a comparison result; In response to the comparison result indicating that the pressure ratio is less than the preset threshold, the exhaust flow rate of the vehicle is determined based on the initial exhaust flow rate of the vehicle and the correction coefficient. In response to the comparison result indicating that the pressure ratio is greater than or equal to the preset threshold, the exhaust gas flow rate of the vehicle is determined based on the flow rates of various types of gases flowing through the intake manifold of the vehicle, wherein the various types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate.

2. The method for determining vehicle exhaust gas volume according to claim 1, characterized in that, The method further includes: Obtain the first preset pressure value, the first preset temperature value, and the temperature value at the inlet side of the exhaust gas valve; A first coefficient is determined based on the pressure value at the inlet side of the exhaust valve and the first preset pressure value; The second coefficient is determined based on the temperature value at the inlet side of the exhaust valve and the first preset temperature value; The correction coefficient is determined based on the first coefficient and the second coefficient.

3. The method for determining vehicle exhaust gas volume according to claim 1, characterized in that, The method further includes: Obtain the opening value of the exhaust valve; The initial exhaust gas flow rate is determined based on the opening value and the pressure ratio value.

4. The method for determining vehicle exhaust gas volume according to claim 1, characterized in that, The method further includes: The pressure value of the intake manifold, the gas pressure value in the cylinder, and multiple calculation coefficients are obtained, wherein the multiple calculation coefficients include the pressure-to-charge coefficient and the charge-to-flow coefficient. The flow rate of the mixed gas is determined based on the pressure value of the intake manifold, the gas pressure value in the cylinder, and the plurality of calculation coefficients.

5. The method for determining vehicle exhaust gas volume according to claim 4, characterized in that, Obtaining the plurality of calculated coefficients includes: Obtain the engine valve opening value, engine speed, and engine displacement; The pressure-to-charge coefficient is determined based on the opening value of the engine valve and the engine speed. The charge-to-flow coefficient is determined based on the engine displacement and the engine speed.

6. The method for determining vehicle exhaust gas volume according to claim 1, characterized in that, The method further includes: The second preset pressure value, the second preset temperature value, and the opening value of the throttle valve of the vehicle are obtained. The temperature value and pressure value at the throttle inlet side are obtained, and the pressure value at the throttle outlet side is obtained. The initial airflow is determined based on the pressure value at the throttle inlet side, the pressure value at the throttle outlet side, and the throttle opening value. The airflow rate is determined based on the initial airflow rate, the temperature value at the throttle inlet side, the pressure value at the throttle inlet side, the second preset pressure value, and the second preset temperature value.

7. The method for determining vehicle exhaust gas volume according to claim 1, characterized in that, The method further includes: To obtain the air-fuel ratio and excess air coefficient of natural gas; The natural gas flow rate is determined based on the air flow rate, the natural gas air-fuel ratio, and the excess air coefficient.

8. A device for determining the exhaust gas flow rate of a vehicle, characterized in that, include: The first acquisition module is used to acquire the pressure ratio value of the vehicle's exhaust valve, wherein the pressure ratio value is the ratio between the pressure value on the exhaust valve outlet side and the pressure value on the exhaust valve inlet side. The comparison module is used to compare the pressure ratio value with a preset threshold to obtain a comparison result; The first determining module is used to determine the vehicle's exhaust flow rate based on the vehicle's initial exhaust flow rate and a correction coefficient in response to the comparison result indicating that the pressure ratio value is less than the preset threshold. The second determining module is used to determine the exhaust gas flow rate of the vehicle based on the multiple types of gas flow rates flowing through the intake manifold of the vehicle, in response to the comparison result indicating that the pressure ratio value is greater than or equal to the preset threshold. The multiple types of gas flow rates include: mixed gas flow rate, air flow rate, and natural gas flow rate.

9. A vehicle comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method for determining vehicle exhaust gas volume as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program is configured to execute, when run on a computer or processor, the method for determining the vehicle exhaust gas volume as described in any one of claims 1 to 7.

Images