Method and device for estimating residual waste gas in cylinder of hydrogen-fired range extender, vehicle and medium

Abstract

The invention discloses a method and device for estimating residual waste gas in a cylinder of a hydrogen combustion range extender, a vehicle and a medium, and relates to the technical field of vehicle engines, and the method comprises the steps: building a waste gas flow model at an exhaust valve based on engine structure parameters, a pressure signal and a temperature signal of an exhaust manifold, and exhaust efficiency; on the basis of the inlet waste gas flow of the exhaust manifold and the outlet waste gas flow of the exhaust manifold, according to the mass conservation relation and the ideal gas state equation, an exhaust pressure average value discrete dynamic model of the exhaust manifold is built; constructing a self-adaptive observer based on an exhaust pressure average discrete dynamic model, and estimating the exhaust efficiency; according to the online estimation result of the exhaust efficiency, the mass of exhaust gas exhausted in each cycle is obtained, and the amount of residual exhaust gas in the cylinder is calculated. By adopting the method, the mass of exhaust gas in each cycle and the amount of residual exhaust gas in the cylinder can be accurately estimated in real time in the actual vehicle running process, so that reliable reference is provided for combustion control and emission optimization.

Description

Technical Field

[0001] This invention relates to the field of vehicle engine technology, and in particular to a method, apparatus, vehicle, and medium for estimating in-cylinder residual exhaust gas in a hydrogen-fueled range extender. Background Technology

[0002] Driven by the goals of carbon peaking and carbon neutrality, the transportation sector is actively transforming towards low-carbon and zero-emission directions. Hydrogen fuel, with its advantages of being clean, renewable, and having low greenhouse gas emissions, is considered a crucial energy source for future transportation equipment. In particular, the opposed-piston two-stroke hydrogen internal combustion engine used in range extenders of hybrid vehicles is seen as a promising new power system. However, in such engines, the accuracy of estimating the amount of residual exhaust gas in the cylinder directly affects the combustion control stability of the range extender and the overall vehicle performance, thus placing higher demands on the real-time performance and accuracy of the electronic control system.

[0003] In related technologies, some solutions rely on constructing complex engine models and performing multiple numerical simulations to obtain the variation patterns of residual exhaust gas in the cylinder. The results are then analyzed through simulation. However, such methods are mainly applicable to the development stage and lack adaptability to actual operating conditions, making them difficult to apply in real-time to vehicle control systems. Other solutions calculate the partial pressure of residual exhaust gas based on cyclic exhaust back pressure, but attributing the mass of residual exhaust gas solely to exhaust back pressure fails to fully consider changes in in-cylinder combustion effects during actual vehicle operation, making the calculation results difficult to accurately reflect actual operating conditions. Still other methods estimate the flow rate based on valve flow models at different crankshaft angles, but these methods heavily rely on extensive prior calibration data, resulting in a large calibration workload and difficulty in adapting to new vehicle models, thus limiting their widespread application in practical engineering.

[0004] In summary, the relevant technologies generally suffer from poor adaptability, insufficient real-time performance, or high dependence on calibration, and cannot meet the requirements of hydrogen-fueled range extenders for high-precision online estimation of in-cylinder residual exhaust gas. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the object of this invention is to provide a method, apparatus, vehicle, and medium for estimating in-cylinder residual exhaust gas in a hydrogen-powered range extender, so as to improve the real-time performance and adaptability of in-cylinder residual exhaust gas estimation, and enhance the accuracy of engine combustion control and vehicle energy management.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for estimating in-cylinder residual exhaust gas in a hydrogen-fueled range extender, comprising: Based on engine structural parameters, pressure and temperature signals from the exhaust manifold, and exhaust efficiency, an exhaust gas flow model at the exhaust valve is constructed; the exhaust efficiency is a time-varying parameter to be identified. Based on the inlet exhaust gas flow rate and outlet exhaust gas flow rate of the exhaust manifold, and according to the mass conservation relationship and the ideal gas law, a discrete dynamic model of the average exhaust pressure of the exhaust manifold is constructed; wherein, the inlet exhaust gas flow rate of the exhaust manifold is determined by the exhaust gas flow rate model of the exhaust valve, and the outlet exhaust gas flow rate of the exhaust manifold is obtained by the flow sensor. An adaptive observer is constructed based on the discrete dynamic model of the average exhaust pressure, and the exhaust efficiency is estimated by the adaptive observer. Based on the online estimation results of the exhaust efficiency, the mass of exhaust gas discharged per cycle is obtained and the amount of residual exhaust gas in the cylinder is calculated.

[0007] In addition, the method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, estimating the exhaust efficiency using the adaptive observer includes... Update the state vector of the adaptive observer based on the current exhaust manifold pressure signal, outlet exhaust gas flow rate and exhaust manifold volume; Using the updated state vector and the discrete dynamic model of the average exhaust pressure, the exhaust efficiency is estimated on the ground to obtain the real-time estimate of the exhaust efficiency.

[0008] According to one embodiment of the present invention, during the process of updating the state vector, a gain matrix is ​​introduced to adjust the update magnitude of the state vector.

[0009] According to one embodiment of the present invention, dynamic compensation parameters and structural constraint parameters are introduced during the process of updating the observer state vector; The state vector update is corrected based on the dynamic compensation parameters and the structural constraint parameters.

[0010] According to one embodiment of the present invention, the following features are provided: The exhaust pressure predicted by the adaptive observer based on the state vector of the previous time step and the discrete dynamic model of the average exhaust pressure is compared with the current exhaust manifold pressure signal to obtain the exhaust pressure estimation error. The state vector of the adaptive observer is corrected based on the exhaust pressure estimation error.

[0011] According to one embodiment of the present invention, obtaining the mass of exhaust gas discharged in each cycle includes: Based on the online estimation results of the exhaust efficiency, the exhaust gas mass flow rate at the exhaust valve is calculated; The exhaust gas mass flow rate at the exhaust valve is integrated within each working cycle to obtain the exhaust gas mass discharged from the cylinder in each cycle.

[0012] According to one embodiment of the present invention, calculating the residual exhaust gas volume in the cylinder includes: Based on the law of conservation of mass, the amount of residual exhaust gas in the cylinder is calculated using the mass of exhaust gas discharged from the cylinder, the mass of intake air, and the mass of fuel entering the cylinder in each cycle.

[0013] To achieve the above objectives, a second aspect of the present invention provides a device for estimating in-cylinder residual exhaust gas in a hydrogen-fueled range extender, comprising: The exhaust gas flow model construction module is used to construct an exhaust gas flow model at the exhaust valve based on engine structural parameters, pressure and temperature signals from the exhaust manifold, and exhaust efficiency; the exhaust efficiency is a time-varying parameter to be identified. The module for constructing a discrete dynamic model of the average exhaust pressure is used to construct a discrete dynamic model of the average exhaust pressure of the exhaust manifold based on the inlet exhaust gas flow rate and the outlet exhaust gas flow rate of the exhaust manifold, and according to the mass conservation relationship and the ideal gas law. The inlet exhaust gas flow rate of the exhaust manifold is determined by the exhaust gas flow rate model of the exhaust valve, and the outlet exhaust gas flow rate of the exhaust manifold is obtained by the flow sensor. An adaptive observer estimation module is used to construct an adaptive observer based on the discrete dynamic model of the average exhaust pressure, and to estimate the exhaust efficiency through the adaptive observer. The residual exhaust gas volume calculation module is used to obtain the mass of exhaust gas discharged in each cycle and calculate the residual exhaust gas volume in the cylinder based on the online estimation result of the exhaust efficiency.

[0014] To achieve the above objectives, a third aspect of the present invention provides a vehicle including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method for estimating residual exhaust gas in the cylinder of a hydrogen-powered range extender.

[0015] To achieve the above objectives, a fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the steps of the above-described method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender.

[0016] This invention discloses a method, apparatus, vehicle, and medium for estimating in-cylinder residual exhaust gas in a hydrogen-powered range extender. It constructs an exhaust gas flow model at the exhaust valve based on engine structural parameters and pressure and temperature signals from the exhaust and intake manifolds. Furthermore, it establishes a discrete dynamic model of the average exhaust pressure by combining the mass conservation relationship between the inlet and outlet flow rates of the exhaust manifold. This model reflects the exhaust flow and pressure changes under actual operating conditions. Based on this, an adaptive observer is further constructed to achieve real-time estimation of exhaust efficiency, enabling the algorithm to automatically adjust parameters according to changes in engine operating conditions, avoiding reliance on large amounts of calibration data. Through the above design, this invention can accurately and stably estimate in-cylinder residual exhaust gas during actual vehicle operation, improving the accuracy of range extender combustion control, enhancing the adaptability of the vehicle's powertrain to complex operating conditions, and providing reliable support for efficient control of the hydrogen-powered range extender and overall vehicle energy management. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the cylinder structure of a two-stroke hydrogen internal combustion engine in one embodiment; Figure 2 This is a flowchart illustrating a method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender in one embodiment. Figure 3 Here is a block diagram of the adaptive observer in one embodiment; Figure 4 This is a schematic diagram of the execution flow for calculating residual exhaust gas in one embodiment; Figure 5 This is a structural block diagram of an in-cylinder residual exhaust gas estimation device for a hydrogen-fueled range extender in one embodiment. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] The implementation details of the technical solutions in the embodiments of this application are described in detail below.

[0020] Figure 1 A schematic diagram of the cylinder structure of a two-stroke hydrogen internal combustion engine is shown. Its structural features can be used to clarify the gas flow relationship near the intake and exhaust valves. The pressure and temperature within the intake manifold are defined as follows: and The pressure and temperature inside the exhaust manifold are respectively and The gas mass flow rates at the intake and exhaust valves are and The mass flow rate of the gas at the exhaust manifold outlet is .

[0021] The following is based on Figure 1 Taking the structural relationships and physical quantity definitions shown as examples, the specific process of estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender is explained.

[0022] In one embodiment, such as Figure 2 The diagram shows a flowchart illustrating a method for estimating in-cylinder residual exhaust gas in a hydrogen-powered range extender. This method may include the following steps: Step S101: Based on engine structural parameters, pressure and temperature signals of the exhaust manifold, and exhaust efficiency, construct an exhaust gas flow model at the exhaust valve.

[0023] During model building, basic parameters related to the scavenging process, including engine displacement, are obtained based on the engine's geometry. and rotational speed These parameters together determine the periodic discharge volume of gas in the cylinder and the basic flow environment near the exhaust valve.

[0024] Reference Figure 1 As shown, pressure and temperature signals can be acquired in real time through pressure and temperature sensors on the exhaust manifold. The pressure and temperature inside the exhaust manifold reflect the back pressure environment faced by the exhaust gas, and these state variables directly affect the specific magnitude of the exhaust mass flow rate.

[0025] The gas mass flow rate at the exhaust valve is driven by the pressure difference across the exhaust valve and is simultaneously influenced by factors such as the exhaust valve opening area, valve phase, the amount of combustion products in the cylinder, exhaust manifold back pressure, and the current engine operating conditions. To accurately describe the dynamic deviation of the actual exhaust volume from the ideal exhaust volume, exhaust efficiency is introduced as a time-varying parameter. Here, exhaust efficiency is defined as... This is the ratio of the actual amount of exhaust gas discharged from the cylinder during the exhaust process to the theoretical amount of exhaust gas. This parameter is used to describe the fluctuation in the actual exhaust volume caused by changes in valve flow characteristics, combustion state, and the proportion of residual gas in the cylinder during the exhaust process.

[0026] Based on this, according to the exhaust manifold pressure and temperature and engine structural parameters, a mass flow rate relationship reflecting the gas flow behavior at the exhaust valve can be established, thereby obtaining a physical model of the exhaust gas mass flow rate at the exhaust valve. The exhaust gas flow rate model at the exhaust valve is specifically expressed as follows:

[0027] in, The exhaust efficiency contained in the formula can dynamically compensate for the difference in exhaust volume caused by the actual combustion conditions in the cylinder, the fluctuation of exhaust back pressure and the changes in the flow characteristics of the exhaust valve, so that the model can accurately reflect the instantaneous exhaust gas flow at the exhaust valve under different operating conditions.

[0028] Step S102: Based on the inlet exhaust gas flow rate and outlet exhaust gas flow rate of the exhaust manifold, and according to the mass conservation relationship and the ideal gas law, construct a discrete dynamic model of the average exhaust pressure of the exhaust manifold.

[0029] The exhaust manifold is considered a pipe structure with a fixed volume. The internal exhaust gas pressure changes with the difference between the gas inflow and outflow per unit time. Therefore, the principle of mass conservation is used to describe the dynamic change law of exhaust gas mass in the manifold.

[0030] The rate of change of gas mass within the exhaust manifold is determined by the difference between the inlet exhaust gas flow rate and the outlet exhaust gas flow rate. The inlet exhaust gas flow rate is determined by the exhaust gas flow model at the exhaust valve, while the outlet exhaust gas flow rate is measured by a flow sensor installed at the exhaust manifold outlet. To establish a quantitative relationship between the change in gas mass and the change in exhaust manifold pressure, the ideal gas law is introduced. The functional relationship between the pressure, volume, temperature, and mass of the gas within the manifold is used to derive the dynamic change in exhaust pressure. Given the exhaust manifold volume... Temperature signal and sampling step size Under certain conditions, the continuous form of the exhaust pressure dynamic equation can be discretized, making the model applicable to the periodic sampling process of actual engine control systems.

[0031] Based on this, a discrete dynamic model of the exhaust manifold mean pressure can be constructed, specifically expressed as:

[0032] in, This represents the average pressure in the exhaust manifold during the current sampling period; For exhaust efficiency; The exhaust gas mass flow rate at the exhaust manifold outlet is measured by a flow sensor. This model reflects the dynamic changes in pressure inside the exhaust manifold as a function of engine operating conditions and the scavenging process.

[0033] Step S103: Construct an adaptive observer based on a discrete dynamic model of average exhaust pressure, and estimate exhaust efficiency using the adaptive observer.

[0034] After establishing the exhaust pressure average value model, an adaptive observer is further constructed to achieve dynamic tracking and estimation of exhaust efficiency. This observer, based on a discrete dynamic model of exhaust pressure, uses a recursive approach to jointly estimate the exhaust pressure state and exhaust efficiency, thereby enabling real-time updates of exhaust efficiency as the engine operates. The design goal of the adaptive observer is to enable dynamic updates of exhaust efficiency with changes in engine operating conditions and to maintain good estimation stability even when the model exhibits nonlinear disturbances or environmental uncertainties.

[0035] Figure 3 This is a block diagram of the adaptive observer. The modules and signal flow in the diagram can intuitively reflect the processes of state vector update, error correction, and exhaust efficiency estimation. The core of the observer is the recursive equation module at the top, which uses the state vector from the previous time step and the current engine speed at each sampling time. and exhaust manifold real-time pressure The updated state vector is calculated. This vector contains the exhaust pressure state and related estimates.

[0036] The exhaust pressure estimation module is given a state vector Based on the predicted pressure Real-time pressure and pressure estimation error Simultaneously, the gas mass flow rate at the exhaust manifold outlet is introduced. and engine speed This corrects the predicted pressure. Pressure estimation error. Predicted pressure With real-time pressure The difference is calculated, and this error signal is used to correct the current pressure estimate on the one hand, and on the other hand, it is sent as a feedback quantity to the recursive equation module and subsequent modules, thereby continuously correcting and updating the state vector.

[0037] The updated state vector and pressure estimation error are fed into the exhaust efficiency estimation module. This module is based on... , And related inputs, online estimation of exhaust efficiency. .

[0038] The velocity density model module located at the bottom is , and Input: Real-time estimated value of exhaust gas mass flow rate at the exhaust valve. This enables real-time estimation of exhaust flow rate.

[0039] The following is combined with Figure 3The process of the adaptive observer estimating exhaust efficiency is described in detail with different embodiments.

[0040] In one embodiment, the real-time pressure signal of the exhaust manifold, along with the outlet exhaust gas flow rate and the volume of the exhaust manifold, are acquired as inputs to the adaptive observer. Using these input parameters and the observer's state vector from the previous time step, the state vector is updated according to a discrete dynamic model based on the average exhaust pressure. The state vector update process includes predicting the exhaust pressure state and correcting prediction errors using pressure measurements, thereby providing fundamental information for estimating exhaust efficiency at the next time step.

[0041] By combining the updated state vector with the discrete dynamic model of the average exhaust pressure, exhaust efficiency can be estimated online, yielding real-time estimates. These estimates describe the change in actual exhaust gas volume at the exhaust valve relative to the theoretical value, ensuring that exhaust efficiency dynamically adjusts with engine operating conditions and reflects the impact of operating condition changes on exhaust emissions in real time.

[0042] In a practical implementation, the recursive equation of the adaptive observer can be expressed as:

[0043]

[0044]

[0045]

[0046] in, This represents the observer state vector, which includes the exhaust pressure state and related estimates; This is the sampling step size; and These are the engine displacement and engine speed, respectively. This refers to the exhaust manifold volume; This refers to the current pressure in the exhaust manifold. To predict stress; This is an estimate of the exhaust efficiency; This represents the pressure estimation error; , , , , Parameters are designed for the observer to ensure the convergence of state and efficiency estimates.

[0047] In the above expressions, the first formula is used for the prediction update of the observer's state vector, which is corrected by combining the linear state transfer model and the observation gain; the second formula is used for the recursive update of the exhaust pressure, which combines the model prediction, the actual measured pressure error, and the exhaust efficiency estimate to achieve pressure prediction correction; the third formula is used for the recursive estimation of exhaust efficiency, which guides the online update of efficiency through the observation error, and achieves dynamic convergence of exhaust efficiency with operating conditions; the fourth formula is used to calculate the exhaust gas mass flow rate at the exhaust valve based on the estimated pressure and efficiency, which incorporates the estimated pressure and efficiency from the adaptive observer. and The exhaust gas flow rate model was obtained by substituting it into the exhaust valve.

[0048] In one embodiment, a gain matrix is ​​introduced during the process of updating the adaptive observer state vector. This gain matrix is ​​used to adjust the update magnitude of the state vector. Based on the deviation between the predicted pressure from the discrete dynamic model of the average exhaust pressure and the actual measured pressure, the step size of the state vector update is adjusted, ensuring that changes in the state variables can respond quickly to changes in exhaust pressure while avoiding excessive oscillations. The gain matrix design must meet the observer convergence requirements to ensure that the state vector stably approaches the true value over time.

[0049] In practical applications, to ensure the convergence of exhaust efficiency estimation, the design of the gain matrix K must satisfy the following conditions: For a given system matrix and If the observer gain satisfy Then the exhaust efficiency will converge steadily over time, eventually .

[0050] In one embodiment, a dynamic compensation parameter is introduced during the process of updating the observer state vector. and structural constraint parameters The system is used to correct the update of the state vector. The dynamic compensation parameter is used to adjust the state vector update in real time according to changes in the system state, enabling the observer to adapt to fluctuations in engine operating conditions; the structural constraint parameter is used to constrain the update amplitude of the state vector, maintaining the stability and convergence of the observer.

[0051] The state vector is predicted based on the discrete dynamic model of the average exhaust pressure, and then the dynamic compensation parameters introduced in the observer recursion are used. and structural constraint parameters The prediction error is corrected, thereby enabling dynamic adjustment of the state vector.

[0052] It should be noted that the dynamic compensation parameters and structural constraint parameters The value of needs to be determined through convergence analysis and adjusted according to actual working conditions to ensure the accuracy of parameter estimation. Error of state variable estimation The convergence of [the mechanism]. Under this mechanism, on the one hand, through [the mechanism's] convergence. On the one hand, the dynamic compensation mechanism adapts to changes in system state; on the other hand, through... Structural constraints maintain the stability of the algorithm, ultimately achieving coordinated convergence of parameter estimation errors and state estimation errors.

[0053] In one embodiment, the exhaust pressure predicted by the adaptive observer based on the state vector and the average exhaust pressure of the previous time step discrete dynamic model is compared with the real-time pressure signal of the current exhaust manifold to calculate the exhaust pressure estimation error, which is specifically expressed as follows:

[0054] in, To predict pressure for the observer, This is a real-time pressure signal.

[0055] The estimation error is used to correct the observer's state vector, achieving joint correction of exhaust pressure state and exhaust efficiency, so that the predicted value gradually approaches the actual measured value. Through the error feedback mechanism, the state vector is adjusted in real time with changes in pressure measurement, ensuring the dynamic tracking accuracy of exhaust efficiency estimation and maintaining stability and convergence under different engine operating conditions.

[0056] Step S104: Based on the online estimation results of exhaust efficiency, obtain the mass of exhaust gas discharged in each cycle and calculate the amount of residual exhaust gas in the cylinder.

[0057] Based on the online estimation results of exhaust efficiency, the overall emission characteristics of exhaust gas at the exhaust valve can be obtained. Exhaust efficiency reflects the ratio of the actual exhaust gas volume to the theoretical exhaust gas volume, and therefore can be used as a key reference for estimating the mass of exhaust gas discharged in each cycle. Based on this online estimation result, the actual exhaust flow rate and exhaust efficiency can be combined in each working cycle to obtain the total exhaust gas volume for that cycle.

[0058] In one embodiment, the exhaust gas mass flow rate at the exhaust valve is calculated based on the obtained online estimate of exhaust efficiency. Specifically, the online estimate of exhaust efficiency is used to calculate the mass flow rate. By combining parameters such as exhaust pressure, cylinder displacement, and engine speed, and substituting them into the constructed exhaust gas mass flow model, the exhaust gas mass flow rate at each moment can be obtained. Within each working cycle, the exhaust gas mass flow rate is integrated along the crankshaft angle. The total exhaust gas mass discharged from the cylinder in that cycle is obtained from the moment corresponding to the crankshaft angle from 0° to 360°. Specifically, it is expressed as:

[0059] in, and These represent the times corresponding to crankshaft rotation angles of 0° and 360°, respectively.

[0060] In another embodiment, based on the obtained mass of exhaust gas discharged from the cylinder per cycle and intake quality and the mass of fuel entering the cylinder The principle of mass conservation is used to measure the residual exhaust gas volume in the cylinder. An estimate is made. Specifically, the mass of the exhaust gas recirculated out is deducted from the total mass of the incoming gas, while simultaneously considering the amount of fuel entering the cylinder and excluding the instantaneous mass flow rate into the cylinder. The influence of this on the quality of exhaust gas remaining in the cylinder is determined. Specifically, it is expressed as follows:

[0061] This formula can be discretized based on actual sampling and integration methods to enable online calculation in the control system. This calculation method allows for real-time and accurate reflection of the residual exhaust gas state within the cylinder, providing precise input parameters for combustion control and emission optimization of the hydrogen range extender.

[0062] In one application embodiment, it is provided Figure 4 The diagram shows the execution flow for calculating residual exhaust gas. Specifically, it includes: First, key engine operating information, including engine speed, load, intake pressure, and intake temperature, is collected in real time using sensors. Based on this information, the current operating condition of the engine is determined. The engine condition not only serves as the basis for subsequent exhaust pressure estimation and exhaust efficiency calculations but also directly affects exhaust characteristics.

[0063] After obtaining the current engine state, online estimation of exhaust pressure is performed. By combining the discrete dynamic model of the average exhaust pressure with the state vector of the previous moment, the estimated exhaust pressure value for the current moment is obtained. Subsequently, the estimated value is compared with the actual measured pressure, and the pressure estimation error is calculated. This error reflects the deviation between the predicted exhaust pressure and the actual situation, providing a reference for online correction of exhaust efficiency.

[0064] Next, based on the exhaust pressure estimation results and pressure error, online estimation of exhaust efficiency is performed. The exhaust efficiency estimation results, combined with the engine's current operating conditions, reflect the change in the actual exhaust gas volume relative to the theoretical value, providing a crucial basis for exhaust flow calculation. By updating the state vector recursively, the pressure estimation error is gradually reduced, enabling dynamic adjustment of exhaust efficiency according to operating conditions.

[0065] After obtaining the exhaust efficiency estimate, the exhaust gas mass flow rate at the exhaust valve can be calculated, and the total exhaust gas mass discharged per cycle can be further obtained. The exhaust gas mass discharged per cycle is combined with the intake mass and the fuel mass entering the cylinder. Through the principle of mass conservation, the residual exhaust gas volume in the cylinder can be estimated, dynamically reflecting the exhaust gas state in the cylinder at the end of each working cycle.

[0066] Through the above-mentioned continuous execution steps, real-time estimation of engine exhaust pressure, exhaust efficiency, exhaust flow rate, and residual exhaust gas volume in the cylinder can be achieved, forming a complete exhaust condition monitoring and analysis process, providing a reliable basis for combustion control, exhaust gas recirculation, and emission optimization.

[0067] In the above embodiments, by utilizing the online estimation results of exhaust efficiency and the discrete dynamic model of the average exhaust pressure, the calculation of exhaust gas mass per cycle and the real-time estimation of in-cylinder residual exhaust gas volume are achieved. This method can fully utilize information such as engine speed, load, intake pressure, and temperature obtained from conventional engine sensors, and can complete the dynamic calculation of residual exhaust gas during actual vehicle operation without relying on extensive simulations or complex pulse spectrum calibration. This not only significantly improves the calculation accuracy but also has strong adaptability, maintaining the stability and reliability of the estimation under different operating conditions. Simultaneously, the online estimation of exhaust efficiency and exhaust gas mass achieves coordinated convergence of parameter estimation errors and state estimation errors, making the calculation of residual exhaust gas volume more accurate. This provides timely and reliable input information for combustion control, exhaust gas recirculation, and emission optimization of hydrogen range extenders, reducing development costs and calibration workload, and improving the feasibility and engineering efficiency of practical vehicle applications.

[0068] In one embodiment, an in-cylinder residual exhaust gas estimation device for a hydrogen-powered range extender is provided, referencing Figure 5 As shown, the in-cylinder residual exhaust gas estimation device 500 for the hydrogen-fueled range extender may include: The exhaust gas flow model construction module 501 is used to construct an exhaust gas flow model at the exhaust valve based on engine structural parameters, pressure and temperature signals of the exhaust manifold, and exhaust efficiency; the exhaust efficiency is a time-varying parameter to be identified. The exhaust pressure average discrete dynamic model construction module 502 is used to construct the exhaust pressure average discrete dynamic model of the exhaust manifold based on the inlet exhaust gas flow rate and the outlet exhaust gas flow rate of the exhaust manifold, and according to the mass conservation relationship and the ideal gas law; wherein, the inlet exhaust gas flow rate of the exhaust manifold is determined by the exhaust gas flow rate model of the exhaust valve, and the outlet exhaust gas flow rate of the exhaust manifold is obtained by the flow sensor. The adaptive observer estimation module 503 is used to construct an adaptive observer based on the discrete dynamic model of the average exhaust pressure, and to estimate the exhaust efficiency through the adaptive observer. The residual exhaust gas calculation module 504 is used to obtain the mass of exhaust gas discharged in each cycle and calculate the residual exhaust gas volume in the cylinder based on the online estimation result of exhaust efficiency.

[0069] In one embodiment, the adaptive observer estimation module 503 is specifically used to: update the state vector of the adaptive observer based on the current exhaust manifold pressure signal, the outlet exhaust gas flow rate and the exhaust manifold volume; By using the updated state vector and combining it with the discrete dynamic model of the average exhaust pressure, the exhaust efficiency is estimated on the ground, and the real-time estimate of the exhaust efficiency is obtained.

[0070] In one embodiment, the adaptive observer estimation module 503 is specifically used to: introduce a gain matrix to adjust the update magnitude of the state vector during the process of updating the state vector.

[0071] In one embodiment, the adaptive observer estimation module 503 is specifically used to: introduce dynamic compensation parameters and structural constraint parameters during the process of updating the observer state vector; The state vector update is corrected based on dynamic compensation parameters and structural constraint parameters.

[0072] In one embodiment, the adaptive observer estimation module 503 is specifically used to: compare the exhaust pressure predicted by the adaptive observer based on the state vector and the average exhaust pressure of the previous time step discrete dynamic model with the current exhaust manifold pressure signal to obtain the exhaust pressure estimation error. The state vector of the adaptive observer is corrected based on the exhaust pressure estimation error.

[0073] In one embodiment, the residual exhaust gas volume calculation module 504 is specifically used to: calculate the exhaust gas mass flow rate at the exhaust valve based on the online estimation result of exhaust efficiency; The exhaust gas mass flow rate at the exhaust valve is integrated within each working cycle to obtain the exhaust gas mass discharged from the cylinder in each cycle.

[0074] In one embodiment, the residual exhaust gas calculation module 504 is specifically used to: calculate the residual exhaust gas in the cylinder based on the mass conservation relationship, using the mass of exhaust gas discharged from the cylinder in each cycle, the mass of intake air, and the mass of fuel entering the cylinder.

[0075] Specific limitations regarding the in-cylinder residual exhaust gas estimation device 500 for hydrogen-powered range extenders can be found in the limitations of the in-cylinder residual exhaust gas estimation method for hydrogen-powered range extenders mentioned above, and will not be repeated here. Each module in the aforementioned in-cylinder residual exhaust gas estimation device 500 can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the operations corresponding to each module.

[0076] In one embodiment, a vehicle is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement a method for estimating in-cylinder residual exhaust gas in a hydrogen range extender.

[0077] In one embodiment, a computer storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements a method for estimating in-cylinder residual exhaust gas in a hydrogen-fueled range extender.

[0078] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0080] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender, characterized in that, include: Based on engine structural parameters, pressure and temperature signals from the exhaust manifold, and exhaust efficiency, a model of exhaust gas flow at the exhaust valve is constructed. The exhaust efficiency is a time-varying parameter to be identified; Based on the inlet exhaust gas flow rate and outlet exhaust gas flow rate of the exhaust manifold, and according to the mass conservation relationship and the ideal gas law, a discrete dynamic model of the average exhaust pressure of the exhaust manifold is constructed; wherein, the inlet exhaust gas flow rate of the exhaust manifold is determined by the exhaust gas flow rate model of the exhaust valve, and the outlet exhaust gas flow rate of the exhaust manifold is obtained by the flow sensor. An adaptive observer is constructed based on the discrete dynamic model of the average exhaust pressure, and the exhaust efficiency is estimated by the adaptive observer. Based on the online estimation results of the exhaust efficiency, the mass of exhaust gas discharged per cycle is obtained and the amount of residual exhaust gas in the cylinder is calculated.

2. The method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to claim 1, characterized in that, The estimation of the exhaust efficiency using the adaptive observer includes... Update the state vector of the adaptive observer based on the current exhaust manifold pressure signal, outlet exhaust gas flow rate and exhaust manifold volume; Using the updated state vector and the discrete dynamic model of the average exhaust pressure, the exhaust efficiency is estimated on the ground to obtain the real-time estimate of the exhaust efficiency.

3. The method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to claim 2, characterized in that, During the process of updating the state vector, a gain matrix is ​​introduced to adjust the update magnitude of the state vector.

4. The method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to claim 2, characterized in that, During the process of updating the observer state vector, dynamic compensation parameters and structural constraint parameters are introduced; The state vector update is corrected based on the dynamic compensation parameters and the structural constraint parameters.

5. The method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to any one of claims 2 to 4, characterized in that, The exhaust pressure predicted by the adaptive observer based on the state vector of the previous time step and the discrete dynamic model of the average exhaust pressure is compared with the current exhaust manifold pressure signal to obtain the exhaust pressure estimation error. The state vector of the adaptive observer is corrected based on the exhaust pressure estimation error.

6. The method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to claim 1, characterized in that, Obtain the mass of exhaust gas discharged in each cycle, including: Based on the online estimation results of the exhaust efficiency, the exhaust gas mass flow rate at the exhaust valve is calculated; The exhaust gas mass flow rate at the exhaust valve is integrated within each working cycle to obtain the exhaust gas mass discharged from the cylinder in each cycle.

7. The method for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender according to claim 6, characterized in that, Calculate the amount of residual exhaust gas in the cylinder, including: Based on the law of conservation of mass, the amount of residual exhaust gas in the cylinder is calculated using the mass of exhaust gas discharged from the cylinder, the mass of intake air, and the mass of fuel entering the cylinder in each cycle.

8. A device for estimating residual exhaust gas in the cylinder of a hydrogen-fueled range extender, characterized in that, include: The exhaust gas flow model construction module is used to construct an exhaust gas flow model at the exhaust valve based on engine structural parameters, pressure and temperature signals from the exhaust manifold, and exhaust efficiency; the exhaust efficiency is a time-varying parameter to be identified. The module for constructing a discrete dynamic model of the average exhaust pressure is used to construct a discrete dynamic model of the average exhaust pressure of the exhaust manifold based on the inlet exhaust gas flow rate and the outlet exhaust gas flow rate of the exhaust manifold, and according to the mass conservation relationship and the ideal gas law. The inlet exhaust gas flow rate of the exhaust manifold is determined by the exhaust gas flow rate model of the exhaust valve, and the outlet exhaust gas flow rate of the exhaust manifold is obtained by the flow sensor. An adaptive observer estimation module is used to construct an adaptive observer based on the discrete dynamic model of the average exhaust pressure, and to estimate the exhaust efficiency through the adaptive observer. The residual exhaust gas volume calculation module is used to obtain the mass of exhaust gas discharged in each cycle and calculate the residual exhaust gas volume in the cylinder based on the online estimation result of the exhaust efficiency.

9. A vehicle comprising a memory and a processor, said memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method for estimating in-cylinder residual exhaust gas of the hydrogen-fueled range extender according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for estimating in-cylinder residual exhaust gas of the hydrogen-fueled range extender according to any one of claims 1 to 7.

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