Vehicle control method and device, vehicle and storage medium

Abstract

The invention provides a vehicle control method and device, a vehicle and a storage medium, and relates to the technical field of vehicles. The method comprises the steps that when the running state of an engine of the vehicle meets the preset catalyst oxygen storage condition, the target air-fuel ratio for the engine of the vehicle is determined according to the obtained actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and the engine is controlled to run according to the target air-fuel ratio. When the running state of the engine of the vehicle meets the corresponding conditions, the target air-fuel ratio for the engine is determined according to the actual oxygen storage amount and / or the actual oxygen storage rate, accurate control over emission of the vehicle engine is conveniently achieved, the target air-fuel ratio is dynamically adjusted, and the vehicle emission control efficiency is improved. The amount of oxygen entering the catalyst and the proportion of tail gas generated by engine combustion are kept balanced, emission control is optimized, and more accurate and efficient vehicle engine emission control is achieved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a vehicle control method, device, vehicle and storage medium. Background Art

[0002] With increasing attention paid to environmental protection, in terms of vehicles, as a key component in the exhaust system, the three-way catalytic converter effectively reduces harmful gases such as carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) in the exhaust through redox reactions, and plays an important role in meeting emission standards.

[0003] During engine operation, when excess air enters the catalyst (such as the air-fuel ratio of the mixture is higher than the theoretical air-fuel ratio), the three-way catalytic converter can store oxygen through its internal oxygen storage material and release the stored oxygen when the oxygen required for the redox reaction is insufficient. In this way, it ensures that the reducing components such as carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas are fully oxidized, and at the same time promotes the reduction of nitrogen oxides (NOx) to nitrogen (N2), thereby improving the conversion efficiency of the catalyst and reducing the emission of harmful gases.

[0004] Therefore, the oxygen storage capacity directly affects the operating efficiency of the catalyst, and affects the emission control effect and exhaust purification efficiency of the vehicle engine. However, in the prior art, the determination of the oxygen storage capacity is usually estimated by monitoring the voltage signal of the rear oxygen sensor in the vehicle exhaust system, which is not comprehensive, and the measurement value of the rear oxygen sensor has a certain delay, and the estimation accuracy is low, which affects the accuracy of vehicle engine emissions. Summary of the invention

[0005] The problem solved by the present invention is: how to achieve accurate control of vehicle engine emissions.

[0006] In order to solve the above problems, the present invention provides a vehicle control method, device, vehicle and storage medium.

[0007] In a first aspect, the present invention provides a vehicle control method, comprising:

[0008] When the operating state of the vehicle's engine meets the preset catalyst oxygen storage conditions, the target air-fuel ratio of the vehicle's engine is determined based on the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst of the vehicle's exhaust system that have been acquired, and the engine operation is controlled based on the target air-fuel ratio.

[0009] Optionally, the catalyst oxygen storage condition includes the engine being in a fuel cut-off state, a lean-burn state or a starting state.

[0010] Optionally, determining a target air-fuel ratio for an engine of the vehicle according to the acquired actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and controlling the operation of the engine according to the target air-fuel ratio comprises:

[0011] According to the first operating parameter of the engine and the second operating parameter of the catalyst that have been acquired, determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount; according to the actual oxygen storage amount, determining the target air-fuel ratio, and controlling the operation of the engine according to the target air-fuel ratio;

[0012] And / or, based on the first operating parameter and the second operating parameter, determine the current total oxygen storage capacity of the catalyst as the actual oxygen storage capacity, and determine the current maximum oxygen storage capacity of the catalyst; determine the oxygen storage rate of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity; determine the target air-fuel ratio based on the oxygen storage rate, and control the engine operation according to the target air-fuel ratio.

[0013] Optionally, determining the current total oxygen storage capacity of the catalyst as the actual oxygen storage capacity includes:

[0014] According to the first oxygen storage amount of the catalyst in a previous preset cycle and the second oxygen storage amount increased in a current preset cycle, it is determined that the sum of the first oxygen storage amount and the second oxygen storage amount is the current actual oxygen storage amount of the catalyst.

[0015] Optionally, the catalyst includes a first catalyst and a second catalyst, the exhaust system further includes an exhaust pipe, and the exhaust port of the engine, the first catalyst and the second catalyst are sequentially connected through the exhaust pipe;

[0016] The step of determining, based on a first oxygen storage amount of the catalyst in a previous preset cycle and a second oxygen storage amount increased in a current preset cycle, the sum of the first oxygen storage amount and the second oxygen storage amount as the current actual oxygen storage amount of the catalyst comprises:

[0017] Determine the second oxygen storage amount of the first catalyst according to the amount of oxygen adsorbed and consumed by the first catalyst in a current preset period, and determine the current first total oxygen storage amount of the first catalyst according to the second oxygen storage amount of the first catalyst and the first oxygen storage amount of the first catalyst that has been acquired; determine the second oxygen storage amount of the second catalyst according to the amount of oxygen adsorbed and consumed by the second catalyst in a current preset period, and determine the current second total oxygen storage amount of the second catalyst according to the second oxygen storage amount of the second catalyst and the first oxygen storage amount of the second catalyst that has been acquired;

[0018] The sum of the first total oxygen storage capacity and the second total oxygen storage capacity is determined as the actual oxygen storage capacity.

[0019] Optionally, before determining that the sum of the first oxygen storage amount and the second oxygen storage amount is the current actual oxygen storage amount of the catalyst based on the first oxygen storage amount in the previous preset cycle of the catalyst and the second oxygen storage amount increased in the current preset cycle, determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes:

[0020] determining the amount of oxygen adsorbed by the first catalyst in the current preset period according to a first excess amount of air entering the first catalyst in the current preset period, a first oxygen adsorption rate of the first catalyst, and a first adaptive coefficient; determining the amount of oxygen consumed by the first catalyst in the current preset period according to a first excess amount of fuel entering the first catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine;

[0021] The amount of oxygen adsorbed by the second catalyst within the current preset period is determined based on a second excess air amount entering the second catalyst within the current preset period, a second oxygen adsorption rate and a second adaptive coefficient of the second catalyst; the amount of oxygen consumed by the second catalyst within the current preset period is determined based on a second excess fuel amount entering the second catalyst within the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine.

[0022] Optionally, the step of determining the amount of oxygen adsorbed by the first catalyst within the current preset period according to a first excess amount of air entering the first catalyst within the current preset period, a first oxygen adsorption rate of the first catalyst, and a first adaptive coefficient; and determining the amount of oxygen consumed by the first catalyst within the current preset period according to a first excess amount of fuel entering the first catalyst within the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine, the step of determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes:

[0023] The first excess air volume is determined according to the total air intake volume of the engine and a first preset coefficient; wherein, if the engine is in a fuel cut-off state, the first preset coefficient is the fuel cut-off rate of the engine; if the engine is not in the fuel cut-off state, the first preset coefficient is the ratio of the difference between the excess air coefficient and 1 to the excess air coefficient; the excess air coefficient is the ratio of the actual air-fuel ratio of the total air intake volume to the theoretical air-fuel ratio, and the actual air-fuel ratio is the ratio of the total air intake volume to the total fuel intake volume of the engine;

[0024] The first excess fuel amount is determined according to the total air intake amount of the engine, the second preset coefficient and the theoretical air-fuel ratio; wherein, if the engine is in the fuel cut-off state, the second preset coefficient is 0; if the engine is not in the fuel cut-off state, the second preset coefficient is the ratio of the difference between the excess air coefficient and 1 to the excess air coefficient;

[0025] Before determining the amount of oxygen adsorbed by the second catalyst in the current preset period according to a second excess air amount entering the second catalyst in the current preset period, a second oxygen adsorption rate of the second catalyst and a second adaptive coefficient; and determining the amount of oxygen consumed by the second catalyst in the current preset period according to a second excess fuel amount entering the second catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine, the determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes:

[0026] Determine the second excess air amount according to the first total oxygen storage amount, the maximum oxygen storage amount and the amount of unabsorbed oxygen of the first catalyst at present; wherein the amount of unabsorbed oxygen is determined according to the total air intake amount, the fuel cut-off rate and the amount of oxygen adsorbed by the first catalyst in a current preset period;

[0027] The second excess fuel amount is determined according to the first excess fuel amount, the fuel adsorption rate of the first catalyst, and the first adaptive coefficient.

[0028] Optionally, determining the oxygen storage rate of the catalyst according to the actual oxygen storage amount and the maximum oxygen storage amount includes:

[0029] The sum of a current first maximum oxygen storage capacity of the first catalyst and a current second maximum oxygen storage capacity of the second catalyst is determined as the maximum oxygen storage capacity, and the ratio of the actual oxygen storage capacity to the maximum oxygen storage capacity is determined as the oxygen storage rate.

[0030] Optionally, the exhaust system further comprises a post oxygen sensor disposed on the exhaust pipe, wherein the post oxygen sensor is located between the first catalyst and the second catalyst; and the vehicle control method further comprises:

[0031] When the first operating parameter of the engine, the second operating parameter of the catalyst and the third operating parameter of the rear oxygen sensor meet the preset adaptive coefficient calculation conditions, the current theoretical maximum oxygen storage capacity and the actual maximum oxygen storage capacity of the first catalyst are determined, and the ratio of the actual maximum oxygen storage capacity to the theoretical maximum oxygen storage capacity is determined and updated as the first adaptive coefficient.

[0032] Optionally, determining a target air-fuel ratio for an engine of the vehicle according to the acquired actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and controlling the operation of the engine according to the target air-fuel ratio comprises:

[0033] When the actual oxygen storage amount is greater than a first preset value or the actual oxygen storage rate is greater than a second preset value, if the engine is in a fuel-cut state, a first preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the first preset target air-fuel ratio to achieve fuel-cutting and deoxygenation of the catalyst; if the engine is in a starting state, a second preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the second preset target air-fuel ratio to achieve starting deoxygenation of the catalyst.

[0034] Optionally, determining a target air-fuel ratio for an engine of the vehicle according to the acquired actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and controlling the operation of the engine according to the target air-fuel ratio comprises:

[0035] In response to an engine shutdown command, if the actual oxygen storage amount is greater than a third preset value or the actual oxygen storage rate is greater than a fourth preset value, a third preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the third preset target air-fuel ratio. When the actual oxygen storage amount is less than or equal to the third preset value, or the actual oxygen storage rate is less than or equal to the fourth preset value, the engine is controlled to shut down.

[0036] In a second aspect, the present invention provides a control device, comprising:

[0037] A control unit is used to determine a target air-fuel ratio for the engine of the vehicle based on an actual oxygen storage amount and / or an actual oxygen storage rate of the catalyst of the exhaust system of the vehicle when the operating state of the engine of the vehicle meets a preset catalyst oxygen storage condition, and control the engine operation based on the target air-fuel ratio.

[0038] In a third aspect, the present invention provides a vehicle, comprising a memory and a processor;

[0039] The memory is used to store computer programs;

[0040] The processor is used to implement the vehicle control method as described in the first aspect when executing the computer program.

[0041] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program. When the computer program is read and executed by a processor, the vehicle control method as described in the first aspect is implemented.

[0042] Compared with the prior art, the present invention has the following beneficial effects: when the operating state of the vehicle's engine meets the preset catalyst oxygen storage condition, the present invention determines the target air-fuel ratio for controlling the engine operation according to the actual oxygen storage amount of the catalyst, so as to realize the precise control of the vehicle engine emission; or determines the target air-fuel ratio for controlling the engine operation according to the actual oxygen storage rate, so as to realize the dynamic adjustment of the target air-fuel ratio, so that the amount of oxygen entering the catalyst and the ratio of the exhaust gas generated by the engine combustion are always kept in balance (or approaching balance), and the emission control is optimized, and it is still applicable when the oxygen storage capacity of the catalyst decreases (or ages), and has the characteristic of strong applicability; or determines the target air-fuel ratio for controlling the engine operation according to the actual oxygen storage amount and the actual oxygen storage rate, so as to comprehensively give play to the above-mentioned advantages of both, that is, to improve the accuracy and adaptability of the target air-fuel ratio determination, ensure that the catalyst operates in the best state, optimize the engine combustion efficiency, reduce harmful emissions in the exhaust gas, and realize more accurate and efficient emission control. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of a vehicle control method according to an embodiment of the present invention;

[0044] Figure 2 is a structural block diagram of a control device in an embodiment of the present invention;

[0045] Figure 3 Schematic diagram of the structure of the memory and processor of the vehicle in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0048] Combination Figure 1 As shown, an embodiment of the present invention provides a vehicle control method, including:

[0049] Step 100: When the operating state of the vehicle's engine meets the preset catalyst oxygen storage condition, determine the target air-fuel ratio of the vehicle's engine based on the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst of the vehicle's exhaust system that has been acquired, and control the engine operation based on the target air-fuel ratio.

[0050] For vehicles with engines (or fuel engines), such as fuel vehicles, hybrid vehicles, etc., due to reasons such as incomplete fuel combustion, exhaust emissions that pollute the atmospheric environment and contain harmful components will be generated. In this regard, a catalyst is set in the exhaust system of the vehicle to harmlessly convert harmful gases in the exhaust gas, so as to effectively reduce the emission of harmful exhaust gas and reduce the pollution caused to the atmospheric environment. Among them, the actual oxygen storage capacity or actual oxygen storage rate of the catalyst is one of the important parameters for engine operation control. The accuracy of its measurement or calculation affects the precise control of the engine, and then affects the exhaust gas purification efficiency and vehicle emission control. The method of this embodiment is used to achieve accurate measurement of the actual oxygen storage capacity or actual oxygen storage rate of the catalyst, and achieve accurate control of vehicle engine emissions.

[0051] Specifically, in the method of this embodiment, through step 100, according to the current operating state of the vehicle's engine that has been acquired, it is determined whether the current operating state of the engine meets the preset catalyst oxygen storage condition, wherein the catalyst oxygen storage condition is the engine operating state that makes the catalyst in the oxygen storage condition (such as the excess oxygen in the gas entering the catalyst is stored in the oxygen storage material of the catalyst). If satisfied, then according to the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst of the exhaust system of the vehicle that has been acquired, the target air-fuel ratio of the engine of the vehicle is determined, and the engine operation is controlled according to the target air-fuel ratio. Among them, for the acquisition of the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst, the actual oxygen storage amount or actual oxygen storage rate of the catalyst can be determined in combination with the operating parameters of the vehicle's engine (recorded as the first operating parameters, such as the intake volume, the operating mode, etc.) and the operating parameters of the catalyst in the exhaust system of the vehicle (recorded as the second operating parameters, such as the oxygen adsorption rate, the oxygen storage capacity, etc.). In this way, the various factors that may affect the oxygen storage capacity or oxygen storage rate of the catalyst are comprehensively and more fully considered to ensure that the actual oxygen storage capacity or actual oxygen storage rate of the catalyst is calculated more accurately, that is, the accuracy of the calculation of the actual oxygen storage capacity or actual oxygen storage rate of the catalyst is improved, thereby providing reliable data support for the precise control of engine operation, thereby optimizing the vehicle's emission control effect and exhaust purification efficiency, and achieving accurate control of vehicle engine emissions.

[0052] Considering that the actual oxygen storage capacity and the actual oxygen storage rate of the catalyst reflect the oxygen adsorption saturation degree of the oxygen storage material inside the current catalyst, it can reflect the oxygen reserve capacity of the catalyst that can be used for oxidation reaction or reduction reaction. In step 100, according to at least one of the actual oxygen storage capacity and the actual oxygen storage rate, the target air-fuel ratio for the engine (i.e., the ratio of the target engine intake air volume to the fuel volume) is determined, and the engine operation is controlled according to the target air-fuel ratio. Exemplarily, when the actual oxygen storage capacity (or the actual oxygen storage rate) of the catalyst is low, there may be a lack of sufficient oxygen inside the catalyst for oxidation reaction. At this time, it is necessary to adjust the target air-fuel ratio to make the mixture slightly leaner and increase the amount of oxygen entering the catalyst; and when the actual oxygen storage capacity (or the actual oxygen storage rate) of the catalyst is high, it is necessary to adjust the target air-fuel ratio to make the mixture slightly richer to reduce the amount of oxygen entering the catalyst and balance the oxygen storage state. In this way, according to the set target air-fuel ratio, the ratio of the engine's fuel injection amount and air intake amount is adjusted, that is, the ratio of the components of the mixed gas entering the engine is changed, so that the catalyst can be maintained in the optimal oxygen storage state (or the optimal operating state, at this time, the catalyst oxygen storage capacity or oxygen storage rate is in the high-efficiency range of the redox reaction), while ensuring the normal operation of the engine, maximizing the conversion efficiency of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) in engine emissions, thereby reducing the emission of harmful components in vehicle exhaust gas, achieving accurate and efficient control of vehicle engine emissions, and achieving coordinated optimization of emission control and engine combustion performance.

[0053] Among them, the actual oxygen storage can directly reflect the oxygen reserve of the oxygen storage material in the catalyst, which is an absolute value indicator of oxygen adsorption in the catalyst and can provide accurate data on the current oxygen storage in the catalyst. If the target air-fuel ratio is determined based on the actual oxygen storage, on the one hand, the actual oxygen storage can directly quantify the oxygen reserve, and it can be clear whether the oxygen entering the catalyst is sufficient to support the subsequent oxidation reaction or reduction reaction, avoiding the extreme working conditions of insufficient or excessive oxygen; on the other hand, the absolute value characteristics of the actual oxygen storage can be used to accurately calculate the target air-fuel ratio, ensure that the air-fuel ratio in the combustion process is more accurate, and improve the combustion efficiency; on the other hand, when the engine is running at high load or the working condition is switched quickly, the actual oxygen storage can provide stable data support, making the air-fuel ratio adjustment more reliable. The actual oxygen storage rate indicates the relative efficiency and current use status of the oxygen adsorption of the catalyst, and is a proportional embodiment of the oxygen adsorption capacity of the catalyst. It can reflect the working status of the catalyst (such as adsorption capacity, saturation), and can also indicate whether the catalyst is in the best operating state, or whether there is a risk of excessive storage or loss of oxygen. If the target air-fuel ratio is determined based on the actual oxygen storage rate, on the one hand, it can be evaluated whether the catalyst is currently in an efficient redox range, so as to facilitate the dynamic adjustment of the target air-fuel ratio, so that the amount of oxygen entering the catalyst and the proportion of exhaust gas generated by engine combustion are always balanced (or close to balance), and emission control is optimized; on the other hand, even if the oxygen storage capacity of the catalyst decreases due to aging and other reasons, the actual oxygen storage rate can still be used by the engine control unit to adjust the target air-fuel ratio for the engine by reflecting the proportional change of the oxygen storage capacity, so that the catalyst can still maintain the best working state as much as possible under the condition of performance degradation, and improve the effect of engine combustion and emission control. In summary, the actual oxygen storage amount focuses on providing absolute oxygen reserve information for precise control; while the actual oxygen storage rate focuses on reflecting the dynamic working efficiency and health status of the catalyst, and is still applicable when the oxygen storage capacity of the catalyst decreases, for flexible optimization. And the above advantages of both can be brought into play by combining the two, that is, improving the accuracy and adaptability of the target air-fuel ratio determination, ensuring that the catalyst operates in the best state, optimizing the engine combustion efficiency, reducing harmful emissions in the exhaust gas, and achieving more accurate and efficient emission control.

[0054] In this way, when the operating state of the vehicle's engine meets the preset catalyst oxygen storage conditions, the method of this embodiment determines the target air-fuel ratio for controlling the engine operation according to the actual oxygen storage amount of the catalyst, which is convenient for realizing precise control of the vehicle engine emissions; or determines the target air-fuel ratio for controlling the engine operation according to the actual oxygen storage rate, which is convenient for dynamically adjusting the target air-fuel ratio, so that the amount of oxygen entering the catalyst and the ratio of exhaust gas generated by engine combustion are always balanced (or approaching balance), optimize emission control, and it is still applicable when the oxygen storage capacity of the catalyst decreases (or ages), and has the characteristic of strong applicability; or determines the target air-fuel ratio for controlling the engine operation according to the actual oxygen storage amount and the actual oxygen storage rate, so as to comprehensively give play to the above-mentioned advantages of both, that is, to improve the accuracy and adaptability of the target air-fuel ratio determination, ensure that the catalyst operates in the best state, optimize the engine combustion efficiency, reduce harmful emissions in the exhaust gas, and realize more accurate and efficient emission control.

[0055] Optionally, the catalyst oxygen storage condition includes the engine being in a fuel cut-off state, a lean-burn state or a starting state.

[0056] Specifically, considering that the air (or oxygen) content in the exhaust gas of the engine is high when the engine is in the fuel cut-off state, lean burn state or starting state, at this time, the catalyst enters the oxygen storage state, and its oxygen storage material can adsorb oxygen, so that the oxygen storage amount or oxygen storage rate of the catalyst changes with the oxygen adsorption process. Therefore, the catalyst oxygen storage conditions include the engine being in the fuel cut-off state, lean burn state or starting state.

[0057] Among them, for the fuel cut-off state, in the fuel cut-off state, fuel injection stops (fuel supply to all or part of the cylinders of the engine is stopped), the proportion of unconsumed air in the exhaust gas discharged by the engine and entering the catalyst is high, and the oxygen concentration is high. At this time, the catalyst is in an oxygen storage condition, and the oxygen storage capacity is increased. For the lean burn state, in the lean burn state, the mixture is lean, that is, the air content in the mixture is high, and the oxygen content in the exhaust gas discharged by the engine and entering the catalyst increases significantly. At this time, the catalyst is in an oxygen storage condition, and the oxygen storage capacity is increased. For the starting state, in the starting state, the combustion efficiency of the engine is low in the initial stage of operation, and the proportion of unconsumed air in the exhaust gas discharged by the engine and entering the catalyst is high, and the oxygen concentration is high. At this time, the catalyst is in an oxygen storage condition, and the oxygen storage capacity is increased.

[0058] Optionally, determining a target air-fuel ratio for an engine of the vehicle according to an actual oxygen storage amount and / or an actual oxygen storage rate of a catalyst of an exhaust system of the vehicle that has been acquired, and controlling the engine operation according to the target air-fuel ratio includes:

[0059] According to the first operating parameter of the engine and the second operating parameter of the catalyst that have been obtained, determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount; according to the actual oxygen storage amount, determining the target air-fuel ratio, and controlling the operation of the engine according to the target air-fuel ratio;

[0060] And / or, based on the first operating parameter and the second operating parameter, determine the current total oxygen storage capacity of the catalyst as the actual oxygen storage capacity, and determine the current maximum oxygen storage capacity of the catalyst; determine the oxygen storage rate of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity; determine the target air-fuel ratio based on the oxygen storage rate, and control the engine operation according to the target air-fuel ratio.

[0061] Specifically, in the method of this embodiment, if it is necessary to determine the actual oxygen storage capacity of the catalyst at present, the total oxygen storage capacity of the catalyst at present is determined as the actual oxygen storage capacity according to the first operating parameter of the engine (such as the intake volume, the operating mode, etc.) and the second operating parameter of the catalyst of the exhaust system of the vehicle (such as the oxygen adsorption rate, the oxygen storage capacity, etc.) that have been obtained. Exemplarily, if there is only one catalyst in the exhaust system of the vehicle, the total oxygen storage capacity of the catalyst at present calculated according to the first operating parameter and the second operating parameter is the actual oxygen storage capacity of the catalyst at present; if there are multiple catalysts in the exhaust system of the vehicle, the sum of the current oxygen storage capacity of each catalyst calculated according to the first operating parameter and the second operating parameter (the total oxygen storage capacity) is the actual oxygen storage capacity of the catalyst at present.

[0062] If it is necessary to determine the current actual oxygen storage rate of the catalyst, or to determine the current actual oxygen storage amount and actual oxygen storage rate of the catalyst, first determine the current total oxygen storage amount of the catalyst as the actual oxygen storage amount based on the first operating parameter of the engine and the second operating parameter of the catalyst of the vehicle's exhaust system, and determine the current maximum oxygen storage amount of the catalyst, and determine the oxygen storage rate of the catalyst as the ratio of the actual oxygen storage amount to the maximum oxygen storage amount. If there is only one catalyst in the vehicle's exhaust system, the actual oxygen storage amount to be determined is the current total oxygen storage amount of the catalyst, and the maximum oxygen storage amount to be determined is the maximum oxygen storage amount of the catalyst in the current operating state; if there are multiple catalysts in the vehicle's exhaust system, the actual oxygen storage amount to be determined is the sum of the current oxygen storage amount of each catalyst, and the maximum oxygen storage amount to be determined is the sum of the maximum oxygen storage amount of each catalyst in the current operating state.

[0063] In this way, when the operating state of the vehicle's engine meets the preset catalyst oxygen storage conditions, the method of this embodiment comprehensively and fully considers the first operating parameters of the engine and the second operating parameters of the catalyst that may affect the actual oxygen storage capacity or actual oxygen storage rate of the catalyst, so as to improve the accuracy of the measurement of the actual oxygen storage capacity or actual oxygen storage rate of the catalyst, thereby providing reliable data support for the precise control of the engine operation.

[0064] Optionally, considering that the maximum oxygen storage capacity of the catalyst is affected by the catalyst temperature, catalyst aging degree and engine start time, the influence of these three factors on the catalyst is independent, that is, the three factors do not directly affect each other. In general, the MAP (mapping or correspondence) of the influence of the catalyst temperature and catalyst aging degree on the maximum oxygen storage capacity of the catalyst can be directly provided by the catalyst supplier, or calibrated when the engine is cut off from oil; the influence of the time after the engine is started on the maximum oxygen storage capacity is mainly caused by the engine introducing excessive air into the catalyst during the start-up phase, which is related to the characteristics of the engine itself, and the catalyst supplier cannot provide relevant data. Exemplarily, the maximum oxygen storage capacity can be determined according to the preset catalyst temperature-catalyst aging degree-engine start time-catalyst maximum oxygen storage capacity correspondence (which can be presented in the form of a graph or table). The correspondence can be generated by pre-experimental calibration or simulation calculation, presenting the maximum oxygen storage capacity of the catalyst under different temperatures, aging degrees and engine start times. Specifically, based on the engine start time in the first operating parameter obtained (i.e., the cumulative time from engine start to the current moment), and the catalyst temperature and aging degree (such as the total operating time of the catalyst) in the second operating parameter, the corresponding maximum oxygen storage capacity of the catalyst is determined from the above correspondence.

[0065] Optionally, the maximum oxygen storage capacity of the catalyst in the current state can also be obtained by multiplying the maximum oxygen storage capacity of the catalyst when it leaves the factory by a compensation factor (or adaptive coefficient) that affects the oxygen storage capacity of the catalyst. The maximum oxygen storage capacity of the catalyst when it leaves the factory and the compensation factor that affects the oxygen storage capacity of the catalyst can be provided by the catalyst supplier; the compensation factor reflects the change in the oxygen storage capacity of the catalyst under actual working conditions, which is usually related to factors such as the temperature, aging degree, and engine start time of the catalyst; the maximum oxygen storage capacity of the catalyst when it leaves the factory is measured under standard working conditions or specific experimental conditions, representing the theoretical maximum oxygen storage capacity of the catalyst. After correction by the compensation factor, the maximum oxygen storage capacity of the catalyst in the current working state can be obtained.

[0066] Optionally, determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount includes:

[0067] According to the first oxygen storage amount in the last preset cycle of the catalyst and the second oxygen storage amount increased in the current preset cycle, it is determined that the sum of the first oxygen storage amount and the second oxygen storage amount is the current actual oxygen storage amount of the catalyst.

[0068] Specifically, considering that the sampling of the first operating parameter and the second operating parameter is usually based on the corresponding sampling period (or frequency), the calculation of the first oxygen storage amount and the second oxygen storage amount will also be accumulated or updated based on the corresponding sampling period (recorded as the preset period). In the preset period of current sampling, the newly added oxygen storage amount in the current preset period is calculated according to the first operating parameter of the engine and the second operating parameter of the catalyst (recorded as the second oxygen storage amount), and superimposed on the determined oxygen storage amount of the catalyst in the previous preset period (recorded as the first oxygen storage amount), so as to obtain the current total oxygen storage amount of the catalyst, that is, the current total oxygen storage amount of the catalyst is the sum of the first oxygen storage amount and the second oxygen storage amount. For example, before the engine is started, the oxygen storage of the catalyst is very low or close to zero (negligible); the calculation of the total oxygen storage of the catalyst (or the actual oxygen storage) starts from the time the engine is started, and the second oxygen storage added in the first preset cycle from the time the engine is started is the actual oxygen storage of the catalyst at the end of the first preset cycle, and the actual oxygen storage at the end of the second preset cycle is the sum of the second oxygen storage added in the second preset cycle and the actual oxygen storage at the end of the previous cycle. By accumulating in this way, the actual oxygen storage at the end of each cycle can be determined, and the actual oxygen storage of the catalyst at different times can be tested (determined). Among them, the preset cycle can be set according to the actual data sampling requirements.

[0069] In this way, based on the continuous operating parameter sampling and updating mechanism, the oxygen storage state of the catalyst is monitored and accurately calculated in real time, thereby providing an important reference for the subsequent control strategy of the vehicle control method.

[0070] Optionally, the catalyst includes a first catalyst and a second catalyst, the exhaust system further includes an exhaust pipe, and the exhaust port of the engine, the first catalyst and the second catalyst are sequentially connected through the exhaust pipe.

[0071] Specifically, in order to further improve the effect of emission control and reduce the emission of harmful substances, the exhaust system is provided with a first catalyst and a second catalyst, and the exhaust port of the engine, the first catalyst and the second catalyst are sequentially connected through an exhaust pipe, so that the first catalyst and the second catalyst sequentially convert the harmful gases in the exhaust gas discharged from the engine through the exhaust port. In this way, when the first catalyst fails to fully harmlessly convert the exhaust gas discharged from the engine, the unconverted harmful gases from the first catalyst can still be converted through the second catalyst, thereby improving the exhaust gas purification treatment effect.

[0072] According to the first oxygen storage amount in the last preset cycle of the catalyst and the second oxygen storage amount increased in the current preset cycle, determining the sum of the first oxygen storage amount and the second oxygen storage amount as the current actual oxygen storage amount of the catalyst includes:

[0073] Determine a second oxygen storage amount of the first catalyst according to the amount of oxygen adsorbed and consumed by the first catalyst in a current preset period, and determine a current first total oxygen storage amount of the first catalyst according to the second oxygen storage amount of the first catalyst and the acquired first oxygen storage amount of the first catalyst; determine a second oxygen storage amount of the second catalyst according to the amount of oxygen adsorbed and consumed by the second catalyst in the current preset period, and determine a current second total oxygen storage amount of the second catalyst according to the second oxygen storage amount of the second catalyst and the acquired first oxygen storage amount of the second catalyst;

[0074] The sum of the first total oxygen storage capacity and the second total oxygen storage capacity is determined as the actual oxygen storage capacity.

[0075] Specifically, in the current preset cycle, the amount of oxygen adsorbed by the first catalyst and the amount of oxygen consumed jointly determine the increased oxygen storage of the catalyst (i.e., the second oxygen storage), that is, the second oxygen storage is the difference between the amount of oxygen adsorbed by the first catalyst and the amount of oxygen consumed in the current preset cycle. After determining the second oxygen storage, the sum of the first oxygen storage and the second oxygen storage can be determined as the current total oxygen storage of the first catalyst (recorded as the first total oxygen storage) based on the second oxygen storage and the first oxygen storage of the first catalyst in the previous cycle.

[0076] Similarly, in the current preset cycle, the amount of oxygen adsorbed by the second catalyst and the amount of oxygen consumed jointly determine the increased oxygen storage of the catalyst (i.e., the second oxygen storage), that is, the second oxygen storage of the second catalyst is the difference between the amount of oxygen adsorbed by the second catalyst and the amount of oxygen consumed in the current preset cycle. After determining the second oxygen storage of the second catalyst, the sum of the first oxygen storage and the second oxygen storage can be determined as the current total oxygen storage of the second catalyst (recorded as the second total oxygen storage) based on the second oxygen storage and the first oxygen storage of the second catalyst in the previous cycle.

[0077] Based on the determined first total oxygen storage capacity and the second total oxygen storage capacity, the total actual oxygen storage capacity of all catalysts (i.e., the sum of the first total oxygen storage capacity and the second total oxygen storage capacity) can be obtained, ensuring that the oxygen storage status of all catalysts in the vehicle exhaust system can be accurately measured, thereby providing key data for engine emission control and optimizing emission effects.

[0078] Optionally, before determining that the sum of the first oxygen storage amount and the second oxygen storage amount is the current actual oxygen storage amount of the catalyst according to the first oxygen storage amount in the previous preset cycle of the catalyst and the second oxygen storage amount increased in the current preset cycle, determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes:

[0079] The amount of oxygen adsorbed by the first catalyst during the current preset period is determined based on a first excess air amount entering the first catalyst during the current preset period, a first oxygen adsorption rate of the first catalyst and a first adaptive coefficient; the amount of oxygen consumed by the first catalyst during the current preset period is determined based on a first excess fuel amount entering the first catalyst during the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine.

[0080] Specifically, the amount of oxygen adsorbed by the first catalyst in the current preset cycle can be determined according to the first operating parameter of the engine (including the first excess air amount entering the first catalyst in the current preset cycle) and the second operating parameter of the catalyst (including the first oxygen adsorption rate and the first adaptive coefficient of the first catalyst). For example, the amount of oxygen adsorbed by the first catalyst in the current preset cycle = the first excess air amount * the first oxygen adsorption rate * the first adaptive coefficient. Among them, the first excess air amount is the part of the air amount entering the engine that exceeds the amount required for fuel combustion in the engine, which will be discharged by the engine into the first catalyst. For example, in actual work, when the amount of air supplied to the engine for fuel combustion exceeds the amount of air required for fuel according to the theoretical air-fuel ratio, the excess part enters the first catalyst. The first oxygen adsorption rate is the theoretical ability of the first catalyst to absorb oxygen under the current working conditions per unit time, such as expressed in the amount of oxygen adsorbed per second or per minute; the rate is affected by factors such as the material properties of the catalyst and the catalyst temperature; in some embodiments, the first oxygen adsorption rate can be calibrated according to the characteristics of the first catalyst itself. The first adaptive coefficient is the ratio of the current measured maximum oxygen storage capacity of the first catalyst to the current theoretical maximum oxygen storage capacity, and is used to correct the change in the oxygen storage capacity of the first catalyst under different operating conditions (such as aging, temperature fluctuations). Among them, the current measured maximum oxygen storage capacity of the first catalyst can be determined by measuring the deviation between the intake volume and consumption required for the catalyst to store full oxygen under long-term fuel cut-off conditions; the theoretical maximum oxygen storage capacity of the first catalyst is obtained by looking up the corresponding relationship (diagram or table) based on the material properties and temperature characteristics of the catalyst under ideal conditions. The maximum measured oxygen storage capacity is determined based on the deviation between the estimated intake and consumed air volumes from the time when the engine is cut off from fuel for a long time to the time when the rear oxygen sensor disposed at the outlet of the first catalyst responds (i.e., a corresponding signal change is generated due to the detection of a significant change in oxygen concentration). For example, when the engine is cut off from fuel for a long time, as the oxygen storage process in the first catalyst continues, the oxygen storage capacity of the first catalyst will reach saturation. When the engine is refueled, the oxygen stored in the catalyst will be consumed due to fuel combustion. The total amount of oxygen stored in the catalyst that has been completely consumed can be determined by recording the time interval from the start of refueling to the corresponding reaction of the rear oxygen sensor disposed at the outlet of the first catalyst and the fuel consumption. This is the maximum measured oxygen storage capacity of the first catalyst currently. Since the oxygen adsorption capacity of the catalyst may be affected by environmental factors such as temperature, pressure and exhaust gas composition, as well as its own characteristics such as material properties and degree of aging, the first adaptive coefficient is used as a dynamic adjustment factor for the oxygen adsorption rate according to the current working environment and its own characteristics of the first catalyst, so as to more accurately reflect the actual oxygen adsorption rate of the first catalyst (i.e., the first oxygen adsorption rate*the first adaptive coefficient), thereby facilitating accurate control of vehicle engine emissions.

[0081] The amount of oxygen consumed by the first catalyst in the current preset cycle can be determined based on the first operating parameter of the engine (including the first excess fuel amount entering the first catalyst in the current preset cycle) and the theoretical air-fuel ratio of the fuel. The first excess fuel amount is the unburned or incompletely burned portion of the fuel entering the engine, which enters the first catalyst through the exhaust port of the engine as the first excess fuel amount entering the first catalyst. The theoretical air-fuel ratio is the ratio of the amount of air required for complete combustion of the fuel to the amount of fuel, which is usually determined by the chemical composition and combustion characteristics of the fuel. For example, the theoretical air-fuel ratio of gasoline is usually 14.7:1. According to the theoretical air-fuel ratio, the first excess fuel amount is directly proportional to the amount of oxygen consumed in the first catalyst, which can be specifically expressed as: the amount of oxygen consumed by the first catalyst = the first excess fuel amount * the theoretical air-fuel ratio.

[0082] In some embodiments, the first excess air amount and the first excess fuel amount usually do not exist at the same time. For example, when the actual air-fuel ratio (i.e., the ratio of the mass of the total air intake of the engine to the total fuel intake of the engine) is equal to the theoretical air-fuel ratio (i.e., the mass ratio of air to fuel required for complete combustion of the fuel in the engine), the fuel and oxygen in the air are fully burned, and the first excess air amount and the first excess fuel amount are both 0 or close to 0 (negligible); when the actual air-fuel ratio (i.e., the ratio of the mass of the total air intake of the engine to the total fuel intake of the engine) is less than the theoretical air-fuel ratio (i.e., the mass ratio of air to fuel required for complete combustion of the fuel in the engine), the first excess air amount and the first excess fuel amount are both 0 or close to 0 (negligible); When the actual air-fuel ratio (i.e., the ratio of the mass of the total air intake of the engine to the total fuel intake of the engine) is greater than the theoretical air-fuel ratio (i.e., the mass ratio of the air to the fuel required for complete combustion of the fuel in the engine), the fuel is correspondingly fully burned, the first excess fuel is 0 or approaches 0 (negligible), and there is excess air containing oxygen (i.e., the first excess air).

[0083] The amount of oxygen adsorbed by the second catalyst during the current preset period is determined based on the second excess air amount entering the second catalyst during the current preset period, the second oxygen adsorption rate of the second catalyst and the second adaptive coefficient; the amount of oxygen consumed by the second catalyst during the current preset period is determined based on the second excess fuel amount entering the second catalyst during the current preset period and the theoretical air-fuel ratio corresponding to the fuel used for the engine.

[0084] Specifically, the amount of oxygen adsorbed by the second catalyst in the current preset cycle can be determined according to the first operating parameters of the engine (including the first excess air entering the first catalyst in the current preset cycle) and the second operating parameters of the catalyst (including the second excess air entering the second catalyst in the current preset cycle, the second oxygen adsorption rate of the second catalyst and the second adaptive coefficient). For example, the amount of oxygen adsorbed by the second catalyst in the current preset cycle = the second excess air amount * the second oxygen adsorption rate * the second adaptive coefficient. Among them, the second excess air amount is the part of the first excess air amount entering the first catalyst that is not adsorbed or consumed by the first catalyst, and this part of air will continue to flow to the second catalyst during the exhaust process; the second excess air amount can be determined according to the first excess air amount and the corresponding parameters. The second oxygen adsorption rate is the theoretical ability of the second catalyst to adsorb oxygen under the current working conditions per unit time, such as expressed in the amount of oxygen adsorbed per second or per minute; this rate is affected by factors such as the catalyst material properties and the catalyst temperature; in some embodiments, the second oxygen adsorption rate can be calibrated according to the characteristics of the second catalyst itself. The second adaptive coefficient is the ratio of the current measured maximum oxygen storage capacity of the second catalyst to the current theoretical maximum oxygen storage capacity, and is used to correct the change in the oxygen storage capacity of the second catalyst under different operating conditions (such as aging, temperature fluctuations). Among them, the current measured maximum oxygen storage capacity of the second catalyst can be determined by measuring the deviation between the intake volume and consumption required for the catalyst to store full oxygen under long-term fuel cut-off conditions; the theoretical maximum oxygen storage capacity of the second catalyst is obtained by looking up the corresponding relationship (diagram or table) based on the material properties and temperature characteristics of the second catalyst under ideal conditions. The second adaptive coefficient is used as a dynamic adjustment factor for the oxygen adsorption rate according to the current working environment and its own characteristics of the second catalyst, so as to more accurately reflect the real oxygen adsorption rate of the second catalyst (i.e., the second oxygen adsorption rate*the second adaptive coefficient), so as to facilitate the accurate control of vehicle engine emissions.

[0085] The amount of oxygen consumed by the second catalyst in the current preset cycle can be determined based on the first operating parameter of the engine (including the first excess fuel amount entering the first catalyst in the current preset cycle) and the theoretical air-fuel ratio of the fuel. The second excess fuel amount is the portion of the first excess fuel amount entering the first catalyst that is not consumed in the first catalyst. This portion of fuel will continue to flow to the second catalyst during the exhaust process as the second excess fuel amount entering the second catalyst. According to the theoretical air-fuel ratio, the second excess fuel amount is directly proportional to the amount of oxygen consumed in the second catalyst, which can be specifically expressed as: the amount of oxygen consumed by the second catalyst = the second excess fuel amount * the theoretical air-fuel ratio. In some embodiments, the second excess fuel amount = the first excess fuel amount - the amount of fuel consumed by the first catalyst.

[0086] In some embodiments, based on the reaction between oxygen-containing air and fuel in the first catalyst, the second excess air amount and the second excess fuel amount usually do not exist at the same time. That is, in the first catalyst, when there is more oxygen, the fuel is completely consumed (the remainder is negligible), and the remaining part is excess air (i.e., the second excess air amount); when there is more fuel, the oxygen is completely consumed (the remainder is negligible), and the remaining part is excess fuel (the second excess fuel amount).

[0087] Optionally, determining the amount of oxygen adsorbed by the first catalyst in the current preset period according to a first excess air amount entering the first catalyst in the current preset period, a first oxygen adsorption rate of the first catalyst, and a first adaptive coefficient; determining the amount of oxygen consumed by the first catalyst in the current preset period according to a first excess fuel amount entering the first catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine, before determining the amount of oxygen consumed by the first catalyst in the current preset period, the determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes:

[0088] A first excess air volume is determined based on the total air intake volume of the engine and a first preset coefficient; wherein, if the engine is in a fuel cut-off state, the first preset coefficient is the fuel cut-off rate of the engine; if the engine is not in a fuel cut-off state, the first preset coefficient is the difference between the excess air coefficient and 1, and the ratio of the excess air coefficient; the excess air coefficient is the ratio of the actual air-fuel ratio of the total air intake volume to the theoretical air-fuel ratio, and the actual air-fuel ratio is the ratio of the total air intake volume to the total fuel intake volume of the engine.

[0089] Specifically, the first excess air volume can be determined according to the first operating parameter of the engine (which includes the total air intake volume of the engine and the first preset coefficient), for example, the first excess air volume = total air intake volume * first preset coefficient; wherein, if the engine is in a fuel cut-off state, the first preset coefficient is the fuel cut-off rate (i.e., the fuel cut-off ratio, which is the ratio of the number of cylinders of the engine that are fuel cut-off to the total number of cylinders); if the engine is in a non-fuel cut-off state, the first preset coefficient is the difference λ-1 between the excess air coefficient λ and 1, and the ratio of the excess air coefficient λ (λ-1) / λ=1-1 / λ, wherein λ=actual air-fuel ratio / theoretical air-fuel ratio, the actual air-fuel ratio is the ratio of the mass of the total air intake volume of the engine to the total fuel intake volume of the engine, and the theoretical air-fuel ratio is the mass ratio of air to fuel required for complete combustion of fuel in the engine. In some embodiments, the total air intake volume and the total fuel intake volume of the engine can be directly or indirectly obtained through corresponding monitoring mechanisms (such as air flow meters, intake pressure sensors, intake temperature sensors, etc.).

[0090] In this way, by dynamically adjusting the first preset coefficient according to the fuel cut-off state and the non-fuel cut-off state of the engine, the first excess air volume can be determined in combination with the actual working state, thereby improving the accuracy of the first excess air volume obtained. In the fuel cut-off state, the fuel cut-off cylinder of the engine does not participate in the combustion, and the air entering it will not mix with the fuel, and no harmful gas will be generated due to combustion. Therefore, the first preset coefficient at this time adopts the fuel cut-off rate, that is, only the air flow of the non-fuel cut-off cylinder needs to be considered when determining the first excess air volume. In this way, it is helpful to avoid taking the invalid air flow into the calculation, thereby improving the accuracy of the first excess air volume, so that the air-fuel ratio can be adjusted more accurately when performing emission control, thereby improving the combustion efficiency and reducing the generation of harmful emissions. In the non-fuel cut-off state, the calculation of the first preset coefficient takes into account the excess air coefficient λ, which reflects the relationship between the actual air-fuel ratio and the theoretical air-fuel ratio. Specifically, the excess air coefficient λ represents the ratio of the actual amount of air entering the engine to the amount of air required for the fuel. The value of λ is usually greater than 1, which means that the actual engine intake (i.e., the total air intake) exceeds the amount required for the theoretical air-fuel ratio, thereby ensuring more complete and sufficient combustion. In this case, the first preset coefficient is (λ-1) / λ, so as to eliminate the part that matches the fuel combustion from the total air intake when calculating the first excess air amount. The remaining excess air amount exceeding the amount required for combustion is the first excess air amount.

[0091] The first excess fuel amount is determined based on the total air intake volume of the engine, the second preset coefficient and the theoretical air-fuel ratio; wherein, if the engine is in a fuel-cut state, the second preset coefficient is 0; if the engine is not in a fuel-cut state, the second preset coefficient is the difference between the excess air coefficient and 1, and the ratio of the excess air coefficient.

[0092] Considering that the excess fuel refers to the amount of fuel that enters the engine but is not completely burned according to the theoretical air-fuel ratio, this incompletely burned portion of the fuel is caused by insufficient air required for combustion. Therefore, the key to calculating the excess fuel is to confirm whether there is an excess or insufficient air supply during the combustion process. Specifically, for the first excess fuel, it can be determined according to the first operating parameter of the engine (which includes the total air intake of the engine and the second preset coefficient), for example, the first excess fuel = total air intake * absolute value of the second preset coefficient / theoretical air-fuel ratio. Among them, if the engine is in a fuel-off state (all or part of the cylinders are fuel-off), the proportion of air in the engine is higher, and the fuel in the engine can be completely consumed. At this time, the second preset coefficient is 0, and the first excess fuel is 0. If the engine is in a non-fuel cut-off state, the second preset coefficient is the difference λ-1 between the excess air coefficient λ and 1, and the ratio of the excess air coefficient λ (λ-1) / λ=1-1 / λ, wherein λ=actual air-fuel ratio / theoretical air-fuel ratio, the actual air-fuel ratio is the ratio of the mass of the total air intake of the engine to the total fuel intake of the engine, and the theoretical air-fuel ratio is the mass ratio of air and fuel required for complete combustion of the fuel in the engine; in this way, the first excess fuel amount=total air intake amount*absolute value of the second preset coefficient / theoretical air-fuel ratio=total air intake amount*|1-1 / λ| / theoretical air-fuel ratio=|total air intake amount / theoretical air-fuel ratio-total air intake amount / (λ*theoretical air-fuel ratio)|=|total air intake amount / theoretical air-fuel ratio-total fuel intake amount|, that is, the first excess fuel amount is the absolute value of the difference between the fuel required to be consumed by the total air intake according to the theoretical air-fuel ratio and the actual total fuel intake of the engine.

[0093] Optionally, when λ>1, there is a first excess air amount, and the first excess air amount = total air intake amount * first preset coefficient; when λ<1, there is a first excess fuel amount, and the first excess fuel amount = total air intake amount * absolute value of second preset coefficient / theoretical air-fuel ratio.

[0094] Determining the amount of oxygen adsorbed by the second catalyst in the current preset period according to a second excess air amount entering the second catalyst in the current preset period, a second oxygen adsorption rate of the second catalyst, and a second adaptive coefficient; determining the amount of oxygen consumed by the second catalyst in the current preset period according to a second excess fuel amount entering the second catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine, before determining the amount of oxygen consumed by the second catalyst in the current preset period, the determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount also includes:

[0095] The second excess air amount is determined based on the current first total oxygen storage capacity, maximum oxygen storage capacity and unadsorbed oxygen amount of the first catalyst; wherein the unadsorbed oxygen amount is determined based on the total air intake amount, the fuel cut-off rate and the amount of oxygen adsorbed by the first catalyst in the current preset period.

[0096] Specifically, the second excess air volume can be determined based on the current first total oxygen storage volume, maximum oxygen storage volume and unadsorbed oxygen volume of the first catalyst, for example, the second excess air volume = the first total oxygen storage volume of the first catalyst - the maximum oxygen storage volume of the first catalyst + the unadsorbed oxygen volume of the first catalyst. The first total oxygen storage volume of the first catalyst is the total oxygen storage volume of the first catalyst in the current preset cycle. The maximum oxygen storage volume of the first catalyst is the maximum oxygen storage volume of the first catalyst under the current operating conditions of the first catalyst, wherein the operating conditions include factors that affect the oxygen storage capacity of the first catalyst, such as temperature and catalyst aging degree. The amount of oxygen not adsorbed by the first catalyst is the amount of oxygen in the first excess air volume in the current preset cycle that is not adsorbed by the first catalyst, which can be determined based on the total air intake volume, the fuel cut-off rate and the amount of oxygen adsorbed by the first catalyst in the current preset cycle. For example, the amount of unadsorbed oxygen = first excess air volume - the amount of oxygen adsorbed by the first catalyst in the current preset cycle = first excess air volume - first excess air volume * first oxygen adsorption rate * first adaptive coefficient = first excess air volume * (1-first oxygen adsorption rate * first adaptive coefficient) = total air intake volume * first preset coefficient * (1-first oxygen adsorption rate * first adaptive coefficient).

[0097] A second excess fuel amount is determined according to the first excess fuel amount, a fuel adsorption rate of the first catalyst, and a first adaptive coefficient.

[0098] Specifically, the second excess fuel amount can be determined based on the first excess fuel amount, the fuel adsorption rate of the first catalyst, and the first adaptive coefficient. For example, the second excess fuel amount = the first excess fuel amount - the amount of fuel adsorbed (or consumed) by the first excess fuel amount = the first excess fuel amount - the first excess fuel amount * the fuel adsorption rate of the first catalyst * the first adaptive coefficient. Among them, the fuel adsorption rate of the first catalyst refers to the theoretical value of the adsorption or catalytic reaction efficiency of the first catalyst to the fuel, which can be calibrated according to the characteristics of the catalyst itself. The first adaptive coefficient is used as a compensation factor for dynamic changes in the actual operating environment to correct the deviation between the theoretical fuel adsorption rate of the first catalyst (i.e., the fuel adsorption rate of the first catalyst) and the actual adsorption rate, that is, the actual adsorption rate of the first catalyst = the fuel adsorption rate of the first catalyst * the first adaptive coefficient, while coordinating the relationship between oxygen and fuel consumption, maintaining the consistency of the catalyst adsorption and combustion process, thereby optimizing the performance of the engine emission control system and improving the accuracy of the fuel adsorption and consumption test.

[0099] Optionally, determining the oxygen storage rate of the catalyst according to the actual oxygen storage amount and the maximum oxygen storage amount includes:

[0100] The sum of the current first maximum oxygen storage capacity of the first catalyst and the current second maximum oxygen storage capacity of the second catalyst is determined as the maximum oxygen storage capacity, and the ratio of the actual oxygen storage capacity to the maximum oxygen storage capacity is determined as the oxygen storage rate.

[0101] Based on the fact that the catalyst includes a first catalyst and a second catalyst, the determination of the oxygen storage rate needs to take both the first catalyst and the second catalyst into consideration.

[0102] Specifically, the sum of the current first maximum oxygen storage capacity of the first catalyst and the current second maximum oxygen storage capacity of the second catalyst is taken as the maximum oxygen storage capacity, and the sum of the current first total oxygen storage capacity of the first catalyst and the current second total oxygen storage capacity of the second catalyst is taken as the actual oxygen storage capacity, and the oxygen storage rate is the ratio of the actual oxygen storage capacity to the maximum oxygen storage capacity. By determining the oxygen storage rate, the comprehensive oxygen storage capacity of the first catalyst and the second catalyst is fully reflected, providing a reference basis for the air-fuel ratio adjustment, emission control and catalyst status monitoring of the engine.

[0103] Optionally, the exhaust system further includes a post oxygen sensor disposed on the exhaust pipe, and the post oxygen sensor is located between the first catalyst and the second catalyst.

[0104] Specifically, the vehicle exhaust system includes a first catalyst, a second catalyst, and a rear oxygen sensor disposed therebetween, which is used to detect and monitor the oxygen concentration in the exhaust gas discharged through the first catalyst, and to evaluate the working state of the first catalyst and the emission control effect. In some embodiments, the exhaust system also includes a front oxygen sensor disposed on the exhaust pipe and located between the exhaust port of the engine and the inlet of the first catalyst, which cooperates with the rear oxygen sensor. The front oxygen sensor and the rear oxygen sensor reflect the oxygen concentration in the exhaust gas through electrical signals.

[0105] The vehicle control method further includes:

[0106] When the first operating parameter of the engine, the second operating parameter of the catalyst and the third operating parameter of the rear oxygen sensor meet the preset adaptive coefficient calculation conditions, the current theoretical maximum oxygen storage capacity and the actual maximum oxygen storage capacity of the first catalyst are determined, and the ratio of the actual maximum oxygen storage capacity to the theoretical maximum oxygen storage capacity is determined and updated as the first adaptive coefficient.

[0107] When the first operating parameter of the engine, the second operating parameter of the catalyst and the third operating parameter of the rear oxygen sensor meet the preset adaptive coefficient calculation conditions, the actual maximum oxygen storage capacity is calculated by monitoring the delayed response characteristics of the oxygen concentration signal of the rear oxygen sensor and combining the number of delay cycles. Among them, the preset adaptive coefficient calculation conditions include long-term engine fuel cut-off (which can be determined based on the engine fuel cut-off rate being greater than a certain value and the accumulated intake volume of the engine at this time being greater than a certain value), the engine intake flow rate is less than the corresponding preset value (used to avoid excessive flow rate impacting the first catalyst, causing the first catalyst to be unable to fully convert pollutants in the engine exhaust), the engine speed is less than the corresponding preset value (used to limit the engine operating conditions to a low load or steady state range, and avoid excessive exhaust flow rate caused by high speed, which affects the oxygen storage capacity of the catalyst, oxygen adsorption rate, stability of pollutant full conversion capacity, etc.), the coolant temperature of the engine cooling system is greater than the corresponding preset value (used to ensure that the engine reaches the normal operating temperature and the exhaust temperature is high enough to heat the catalyst and maintain it in the efficient working range), The adaptive deviation of the engine's excess air coefficient λ is within the corresponding controllable range (used to limit the deviation between the actual air-fuel ratio and the theoretical air-fuel ratio, ensuring that the engine's combustion process is close to the theoretical air-fuel ratio, that is, λ is close to 1, thereby providing the first catalyst with suitable exhaust components to avoid emitting too much or too little oxygen, affecting the oxygen storage and catalytic capacity of the first catalyst), the engine intake volume is less than the maximum value (used to control the total air volume entering the engine to avoid excessive oxygen entering the exhaust system due to excessive intake volume, affecting the oxygen storage capacity and reaction efficiency of the catalyst), the engine intake temperature is less than a fixed value (used to avoid abnormal increase in combustion temperature due to excessively high intake temperature, thereby causing overheating of the catalyst or material degradation, affecting oxygen storage performance and catalytic efficiency), the first catalyst is in a steady state (such as the temperature of the first catalyst reaches the operating temperature) and the rear oxygen sensor is working normally. When the preset adaptive coefficient calculation conditions are met, when the rear oxygen sensor monitors that the oxygen concentration is rich, it indicates that the oxygen storage in the first catalyst has been consumed in large quantities (approaching complete consumption). At this time, the maximum oxygen storage capacity of the first catalyst can be calculated based on the fuel consumption and the time interval for refueling to generate a rich signal to the rear oxygen sensor; wherein, the rich monitoring result of the rear oxygen sensor can be used as an enabling condition for the calculation of the first adaptive coefficient, so as to accurately evaluate the oxygen storage performance of the catalyst and make dynamic corrections.Exemplarily, the enabling condition is a pulse amount, that is, the adaptive pulse signal is enabled only when it is determined that the engine has been cut off from fuel for a long time, the first catalyst is operating in a steady state and the rear oxygen sensor has just responded that U_LamBinRe (i.e., the rear oxygen sensor voltage value)>U_HegoRich (i.e., the rear oxygen sensor rich state threshold); when the engine is not cut off from fuel or the rear oxygen sensor is not in a lean state U_LamBinRe>U_HegoLean (i.e., the rear oxygen sensor voltage lean state threshold) and the adaptive enabling has been executed, the subsequent adaptive execution conditions (i.e., the adaptive coefficient calculation process) are triggered.

[0108] Specifically, during the fuel cut-off period, the first catalyst absorbs oxygen until the oxygen storage is saturated, and the oxygen stored in the catalyst will not be directly discharged through the exhaust pipe. Subsequently, when the engine is refueled, fuel combustion begins to consume the oxygen stored in the catalyst, and the oxygen concentration signal of the rear oxygen sensor will respond due to the significant change in oxygen concentration; by recording the time interval (number of delay cycles) from the start of refueling to the signal response of the rear oxygen sensor, the oxygen consumption is calculated in combination with the fuel consumption and the air-fuel ratio, so as to determine the actual maximum oxygen storage capacity of the first catalyst. At the same time, the theoretical maximum oxygen storage capacity of the first catalyst under ideal working conditions is determined by checking the corresponding correspondence or model calculation method, and the ratio of the two is used as the new first adaptive coefficient to update the previously determined first adaptive coefficient to correct the deviation of the catalyst adsorption rate and oxygen storage capacity under actual operating conditions.

[0109] Exemplarily, determining and updating the first adaptive coefficient of the oxygen storage capacity of the first catalyst is carried out in three steps: first, determining whether the preset adaptive coefficient calculation conditions are met, then determining the adaptive intake volume after the delay, and then determining and updating the first adaptive coefficient. Specifically, the first adaptive coefficient will be recalculated only when the preset adaptive coefficient calculation conditions are met, otherwise the first adaptive coefficient remains unchanged. Since the limit point measured after the oxygen sensor reacts after a long period of fuel cut-off is only for the first catalyst, the adaptation is calculated based on the actual measured value of the first catalyst and has nothing to do with the second catalyst. If the oxygen storage capacity of the catalyst remains unchanged, the stored oxygen and the oxygen required for excess fuel are both 0 in the above process; when there is a change, the stored oxygen and the consumed oxygen will deviate, and the actual maximum oxygen storage capacity can be obtained according to the following formula:

[0110] m_OSC1AdpSum=m_OSC1Max+m_OSC1EmptyTot-m_OSC1MinMaxCmp;

[0111] Among them, m_OSC1AdpSum represents the current actual maximum oxygen storage capacity of the first catalyst; m_OSC1Max represents the current theoretical maximum oxygen storage capacity of the first catalyst; m_OSC1EmptyTot represents the oxygen consumed by the first catalyst; m_OSC1MinMaxCmp represents the oxygen stored in the first catalyst;

[0112] Considering that there is a certain delay period from the engine intake to the rear oxygen sensor, the adaptive intake volume after the delay selects the total oxygen storage volume reaching the rear oxygen sensor; the calculated delay period number D_SampleDly is used to select the oxygen storage volume that actually reaches the rear oxygen sensor at this time. The calculation method of the delay period number D_SampleDly is as follows:

[0113] It is determined that under a certain working condition, there is a certain delay period from the fuel injector to the rear oxygen sensor after the fuel is cut off; after the fuel is cut off, a certain amount of rich mixed gas is needed to compensate for the residual exhaust gas in the cylinder and the oxygen content stored in the catalyst. At this time, the cumulative intake volume ∑md_CylPurg*ts is selected to compare with the total air volume md_CylPurg*ts from the fuel injector to the rear oxygen sensor under this working condition to determine the delay period number D_SampleDly. The specific method is to use the formula when the fuel is cut off:

[0114] m_AcumlFlowOK>∑md_CylPurg*ts;

[0115] Among them, m_AcumlFlowOK represents the intake air volume from the injector to the rear oxygen sensor under a certain working condition; md_CylPurg represents the intake air flow; ts represents the scheduling cycle (such as the preset cycle). When the above formula is satisfied, it proves that the air volume entering the engine has not yet reached the rear oxygen sensor. At this time, the delay is counted and accumulated to obtain D_SampleDly; when the above formula is not satisfied, it proves that the air volume entering the engine has reached the rear oxygen sensor. At this time, the delay count stops accumulating and remains at the last count value to obtain the final D_SampleDly;

[0116] Determine and update the first adaptive coefficient. The adaptive calculation can use the first adaptive coefficient determined last time to update the adaptive value this time, that is:

[0117] rt_AdpNew=m_OSC1Max*rt_AdpFilt_DOC / m_OSC1AdpSumDly;

[0118] Wherein, rt_AdpNew represents the updated first adaptive coefficient; m_OSC1Max represents the current theoretical maximum oxygen storage of the first catalyst; rt_AdpFilt_DOC represents the last first adaptive coefficient; m_OSC1AdpSumDly represents the current actual maximum oxygen storage of the first catalyst. In some embodiments, in order to ensure the normal operation of the engine, it is necessary to limit the first adaptive coefficient within a preset range, that is, to limit the maximum and minimum values ​​of the new first adaptive coefficient. If the newly determined first adaptive coefficient is greater than the maximum value, the maximum value is used as the new first adaptive coefficient; and if the newly determined first adaptive coefficient is less than the minimum value, the minimum value is used as the new first adaptive coefficient.

[0119] Optionally, determining a target air-fuel ratio for an engine of the vehicle according to an actual oxygen storage amount and / or an actual oxygen storage rate of a catalyst of an exhaust system of the vehicle that has been acquired, and controlling the engine operation according to the target air-fuel ratio includes:

[0120] When the actual oxygen storage amount is greater than a first preset value or the actual oxygen storage rate is greater than a second preset value, if the engine is in a fuel-cutoff state, a first preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the first preset target air-fuel ratio to achieve fuel-cutoff and deoxygenation of the catalyst; if the engine is in a starting state, a second preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the second preset target air-fuel ratio to achieve starting and deoxygenation of the catalyst.

[0121] Specifically, in order to ensure the best operating state of the catalyst, when the oxygen stored in the catalyst reaches a certain level, deoxygenation is required. Deoxygenation is achieved by enriching the mixture (i.e. reducing the actual air-fuel ratio of the engine) until the rear oxygen sensor responds accordingly and deoxygenation is completed. And the amount of enrichment during deoxygenation needs to be calibrated according to the condition of the vehicle to avoid excessive fuel content in the mixture, resulting in a large amount of particulate matter (such as carbonaceous particles produced by incomplete engine combustion) in the exhaust gas.

[0122] Taking into account the different operating states of the engine, when the engine is in a fuel-off state, and the actual oxygen storage capacity of the first catalyst is greater than the first preset value or the oxygen storage rate is greater than the second preset value, it means that the oxygen storage capacity in the first catalyst is too high, which will affect the efficient operation of the first catalyst. At this time, it is necessary to reduce the actual air-fuel ratio by enriching the mixture to cut off fuel and deoxygenate. Specifically, based on the first preset target air-fuel ratio determined to be less than the current actual air-fuel ratio, the fuel injection amount is adjusted to provide reducing gas, so that the oxygen storage capacity is gradually reduced until the rear oxygen sensor detects that the mixture has turned into an (oxygen) rich state and stops operating, completing fuel-off and deoxygenation. Among them, the first preset value and the second preset value can be set according to actual needs.

[0123] When the engine is in the starting state, and the actual oxygen storage amount of the first catalyst is greater than the first preset value or the oxygen storage rate is greater than the second preset value, it means that the oxygen storage amount in the first catalyst is too high, which will affect the efficient operation of the first catalyst. At this time, it is necessary to reduce the actual air-fuel ratio by enriching the mixed gas to cut off fuel and deoxygenate. Specifically, based on the second preset target air-fuel ratio determined to be less than the current actual air-fuel ratio, the fuel injection amount is adjusted to provide reducing gas, so that the oxygen storage amount is gradually reduced until the rear oxygen sensor detects that the mixed gas has turned into an (oxygen) rich state and stops the operation, completing the fuel cut and deoxygenation.

[0124] It is worth noting that the first preset target air-fuel ratio and the second preset target air-fuel ratio need to be precisely controlled according to the vehicle calibration to avoid incomplete combustion and the generation of particulate matter, while dynamically adjusting to ensure optimal catalyst performance.

[0125] For example, when the oxygen stored in the catalyst reaches a certain level, deoxygenation is required to ensure the optimal operation of the catalyst. Deoxygenation is to enrich the mixture until the rear oxygen sensor responds. The amount of enrichment during deoxygenation needs to be calibrated for the entire vehicle, because an overly rich mixture will cause a large amount of particulate matter in the exhaust. Specifically, the compensation amount can be calculated and combined with the current actual air-fuel ratio of the engine to obtain the target air-fuel ratio, and the first catalyst is deoxygenated accordingly.

[0126] Deoxygenation is divided into fuel cut-off deoxygenation and start-up deoxygenation. When the engine is in the starting state and there is no fuel cut-off or catalytic heating, and the oxygen storage is greater than the minimum compensation value (or limit, i.e., the first preset value), the catalyst deoxygenation compensation is performed during the starting phase; and when there is a fuel cut-off or the oxygen storage is lower than the minimum compensation oxygen storage, the deoxygenation compensation during the starting phase is not performed. Among them, the deoxygenation compensation during the starting phase can be based on the preset oxygen storage-compensation amount (or preset target air-fuel ratio) correspondence relationship, and the corresponding compensation amount (or preset target air-fuel ratio) can be determined according to the current oxygen storage amount.

[0127] When the oxygen storage amount is greater than the deoxygenation limit (i.e., the second preset value), the engine fuel cut occurs, the catalytic heating operation is not performed, and the rear oxygen sensor is not in a rich state, the deoxygenation compensation for fuel cut is performed. The deoxygenation compensation for fuel cut can be obtained by querying the preset corresponding relationship between the oxygen storage amount-engine intake flow-compensation amount (or the preset target air-fuel ratio).

[0128] Optionally, determining a target air-fuel ratio for an engine of the vehicle according to an actual oxygen storage amount and / or an actual oxygen storage rate of a catalyst of an exhaust system of the vehicle that has been acquired, and controlling the engine operation according to the target air-fuel ratio includes:

[0129] In response to an engine shutdown command, if the actual oxygen storage amount is greater than a third preset value or the actual oxygen storage rate is greater than a fourth preset value, a third preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the third preset target air-fuel ratio. When the actual oxygen storage amount is less than or equal to the third preset value, or the actual oxygen storage rate is less than or equal to the fourth preset value, the engine is controlled to shut down.

[0130] Specifically, when receiving the engine shutdown command, if the actual oxygen storage capacity of the catalyst is high, if the engine is directly shut down, the oxygen content in the catalyst may increase (or be excessive), resulting in an increase in nitrogen oxides (NOx) in the exhaust, polluting the environment. To avoid this, the engine needs to continue running for a period of time to eliminate the impact of emissions.

[0131] For example, when the vehicle engine is in a high load condition when receiving the engine shutdown command, it means that the oxygen storage in the catalyst is high, and since the oxygen is continuously stored in the catalyst when the engine is running under high load conditions, if the engine is directly shut down at this time, and there is a situation where the actual oxygen storage of the catalyst is greater than the third preset value or the actual oxygen storage rate is greater than the fourth preset value, it may cause the oxygen accumulated in the catalyst to fail to be consumed in time, thereby generating adverse emissions, especially nitrogen oxides (NOx). Therefore, in this case, the engine needs to continue to run for a period of time so that the oxygen storage can be reduced to a safe level through an appropriate combustion process, thereby reducing NOx emissions and avoiding pollution to the environment. For example, by controlling the actual air-fuel ratio of the engine to be reduced to the third preset target air-fuel ratio, the catalyst is deoxygenated and the oxygen content in the catalyst is reduced until a predetermined safety threshold is reached (such as the actual oxygen storage is less than or equal to the third preset value, or the actual oxygen storage rate is less than or equal to the fourth preset value), the engine can be controlled to shut down. In this way, the emission is guaranteed to meet the corresponding standards, and the operating state of the catalyst is optimized to extend its service life. In some embodiments, when the oxygen storage capacity of the catalyst is greater than the minimum oxygen storage capacity requested for engine operation and is not less than the oxygen storage capacity for shutdown operation, the catalyst deoxygenation compensation coefficient is less than the minimum compensation, and the fuel cut-off rate is less than the minimum fuel cut-off coefficient, if an engine shutdown command is received, the shutdown operation request and the deoxygenation operation flag position 1 are performed, that is, the engine is controlled to continue running and perform the above-mentioned deoxygenation operation.

[0132] Combination Figure 2 As shown, another embodiment of the present invention provides a control device, comprising:

[0133] A control unit is used to determine a target air-fuel ratio for the engine of the vehicle based on an actual oxygen storage amount and / or an actual oxygen storage rate of the catalyst of the exhaust system of the vehicle when the operating state of the engine of the vehicle meets a preset catalyst oxygen storage condition, and control the engine operation based on the target air-fuel ratio.

[0134] The control device of this embodiment is used to implement the above-mentioned vehicle control method. Its advantages over the prior art are the same as the advantages of the above-mentioned vehicle control method over the prior art, which will not be repeated here.

[0135] Combination Figure 3 As shown, another embodiment of the present invention provides a vehicle, including a memory 301 and a processor 302;

[0136] Memory 301, used for storing computer programs;

[0137] The processor 302 is used to implement the above-mentioned vehicle control method when executing the computer program.

[0138] In other words, a vehicle includes a memory 301 and a processor 302 coupled to the memory 301; the memory 301 is configured to store a computer program; the processor 302 is configured to perform the following operations when executing the computer program:

[0139] When the operating state of the vehicle's engine meets the preset catalyst oxygen storage conditions, the target air-fuel ratio of the vehicle's engine is determined based on the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst of the vehicle's exhaust system that have been acquired, and the engine operation is controlled based on the target air-fuel ratio.

[0140] The vehicle of this embodiment can be used to implement the above-mentioned vehicle control method. Its advantages over the prior art are the same as the advantages of the above-mentioned vehicle control method over the prior art, and will not be repeated here.

[0141] Another embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is read and executed by a processor, the above-mentioned vehicle control method is implemented.

[0142] In other words, a non-volatile computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the following operations:

[0143] When the operating state of the vehicle's engine meets the preset catalyst oxygen storage conditions, the target air-fuel ratio of the vehicle's engine is determined based on the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst of the vehicle's exhaust system that have been acquired, and the engine operation is controlled based on the target air-fuel ratio.

[0144] The technical solution of the embodiment of the present invention, in essence or in other words, the part that contributes to the prior art, or the whole or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for making a computer device (which can be a personal computer, server, or network device, etc.) or a processor perform all or part of the steps of the method of the embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0145] The computer-readable storage medium of this embodiment can be used to implement the above-mentioned vehicle control method. Its advantages over the prior art are the same as the advantages of the above-mentioned vehicle control method over the prior art, and will not be repeated here.

[0146] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A vehicle control method, characterized in that: include: When the operating state of the vehicle's engine meets the preset catalyst oxygen storage conditions, the target air-fuel ratio of the vehicle's engine is determined based on the actual oxygen storage amount and / or actual oxygen storage rate of the catalyst of the vehicle's exhaust system that have been acquired, and the engine operation is controlled based on the target air-fuel ratio.

2. The vehicle control method according to claim 1, characterized in that: The catalyst oxygen storage condition includes the engine being in a fuel cut-off state, a lean-burn state or a starting state.

3. The vehicle control method according to claim 1, characterized in that: Determining a target air-fuel ratio for an engine of the vehicle based on the acquired actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and controlling the engine operation based on the target air-fuel ratio includes: According to the first operating parameter of the engine and the second operating parameter of the catalyst that have been acquired, determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount; according to the actual oxygen storage amount, determining the target air-fuel ratio, and controlling the operation of the engine according to the target air-fuel ratio; And / or, based on the first operating parameter and the second operating parameter, determine the current total oxygen storage capacity of the catalyst as the actual oxygen storage capacity, and determine the current maximum oxygen storage capacity of the catalyst; determine the oxygen storage rate of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity; determine the target air-fuel ratio based on the oxygen storage rate, and control the engine operation according to the target air-fuel ratio.

4. The vehicle control method according to claim 3, characterized in that: Determining the current total oxygen storage capacity of the catalyst as the actual oxygen storage capacity includes: According to the first oxygen storage amount of the catalyst in a previous preset cycle and the second oxygen storage amount increased in a current preset cycle, it is determined that the sum of the first oxygen storage amount and the second oxygen storage amount is the current actual oxygen storage amount of the catalyst.

5. The vehicle control method according to claim 4, characterized in that: The catalyst includes a first catalyst and a second catalyst, and the exhaust system also includes an exhaust pipe, and the exhaust port of the engine, the first catalyst and the second catalyst are sequentially connected through the exhaust pipe; The step of determining, based on a first oxygen storage amount of the catalyst in a previous preset cycle and a second oxygen storage amount increased in a current preset cycle, the sum of the first oxygen storage amount and the second oxygen storage amount as the current actual oxygen storage amount of the catalyst comprises: Determine the second oxygen storage amount of the first catalyst according to the amount of oxygen adsorbed and consumed by the first catalyst in a current preset period, and determine the current first total oxygen storage amount of the first catalyst according to the second oxygen storage amount of the first catalyst and the first oxygen storage amount of the first catalyst that has been acquired; determine the second oxygen storage amount of the second catalyst according to the amount of oxygen adsorbed and consumed by the second catalyst in a current preset period, and determine the current second total oxygen storage amount of the second catalyst according to the second oxygen storage amount of the second catalyst and the first oxygen storage amount of the second catalyst that has been acquired; The sum of the first total oxygen storage capacity and the second total oxygen storage capacity is determined as the actual oxygen storage capacity.

6. The vehicle control method according to claim 5, characterized in that: Before determining that the sum of the first oxygen storage amount and the second oxygen storage amount is the current actual oxygen storage amount of the catalyst according to the first oxygen storage amount in the previous preset cycle of the catalyst and the second oxygen storage amount increased in the current preset cycle, the determining that the current total oxygen storage amount of the catalyst is the actual oxygen storage amount further includes: determining the amount of oxygen adsorbed by the first catalyst in the current preset period according to a first excess amount of air entering the first catalyst in the current preset period, a first oxygen adsorption rate of the first catalyst, and a first adaptive coefficient; determining the amount of oxygen consumed by the first catalyst in the current preset period according to a first excess amount of fuel entering the first catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine; The amount of oxygen adsorbed by the second catalyst within the current preset period is determined based on a second excess air amount entering the second catalyst within the current preset period, a second oxygen adsorption rate and a second adaptive coefficient of the second catalyst; the amount of oxygen consumed by the second catalyst within the current preset period is determined based on a second excess fuel amount entering the second catalyst within the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine.

7. The vehicle control method according to claim 6, characterized in that: Before determining the amount of oxygen adsorbed by the first catalyst in the current preset period according to a first excess amount of air entering the first catalyst in the current preset period, a first oxygen adsorption rate of the first catalyst and a first adaptive coefficient; and determining the amount of oxygen consumed by the first catalyst in the current preset period according to a first excess amount of fuel entering the first catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine, the determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes: The first excess air volume is determined according to the total air intake volume of the engine and a first preset coefficient; wherein, if the engine is in a fuel cut-off state, the first preset coefficient is the fuel cut-off rate of the engine; if the engine is not in the fuel cut-off state, the first preset coefficient is the ratio of the difference between the excess air coefficient and 1 to the excess air coefficient; the excess air coefficient is the ratio of the actual air-fuel ratio of the total air intake volume to the theoretical air-fuel ratio, and the actual air-fuel ratio is the ratio of the total air intake volume to the total fuel intake volume of the engine; The first excess fuel amount is determined according to the total air intake amount of the engine, the second preset coefficient and the theoretical air-fuel ratio; wherein, if the engine is in the fuel cut-off state, the second preset coefficient is 0; if the engine is not in the fuel cut-off state, the second preset coefficient is the ratio of the difference between the excess air coefficient and 1 to the excess air coefficient; Before determining the amount of oxygen adsorbed by the second catalyst in the current preset period according to a second excess air amount entering the second catalyst in the current preset period, a second oxygen adsorption rate of the second catalyst and a second adaptive coefficient; and determining the amount of oxygen consumed by the second catalyst in the current preset period according to a second excess fuel amount entering the second catalyst in the current preset period and a theoretical air-fuel ratio corresponding to the fuel used for the engine, the determining the current total oxygen storage amount of the catalyst as the actual oxygen storage amount further includes: Determine the second excess air amount according to the first total oxygen storage amount, the maximum oxygen storage amount and the amount of unabsorbed oxygen of the first catalyst at present; wherein the amount of unabsorbed oxygen is determined according to the total air intake amount, the fuel cut-off rate and the amount of oxygen adsorbed by the first catalyst in a current preset period; The second excess fuel amount is determined according to the first excess fuel amount, the fuel adsorption rate of the first catalyst, and the first adaptive coefficient.

8. The vehicle control method according to claim 5, characterized in that: Determining the oxygen storage rate of the catalyst according to the actual oxygen storage amount and the maximum oxygen storage amount includes: The sum of a current first maximum oxygen storage capacity of the first catalyst and a current second maximum oxygen storage capacity of the second catalyst is determined as the maximum oxygen storage capacity, and the ratio of the actual oxygen storage capacity to the maximum oxygen storage capacity is determined as the oxygen storage rate.

9. The vehicle control method according to claim 6, characterized in that: The exhaust system further includes a rear oxygen sensor disposed on the exhaust pipe, wherein the rear oxygen sensor is located between the first catalyst and the second catalyst; and the vehicle control method further includes: When the first operating parameter of the engine, the second operating parameter of the catalyst and the third operating parameter of the rear oxygen sensor meet the preset adaptive coefficient calculation conditions, the current theoretical maximum oxygen storage capacity and the actual maximum oxygen storage capacity of the first catalyst are determined, and the ratio of the actual maximum oxygen storage capacity to the theoretical maximum oxygen storage capacity is determined and updated as the first adaptive coefficient.

10. The vehicle control method according to any one of claims 1 to 9, characterized in that: Determining a target air-fuel ratio for an engine of the vehicle based on the acquired actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and controlling the engine operation based on the target air-fuel ratio includes: When the actual oxygen storage amount is greater than a first preset value or the actual oxygen storage rate is greater than a second preset value, if the engine is in a fuel-cut state, a first preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the first preset target air-fuel ratio to achieve fuel-cutting and deoxygenation of the catalyst; if the engine is in a starting state, a second preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the second preset target air-fuel ratio to achieve starting deoxygenation of the catalyst.

11. The vehicle control method according to any one of claims 1 to 9, characterized in that: Determining a target air-fuel ratio for an engine of the vehicle based on the acquired actual oxygen storage amount and / or actual oxygen storage rate of a catalyst of an exhaust system of the vehicle, and controlling the engine operation based on the target air-fuel ratio includes: In response to an engine shutdown command, if the actual oxygen storage amount is greater than a third preset value or the actual oxygen storage rate is greater than a fourth preset value, a third preset target air-fuel ratio for the engine is determined, and the engine operation is controlled according to the third preset target air-fuel ratio. When the actual oxygen storage amount is less than or equal to the third preset value, or the actual oxygen storage rate is less than or equal to the fourth preset value, the engine is controlled to shut down.

12. A control device, characterized in that: include: A control unit is used to determine a target air-fuel ratio for the engine of the vehicle based on an actual oxygen storage amount and / or an actual oxygen storage rate of the catalyst of the exhaust system of the vehicle when the operating state of the engine of the vehicle meets a preset catalyst oxygen storage condition, and control the engine operation based on the target air-fuel ratio.

13. A vehicle, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is used to implement the vehicle control method according to any one of claims 1 to 11 when executing the computer program.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the vehicle control method according to any one of claims 1 to 11 is implemented.

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