A method and device for measuring oxygen storage capacity, a vehicle and a storage medium

Abstract

This application provides a method, apparatus, vehicle, and storage medium for measuring oxygen storage capacity. The method includes: when the vehicle's current operating mode is a preset target operating mode, controlling the vehicle's hybrid engine to enter a lean-burn state; in the lean-burn state, oxygen in the exhaust gas is adsorbed by a target substance in the vehicle's catalytic converter; triggering in-cylinder fuel injection, and determining the duration of a target event under the action of the in-cylinder fuel injection; wherein the target event is that the temperature at the rear end of the catalytic converter is higher than the temperature at the front end of the catalytic converter, and the difference between the rear end temperature and the front end temperature is greater than a preset temperature; determining the oxygen storage capacity of the catalytic converter based on the duration. This method simplifies and facilitates the measurement process of the oxygen storage capacity of the catalytic converter.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more specifically, to a method, apparatus, vehicle, and storage medium for measuring oxygen storage capacity in the field of vehicles. Background Technology

[0002] Oxygen Storage Capacity (OSC) is a crucial indicator of the catalyst in aftertreatment systems, playing a significant role in determining the criticality (or aging) of catalysts and in catalyst diagnosis. However, currently, measuring OSC requires disassembling the catalyst from the aftertreatment system and measuring it on specialized equipment, a process that is neither simple nor convenient. Summary of the Invention

[0003] This application provides a method, apparatus, vehicle, and storage medium for measuring oxygen storage capacity, which makes the process of measuring the oxygen storage capacity of a catalytic converter simpler and more convenient.

[0004] In a first aspect, a method for measuring oxygen storage capacity is provided. The method includes: controlling the vehicle's hybrid system to enter a lean-burn state when the vehicle's current operating mode is a preset target operating mode; wherein, in the lean-burn state, oxygen in the exhaust gas is adsorbed by a target substance in the vehicle's catalytic converter; triggering in-cylinder fuel injection, and determining the duration of a target event under the action of the in-cylinder fuel injection; wherein the target event is that the temperature at the rear end of the catalytic converter is higher than the temperature at the front end of the catalytic converter, and the difference between the rear end temperature and the front end temperature is greater than a preset temperature; and determining the oxygen storage capacity of the catalytic converter based on the duration of the event.

[0005] In the above technical solution, by controlling the hybrid engine to enter a lean-burn state under the target operating mode, the oxygen in the exhaust gas is adsorbed by the target substance in the catalyst under lean-burn conditions, meaning the catalyst can store oxygen under lean-burn conditions. Then, the oxygen storage capacity of the catalyst is identified by the oxidation temperature rise characteristics of the catalyst generated by post-injected fuel. Specifically, substances such as CO, HC, PAH, and aldehydes in the post-injected fuel undergo an exothermic oxidation reaction with the oxygen adsorbed by the target substance in the catalyst, resulting in a significant temperature difference between the rear and front ends of the catalyst. The target event is defined as a temperature difference between the rear and front ends of the catalyst exceeding a preset temperature; therefore, the duration of the target event can reflect the oxygen storage capacity of the catalyst to some extent. Thus, the oxygen storage capacity of the catalyst can be determined relatively accurately based on the duration of the target event. Furthermore, this technical solution eliminates the need to remove the catalyst from the vehicle's aftertreatment system; the oxygen storage capacity can be measured directly on the vehicle, making the measurement process simpler and more convenient.

[0006] In conjunction with the first aspect, in some possible implementations, the target operating mode is either a series mode or a parallel mode of the vehicle's hybrid system.

[0007] In the above technical solutions, the exhaust temperature of the hybrid motor is more likely to reach a stable state in either series or parallel mode, thereby improving the accuracy of oxygen storage capacity measurement.

[0008] In conjunction with the first aspect, in some possible implementations, triggering in-cylinder fuel injection includes: controlling the hybrid engine to enter a stoichiometric air-fuel ratio state; and triggering in-cylinder fuel injection in the stoichiometric air-fuel ratio state.

[0009] In the above technical solution, the stoichiometric air-fuel ratio is equivalent to complete combustion of fuel and air, and theoretically, the exhaust gas does not contain oxygen. Therefore, triggering post-injection of fuel in the cylinder under the stoichiometric air-fuel ratio helps to avoid the presence of oxygen in the exhaust gas of the hybrid engine, further preventing the oxygen in the exhaust gas from interfering with the measurement of oxygen storage capacity.

[0010] In conjunction with the first aspect, in some possible implementations, triggering in-cylinder fuel injection includes: determining whether the exhaust temperature of the vehicle's hybrid engine meets a preset condition; wherein the preset condition is that the change in the exhaust temperature of the hybrid engine within a first preset time period is less than a preset change; and triggering in-cylinder fuel injection when the preset condition is met.

[0011] In the above technical solution, when the exhaust temperature of the vehicle's hybrid motor meets the preset conditions, it means that the exhaust temperature of the hybrid motor has entered a stable state. At this time, the in-cylinder fuel injection is triggered, so that the measured front temperature of the catalytic converter is more stable under the action of the in-cylinder fuel injection. This helps to reduce the difference error between the front and rear temperatures of the catalytic converter, thereby improving the accuracy of oxygen storage capacity measurement.

[0012] In conjunction with the first aspect, in some possible implementations, triggering in-cylinder fuel injection includes: determining whether the exhaust temperature of the vehicle's hybrid motor meets a preset condition; wherein the preset condition is that the change in the exhaust temperature of the hybrid motor within a first preset time period is less than a preset change; when it is determined that the preset condition is met, controlling the hybrid motor to enter a stoichiometric air-fuel ratio state; and triggering in-cylinder fuel injection in the stoichiometric air-fuel ratio state.

[0013] The above technical solution can avoid interference from oxygen in the exhaust gas on the measurement of oxygen storage capacity, while reducing the difference error between the front and rear temperatures of the catalyst, thereby improving the accuracy of oxygen storage capacity measurement.

[0014] In conjunction with the first aspect, in some possible implementations, controlling the vehicle's hybrid motor to enter a lean-burn state when the vehicle's current operating mode is a preset target operating mode includes: whenever the vehicle is detected to have traveled a preset mileage, determining whether the vehicle's current operating mode is a preset target operating mode; and when the vehicle's current operating mode is determined to be a preset target operating mode, controlling the vehicle's hybrid motor to enter a lean-burn state.

[0015] In conjunction with the first aspect, in some possible implementations, determining the oxygen storage capacity of the catalyst based on the existence time includes: determining that the catalyst has oxygen storage capacity when the existence time is greater than a second preset duration; and determining that the catalyst does not have oxygen storage capacity when the existence time is less than or equal to the second preset duration.

[0016] In conjunction with the first aspect, in some possible implementations, the second preset duration is greater than or equal to 3 seconds.

[0017] In the above technical solution, considering that for catalytic converters that are about to fail due to aging, i.e. catalytic converters that basically have no oxygen storage capacity, they can only achieve a 3-second "temperature at the rear end is higher than the temperature at the front end by a preset temperature under the action of the back spray". Therefore, using 3 seconds as a standard to measure whether the catalytic converter has oxygen storage capacity is beneficial to accurately determine whether the catalytic converter currently has oxygen storage capacity.

[0018] In conjunction with the first aspect, in some possible implementations, triggering in-cylinder fuel injection includes: triggering in-cylinder fuel injection and controlling the fuel injection to continue for a third preset duration; wherein the third preset duration is longer than the second preset duration.

[0019] In conjunction with the first aspect, in some possible implementations, the preset temperature is determined based on the post-injection amount, and the larger the post-injection amount, the larger the preset temperature.

[0020] Secondly, a device for measuring oxygen storage capacity is provided, comprising: a control module, a triggering module, and a determining module; wherein, the control module is used to control the hybrid engine of the vehicle to enter a lean-burn state when the current operating mode of the vehicle is a preset target operating mode; wherein, in the lean-burn state, oxygen in the exhaust gas is adsorbed by a target substance in the catalytic converter of the vehicle; the triggering module is used to trigger in-cylinder fuel injection and, under the action of the in-cylinder fuel injection, determine the duration of a target event; wherein, the target event is that the temperature at the rear end of the catalytic converter is higher than the temperature at the front end of the catalytic converter, and the difference between the rear end temperature and the front end temperature is greater than a preset temperature; the determining module is used to determine the oxygen storage capacity of the catalytic converter based on the duration of the event.

[0021] In conjunction with the second aspect, in some possible implementations, the target operating mode is either a series mode or a parallel mode of the vehicle's hybrid system.

[0022] In conjunction with the second aspect and the above implementation methods, in some possible implementations, the trigger module is specifically used to control the hybrid engine to enter the stoichiometric air-fuel ratio state; in the stoichiometric air-fuel ratio state, it triggers in-cylinder fuel injection. Alternatively, the trigger module is specifically used to determine whether the exhaust temperature of the vehicle's hybrid engine meets a preset condition; wherein the preset condition is that the change in the exhaust temperature of the hybrid engine within a first preset time period is less than a preset change; if the preset condition is met, it triggers in-cylinder fuel injection. Alternatively, the trigger module is specifically used to determine whether the exhaust temperature of the vehicle's hybrid engine meets a preset condition; when the preset condition is met, it controls the hybrid engine to enter the stoichiometric air-fuel ratio state; in the stoichiometric air-fuel ratio state, it triggers in-cylinder fuel injection.

[0023] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the control module is specifically used to determine whether the current working mode of the vehicle is a preset target working mode whenever the vehicle has traveled a preset mileage; when it is determined that the current working mode of the vehicle is the preset target working mode, the control module controls the hybrid motor of the vehicle to enter a lean-burn state.

[0024] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is specifically used to determine that the catalyst has oxygen storage capacity when the existence time is greater than the second preset duration; and to determine that the catalyst does not have oxygen storage capacity when the existence time is less than or equal to the second preset duration.

[0025] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the second preset duration is greater than or equal to 3 seconds.

[0026] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the triggering module is specifically used to trigger in-cylinder fuel injection and control the fuel injection to continue for a third preset duration; wherein, the third preset duration is longer than the second preset duration.

[0027] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the preset temperature is determined based on the post-injection amount, and the larger the post-injection amount, the larger the preset temperature.

[0028] Thirdly, a vehicle is provided, including a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, causing the electronic device to perform the methods of the first aspect or any possible implementation thereof.

[0029] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0030] Fifthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a vehicle after-treatment system provided in an embodiment of this application;

[0032] Figure 2 This is a schematic flowchart of a method for measuring oxygen storage capacity provided in an embodiment of this application;

[0033] Figure 3 This is a flowchart illustrating another method for measuring oxygen storage capacity provided in an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the structure of an oxygen storage capacity measuring device provided in an embodiment of this application;

[0035] Figure 5 This is a structural schematic diagram of a vehicle provided in an embodiment of this application. Detailed Implementation

[0036] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0037] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0038] As global environmental problems become increasingly severe, emission reduction has become a crucial task for the automotive industry. Hybrid electric vehicles (HEVs), as a new type of vehicle, can reduce both fuel consumption and emissions; therefore, they are expected to remain a mainstream technology in the automotive industry for a considerable period.

[0039] Some functions in the powertrain that require engine power can be achieved through innovative hybrid technology. In hybrid vehicles, the engine's operating point is adjusted based on its performance characteristics. A range with lower fuel consumption is selected as the engine's operating range, determined by engine speed and torque. If the engine is not operating within this range, the electric motor generates electricity and provides assistance, adjusting the engine torque to keep it operating within this economical range, thus reducing emissions and fuel consumption.

[0040] Hybrid systems have several operating modes: Mode 1, pure electric drive: The engine does not operate; the battery powers the electric motor, which drives the wheels. Mode 2, series mode: The engine generates electricity to power the battery, which then powers the electric motor, which drives the wheels. Mode 3, independent engine drive: The battery and electric motor are not powered; the engine drives the entire drive system. Mode 4, parallel mode: The engine drives the drive system while the battery powers the electric motor; the engine, battery, and generator operate in parallel. The engine in a hybrid system can also be called a hybrid motor. Therefore, Mode 2 can be described as follows: The hybrid motor powers the vehicle's battery, which in turn powers the electric motor. Mode 4 can also be described as follows: The hybrid motor powers the drive system while the battery powers the electric motor.

[0041] Oxygen Storage Capacity (OSC) is an important indicator of the catalyst in the aftertreatment system, and it is of great significance for determining the criticality (or aging) of the catalyst and for catalytic converter diagnosis. However, currently, measuring OSC requires removing the catalyst from the aftertreatment system and measuring it on specialized equipment, which is not a simple and convenient process.

[0042] To address the aforementioned technical problems, this application provides a method for measuring oxygen storage capacity. This method can be applied to vehicles with hybrid systems, specifically to the electronic control unit (ECU) in such vehicles.

[0043] To facilitate understanding of the implementation process of the embodiments of this application, the vehicle's after-processing system will be described first. For example... Figure 1As shown, in the aftertreatment system, vehicle exhaust enters through the exhaust valve, passes through the turbocharger, and then flows sequentially through the catalytic converter and the diesel particulate filter (DPF). The catalytic converter can be a lean NOx trap (LNT) or a three-way catalytic converter (TWC). A three-way catalytic converter is a catalytic converter that can simultaneously purify hydrocarbons, carbon monoxide, and nitrogen oxides from vehicle exhaust, reducing most of the pollutants emitted by the engine. The DPF captures carbon particles in the exhaust.

[0044] In this embodiment, it is not necessary to... Figure 1 The catalyst can be easily removed to measure its oxygen storage capacity. The method for measuring the oxygen storage capacity in this embodiment is described below:

[0045] Figure 2 This is a schematic flowchart illustrating a method for measuring oxygen storage capacity provided in an embodiment of this application.

[0046] For example, such as Figure 2 As shown, the method includes:

[0047] Step 201: When the vehicle's current operating mode is the preset target operating mode, control the vehicle's hybrid system to enter a lean-burn state. In this lean-burn state, oxygen in the exhaust gas is adsorbed by the target substance in the vehicle's catalytic converter.

[0048] Step 202: Trigger in-cylinder fuel injection and determine the duration of the target event under the influence of in-cylinder fuel injection. The target event is defined as the temperature at the rear end of the catalytic converter being higher than the temperature at the front end, and the difference between the two temperatures being greater than a preset temperature.

[0049] Step 203: Determine the oxygen storage capacity of the catalyst based on its duration of existence.

[0050] exist Figure 2In the illustrated embodiment, by controlling the hybrid engine to enter a lean-burn state under the target operating mode, oxygen in the exhaust gas is adsorbed by the target substance in the catalyst under lean-burn conditions, meaning the catalyst can store oxygen under lean-burn conditions. Then, the oxygen storage capacity of the catalyst is identified by the oxidation and temperature rise characteristics of the catalyst generated by post-injected fuel. Specifically, substances such as CO, HC, PAH, and aldehydes in the post-injected fuel undergo an exothermic oxidation reaction with the oxygen adsorbed by the target substance in the catalyst, resulting in a significant temperature difference between the rear and front ends of the catalyst. The target event is defined as a temperature difference between the rear and front ends of the catalyst exceeding a preset temperature; therefore, the duration of the target event can reflect the oxygen storage capacity of the catalyst to some extent. Thus, the oxygen storage capacity of the catalyst can be determined relatively accurately based on the duration of the target event. Furthermore, the above technical solution eliminates the need to remove the catalyst from the vehicle's aftertreatment system; the oxygen storage capacity of the catalyst can be measured directly on the vehicle, making the measurement process simpler and more convenient.

[0051] The following is about Figure 2 The specific implementation methods for each step are explained below:

[0052] In step 201, the ECU can first determine the vehicle's current operating mode, which can be the current operating mode of the vehicle's hybrid system. When the current operating mode is determined to be a preset target operating mode, the ECU controls the vehicle's hybrid motor to enter a lean-burn state. The current operating mode of the vehicle may be any of the various operating modes of the hybrid system mentioned above. The target operating mode can be an operating mode that makes it easy for the exhaust temperature of the hybrid motor to reach a stable state, where a stable state can be understood as: the change in exhaust temperature within a certain period of time is less than a preset range. This preset range can be set according to actual needs, aiming to indicate that the change in exhaust temperature is very small within a certain period of time.

[0053] In an exemplary embodiment, the target operating mode is either a series mode or a parallel mode of the vehicle's hybrid system. In the series mode, the vehicle's hybrid motor generates electricity for the vehicle's battery, which in turn drives the vehicle's electric motor. In the parallel mode, the hybrid motor drives the transmission system while the battery powers the electric motor. That is, the target operating mode can be either mode 2 or mode 4 as described above.

[0054] In this embodiment, the exhaust temperature of the hybrid motor is more likely to reach a stable state in both series and parallel modes, thereby improving the accuracy of oxygen storage capacity measurement.

[0055] In an exemplary embodiment, the exhaust temperature of the hybrid motor is more likely to reach a stable state in series mode compared to parallel mode. This is because in series mode, the engine, i.e., the aforementioned hybrid motor, is only used for driving power generation, and therefore the engine's exhaust temperature easily reaches a constant state. Therefore, when the vehicle's current operating mode is determined to be series mode, the vehicle's hybrid motor can be controlled to enter a lean-burn state.

[0056] When a vehicle's hybrid system enters a lean-burn state, oxygen in the exhaust gas is adsorbed by a target substance in the vehicle's catalytic converter. The air-fuel ratio in a lean-burn state is greater than the stoichiometric air-fuel ratio of 14.7:1. The air-fuel ratio is the mass ratio between air and fuel. Therefore, the essence of a lean-burn state is "more air and relatively less fuel," meaning that some oxygen in the air is not burned but exists in the exhaust gas. This oxygen is "temporarily adsorbed" by the target substance in the catalytic converter; this is the so-called oxygen storage method. The target substance can be a chemical substance used for oxygen adsorption, such as cerium (Ce). The chemical reaction for oxygen adsorption can be as follows:

[0057] Ce₂O₃ + 1 / 2O₂ → 2CeO₂

[0058] In an exemplary embodiment, step 101 includes: whenever the vehicle is detected to have traveled a preset mileage, determining whether the vehicle's current operating mode is a preset target operating mode. When it is determined that the vehicle's current operating mode is the preset target operating mode, controlling the vehicle's hybrid motor to enter a lean-burn state. The preset mileage can be set according to actual needs, for example, it can be set to 50 kilometers, 100 kilometers, or 200 kilometers; however, this embodiment does not specifically limit the exact size of the preset mileage. That is, in this embodiment, whenever the vehicle is detected to have traveled a preset mileage, steps 201 to 203 can be executed once, which is beneficial for meeting the actual oxygen storage capacity measurement requirements.

[0059] In step 202, the ECU can trigger in-cylinder fuel injection and, under the action of in-cylinder fuel injection, determine the existence time of the target event. The target event is that the temperature at the rear end of the catalyst is higher than the temperature at the front end of the catalyst, and the difference between the rear end temperature and the front end temperature is greater than a preset temperature.

[0060] In-cylinder fuel injection, after normal engine ignition and injection, the injector injects additional fuel into the cylinder during the piston's downward movement. The purpose of this injection is to allow substances such as CO, HC, PAH, and aldehydes in the injected fuel to undergo an exothermic oxidation reaction with the oxygen adsorbed by Ce in the catalyst. The oxidation reaction formula is as follows:

[0061] CO + 1 / 2O₂ → CO₂

[0062] HC + O2 → CO2 + H2O

[0063] PAH + O2 → CO2 + H2O

[0064] Aldehyde + O2 → CO2 + H2O

[0065] It is understandable that when the catalytic converter has oxygen storage capacity, under the effect of post-fuel injection, the exothermic oxidation reaction occurring inside the catalytic converter will cause the temperature at the rear end of the catalytic converter to be higher than the temperature at the front end for a period of time. In this embodiment, it can be achieved through... Figure 1 The high-temperature sensor 1 at the front end of the catalytic converter measures the front-end temperature, and the high-temperature sensor 2 at the rear end of the catalytic converter measures the rear-end temperature. High-temperature sensors 1 and 2 can respectively return the measured front-end and rear-end temperatures to the ECU, allowing the ECU to determine whether a target event has occurred where the rear-end temperature is higher than the front-end temperature, and the difference between the two temperatures exceeds a preset temperature, and to record the duration of the target event. The preset temperature can be set according to actual needs; this implementation does not impose specific limitations on it.

[0066] In an exemplary embodiment, the preset temperature can be determined based on the amount of fuel injected afterward; the larger the amount of fuel injected, the higher the preset temperature. The amount of fuel injected can be the mass of fuel. Specifically, the preset temperature can be determined based on the mass of fuel injected per cylinder per injection. The larger the mass of fuel injected per cylinder per injection, the higher the preset temperature; conversely, the smaller the mass of fuel injected per cylinder per injection, the lower the corresponding preset temperature. For example, when controlling the injection of 4mg of fuel per cylinder per injection during post-injection, the temperature measured by the high-temperature sensor 2 after the catalytic converter can be more than 100°C higher than the temperature measured by the high-temperature sensor 1 before the catalytic converter. Therefore, in this embodiment, when controlling the injection of 4mg of fuel per cylinder per injection during post-injection, the preset temperature can be set to 100 degrees Celsius. When controlling the injection of more than 4mg of fuel per cylinder per injection during post-injection, the preset temperature can be greater than 100 degrees Celsius.

[0067] In an exemplary embodiment, triggering post-injection of in-cylinder fuel includes: controlling the hybrid engine to enter a stoichiometric air-fuel ratio state. In this stoichiometric air-fuel ratio state, post-injection of in-cylinder fuel is triggered. In this embodiment, this is equivalent to controlling the hybrid engine to enter a stoichiometric air-fuel ratio state before triggering post-injection of in-cylinder fuel, ensuring that the triggering of post-injection of in-cylinder fuel is performed within this stoichiometric air-fuel ratio state. In this stoichiometric air-fuel ratio state, fuel and air are considered to be fully combusted, and theoretically, the exhaust gas does not contain oxygen. Therefore, triggering post-injection of in-cylinder fuel at this stoichiometric air-fuel ratio state helps to avoid the presence of oxygen in the exhaust gas emitted by the hybrid engine, further preventing the oxygen in the exhaust gas from interfering with the measurement of oxygen storage capacity.

[0068] The theoretical air-fuel ratio, or the current air-fuel ratio, is 14.7:1. A theoretical air-fuel ratio of 14.7:1 means that the fuel and air are completely combusted, and theoretically, the exhaust gas contains no oxygen. In reality, even if the exhaust gas contains oxygen, the oxygen content is very low. The purpose of performing subsequent monitoring at the theoretical air-fuel ratio is to minimize the presence of oxygen in the engine's exhaust gas at this time, further preventing oxygen in the exhaust gas from interfering with the monitoring process.

[0069] In an exemplary embodiment, the ECU can control the vehicle's hybrid motor to enter a lean-burn state after a preset time interval, and then control the hybrid motor to enter a stoichiometric air-fuel ratio state. The preset time interval can be set according to actual needs, for example, it can be between 30 and 40 seconds, so that the catalytic converter has sufficient time to store oxygen.

[0070] In an exemplary embodiment, triggering post-injection of in-cylinder fuel includes: determining whether the exhaust temperature of the vehicle's hybrid engine meets a preset condition; wherein the preset condition is that the change in the exhaust temperature of the hybrid engine within a first preset time period is less than a preset change amount; and triggering post-injection of in-cylinder fuel if the preset condition is met. The preset condition indicates that the exhaust temperature of the hybrid engine is currently in a stable state; that is, when it is determined that the exhaust temperature of the hybrid engine is currently in a stable state, post-injection of in-cylinder fuel is triggered.

[0071] The aforementioned first preset duration and preset change amount can be set according to actual needs. They are used to characterize the small change in the exhaust temperature of the hybrid engine within a certain time period, which can be considered as a stable exhaust temperature. For example, the first preset duration can be between 15 and 35 seconds, and the preset change amount can be between 15°C and 35°C. For example, the first preset duration can be 20 seconds, and the preset change amount can be 20°C. However, in this embodiment, the magnitude of the first preset duration and the preset change amount is not specifically limited.

[0072] For example, after the hybrid motor enters a lean-burn state, it can be detected whether the exhaust temperature of the hybrid motor meets a preset condition for the first time. Detecting whether the exhaust temperature of the hybrid motor meets the preset condition for the first time helps to reduce detection time, thereby improving the measurement speed of oxygen storage capacity to a certain extent.

[0073] For example, see Figure 1 When the temperature loss of the exhaust gas from the hybrid motor between the exhaust valve and the high-temperature sensor 1 is negligible, the exhaust temperature of the hybrid motor can also be the temperature measured by the high-temperature sensor 1. Therefore, the above preset condition can be understood as: the change in the front-end temperature of the catalytic converter within the first preset time period is less than the preset change amount.

[0074] For example, see Figure 1When the temperature loss of the exhaust gas from the hybrid motor between the exhaust valve and the high-temperature sensor 1 is not negligible, Figure 1 A temperature sensor can be installed between the exhaust valve and the turbocharger, so that the exhaust temperature of the hybrid motor can be measured through the temperature sensor.

[0075] For example, see Figure 1 The exhaust temperature decay value from the exhaust valve to the high temperature sensor 1 can be calculated based on the distance between the exhaust valve and the high temperature sensor 1 and the unit temperature decay value corresponding to the unit distance. Then, the sum of the temperature value measured by the high temperature sensor 1 and the calculated exhaust temperature decay value is used as the exhaust temperature of the hybrid motor. This allows the engine exhaust temperature to be accurately obtained without adding a temperature sensor.

[0076] In this embodiment, when the exhaust temperature of the vehicle's hybrid motor meets the preset conditions, it indicates that the exhaust temperature of the hybrid motor has entered a stable state. At this time, in-cylinder fuel injection is triggered, so that the measured front temperature of the catalyst is more stable under the action of in-cylinder fuel injection. This helps to reduce the difference error between the front and rear temperatures of the catalyst, thereby improving the accuracy of oxygen storage capacity measurement.

[0077] In an exemplary embodiment, the above-mentioned triggering of in-cylinder fuel injection includes: determining whether the exhaust temperature of the vehicle's hybrid motor meets a preset condition; when it is determined that the preset condition is met, controlling the hybrid motor to enter a stoichiometric air-fuel ratio state; and triggering in-cylinder fuel injection in the stoichiometric air-fuel ratio state.

[0078] In this embodiment, when the exhaust temperature of the vehicle's hybrid motor meets a preset condition, the hybrid motor can be first controlled to enter the stoichiometric air-fuel ratio state. Then, under the condition that the exhaust temperature of the vehicle's hybrid motor meets the preset condition and the hybrid motor has entered the stoichiometric air-fuel ratio state, in-cylinder fuel injection is triggered. This can avoid interference from oxygen in the exhaust gas on the measurement of oxygen storage capacity, while reducing the difference error between the front and rear temperatures of the catalytic converter, thereby improving the accuracy of oxygen storage capacity measurement.

[0079] In step 203, the ECU can determine the oxygen storage capacity of the catalytic converter based on the presence time measured in step 202. The presence time is used to measure whether the catalytic converter has oxygen storage capacity. For example, a longer presence time indicates a better oxygen storage capacity, while a shorter presence time indicates a worse oxygen storage capacity.

[0080] In an exemplary embodiment, step 203 can be implemented by: determining that the catalyst has oxygen storage capacity when the existence time is greater than a second preset duration; and determining that the catalyst does not have oxygen storage capacity when the existence time is less than or equal to the second preset duration. The second preset duration can be set according to actual needs and can be used to determine whether the catalyst has oxygen storage capacity.

[0081] The inventors of this application discovered through research that for catalytic converters that are about to fail due to aging, i.e., catalytic converters that may not have the ability to store oxygen, they can only achieve a 3-second "temperature at the rear end is higher than the temperature at the front end by a preset temperature under the action of the back spray". Therefore, in this embodiment, the second preset duration can be greater than or equal to 3 seconds. Using 3 seconds as a standard for measuring whether the catalytic converter has the ability to store oxygen is beneficial for accurately determining whether the catalytic converter currently has the ability to store oxygen.

[0082] In an exemplary embodiment, the above-mentioned triggering of in-cylinder fuel post-injection includes: triggering in-cylinder fuel post-injection and controlling the fuel post-injection to continue for a third preset duration, the third preset duration being longer than a second preset duration. The third preset duration can be set according to actual needs. For example, the third preset duration can be the second preset duration plus the time required for substances such as CO, HC, PAH, and aldehydes in the post-injection material to react with oxygen and flow into the catalyst. This allows sufficient time for the substances such as CO, HC, PAH, and aldehydes in the post-injection material to undergo an exothermic oxidation reaction with the oxygen adsorbed by Ce in the catalyst, which to some extent helps improve the accuracy of oxygen storage capacity measurement.

[0083] In one possible implementation, the third preset duration can be between 10 and 30 seconds. For example, the third preset duration can be set to 20 seconds; however, this embodiment does not specifically limit the value of the third preset duration.

[0084] In an exemplary embodiment, assuming the preset temperature is 100°C, the first preset duration is 20 seconds, the preset change amount is 20°C, the preset mileage is 100 kilometers, the second preset duration is 3 seconds, and the third preset duration is 20 seconds, under the above numerical conditions, whenever the vehicle travels 100 kilometers, the following can be executed: Figure 3 Steps 301 to 307 are as follows:

[0085] Step 301: When it is determined that the vehicle has entered the "engine-driven power generation, at which time the engine is used to generate electricity for the battery, and then the battery drives the motor to work" mode, control the hybrid motor to enter the lean combustion state.

[0086] In other words, once the vehicle is confirmed to be in the aforementioned series mode, the hybrid motor is controlled to enter a lean-burn state (air-fuel ratio > 14.7:1).

[0087] Step 302: Check if the "exhaust temperature change does not exceed 20°C in 20 seconds" occurs for the first time. If yes, proceed to step 303; otherwise, continue with step 302.

[0088] In other words, the system checks whether the exhaust temperature of the hybrid motor meets the preset conditions. If it does, it means that the exhaust temperature of the hybrid motor has entered a stable state, and the system proceeds to step 304. Otherwise, it means that the exhaust temperature of the hybrid motor has not yet entered a stable state, and the system can continue to execute step 302.

[0089] Step 303: Control the hybrid engine to enter the stoichiometric air-fuel ratio state (air-fuel ratio = 14.7:1).

[0090] Step 304: After the fuel injection is triggered, determine the time t during which the temperature at the rear end of the catalytic converter is more than 100°C higher than the temperature at the front end, 20 seconds after the fuel injection is triggered.

[0091] In other words, the in-cylinder fuel injection is triggered 20 seconds later, and the existence time t of the target event is determined under the action of the in-cylinder fuel injection.

[0092] Step 305: Determine if t is greater than 3 seconds. If yes, proceed to step 306; otherwise, proceed to step 307.

[0093] Step 306: Determine that the catalyst has oxygen storage capacity.

[0094] Step 307: Determine that the catalyst does not have oxygen storage capacity.

[0095] In this embodiment, the advantage of the series mode of the hybrid system, where the exhaust temperature is more likely to reach a stable state, is utilized. After the vehicle's hybrid system enters series mode, the hybrid motor is controlled to enter a lean-burn state to allow the catalytic converter in the aftertreatment system to store oxygen. Then, once the exhaust temperature is determined to be stable, the hybrid motor is controlled to enter a 14.7:1 theoretical air-fuel ratio state to "avoid oxygen interference." The oxygen storage capacity of the catalytic converter is identified by the oxidation and heating characteristics of the catalytic converter caused by post-injected fuel. In this embodiment, the oxygen storage capacity of the catalytic converter can be accurately measured directly on the vehicle, aiming for simplicity and practicality, without having to remove the catalytic converter from the vehicle.

[0096] Figure 4 This is a schematic diagram of the structure of an oxygen storage capacity measuring device provided in an embodiment of this application.

[0097] For example, such as Figure 4As shown, the device includes: a control module 401, a triggering module 402, and a determination module 403; wherein, the control module 401 is used to control the hybrid engine of the vehicle to enter a lean-burn state when the current operating mode of the vehicle is a preset target operating mode; wherein, in the lean-burn state, oxygen in the exhaust gas is adsorbed by a target substance in the catalytic converter of the vehicle; the triggering module 402 is used to trigger in-cylinder fuel injection and, under the action of in-cylinder fuel injection, determine the duration of a target event; wherein, the target event is that the temperature at the rear end of the catalytic converter is higher than the temperature at the front end of the catalytic converter, and the difference between the rear end temperature and the front end temperature is greater than a preset temperature; the determination module 403 is used to determine the oxygen storage capacity of the catalytic converter based on the duration of the event.

[0098] In one possible implementation, the target operating mode is either the series mode or the parallel mode of the vehicle's hybrid system.

[0099] In one possible implementation, the trigger module 402 is specifically used to control the hybrid engine to enter the stoichiometric air-fuel ratio state; in the stoichiometric air-fuel ratio state, it triggers in-cylinder fuel injection.

[0100] In one possible implementation, the trigger module 402 is specifically used to determine whether the exhaust temperature of the vehicle's hybrid motor meets a preset condition; wherein, the preset condition is that the change in the exhaust temperature of the hybrid motor within a first preset time period is less than a preset change amount; if it is determined that the preset condition is met, in-cylinder fuel injection is triggered.

[0101] In one possible implementation, the trigger module 402 is specifically used to determine whether the exhaust temperature of the vehicle's hybrid motor meets a preset condition; when it is determined that the preset condition is met, the hybrid motor is controlled to enter the stoichiometric air-fuel ratio state; and in the stoichiometric air-fuel ratio state, in-cylinder fuel injection is triggered.

[0102] In one possible implementation, the control module 403 is specifically used to determine whether the current operating mode of the vehicle is a preset target operating mode whenever the vehicle has traveled a preset mileage; when the current operating mode of the vehicle is determined to be the preset target operating mode, the control module 403 controls the hybrid motor of the vehicle to enter a lean-burn state.

[0103] In one possible implementation, the determining module 403 is specifically used to determine that the catalyst has oxygen storage capacity when the existence time is greater than a second preset duration; and to determine that the catalyst does not have oxygen storage capacity when the existence time is less than or equal to the second preset duration.

[0104] In one possible implementation, the second preset duration is greater than or equal to 3 seconds.

[0105] In one possible implementation, the trigger module 402 is specifically used to trigger in-cylinder fuel injection and control the fuel injection to continue for a third preset duration; wherein the third preset duration is longer than the second preset duration.

[0106] In one possible implementation, the preset temperature is determined based on the amount of fuel injected afterward; the larger the amount of fuel injected afterward, the higher the preset temperature.

[0107] Figure 5 This is a structural schematic diagram of a vehicle provided in an embodiment of this application.

[0108] For example, such as Figure 5 As shown, the vehicle includes a memory 501 and a processor 502, wherein the memory 501 stores executable program code, and the processor 502 is used to call and execute the executable program code to perform a method for measuring oxygen storage capacity.

[0109] This embodiment can divide the vehicle into functional modules according to the above method example. For example, each module can correspond to a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0110] When each functional module is divided according to its corresponding function, the vehicle may include: a control module, a triggering module, and a determination module, etc. It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0111] The vehicle provided in this embodiment is used to perform the above-described method for measuring oxygen storage capacity, and therefore can achieve the same effect as the above-described implementation method.

[0112] When using integrated units, the vehicle may include a processing module and a storage module. The processing module is used to control and manage the vehicle's actions. The storage module supports the vehicle in executing program code and data.

[0113] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits as disclosed in this application. The processor may also be a combination of computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and microprocessors, etc., and the storage module may be a memory.

[0114] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a method for measuring oxygen storage capacity in the above embodiment.

[0115] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement a method for measuring oxygen storage capacity as described in the above embodiment.

[0116] In addition, the vehicle provided in the embodiments of this application may specifically be a chip, component or module. The vehicle may include a connected processor and a memory. The memory is used to store instructions. When the vehicle is running, the processor may call and execute the instructions to make the chip execute a method for measuring oxygen storage capacity in the above embodiments.

[0117] In this embodiment, the vehicle, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects of the corresponding methods provided above, and will not be repeated here.

[0118] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0119] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0120] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for measuring oxygen storage capacity, characterized in that, include: When the vehicle's current operating mode is the preset target operating mode, the vehicle's hybrid system is controlled to enter a lean-burn state; wherein, in the lean-burn state, oxygen in the exhaust gas is adsorbed by the target substance in the vehicle's catalyst, and the target operating mode is the series mode or parallel mode of the vehicle's hybrid system. Trigger in-cylinder fuel injection, and determine the duration of a target event under the action of the in-cylinder fuel injection; wherein, the target event is that the temperature at the rear end of the catalyst is higher than the temperature at the front end of the catalyst, and the difference between the temperature at the rear end and the temperature at the front end is greater than a preset temperature; The oxygen storage capacity of the catalyst is determined based on the duration of its existence.

2. The method according to claim 1, characterized in that, The triggering of in-cylinder fuel injection includes: controlling the hybrid engine to enter the stoichiometric air-fuel ratio state; Under the aforementioned theoretical air-fuel ratio condition, in-cylinder fuel injection is triggered afterward; or, Determine whether the exhaust temperature of the vehicle's hybrid motor meets a preset condition; wherein the preset condition is that the change in the exhaust temperature of the hybrid motor within a first preset time period is less than a preset change amount. If the preset conditions are met, in-cylinder fuel injection is triggered. or, Determine whether the exhaust temperature of the vehicle's hybrid motor meets a preset condition; wherein the preset condition is that the change in the exhaust temperature of the hybrid motor within a first preset time period is less than a preset change amount. When the preset conditions are met, the hybrid engine is controlled to enter the stoichiometric air-fuel ratio state; Under the theoretical air-fuel ratio condition, in-cylinder fuel injection is triggered.

3. The method according to claim 1, characterized in that, When the vehicle's current operating mode is a preset target operating mode, controlling the vehicle's hybrid motor to enter a lean-burn state includes: Whenever the vehicle is detected to have traveled a preset mileage, it is determined whether the vehicle's current operating mode is the preset target operating mode. When the current operating mode of the vehicle is determined to be the preset target operating mode, the hybrid motor of the vehicle is controlled to enter a lean-burn state.

4. The method according to claim 1, characterized in that, Determining the oxygen storage capacity of the catalyst based on the duration of existence includes: When the duration of existence is greater than the second preset duration, it is determined that the catalyst has oxygen storage capacity. If the duration of existence is less than or equal to the second preset duration, it is determined that the catalyst does not have oxygen storage capacity.

5. The method according to claim 4, characterized in that, The second preset duration is greater than or equal to 3 seconds.

6. The method according to claim 4 or 5, characterized in that, The triggering of in-cylinder fuel injection includes: Trigger in-cylinder fuel injection and control the fuel injection to continue for a third preset duration; wherein the third preset duration is longer than the second preset duration.

7. The method according to any one of claims 1 to 5, characterized in that, The preset temperature is determined based on the amount of fuel injected after the injection; the larger the amount of fuel injected after the injection, the higher the preset temperature.

8. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 7.

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