Engine control method, device, vehicle and storage medium
By calculating the oxygen storage capacity coefficient of the catalytic converter and compensating for the target air-fuel ratio, the engine's fuel cut-off is delayed and the fuel injection quantity is increased. This solves the problem of high emissions in hybrid vehicles during fuel cut-off and fuel supply recovery, improves the catalytic converter's conversion efficiency, and reduces fuel consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGZHOU AUTOMOBILE GROUP CO LTD
- Filing Date
- 2023-07-06
- Publication Date
- 2026-05-19
AI Technical Summary
Hybrid vehicles emit significant amounts of fuel during the process of engine fuel cut-off and fuel supply restoration, which is difficult to control effectively with existing technologies.
By calculating the oxygen storage capacity coefficient of the catalytic converter, querying the target air-fuel ratio compensation, controlling the engine to delay fuel cut-off or enter fuel cut-off mode, and increasing the fuel injection quantity after the fuel supply is restored, the catalytic converter is neutralized and its conversion efficiency is improved.
It reduces engine emissions during fuel cut-off and fuel supply recovery, improves catalytic converter efficiency, and reduces fuel consumption.
Smart Images
Figure CN116950787B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, specifically to an engine control method, device, vehicle, and storage medium. Background Technology
[0002] Currently, most hybrid vehicles control the timing of engine fuel cut-off via a vehicle controller. Because both gasoline and electric power are available, the vehicle switches between the two power sources during operation. In this power mode, the engine's fuel cut-off and restart cycles are more frequent than in pure gasoline vehicles, increasing the difficulty of emission control. Currently, emissions are relatively high when fuel supply is restored after a fuel cut-off. Summary of the Invention
[0003] One object of this application is to provide an engine control method, device, vehicle, and storage medium that reduces vehicle emissions.
[0004] According to one aspect of the embodiments of this application, an engine control method is provided, the method comprising:
[0005] In response to the engine fuel cut-off command, the current oxygen storage capacity coefficient of the catalyst is calculated based on the actual oxygen storage capacity and the maximum oxygen storage capacity of the catalyst.
[0006] Based on the oxygen storage capacity coefficient, query the target air-fuel ratio compensation required for oxygen removal from the catalyst.
[0007] Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, the engine is controlled to delay fuel cut-off or enter fuel cut-off condition.
[0008] After the engine is restarted and fuel supply is restored, the fuel injection quantity is increased according to the target air-fuel ratio compensation.
[0009] According to one aspect of the embodiments of this application, an engine control device is provided, the device comprising:
[0010] The response module is used to respond to the engine fuel cut-off command and calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity of the catalyst.
[0011] The query module is used to query the target air-fuel ratio compensation required for oxygen removal from the catalyst according to the oxygen storage capacity coefficient.
[0012] The fuel cut-off module is used to control the engine to delay fuel cut-off or enter fuel cut-off mode based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation.
[0013] The fuel injection module is used to increase the fuel injection quantity according to the target air-fuel ratio after the engine is restarted and fuel supply is restored.
[0014] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0015] In response to the engine fuel cut-off command, the maximum oxygen storage capacity of the catalyst is obtained according to the operating conditions of the catalyst.
[0016] Based on the engine's operating conditions, calculate the amount of excess oxygen flowing through the catalytic converter before and after engine start-up;
[0017] The actual oxygen storage capacity is calculated based on the amount of excess oxygen and the rate at which the excess oxygen is absorbed by the catalyst.
[0018] The current oxygen storage capacity coefficient of the catalyst is calculated based on the actual oxygen storage capacity and the maximum oxygen storage capacity.
[0019] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0020] Based on the engine shutdown time before startup, calculate the first excess oxygen flowing through the catalyst during the shutdown process;
[0021] Calculate the excess oxygen coefficient and excess fuel coefficient based on the air-fuel ratio after engine start-up;
[0022] Based on the intake air volume, the excess oxygen coefficient, and the excess fuel coefficient under the non-fuel-cut-off condition after engine start-up, calculate the second excess oxygen quantity and the excess fuel quantity under the non-fuel-cut-off condition.
[0023] Based on the intake air volume under the fuel cut-off condition after engine start-up, set the excess air coefficient for the fuel cut-off condition.
[0024] The excess oxygen amount flowing through the catalyst before and after engine start-up is set based on the first excess oxygen amount, the second excess oxygen amount, the excess fuel amount, and the excess air coefficient.
[0025] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0026] Obtain the voltage value of the post-oxygen sensor connected to the catalyst;
[0027] If the voltage value is greater than the voltage threshold, the oxygen storage capacity of the catalyst is corrected to a preset value to obtain the corrected oxygen storage capacity of the catalyst.
[0028] If the voltage value is less than or equal to the voltage threshold, then the actual oxygen storage capacity is set to the corrected catalyst oxygen storage capacity.
[0029] The value of the actual oxygen storage is updated based on the corrected oxygen storage capacity of the catalyst.
[0030] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0031] The catalyst temperature is obtained and filtered to obtain the filtered catalyst temperature.
[0032] The degree of aging of the catalyst is calculated based on the exhaust flow rate entering the catalyst during oscillation control, the detection value of the oxygen sensor before the catalyst, and the detection value of the oxygen sensor after the catalyst.
[0033] Query the temperature correction value corresponding to the filtered catalyst temperature, and query the aging correction value corresponding to the aging degree;
[0034] Based on the temperature correction value and the aging correction value, the maximum oxygen storage capacity of the catalyst at the factory is corrected to obtain the maximum oxygen storage capacity of the catalyst.
[0035] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0036] The engine-associated first temperature detection group, the catalyst-associated second temperature detection group, and the engine speed are obtained.
[0037] If the oxygen storage capacity coefficient is less than the oxygen storage capacity threshold, and each temperature in the first detection temperature group is in the corresponding first temperature range, each temperature in the second detection temperature group is in the corresponding second temperature range, and the engine speed is less than the speed threshold, then query the target angle corresponding to the engine speed.
[0038] Adjust the valve overlap angle to the target angle.
[0039] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0040] If the oxygen storage capacity coefficient is greater than the maximum value of the reference capacity coefficient range, and the target air-fuel ratio compensation is less than the air-fuel ratio compensation threshold, then it is detected that the fuel cut-off of the engine needs to be delayed.
[0041] If the oxygen storage capacity coefficient is less than the minimum value of the reference capacity coefficient range, or the target air-fuel ratio compensation is greater than or equal to the air-fuel ratio compensation threshold, then it is detected that there is no need to delay the fuel cut-off of the engine.
[0042] If the oxygen storage capacity coefficient is within the range of the reference capacity coefficient, then obtain the set state of whether the fuel cut-off needs to be delayed, and maintain the state.
[0043] Depending on whether a delayed fuel cut-off is required, the engine can be controlled to either delay fuel cut-off or directly enter the fuel cut-off state.
[0044] According to one aspect of the embodiments of this application, a vehicle is provided, including: one or more processors; and a storage device for storing one or more programs, which, when executed by the one or more processors, cause the vehicle to implement the methods provided in the various optional implementations described above.
[0045] According to one aspect of the embodiments of this application, a computer program medium is provided, on which computer-readable instructions are stored, which, when executed by a computer's processor, cause the computer to perform the methods provided in the various optional implementations described above.
[0046] According to one aspect of the embodiments of this application, a computer program product or computer program is provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the methods provided in the various optional implementations described above.
[0047] In the technical solution provided in this application embodiment, in response to an engine fuel cut-off command, the current oxygen storage capacity coefficient of the catalyst is calculated based on the actual and maximum oxygen storage capacity of the catalyst. The target air-fuel ratio compensation required for oxygen removal from the catalyst is then queried according to the oxygen storage capacity coefficient. Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, the engine is controlled to delay fuel cut-off or enter a fuel cut-off state. When the engine needs to cut off fuel, the engine is controlled to delay fuel cut-off or enter a fuel cut-off state based on the oxygen storage capacity coefficient of the catalyst and the target air-fuel ratio compensation required for oxygen removal from the catalyst. During the delayed fuel cut-off process, fuel injection can continue, which can neutralize the catalyst. After the fuel supply is restored, fuel injection is further increased through the target air-fuel ratio compensation factor, further improving the conversion efficiency of the catalyst during the engine start-up phase, thereby reducing emissions.
[0048] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.
[0049] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description
[0050] The above and other objectives, features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.
[0051] Figure 1 A schematic flowchart of an engine control method according to an embodiment of this application is shown.
[0052] Figure 2 A schematic flowchart of an engine control method according to an embodiment of this application is shown.
[0053] Figure 3 A schematic diagram of the structure of a three-way catalytic converter sensor is shown.
[0054] Figure 4 A schematic diagram showing the change of space-fuel ratio over time under the oscillation control of a three-way catalytic converter is shown.
[0055] Figure 5 A schematic flowchart of an engine control method according to an embodiment of this application is shown.
[0056] Figure 6 A schematic diagram of an engine control device according to an embodiment of this application is shown.
[0057] Figure 7 A schematic diagram of the structure of a vehicle according to an embodiment of this application is shown. Detailed Implementation
[0058] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided to make the description of this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The drawings are merely illustrative of this application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.
[0059] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more exemplary embodiments. Numerous specific details are provided in the following description to give a full understanding of exemplary embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced with one or more specific details omitted, or other methods, components, steps, etc., can be employed. In other instances, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.
[0060] Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.
[0061] Figure 1 A flowchart illustrating an engine control method according to an embodiment of this application is shown. The method includes the following steps:
[0062] Step S101: In response to the engine fuel cut-off command, calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity of the catalyst.
[0063] The engine fuel cut-off command is an instruction that instructs the engine to enter a fuel cut-off condition. Actual oxygen storage capacity refers to the actual oxygen storage capacity currently detected by the catalytic converter, while maximum oxygen storage capacity refers to the theoretically maximum oxygen storage capacity that the catalytic converter can support. The oxygen storage capacity coefficient can be calculated periodically and updated over time.
[0064] In one embodiment, the current oxygen storage capacity coefficient of the catalyst is obtained as follows: In response to an engine fuel cut-off command, a preset maximum oxygen storage capacity associated with the catalyst is acquired, along with the amount of oxygen flowing through the catalyst when the engine stops, the amount of oxygen entering the catalyst during engine fuel cut-off, and the excess oxygen and excess fuel entering the catalyst during oscillation control in the absence of fuel cut-off during delayed fuel cut-off. Based on the aforementioned oxygen and excess fuel amounts, the actual oxygen storage capacity is calculated, and the current oxygen storage capacity coefficient of the catalyst is calculated based on the actual and maximum oxygen storage capacities. Using this method, the current oxygen storage capacity coefficient of the catalyst can be obtained in real time, and the obtained coefficient accurately reflects the current oxygen storage capacity of the catalyst.
[0065] Step S102: Based on the oxygen storage capacity coefficient, query the target air-fuel ratio compensation required for oxygen removal from the catalyst.
[0066] Target air-fuel ratio compensation refers to the air-fuel ratio that needs to be compensated. It can be used to indicate the amount of fuel injection required to restore fuel supply after engine start-up. If the oxygen storage capacity coefficient is too high, the air-fuel ratio may be too high, and fuel injection is needed to reduce the air-fuel ratio and achieve oxygen removal.
[0067] Step S103: Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, control the engine to delay fuel cut-off or enter fuel cut-off condition.
[0068] The oxygen storage capacity coefficient and the target air-fuel ratio compensation can be detected. When both the oxygen storage capacity coefficient and the target air-fuel ratio compensation are high, the engine needs to delay fuel cut-off, and oscillation control is implemented during the delayed fuel cut-off process. When the oxygen storage capacity coefficient or the target air-fuel ratio compensation is low, delayed fuel cut-off is not necessary. In this case, the engine can immediately enter the fuel cut-off condition by combining the detection results to control the engine's delayed fuel cut-off, i.e., neutralizing the catalytic converter before cutting off fuel, or not delaying fuel cut-off to further accelerate the entry into the fuel cut-off condition, thereby reducing emissions.
[0069] Step S104: After the engine is restarted and fuel supply is restored, increase the fuel injection quantity according to the target air-fuel ratio compensation.
[0070] In one embodiment, after the engine is restarted and fuel supply is restored, the target air-fuel ratio compensation can be recalculated and updated, and the fuel injection quantity can be increased according to the updated target air-fuel ratio compensation to enrich the fuel. As a result, the catalytic converter conversion efficiency is high and the fuel injection quantity is reduced after the engine is started again.
[0071] Using the above method, when the engine needs to cut off fuel, the engine can delay fuel cut-off or enter fuel cut-off mode based on the oxygen storage capacity coefficient of the catalyst and the target air-fuel ratio compensation required to clean the catalyst. During the delayed fuel cut-off process, fuel injection can continue, which can neutralize the catalyst. After the fuel supply is restored, the fuel injection is further increased by the target air-fuel ratio compensation factor, which further improves the conversion efficiency of the catalyst during the engine start-up phase, thereby reducing emissions.
[0072] In one embodiment, controlling the engine to delay fuel cut-off or enter fuel cut-off mode based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation includes: if the oxygen storage capacity coefficient is greater than the maximum value of the reference capacity coefficient range and the target air-fuel ratio compensation is less than the air-fuel ratio compensation threshold, then it is detected that the engine needs to delay fuel cut-off; if the oxygen storage capacity coefficient is less than the minimum value of the reference capacity coefficient range, or the target air-fuel ratio compensation is greater than or equal to the air-fuel ratio compensation threshold, then it is detected that the engine does not need to delay fuel cut-off; if the oxygen storage capacity coefficient is within the reference capacity coefficient range, then a pre-set state of whether fuel cut-off needs to be delayed is obtained and maintained; based on the state of whether fuel cut-off needs to be delayed, the engine is controlled to delay fuel cut-off or directly enter fuel cut-off mode.
[0073] The reference capability coefficient range is the range of capability coefficients that produce a lag effect when switching between delayed fuel cut-off and fuel cut-off. It includes a minimum value and a maximum value. If the oxygen storage capacity coefficient is between the minimum and maximum values, the original state of whether or not fuel cut-off is delayed is maintained, avoiding frequent switching between delayed fuel cut-off and fuel cut-off. If the oxygen storage capacity coefficient is greater than the maximum value, it indicates that the catalytic converter has a large oxygen storage capacity and excess oxygen. If the engine is started again and the catalytic converter is not properly neutralized, the conversion efficiency of the catalytic converter will be relatively low. If the oxygen storage capacity coefficient is less than the minimum value, it indicates that the oxygen storage capacity of the catalytic converter is relatively small. In addition, the air-fuel ratio compensation threshold can also be set to a smaller value to avoid frequent delayed fuel cut-off if the air-fuel ratio compensation threshold is set too high.
[0074] The target air-fuel ratio compensation is a negative number, such as -0.1. If the target air-fuel ratio compensation is less than the air-fuel ratio compensation threshold, then the absolute value of the target air-fuel ratio compensation is relatively high, which can be considered as a relatively high air-fuel ratio compensation required for oxygen purification.
[0075] Using the above method can reduce vehicle emissions and also has a delay effect between delayed fuel cut-off and fuel cut-off.
[0076] In one embodiment, during the process of delaying fuel cutoff of the engine, the oxygen storage capacity coefficient and the target air-fuel ratio compensation are continuously calculated and updated, and the system continuously checks whether delayed fuel cutoff is necessary based on the updated oxygen storage capacity coefficient and target air-fuel ratio compensation. If delayed fuel cutoff is required, oscillation control continues and the system continues to check whether delayed fuel cutoff is necessary until it is detected that delayed fuel cutoff is not necessary, at which point the system initiates the fuel cutoff condition to cut off the engine's fuel supply.
[0077] This method, which involves neutralizing the catalyst before cutting off the fuel supply, can reduce emissions.
[0078] In one embodiment, after controlling the engine to delay fuel cut-off or enter fuel cut-off condition based on the oxygen storage capacity coefficient and target air-fuel ratio compensation, the method further includes: acquiring a first detection temperature group associated with the engine, a second detection temperature group associated with the catalytic converter, and the engine speed; if the oxygen storage capacity coefficient is less than the oxygen storage capacity threshold, and each temperature in the first detection temperature group is in the corresponding first temperature range, each temperature in the second detection temperature group is in the corresponding second temperature range, and the engine speed is less than the speed threshold, then querying the target angle corresponding to the engine speed; and adjusting the valve overlap angle according to the target angle.
[0079] The first temperature detection group contains data related to engine temperatures, including one or more detection temperatures such as engine coolant temperature, engine oil temperature, intake air temperature, and ambient temperature. The second temperature detection group contains data related to the catalytic converter, such as catalytic converter temperature. The first temperature range is defined as the temperature range required within the first temperature detection group when the valve overlap angle needs to be reduced under fuel cut-off conditions. The oxygen storage capacity threshold is a threshold calibrated to evaluate oxygen storage capacity, determined with the aim of determining whether the valve overlap angle needs to be reduced under fuel cut-off conditions. If the oxygen storage capacity coefficient is less than this threshold, further testing is conducted using other parameters to determine whether the function of reducing the valve overlap angle under fuel cut-off conditions is triggered; otherwise, the function of reducing the valve overlap angle under fuel cut-off conditions is not triggered.
[0080] When the first temperature detection group includes multiple detection temperatures, the first temperature range can include temperature ranges corresponding to each detection temperature. For example, the temperature range corresponding to engine coolant temperature is the range above a certain coolant temperature threshold, the temperature range corresponding to intake air temperature is the range above a certain intake air temperature threshold, and the temperature range corresponding to ambient temperature is the range above a certain ambient temperature threshold. The second temperature range may include, for example, the temperature range corresponding to catalytic converter temperature, which can be the range below a certain catalytic converter temperature threshold. The target angle can be obtained by looking up a table using the variable valve timing of the intake and exhaust valves and the engine speed. The target angle is the valve overlap angle that needs to be adjusted. Based on the target angle, the valve overlap angle is further reduced from the current valve overlap angle.
[0081] If the oxygen storage capacity coefficient is greater than or equal to the oxygen storage capacity threshold, or if any temperature in the first detection temperature group is not in the corresponding first temperature range, or if any temperature in the second detection temperature group is not in the corresponding second temperature range, or if the engine speed is greater than or equal to the speed threshold, then the original valve overlap angle is maintained.
[0082] This method reduces the amount of oxygen in the catalytic converter during frequent starts and stops in hybrid vehicles, preventing increased fuel injection during the next start-up and thus saving fuel. Furthermore, it improves the catalytic converter's conversion efficiency after the next start-up, reducing emissions.
[0083] Figure 2 A flowchart illustrating an engine control method according to an embodiment of this application is shown. The method includes:
[0084] Step S201: In response to the engine fuel cut-off command, obtain the maximum oxygen storage capacity of the catalytic converter based on the catalytic converter's operating conditions.
[0085] The catalytic converter's operating conditions include its temperature, the temperature detected by the upstream oxygen sensor connected to the catalytic converter, the temperature detected by the downstream oxygen sensor connected to the catalytic converter, and the exhaust flow rate entering the catalytic converter. By combining these operating conditions, the maximum oxygen storage capacity of the current catalytic converter can be determined.
[0086] In one embodiment, obtaining the maximum oxygen storage capacity of the catalytic converter based on its operating conditions includes: obtaining the catalytic converter temperature and filtering the catalytic converter temperature to obtain a filtered catalytic converter temperature; calculating the aging degree of the catalytic converter based on the exhaust flow rate entering the catalytic converter during oscillation control, the detection value of the oxygen sensor before the catalytic converter, and the detection value of the oxygen sensor after the catalytic converter; querying the temperature correction value corresponding to the filtered catalytic converter temperature and querying the aging correction value corresponding to the aging degree; and correcting the factory maximum oxygen storage capacity of the catalytic converter based on the temperature correction value and the aging correction value to obtain the maximum oxygen storage capacity of the catalytic converter.
[0087] Filtering aims to make the catalytic converter temperature more accurate; methods such as median filtering are used. After filtering the catalytic converter, a temperature correction value corresponding to the catalytic converter temperature is obtained by looking up a table. The catalytic converter temperature and the temperature correction value are positively correlated. Combining the exhaust flow rate entering the catalytic converter during oscillation control, the values of the pre-catalytic converter oxygen sensor and the post-catalytic converter oxygen sensor, the degree of aging is calculated. The pre-catalytic converter oxygen sensor is a linear sensor, and the post-catalytic converter oxygen sensor is a switchable sensor.
[0088] like Figure 3 A schematic diagram of a three-way catalytic converter sensor is shown, which includes a catalyst, a gasline particulate filter (GPF), a pre-oxygen linear sensor, and a post-oxygen switch sensor.
[0089] like Figure 4 As shown, Figure 4 This diagram illustrates the change in air-fuel ratio over time when the three-way catalytic converter is oscillating and controlled. The aging level is determined by comparing the currently calculated area Arich and area Alean with the Arich and Alean calculated at the factory. Lambda is the excess air coefficient. The aging correction value corresponding to the aging level is then queried. The maximum oxygen storage capacity of the catalytic converter at the factory is multiplied by the aging correction value and the temperature correction value to obtain the current maximum oxygen storage capacity of the catalytic converter.
[0090] Using the above method, the current maximum oxygen storage capacity can be calculated, resulting in a more accurate maximum oxygen storage capacity.
[0091] Step S202: Calculate the amount of excess oxygen flowing through the catalytic converter before and after engine start-up, based on the engine's operating conditions.
[0092] In one embodiment, the excess oxygen flowing through the catalyst before and after engine start-up is calculated based on the engine's operating conditions. This includes: calculating a first excess oxygen flowing through the catalyst during the shutdown process based on the engine's shutdown time before start-up; calculating an excess oxygen coefficient and an excess fuel coefficient based on the air-fuel ratio after engine start-up; calculating a second excess oxygen and excess fuel under non-fuel-cut-off conditions based on the intake air volume, excess oxygen coefficient, and excess fuel coefficient after engine start-up; setting an excess air coefficient under fuel-cut-off conditions based on the intake air volume; and setting the excess oxygen flowing through the catalyst before and after engine start-up based on the first excess oxygen, second excess oxygen, excess fuel, and excess air coefficient.
[0093] Before engine start, the excess oxygen entering the catalytic converter during the shutdown process is calculated based on the shutdown time. After engine start, the operation is divided into fuel cut-off and non-fuel cut-off conditions. In the non-fuel cut-off condition, the intake air volume between each two fuel cut-off cycles is obtained by multiplying the intake air flow rate by the timing interval, and the excess oxygen M entering the catalytic converter is obtained by multiplying the intake air volume by the excess oxygen coefficient. Ox The scheduling time is the time interval between two consecutive intake flow rate detections, which can be regarded as the time interval of intake flow rate change, for example, set to 10ms.
[0094] When the air-fuel ratio is 1, no excess oxygen is produced after combustion in the cylinder. The excess oxygen coefficient F Ox Defined as:
[0095]
[0096] Wherein, AFR is the air-fuel ratio. In open-loop control of pre-oxygen, the target air-fuel ratio is selected as the air-fuel ratio, while in closed-loop control, the actual air-fuel ratio is selected as the air-fuel ratio. The excess oxygen coefficient must not be lower than 0.
[0097] Under fuel cut-off conditions, the excess air coefficient is the intake air volume M between two fuel cut-off cycles. OxFc In non-fuel-cutoff operation, the intake air volume between two fuel cutoffs is obtained by multiplying the intake air flow rate by the cutoff time. The excess fuel amount M entering the catalytic converter is obtained by multiplying the intake air volume by the excess fuel coefficient. Fuel When the air-fuel ratio is 1, no excess fuel is produced after combustion in the cylinder, and the excess fuel coefficient F Fuel Defined as:
[0098]
[0099] Specifically, in open-loop pre-oxygen control, the target air-fuel ratio is selected as the air-fuel ratio (AFR), while in closed-loop control, the actual air-fuel ratio is selected as the AFR. Under fuel cut-off conditions, the excess fuel coefficient is 0.
[0100] Step S203: Calculate the actual oxygen storage capacity based on the amount of excess oxygen and the rate at which the excess oxygen is absorbed by the catalyst.
[0101] Assuming that when the engine is cut off from fuel and not started, excess oxygen enters the catalytic converter and is depleted by the catalytic converter at a fixed rate V. Ox1 During absorption, when the engine is operating under oscillation control without fuel cut-off, excess oxygen enters the catalytic converter and is absorbed by the catalytic converter at a fixed rate V. Ox2 Absorption, excess fuel enters the catalytic converter and is absorbed at a rate of V. Fuel Oxygen is stored inside the absorption catalytic converter, where V Fuel This information was obtained by looking up the table based on the air-fuel ratio and intake airflow.
[0102] The method for calculating the oxygen storage capacity of the catalytic converter is as follows:
[0103] OSC=M OxInt ×V Ox1 +∫(M Ox ×V Ox2 +M OxFc ×V Ox1 -M Fuel ×V Fuel );
[0104] After power-off, the OSC is stored in a electrically erasable programmable read-only memory.
[0105] Using the above method, the oxygen storage capacity of the catalyst under the current condition can be obtained in real time.
[0106] In one embodiment, after calculating the actual oxygen storage capacity based on the amount of excess oxygen and the rate at which the excess oxygen is absorbed by the catalyst, the method further includes: obtaining the voltage value of the post-oxygen sensor connected to the catalyst; if the voltage value is greater than a voltage threshold, correcting the catalyst oxygen storage capacity to a preset value to obtain the corrected catalyst oxygen storage capacity; if the voltage value is less than or equal to the voltage threshold, setting the actual oxygen storage capacity to the corrected catalyst oxygen storage capacity; and updating the value of the actual oxygen storage capacity based on the corrected catalyst oxygen storage capacity.
[0107] The calculated catalytic converter oxygen storage capacity can be further corrected based on the voltage value detected by the post-oxygen sensor. When the post-oxygen sensor voltage exceeds a threshold, the catalytic converter oxygen storage capacity is reset to 0, resulting in the corrected catalytic converter oxygen storage capacity. If the post-oxygen sensor voltage does not exceed the threshold, the calculated catalytic converter oxygen storage capacity is set as the corrected oxygen storage capacity. The post-oxygen sensor is a switch-type oxygen sensor.
[0108] Using the above method makes the actual oxygen storage more accurate.
[0109] Step S204: Calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity.
[0110] In one embodiment, the catalyst oxygen storage capacity is the ratio of the corrected catalyst oxygen storage capacity to the current maximum catalyst oxygen storage capacity.
[0111] In one embodiment, the oxygen storage capacity of the catalyst can be determined by subtracting the actual oxygen storage capacity from the maximum oxygen storage capacity. This difference is negatively correlated with the oxygen storage capacity. The smaller the difference, the closer the actual oxygen storage capacity is to the maximum oxygen storage capacity, and the greater the oxygen storage capacity. Conversely, the larger the difference, the greater the deviation of the actual oxygen storage capacity from the maximum oxygen storage capacity, and the smaller the oxygen storage capacity.
[0112] Step S205: Based on the oxygen storage capacity coefficient, query the target air-fuel ratio compensation required for oxygen removal from the catalyst.
[0113] Step S206: Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, control the engine to delay fuel cut-off or enter fuel cut-off condition.
[0114] Step S207: After the engine is restarted and fuel supply is restored, increase the fuel injection quantity according to the target air-fuel ratio compensation.
[0115] Figure 5 A schematic flowchart of an engine control method according to an embodiment of this application is shown.
[0116] The method includes:
[0117] Step S301: Calculate the maximum oxygen storage capacity of the catalyst.
[0118] The catalytic converter temperature correction factor is obtained by querying the catalytic converter temperature after median filtering. The aging level is then determined by combining the exhaust flow rate entering the catalytic converter during closed-loop oscillation control of the oxygen sensor, the value of the linear oxygen sensor before the catalytic converter, and the value of the two-point oxygen sensor after the catalytic converter. The aging level correction factor is then queried. Finally, the current maximum oxygen storage capacity of the catalytic converter is obtained by multiplying the aging level correction factor, the catalytic converter oxygen storage temperature correction factor, and the factory-set maximum oxygen storage capacity.
[0119] Step S302: Calculate the oxygen storage capacity coefficient of the catalyst.
[0120] The excess oxygen flowing through the catalytic converter consists of three parts: the portion of oxygen entering the catalytic converter when the engine is stopped, the portion entering the catalytic converter during engine fuel cut-off, and the portion of excess oxygen and excess fuel entering the catalytic converter during oscillation control while the engine is not cut off. The sum of these three parts yields the catalytic converter's oxygen storage capacity. This capacity is then corrected to obtain the corrected catalytic converter oxygen storage capacity. Dividing the corrected catalytic converter oxygen storage capacity by the current maximum catalytic converter oxygen storage capacity yields the catalytic converter oxygen storage capacity coefficient.
[0121] Step S303: Calculate the required enrichment compensation for neutralizing the oxygen storage in the catalyst.
[0122] Once the catalytic converter's oxygen storage capacity coefficient is greater than the capacity coefficient threshold and the engine has started, the target air-fuel ratio compensation factor required for catalytic converter oxygen removal is obtained by looking up a table based on the catalytic converter's oxygen storage capacity coefficient. Fuel injection is then increased according to the target air-fuel ratio compensation factor. As air-fuel ratio compensation, i.e., fuel injection, continues, the catalytic converter's oxygen storage capacity coefficient continuously decreases. When the catalytic converter's oxygen storage capacity coefficient falls below the capacity coefficient threshold, the catalytic converter oxygen removal target air-fuel ratio compensation process is terminated, fuel injection stops, and the target air-fuel ratio compensation factor is reset to zero.
[0123] In one embodiment, when the catalyst heating or GPF active regeneration is set to a lean target air-fuel ratio, the catalyst oxygen-removal target air-fuel ratio compensation is discontinued and the factor is reset to zero to avoid affecting the catalyst heating and GPF active regeneration functions.
[0124] Step S304: Delay fuel cut-off or direct fuel cut-off for the catalyst.
[0125] The catalyst delayed fuel cut-off request is triggered when the following conditions are met simultaneously: the catalyst oxygen clearing target air-fuel ratio compensation factor is less than a certain threshold a; the catalyst oxygen storage capacity coefficient is greater than a certain threshold b.
[0126] If the above conditions are not met simultaneously, such as the catalytic converter's oxygen-removing target air-fuel ratio compensation factor being greater than or equal to threshold 'a', then the catalytic converter's delayed fuel cut-off request will not be triggered, and fuel cut-off will begin directly. If the catalytic converter's oxygen-removing target air-fuel ratio compensation factor is greater than threshold 'a', then it is necessary to further determine whether the catalytic converter's oxygen storage capacity coefficient is within the interval [c, b], where c is the threshold less than b. If it is within this interval, then it is checked whether delayed fuel cut-off has already been activated. If delayed fuel cut-off has already been activated, then the delayed fuel cut-off continues; if delayed fuel cut-off has not been activated, then the state of no delayed fuel cut-off is maintained, and fuel cut-off begins immediately if delayed fuel cut-off has not been activated. If the target air-fuel ratio compensation factor is greater than or equal to threshold 'a', and the catalytic converter's oxygen storage capacity coefficient is less than threshold 'c', then the delayed fuel cut-off request will not be triggered, and the engine will be controlled to enter the fuel cut-off condition.
[0127] Step S305: Reduce the valve overlap angle under fuel cut-off conditions.
[0128] Because hybrid vehicles frequently start and stop, to reduce the amount of oxygen entering the catalytic converter during fuel cut-off, and to prevent increased fuel consumption due to increased fuel injection from neutralizing the catalytic converter during the next start-up, the function of reducing the valve overlap angle under fuel cut-off conditions is triggered when the following conditions are met simultaneously: fuel cut-off indicator activated; catalytic converter oxygen storage capacity coefficient less than a threshold; engine oil temperature within a certain threshold range; catalytic converter temperature less than a threshold; coolant temperature greater than a threshold; intake air temperature greater than a threshold; ambient temperature greater than a threshold; engine speed less than a threshold. After the above conditions are met and the function of reducing the valve overlap angle under fuel cut-off conditions is activated, the target angles of the variable valve timing (VVT) for the intake and exhaust valves are obtained from tables based on the engine speed, and the intake valve overlap angle is reduced according to the target angles.
[0129] By adopting the above method, taking advantage of the dual power options of engine and electric motor in hybrid vehicles, the fuel cut-off of the engine is delayed without affecting drivability. That is, the fuel is cut off after neutralizing the catalytic converter and the amount of oxygen entering the catalytic converter is controlled at the time of fuel cut-off. After the next start-up, the catalytic converter has high conversion efficiency and the amount of fuel injected is reduced.
[0130] Figure 6 A schematic diagram of an engine control device according to an embodiment of this application is shown. The device includes:
[0131] The response module 401 is used to respond to the engine fuel cut-off command and calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity of the catalyst.
[0132] Query module 402 is used to query the target air-fuel ratio compensation required for oxygen removal from the catalyst according to the oxygen storage capacity coefficient.
[0133] The fuel cut-off module 403 is used to control the engine to delay fuel cut-off or enter fuel cut-off condition based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation.
[0134] The fuel injection module 404 is used to increase the amount of fuel injected according to the target air-fuel ratio after the engine is restarted and fuel supply is restored.
[0135] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0136] In response to the engine fuel cut-off command, the maximum oxygen storage capacity of the catalytic converter is obtained based on the catalytic converter's operating conditions;
[0137] Calculate the amount of excess oxygen flowing through the catalytic converter before and after engine start-up, based on the engine's operating conditions.
[0138] The actual oxygen storage capacity is calculated based on the amount of excess oxygen and the rate at which the excess oxygen is absorbed by the catalyst.
[0139] Calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity.
[0140] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0141] In response to the engine fuel cut-off command, the maximum oxygen storage capacity of the catalytic converter is obtained based on the catalytic converter's operating conditions;
[0142] Calculate the amount of excess oxygen flowing through the catalytic converter before and after engine start-up, based on the engine's operating conditions.
[0143] The actual oxygen storage capacity is calculated based on the amount of excess oxygen and the rate at which the excess oxygen is absorbed by the catalyst.
[0144] Calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity.
[0145] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0146] Obtain the voltage value of the post-oxygen sensor connected to the catalytic converter;
[0147] If the voltage value is greater than the voltage threshold, the oxygen storage capacity of the catalyst is corrected to the preset value to obtain the corrected oxygen storage capacity of the catalyst.
[0148] If the voltage value is less than or equal to the voltage threshold, the actual oxygen storage capacity is set to the corrected catalytic converter oxygen storage capacity.
[0149] Update the actual oxygen storage value based on the corrected catalytic converter oxygen storage value.
[0150] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0151] The catalyst temperature is obtained and filtered to obtain the filtered catalyst temperature.
[0152] The degree of aging of the catalyst is calculated based on the exhaust flow rate entering the catalyst during oscillation control, the detection value of the oxygen sensor before the catalyst, and the detection value of the oxygen sensor after the catalyst.
[0153] Query the temperature correction value corresponding to the filtered catalyst temperature, and query the aging correction value corresponding to the aging degree;
[0154] Based on the temperature correction value and the aging correction value, the maximum oxygen storage capacity of the catalyst is corrected to obtain the maximum oxygen storage capacity of the catalyst.
[0155] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0156] Acquire the first temperature group associated with the engine, the second temperature group associated with the catalytic converter, and the engine speed;
[0157] If the oxygen storage capacity coefficient is less than the oxygen storage capacity threshold, and each temperature in the first detection temperature group is in the corresponding first temperature range, each temperature in the second detection temperature group is in the corresponding second temperature range, and the engine speed is less than the speed threshold, then query the target angle corresponding to the engine speed.
[0158] Adjust the valve overlap angle to the target angle.
[0159] In some embodiments of this application, based on the above technical solutions, the device is configured as follows:
[0160] If the oxygen storage capacity coefficient is greater than the maximum value of the reference capacity coefficient range, and the target air-fuel ratio compensation is less than the air-fuel ratio compensation threshold, then it is detected that the engine needs to delay fuel cut-off.
[0161] If the oxygen storage capacity coefficient is less than the minimum value of the reference capacity coefficient range, or the target air-fuel ratio compensation is greater than or equal to the air-fuel ratio compensation threshold, then it is detected that there is no need to delay the fuel cut-off of the engine.
[0162] If the oxygen storage capacity coefficient is within the reference capacity coefficient range, then obtain the set state of whether the fuel cut-off needs to be delayed and maintain the state.
[0163] Depending on whether a delayed fuel cut-off is required, the engine can be controlled to either delay the fuel cut-off or directly enter the fuel cut-off state.
[0164] The following is for reference. Figure 7 To describe the vehicle 50 according to an embodiment of this application. Figure 7 The vehicle 50 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.
[0165] like Figure 7 As shown, vehicle 50 is represented in the form of a general-purpose computing device. The components of vehicle 50 may include, but are not limited to: at least one processing unit 510, at least one storage unit 520, and a bus 530 connecting different system components (including storage unit 520 and processing unit 510).
[0166] The storage unit stores program code, which can be executed by the processing unit 510 to perform the steps described in the explanatory section of this specification, according to various exemplary embodiments of the present application. For example, the processing unit 510 can perform actions such as... Figure 1 The steps shown are as follows.
[0167] Storage unit 520 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 5201 and / or cache memory 5202, and may further include a read-only memory (ROM) 5203.
[0168] Storage unit 520 may also include a program / utility 5204 having a set (at least one) program module 5205, such program module 5205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.
[0169] Bus 530 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.
[0170] Vehicle 50 can also communicate with one or more external devices 600 (e.g., keyboard, pointing device, Bluetooth device, etc.), one or more devices that enable a user to interact with vehicle 50, and / or any device that enables vehicle 50 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 550, which is connected to display unit 540. Furthermore, vehicle 50 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 560. As shown, network adapter 560 communicates with other modules of vehicle 50 via bus 530. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with vehicle 50, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.
[0171] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, portable hard drive, etc.) or on a network, including several instructions to cause a vehicle (which may be a hybrid vehicle) to execute the method according to the embodiments of this application.
[0172] In an exemplary embodiment of this application, a computer-readable storage medium is also provided, on which computer-readable instructions are stored, which, when executed by a computer's processor, cause the computer to perform the methods described in the above method embodiments.
[0173] According to one embodiment of this application, a program product for implementing the methods in the above-described method embodiments is also provided. This program product may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of this application is not limited thereto. In this document, a readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.
[0174] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0175] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.
[0176] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.
[0177] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages such as JAVA and C++, and conventional procedural programming languages such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).
[0178] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.
[0179] Furthermore, although the steps of the method in this application are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.
[0180] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, portable hard drive, etc.) or on a network, including several instructions to cause a vehicle (which may be a hybrid vehicle) to execute the method according to the embodiments of this application.
[0181] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the appended claims.
Claims
1. An engine control method, characterized in that, The method includes: In response to the engine fuel cut-off command, the current oxygen storage capacity coefficient of the catalyst is calculated based on the actual oxygen storage capacity and the maximum oxygen storage capacity of the catalyst. Based on the oxygen storage capacity coefficient, query the target air-fuel ratio compensation required for oxygen removal from the catalyst. Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, the engine is controlled to delay fuel cut-off or enter fuel cut-off condition. When the oxygen storage capacity coefficient is greater than the capacity coefficient threshold and the engine has started, the target air-fuel ratio compensation factor required for oxygen removal from the catalyst is queried based on the oxygen storage capacity coefficient; the fuel injection quantity is increased according to the target air-fuel ratio compensation factor; when the oxygen storage capacity coefficient is less than the capacity coefficient threshold, fuel injection is stopped and the target air-fuel ratio compensation factor is reset to zero.
2. The method according to claim 1, characterized in that, In response to the engine fuel cut-off command, the current oxygen storage capacity coefficient of the catalytic converter is calculated based on its actual and maximum oxygen storage capacity, including: In response to the engine fuel cut-off command, the maximum oxygen storage capacity of the catalyst is obtained according to the operating conditions of the catalyst. Based on the engine's operating conditions, calculate the amount of excess oxygen flowing through the catalytic converter before and after engine start-up; The actual oxygen storage capacity is calculated based on the amount of excess oxygen and the rate at which the excess oxygen is absorbed by the catalyst. The current oxygen storage capacity coefficient of the catalyst is calculated based on the actual oxygen storage capacity and the maximum oxygen storage capacity.
3. The method according to claim 2, characterized in that, Based on the engine's operating conditions, calculate the excess oxygen flowing through the catalytic converter before and after engine start-up, including: Based on the engine shutdown time before startup, calculate the first excess oxygen flowing through the catalyst during the shutdown process; Calculate the excess oxygen coefficient and excess fuel coefficient based on the air-fuel ratio after engine start-up; Based on the intake air volume, the excess oxygen coefficient, and the excess fuel coefficient under the non-fuel-cut-off condition after engine start-up, calculate the second excess oxygen quantity and the excess fuel quantity under the non-fuel-cut-off condition. Based on the intake air volume under the fuel cut-off condition after engine start-up, set the excess air coefficient for the fuel cut-off condition. The excess oxygen amount flowing through the catalyst before and after engine start-up is set based on the first excess oxygen amount, the second excess oxygen amount, the excess fuel amount, and the excess air coefficient.
4. The method according to claim 2, characterized in that, After calculating the actual oxygen storage capacity based on the excess oxygen amount and the rate at which the excess oxygen is absorbed by the catalyst, the method further includes: Obtain the voltage value of the post-oxygen sensor connected to the catalyst; If the voltage value is greater than the voltage threshold, the oxygen storage capacity of the catalyst is corrected to a preset value to obtain the corrected oxygen storage capacity of the catalyst. If the voltage value is less than or equal to the voltage threshold, then the actual oxygen storage capacity is set to the corrected catalyst oxygen storage capacity. The value of the actual oxygen storage is updated based on the corrected oxygen storage capacity of the catalyst.
5. The method according to claim 2, characterized in that, The maximum oxygen storage capacity of the catalyst is obtained based on its operating conditions, including: The catalyst temperature is obtained and filtered to obtain the filtered catalyst temperature. The degree of aging of the catalyst is calculated based on the exhaust flow rate entering the catalyst during oscillation control, the detection value of the oxygen sensor before the catalyst, and the detection value of the oxygen sensor after the catalyst. Query the temperature correction value corresponding to the filtered catalyst temperature, and query the aging correction value corresponding to the aging degree; Based on the temperature correction value and the aging correction value, the maximum oxygen storage capacity of the catalyst at the factory is corrected to obtain the maximum oxygen storage capacity of the catalyst.
6. The method according to claim 1, characterized in that, Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, after controlling the engine to delay fuel cut-off or enter fuel cut-off condition, the method further includes: The engine-associated first temperature detection group, the catalyst-associated second temperature detection group, and the engine speed are obtained. If the oxygen storage capacity coefficient is less than the oxygen storage capacity threshold, and each temperature in the first detection temperature group is in the corresponding first temperature range, each temperature in the second detection temperature group is in the corresponding second temperature range, and the engine speed is less than the speed threshold, then query the target angle corresponding to the engine speed. Adjust the valve overlap angle to the target angle.
7. The method according to claim 1, characterized in that, Based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation, the engine is controlled to delay fuel cut-off or enter fuel cut-off mode, including: If the oxygen storage capacity coefficient is greater than the maximum value of the reference capacity coefficient range, and the target air-fuel ratio compensation is less than the air-fuel ratio compensation threshold, then it is detected that the fuel cut-off of the engine needs to be delayed. If the oxygen storage capacity coefficient is less than the minimum value of the reference capacity coefficient range, or the target air-fuel ratio compensation is greater than or equal to the air-fuel ratio compensation threshold, then it is detected that there is no need to delay the fuel cut-off of the engine. If the oxygen storage capacity coefficient is within the range of the reference capacity coefficient, then obtain the set state of whether the fuel cut-off needs to be delayed, and maintain the state. Depending on whether a delayed fuel cut-off is required, the engine can be controlled to either delay fuel cut-off or directly enter the fuel cut-off state.
8. An engine control device, characterized in that, The device includes: The response module is used to respond to the engine fuel cut-off command and calculate the current oxygen storage capacity coefficient of the catalyst based on the actual oxygen storage capacity and the maximum oxygen storage capacity of the catalyst. The query module is used to query the target air-fuel ratio compensation required for oxygen removal from the catalyst according to the oxygen storage capacity coefficient. The fuel cut-off module is used to control the engine to delay fuel cut-off or enter fuel cut-off mode based on the oxygen storage capacity coefficient and the target air-fuel ratio compensation. The fuel injection module is used to query the target air-fuel ratio compensation factor required for oxygen removal from the catalyst based on the oxygen storage capacity coefficient when the oxygen storage capacity coefficient is greater than the capacity coefficient threshold and the engine has started; increase the fuel injection quantity according to the target air-fuel ratio compensation factor; and stop fuel injection and reset the target air-fuel ratio compensation factor when the oxygen storage capacity coefficient is less than the capacity coefficient threshold.
9. A vehicle, characterized in that, include: One or more processors; A storage device for storing one or more programs that, when executed by one or more processors, cause the vehicle to perform the method as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, It stores computer-readable instructions that, when executed by the computer's processor, cause the computer to perform the method of any one of claims 1 to 7.