Vehicle control method and system, vehicle and storage medium

Abstract

The invention provides a vehicle control method and system, a vehicle and a storage medium, and the method comprises the steps that when the temperature of a downstream switch oxygen sensor is smaller than the dew point temperature, an engine control unit determines the target maximum allowable rotating speed and the target maximum allowable torque of an engine according to the water temperature of the engine, a working condition coordination request is sent to the hybrid power control unit; and the hybrid power control unit controls the engine and the motor to enter a series connection mode according to the working condition coordination request, and controls the maximum allowable rotating speed of the engine to be smaller than or equal to the target maximum allowable rotating speed and the maximum allowable torque of the engine to be smaller than or equal to the target maximum allowable torque. Therefore, the actual rotating speed of the engine does not exceed the target maximum allowable rotating speed, and the actual torque of the engine does not exceed the target maximum allowable torque. The temperature of the engine in the combustion process can be reduced, generation of harmful substances in originally discharged waste gas is reduced, and therefore the emission performance of the vehicle is improved to a certain degree.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically to a vehicle control method, system, vehicle, and storage medium. Background Technology

[0002] Hybrid vehicles typically include a three-way catalytic converter to reduce the levels of harmful substances (such as carbon monoxide and nitrogen oxides) in the exhaust gases produced by the engine. To ensure the efficiency of the three-way catalytic converter in converting harmful substances in the exhaust gases, an upstream wide-range oxygen sensor is usually installed between the engine exhaust manifold and the three-way catalytic converter, while a downstream on / off oxygen sensor is installed on the three-way catalytic converter or its tailpipe.

[0003] Currently, the air-fuel ratio correction is typically determined based on the self-learning mode of the downstream switched oxygen sensor. This correction is then used to adjust the excess air coefficient (i.e., the engine's air-fuel ratio) of the upstream wide-range oxygen sensor, thereby reducing the content of harmful substances in the engine's exhaust gases. In practical applications, the downstream switched oxygen sensor typically needs to reach its operating temperature threshold before it can begin functioning.

[0004] However, in some cold-start engine applications, the downstream switched oxygen sensor typically needs time to reach its operating temperature threshold. Therefore, the downstream switched oxygen sensor may fail to activate in time, potentially leading to excessive emissions of harmful substances and reducing the vehicle's emissions performance.

[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] This application provides a vehicle control method, system, vehicle, and storage medium to address the problem in related technologies where the failure of downstream oxygen sensors to operate in a timely manner may result in lower vehicle emission performance.

[0007] In a first aspect, embodiments of this application provide a vehicle control method, including: The engine control unit obtains the temperature of the downstream switch oxygen sensor of the three-way catalytic converter; When the temperature of the downstream oxygen sensor is lower than the dew point temperature, the engine control unit determines the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature, and sends a working condition coordination request to the hybrid power control unit. According to the operating condition coordination request, the hybrid power control unit controls the engine and the electric motor to enter series mode, and controls the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque.

[0008] In one possible implementation, determining the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature includes: Based on the engine coolant temperature and the three-way catalytic converter temperature, determine the engine's target maximum permissible speed and target maximum permissible torque.

[0009] In one possible implementation, controlling the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque, includes: The maximum permissible speed of the engine is controlled to be equal to the target maximum permissible speed, and the maximum permissible torque of the engine is equal to the target maximum permissible torque.

[0010] In one possible implementation, sending the operating condition coordination request to the hybrid power control unit includes: If the engine's operating environment meets the first preset conditions, a working condition coordination request is sent to the hybrid power control unit. The first preset condition includes: the engine coolant temperature is within a preset coolant temperature range, the external ambient temperature is within a preset external ambient temperature range, and the external atmospheric pressure is greater than a preset first external atmospheric pressure threshold.

[0011] In one possible implementation, the method further includes: When the temperature of the downstream oxygen sensor is greater than or equal to the dew point temperature, or the first duration is greater than a preset first duration threshold, or the engine's operating environment meets a second preset condition, the engine control unit sends an exit condition coordination request to the hybrid power control unit. The hybrid power control unit does not respond to the operating condition coordination request based on the exit operating condition coordination request; Wherein, the first duration is the continuous duration for which the engine control unit receives the first response information, and the first response information is the information fed back to the engine control unit when the hybrid power control unit does not respond to the operating condition coordination request; The second preset condition includes: the engine coolant temperature is not within the coolant temperature range, or the external ambient temperature is not within the external ambient temperature range, or the external atmospheric pressure is less than a preset second external pressure threshold, wherein the first external pressure threshold is greater than the second external pressure threshold.

[0012] In one possible implementation, the hybrid power control unit controls the engine and electric motor to enter a series mode according to the operating condition coordination request, including: If the allowable discharge power of the power battery is greater than the power required by the driver and the remaining charge of the power battery is greater than a preset first remaining charge threshold, then the hybrid power control unit controls the engine and the electric motor to enter series mode according to the working condition coordination request.

[0013] In one possible implementation, the method further includes: If the allowed discharge power is less than or equal to a preset allowed discharge power threshold and the second duration is greater than a preset second duration threshold, or the remaining charge is less than a preset second remaining charge threshold, then the hybrid power control unit does not respond to the operating condition coordination request and sends a first response information to the engine control unit. Wherein, the allowable discharge power threshold is greater than the driver's required power, the second duration is the duration during which the allowable discharge power is less than the allowable discharge power threshold, and the first remaining power threshold is greater than the second remaining power threshold.

[0014] In one possible implementation, the method further includes: When the temperature of the downstream switched oxygen sensor is lower than the dew point temperature, the engine control unit heats the downstream switched oxygen sensor using a first heating power. When the temperature of the downstream switched oxygen sensor is greater than or equal to the dew point temperature, the engine control unit heats the downstream switched oxygen sensor using a second heating power. Wherein, the first heating power is less than the second heating power.

[0015] In one possible implementation, the method further includes: When the temperature of the downstream oxygen sensor is greater than or equal to a preset operating temperature threshold, the engine control unit determines the fuel injection quantity of the engine based on the difference between the target air-fuel ratio and the actual air-fuel ratio, so that the air-fuel ratio of the engine matches the optimal conversion efficiency of the three-way catalytic converter. The target air-fuel ratio is the air-fuel ratio corrected by the engine control unit based on the self-learning mode of the downstream oxygen sensor.

[0016] Secondly, embodiments of this application provide a vehicle control system, including: The engine control unit is used to obtain the temperature of the downstream switch oxygen sensor of the three-way catalytic converter. The engine control unit is also used to determine the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature when the temperature of the downstream switch oxygen sensor is lower than the dew point temperature, and to send a working condition coordination request to the hybrid power control unit. The hybrid power control unit is used to control the engine and the electric motor to enter a series mode according to the working condition coordination request, and to control the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque.

[0017] Thirdly, embodiments of this application provide a vehicle, including: the control system described in the second aspect.

[0018] Fourthly, embodiments of this application provide a computer-readable storage medium, comprising: the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method described in any one of the first aspects.

[0019] In this embodiment, when the downstream oxygen sensor temperature has not reached the dew point temperature, the engine and electric motor are controlled to enter a series mode, and the engine's maximum permissible speed and maximum permissible torque are controlled to be less than or equal to the target maximum permissible speed and torque, respectively. This ensures that the engine's actual speed and torque do not exceed the target maximum permissible speed and torque. Because the engine's actual speed and torque are limited before the downstream oxygen sensor temperature reaches the dew point temperature, the engine temperature during combustion is reduced, decreasing the generation of harmful substances in the original exhaust gases, thereby improving the vehicle's emission performance to some extent. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this application.

[0022] Figure 2 This is a flowchart illustrating a vehicle control method provided in an embodiment of this application.

[0023] Figure 3 This is a structural schematic diagram of a vehicle provided in an embodiment of this application.

[0024] Figure 4This is a flowchart illustrating another vehicle control method provided in an embodiment of this application.

[0025] Figure 5 This is a flowchart illustrating another vehicle control method provided in an embodiment of this application.

[0026] Figure 6 This is a flowchart illustrating another vehicle control method provided in an embodiment of this application.

[0027] Figure 7 This is a schematic diagram illustrating the relationship between heating voltage and heating time, provided as an embodiment of this application.

[0028] Figure 8 This is a schematic diagram of the structure of a vehicle control system provided in an embodiment of this application.

[0029] Figure 9 This is a schematic diagram of another vehicle structure provided in an embodiment of this application. Detailed Implementation

[0030] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0031] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0032] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should be understood that the term "and / or" used in this article 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, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0034] See Figure 1 This is a schematic diagram illustrating an application scenario provided by an embodiment of this application. For example... Figure 1 As shown, the vehicle 100 includes an upstream wide-range oxygen sensor 101, a three-way catalytic converter 102, and a downstream on / off oxygen sensor 103. The three-way catalytic converter 102 can convert harmful substances (e.g., carbon monoxide and nitrogen oxides) in the exhaust gas produced by the engine, thereby reducing the content of harmful substances in the exhaust gas.

[0035] Understandably, the upstream wide-range oxygen sensor 101 is typically installed between the engine exhaust manifold and the three-way catalytic converter 102. It typically monitors the oxygen content in the exhaust gas produced by the engine in real time and feeds the corresponding monitoring information back to the engine control unit. The engine control unit adjusts the engine's air-fuel ratio based on this monitoring information to achieve closed-loop control, ensuring the engine reaches its optimal operating state. The downstream on-off oxygen sensor 103 is typically installed on the three-way catalytic converter 102 or its tailpipe. It typically monitors the oxygen content in the exhaust gas after conversion by the three-way catalytic converter 102 and feeds the corresponding monitoring information back to the engine control unit. The engine control unit adjusts the control strategy of the upstream wide-range oxygen sensor 101 based on this monitoring information to ensure the three-way catalytic converter 102 reaches its optimal operating state.

[0036] It should be pointed out that, Figure 1 The vehicle 100 shown is merely an exemplary description and should not be construed as a limitation on the scope of protection of this application.

[0037] Currently, the air-fuel ratio correction amount is usually determined based on the self-learning mode of the downstream switching oxygen sensor, in order to correct the excess air coefficient (i.e., the air-fuel ratio of the engine) of the upstream wide-range oxygen sensor, thereby reducing the content of harmful substances in the engine exhaust gas.

[0038] In practical applications, the downstream oxygen sensor typically needs to reach its operating temperature threshold before it can begin to function. For example, this threshold might be 250 degrees Celsius, 300 degrees Celsius, or 350 degrees Celsius. To ensure the downstream oxygen sensor reaches its operating temperature threshold quickly, it is usually equipped with a resistance wire for heating.

[0039] However, engine exhaust typically contains water vapor, which may be low in temperature before the downstream oxygen sensor reaches its dew point. This can cause water vapor to condense on the sensor, forming condensate. If a high heating power is used to heat the sensor at this point, its temperature may rise rapidly, leading to the condensate evaporating and expanding rapidly, generating significant internal pressure and potentially causing the ceramic housing of the sensor to crack. Therefore, before the downstream oxygen sensor reaches its dew point, it is usually heated with exhaust gas or at a low power. Once the sensor reaches its dew point, a higher heating power is used to quickly bring it to its operating temperature threshold, allowing it to begin operation.

[0040] However, in some cold-start engine applications, the downstream switched oxygen sensor typically requires a certain amount of time to reach its operating temperature threshold. Therefore, the downstream switched oxygen sensor may fail to activate in a timely manner. The lack of feedback from the downstream switched oxygen sensor can lead to excessive emissions of harmful substances, thereby reducing the vehicle's emissions performance.

[0041] For example, when a hybrid vehicle starts its engine cold under high-speed conditions due to power demand or remaining battery charge, the engine load is high, producing more exhaust gas and the exhaust gas recirculation system is shut off. At this time, the downstream oxygen sensor may not have reached its dew point temperature, potentially preventing it from quickly reaching its operating temperature threshold and correcting the engine's air-fuel ratio. Without the downstream oxygen sensor's self-learning mode to correct the air-fuel ratio, it may become too low or too high, resulting in incomplete combustion of the air-fuel mixture (fuel and air). This can lead to excessive emissions of harmful substances and reduced vehicle emissions performance.

[0042] To address the aforementioned issues, in this embodiment, when the downstream oxygen sensor temperature has not reached the dew point temperature, the engine and electric motor are controlled to enter a series mode, and the engine's maximum permissible speed and maximum permissible torque are controlled to be less than or equal to the target maximum permissible speed and torque, respectively. This ensures that the engine's actual speed and torque do not exceed the target maximum permissible speed and torque. Because the engine's actual speed and torque are limited before the downstream oxygen sensor temperature reaches the dew point temperature, the engine's temperature during combustion is reduced, decreasing the generation of harmful substances in the original exhaust gases, thereby improving the vehicle's emission performance to some extent.

[0043] Specifically, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0044] See Figure 2 This is a flowchart illustrating a vehicle control method provided in an embodiment of this application. This method can be applied to... Figure 1 In the application scenarios shown, such as Figure 1 As shown, it mainly includes the following steps.

[0045] Step S201: The engine control unit obtains the temperature of the downstream switch oxygen sensor of the three-way catalytic converter.

[0046] In practical applications, hybrid vehicles may be equipped with multiple downstream on-off oxygen sensor temperatures. As mentioned above, when the temperature of the downstream on-off oxygen sensor of the three-way catalytic converter has not reached the dew point temperature, the emission performance of the hybrid vehicle may be low. Therefore, it is necessary to first obtain the temperature of the downstream on-off oxygen sensor of the three-way catalytic converter to determine whether the downstream on-off oxygen sensor temperature has reached the dew point temperature.

[0047] See Figure 3 This is a structural schematic diagram of a vehicle provided in an embodiment of this application. Figure 3 As shown, vehicle 300 includes engine control unit 301, hybrid power control unit 302, sensor management unit 303, and battery management unit 304. Engine control unit 301 is communicatively connected to hybrid power control unit 302 and sensor management unit 303, and hybrid power control unit 302 is also communicatively connected to battery management unit 304, thereby enabling information exchange.

[0048] Among them, the sensor management unit 303 can monitor information such as the temperature of the downstream switch oxygen sensor, the external ambient temperature and the external atmospheric pressure, and can send it to the engine control unit 301; the battery management unit 304 can monitor information such as the remaining charge and allowable discharge power of the power battery, and can send it to the hybrid power control unit 302.

[0049] In this embodiment, the engine control unit 301 and the hybrid power control unit 302 control the engine's operating state based on relevant information sent by the sensor management unit 303 and the battery management unit 304, so as to improve the vehicle's emission performance.

[0050] Step S202: When the downstream switch oxygen sensor temperature is lower than the dew point temperature, the engine control unit determines the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature, and sends a working condition coordination request to the hybrid power control unit.

[0051] As mentioned above, the downstream oxygen sensor cannot function when its temperature is below the dew point temperature. Therefore, to reduce harmful emissions, it is necessary to limit the engine's maximum permissible speed and maximum permissible torque, thereby limiting the engine's actual speed and actual torque.

[0052] In this embodiment, engine coolant temperature is closely related to engine emissions performance. Generally, when the engine coolant temperature is within a certain range, fuel combustion is more complete, resulting in relatively better emissions performance. Therefore, the target maximum permissible speed and target maximum permissible torque of the engine can be determined by the engine coolant temperature.

[0053] In practice, the ability of a three-way catalytic converter to convert harmful substances is limited. When the engine emits excessive exhaust gases, the conversion efficiency of the three-way catalytic converter is relatively low, which may result in lower emission performance in hybrid vehicles.

[0054] In one possible implementation, the target maximum permissible engine speed and target maximum permissible torque are determined based on the engine coolant temperature and the three-way catalytic converter temperature. It is understood that when the three-way catalytic converter temperature is within a certain range, its conversion efficiency is better, enabling it to convert more harmful substances, thereby improving the emission performance of hybrid vehicles.

[0055] In practice, based on the engine coolant temperature and the three-way catalytic converter temperature, the target maximum permissible speed corresponding to these temperatures is determined in the first mapping table. This first mapping table can be understood as a table showing the correspondence between the target maximum permissible speed and the engine coolant temperature and the three-way catalytic converter temperature.

[0056] In this embodiment, after determining the target maximum permissible speed, the target maximum permissible torque corresponding to the engine coolant temperature and the target maximum permissible speed is determined in a second mapping table based on the engine coolant temperature and the target maximum permissible speed. The second mapping table is a table showing the correspondence between the target maximum permissible torque and the engine coolant temperature and the target maximum permissible speed.

[0057] It is understandable that each engine speed typically corresponds to an external characteristic torque, which is the maximum torque the engine can output at that speed. Therefore, it is necessary to determine the target maximum permissible torque based on the target maximum permissible speed.

[0058] In this embodiment, the target maximum permissible speed and target maximum permissible torque of the engine are determined by the engine coolant temperature and the three-way catalytic converter temperature. This ensures that the hybrid vehicle operates under good conditions in terms of engine emission performance and three-way catalytic converter conversion efficiency, thereby improving the emission performance of the hybrid vehicle to a certain extent.

[0059] In practical applications, when the downstream oxygen sensor temperature is lower than the dew point temperature, the downstream oxygen sensor cannot operate in a timely manner. Without feedback from the downstream oxygen sensor, the emission control robustness of hybrid vehicles may be low. Therefore, the engine control unit needs to send a condition coordination request to the hybrid control unit to instruct the hybrid control unit to limit the engine's maximum permissible speed and maximum permissible torque, thereby reducing the engine's raw emissions and improving the emission control robustness of the hybrid vehicle.

[0060] However, in some application scenarios, the engine's external characteristics, such as output power or fuel consumption rate, may degrade. For example, when a hybrid vehicle is driven at high altitudes, the lower external atmospheric pressure may reduce the engine's intake air volume, causing a degradation in the engine's external characteristics. In this case, if the engine's maximum permissible speed and maximum permissible torque are still limited, the engine's external characteristics may degrade excessively, potentially leading to insufficient power output from the hybrid vehicle and affecting the driving experience.

[0061] In other application scenarios, characteristics such as the total amount of electrical energy that a power battery can store and release (i.e., power battery capacity) may degrade. For example, when a hybrid vehicle is driven in high-temperature or low-temperature regions, the slower migration rate of lithium ions inside the power battery may lead to a decrease in conductivity and a reduction in battery capacity. In this case, if the maximum permissible engine speed and maximum permissible torque are still limited, the characteristics of the power battery may degrade excessively, potentially resulting in insufficient power output from the hybrid vehicle and affecting the driving experience.

[0062] See Figure 4 This is a flowchart illustrating another vehicle control method provided in an embodiment of this application. The embodiments of this application... Figure 2 Based on the illustrated embodiment, step S202 includes step S401.

[0063] Step S401: When the downstream oxygen sensor temperature is lower than the dew point temperature, the engine control unit determines the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature. If the engine's operating environment meets the first preset condition, a working condition coordination request is sent to the hybrid power control unit.

[0064] In this embodiment, the engine's operating environment includes, but is not limited to, engine coolant temperature, ambient temperature, and atmospheric pressure. The first preset conditions include: the engine coolant temperature is within a preset coolant temperature range, the ambient temperature is within a preset ambient temperature range, and the atmospheric pressure is greater than a preset first atmospheric pressure threshold. Each of the first preset conditions will be described in detail below.

[0065] Condition 1 of the first preset condition: The engine coolant temperature is within a preset coolant temperature range. This range can be represented as [entry coolant temperature threshold, exit coolant temperature threshold]. It can be understood that the entry coolant temperature threshold is less than the exit coolant temperature threshold. When the engine coolant temperature is greater than the entry coolant temperature threshold but less than the exit coolant temperature threshold, the engine's external characteristics may not be degraded. In this case, to reduce the engine's raw emissions, the engine control unit can send a condition coordination request to the hybrid power control unit to instruct it to limit the engine's maximum permissible speed and maximum permissible torque.

[0066] For example, the water temperature range is [entry water temperature threshold A, exit water temperature threshold A]. When the entry engine water temperature A ≤ engine water temperature A ≤ exit water temperature threshold A, the engine's external characteristics may not be attenuated, and the engine control unit can send a condition coordination request to the hybrid control unit.

[0067] Condition 2 of the first preset condition: The external ambient temperature is within a preset external ambient temperature range. This range can be represented as [entry external ambient temperature, exit external ambient temperature]. It can be understood that the entry external ambient temperature is lower than the exit external ambient temperature. When the external ambient temperature is higher than the entry external ambient temperature but lower than the exit external ambient temperature, it can be assumed that the hybrid vehicle is not operating in a high-temperature or low-temperature region, and the external characteristics of the engine and the power battery may not have been degraded. In this case, to reduce the engine's raw emissions, the engine control unit can send a condition coordination request to the hybrid control unit to instruct it to limit the engine's maximum permissible speed and maximum permissible torque.

[0068] For example, the external ambient temperature range is [entry external ambient temperature A, exit external ambient temperature A]. When the entry external ambient temperature A ≤ external ambient temperature A ≤ exit external ambient temperature A, the external characteristics of the engine and the characteristics of the power battery may not be degraded, and the engine control unit can send a condition coordination request to the hybrid power control unit.

[0069] Condition 3 in the first preset condition: The external atmospheric pressure is greater than the preset first external atmospheric pressure threshold. It can be understood that when the external atmospheric pressure is greater than the first external atmospheric pressure threshold, it can be assumed that the hybrid vehicle is driving in a flat area, and the engine's external characteristics may not be diminished. In this case, in order to reduce the engine's raw emissions, the engine control unit can send a condition coordination request to the hybrid control unit to instruct it to limit the engine's maximum permissible speed and maximum permissible torque.

[0070] It should be noted that the entry water temperature threshold, exit water temperature threshold, entry external ambient temperature threshold, exit external ambient temperature threshold, and first external atmospheric pressure threshold are preset values. Those skilled in the art can set the corresponding thresholds according to actual needs, and the embodiments of this application do not impose specific limitations on this.

[0071] In this embodiment, when the downstream oxygen sensor temperature is lower than the dew point temperature, if the hybrid vehicle is not driven in high-altitude, high-temperature, or low-temperature areas, the maximum permissible speed and maximum permissible torque of the engine can be limited. While ensuring the power output and power retention performance of the hybrid vehicle, the original emissions of the engine are reduced to a certain extent, thus improving the emission performance of the hybrid vehicle.

[0072] See Figure 5 This is a flowchart illustrating another vehicle control method provided in an embodiment of this application. The embodiments of this application... Figure 4 Based on the illustrated embodiment, step S501 is also included.

[0073] Step S501: When the downstream switch oxygen sensor temperature is greater than or equal to the dew point temperature, or the first duration is greater than the preset first duration threshold, or the engine's operating environment meets the second preset condition, the engine control unit sends an exit condition coordination request to the hybrid power control unit.

[0074] Understandably, once the downstream oxygen sensor temperature is greater than or equal to the dew point temperature, it can quickly reach its operating temperature threshold and begin operation. Because the downstream oxygen sensor's self-learning mode can correct the engine's air-fuel ratio and improve the emissions performance of hybrid vehicles, when the downstream oxygen sensor temperature is greater than or equal to the dew point temperature, a disengagement request needs to be sent to the hybrid power control unit to instruct the unit not to limit the engine's maximum permissible speed and maximum permissible torque.

[0075] In this embodiment, when the hybrid power control unit does not respond to the operating condition coordination request, it sends a first response message to the engine control unit; when the hybrid power control unit responds to the operating condition coordination request, it sends a second response message to the engine control unit.

[0076] It is understood that the first response information is the information fed back to the engine control unit when the hybrid power control unit does not respond to the operating condition coordination request, and the second response information is the information fed back to the engine control unit when the hybrid power control unit responds to the operating condition coordination request.

[0077] Therefore, when the duration for which the engine control unit receives the first response information (i.e., the first duration) exceeds the first duration threshold, it can be assumed that the hybrid power control unit may have failed to respond to the operating condition coordination request for an extended period due to factors such as power demand or power reserve requirements. In this case, the engine control unit needs to send an exit from operating condition coordination request to the hybrid power control unit to indicate that the hybrid power control unit does not need to limit the engine's maximum permissible speed and maximum permissible torque.

[0078] It should be noted that the first duration threshold is a preset value, which can be 10s, 15s, etc. In practical applications, those skilled in the art can set other first duration thresholds, and this application embodiment does not impose specific limitations on this.

[0079] In this embodiment, the second preset condition includes: the engine coolant temperature is not within a preset coolant temperature range, or the external ambient temperature is not within a preset external ambient temperature range, or the external atmospheric pressure is less than a preset second external atmospheric pressure threshold. Each of the second preset conditions will be described in detail below.

[0080] Condition 1 of the second preset condition: Engine coolant temperature is not within the coolant temperature range. This means that when the engine coolant temperature is below the entry temperature threshold or above the exit temperature threshold, the engine temperature can be considered high or low, and the engine's external characteristics are diminished. In this case, to ensure the power output of the hybrid vehicle, the engine control unit needs to send an exit condition coordination request to the hybrid control unit, instructing the hybrid control unit not to limit the engine's maximum permissible speed and maximum permissible torque.

[0081] For example, the water temperature range is [entry water temperature threshold A, exit water temperature threshold A]. When the engine water temperature B < entry water temperature threshold A or the engine water temperature B > exit water temperature threshold A, the engine's external characteristics are degraded, and the engine control unit sends an exit condition coordination request to the hybrid power control unit.

[0082] However, when the engine coolant temperature fluctuates near the entry or exit temperature threshold, the control of the engine's maximum permissible speed and maximum permissible torque frequently switches between limiting and unlimiting strategies, which may cause large fluctuations in the power output of hybrid vehicles and affect the driving experience.

[0083] Therefore, in one possible implementation, when the engine coolant temperature is lower than a first coolant temperature threshold or higher than a second coolant temperature threshold, the engine control unit sends an exit condition coordination request to the hybrid power control unit.

[0084] The first water temperature threshold is lower than the entry water temperature threshold; the second water temperature threshold is higher than the exit water temperature threshold. It can be understood that when the engine water temperature is lower than the entry water temperature threshold or higher than the exit water temperature threshold, although the engine's external characteristics may be attenuated, in order to ensure a smoother power output for the hybrid vehicle, the engine control unit does not immediately send an exit condition coordination request to the hybrid control unit.

[0085] In this embodiment, the engine control unit sends an exit condition coordination request to the hybrid control unit only when the engine coolant temperature is lower than the first coolant temperature threshold or higher than the second coolant temperature threshold. This avoids the problem of large fluctuations in the power output of the hybrid vehicle that may be caused by the engine coolant temperature fluctuating near the entry or exit coolant temperature threshold, and improves the driving experience to a certain extent.

[0086] It should be noted that the first and second water temperature thresholds are preset values. In practical applications, those skilled in the art can set other first and second water temperature thresholds, and this application embodiment does not impose specific limitations on this.

[0087] Condition 2 of the second preset condition: The external ambient temperature is not within the specified range. This means that when the external ambient temperature is lower than the entry temperature but higher than the exit temperature, the hybrid vehicle can be considered to be operating in a high-temperature or low-temperature region, resulting in a degradation of the engine's external characteristics and the battery's performance. In this case, to ensure the hybrid vehicle's power output and the battery's charge retention performance, the engine control unit needs to send an exit condition coordination request to the hybrid control unit, instructing it not to limit the engine's maximum permissible speed and maximum permissible torque.

[0088] For example, the external ambient temperature range is [entering external ambient temperature A, exiting external ambient temperature A]. When the external ambient temperature B < entering external ambient temperature A or external ambient temperature B > exiting external ambient temperature A, the external characteristics of the engine and the characteristics of the power battery are degraded, and the engine control unit sends an exit condition coordination request to the hybrid power control unit.

[0089] However, when the ambient temperature fluctuates around or away from the ambient temperature, the control of the engine's maximum permissible speed and maximum permissible torque frequently switches between limiting and unlimiting strategies, which may cause large fluctuations in the power output of hybrid vehicles and affect the driving experience.

[0090] Therefore, in one possible implementation, when the external ambient temperature is less than a preset first external ambient temperature threshold or greater than a preset second external ambient temperature threshold, the engine control unit sends an exit condition coordination request to the hybrid power control unit.

[0091] Specifically, the first external ambient temperature threshold is lower than the entry external ambient temperature threshold; the second external ambient temperature threshold is also lower than the entry external ambient temperature threshold. It can be understood that when the external ambient temperature is lower than the entry external ambient temperature but higher than the exit external ambient temperature, although the external characteristics of the engine and the characteristics of the power battery may be degraded, in order to ensure a smoother power output for the hybrid vehicle, the engine control unit does not immediately send an exit condition coordination request to the hybrid power control unit.

[0092] In this embodiment, the engine control unit sends an exit condition coordination request to the hybrid control unit only when the external ambient temperature is lower than the first external ambient temperature threshold or higher than the second external ambient temperature threshold. This avoids the problem of large fluctuations in the power output of the hybrid vehicle that may be caused by fluctuations in the external ambient temperature or the exit external ambient temperature, and improves the driving experience to a certain extent.

[0093] It should be noted that the first and second external ambient temperature thresholds are preset values. In practical applications, those skilled in the art can set other first and second external ambient temperature thresholds, and this application embodiment does not impose specific limitations on this.

[0094] Condition 3 of the second preset condition: The external atmospheric pressure is less than the preset second external atmospheric pressure threshold. The first external pressure threshold is greater than the second external atmospheric pressure threshold. It can be understood that when the external atmospheric pressure is greater than the first external atmospheric pressure threshold, it can be considered that the hybrid vehicle is operating at high altitudes, and the engine's external characteristics may be degraded. In this case, to ensure the power output of the hybrid vehicle and the battery's charge retention performance, the engine control unit needs to send an exit condition coordination request to the hybrid control unit to instruct it not to limit the engine's maximum permissible speed and maximum permissible torque.

[0095] However, when the external atmospheric pressure fluctuates around the first external atmospheric pressure threshold, the control of the engine's maximum permissible speed and maximum permissible torque frequently switches between a limiting strategy and an unlimited strategy, which may cause large fluctuations in the power output of hybrid vehicles and affect the driving experience.

[0096] In this embodiment, the engine control unit sends an exit condition coordination request to the hybrid control unit only when the external atmospheric pressure is lower than a second external atmospheric pressure threshold. This avoids the problem of large fluctuations in the power output of the hybrid vehicle that may result from fluctuations in external atmospheric pressure near the external atmospheric pressure threshold, thus improving the driving experience to some extent.

[0097] Step S502: The hybrid power control unit does not respond to the operating condition coordination request based on the exit operating condition coordination request.

[0098] In this embodiment of the application, when the hybrid power control unit receives the exit condition coordination request sent by the engine control unit, the hybrid power control unit needs to respond to the exit condition coordination request and does not limit the maximum permissible speed and maximum permissible torque of the engine.

[0099] For details regarding the specific content involved in the implementation of this application, please refer to the description in the embodiment shown in step S401 above. For the sake of brevity, these details will not be repeated here.

[0100] Step S203: The hybrid power control unit controls the engine and electric motor to enter series mode according to the working condition coordination request, and controls the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque.

[0101] In practical applications, when the engine and electric motor in a hybrid vehicle are in parallel operation, the engine can drive the vehicle's wheels. Because the wheels and engine are connected, the engine's speed and torque are affected by the vehicle speed, making it difficult to control the engine's maximum permissible speed and torque.

[0102] Therefore, in this embodiment, when the hybrid power control unit receives a working condition coordination request from the engine control unit, it prohibits the engine and electric motor from entering parallel mode. In other words, it controls the engine and electric motor to enter series mode.

[0103] Understandably, in series mode, the engine does not directly drive the hybrid vehicle; instead, it charges the battery via a generator. The battery then powers the electric motor, which in turn drives the vehicle. Because the engine's speed and torque are affected by vehicle speed in series mode, it is easier to control the engine's maximum permissible speed and torque.

[0104] In practical applications, if the maximum permissible speed of the engine is less than the target maximum permissible speed, or the maximum permissible torque of the engine is less than the target maximum permissible torque, the hybrid vehicle may not be able to reach the speed between the target maximum permissible speed and the set maximum permissible speed, or the hybrid vehicle may not be able to output the torque between the target maximum permissible torque and the set maximum permissible torque, thus affecting the driving experience.

[0105] In one possible implementation, the hybrid power control unit controls the engine and electric motor to enter series mode according to the operating condition coordination request, and controls the maximum permissible speed of the engine to be equal to the target maximum permissible speed and the maximum permissible torque of the engine to be equal to the target maximum permissible torque.

[0106] In this embodiment, when the engine and electric motor enter series mode, the maximum permissible speed of the engine is controlled to be equal to the target maximum permissible speed, and the maximum permissible torque of the engine is controlled to be equal to the target maximum permissible torque. This enables the hybrid vehicle to achieve a speed between the target maximum permissible speed and the set maximum permissible speed, and allows the hybrid vehicle to output a torque between the target maximum permissible torque and the set maximum permissible torque. This reduces the engine's original emissions, improves the emission performance of the hybrid vehicle, and enhances the driving experience.

[0107] In practical applications, when the allowable discharge power of the power battery cannot meet the driver's demand for high power or when the remaining power of the power battery is insufficient, if the hybrid power control unit immediately responds to the working condition coordination request, prohibits the engine from driving the hybrid vehicle and limits the engine's maximum allowable speed and maximum allowable torque, the hybrid vehicle may lack power and fail to meet the driver's needs, resulting in a poor driving experience.

[0108] See Figure 6 This is a flowchart illustrating another vehicle control method provided in an embodiment of this application. The embodiments of this application... Figure 2 Based on the illustrated embodiment, step S203 includes step S601.

[0109] Step S601: If the allowable discharge power of the power battery is greater than the power required by the driver and the remaining charge of the power battery is greater than the preset first remaining charge threshold, the hybrid power control unit controls the engine and the electric motor to enter series mode according to the working condition coordination request, and controls the maximum allowable speed of the engine to be less than or equal to the target maximum allowable speed and the maximum allowable torque of the engine to be less than or equal to the target maximum allowable torque.

[0110] Understandably, when the allowable discharge power of the power battery exceeds the driver's power demand, the allowable discharge power of the power battery can meet the driver's power demand. When the remaining charge of the power battery exceeds the first remaining charge threshold, the remaining charge of the power battery is sufficient. At this time, in order to improve the emission performance of the hybrid vehicle, the hybrid control unit can respond to the operating condition coordination request to limit the actual speed and actual torque of the engine.

[0111] It should be noted that the first remaining battery power threshold is a preset value. Those skilled in the art can set the first remaining battery power threshold according to actual needs, and the embodiments of this application do not impose specific limitations on this.

[0112] In this embodiment, when the permissible discharge power of the power battery can meet the driver's power requirements and the remaining charge of the power battery is sufficient, the engine and electric motor can be restricted from entering series mode, and the actual speed of the engine can be controlled to not exceed the target maximum permissible speed, and the actual torque of the engine can not exceed the target maximum permissible torque. This reduces the engine's original emissions, improves the emission performance of the hybrid vehicle, and enhances the driving experience.

[0113] In one possible implementation, if the allowed discharge power is less than a preset allowed discharge power threshold and the second duration is greater than a preset second duration threshold or the remaining charge is less than a preset second remaining charge threshold, the hybrid power control unit does not respond to the operating condition coordination request and sends the first response information to the engine control unit.

[0114] The permissible discharge power threshold is greater than the driver's required power. Understandably, when the permissible discharge power is less than the driver's required power, the permissible discharge power cannot meet the driver's power needs. At this point, the hybrid control unit will activate the engine to enter parallel mode, which may cause a momentary decrease in the hybrid vehicle's power output, affecting the driving experience.

[0115] Therefore, in this application, when the allowable discharge power is less than the allowable discharge power threshold, although the allowable discharge power can meet the driver's power requirements, the engine is put into parallel mode in advance, thereby avoiding the problem of instantaneous power shortage that may be caused by the allowable discharge power of the power battery not meeting the driver's power requirements. This improves the driving experience to a certain extent.

[0116] In addition, the duration during which the allowable discharge power of the power battery is less than the allowable discharge power threshold may be relatively short, which may cause the control of the maximum allowable speed and maximum allowable torque of the engine to fluctuate between a restricted strategy and an unrestricted strategy. This may result in large fluctuations in the power output of hybrid vehicles, affecting the driving experience.

[0117] Therefore, in this embodiment, when the allowable discharge power is less than the allowable discharge power threshold and the second duration is greater than the second duration threshold, the hybrid power control unit does not respond to the operating condition coordination request. This avoids the problem of instantaneous power shortage that might occur if the duration of the allowable discharge power of the power battery being less than the allowable discharge power threshold is relatively short. This improves the user experience to some extent.

[0118] The second duration is the duration during which the allowable discharge power of the power battery is less than the allowable discharge power threshold. It should be noted that the allowable discharge power threshold is a preset value. Those skilled in the art can set their own allowable discharge power threshold according to actual needs; this application does not impose specific limitations on this.

[0119] In practical applications, when the remaining charge of the power battery fluctuates around the initial remaining charge level, the control of the engine's maximum permissible speed and maximum permissible torque frequently switches between a limiting strategy and an unlimited strategy, which may cause large fluctuations in the power output of hybrid vehicles and affect the driving experience.

[0120] Therefore, in this embodiment, the hybrid power control unit only stops responding to the operating condition coordination request when the remaining battery charge is less than the second remaining battery charge threshold. This avoids the problem of large fluctuations in the power output of the hybrid vehicle caused by fluctuations in the remaining battery charge around the first remaining battery charge threshold, thus improving the driving experience to some extent.

[0121] It should be noted that the second remaining power threshold is a preset value. Those skilled in the art can set other second remaining power thresholds according to actual needs, and the embodiments of this application do not impose specific limitations on this.

[0122] In this embodiment of the application, when the hybrid power control unit determines that it will not respond to the operating condition coordination request sent by the engine control unit, it needs to send a first response message to the engine control unit to inform the engine control unit that the operating condition coordination request has not been responded to.

[0123] In addition, when the hybrid power control unit determines that it is responding to the operating condition coordination request sent by the engine control unit, it needs to send a second response message to the engine control unit to inform the engine control unit that the operating condition coordination request has been responded to.

[0124] In this embodiment, the information synchronization between the engine control unit and the hybrid control unit is achieved by feeding back the response information of the operating condition coordination request to the engine control unit through the hybrid power control unit.

[0125] As mentioned above, heating the downstream oxygen sensor with a large heating power before the downstream oxygen sensor temperature reaches the dew point temperature may cause the ceramic body of the downstream oxygen sensor to crack, thereby increasing the operating cost of hybrid vehicles.

[0126] In one possible implementation, when the downstream switched oxygen sensor temperature is lower than the dew point temperature, the engine control unit heats the downstream switched oxygen sensor using a first heating power; when the downstream switched oxygen sensor temperature is greater than or equal to the dew point temperature, the engine control unit heats the downstream switched oxygen sensor using a second heating power. The first heating power is less than the second heating power.

[0127] See Figure 7 This is a schematic diagram illustrating the relationship between heating voltage and heating time, provided in an embodiment of this application. Figure 7 As shown, t1 is the moment when the downstream oxygen sensor temperature equals the dew point temperature. When the heating time is less than t1, the downstream oxygen sensor temperature is less than the dew point temperature. At this time, a constant first heating power U1 is used to heat the downstream oxygen sensor, which is the low-power heating stage. When the heating time is greater than or equal to t1, the downstream oxygen sensor temperature is greater than or equal to the dew point temperature. At this time, a constant second heating power U2 is used to heat the downstream oxygen sensor, which is the high-power heating stage.

[0128] Additionally, t2 represents the moment when the downstream switched oxygen sensor temperature reaches its operating temperature threshold. When the heating duration is greater than or equal to t2, the downstream switched oxygen sensor temperature is greater than or equal to the operating temperature threshold. At this time, based on the engine's operating state or exhaust temperature, a corresponding heating voltage is used to heat the downstream switched oxygen sensor, i.e., the MAP heating stage. In this embodiment, the engine control unit typically performs an integral calculation on the heat used to heat the downstream switched oxygen sensor to determine the total heating heat, thereby determining whether the downstream switched oxygen sensor temperature has reached the dew point temperature. The downstream switched oxygen sensor is then heated using a heating voltage corresponding to the total heating heat.

[0129] Specifically, when the total heating heat is less than the heat integration threshold, the first heating power is used to heat the downstream switched oxygen sensor; when the total heating heat is greater than or equal to the heat integration threshold, the second heating power is used to heat the downstream switched oxygen sensor.

[0130] Understandably, when the total heating heat is less than the heat integration threshold, the downstream switched oxygen sensor temperature is lower than the dew point temperature. Therefore, a smaller heating power is used to heat the downstream switched oxygen sensor. When the total heating heat is greater than or equal to the heat integration threshold, the downstream switched oxygen sensor temperature is greater than or equal to the dew point temperature. Therefore, a larger heating power is used to heat the downstream switched oxygen sensor.

[0131] It should be noted that the calorie integration threshold is a preset value. Those skilled in the art can set other calorie integration thresholds according to actual needs, and the embodiments of this application do not impose specific limitations on this.

[0132] In this embodiment, a smaller heating power is used to heat the downstream oxygen sensor before it reaches the dew point temperature. After the downstream oxygen sensor reaches the dew point temperature, a larger heating power is used. This helps to prevent the ceramic body of the downstream oxygen sensor from cracking, thereby reducing the operating cost of the hybrid vehicle.

[0133] In this embodiment, when the temperature of the downstream oxygen sensor is greater than or equal to the operating temperature threshold, the engine control unit determines the amount of fuel injected by the engine based on the difference between the target air-fuel ratio and the actual air-fuel ratio, so that the air-fuel ratio of the engine matches the optimal conversion efficiency of the three-way catalytic converter.

[0134] The target air-fuel ratio is the air-fuel ratio corrected by the engine control unit based on the self-learning mode of the downstream on / off oxygen sensor. Specifically, the target air-fuel ratio = downstream on / off oxygen sensor learned value + upstream wide-range oxygen sensor measured value + air-fuel ratio correction value.

[0135] It is understandable that the downstream switched oxygen sensor learning value is the correction amount for the actual air-fuel ratio determined by the self-learning mode of the downstream switched oxygen sensor. The upstream wide-range oxygen sensor measured value is the air-fuel ratio value of the engine exhaust manifold determined by the upstream wide-range oxygen sensor. The air-fuel ratio correction value is the correction amount for the air-fuel ratio determined by the engine control unit through other methods.

[0136] Furthermore, the actual air-fuel ratio is the air-fuel ratio value of the engine cylinder determined by the engine control unit. In the embodiments of this application, when the downstream switch oxygen sensor is operational, the engine control unit corrects the engine's air-fuel ratio through PID control based on the difference between the target air-fuel ratio and the actual air-fuel ratio, thereby matching the engine's air-fuel ratio with the optimal conversion efficiency of the three-way catalytic converter.

[0137] In this embodiment, when the downstream oxygen sensor temperature has not reached the dew point temperature, the engine and electric motor are controlled to enter a series mode, and the engine's maximum permissible speed and maximum permissible torque are controlled to be less than or equal to the target maximum permissible speed and torque, respectively. This ensures that the engine's actual speed and torque do not exceed the target maximum permissible speed and torque. Because the engine's actual speed and torque are limited before the downstream oxygen sensor temperature reaches the dew point temperature, the engine temperature during combustion is reduced, decreasing the generation of harmful substances in the original exhaust gases, thereby improving the vehicle's emission performance to some extent.

[0138] Corresponding to the above method embodiments, this application also provides a vehicle control system.

[0139] See Figure 8 This is a schematic diagram of the structure of a vehicle control system provided in an embodiment of this application. Figure 8 As shown, the vehicle control system 800 includes an engine control unit 801 and a hybrid power control unit 802. The engine control unit 801 is used to acquire the temperature of the downstream switched oxygen sensor of the three-way catalytic converter; the engine control unit 801 is also used to determine the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature when the downstream switched oxygen sensor temperature is lower than the dew point temperature, and send a working condition coordination request to the hybrid power control unit; the hybrid power control unit 802 is used to control the engine and electric motor to enter a series mode according to the working condition coordination request, and to control the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque.

[0140] For details regarding the specific content involved in the embodiments of this application, please refer to the description of the above method embodiments. For the sake of brevity, these details will not be repeated here.

[0141] Corresponding to the above method embodiments, this application also provides a structural schematic diagram of a vehicle.

[0142] See Figure 9 This is a schematic diagram of another vehicle structure provided in an embodiment of this application. Figure 9 As shown, vehicle 900 includes vehicle control system 800.

[0143] For details regarding the specific content involved in the embodiments of this application, please refer to the description of the above method embodiments. For the sake of brevity, these details will not be repeated here.

[0144] Corresponding to the above embodiments, this application also provides a computer-readable storage medium, wherein the computer-readable storage medium may store a program, wherein when the program runs, it can control the device where the computer-readable storage medium is located to execute some or all of the steps in the above method embodiments. In specific implementation, the computer-readable storage medium may be a magnetic disk, an optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0145] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0146] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0147] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0148] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0149] The above description is merely a specific embodiment of this application. 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 protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for controlling a vehicle, characterized in that, include: The engine control unit obtains the temperature of the downstream switch oxygen sensor of the three-way catalytic converter; When the temperature of the downstream oxygen sensor is lower than the dew point temperature, the engine control unit determines the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature, and sends a working condition coordination request to the hybrid power control unit. According to the operating condition coordination request, the hybrid power control unit controls the engine and the electric motor to enter series mode, and controls the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque.

2. The method according to claim 1, characterized in that, The process of determining the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature includes: Based on the engine coolant temperature and the three-way catalytic converter temperature, determine the engine's target maximum permissible speed and target maximum permissible torque.

3. The method according to claim 1, characterized in that, The control of the engine's maximum permissible speed being less than or equal to the target maximum permissible speed, and the engine's maximum permissible torque being less than or equal to the target maximum permissible torque, includes: The maximum permissible speed of the engine is controlled to be equal to the target maximum permissible speed, and the maximum permissible torque of the engine is equal to the target maximum permissible torque.

4. The method according to claim 1, characterized in that, Sending the operating condition coordination request to the hybrid power control unit includes: If the engine's operating environment meets the first preset conditions, a working condition coordination request is sent to the hybrid power control unit. The first preset condition includes: the engine coolant temperature is within a preset coolant temperature range, the external ambient temperature is within a preset external ambient temperature range, and the external atmospheric pressure is greater than a preset first external atmospheric pressure threshold.

5. The method according to claim 4, characterized in that, The method further includes: When the temperature of the downstream oxygen sensor is greater than or equal to the dew point temperature, or the first duration is greater than a preset first duration threshold, or the engine's operating environment meets a second preset condition, the engine control unit sends an exit condition coordination request to the hybrid power control unit. The hybrid power control unit does not respond to the operating condition coordination request based on the exit operating condition coordination request; Wherein, the first duration is the continuous duration for which the engine control unit receives the first response information, and the first response information is the information fed back to the engine control unit when the hybrid power control unit does not respond to the operating condition coordination request; The second preset condition includes: the engine coolant temperature is not within the coolant temperature range, or the external ambient temperature is not within the external ambient temperature range, or the external atmospheric pressure is less than a preset second external pressure threshold, wherein the first external pressure threshold is greater than the second external pressure threshold.

6. The method according to claim 1, characterized in that, The hybrid power control unit, based on the operating condition coordination request, controls the engine and electric motor to enter series mode, including: If the allowable discharge power of the power battery is greater than the power required by the driver and the remaining charge of the power battery is greater than a preset first remaining charge threshold, then the hybrid power control unit controls the engine and the electric motor to enter series mode according to the working condition coordination request.

7. The method according to claim 6, characterized in that, The method further includes: If the allowed discharge power is less than or equal to a preset allowed discharge power threshold and the second duration is greater than a preset second duration threshold, or the remaining charge is less than a preset second remaining charge threshold, then the hybrid power control unit does not respond to the operating condition coordination request and sends a first response information to the engine control unit. Wherein, the allowable discharge power threshold is greater than the driver's required power, the second duration is the duration during which the allowable discharge power is less than the allowable discharge power threshold, and the first remaining power threshold is greater than the second remaining power threshold.

8. The method according to claim 1, characterized in that, The method further includes: When the temperature of the downstream switched oxygen sensor is lower than the dew point temperature, the engine control unit heats the downstream switched oxygen sensor using a first heating power. When the temperature of the downstream switched oxygen sensor is greater than or equal to the dew point temperature, the engine control unit heats the downstream switched oxygen sensor using a second heating power. Wherein, the first heating power is less than the second heating power.

9. The method according to claim 1, characterized in that, The method further includes: When the temperature of the downstream oxygen sensor is greater than or equal to a preset operating temperature threshold, the engine control unit determines the fuel injection quantity of the engine based on the difference between the target air-fuel ratio and the actual air-fuel ratio, so that the air-fuel ratio of the engine matches the optimal conversion efficiency of the three-way catalytic converter. The target air-fuel ratio is the air-fuel ratio corrected by the engine control unit based on the self-learning mode of the downstream oxygen sensor.

10. A vehicle control system, characterized in that, include: The engine control unit is used to obtain the temperature of the downstream switch oxygen sensor of the three-way catalytic converter. The engine control unit is also used to determine the target maximum permissible speed and target maximum permissible torque of the engine based on the engine coolant temperature when the temperature of the downstream switch oxygen sensor is lower than the dew point temperature, and to send a working condition coordination request to the hybrid power control unit. The hybrid power control unit is used to control the engine and the electric motor to enter a series mode according to the working condition coordination request, and to control the maximum permissible speed of the engine to be less than or equal to the target maximum permissible speed, and the maximum permissible torque of the engine to be less than or equal to the target maximum permissible torque.

11. A vehicle, characterized in that, include: The control system according to claim 10.

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

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