Method and device for keeping exhaust temperature of hybrid vehicle and hybrid vehicle
By comprehensively judging the vehicle status and controlling the catalytic converter temperature, the problem of hybrid vehicles shutting down when the exhaust temperature is low due to the need for power balance is solved, thus achieving effective purification of exhaust gas and improvement of emission performance.
Patent Information
- Application Number
- CN202511374344.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2026-01-02
AI Technical Summary
Hybrid vehicles require the engine to shut down when the exhaust temperature is low due to the need to balance the vehicle's battery charge. The catalytic converter is not hot enough to effectively purify the exhaust gas, resulting in poor emissions and strong exhaust odor, which affects the driving experience.
By acquiring vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, it determines whether to enter exhaust temperature maintenance mode and controls the catalytic converter's operating temperature to maintain it within the target temperature range, thus preventing residual exhaust gases from being insufficiently purified after shutdown.
It reduces emissions of harmful gases such as hydrocarbons and NOx, reduces exhaust odor, improves emission performance, and enhances the driving experience for passengers.
Smart Images
Figure CN121246774A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of hybrid vehicle engine control technology, and in particular to a method, device and hybrid vehicle for maintaining exhaust temperature. Background Technology
[0002] In traditional gasoline vehicle exhaust systems, because the engine is in operation for a long time, the exhaust temperature and catalytic converter temperature can be maintained at a high level, ensuring that the three-way catalytic converter is in its efficient operating temperature range, thereby achieving effective conversion of hydrocarbons, nitrogen oxides and carbon monoxide in the exhaust gas.
[0003] For hybrid vehicles, due to the frequent start-stop characteristics of their powertrain systems, the engine may shut down prematurely under certain operating conditions to achieve energy conservation and balance of power supply. If the exhaust temperature and catalytic converter temperature have not yet reached or have already fallen below the optimal catalytic reaction temperature, the residual exhaust gas after shutdown cannot be fully purified, leading to increased emissions of harmful gases such as hydrocarbons and NOx (nitrogen oxides), noticeable exhaust odor, and affecting the driving experience. Summary of the Invention
[0004] This application provides a method, device, and hybrid vehicle for maintaining exhaust temperature in hybrid vehicles, in order to solve the problems in related technologies, such as the engine shutting down when the exhaust temperature is low due to the need for overall vehicle power balance, insufficient catalytic converter temperature failing to effectively purify exhaust gas, resulting in poor emissions and strong exhaust odor, which affects the driving experience.
[0005] The first aspect of this application provides a method for maintaining the exhaust temperature of a hybrid vehicle, comprising the following steps: acquiring the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status of the hybrid vehicle; determining, based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, whether the hybrid vehicle needs to enter an exhaust temperature maintenance condition, wherein the exhaust temperature maintenance condition is a condition in which the hybrid vehicle has an exhaust temperature maintenance requirement; if it is determined that the hybrid vehicle needs to enter an exhaust temperature maintenance condition, then controlling the operating temperature of the catalytic converter of the hybrid vehicle to maintain within a target temperature range, so as to maintain the exhaust temperature of the hybrid vehicle.
[0006] Optionally, based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, it can be determined whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition, including: if the vehicle altitude is less than the altitude threshold, the engine coolant temperature is less than the coolant temperature threshold, the current vehicle speed is less than the vehicle speed threshold and continues for a preset duration, and the engine status is that the engine has been started during the driving cycle, then it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition.
[0007] Optionally, controlling the operating temperature of the catalytic converter in the hybrid vehicle to remain within a target temperature range includes: acquiring the current operating temperature of the catalytic converter and the start-up end time of the engine; determining the start-up end time of the engine based on the current time and the start-up end time; and controlling the operating temperature of the catalytic converter to remain within the target temperature range based on the current operating temperature of the catalytic converter and the start-up end time.
[0008] Optionally, based on the current operating temperature of the catalyst and the start-up end time, the operating temperature of the catalyst is controlled to be maintained within the target temperature range, including: if the current operating temperature of the catalyst is less than the temperature threshold and the start-up end time is greater than the first time threshold, then the engine heating catalyst is started; otherwise, the catalyst is not heated.
[0009] Optionally, starting the engine heating catalyst includes: obtaining the time when the engine last started request was issued; calculating the interval between the current time and the time when the last started request was issued; if the interval is longer than a second time threshold, issuing a start request to start the engine; if the interval is shorter than or equal to the second time threshold, prohibiting the issuance of a start request.
[0010] Optionally, before starting the engine heating catalyst, the method further includes: setting the engine start flag to a stop flag after the engine is stopped; if the start flag is a stop flag, setting the trigger to prevent the start request from being issued.
[0011] Optionally, if the interval duration is greater than the second duration threshold, a start request is issued to start the engine, including: if the interval duration is greater than the second duration threshold, the trigger is reset to allow the start request to be issued, and the engine is started using the start request.
[0012] Optionally, before controlling the operating temperature of the catalyst to be maintained within the target temperature range, the method further includes: obtaining a correspondence table between vehicle altitude and temperature threshold; and using vehicle altitude as an index to query the correspondence table to determine the temperature threshold.
[0013] A second aspect of this application provides a hybrid vehicle exhaust temperature maintaining device, comprising: an acquisition module for acquiring the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status of the hybrid vehicle; a judgment module for determining, based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, whether the hybrid vehicle needs to enter an exhaust temperature maintaining condition, wherein the exhaust temperature maintaining condition is a condition in which the hybrid vehicle has an exhaust temperature maintaining requirement; and a control module for controlling the operating temperature of the hybrid vehicle's catalytic converter to maintain within a target temperature range, so as to maintain the exhaust temperature of the hybrid vehicle, if it is determined that the hybrid vehicle needs to enter an exhaust temperature maintaining condition.
[0014] Optionally, the determination module is used to: determine that the hybrid vehicle needs to enter the exhaust temperature maintenance condition if the vehicle altitude is less than the altitude threshold, the engine coolant temperature is less than the coolant temperature threshold, the current vehicle speed is less than the vehicle speed threshold and continues for a preset duration, and the engine status is that the engine has been started during the driving cycle.
[0015] Optionally, the control module is used to: acquire the current operating temperature of the catalyst and the start-up end time of the engine; determine the start-up end time of the engine based on the current time and the start-up end time; and control the operating temperature of the catalyst to be maintained within the target temperature range based on the current operating temperature of the catalyst and the start-up end time.
[0016] Optionally, the control module is configured to: start the engine to heat the catalyst if the current operating temperature of the catalyst is less than the temperature threshold and the start-up end time is greater than the first duration threshold; otherwise, the catalyst is not heated.
[0017] Optionally, the control module is used to: obtain the time when the engine last started request was issued; calculate the interval between the current time and the time when the last started request was issued; if the interval is longer than a second time threshold, issue a start request to start the engine; if the interval is less than or equal to the second time threshold, prohibit issuing a start request.
[0018] Optionally, it also includes: a setting module, used to set the engine start flag to a stop flag after the engine is stopped before starting the engine heating catalyst; if the start flag is a stop flag, the trigger is set to prevent the start request from being issued.
[0019] Optionally, the reset module is used to: reset the trigger if the interval duration is greater than the second duration threshold, so as to allow the issuance of a start request and start the engine using the start request.
[0020] Optionally, it also includes: a query module, used to obtain a correspondence table between vehicle altitude and temperature threshold before controlling the operating temperature of the catalyst to be maintained within the target temperature range; and to query the correspondence table using vehicle altitude as an index to determine the temperature threshold.
[0021] A third aspect of this application provides a hybrid vehicle, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the above-described hybrid vehicle exhaust temperature maintenance method.
[0022] Therefore, this application has at least the following beneficial effects: This application's embodiments, based on information such as vehicle altitude, engine coolant temperature, vehicle speed, engine starting status, catalytic converter temperature, and engine downtime, comprehensively determine whether the engine needs to enter exhaust temperature maintenance mode. If it is determined that the hybrid vehicle needs to enter exhaust temperature maintenance mode, the operating temperature of the hybrid vehicle's catalytic converter is controlled to maintain within the target temperature range. By maintaining the catalytic converter's operating temperature, the exhaust temperature of the hybrid vehicle is maintained, preventing residual exhaust gases from being insufficiently purified after engine shutdown. This reduces emissions of harmful gases such as hydrocarbons and NOx, lowers exhaust odor, improves emission performance, and enhances the driving experience for passengers. Therefore, it solves the problems in related technologies where the engine shuts down at low exhaust temperatures due to the vehicle's battery balance requirements, resulting in insufficient catalytic converter temperature for effective exhaust gas purification, leading to poor emissions and strong exhaust odor, thus affecting the driving experience.
[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of the method for maintaining exhaust temperature of a hybrid vehicle provided in the embodiments of this application; Figure 2 This is a schematic diagram of the hybrid vehicle start-up interval control module provided in an embodiment of this application; Figure 3 This is a schematic diagram of the exhaust temperature maintenance control process for hybrid vehicles provided in the embodiments of this application; Figure 4 This is a block diagram of the hybrid vehicle exhaust temperature holding device provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the hybrid vehicle provided in the embodiments of this application. Detailed Implementation
[0025] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.
[0026] The exhaust temperature maintenance method for hybrid vehicles described in this application is applicable to HEV (hybrid electric vehicle) models. Because HEV models have relatively small battery capacities and frequent engine start-stop cycles, under certain operating conditions, the catalytic converter may be required to shut down before it has fully warmed up, or the shutdown time may be too long, causing the catalytic converter temperature to drop below its optimal reaction temperature range. If the engine is restarted in this situation, harmful gases such as hydrocarbons and nitrogen oxides in the exhaust gas will produce an unpleasant odor due to incomplete catalytic reaction, affecting the driving experience.
[0027] Furthermore, in low ambient temperatures or congested urban conditions, vehicles often crawl at low speeds or idle in place. If the battery charge is near the shutdown threshold, frequent start-stop cycles are easily triggered. When the exhaust temperature is low and the engine is ordered to shut down due to low power demand and sufficient battery charge, residual exhaust gases cannot be effectively purified, leading to increased emissions of pollutants such as NOx and CO (carbon monoxide).
[0028] Meanwhile, for hybrid vehicles using a P2 configuration, the engine needs to be started by a drive motor, which consumes electrical energy and may cause a brief interruption or jerking in power output, affecting driving stability. Therefore, while balancing vehicle drivability and battery charge balance, this application provides an exhaust temperature maintenance method. By comprehensively judging the vehicle's operating status, it intelligently decides whether to start the engine to maintain the catalytic converter's operating temperature, thereby ensuring emission performance while avoiding the impact of frequent start-stop cycles on the driving experience.
[0029] The following description, with reference to the accompanying drawings, outlines a method, apparatus, and hybrid vehicle for maintaining exhaust temperature in a hybrid vehicle according to embodiments of this application. Addressing the issue mentioned in the background art where hybrid vehicles experience engine shutdown at low exhaust temperatures due to vehicle battery balance requirements, resulting in insufficient catalytic converter temperature for effective exhaust gas purification, leading to poor emissions and strong exhaust odors, thus affecting driving comfort, this application provides a method for maintaining exhaust temperature in a hybrid vehicle. This method, based on information such as vehicle altitude, engine coolant temperature, vehicle speed, engine starting status, catalytic converter temperature, and engine shutdown time, comprehensively determines whether the engine needs to enter an exhaust temperature maintenance state. If it is determined that the hybrid vehicle needs to enter this state, the operating temperature of the catalytic converter is controlled to remain within a target temperature range. By maintaining the catalytic converter's operating temperature, the exhaust temperature of the hybrid vehicle is maintained, preventing residual exhaust gas from being insufficiently purified after engine shutdown, reducing emissions of hydrocarbons and NOx, lowering exhaust odors, improving emission performance, and enhancing the driving experience for passengers. This solves the problems in related technologies, such as the engine shutting down when the exhaust temperature is low due to the need for overall vehicle power balance, and the catalytic converter not being able to effectively purify the exhaust gas due to insufficient temperature, resulting in poor emissions and strong exhaust odor, which affects the driving experience.
[0030] Specifically, Figure 1 This is a flowchart illustrating a method for maintaining exhaust temperature in a hybrid vehicle, as provided in an embodiment of this application.
[0031] like Figure 1 As shown, the method for maintaining the exhaust temperature of a hybrid vehicle includes the following steps: In step S101, the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status of the hybrid vehicle are obtained. It is understood that vehicle altitude refers to the height of the vehicle's current geographical location relative to sea level. In this application embodiment, vehicle altitude can be obtained through an on-board atmospheric pressure sensor or a navigation system; engine water temperature refers to the real-time temperature of the engine coolant, which is measured by a temperature sensor in the engine cooling system; engine status refers to whether the engine has been started during the driving cycle, which can be determined by a status indicator. For example, if the status indicator is 1, it is determined that the engine has been started during the driving cycle; if the status indicator is 0, it is determined that the engine has not been started during the driving cycle.
[0032] Specifically, when the vehicle is in motion, this embodiment of the application collects relevant parameters in real time. For example, during driving, this embodiment of the application detects that the altitude of the vehicle's current geographical location is 300 meters; the engine coolant temperature is 70°C; the current vehicle speed is 15 km / h, and this low speed has been maintained for a period of time; at this time, the engine is in a stopped state because the power battery has sufficient charge and the power demand is small.
[0033] In step S102, based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, it is determined whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition. The exhaust temperature maintenance condition is a condition in which the hybrid vehicle has an exhaust temperature maintenance requirement.
[0034] It is understandable that due to prolonged engine downtime, low ambient temperature, or low vehicle speed, the temperature of the three-way catalytic converter may drop below its optimal reaction temperature range, reducing exhaust gas purification efficiency and posing a risk of emissions degradation and unpleasant odors. In such cases, it can be determined that hybrid vehicles have an exhaust temperature maintenance requirement to mitigate or avoid these risks. This application's embodiments can determine whether the hybrid vehicle experiences the aforementioned conditions, i.e., whether it has an exhaust temperature maintenance requirement, based on vehicle altitude, engine coolant temperature, current vehicle speed, and engine status. When it is determined that the hybrid vehicle has an exhaust temperature maintenance requirement, the vehicle is controlled to enter the exhaust temperature maintenance mode.
[0035] In some embodiments, the determination of whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition is based on the vehicle altitude, engine coolant temperature, current vehicle speed and engine status, including: if the vehicle altitude is less than the altitude threshold, the engine coolant temperature is less than the coolant temperature threshold, the current vehicle speed is less than the vehicle speed threshold and continues for a preset duration, and the engine status is that the engine has been started during the driving cycle, then it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition.
[0036] Understandably, the altitude threshold refers to a pre-set benchmark value for judging the vehicle's altitude, used to distinguish different atmospheric environmental conditions. When the actual vehicle altitude is lower than this threshold, the vehicle is considered to be operating in a low-altitude environment. The coolant temperature threshold refers to a pre-set benchmark value for judging the engine coolant temperature. When the actual engine coolant temperature is lower than this threshold, it needs to be combined with other conditions to trigger the corresponding control response. The continuous preset duration is used to confirm that the current vehicle speed is below the speed threshold for a sufficiently long period of time to avoid misjudgment due to instantaneous fluctuations. The driving cycle refers to the entire process from when the vehicle is powered on and the engine is started for the first time, to when the vehicle is turned off and the current use ends. In this driving cycle, if the power battery has sufficient charge and the engine has not yet completed its first start, the vehicle can rely entirely on pure electric mode for driving without considering exhaust emissions. To avoid accidentally triggering the exhaust temperature holding function during pure electric driving, the exhaust temperature holding mode is only allowed if the engine has completed at least one start within this driving cycle.
[0037] For example, when a vehicle is driving on an urban road at an altitude of 150 meters, the engine coolant temperature is 70°C (below the coolant temperature threshold of 80°C), the current vehicle speed is 12 km / h (below the vehicle speed threshold of 20 km / h) and has been maintained for 40 seconds, and the engine has been started once before in this driving cycle (not the first start), this application embodiment determines that all four conditions above are met, thus triggering the vehicle to enter the exhaust temperature maintenance condition.
[0038] In step S103, if it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition, the operating temperature of the catalytic converter of the hybrid vehicle is controlled to be maintained within the target temperature range in order to maintain the exhaust temperature of the hybrid vehicle.
[0039] It is understood that the target temperature range refers to the operating temperature range required for the catalytic converter to maintain efficient exhaust gas purification. Within the target temperature range, harmful gases such as hydrocarbons and nitrogen oxides in the exhaust gas can be fully converted, avoiding excessive odor and poor emissions. For example, the target temperature range is typically set between 450°C and 800°C. When the catalytic converter temperature is below 450°C, the catalytic reaction activity is insufficient, resulting in a noticeable odor in the exhaust gas; when the temperature exceeds 800°C, there is a risk of aging or melting of the catalytic converter material. Therefore, this application embodiment controls the operating temperature of the catalytic converter in the hybrid vehicle to maintain the exhaust temperature of the hybrid vehicle, avoiding excessive odor and poor emissions.
[0040] In some embodiments, controlling the operating temperature of the catalyst in a hybrid vehicle to remain within a target temperature range includes: acquiring the current operating temperature of the catalyst and the start-up end time of the engine; determining the start-up end duration of the engine based on the current time and the start-up end time; and controlling the operating temperature of the catalyst to remain within the target temperature range based on the current operating temperature of the catalyst and the start-up end duration.
[0041] Among them, the engine start-up end time refers to the moment when the engine stops running and enters the shutdown state; the start-up end time refers to the time interval from when the engine stops running to the current moment.
[0042] It is understood that the embodiments of this application can comprehensively realize the control of the catalyst's operating temperature based on the current operating temperature of the catalyst and the start-up and end times. By taking into account multiple factors, the operating temperature of the catalyst can be maintained within the target temperature range, thereby improving the control accuracy of the catalyst's operating temperature.
[0043] In some embodiments, controlling the operating temperature of the catalyst to remain within a target temperature range based on the current operating temperature of the catalyst and the start-up end time includes: if the current operating temperature of the catalyst is less than a temperature threshold and the start-up end time is greater than a first time threshold, then starting the engine to heat the catalyst; otherwise, not heating the catalyst.
[0044] Understandably, the first duration threshold refers to the engine shutdown duration threshold, used to determine whether the engine shutdown time is too long, in order to determine whether the catalytic converter temperature may be below the effective operating range. For example, if the first duration threshold is set to 600 seconds, if the current operating temperature of the catalytic converter is below 450°C and the start-up end time has reached 800 seconds, the heating conditions have been met, and the engine will be triggered to actively start to heat the catalytic converter. If the start-up end time is 300 seconds, since the start-up end time is below the first duration threshold, even if the current operating temperature of the catalytic converter is below the temperature threshold, the engine will not start, thus avoiding frequent starts under short-term shutdown conditions.
[0045] Specifically, controlling the catalytic converter's operating temperature within the target temperature range includes not only starting the engine to heat it when the catalytic converter's operating temperature is below the temperature threshold, but also actively delaying the execution of the engine shutdown command when the engine is running and the catalytic converter temperature is low, extending the engine's running time, and using its exhaust heat to continuously heat the catalytic converter, thereby avoiding temperature fluctuations caused by frequent start-stop cycles.
[0046] It should be noted that the catalytic converter temperature has a wide impact on exhaust odor, and therefore has a relatively low priority in determining the necessity of starting the engine. Thus, the heating request is only triggered when a comprehensive assessment confirms its necessity, balancing emissions performance and driving experience.
[0047] In some embodiments, before controlling the operating temperature of the catalyst to be maintained within the target temperature range, the method further includes: obtaining a correspondence table between vehicle altitude and temperature threshold; and querying the correspondence table using vehicle altitude as an index to determine the temperature threshold.
[0048] Among them, the temperature threshold refers to a pre-calibrated temperature critical value that dynamically changes with the vehicle's altitude. It is used to determine whether the catalytic converter needs to be heated. When the catalytic converter's operating temperature is lower than this threshold, it is considered that there is a need to maintain the exhaust temperature. The correspondence table is used to adjust this temperature threshold according to the vehicle's altitude to adapt to the changing characteristics of engine exhaust temperature at different altitudes.
[0049] For example, if the corresponding table is set as follows: 450°C for altitudes of 0-500 meters; 480°C for altitudes of 1500-2000 meters; and 510°C for altitudes above 3000 meters, when a vehicle travels to an area at an altitude of 1800 meters, the system will look up the table using the current altitude as an index to determine the temperature threshold as 480°C.
[0050] In some embodiments, starting the engine heating catalyst includes: obtaining the time when the engine last start request was issued; calculating the interval between the current time and the time when the last start request was issued; if the interval is longer than a second time threshold, issuing a start request to start the engine; if the interval is shorter than or equal to the second time threshold, prohibiting the issuance of a start request.
[0051] The second duration threshold refers to the minimum permissible time interval between two engine start requests to prevent frequent engine start-stop cycles caused by catalytic converter temperature fluctuations. For example, if the second duration threshold is set to 300 seconds, and the previous start request occurred 200 seconds before the current time, then even if the catalytic converter temperature is below the set threshold, a new start request will be prohibited to avoid repeated engine start-stop cycles within a short period of time. When the interval exceeds 300 seconds, a new start request is allowed.
[0052] In some embodiments, before starting the engine heating catalyst, the method further includes: setting the engine start flag to a stop flag after the engine is stopped; if the start flag is a stop flag, setting a trigger to prevent a start request from being issued.
[0053] The start flag indicates whether the engine is currently allowed to start, and its values include running flag and stop flag; the stop flag indicates that the engine is temporarily prohibited from starting due to a stop; the trigger is used to implement the locking function of the start request, and when set, it blocks the issuance of the start request.
[0054] In some embodiments, if the interval duration is greater than a second duration threshold, a start request is issued to start the engine, including: if the interval duration is greater than the second duration threshold, resetting the trigger to allow the start request to be issued, and using the start request to start the engine.
[0055] Among them, trigger reset means to remove the prohibition state of start request, so that the system can resume its ability to respond to heating demand.
[0056] Specifically, such as Figure 2 As shown in the embodiment of this application, when the output signal requiring catalyst heating is needed, the engine shutdown event is detected by the RS trigger (start flag changes from 1 to 0), and the trigger is then set to block subsequent heating start requests; after a preset time delay, the trigger is reset to restore the ability to respond to catalyst heating requests, thereby ensuring that the time interval between two engine starts meets the minimum requirement and ensuring the smoothness of the driving process.
[0057] For example, if the vehicle's current altitude is 1500 meters, and the temperature threshold of 300°C is obtained from a table based on the current altitude of 1500 meters, if the current temperature of the catalytic converter is 280°C, which is lower than the temperature threshold of 300°C, and the engine shutdown time reaches 65 seconds, exceeding the first duration threshold of 60 seconds, this embodiment of the application outputs a signal indicating that the catalytic converter needs to be heated. If the engine start flag changes from "1" to "0" at this time, the RS trigger is immediately set, blocking engine start requests related to catalytic converter heating. During the period when the trigger is set, new start requests are prohibited. After a 60-second delay from the time the engine stops, the trigger is reset, restoring the ability to respond to heating start requests, ensuring that the time interval between two adjacent engine starts is not less than 60 seconds, so as to avoid frequent start-stop.
[0058] Specifically, such as Figure 3As shown, the exhaust temperature maintenance control process for hybrid vehicles includes: First, a comprehensive judgment is made on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status. When the vehicle altitude is lower than a set threshold, the engine coolant temperature is lower than a coolant temperature threshold, the current vehicle speed is lower than a speed threshold and this condition is maintained for a preset duration, and the engine is not starting for the first time in this driving cycle, it is determined that the conditions for entering the exhaust temperature maintenance condition are met. Subsequently, the target temperature threshold of the catalytic converter is corrected according to the current vehicle altitude, and the corrected threshold is compared with the actual catalytic converter temperature. If the catalytic converter temperature is lower than the corrected threshold, a catalytic converter heating demand signal is generated. Before outputting the engine start request, the start interval control module must also judge to ensure that more than 60 seconds have passed since the last start request to avoid frequent starts. If the interval requirement is met, the start request is allowed to be issued to increase the exhaust temperature and maintain the catalytic converter efficiency. If any condition is not met, the exhaust temperature maintenance condition is not entered.
[0059] For example, when a vehicle is traveling at an altitude of 100 m, an engine coolant temperature of 75 ℃, and a speed of 18 km / h for 40 seconds, and the engine is not starting for the first time during this driving cycle, this embodiment determines that the conditions for entering the catalytic converter temperature maintenance condition are met. Based on the current altitude, the target temperature threshold for the catalytic converter is corrected to 290 ℃. If the current temperature of the catalytic converter is detected to be 270 ℃, which is lower than the corrected threshold, a signal is output that the catalytic converter needs to be heated. If the engine has just stopped, the start flag changes from "1" to "0", the trigger is set, and the heating start request is blocked. After a 60-second delay, the trigger resets, allowing the start request to be issued again. The engine responds by starting to heat the catalytic converter, thereby ensuring emission performance while avoiding frequent start-stop cycles.
[0060] The hybrid vehicle exhaust temperature maintenance method proposed in this application identifies information such as vehicle altitude, engine coolant temperature, vehicle speed, engine starting status, catalytic converter temperature, and engine shutdown time. It comprehensively determines whether the engine needs to enter exhaust temperature maintenance mode. If it is determined that the hybrid vehicle needs to enter exhaust temperature maintenance mode, the operating temperature of the catalytic converter is controlled to remain within the target temperature range. This maintains the exhaust temperature of the hybrid vehicle, preventing residual exhaust gases from being insufficiently purified after engine shutdown, reducing emissions of hydrocarbons and NOx, lowering exhaust odor, improving emission performance, and enhancing the driving experience. Therefore, it solves the problems in related technologies where the engine shuts down at low exhaust temperatures due to the vehicle's battery balance requirements, resulting in insufficient catalytic converter temperature for effective exhaust gas purification, leading to poor emissions and strong exhaust odor, thus affecting the driving experience.
[0061] Next, referring to the accompanying drawings, a hybrid vehicle exhaust temperature maintaining device according to an embodiment of this application is described.
[0062] Figure 4 This is a block diagram of a hybrid vehicle exhaust temperature maintaining device according to an embodiment of this application.
[0063] like Figure 4 As shown, the hybrid vehicle exhaust temperature holding device 10 includes: an acquisition module 100, a judgment module 200, and a control module 300.
[0064] The acquisition module 100 is used to acquire the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status of the hybrid vehicle; the judgment module 200 is used to determine whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, wherein the exhaust temperature maintenance condition is a condition in which the hybrid vehicle has an exhaust temperature maintenance requirement; the control module 300 is used to control the operating temperature of the hybrid vehicle's catalytic converter to maintain within the target temperature range if it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition, so as to maintain the exhaust temperature of the hybrid vehicle.
[0065] In some embodiments, the determination module is used to: determine that the hybrid vehicle needs to enter the exhaust temperature maintenance condition if the vehicle altitude is less than the altitude threshold, the engine water temperature is less than the water temperature threshold, the current vehicle speed is less than the vehicle speed threshold and continues for a preset time, and the engine status is that the engine has been started during the driving cycle.
[0066] In some embodiments, the control module is configured to: acquire the current operating temperature of the catalyst and the start-up end time of the engine; determine the start-up end time of the engine based on the current time and the start-up end time; and control the operating temperature of the catalyst to be maintained within a target temperature range based on the current operating temperature of the catalyst and the start-up end time.
[0067] In some embodiments, the control module is configured to: start the engine to heat the catalyst if the current operating temperature of the catalyst is less than a temperature threshold and the start-up end time is greater than a first duration threshold; otherwise, not heat the catalyst.
[0068] In some embodiments, the control module is configured to: obtain the time when the engine last started request was issued; calculate the interval between the current time and the time when the last started request was issued; if the interval is longer than a second time threshold, issue a start request to start the engine; if the interval is shorter than or equal to the second time threshold, prohibit issuing a start request.
[0069] In some embodiments, the system further includes: a setting module, configured to set the engine start flag to a stop flag after the engine has stopped, before starting the engine heating catalyst; and to set the trigger if the start flag is a stop flag, so as to prevent the issuance of a start request.
[0070] In some embodiments, the reset module is configured to: reset the trigger if the interval duration is greater than a second duration threshold, so as to allow a start request to be issued and to start the engine using the start request.
[0071] In some embodiments, the system further includes: a query module, configured to obtain a table of correspondences between vehicle altitude and temperature thresholds before controlling the operating temperature of the catalyst to be maintained within a target temperature range; and to query the table of correspondences using vehicle altitude as an index to determine the temperature threshold.
[0072] It should be noted that the foregoing explanation of the hybrid vehicle exhaust temperature holding method embodiment also applies to the hybrid vehicle exhaust temperature holding device of this embodiment, and will not be repeated here.
[0073] The hybrid vehicle exhaust temperature holding device proposed in this application comprehensively determines whether the engine needs to enter the exhaust temperature holding condition based on information such as vehicle altitude, engine coolant temperature, vehicle speed, engine starting status, catalytic converter temperature, and engine shutdown time. If it is determined that the hybrid vehicle needs to enter the exhaust temperature holding condition, the device controls the operating temperature of the hybrid vehicle's catalytic converter to be maintained within the target temperature range. By maintaining the operating temperature of the catalytic converter, the exhaust temperature of the hybrid vehicle is maintained, preventing residual exhaust gas from being insufficiently purified after engine shutdown. This reduces emissions of harmful gases such as hydrocarbons and NOx, reduces exhaust odor, improves emission performance, and enhances the driving experience for passengers. Therefore, it solves the problems in related technologies where the engine shuts down at a low exhaust temperature due to the vehicle's battery balance requirements, resulting in insufficient catalytic converter temperature for effective exhaust gas purification, leading to poor emissions and strong exhaust odor, which negatively impacts the driving experience.
[0074] Figure 5 This is a schematic diagram of the structure of a hybrid vehicle provided in an embodiment of this application. The hybrid vehicle may include: The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.
[0075] When processor 502 executes the program, it implements the hybrid vehicle exhaust temperature maintenance method provided in the above embodiments.
[0076] Furthermore, hybrid vehicles also include: Communication interface 503 is used for communication between memory 501 and processor 502.
[0077] The memory 501 is used to store computer programs that can run on the processor 502.
[0078] The memory 501 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.
[0079] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.
[0080] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.
[0081] The processor 502 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of this application.
[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0084] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.
[0085] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.
[0086] Those skilled in the art will understand that all or part of the steps of the methods implementing the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.
[0087] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. A method for maintaining exhaust temperature in a hybrid vehicle, characterized in that, Includes the following steps: Obtain the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status of the hybrid vehicle; Based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status, determine whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition, wherein the exhaust temperature maintenance condition is a condition in which the hybrid vehicle has an exhaust temperature maintenance requirement. If it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition, the operating temperature of the catalytic converter of the hybrid vehicle is controlled to be maintained within the target temperature range in order to maintain the exhaust temperature of the hybrid vehicle.
2. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 1, characterized in that, The step of determining whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition based on the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status includes: If the vehicle altitude is less than the altitude threshold, the engine coolant temperature is less than the coolant temperature threshold, the current vehicle speed is less than the vehicle speed threshold for a preset duration, and the engine status is that the engine has been started during the driving cycle, then it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition.
3. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 1, characterized in that, Maintaining the operating temperature of the catalytic converter in the hybrid vehicle within a target temperature range includes: Obtain the current operating temperature of the catalyst and the start-up and end times of the engine; The start-up end time of the engine is determined based on the current time and the start-up end time; Based on the current operating temperature of the catalyst and the duration of the start-up, the operating temperature of the catalyst is controlled to be maintained within the target temperature range.
4. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 3, characterized in that, The step of controlling the operating temperature of the catalyst to remain within the target temperature range based on the current operating temperature of the catalyst and the duration of the start-up termination includes: If the current operating temperature of the catalyst is less than a temperature threshold and the start-up end time is greater than a first duration threshold, then the engine is started to heat the catalyst; otherwise, the catalyst is not heated.
5. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 4, characterized in that, The step of starting the engine to heat the catalyst includes: Obtain the time when the engine last started; Calculate the time interval between the current time and the time when the last start request was sent; If the interval duration is greater than the second duration threshold, a start request is issued to start the engine; if the interval duration is less than or equal to the second duration threshold, the start request is prohibited.
6. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 5, characterized in that, Before starting the engine to heat the catalyst, the following is also included: After the engine stops, the engine start flag is set to a stop flag; If the start flag is the stop flag, then the trigger is set to prevent the start request from being issued.
7. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 6, characterized in that, The step of issuing a start request to start the engine if the interval duration is greater than the second duration threshold includes: If the interval duration is greater than the second duration threshold, the trigger is reset to allow the start request to be issued, and the engine is started using the start request.
8. The method for maintaining exhaust temperature in a hybrid vehicle according to claim 4, characterized in that, Before controlling the operating temperature of the catalyst to be maintained within the target temperature range, the method further includes: Obtain the correspondence table between the vehicle altitude and the temperature threshold; Using the vehicle altitude as an index, the temperature threshold is determined by querying the corresponding table.
9. A hybrid vehicle exhaust temperature maintaining device, characterized in that, include: The acquisition module is used to acquire the vehicle altitude, engine coolant temperature, current vehicle speed, and engine status of the hybrid vehicle. The judgment module is used to determine whether the hybrid vehicle needs to enter the exhaust temperature maintenance condition based on the vehicle altitude, the engine coolant temperature, the current vehicle speed and the engine status, wherein the exhaust temperature maintenance condition is the condition in which the hybrid vehicle has an exhaust temperature maintenance requirement. The control module is used to control the operating temperature of the catalytic converter of the hybrid vehicle to be maintained within a target temperature range when it is determined that the hybrid vehicle needs to enter the exhaust temperature maintenance condition, so as to maintain the exhaust temperature of the hybrid vehicle.
10. A hybrid vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the hybrid vehicle exhaust temperature maintenance method according to any one of claims 1-8.