Control method of rear oxygen sensor, vehicle and product

Abstract

The embodiment of the invention is suitable for the technical field of vehicles, and provides a control method of a rear oxygen sensor, a vehicle and a product, and the method comprises the steps that in the current driving cycle, starting and stopping information of an engine when a hybrid vehicle runs is obtained; determining start-stop working conditions of the engine based on the start-stop information; when the start-stop working condition is a frequent start-stop working condition, a heating voltage control strategy of the rear oxygen sensor is switched from a first strategy to a second strategy; when the rear oxygen sensor is in the same working scene, the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy; and adjusting the heating voltage of the rear oxygen sensor based on a second strategy. By adopting the method, the failure rate of the oxygen sensor when the engine is frequently started and stopped can be reduced.

Description

Technical Field

[0001] The present application belongs to the field of vehicle technology, and in particular, relates to a control method, vehicle and product of a rear oxygen sensor. Background Art

[0002] In order to meet automobile emission regulations, rear oxygen sensors have become standard equipment for hybrid vehicles to monitor the oxygen concentration in exhaust gas. However, in actual scenarios, when hybrid vehicles are driving, if the engine is frequently started and stopped, the exhaust gas from incomplete combustion will continue to pollute the rear oxygen sensor, causing it to fail to work properly.

[0003] At present, in the prior art, a fault prompt is usually given after the rear oxygen sensor is contaminated or fails to remind the car owner to replace it, and there is no control strategy for the rear oxygen sensor after it is contaminated. As a result, the failure rate of the rear oxygen sensor is relatively high. Summary of the invention

[0004] The embodiments of the present application provide a control method, a vehicle and a product for a rear oxygen sensor, which can solve the problem that the prior art lacks a good control strategy to control the rear oxygen sensor to reduce the high failure rate of the rear oxygen sensor.

[0005] In a first aspect, an embodiment of the present application provides a control method for a rear oxygen sensor, the method comprising:

[0006] In the current driving cycle, the start and stop information of the engine of the hybrid vehicle is obtained;

[0007] determining a start-stop operating condition of the engine based on the start-stop information;

[0008] When the start-stop condition is a frequent start-stop condition, the heating voltage control strategy of the rear oxygen sensor is switched from the first strategy to the second strategy; under the same working scenario, the heating voltage determined by the second strategy of the rear oxygen sensor is greater than or equal to the heating voltage determined by the first strategy;

[0009] A heater voltage of the rear oxygen sensor is adjusted based on a second strategy.

[0010] In one embodiment, the start-stop information includes the number of start-stop times; obtaining the start-stop information of the engine when the hybrid vehicle is traveling includes:

[0011] When the engine switches from a start state to a stop state, exhaust gas information at the rear oxygen sensor is obtained;

[0012] The number of starts and stops is determined based on exhaust gas information.

[0013] In one embodiment, determining the number of starts and stops based on exhaust gas information includes:

[0014] Determine the fuel combustion status of the engine based on the exhaust information;

[0015] If the fuel combustion condition is that the fuel is fully burned, the number of starts and stops remains unchanged;

[0016] If the fuel combustion condition is that the fuel is not fully burned, the current start-stop number is added to the preset value to obtain the updated start-stop number.

[0017] In one embodiment, the exhaust gas information includes at least one of the exhaust gas temperature and the content of combustion byproducts; and determining the fuel combustion condition of the engine based on the exhaust gas information includes:

[0018] If the exhaust gas temperature is less than or equal to the preset temperature, and / or the content of the combustion byproducts is greater than the preset content, it is determined that the fuel combustion condition is that the fuel is not fully burned;

[0019] If the exhaust gas temperature is greater than the preset temperature, and the content of combustion by-products is less than or equal to the preset content, it is determined that the fuel combustion condition is complete combustion of the fuel.

[0020] In one embodiment, the start-stop information includes the number of start-stop times; determining the start-stop operating condition of the engine based on the start-stop information includes:

[0021] If the number of starts and stops is greater than the preset number, the start-stop condition is determined to be a frequent start-stop condition;

[0022] If the start-stop number is less than or equal to the preset number, the start-stop condition is determined to be a normal start-stop condition.

[0023] In one embodiment, the start-stop information includes the interval between each start and stop of the engine; determining the start-stop operating condition of the engine based on the start-stop information further includes:

[0024] Determine the average duration of multiple intervals;

[0025] If the average duration is less than or equal to the preset duration, the start-stop condition is determined to be a frequent start-stop condition;

[0026] If the average duration is greater than the preset duration, the start-stop condition is determined to be a normal start-stop condition.

[0027] In one embodiment, the method further includes:

[0028] At the beginning of each driving cycle, the heating voltage is determined based on the first strategy, and the target step and the steps after the target step are executed; the target step includes obtaining the start and stop information of the engine when the hybrid vehicle is driving.

[0029] In one embodiment, the first strategy and the second strategy are respectively used to describe the corresponding relationship between the exhaust gas temperature at the rear oxygen sensor and the heating voltage; wherein, under the same exhaust gas temperature, the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature.

[0030] In a second aspect, an embodiment of the present application provides a control device for a rear oxygen sensor, the device comprising:

[0031] An acquisition module, used for acquiring engine start and stop information of a hybrid vehicle during driving in a current driving cycle;

[0032] A determination module, used to determine the start-stop working condition of the engine based on the start-stop information;

[0033] A switching module, used for switching the heating voltage control strategy of the rear oxygen sensor from the first strategy to the second strategy when the start-stop working condition is a frequent start-stop working condition; the heating voltage determined from the second strategy of the rear oxygen sensor under the same working scenario is greater than or equal to the heating voltage determined from the first strategy;

[0034] The regulating module is configured to regulate a heating voltage of the rear oxygen sensor based on a second strategy.

[0035] In a third aspect, an embodiment of the present application provides a vehicle, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method of the first aspect described above when executing the computer program.

[0036] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method of the first aspect described above is implemented.

[0037] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a vehicle, enables the vehicle to execute the method of the first aspect.

[0038] Compared with the prior art, the embodiments of the present application have the following beneficial effects: in the current driving cycle, the start-stop information of the engine when the hybrid vehicle is driving can be obtained to determine the start-stop working condition of the engine based on the start-stop information. When the start-stop working condition is a frequent start-stop working condition, it can be considered that the frequent start-stop of the engine may cause the fuel to be not fully burned, so that the oil produced by the incomplete combustion adheres to the rear oxygen sensor, causing pollution to the rear oxygen sensor. Based on this, in order to protect the rear oxygen sensor, the heating voltage control strategy of the rear oxygen sensor can be switched from the first strategy to the second strategy when the start-stop working condition is a frequent start-stop working condition. Among them, since the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same conditions, when the heating voltage of the rear oxygen sensor is adjusted based on the second strategy, the temperature of the rear oxygen sensor when operating based on the heating voltage will be greater than or equal to the temperature when operating based on the heating voltage determined based on the first strategy. Furthermore, the rear oxygen sensor can decompose and volatilize the exhaust oil attached to the surface based on a higher heating temperature, stabilize the performance of the internal sensor element, enable the rear oxygen sensor to restore its function at high temperature, and reduce the failure rate of the rear oxygen sensor. Furthermore, determining the heating voltage based on the second strategy can also make the determined heating voltage more reasonable than the subjectively set heating voltage. Further, energy saving can be achieved to the greatest extent while ensuring that the rear oxygen sensor can recover its function at high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 is a flow chart of a control method for a rear oxygen sensor provided in one embodiment of the present application;

[0041] Figure 2 is a flow chart of a control method for a rear oxygen sensor provided by another embodiment of the present application;

[0042] Figure 3 is a structural schematic diagram of a control device for a rear oxygen sensor provided by an embodiment of the present application;

[0043] Figure 4 It is a structural schematic diagram of a vehicle provided in one embodiment of the present application. DETAILED DESCRIPTION

[0044] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0045] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0046] It should be noted that the information collection process (such as face image collection process, fingerprint information collection process, etc.) / feature extraction process involved in this application is performed with the user's knowledge and permission, that is, the information collection process / feature extraction process complies with the requirements of laws and regulations and does not constitute an act that harms the public interest.

[0047] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0048] In order to meet automobile emission regulations, rear oxygen sensors have become standard equipment for hybrid vehicles to monitor the oxygen concentration in exhaust gas. However, in actual scenarios, when hybrid vehicles are driving, if the engine is frequently started and stopped, the exhaust gas from incomplete combustion will continue to pollute the rear oxygen sensor, causing it to fail to work properly.

[0049] For example, there are some active substances involved in sensing oxygen concentration on the surface of the ceramic sensitive element in the rear oxygen sensor. When contaminated by exhaust oil from incomplete combustion, the activity of the active substances will be inhibited, causing the ability to chemically react with oxygen molecules in the exhaust gas to decrease, thereby affecting the accurate detection of oxygen concentration changes by the rear oxygen sensor.

[0050] At present, in the prior art, a fault prompt is usually given after the rear oxygen sensor is contaminated and fails to remind the car owner to replace it, and there is no strategy for controlling the rear oxygen sensor after it is contaminated.

[0051] Based on this, in order to protect the rear oxygen sensor and reduce the failure rate of the rear oxygen sensor under the condition of frequent engine start and stop, the embodiment of the present application provides a control method for the rear oxygen sensor, which can be applied to hybrid vehicles. For example, on electronic devices such as the vehicle controller and central controller on the hybrid vehicle, the embodiment of the present application does not impose any restrictions on the specific type of electronic equipment.

[0052] See also Figure 1 , Figure 1 The following is a flowchart of a control method for a rear oxygen sensor according to an embodiment of the present application. The method comprises the following steps:

[0053] S101. In a current driving cycle, obtaining start / stop information of an engine of a hybrid vehicle when the hybrid vehicle is driving.

[0054] In one embodiment, a driving cycle generally refers to a complete process of a hybrid vehicle starting from startup, going through a series of operating states (such as acceleration, deceleration, constant speed driving, etc.), until finally stopping and shutting down. A driving cycle can be considered as a complete use stage of a hybrid vehicle.

[0055] Therefore, the current driving cycle can be considered to refer to a driving cycle that the hybrid vehicle is currently undergoing, which is different from a driving cycle that has been completed before or a driving cycle that will occur in the future.

[0056] In one embodiment, the hybrid vehicle is a hybrid electric vehicle, which combines the advantages of a traditional fuel engine and an electric drive system, and has two power sources, a fuel engine and an electric motor, which can work together according to different working conditions. For example, when the hybrid vehicle starts and travels at a low speed, it can be driven by an electric motor to achieve zero emissions and low noise; when traveling at a high speed and requiring a large power output, the fuel engine can intervene or the two can work together.

[0057] It is understandable that since a hybrid vehicle has two sources of power, the engine can be started and stopped frequently during a driving cycle.

[0058] In one embodiment, the start-stop information includes but is not limited to the number of engine starts and stops, the interval between each start and stop, the temperature and speed of the engine, etc., which are not limited to this.

[0059] It should be noted that, since it is necessary to determine whether the start-stop condition of the engine is a frequent start-stop condition based on the start-stop information, for the convenience of explanation, at least one of the start-stop number and the interval duration can be used as the above-mentioned start-stop information.

[0060] It can be considered that when the engine speed increases from 0 or when an engine start command is received, the engine is determined to be started. And when the engine speed decreases to 0 or when an engine stop command is received, the engine is determined to be stopped. In this embodiment, the method for determining the start and stop of the engine is not limited.

[0061] In one embodiment, the hybrid vehicle can count the total number of times the engine starts from a stationary state and then stops running in the current driving cycle, and determine the total number as the start-stop number. Among them, one start-stop number consists of one start and one stop of the engine. Alternatively, it can be considered that one stop of the engine must be accompanied by one start of the engine. Therefore, the start-stop number can also be considered as the number of stops of the engine. In this embodiment, the statistical method of the start-stop number is not limited.

[0062] For example, in a driving cycle of urban congested traffic, hybrid vehicles are often prone to hybrid vehicle congestion, waiting for traffic lights, etc. As a result, the engine may be frequently started and stopped. In this case, the number of starts and stops is usually relatively large. Also, for a driving cycle of smooth driving on a highway, the engine may continue to run for a long time after starting. In this case, the number of starts and stops is usually relatively small.

[0063] Furthermore, the hybrid vehicle can use the time length between each engine stop and the next start, or the time length between each engine start and stop (i.e., the running time after the engine is started) as the above interval time. In this embodiment, the time length between each engine start and stop can be used as the above interval time.

[0064] For example, a hybrid vehicle stops at a red light in a city, the engine stops working, and the engine starts again when the green light comes on. At this time, after the engine is started and the hybrid vehicle drives normally to the intersection, if the intersection is red, the difference between the time when the engine is started and the time when the hybrid vehicle drives to the intersection can be considered as the above-mentioned interval time.

[0065] Based on the above description, it can be considered that the number of starts and stops and the interval duration can, to a certain extent, reflect whether the engine is started and stopped frequently.

[0066] S102: Determine the start-stop operating condition of the engine based on the start-stop information.

[0067] In one embodiment, the above-mentioned start-stop condition includes a frequent start-stop condition and a normal start-stop condition. It is understandable that when the engine is in a frequent start-stop condition, it can be considered that the engine runs for a short time after each start, so that the fuel is insufficient when the engine is running and a large amount of oil pollution is generated. At this time, a large amount of oil pollution will seriously pollute the rear oxygen sensor.

[0068] Also, when the engine is in a normal start-stop condition, it can be considered that the engine runs for a long time after each start, so that the fuel is fully burned when the engine is running without or with a small amount of oil pollution. Therefore, the rear oxygen sensor will not be polluted under normal start-stop conditions.

[0069] Based on the above description, it can be considered that the frequent start-stop condition is a start-stop condition that easily generates a large amount of oil pollution to pollute the rear oxygen sensor. And the normal start-stop condition is a start-stop condition that will not pollute the rear oxygen sensor.

[0070] Based on the above explanation of the start-stop information, as an example, the hybrid vehicle can determine the average duration of multiple intervals. Then, when the average duration is less than or equal to the preset duration, the start-stop condition is determined to be a frequent start-stop condition. Otherwise, when the average duration is greater than the preset duration, the start-stop condition is determined to be a normal start-stop condition.

[0071] In one embodiment, the preset time length can be set according to actual conditions, and is not limited thereto. For example, the preset time length can be 3 minutes.

[0072] It is understandable that if the engine stops running within a short time after each start, it can be considered that the fuel cannot be fully burned effectively due to the short engine running time and low temperature inside the engine. Therefore, a large amount of oil pollution will be generated every time the engine is started and stopped, which pollutes the rear oxygen sensor. Based on this, when the average duration is less than or equal to the preset duration, the start-stop condition can be determined as a frequent start-stop condition that is prone to generate oil pollution and pollute the rear oxygen sensor.

[0073] Specifically, after the engine is started, it usually takes a certain amount of time for the engine temperature to reach the normal operating temperature. At this time, when the engine temperature is low, the fuel cannot be evenly mixed with the air after being injected into the cylinder. In addition, when the engine is started, the engine control system usually injects a relatively large amount of fuel in order to enable the engine to reach the normal operating temperature as quickly as possible. Therefore, this will also increase the possibility of incomplete combustion of the fuel. Based on this, it can be considered that when the interval time is short (for example, less than or equal to the preset time), the fuel cannot be fully burned.

[0074] In addition, based on the above description, when the average duration is less than or equal to the preset duration, it can be considered that the running duration after each engine start is short. Furthermore, in the scenario where the fuel cannot be fully burned for multiple times, the degree of contamination of the rear oxygen sensor will be further increased.

[0075] Based on this, by comparing the average duration with the preset duration to judge the start-stop condition, the degree of contamination of the rear oxygen sensor by the engine start-stop information can be determined more objectively and accurately. Furthermore, it can provide a reliable basis for the subsequent adjustment of the heating voltage control strategy of the rear oxygen sensor and improve the accuracy of the adjustment of the heating voltage control strategy.

[0076] In another embodiment, the hybrid vehicle may further determine that the start-stop condition is a frequent start-stop condition when the number of start-stop times is greater than a preset number, otherwise, the start-stop condition is determined to be a normal start-stop condition when the number of start-stop times is less than or equal to the preset number.

[0077] In one embodiment, the above-mentioned preset number of times can be set according to actual conditions, and no limitation is made to this. For example, the above-mentioned preset number of times can be 7 times.

[0078] It is understandable that when the number of starts and stops is greater than the preset number, it can be considered that the possibility of insufficient fuel in the engine will increase. Furthermore, when the possibility of insufficient fuel increases, the possibility of the rear oxygen sensor being contaminated will also increase, until the degree of contamination increases and the rear oxygen sensor fails.

[0079] Based on this, it can be considered that the number of starts and stops can accurately reflect whether the hybrid vehicle is in a frequent start-stop condition that is prone to generate a large amount of oil pollution to the rear oxygen sensor. It can also provide a reliable basis for the subsequent adjustment of the heating voltage control strategy of the rear oxygen sensor, thereby improving the accuracy of the adjustment of the heating voltage control strategy.

[0080] In another embodiment, the hybrid vehicle may also determine that the start-stop condition is a frequent start-stop condition when the number of start-stop times is greater than a preset number and / or the average duration is less than or equal to a preset duration. That is, when any start-stop information meets the corresponding determination condition, it is determined that the engine is in a frequent start-stop condition. Otherwise, when the number of start-stop times is less than or equal to a preset number and the average duration is greater than a preset duration, the start-stop condition is determined to be a normal start-stop condition.

[0081] Based on this, compared to the shortcoming that only relying on single start-stop information may not accurately reflect the actual start-stop conditions, combining the number of start-stop times and the average duration to determine the start-stop conditions can achieve a comprehensive consideration of the start-stop conditions from different angles, making the judgment of the actual start-stop conditions of the engine more comprehensive and accurate.

[0082] It should be noted that each time the engine is started and stopped, the possibility of determining that the engine is insufficiently fueled increases, and it is impossible to accurately determine whether the rear oxygen sensor is definitely contaminated by oil when the engine is insufficiently fueled after each start and stop. Therefore, if the number of starts and stops determined based on the start and stop of the engine is used to determine whether the hybrid vehicle is in a frequent start-stop condition that is prone to generate a large amount of oil pollution to the rear oxygen sensor, there may be a certain amount of misidentification.

[0083] Based on this, in order to accurately determine the number of engine starts and stops, so as to improve the recognition accuracy of the start-stop conditions based on the number of start-stop times, the hybrid vehicle can also obtain the exhaust gas information at the rear oxygen sensor when the engine switches from the start state to the stop state, so as to determine the number of starts and stops based on the exhaust gas information.

[0084] In one embodiment, the exhaust gas information includes at least one of the exhaust gas temperature and the content of combustion by-products, which is not limited thereto.

[0085] It should be noted that when the engine fuel is fully burned, the exhaust temperature is usually greater than the preset temperature, wherein the preset temperature can be set according to actual conditions and is not limited thereto.

[0086] For example, when a hybrid vehicle is driving at high speed or climbing a hill, the engine will run at high load. At this time, the hybrid vehicle needs more fuel to burn to provide power. Therefore, under the above driving conditions, the heat generated when the fuel is fully burned will increase significantly, and the exhaust temperature will increase accordingly.

[0087] Also, when the hybrid vehicle is in idling or low-load driving conditions, the engine will run at low load. At this time, the hybrid vehicle does not need to burn a large amount of fuel to provide power. Furthermore, under the above driving conditions, when the fuel is fully burned, the exhaust gas temperature will also rise, but the increase is relatively low.

[0088] Based on this, the above-mentioned preset temperatures can be set in multiples, and each preset temperature can correspond to a driving condition of a hybrid vehicle, so that judging the fuel combustion condition based on the preset temperature is more accurate and practical.

[0089] Furthermore, the above combustion byproducts include, but are not limited to, carbon monoxide and hydrocarbons, etc. It is understandable that when the engine fuel is not fully burned, the corresponding content of the above combustion byproducts will increase significantly.

[0090] Based on this, the hybrid vehicle can determine that the fuel combustion condition is incomplete combustion when the content of combustion byproducts is greater than a preset content. Otherwise, when the content of combustion byproducts is less than or equal to the preset content, the fuel combustion condition is determined to be complete combustion.

[0091] The above-mentioned preset content can be set according to actual conditions, and the preset content corresponding to different combustion by-products can be different, which is not limited.

[0092] It is understandable that in an ideal fuel combustion situation, the fuel (mainly hydrocarbons) in the engine fully reacts with oxygen. Take gasoline as an example. The main components of gasoline are various hydrocarbons, such as octane. When the fuel and sufficient air (about 21% of air is oxygen) are in the cylinder of the engine, after the spark plug ignites, the carbon element combines with oxygen to form carbon dioxide, and the hydrogen element combines with oxygen to form water. These two substances are the main products of fuel combustion and are produced in large quantities during normal combustion.

[0093] Also, when the fuel is not completely burned, carbon monoxide and hydrocarbons are produced because: the fuel-air mixture ratio is not appropriate, or the oxygen supply is insufficient during the combustion process, resulting in incomplete combustion of the fuel and the production of carbon monoxide. In addition, the incomplete combustion of the fuel or the part that does not participate in the combustion will appear in the exhaust gas in the form of hydrocarbons.

[0094] Based on the above description, the hybrid vehicle can determine the fuel combustion status of the engine based on the exhaust information. Then, when the fuel combustion status is that the fuel is fully burned, it can be considered that even if the engine has undergone a start-stop process, since the fuel is fully burned, no oil pollution will be generated to pollute the rear oxygen sensor. Based on this, the hybrid vehicle can maintain the same number of start-stop times.

[0095] Otherwise, when the fuel combustion condition is that the fuel is not fully burned, it can be considered that the start-stop process of the engine may produce oil pollution that contaminates the rear oxygen sensor. That is, the possibility of the rear oxygen sensor being contaminated increases. Then, the current start-stop number can be added to the preset value to obtain the updated start-stop number, so that the updated start-stop number is closer to the preset number corresponding to the frequent start-stop condition of the engine.

[0096] For example, if the preset value is 1 and the preset number of times in the above example is 7, if the current start-stop number is 3, when it is determined that the fuel combustion condition is fully burned, it can be considered that the engine start-stop will not produce oil pollution to the rear oxygen sensor. Therefore, the start-stop number can be maintained at 3.

[0097] Otherwise, when it is determined that the fuel combustion condition is that the fuel is not fully burned, it can be considered that the engine start-stop may contaminate the rear oxygen sensor. Therefore, the current start-stop number 3 and the preset value 1 can be added to obtain the updated start-stop number 4. It can be understood that compared with the current start-stop number 3, the updated start-stop number 4 is closer to the preset number 7 corresponding to the frequent start-stop condition of the engine.

[0098] Based on the above-mentioned examples of exhaust information and fuel combustion conditions, as a specific example, a hybrid vehicle may determine that the fuel combustion condition is insufficiently burned when the exhaust temperature is less than or equal to a preset temperature and / or the content of combustion byproducts is greater than a preset content. Otherwise, when the exhaust temperature is greater than a preset temperature and the content of combustion byproducts is less than or equal to a preset content, the fuel combustion condition is determined to be fully burned.

[0099] It should be noted that by combining the exhaust gas temperature and the content of combustion by-products to determine the fuel combustion situation, it is possible to achieve a comprehensive consideration of the fuel combustion situation from different angles. Specifically, the exhaust gas temperature can indirectly reflect whether the fuel is fully burned, while the content of combustion by-products directly reflects whether the fuel is completely converted into the expected products and whether there are excess by-products that are not fully burned. Furthermore, a comprehensive analysis based on the exhaust gas temperature and the content of combustion by-products can more accurately determine whether the fuel is fully burned.

[0100] Moreover, the use of the above-mentioned "and" and "or" logic can make the judgment more rigorous and in line with the actual situation. For example, when determining that the fuel is not fully burned, it can be determined only when the exhaust gas temperature is less than or equal to the preset temperature, or the content of combustion by-products is greater than the preset content. Furthermore, various abnormal conditions that may lead to incomplete combustion can be captured in time. In addition, the fuel is judged to be fully burned only when the exhaust gas temperature is greater than the preset temperature and the content of combustion by-products is less than or equal to the preset content (that is, only when all indicators meet the characteristics of full combustion), which can greatly improve the accuracy of judging the actual situation of fuel combustion.

[0101] In one embodiment, the preset value can be set according to actual conditions, and is not limited thereto. For example, the preset value can be 1. Alternatively, since it can be determined that insufficient combustion of fuel will contaminate the rear oxygen sensor, in order to reduce the contamination degree of the rear oxygen sensor as much as possible to reduce the failure rate, the preset value can also be a value greater than 1.

[0102] Based on the above description, in view of the fact that incomplete combustion of fuel will increase the risk of contamination of the rear oxygen sensor, therefore, when it is determined that the fuel combustion condition is incomplete combustion of fuel, the purpose of increasing the number of starts and stops by a preset value is: in this way, the statistical number of starts and stops can more accurately reflect the actual start-stop working condition of the engine, making it closer to the number corresponding to the frequent start-stop working condition of the engine. That is, compared with the original start-stop number simply counted from the frequency of starting and stopping, the operation of increasing the number of starts and stops by a preset value based on the engine's incomplete fuel combustion can make it possible to more comprehensively consider the fuel combustion condition when subsequently judging whether the engine is in a frequent start-stop working condition. Furthermore, in the subsequent steps, it can be more accurately determined whether it is necessary to switch the operation of the heating voltage control strategy of the rear oxygen sensor to ensure that the rear oxygen sensor can still operate normally under complex working conditions that may have contamination risks.

[0103] Based on the above example, it can be understood that even if the actual number of engine starts and stops in the current driving cycle is greater than the above preset number, since the fuel is fully burned each time it is started and stopped, the hybrid vehicle will not determine that the start-stop condition is a frequent start-stop condition. Based on this, the hybrid vehicle can avoid using the second strategy to adjust the heating voltage of the rear oxygen sensor too early. In addition, the energy consumption required for the rear oxygen sensor to work is reduced while ensuring that the rear oxygen sensor is normal.

[0104] The above examples illustrate various scenarios for determining the start-stop conditions of the engine based on the start-stop information. Based on the above start-stop information, the hybrid vehicle can quickly and accurately determine the start-stop conditions of the engine, providing a basis for switching the heating voltage control strategy based on the start-stop conditions.

[0105] S103: When the start-stop operating condition is a frequent start-stop operating condition, switch the heating voltage control strategy of the rear oxygen sensor from the first strategy to the second strategy.

[0106] Wherein, under the same conditions, the heating voltage of the rear oxygen sensor determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy.

[0107] In one embodiment, the above conditions can be considered to be used to describe the working scenario of the rear oxygen sensor, which can be characterized by preset parameters. Exemplarily, the above preset parameters include but are not limited to the flow rate flowing through the rear oxygen sensor, the exhaust gas temperature, etc., which are not limited to this. That is, under the same conditions (for example, under the same flow rate and exhaust gas temperature) of the rear oxygen sensor, the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy.

[0108] In one embodiment, the first strategy described above can be considered as a strategy corresponding to the normal start-stop condition. In the normal start-stop condition, since the engine fuel is fully burned, no pollution is caused to the rear oxygen sensor, or the number of times the fuel is not fully burned is small, the degree of pollution to the rear oxygen sensor is low.

[0109] Based on this, it can be considered that the rear oxygen sensor can work normally under normal start-stop conditions. Therefore, in order to save energy consumption, the hybrid vehicle can determine and adjust the heating voltage based on the first strategy.

[0110] However, when the start-stop condition is a frequent start-stop condition, based on the above explanation of the frequent start-stop condition, it can be considered that the rear oxygen sensor is heavily contaminated under this condition. In addition, the rear oxygen sensor can decompose and volatilize the exhaust oil attached to the surface at high temperature, reduce the attachment and accumulation of oil, stabilize the performance of the internal sensor element, and enable the rear oxygen sensor to resume function at high temperature.

[0111] Based on this, switching the heating voltage control strategy of the rear oxygen sensor from the first strategy to the second strategy can make the heating voltage determined from the second strategy at least greater than or equal to the heating voltage determined from the first strategy under the same conditions, so that the rear oxygen sensor can recover its function at high temperature and reduce the failure rate of the high-temperature sensor. In addition, determining the heating voltage based on the second strategy can also make the determined heating voltage more reasonable than the subjectively set heating voltage. Furthermore, energy saving can be achieved to the greatest extent on the basis of ensuring that the rear oxygen sensor can recover its function at high temperature.

[0112] The first strategy and the second strategy can both be set in advance, and there is no limitation on this. For example, it can be considered that the first strategy and the second strategy can both be used to describe the corresponding relationship between the exhaust gas temperature and the heating voltage at the rear oxygen sensor. Moreover, the corresponding relationship can include an inversely proportional relationship between the exhaust gas temperature and the heating voltage.

[0113] It is understandable that the higher the exhaust gas temperature, the closer the fuel combustion condition during engine operation is to the condition of full fuel combustion. At this time, the degree of oil pollution to the rear oxygen sensor is usually low, so there is no need to set a large heating voltage to increase the temperature of the rear oxygen sensor. Based on this, the higher the exhaust gas temperature, the smaller the corresponding heating voltage, until there is no need to heat the rear oxygen sensor. That is, until the heating voltage is 0.

[0114] As a specific example, the first strategy may be as shown in Table 1 below, and the second strategy may be as shown in Table 2 below. The details are as follows:

[0115] Table 1:

[0116]

[0117] Table 2:

[0118]

[0119] Among them, based on the above Tables 1 and 2, it can be seen that before 800 degrees Celsius, the heating voltage determined from Table 2 for the rear oxygen sensor under the same working scenario (same exhaust gas temperature) is greater than the heating voltage determined from Table 1. Moreover, in Tables 1 and 2, the higher the exhaust gas temperature, the lower the heating voltage, until the heating voltage is 0.

[0120] However, when the exhaust gas temperature is greater than or equal to 800 degrees Celsius, it can be considered that the temperature in the cylinder of the engine is already high. At this time, the heating voltages determined from Table 1 and Table 2 can be the same until the rear oxygen sensor does not need to be heated based on the heating voltage.

[0121] In another embodiment, at the same exhaust gas temperature, the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature. That is, the higher the exhaust gas temperature, the smaller the voltage difference between the heating voltages determined from Table 2 and Table 1 respectively at the same exhaust gas temperature, until both are 0.

[0122] For example, in Table 2 and Table 1, at 300°C, the corresponding voltage difference is 12.2-11.5=0.7; at 400°C, the corresponding voltage difference is 11.8-11.4=0.4; at 600°C, the corresponding voltage difference is 10.6-10.3=0.3. At 700°C, the corresponding voltage difference is 9-8.8=0.2. And, above 700°C, the voltage difference is 0.

[0123] Based on this, when the exhaust gas temperature is low, it can be considered that the pollution degree of the rear oxygen sensor is serious, so the voltage difference between the heating voltage determined from the second strategy and the heating voltage determined from the first strategy can be larger. In addition, the surface temperature of the rear oxygen sensor can be increased more quickly, and the adhesion and accumulation of oil stains can be better prevented.

[0124] However, when the exhaust gas temperature is high, it can be considered that the pollution degree of the rear oxygen sensor is small. Therefore, on the basis of ensuring that the oil pollution with a small pollution degree can be cleaned, the difference between the heating voltage determined from the second strategy and the heating voltage determined from the first strategy can be reduced to save energy. That is, in the scenario where the exhaust gas temperature is high, although the heating voltage determined from the second strategy is greater than the heating voltage determined from the first strategy, the amplitude of the voltage difference between the two can be reduced.

[0125] Based on the above description, by setting the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy at the same exhaust gas temperature to be inversely proportional to the exhaust gas temperature, the actual heating demand of the rear oxygen sensor at different exhaust gas temperatures can be fully considered to avoid energy waste caused by determining a larger heating voltage from the second strategy when the exhaust gas temperature is high. While ensuring the normal operation of the rear oxygen sensor, the reasonable allocation and efficient use of energy are achieved.

[0126] In one embodiment, the first strategy and the second strategy corresponding to Table 1 and Table 2 are only examples. In another embodiment, the hybrid vehicle can also establish the first strategy and the second strategy based only on flow rate, or based on information such as flow rate and gas temperature. In this embodiment, the specific adjustment method of the heating voltage in the first strategy and the second strategy is not limited.

[0127] S104 : Adjust the heating voltage of the rear oxygen sensor based on the second strategy.

[0128] In one embodiment, the method of adjusting the heating voltage based on the second strategy can be as described in the above example, which is not limited to this. It should be noted that when the start-stop condition is a normal start-stop condition, the hybrid vehicle can maintain the first strategy and adjust the heating voltage based on the first strategy.

[0129] It is understandable that at the beginning of each driving cycle, the engine has not started yet, or has not stopped after starting. At this time, the start-stop condition of the engine will be a normal start-stop condition. Therefore, it can be considered that at the beginning of each driving cycle, the hybrid vehicle determines the heating voltage based on the first strategy. Then, in the current driving cycle, it is determined whether to switch from the first strategy to the second strategy based on the above steps S101-S104, which will not be described in detail.

[0130] Based on the above description, it can be considered that in the last driving cycle, even if the first strategy is switched to the second strategy, the hybrid vehicle can reset the heating voltage control strategy to the first strategy at the beginning of the current driving cycle. Furthermore, at the beginning of each driving cycle, the heating voltage can be adjusted based on the first strategy to save energy.

[0131] Based on the above description, in this embodiment, in the current driving cycle, the start-stop information of the engine when the hybrid vehicle is driving can be obtained to determine the start-stop working condition of the engine based on the start-stop information. When the start-stop working condition is a frequent start-stop working condition, it can be considered that the frequent start-stop of the engine may cause the fuel to be not fully burned, so that the oil produced by the incomplete combustion is attached to the rear oxygen sensor, causing pollution to the rear oxygen sensor. Based on this, in order to protect the rear oxygen sensor, the heating voltage control strategy of the rear oxygen sensor can be switched from the first strategy to the second strategy when the start-stop working condition is a frequent start-stop working condition. Among them, since the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same conditions, when the heating voltage of the rear oxygen sensor is adjusted based on the second strategy, the temperature of the rear oxygen sensor when operating based on the heating voltage will be greater than or equal to the temperature when operating based on the heating voltage determined based on the first strategy. Furthermore, the rear oxygen sensor can be made to decompose and volatilize the exhaust oil attached to the surface based on a higher heating temperature, stabilize the performance of the internal sensor element, and enable the rear oxygen sensor to restore its function at high temperature, thereby reducing the failure rate of the rear oxygen sensor. Furthermore, determining the heating voltage based on the second strategy can also make the determined heating voltage more reasonable than the subjectively set heating voltage. Further, energy saving can be achieved to the greatest extent while ensuring that the rear oxygen sensor can recover its function at high temperature.

[0132] In order to more clearly illustrate the scheme in this application, the scheme in this application is described below using specific embodiments. Figure 2 , Figure 2 This is a flow chart of an implementation method of a rear oxygen sensor control method provided by another embodiment of the present application.

[0133] In the current driving cycle, the hybrid vehicle can obtain the start-stop information of the engine. For example, the start-stop information is the number of engine starts and stops. Afterwards, the vehicle can determine the start-stop condition of the engine based on the start-stop information. For example, when the number of starts and stops is greater than a preset number, the start-stop condition is determined to be a frequent start-stop condition. Otherwise, when the number of starts and stops is less than or equal to the preset number, the start-stop condition is determined to be a normal start-stop condition.

[0134] Finally, when the start-stop condition is a frequent start-stop condition, the heating voltage control strategy of the rear oxygen sensor is switched from the first strategy to the second strategy. That is, the heating voltage of the rear oxygen sensor is adjusted based on the second strategy. Otherwise, when the start-stop condition is a normal start-stop condition, the heating voltage of the rear oxygen sensor is still adjusted based on the first strategy.

[0135] See also Figure 3 , Figure 3 : is a structural block diagram of a control device for a rear oxygen sensor provided in an embodiment of the present application. The control device for the rear oxygen sensor in this embodiment includes modules for executing Figure 1 to Figure 2For details, please refer to the steps in the corresponding embodiment. Figure 1 to Figure 2 as well as Figure 1 to Figure 2 For the convenience of explanation, only the parts related to this embodiment are shown. Figure 3 , the control device 300 of the rear oxygen sensor may include: an acquisition module 310, a determination module 320, a switching module 330 and an adjustment module 340, wherein:

[0136] The acquisition module 310 is used to acquire the start and stop information of the engine when the hybrid vehicle is driving in the current driving cycle.

[0137] The determination module 320 is used to determine the start-stop condition of the engine based on the start-stop information.

[0138] The switching module 330 is used to switch the heating voltage control strategy of the rear oxygen sensor from the first strategy to the second strategy when the start-stop condition is a frequent start-stop condition; under the same working scenario, the heating voltage determined from the second strategy of the rear oxygen sensor is greater than or equal to the heating voltage determined from the first strategy.

[0139] The adjustment module 340 is configured to adjust a heating voltage of the rear oxygen sensor based on a second strategy.

[0140] In one embodiment, the start-stop information includes the number of starts and stops, and the acquisition module 310 is further used to:

[0141] When the engine switches from a start state to a stop state, exhaust gas information at the rear oxygen sensor is obtained; and the number of starts and stops is determined based on the exhaust gas information.

[0142] In one embodiment, the acquisition module 310 is further used to:

[0143] The fuel combustion condition of the engine is determined based on the exhaust gas information; if the fuel combustion condition is that the fuel is fully burned, the start-stop number is maintained unchanged; if the fuel combustion condition is that the fuel is not fully burned, the current start-stop number is added to the preset value to obtain the updated start-stop number.

[0144] In one embodiment, the exhaust gas information includes at least one of the exhaust gas temperature and the content of combustion by-products; in one embodiment, the acquisition module 310 is further used to:

[0145] If the exhaust gas temperature is less than or equal to the preset temperature, and / or the content of the combustion byproducts is greater than the preset content, it is determined that the fuel combustion condition is that the fuel is not fully burned;

[0146] If the exhaust gas temperature is greater than the preset temperature, and the content of combustion by-products is less than or equal to the preset content, it is determined that the fuel combustion condition is complete combustion of the fuel.

[0147] In one embodiment, the start-stop information includes the number of starts and stops, and the determination module 320 is further used to:

[0148] If the number of starts and stops is greater than the preset number, the start-stop condition is determined to be a frequent start-stop condition; if the number of starts and stops is less than or equal to the preset number, the start-stop condition is determined to be a normal start-stop condition.

[0149] In one embodiment, the start-stop information includes the interval between each start and stop of the engine; the determination module 320 is further used to:

[0150] Determine the average duration of multiple intervals; if the average duration is less than or equal to the preset duration, determine that the start-stop condition is a frequent start-stop condition; if the average duration is greater than the preset duration, determine that the start-stop condition is a normal start-stop condition.

[0151] In one embodiment, the control device 300 of the rear oxygen sensor further includes:

[0152] The execution module is used to determine the heating voltage based on the first strategy at the beginning of each driving cycle, and execute the target step and the steps after the target step; the target step includes obtaining the start and stop information of the engine when the hybrid vehicle is driving.

[0153] In one embodiment, the first strategy and the second strategy are respectively used to describe the corresponding relationship between the exhaust gas temperature at the rear oxygen sensor and the heating voltage; wherein, under the same exhaust gas temperature, the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature.

[0154] When it is understood that Figure 3 In the block diagram of the control device of the rear oxygen sensor shown in FIG. 1 , each module is used to execute Figure 1 to Figure 2 The steps in the corresponding embodiments, and for Figure 1 to Figure 2 Each step in the corresponding embodiment has been explained in detail in the above embodiment. Figure 1 to Figure 2 as well as Figure 1 to Figure 2 The relevant descriptions in the corresponding embodiments are not repeated here.

[0155] Figure 4 is a structural block diagram of a vehicle provided by an embodiment of the present application. Figure 4 As shown, the vehicle 400 of this embodiment includes: a processor 410, a memory 420, and a computer program 430 stored in the memory 420 and executable on the processor 410, such as a program of a control method for a rear oxygen sensor. When the processor 410 executes the computer program 430, the steps in each embodiment of the control method for the rear oxygen sensor described above are implemented, such as Figure 1 Alternatively, the processor 410 implements the above when executing the computer program 430 Figure 3 The functions of each module in the corresponding embodiment are, for example, Figure 3 For details on the functions of each module shown, please refer to Figure 3 Related description in the corresponding embodiment.

[0156] Exemplarily, the computer program 430 may be divided into one or more modules, one or more modules are stored in the memory 420, and are executed by the processor 410 to implement the control method of the rear oxygen sensor provided in the embodiment of the present application. One or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 430 in the vehicle 400. For example, the computer program 430 may implement the control method of the rear oxygen sensor provided in the embodiment of the present application.

[0157] The vehicle 400 may include, but is not limited to, a processor 410 and a memory 420. Those skilled in the art will appreciate that Figure 4 This is only an example of vehicle 400 and does not constitute a limitation of vehicle 400 , which may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the vehicle may also include input and output devices, network access devices, buses, etc.

[0158] The processor 410 may be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0159] The memory 420 may be an internal storage unit of the vehicle 400, such as a hard disk or memory of the vehicle 400. The memory 420 may also be an external storage device of the vehicle 400, such as a plug-in hard disk, a smart memory card, a flash memory card, etc. equipped on the vehicle 400. Furthermore, the memory 420 may also include both an internal storage unit of the vehicle 400 and an external storage device.

[0160] An embodiment of the present application provides a computer-readable storage medium, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a control method for a rear oxygen sensor as in the above-mentioned embodiments is implemented.

[0161] An embodiment of the present application provides a computer program product. When the computer program product is run on a vehicle, the vehicle executes the control method of the rear oxygen sensor in the above-mentioned embodiments.

[0162] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A control method for a rear oxygen sensor, characterized in that: The method comprises: In the current driving cycle, the start and stop information of the engine of the hybrid vehicle is obtained; determining a start-stop operating condition of the engine based on the start-stop information; When the start-stop operating condition is a frequent start-stop operating condition, the heating voltage control strategy of the rear oxygen sensor is switched from the first strategy to the second strategy; under the same working scenario, the heating voltage determined by the second strategy of the rear oxygen sensor is greater than or equal to the heating voltage determined by the first strategy; A heater voltage of the rear oxygen sensor is adjusted based on the second strategy.

2. The method according to claim 1, characterized in that The start-stop information includes the number of starts and stops; the step of obtaining the start-stop information of the engine when the hybrid vehicle is running includes: When the engine is switched from a start state to a stop state, obtaining exhaust gas information at the rear oxygen sensor; The start-stop number is determined based on the exhaust gas information.

3. The method according to claim 2, characterized in that The determining the start-stop number based on the exhaust gas information includes: determining fuel combustion conditions of the engine based on the exhaust gas information; If the fuel combustion condition is that the fuel is fully burned, the start-stop times are maintained unchanged; If the fuel combustion condition is that the fuel is not fully burned, the current start-stop number is added to the preset value to obtain the updated start-stop number.

4. The method according to claim 3, characterized in that: The exhaust gas information includes at least one of the exhaust gas temperature and the content of combustion byproducts; and determining the fuel combustion condition of the engine based on the exhaust gas information includes: If the exhaust gas temperature is less than or equal to a preset temperature, and / or the content of the combustion byproducts is greater than a preset content, it is determined that the fuel combustion condition is that the fuel is not fully burned; If the exhaust gas temperature is greater than the preset temperature, and the content of the combustion by-products is less than or equal to the preset content, it is determined that the fuel combustion condition is complete combustion of the fuel.

5. The method according to any one of claims 1 to 4, characterized in that: The start-stop information includes the number of starts and stops; and determining the start-stop operating condition of the engine based on the start-stop information includes: If the start-stop number is greater than a preset number, determining that the start-stop operating condition is a frequent start-stop operating condition; If the start-stop number is less than or equal to the preset number, it is determined that the start-stop condition is a normal start-stop condition.

6. The method according to claim 1, characterized in that The start-stop information includes the interval between each start and stop of the engine; The determining the start-stop operating condition of the engine based on the start-stop information further includes: Determine an average duration of multiple intervals; If the average duration is less than or equal to the preset duration, determining that the start-stop operating condition is a frequent start-stop operating condition; If the average duration is greater than the preset duration, it is determined that the start-stop operating condition is a normal start-stop operating condition.

7. The method according to any one of claims 1 to 4 or 6, characterized in that: The method further comprises: At the beginning of each driving cycle, the heating voltage is determined based on the first strategy, and a target step and steps after the target step are executed; the target step includes obtaining start and stop information of the engine when the hybrid vehicle is driving.

8. The method according to any one of claims 1 to 4 or 6, characterized in that: The first strategy and the second strategy are respectively used to describe the corresponding relationship between the exhaust gas temperature at the rear oxygen sensor and the heating voltage; wherein, at the same exhaust gas temperature, the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature.

9. A vehicle, characterized in that: The vehicle comprises a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the vehicle implements the method according to any one of claims 1 to 8.

10. A computer program product, characterized in that The invention comprises a computer program, which, when being executed, enables the method according to any one of claims 1 to 8 to be performed.

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