Engine emission control method, device and vehicle

Abstract

The present application discloses an engine emission control method, device and vehicle, which relate to the field of engine after-treatment. The method identifies the efficiency instability state of a three-way catalytic converter based on the monitoring value of a first characteristic parameter of the engine after-treatment. When it is identified that the three-way catalytic converter is in an efficiency instability state, an efficiency risk value characterizing the degree of instability of the efficiency instability state is determined based on the monitoring value of a second characteristic parameter. The temperature of the three-way catalytic converter is adjusted in a targeted manner according to a thermal management adjustment strategy corresponding to the efficiency risk value, and / or the fuel supply of the engine is adjusted according to a fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to an efficiency stable state and maintain the conversion efficiency in the efficiency stable state. When it is detected that the three-way catalytic converter is in an efficiency unstable state, corresponding measures can be taken to adjust the three-way catalytic converter based on the degree of instability, thereby effectively improving the robustness of the conversion rate and reducing emission risks.

Description

Technical Field

[0001] The present application relates to the technical field of engine aftertreatment, and in particular to an engine emission control method, device and vehicle. Background Art

[0002] The TWC (Three-Way Catalytic Converter) is a core component in vehicle exhaust purification systems. It primarily processes harmful gases such as carbon monoxide, hydrocarbons, and nitrogen oxides emitted by the engine, converting them into carbon dioxide, water, and nitrogen. This not only reduces harmful vehicle emissions but also air pollution, significantly impacting environmental protection. The conversion efficiency of the TWC directly impacts whether a vehicle's exhaust emissions meet standards. Maintaining this efficiency within an ideal range to minimize the risk of excessive engine exhaust emissions has become a pressing issue. Summary of the Invention

[0003] In view of the above problems, this application provides an engine emission control method, device and vehicle to achieve the purpose of reducing the risk of excessive emissions and improving conversion stability. The specific solution is as follows:

[0004] A first aspect of the present application provides an engine emission control method, comprising:

[0005] Identifying an unstable efficiency state of a three-way catalytic converter based on a monitored value of a first characteristic parameter of an engine aftertreatment;

[0006] When it is identified that the three-way catalytic converter is in the efficiency unstable state, determining an efficiency risk value representing the degree of instability of the efficiency unstable state according to the monitored value of the second characteristic parameter;

[0007] The temperature of the three-way catalytic converter is adjusted according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or the fuel supply of the engine is adjusted according to the fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to the efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

[0008] In one possible implementation, identifying the unstable efficiency state of the three-way catalytic converter based on the monitored value of the first characteristic parameter of the engine aftertreatment includes:

[0009] determining whether there is fluctuation in conversion efficiency of the three-way catalytic converter based on first statistical data of the monitored value of the first characteristic parameter within a first monitoring period;

[0010] When it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, it is determined whether the three-way catalytic converter is in an efficiency unstable state according to second statistical data representing the continuous fluctuation of the conversion efficiency during a second monitoring period.

[0011] In one possible implementation, the first characteristic parameter includes a monitoring signal of a rear oxygen sensor, and the first statistical data includes a signal mean value of the monitoring signal, a signal oscillation amplitude when oscillation occurs, and a number of signal oscillations. Determining whether there is fluctuation in the conversion efficiency of the three-way catalytic converter based on the first statistical data of the monitoring value of the first characteristic parameter within a first monitoring period includes:

[0012] If the signal mean is greater than a first threshold, the signal oscillation amplitude is greater than a second threshold, and the number of signal oscillations is greater than a third threshold, it is determined that the conversion efficiency of the three-way catalytic converter fluctuates.

[0013] In one possible implementation, the second statistical data includes: duration of fluctuation, number of oscillations, and continuous engine work. When it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, determining whether the three-way catalytic converter is in an efficiency unstable state based on the second statistical data representing the continuous fluctuation of the conversion efficiency during the second monitoring period includes:

[0014] If the duration of the fluctuation is greater than the fourth threshold, or the number of oscillations is greater than the fifth threshold, or the continuous work done by the engine is greater than the sixth threshold, it is determined that the three-way catalytic converter is in an efficiency unstable state.

[0015] In one possible implementation, the second characteristic parameter includes: a post-processing temperature and an oscillation parameter characterizing the severity of oscillation of a monitoring signal of a rear oxygen sensor. When identifying that the three-way catalytic converter is in the efficiency unstable state, determining an efficiency risk value characterizing the degree of instability of the efficiency unstable state based on the monitored value of the second characteristic parameter includes:

[0016] The efficiency risk value is determined according to the temperature interval in which the temperature value of the post-processing temperature lies and the oscillation degree interval in which the parameter value of the oscillation parameter lies.

[0017] In one possible implementation, adjusting the temperature of the three-way catalytic converter according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjusting the fuel supply of the engine according to the fuel injection strategy corresponding to the efficiency risk value, includes:

[0018] According to the current operating condition of the engine, the temperature of the three-way catalytic converter is adjusted by adopting an exhaust temperature management strategy after reverse power or an exhaust temperature management strategy during positive power;

[0019] When the temperature of the three-way catalytic converter does not reach the target temperature after adjustment, the fuel supply of the engine is adjusted according to the fuel injection strategy, and the reference value calibration table is updated according to the fuel injection amount that reaches the target temperature.

[0020] In a possible implementation, before identifying the unstable efficiency state of the three-way catalytic converter based on the monitored value of the first characteristic parameter of the engine aftertreatment, the method further includes:

[0021] Whether to perform an operation of identifying an unstable efficiency state of the three-way catalytic converter is determined according to the operating parameters of the engine and the working state of the oxygen sensor.

[0022] In one possible implementation, determining whether to perform an operation of identifying an unstable efficiency state of the three-way catalytic converter based on operating parameters of the engine and an operating state of the oxygen sensor includes:

[0023] If both the front oxygen sensor and the rear oxygen sensor are in the ready state, and the water temperature of the engine is greater than the water temperature threshold, the temperature of the three-way catalytic converter is within the temperature range, the engine speed is within the speed range, and the engine load rate is within the load rate range, then it is determined to perform an identification operation of the unstable efficiency state of the three-way catalytic converter.

[0024] A second aspect of the present application provides an engine emission control device, comprising:

[0025] a state recognition module, configured to recognize an efficiency instability state of the three-way catalytic converter based on a monitoring value of a first characteristic parameter of the engine post-processing;

[0026] a risk determination module, configured to, when identifying that the three-way catalytic converter is in the efficiency unstable state, determine an efficiency risk value representing a degree of instability of the efficiency unstable state based on a monitored value of a second characteristic parameter; and

[0027] an emission adjustment module, configured to adjust the temperature of the three-way catalytic converter according to a thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjust the fuel supply to the engine according to a fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to a stable efficiency state and maintain the conversion efficiency in the stable efficiency state.

[0028] A third aspect of the present application provides a vehicle, comprising a vehicle body and an electronic device disposed in the vehicle body, wherein the electronic device comprises at least one processor and a memory connected to the processor, wherein:

[0029] The memory is used to store computer programs;

[0030] The processor is used to execute the computer program so that the electronic device can implement the engine emission control method as described in the first aspect or any implementation of the first aspect.

[0031] The fourth aspect of the present application provides a computer program product, comprising computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the engine emission control method of the first aspect or any implementation of the first aspect.

[0032] In a fifth aspect, the present application provides a computer storage medium, which carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the engine emission control method of the first aspect or any implementation of the first aspect.

[0033] By virtue of the above technical solution, the engine emission control method provided by the present application identifies the efficiency instability state of the three-way catalytic converter based on the monitored value of the first characteristic parameter of the engine aftertreatment. When the three-way catalytic converter is identified as being in an efficiency instability state, an efficiency risk value representing the degree of instability of the efficiency instability state is determined based on the monitored value of the second characteristic parameter. The temperature of the three-way catalytic converter is specifically adjusted according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or the fuel supply to the engine is adjusted according to the fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to an efficiency stable state and maintain the conversion efficiency in the efficiency stable state. When the engine emission control method detects that the three-way catalytic converter is in an efficiency instability state, it can take appropriate measures based on the degree of instability to maintain the conversion rate of the three-way catalytic converter at an ideal level, effectively improving the robustness of the three-way catalytic converter conversion rate and reducing emission risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0035] Figure 1 A flow chart of an engine emission control method provided in this application;

[0036] Figure 2 A schematic diagram of an efficiency risk value provided for this application;

[0037] Figure 3 An architectural diagram of an engine after-treatment system provided in this application;

[0038] Figure 4 A structural diagram of an engine emission control device provided in this application;

[0039] Figure 5 This is a structural diagram of an electronic device provided in this application. DETAILED DESCRIPTION

[0040] The following describes the embodiments of the present application in conjunction with the accompanying drawings. The terms used in the implementation methods of the present application are only used to explain the specific embodiments of the present application and are not intended to limit the present application.

[0041] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0042] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, and this is merely a way of distinguishing the objects of the same attributes when describing them in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0043] The role of the three-way catalytic converter in the engine aftertreatment system is primarily reflected in its high conversion efficiency. The three-way catalytic converter can convert the main pollutants in automobile exhaust, CO, HC, and NOx, into harmless carbon dioxide, water, and nitrogen, thereby significantly reducing pollution to the environment. Among them, "enrichment and leanness" in the three-way catalytic converter refers to a special fuel injection strategy used to optimize the performance of the three-way catalytic converter and extend its service life. This strategy adjusts the fuel injection amount under different engine operating conditions, forming alternating rich and lean mixtures inside the three-way catalytic converter, thereby optimizing the catalytic reaction process. It is directly related to its oxygen storage capacity, which is mainly reflected in its processing limit under extreme air-fuel ratio conditions. Too rich or too lean a mixture has a significant impact on the conversion efficiency of the three-way catalytic converter.

[0044] Currently, to maintain the conversion efficiency of three-way catalytic converters, closed-loop control based on rear oxygen sensors, front oxygen sensors, or a combination of both can be used to adjust the conversion rate of the three-way catalytic converter by adjusting the fuel dilution and adding burners to adjust thermal management. These control methods are relatively simple and the results are not ideal. They cannot achieve targeted adjustments to the reduced conversion efficiency of the three-way catalytic converter.

[0045] In order to solve the above problems, an embodiment of the present application provides an engine emission control method. The engine emission control method of the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0046] Reference Figure 1 , Figure 1 The process diagram of an engine emission control method provided in an embodiment of the present application is as follows: Figure 1 As shown, an engine emissions control method provided in an embodiment of the present application can be applied to an electronic control unit of an engine aftertreatment system. The engine here can be a fuel engine, such as a gas engine (natural gas engine, etc.) or a fuel engine (petrol engine, etc.). The engine emissions control method can include steps 101 to 103, each of which is described in detail below.

[0047] 101. Identify an unstable efficiency state of a three-way catalytic converter based on a monitored value of a first characteristic parameter of an engine aftertreatment process.

[0048] Specifically, refer to Figure 3 The diagram shows the structure of an engine aftertreatment system, primarily consisting of a supercharger, a front oxygen sensor, a wastegate valve, a TWC with wastegate, a rear oxygen sensor, and an ECU (electronic control unit). The rear oxygen sensor is installed after the three-way catalytic converter (TCC). Its primary function is to detect the oxygen content in the exhaust gas after purification by the TC. By comparing the data from the front and rear oxygen sensors, it is possible to determine whether the TC is functioning properly. When the TC is operating at a stable conversion efficiency, the oxygen monitoring value from the rear oxygen sensor should also be stable. Conversely, fluctuations in the monitoring value from the rear oxygen sensor indicate an abnormal operating state of the TC, resulting in reduced conversion efficiency. The first characteristic parameter here can be the monitoring signal from the rear oxygen sensor. By observing this monitoring value, it is possible to identify whether the TC is experiencing unstable conversion efficiency.

[0049] 102. When it is identified that the three-way catalytic converter is in an efficiency unstable state, an efficiency risk value characterizing the degree of instability of the efficiency unstable state is determined based on the monitored value of the second characteristic parameter.

[0050] Specifically, when a three-way catalytic converter is identified as experiencing unstable conversion efficiency, the degree of instability, specifically the fluctuation of the rear oxygen sensor signal, can be assessed using a second characteristic parameter to facilitate subsequent targeted adjustments to the unstable state. To facilitate targeted adjustments, this degree of instability can be characterized by an efficiency risk value. This efficiency risk value can be derived from the process temperature and a parameter representing the degree of oscillation of the rear oxygen sensor signal, such as the standard deviation. The degree of instability in the three-way catalytic converter's conversion efficiency can then be determined based on the range within which these parameter values ​​fall.

[0051] 103. Adjust the temperature of the three-way catalytic converter according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjust the fuel supply of the engine according to the fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to the efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

[0052] Based on the efficiency risk value determined, appropriate adjustment measures are taken based on the efficiency risk value. For example, targeted adjustments can be made based on the parameter values ​​identified as being at risk within the efficiency risk value. For example, if the process temperature value is at risk, the temperature of the three-way catalytic converter can be adjusted based on the engine's current operating conditions using either a post-reverse exhaust temperature management strategy or a post-positive exhaust temperature management strategy. If the oscillation parameter value is at risk, the engine's fuel supply can be adjusted based on the fuel injection strategy (i.e., enriching or diluting the engine's fuel supply). If both of these parameters are at risk, the temperature of the three-way catalytic converter can be adjusted based on the engine's current operating conditions using either a post-reverse exhaust temperature management strategy or a post-positive exhaust temperature management strategy. If the adjusted three-way catalytic converter temperature does not reach the target temperature, the engine's fuel supply can be adjusted based on the fuel injection strategy.

[0053] Exhaust temperature management after reverse towing refers to the management of the aftertreatment system temperature while the engine is in reverse towing mode. This typically occurs when the vehicle is decelerating or going downhill, when the engine is in reverse drive. While the engine is not generating power, it still needs to maintain the temperature of the three-way catalytic converter. For example, during reverse towing, the wastegate valve can be opened to divert some exhaust gas from the three-way catalytic converter, maintaining the desired temperature.

[0054] Exhaust temperature management during normal engine operation refers to the management of the aftertreatment system temperature during normal engine operation. During normal engine operation, the engine generates significant heat. Exhaust temperature management during normal engine operation ensures the aftertreatment system operates within the optimal temperature range by optimizing the combustion process and exhaust treatment strategies. For example, this can be achieved by adjusting fuel injection and ignition timing (e.g., retarding the engine ignition angle) to increase the temperature.

[0055] The fuel injection strategy is to enrich or dilute the engine fuel injection so that the conversion efficiency of the three-way catalytic converter remains stable and maintained at the ideal conversion efficiency value.

[0056] It is understandable that those skilled in the art may adjust and select the content of the above-mentioned adjustment measures as needed, which will not be elaborated here.

[0057] This engine emissions control method identifies and categorizes risks based on key characteristic parameters of the engine aftertreatment system. It also triggers corresponding measures based on the risk assessment status, with different risk levels corresponding to different measures. Simultaneous adaptive adjustments can compensate for efficiency deviations caused by factors such as ambient temperature, engine control, and aftertreatment efficiency consistency, effectively improving the robustness of TWC efficiency and reducing emissions control risks.

[0058] In one embodiment, to accurately identify the unstable state of conversion efficiency of the three-way catalytic converter, step 101 of identifying the unstable state of efficiency of the three-way catalytic converter based on the monitored value of the first characteristic parameter of the engine aftertreatment may specifically include:

[0059] Step 11: Determine whether there is fluctuation in the conversion efficiency of the three-way catalytic converter based on first statistical data of the monitored value of the first characteristic parameter within the first monitoring time period.

[0060] In one embodiment, the first characteristic parameter may include a monitoring signal from a rear oxygen sensor, and the first statistical data may include a mean value of the monitoring signal, an amplitude of the signal when oscillation occurs, and the number of signal oscillations. If the mean value is greater than a first threshold, the amplitude of the signal oscillation is greater than a second threshold, and the number of signal oscillations is greater than a third threshold, then it is determined that the conversion efficiency of the three-way catalytic converter is fluctuating. The amplitude of the signal oscillation is the difference between two adjacent amplitudes of the rear oxygen sensor signal when oscillation occurs.

[0061] For example, during the continuous monitoring of the signal of the rear oxygen sensor, if the signal average is >0.2, the oscillation amplitude is >0.2, and the number of oscillations is >2 times within a monitoring period of 2 seconds, it can be determined that the conversion efficiency of the three-way catalytic converter has fluctuated and may be in an unstable state.

[0062] Step 12: When it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, determine whether the three-way catalytic converter is in an efficiency unstable state based on second statistical data representing continuous fluctuations in the conversion efficiency during the second monitoring period.

[0063] In one embodiment, the above-mentioned second statistical data may include: the duration of the fluctuation, the number of oscillations and the continuous work done by the engine. If the duration of the fluctuation is greater than the fourth threshold, or the number of oscillations is greater than the fifth threshold, or the continuous work done by the engine is greater than the sixth threshold, it is determined that the three-way catalytic converter is in an unstable efficiency state.

[0064] For example, when the fluctuation duration is greater than 16 seconds, or the number of oscillations is greater than 8 times, or the engine's continuous work volume is greater than w0, that is, when any of the above conditions is met, it means that the continuous fluctuation of the conversion efficiency of the three-way catalytic converter has made the conversion efficiency of the three-way catalytic converter unstable.

[0065] It is understandable that the above thresholds can be adjusted as appropriate according to different engine signals, and no limitation is imposed here.

[0066] In some embodiments, to better characterize the degree of instability of the conversion efficiency of the three-way catalytic converter and facilitate subsequent selection of adjustment measures, the second characteristic parameter includes: the post-processing temperature and an oscillation parameter characterizing the severity of the oscillation of the monitoring signal of the rear oxygen sensor. Step 102, upon identifying that the three-way catalytic converter is in an efficiency unstable state, determines an efficiency risk value characterizing the degree of instability of the efficiency unstable state based on the monitored value of the second characteristic parameter, which may specifically include:

[0067] The efficiency risk value is determined according to the temperature range in which the temperature value of the post-processing temperature lies and the oscillation degree range in which the parameter value of the oscillation parameter lies.

[0068] Specifically, the oscillation parameter here can be the oscillation standard deviation obtained by statistically processing the post-oxygen sensor signal. The post-processing temperature can be divided into three intervals, such as: 200 < temperature ≤ t0, t0 < temperature ≤ t1, and t1 < temperature ≤ t2. The oscillation standard deviation is divided into three levels: st1 (0.1), st2 (0.2), and st3 (0.3), where the values ​​in parentheses are the corresponding standard deviations.

[0069] Reference Figure 2As shown, the intensity of the adjustment obtained according to the divided intervals is represented, where the horizontal axis is the temperature of the three-way catalytic converter (also known as the post-treatment temperature), and the vertical axis represents the corresponding oscillation standard deviation. It can be seen that the nine areas formed by the interweaving, among which, as the oscillation standard deviation increases from bottom to top, it indicates that the instability of the three-way catalytic converter gradually increases, and the intensity of the adjustment of the engine fuel injection amount based on the signal of the rear oxygen sensor gradually increases. Similarly, from left to right, the intensity of the engine power thermal management needs to be gradually increased. It can be seen that the nine areas can correspond to different adjustment intensities. When making adjustments, the corresponding relationship between the area and the adjustment intensity can be determined based on the corresponding adjustment amplitude and intensity information, and targeted adjustments can be made.

[0070] The reference value calibration table is updated according to the adjusted post-processing temperature and the fuel injection amount that reaches the target temperature, so that it is convenient to directly call it the next time the adjustment is made, thereby improving the timeliness of the adjustment.

[0071] In other embodiments, considering that determination of an unstable state is not necessary in all cases, in order to improve the accuracy and reliability of identifying the unstable state of the efficiency of the three-way catalytic converter, before identifying the unstable state of the efficiency of the three-way catalytic converter in step 101 based on the monitored value of the first characteristic parameter of the engine aftertreatment, the following steps may be specifically performed:

[0072] According to the operating parameters of the engine and the working state of the oxygen sensor, it is determined whether to perform the identification operation of the unstable efficiency state of the three-way catalytic converter.

[0073] Specifically, when both the front oxygen sensor and the rear oxygen sensor are in the ready state, the water temperature of the engine is greater than the water temperature threshold, the temperature of the three-way catalytic converter is within the temperature range, the engine speed is within the speed range, and the engine load rate is within the load rate range, then it is determined to perform the identification operation of the unstable efficiency state of the three-way catalytic converter.

[0074] For example, in a natural gas engine, if the front and rear oxygen sensors are in working order, the engine is in a warm-up state (water temperature > 70°C), 200°C < TWC temperature < 450°C, 700 rpm < engine speed < 1900 rpm, and 10% < engine load < 100%, then the subsequent three-way catalytic converter conversion efficiency unstable state identification operation can be performed. Otherwise, the subsequent identification operation is not performed.

[0075] It should be noted that those skilled in the art may adjust and select the number of the above conditions and the values ​​in the conditions according to different engine types, which will not be elaborated here.

[0076] An engine emission control method provided by an embodiment of the present application is introduced above. The following will introduce a device for executing the above engine emission control method.

[0077] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of an engine emission control device provided in an embodiment of the present application. Figure 4 As shown, the engine emission control device includes:

[0078] A state identification module 401 is used to identify an efficiency unstable state of the three-way catalytic converter based on a monitoring value of a first characteristic parameter of the engine post-processing;

[0079] a risk determination module 402 for determining, when identifying that the three-way catalytic converter is in an efficiency unstable state, an efficiency risk value representing the degree of instability of the efficiency unstable state based on the monitored value of the second characteristic parameter; and

[0080] The emission adjustment module 403 is used to adjust the temperature of the three-way catalytic converter according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjust the fuel supply of the engine according to the fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to the efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

[0081] In one possible implementation, the state identification module 401 identifies the unstable efficiency state of the three-way catalytic converter based on the monitored value of the first characteristic parameter of the engine aftertreatment, including:

[0082] determining whether there is fluctuation in conversion efficiency of the three-way catalytic converter based on first statistical data of a monitored value of a first characteristic parameter within a first monitoring period;

[0083] When it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, it is determined whether the three-way catalytic converter is in an efficiency unstable state according to second statistical data representing continuous fluctuations in the conversion efficiency during the second monitoring period.

[0084] In one possible implementation, the first characteristic parameter includes a monitoring signal of a rear oxygen sensor, and the first statistical data includes a signal mean of the monitoring signal, a signal oscillation amplitude when oscillation occurs, and a number of signal oscillations. The state identification module 401 determines whether the conversion efficiency of the three-way catalytic converter fluctuates based on the first statistical data of the monitoring value of the first characteristic parameter within the first monitoring period, including:

[0085] If the signal mean is greater than the first threshold, the signal oscillation amplitude is greater than the second threshold, and the number of signal oscillations is greater than the third threshold, it is determined that the conversion efficiency of the three-way catalytic converter fluctuates.

[0086] In one possible implementation, the second statistical data includes: duration of fluctuation, number of oscillations, and continuous engine work. When it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, the state identification module 401 determines whether the three-way catalytic converter is in an unstable efficiency state based on the second statistical data representing the continuous fluctuation of the conversion efficiency during the second monitoring period, including:

[0087] If the duration of the fluctuation is greater than the fourth threshold, or the number of oscillations is greater than the fifth threshold, or the continuous work done by the engine is greater than the sixth threshold, it is determined that the three-way catalytic converter is in an unstable efficiency state.

[0088] In one possible implementation, the second characteristic parameter includes: an aftertreatment temperature and an oscillation parameter characterizing the severity of oscillation of a monitoring signal of a rear oxygen sensor. When the risk determination module 402 identifies that the three-way catalytic converter is in an efficiency unstable state, the process of determining an efficiency risk value characterizing the degree of instability of the efficiency unstable state based on the monitored value of the second characteristic parameter includes:

[0089] The efficiency risk value is determined according to the temperature range in which the temperature value of the post-processing temperature lies and the oscillation degree range in which the parameter value of the oscillation parameter lies.

[0090] In one possible implementation, the process in which the emission adjustment module 403 adjusts the temperature of the three-way catalytic converter according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjusts the fuel supply of the engine according to the fuel injection strategy corresponding to the efficiency risk value, includes:

[0091] According to the current operating conditions of the engine, the exhaust temperature management strategy after reverse mopping or the exhaust temperature management strategy during positive power is adopted to adjust the temperature of the three-way catalytic converter;

[0092] When the temperature of the three-way catalytic converter does not reach the target temperature after adjustment, the fuel supply to the engine is adjusted according to the fuel injection strategy, and the reference value calibration table is updated according to the fuel injection amount that reaches the target temperature.

[0093] In a possible implementation, the system further includes: a monitoring enabling module configured to, before identifying an efficiency instability state of the three-way catalytic converter based on a monitoring value of a first characteristic parameter of the engine post-processing:

[0094] According to the operating parameters of the engine and the working state of the oxygen sensor, it is determined whether to perform the identification operation of the unstable efficiency state of the three-way catalytic converter.

[0095] In one possible implementation, the monitoring enabling module determines whether to perform an operation to identify an unstable efficiency state of the three-way catalytic converter based on engine operating parameters and an operating state of the oxygen sensor, including:

[0096] If both the front oxygen sensor and the rear oxygen sensor are in the ready state, the engine water temperature is greater than the water temperature threshold, the temperature of the three-way catalytic converter is within the temperature range, the engine speed is within the speed range, and the engine load rate is within the load rate range, then it is determined to perform the identification operation of the unstable efficiency state of the three-way catalytic converter.

[0097] An electronic device is also provided in an embodiment of the present application. Figure 5 , which shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiments of the present application. The electronic devices in the embodiments of the present application may include, but are not limited to, ECUs (Electronic Control Units), VCUs (Vehicle Control Units), MCUs (Micro Controller Units), and HCUs (Hybrid Control Units). Figure 5 The electronic device shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0098] like Figure 5 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes based on programs stored in a read-only memory (ROM) 502 or programs loaded from a storage device 508 into a random access memory (RAM) 503. When the electronic device is powered on, the RAM 503 also stores various programs and data required for the operation of the electronic device. The processing device 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0099] Typically, the following devices may be connected to the I / O interface 505: an input device 506 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 507 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 508 including, for example, a memory card, a hard disk, etc.; and a communication device 509. The communication device 509 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Figure 5 The electronic device is shown with various devices, but it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed instead.

[0100] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any one of the engine emission control methods provided in the embodiments of the present application.

[0101] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any engine emission control method provided in the embodiment of the present application.

[0102] An embodiment of the present application further provides a vehicle, comprising: a vehicle body and the electronic device as described in the above embodiment arranged in the vehicle body.

[0103] It should also be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided in this application, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines.

[0104] Through the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course can also be implemented by special hardware including application-specific integrated circuits, special CPUs, special memories, special components, etc. In general, all functions performed by computer programs can be easily implemented with corresponding hardware, and the specific hardware structures used to implement the same function can also be diverse, such as analog circuits, digital circuits or special circuits, etc. However, for the present application, software program implementation is a better implementation method in most cases. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer's floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk or optical disk, etc., and includes a number of instructions to enable a computer device (which can be a personal computer, training equipment, or network equipment, etc.) to execute the methods described in each embodiment of the present application.

[0105] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0106] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, a computer, a training device or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website, a computer, a training device or a data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

Claims

1. An engine emission control method, characterized in that: include: determining whether the conversion efficiency of the three-way catalytic converter fluctuates based on a signal average value, a signal oscillation amplitude when oscillation occurs, and a number of signal oscillations of a monitoring signal of the rear oxygen sensor within a first monitoring time period, wherein if the signal average value is greater than a first threshold value, the signal oscillation amplitude is greater than a second threshold value, and the number of signal oscillations is greater than a third threshold value, then it is determined that the conversion efficiency of the three-way catalytic converter fluctuates; When it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, determining whether the three-way catalytic converter is in an efficiency unstable state based on a duration of the fluctuation, a number of oscillations, and a continuous amount of work done by the engine within a second monitoring time period, wherein if the duration of the fluctuation is greater than a fourth threshold, or the number of oscillations is greater than a fifth threshold, or the continuous amount of work done by the engine is greater than a sixth threshold, then it is determined that the three-way catalytic converter is in an efficiency unstable state; When it is identified that the three-way catalytic converter is in the efficiency unstable state, determining an efficiency risk value representing the degree of instability of the efficiency unstable state based on a temperature range within which a post-processing temperature value lies and an oscillation degree range within which a parameter value of an oscillation parameter lies, wherein the oscillation parameter represents the severity of oscillation of a monitoring signal of a rear oxygen sensor; The temperature of the three-way catalytic converter is adjusted according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or the fuel supply of the engine is adjusted according to the fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to the efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

2. The engine emission control method according to claim 1, characterized in that: The adjusting the temperature of the three-way catalytic converter according to the thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjusting the fuel supply of the engine according to the fuel injection strategy corresponding to the efficiency risk value, includes: According to the current operating condition of the engine, the temperature of the three-way catalytic converter is adjusted by adopting an exhaust temperature management strategy after reverse power or an exhaust temperature management strategy during positive power; When the temperature of the three-way catalytic converter does not reach the target temperature after adjustment, the fuel supply of the engine is adjusted according to the fuel injection strategy, and the reference value calibration table is updated according to the fuel injection amount that reaches the target temperature.

3. The engine emission control method according to claim 1, characterized in that: Before determining whether the conversion efficiency of the three-way catalytic converter fluctuates based on the signal mean value, the signal oscillation amplitude, and the number of signal oscillations of the monitoring signal of the rear oxygen sensor within the first monitoring time period, the method further includes: Whether to perform an operation of identifying an unstable efficiency state of the three-way catalytic converter is determined according to the operating parameters of the engine and the working state of the oxygen sensor.

4. The engine emission control method according to claim 3, characterized in that: The determining whether to perform the operation of identifying the unstable efficiency state of the three-way catalytic converter according to the operating parameters of the engine and the working state of the oxygen sensor includes: If both the front oxygen sensor and the rear oxygen sensor are in the ready state, and the water temperature of the engine is greater than the water temperature threshold, the temperature of the three-way catalytic converter is within the temperature range, the engine speed is within the speed range, and the engine load rate is within the load rate range, then it is determined to perform an identification operation of the unstable efficiency state of the three-way catalytic converter.

5. An engine emission control device, characterized in that: include: a state identification module for determining whether the conversion efficiency of the three-way catalytic converter fluctuates based on a signal mean value of a monitoring signal of the rear oxygen sensor within a first monitoring time period, a signal oscillation amplitude when oscillation occurs, and a number of signal oscillations, wherein if the signal mean value is greater than a first threshold value, the signal oscillation amplitude is greater than a second threshold value, and the number of signal oscillations is greater than a third threshold value, then it is determined that the conversion efficiency of the three-way catalytic converter fluctuates; when it is determined that the conversion efficiency of the three-way catalytic converter fluctuates, determining whether the three-way catalytic converter is in an efficiency unstable state based on a duration of the fluctuation, a number of oscillations, and a continuous amount of work done by the engine within a second monitoring time period, wherein if the duration of the fluctuation is greater than a fourth threshold value, or the number of oscillations is greater than a fifth threshold value, or the continuous amount of work done by the engine is greater than a sixth threshold value, then it is determined that the three-way catalytic converter is in an efficiency unstable state; a risk determination module for, when identifying that the three-way catalytic converter is in the efficiency unstable state, determining an efficiency risk value representing the degree of instability of the efficiency unstable state based on a temperature range within which a post-processing temperature value lies and an oscillation degree range within which a parameter value of an oscillation parameter lies, wherein the oscillation parameter represents the severity of oscillation of a monitoring signal of a rear oxygen sensor; and an emission adjustment module, configured to adjust the temperature of the three-way catalytic converter according to a thermal management adjustment strategy corresponding to the efficiency risk value, and / or adjust the fuel supply to the engine according to a fuel injection strategy corresponding to the efficiency risk value, so as to restore the three-way catalytic converter to a stable efficiency state and maintain the conversion efficiency in the stable efficiency state.

6. A vehicle, characterized in that: The invention comprises a vehicle body and an electronic device arranged in the vehicle body, wherein the electronic device comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is configured to execute the computer program so as to enable the electronic device to implement the engine emission control method according to any one of claims 1 to 4.

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