Engine emission control method and device and vehicle

Abstract

The invention discloses an engine emission control method, an engine emission control device and a vehicle, relates to the field of engine post-processing, and recognizes an efficiency unstable state of a three-way catalyst according to a monitoring value of a first characteristic parameter of engine post-processing. And when it is identified that the three-way catalyst is in the efficiency unstable state, determining an efficiency risk value representing the instability degree of the efficiency unstable state according to the monitoring value of the second characteristic parameter. And the temperature of the three-way catalytic converter is adjusted in a targeted mode according to the heat management adjusting strategy corresponding to the efficiency risk value, and / or fuel supply of the engine is adjusted according to the fuel injection strategy corresponding to the efficiency risk value, so that the three-way catalytic converter is restored to the stable efficiency state, and the conversion efficiency in the stable efficiency state is maintained. By means of the method, when it is detected that the efficiency of the three-way catalyst is unstable, corresponding measures can be taken for adjustment based on the instability degree, the robustness of the conversion rate is effectively improved, and the emission risk is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of engine after-treatment, and particularly relates to an engine emission control method, device and vehicle. Background Art

[0002] The TWC (Three-Way Catalytic Converter) is a core component in the vehicle exhaust gas purification system. It is mainly used to treat harmful gases such as carbon monoxide, hydrocarbons, and nitrogen oxides emitted by the engine, and convert them into carbon dioxide, water, and nitrogen. This not only reduces the emission of harmful gases from vehicles, but also reduces air pollution, which is of great significance to environmental protection. The conversion efficiency of the three-way catalytic converter will directly affect whether the vehicle's exhaust gas meets the standards. How to keep the conversion efficiency of the three-way catalytic converter within an ideal range as much as possible to reduce the risk of exceeding the limit of the engine's exhaust gas emissions has become an urgent problem to be solved. Summary of the Invention

[0003] In view of the above problems, the present application provides an engine emission control method, device and vehicle to achieve the purpose of reducing the risk of exceeding the emission limit and improving the conversion stability. The specific solutions are as follows: In the first aspect of the present application, an engine emission control method is provided, including: Identifying an unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine after-treatment; When it is identified that the three-way catalytic converter is in the unstable state of efficiency, determining an efficiency risk value representing the degree of instability of the unstable state according to the monitored value of the second characteristic parameter; Adjusting the temperature of the three-way catalytic converter according to the heat 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, so that the three-way catalytic converter returns to the efficiency stable state and maintains the conversion efficiency in the efficiency stable state.

[0004] In a possible implementation, the identifying an unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine after-treatment includes: Determining whether there is a fluctuation in the conversion efficiency of the three-way catalytic converter according to the first statistical data of the monitored values of the first characteristic parameter within the first monitoring duration; When it is determined that there is a fluctuation in the conversion efficiency of the three-way catalytic converter, determining whether the three-way catalytic converter is in an unstable state of efficiency according to the second statistical data representing the continuous fluctuation of the conversion efficiency within the second monitoring duration.

[0005] In a possible implementation, the first characteristic parameter includes: the monitoring signal of the post-oxygen sensor, the first statistical data includes: the signal mean value of the monitoring signal, the signal oscillation amplitude when oscillation occurs, and the number of signal oscillations. Determining whether there is a fluctuation in the conversion efficiency of the three-way catalytic converter according to the first statistical data of the monitoring values of the first characteristic parameter within the first monitoring duration includes: If the signal mean value 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 there is a fluctuation in the conversion efficiency of the three-way catalytic converter.

[0006] In a possible implementation, the second statistical data includes: the fluctuation duration, the number of oscillation continuations, and the engine continuous work output. When it is determined that there is a fluctuation in the conversion efficiency of the three-way catalytic converter, determining whether the three-way catalytic converter is in an efficiency unstable state according to the second statistical data characterizing the continuous fluctuation of the conversion efficiency within the second monitoring duration includes: If the fluctuation duration is greater than a fourth threshold, or the number of oscillation continuations is greater than a fifth threshold, or the engine continuous work output is greater than a sixth threshold, it is determined that the three-way catalytic converter is in an efficiency unstable state.

[0007] In a possible implementation, the second characteristic parameter includes: the post-treatment temperature and an oscillation parameter characterizing the oscillation severity of the monitoring signal of the post-oxygen sensor. When it is identified that the three-way catalytic converter is in the efficiency unstable state, determining an efficiency risk value characterizing the unstable degree of the efficiency unstable state according to the monitoring values of the second characteristic parameter includes: Determining the efficiency risk value according to the temperature range where the temperature value of the post-treatment temperature is located and the oscillation degree range where the parameter value of the oscillation parameter is located.

[0008] In a 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: According to the current operating condition of the engine, adopting an exhaust gas temperature management strategy after engine coast-down or an exhaust gas temperature management strategy during positive work to adjust the temperature of the three-way catalytic converter; When the temperature of the three-way catalytic converter after adjustment does not reach the target temperature, adjusting the fuel supply of the engine according to the fuel injection strategy, and updating the reference value calibration table according to the fuel injection amount reaching the target temperature.

[0009] In a possible implementation, before identifying the unstable state of the efficiency of the three-way catalytic converter based on the monitored value of the first characteristic parameter of the engine aftertreatment, it further includes: Judging whether to perform the identification operation of the unstable state of the efficiency of the three-way catalytic converter according to the operating parameters of the engine and the working state of the oxygen sensor.

[0010] In a possible implementation, the judging whether to perform the identification operation of the unstable state of the efficiency 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, 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, it is determined to perform the identification operation of the unstable state of the efficiency of the three-way catalytic converter.

[0011] The second aspect of the present application provides an engine emission control device, including: A state identification module, configured to identify the unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine aftertreatment; A risk determination module, configured to determine an efficiency risk value characterizing the degree of instability of the efficiency unstable state according to the monitored value of the second characteristic parameter when it is identified that the three-way catalytic converter is in the efficiency unstable state; and, An emission adjustment module, configured to adjust the temperature of the three-way catalytic converter according to the heat 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 that the three-way catalytic converter is restored to the efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

[0012] The third aspect of the present application provides a vehicle, including a vehicle body and an electronic device disposed in the vehicle body, the electronic device includes at least one processor and a memory connected to the processor, wherein: The memory is used to store a computer program; The processor is configured 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 manner of the first aspect.

[0013] The fourth aspect of the present application provides a computer program product, including computer-readable instructions, when the computer-readable instructions run on an electronic device, enabling the electronic device to implement the engine emission control method as described in the first aspect or any implementation manner of the first aspect.

[0014] The fifth aspect of 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 manner of the first aspect described above.

[0015] By means of the above technical solution, for the engine emission control method provided by the present application, the efficiency unstable state of the three-way catalytic converter is identified by monitoring the first characteristic parameter of the engine post-treatment. When it is identified that the three-way catalytic converter is in an efficiency unstable state, the efficiency risk value representing the degree of instability of the efficiency unstable state is determined according to the monitored value of the second characteristic parameter. The temperature of the three-way catalytic converter is adjusted according to the heat 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 that the three-way catalytic converter is restored to an efficiency stable state and the conversion efficiency in the efficiency stable state is maintained. When it is detected that the three-way catalytic converter is in an efficiency unstable state, the engine emission control method can take corresponding measures for adjustment based on the degree of instability, maintain the conversion rate of the three-way catalytic converter at an ideal level, effectively improve the robustness of the conversion rate of the three-way catalytic converter, and reduce the emission risk. Description of the Drawings

[0016] Combined with the drawings and referring to the following specific embodiments, the above and other features, advantages and aspects of the embodiments of the present disclosure will become more obvious. 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 the original elements and elements are not necessarily drawn to scale.

[0017] Figure 1 It is a flowchart of an engine emission control method provided by the present application; Figure 2 It is a schematic diagram of an efficiency risk value provided by the present application; Figure 3 It is an architecture diagram of an engine post-treatment system provided by the present application; Figure 4 It is a structural diagram of an engine emission control device provided by the present application; Figure 5 It is a structural diagram of an electronic device provided by the present application. Detailed Embodiments

[0018] The following describes the embodiments of the present application with reference to the drawings in the embodiments of the present application. The terms used in the embodiments 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.

[0019] The embodiments of the present application will be described below with reference to the accompanying drawings. As is known to those of ordinary skill in the art, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0020] The terms "first", "second", etc. in the specification, claims and the above-mentioned drawings of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is only a way of distinguishing objects with the same attributes when describing the embodiments of the present application. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, so that a process, method, system, product or device comprising a series of units does not have to be limited to those units, but may include other units not clearly listed or inherent to these processes, methods, products or devices.

[0021] The role of the three-way catalytic converter in the engine after-treatment system is mainly reflected in its high conversion efficiency. The three-way catalytic converter can convert the main pollutants CO, HC, and NOx in vehicle exhaust into harmless carbon dioxide, water, and nitrogen, thereby significantly reducing environmental pollution. Among them, "rich-lean modulation" 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 operating conditions of the engine, so that an alternating rich mixture and lean mixture are formed inside the three-way catalytic converter, thereby optimizing the catalytic reaction process. It is directly related to its oxygen storage capacity, mainly reflected in the treatment limit under extreme air-fuel ratio conditions. Too rich or too lean has a great impact on the conversion efficiency of the three-way catalyst.

[0022] Currently, in order to maintain the conversion efficiency of the three-way catalytic converter, closed-loop control based on the post-oxygen sensor or the pre-oxygen sensor, or both combined, can be used to adjust the rich-lean modulation, and the conversion rate of the three-way catalytic converter can be adjusted by means of heat management regulation by increasing the burner, etc. These methods are relatively simple to control, and the effects are not ideal, and cannot achieve targeted adjustment of the reduction of the conversion efficiency of the three-way catalytic converter.

[0023] To solve the above problems, the embodiments of the present application provide an engine emission control method. The engine emission control method of the embodiments of the present application will be introduced in detail below with reference to the accompanying drawings.

[0024] Refer to Figure 1 , Figure 1 is a schematic flow chart of an engine emission control method provided by an embodiment of the present application. As shown in Figure 1As shown, an engine emission control method provided by an embodiment of the present application can be applied to an electronic control unit of an engine aftertreatment system. Here, the engine can be a fuel engine, such as a gas engine (natural gas engine, etc.), a fuel engine (gasoline engine, etc.). This engine emission control method can include steps 101 to 103, which will be described in detail below.

[0025] 101. Identify the unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine aftertreatment.

[0026] Specifically, referring to Figure 3 Shown is a structural diagram of an engine aftertreatment system, which mainly consists of a supercharger, a front oxygen sensor, an exhaust gas bypass valve, a TWC with exhaust gas bypass, a rear oxygen sensor, and an ECU (electronic control unit). The rear oxygen sensor is installed after the three-way catalytic converter, and its main task is to detect the oxygen content in the exhaust gas purified by the three-way catalytic converter. By comparing the data of the front oxygen sensor and the rear oxygen sensor, it can be judged whether the three-way catalytic converter is working properly. When the three-way catalytic converter works at a stable conversion efficiency, the relevant oxygen monitoring value of the rear oxygen sensor should also be stable. On the contrary, when the monitored value of the rear oxygen sensor fluctuates, it indicates that the working state of the three-way catalytic converter has abnormal, which will lead to a decrease in the conversion efficiency. Here, the first characteristic parameter can be the monitoring signal related to the rear oxygen sensor. By observing the monitored value, it is identified whether the three-way catalytic converter has an unstable conversion efficiency state.

[0027] 102. When it is identified that the three-way catalytic converter is in an unstable efficiency state, determine an efficiency risk value representing the degree of instability of the unstable efficiency state according to the monitored value of the second characteristic parameter.

[0028] Specifically, when it is identified that the three-way catalytic converter is in an unstable conversion efficiency state, for the convenience of subsequent targeted adjustment of the unstable state of the three-way catalytic converter, the degree of instability, that is, the fluctuation degree of the rear oxygen sensor signal, can be continuously judged through the second characteristic parameter, and then the degree of instability can be determined. Among them, for the convenience of taking targeted adjustment measures, the degree of instability can be characterized by an efficiency risk value. The efficiency risk value can be the temperature value of the treatment temperature, a parameter value representing the oscillation degree of the rear oxygen sensor signal, such as the standard deviation, etc. as the efficiency risk value. Then, according to the interval where these parameter values are located, the degree of instability of the conversion efficiency of the three-way catalytic converter is further determined.

[0029] 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 that the three-way catalytic converter is restored to an efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

[0030] On the basis of determining the efficiency risk value, corresponding adjustment measures are taken for adjustment according to the efficiency risk value. For example, targeted adjustment can be carried out according to the parameter values determined to be in a risk state included in the efficiency risk value. For example, when the temperature value of the treatment temperature is in a risk state, according to the current operating condition of the engine, the exhaust gas temperature management strategy after reverse towing or the exhaust gas temperature management strategy during positive work can be adopted to adjust the temperature of the three-way catalytic converter. When the parameter value of the oscillation parameter is in a risk state, the fuel supply of the engine can be adjusted according to the fuel injection strategy (that is, the fuel supply of the engine is adjusted to be rich or lean). When both of the above two parameters are in a risk state, first, according to the current operating condition of the engine, the exhaust gas temperature management strategy after reverse towing or the exhaust gas temperature management strategy during positive work can be adopted to adjust the temperature of the three-way catalytic converter. 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.

[0031] The exhaust gas temperature management after reverse towing: refers to the management of the temperature of the aftertreatment system when the engine is in a reverse towing state. The reverse towing state usually occurs when the vehicle decelerates or goes downhill, and the engine is in a reverse driving state. At this time, the engine does not generate power output, but still needs to maintain the temperature of the three-way catalytic converter. For example, when reverse towing, the exhaust gas bypass valve is opened to allow a part of the exhaust gas not to pass through the three-way catalytic converter, so that the temperature of the three-way catalytic converter is maintained at an ideal temperature.

[0032] The exhaust gas temperature management during positive work refers to the management of the temperature of the aftertreatment system when the engine is doing normal work. The positive work state means that the engine normally provides power output, and at this time, a large amount of heat is generated in the aftertreatment system. The exhaust gas temperature management during positive work ensures that the aftertreatment system operates within the optimal temperature range by optimizing the combustion process and exhaust gas treatment strategy. For example, the temperature is increased by adjusting the fuel injection amount and ignition timing (such as delaying the engine ignition angle).

[0033] The fuel injection strategy is to enrich or lean the fuel injection of the engine, so that the conversion efficiency of the three-way catalytic converter remains stable and is maintained at an ideal conversion efficiency value.

[0034] It can be understood that those skilled in the art can adjust and select the content of the above various adjustment measures as needed, which will not be elaborated here.

[0035] The engine emission control method can identify risks and classify them according to the key characteristic parameters of the engine after-treatment system. At the same time, corresponding measures are triggered according to the risk judgment status. Different risk levels correspond to different corresponding measures, and adaptive adjustment is carried out, which can make up for the efficiency deviation caused by factors such as ambient temperature, engine control, and after-treatment efficiency consistency, effectively improving the robustness of the TWC efficiency and reducing the emission control risk.

[0036] In one embodiment, to accurately identify the unstable state of the conversion efficiency of the three-way catalytic converter, step 101 above, which identifies the unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine after-treatment, may specifically include: Step 11: Determine whether there is a fluctuation in the conversion efficiency of the three-way catalytic converter according to the first statistical data of the monitored values of the first characteristic parameter within the first monitoring duration.

[0037] In one embodiment, the first characteristic parameter may include: the monitored signal of the post-oxygen sensor, and the first statistical data includes: the signal mean value of the monitored signal, the signal oscillation amplitude when oscillation occurs, and the number of signal oscillations. Then, if the signal mean value 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 there is a fluctuation in the conversion efficiency of the three-way catalytic converter. Here, the signal oscillation amplitude is the difference between two adjacent amplitudes when the post-oxygen sensor signal oscillates.

[0038] For example, during the continuous monitoring of the signal of the post-oxygen sensor, within a monitoring duration of 2 seconds, when the signal mean value > 0.2, the oscillation amplitude > 0.2, and the number of oscillations > 2 times, it can be determined that the conversion efficiency of the three-way catalytic converter has fluctuated and may be in an unstable state.

[0039] Step 12: When it is determined that there is a fluctuation in the conversion efficiency of the three-way catalytic converter, determine whether the three-way catalytic converter is in an efficiency unstable state according to the second statistical data indicating the continuous fluctuation of the conversion efficiency within the second monitoring duration.

[0040] In one embodiment, the second statistical data may include: the fluctuation duration, the number of continuous oscillations, and the continuous work done by the engine. Then, if the fluctuation duration is greater than the fourth threshold, or the number of continuous 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.

[0041] For example, when the fluctuation duration > 16s, or the number of continuous oscillations > 8 times, or the continuous work done by the engine > w0, that is, when any of the above conditions is met, it indicates 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 in an unstable state.

[0042] It is understandable that the above-mentioned respective thresholds can be adjusted as appropriate according to different engine signals, and no limitation is made here.

[0043] In some embodiments, in order to better characterize the instability degree of the unstable state of the conversion efficiency of the three-way catalytic converter, so as to facilitate the selection of subsequent adjustment measures, the second characteristic parameter includes: the post-treatment temperature and the oscillation parameter characterizing the severity of the oscillation of the monitoring signal of the post-oxygen sensor. Step 102, when it is recognized that the three-way catalytic converter is in an efficiency unstable state, determining an efficiency risk value characterizing the instability degree of the efficiency unstable state according to the monitored value of the second characteristic parameter may specifically include: Determining the efficiency risk value according to the temperature range where the temperature value of the post-treatment temperature is located and the oscillation degree range where the parameter value of the oscillation parameter is located.

[0044] Specifically, the oscillation parameter here can be the oscillation standard deviation obtained by statistically processing the signal of the post-oxygen sensor. The post-treatment temperature can be divided into three intervals, such as: 200 < temperature ≤ t0, t0 < temperature ≤ t1, t1 < temperature ≤ t2. The oscillation standard deviation is divided into three levels: st1(0.1), st2(0.2), st3(0.3), where the value in the parentheses is the corresponding standard deviation.

[0045] Refer to Figure 2 As shown, the adjusted intensity characterization obtained according to the divided intervals, where the abscissa is the temperature of the three-way catalytic converter (i.e., the post-treatment temperature), and the ordinate represents the corresponding oscillation standard deviation. It can be seen that 9 regions are formed by the intersection. Among them, from bottom to top, as the oscillation standard deviation increases, it indicates that the unstable state of the three-way catalytic converter gradually increases, and then the intensity of adjusting the fuel injection amount of the engine according to the signal of the post-oxygen sensor gradually increases. Similarly, from left to right, the intensity of the engine thermal management needs to be gradually increased. It can be seen that the 9 regions can respectively correspond to different adjustment intensities. When making adjustments, based on the corresponding relationship between the region and the adjustment intensity, the corresponding adjustment amplitude and intensity information can be determined, and targeted adjustments can be made.

[0046] And update the reference value calibration table according to the adjusted post-treatment temperature and the fuel injection amount reaching the target temperature, so as to facilitate direct calling during the next adjustment and improve the timeliness of the adjustment.

[0047] In other embodiments, considering that it is not necessary to judge the unstable state in all cases, to improve the accuracy and reliability of the recognition of the efficiency unstable state of the three-way catalytic converter. Before the above-mentioned step 101, identifying the efficiency unstable state of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine post-treatment, it may specifically further include: Based on 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 state of the three-way catalytic converter efficiency.

[0048] Specifically, when both the front oxygen sensor and the rear oxygen sensor are in the ready state, the engine coolant temperature is greater than the coolant 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, it is determined to perform the identification operation of the unstable state of the three-way catalytic converter efficiency.

[0049] For example, taking a certain natural gas engine as an example, when the working states of the front and rear oxygen sensors are ready, the engine is in a warm state (coolant temperature > 70°C), 200°C < TWC temperature < 450°C, 700 r / min < engine speed < 1900 r / min, and 10% < engine load rate < 100%, the subsequent identification operation of the unstable state of the conversion efficiency of the three-way catalytic converter can be carried out. Otherwise, the subsequent identification operation is no longer performed.

[0050] It should be noted that those skilled in the art can adjust and select the quantity of the above conditions and the values in the conditions according to different engine types, which will not be elaborated here.

[0051] The above introduces an engine emission control method provided by an embodiment of the present application. Next, the device for performing the above engine emission control method will be introduced.

[0052] Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of an engine emission control device provided by an embodiment of the present application. As Figure 4 shown, the engine emission control device includes: A state identification module 401, configured to identify the unstable state of the three-way catalytic converter efficiency according to the monitored value of the first characteristic parameter of the engine aftertreatment; A risk determination module 402, configured to determine an efficiency risk value characterizing the degree of instability of the efficiency unstable state according to the monitored value of the second characteristic parameter when it is identified that the three-way catalytic converter is in an efficiency unstable state; and, An emission adjustment module 403, configured 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 that the three-way catalytic converter is restored to an efficiency stable state and the conversion efficiency in the efficiency stable state is maintained.

[0053] In a possible implementation, the process of the state identification module 401 identifying the unstable state of the three-way catalytic converter efficiency according to the monitored value of the first characteristic parameter of the engine aftertreatment includes: Determine whether there is a fluctuation in the conversion efficiency of the three-way catalyst according to the first statistical data of the monitored values of the first characteristic parameter within the first monitoring duration; When it is determined that there is a fluctuation in the conversion efficiency of the three-way catalyst, determine whether the three-way catalyst is in an inefficiently stable state according to the second statistical data characterizing the continuous fluctuation of the conversion efficiency within the second monitoring duration.

[0054] In a possible implementation, the first characteristic parameter includes: the monitored signal of the post-oxygen sensor, and the first statistical data includes: the signal mean value of the monitored signal, the signal oscillation amplitude when oscillation occurs, and the number of signal oscillations. The process by which the state recognition module 401 determines whether there is a fluctuation in the conversion efficiency of the three-way catalyst according to the first statistical data of the monitored values of the first characteristic parameter within the first monitoring duration includes: If the signal mean value 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 there is a fluctuation in the conversion efficiency of the three-way catalyst.

[0055] In a possible implementation, the second statistical data includes: the fluctuation duration, the number of continuous oscillations, and the continuous work done by the engine. When it is determined that there is a fluctuation in the conversion efficiency of the three-way catalyst, the process by which the state recognition module 401 determines whether the three-way catalyst is in an inefficiently stable state according to the second statistical data characterizing the continuous fluctuation of the conversion efficiency within the second monitoring duration includes: If the fluctuation duration is greater than the fourth threshold, or the number of continuous 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 catalyst is in an inefficiently stable state.

[0056] In a possible implementation, the second characteristic parameter includes: the post-treatment temperature and the oscillation parameter characterizing the severity of the oscillation of the monitored signal of the post-oxygen sensor. The process by which the risk determination module 402 determines the efficiency risk value characterizing the degree of inefficient stability when identifying that the three-way catalyst is in an inefficiently stable state according to the monitored values of the second characteristic parameter includes: Determine the efficiency risk value according to the temperature range in which the temperature value of the post-treatment temperature is located and the oscillation degree range in which the parameter value of the oscillation parameter is located.

[0057] In a possible implementation, the process by which the emission adjustment module 403 adjusts the temperature of the three-way catalyst according to the heat 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: According to the current operating condition of the engine, adopt the exhaust temperature management strategy after engine coasting or the exhaust temperature management strategy during positive work to adjust the temperature of the three-way catalyst; When the temperature of the adjusted three-way catalytic converter does not reach the target temperature, adjust the fuel supply of the engine according to the fuel injection strategy, and update the reference value calibration table according to the fuel injection amount that reaches the target temperature.

[0058] In a possible implementation, it further includes: a monitoring enabling module, which is used to, before identifying the unstable state of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine aftertreatment: Judge whether to perform the identification operation of the unstable state of the three-way catalytic converter according to the operating parameters of the engine and the working state of the oxygen sensor.

[0059] In a possible implementation, the process in which the monitoring enabling module judges whether to perform the identification operation of the unstable 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, the water temperature of the engine is greater than the water temperature threshold, the temperature of its 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 state of the three-way catalytic converter.

[0060] An electronic device is also provided in the embodiments of the present application. Refer to Figure 5 As shown, it shows a schematic structural diagram of an electronic device suitable for implementing the electronic device in the embodiments of the present application. The electronic device in the embodiments of the present application may include, but is not limited to, such as an ECU (Electronic Control Unit, electronic controller unit), a VCU (Vehicle Control Unit, vehicle controller), an MCU (Micro Controller Unit, micro control unit), an HCU (Hybrid Control Unit, hybrid control system), etc. Figure 5 The electronic device shown is only an example and should not bring any limitation to the functions and usage scope of the embodiments of the present application.

[0061] As Figure 5 shown, the electronic device may include a processing device (such as a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 502 or the program loaded from the storage device 508 into the random access memory (RAM) 503. When the electronic device is powered on, various programs and data required for the operation of the electronic device are also stored in the RAM 503. The processing device 501, the ROM 502, and the RAM 503 are connected to each other through a bus 504. The input / output (I / O) interface 505 is also connected to the bus 504.

[0062] Typically, the following devices can be connected to the I / O interface 505: input devices 506 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; output devices 507 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 508 including, for example, a memory card, a hard disk, etc.; and a communication device 509. The communication device 509 can allow the electronic device to communicate with other devices wirelessly or wiredly to exchange data. Although Figure 5 an electronic device with various devices is shown, it should be understood that it is not required to implement or have all the shown devices. Instead, more or fewer devices can be implemented or had.

[0063] An embodiment of the present application also provides a computer program product including computer-readable instructions, which, when running on an electronic device, enable the electronic device to implement any one of the engine emission control methods provided by the embodiments of the present application.

[0064] An embodiment of the present application also provides a computer-readable storage medium carrying one or more computer programs, which, when executed by an electronic device, can enable the electronic device to implement any one of the engine emission control methods provided by the embodiments of the present application.

[0065] An embodiment of the present application also provides a vehicle including: a vehicle body and the electronic device as described in the above embodiment provided in the vehicle body.

[0066] In addition, it should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the drawings of the device embodiments provided by the present application, the connection relationships between the modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines.

[0067] 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. Of course, it can also be implemented by dedicated hardware including application-specific integrated circuits, dedicated CPUs, dedicated memories, dedicated components, etc. Generally, functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structures for implementing the same function can also be various, such as analog circuits, digital circuits or dedicated circuits, etc. However, for the present application, software program implementation is a better embodiment in more cases. Based on such an understanding, the technical solution of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a readable storage medium, such as a floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk or optical disc of a computer, etc., and includes several instructions to enable a computer device (which can be a personal computer, training device, or network device, etc.) to execute the methods described in various embodiments of the present application.

[0068] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product.

[0069] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general computer, a dedicated 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, computer, training device or data center to another website, computer, training device or data center in a wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. 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 or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

Claims

1. An engine emission control method, characterized in that, Including: Identifying an unstable state of the efficiency of the three-way catalytic converter based on a monitored value of a first characteristic parameter of engine aftertreatment; When it is identified that the three-way catalytic converter is in the unstable state of efficiency, determining an efficiency risk value characterizing the degree of instability of the unstable state of efficiency based on a monitored value of a second characteristic parameter; Adjusting the temperature of the three-way catalytic converter according to a heat management adjustment strategy corresponding to the efficiency risk value, and / or adjusting the fuel supply of the engine according to a fuel injection strategy corresponding to the efficiency risk value, so that the three-way catalytic converter is restored to a stable efficiency state and the conversion efficiency in the stable efficiency state is maintained.

2. The engine emission control method according to claim 1, characterized in that, The identifying an unstable state of the efficiency of the three-way catalytic converter based on a monitored value of a first characteristic parameter of engine aftertreatment includes: Determining whether there is a fluctuation in the conversion efficiency of the three-way catalytic converter according to first statistical data of the monitored value of the first characteristic parameter within a first monitoring duration; When it is determined that there is a fluctuation in the conversion efficiency of the three-way catalytic converter, determining whether the three-way catalytic converter is in an unstable state of efficiency according to second statistical data characterizing the continuous fluctuation of the conversion efficiency within a second monitoring duration.

3. The engine emission control method according to claim 2, characterized in that, The first characteristic parameter includes: the monitoring signal of the post-oxygen sensor, and the first statistical data includes: the signal mean value of the monitoring signal, the signal oscillation amplitude during oscillation, and the number of signal oscillations. The determining whether there is a fluctuation in the conversion efficiency of the three-way catalytic converter according to first statistical data of the monitored value of the first characteristic parameter within a first monitoring duration includes: If the signal mean value 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 there is a fluctuation in the conversion efficiency of the three-way catalytic converter.

4. The engine emission control method according to claim 2 or 3, characterized in that, The second statistical data includes: the fluctuation duration, the number of continuous oscillations, and the continuous work amount of the engine. The determining whether the three-way catalytic converter is in an unstable state of efficiency according to second statistical data characterizing the continuous fluctuation of the conversion efficiency within a second monitoring duration when it is determined that there is a fluctuation in the conversion efficiency of the three-way catalytic converter includes: If the fluctuation duration is greater than a fourth threshold, or the number of continuous oscillations is greater than a fifth threshold, or the continuous work amount of the engine is greater than a sixth threshold, it is determined that the three-way catalytic converter is in an unstable state of efficiency.

5. The engine emission control method according to claim 1, characterized in that, The second characteristic parameter includes: the aftertreatment temperature and an oscillation parameter characterizing the severity of the oscillation of the monitoring signal of the post-oxygen sensor. The determining an efficiency risk value characterizing the degree of instability of the unstable state of efficiency based on a monitored value of a second characteristic parameter when it is identified that the three-way catalytic converter is in the unstable state of efficiency includes: Determining the efficiency risk value according to the temperature range where the temperature value of the aftertreatment temperature is located and the oscillation degree range where the parameter value of the oscillation parameter is located.

6. The engine emission control method according to claim 1, wherein The adjusting the temperature of the three-way catalytic converter according to a heat management adjustment strategy corresponding to the efficiency risk value, and / or adjusting the fuel supply of the engine according to a fuel injection strategy corresponding to the efficiency risk value includes: According to the current operating condition of the engine, adopt the exhaust gas temperature management strategy after engine coasting or the exhaust gas temperature management strategy during positive work to adjust the temperature of the three-way catalytic converter; When the temperature of the three-way catalytic converter after adjustment does not reach the target temperature, adjust the fuel supply of the engine according to the fuel injection strategy, and update the reference value calibration table according to the fuel injection amount to reach the target temperature.

7. The engine emission control method according to claim 1, characterized in that, Before identifying the unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine aftertreatment, it further includes: Judge whether to perform the identification operation of the unstable state of the efficiency of the three-way catalytic converter according to the operating parameters of the engine and the working state of the oxygen sensor.

8. The engine emission control method according to claim 7, wherein The judging whether to perform the identification operation of the unstable state of the efficiency 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, 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 state of the efficiency of the three-way catalytic converter.

9. An engine emission control device, characterized in that, It includes: A state identification module, configured to identify the unstable state of the efficiency of the three-way catalytic converter according to the monitored value of the first characteristic parameter of the engine aftertreatment; A risk determination module, configured to determine an efficiency risk value characterizing the degree of instability of the efficiency unstable state according to the monitored value of the second characteristic parameter when it is identified that the three-way catalytic converter is in the efficiency unstable state; and, An emission adjustment module, configured 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 that the three-way catalytic converter is restored to an efficiency stable state and maintain the conversion efficiency in the efficiency stable state.

10. A vehicle, characterized in that, It includes a vehicle body and an electronic device arranged in the vehicle body. The electronic device includes 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 that the electronic device can implement the engine emission control method according to any one of claims 1 to 8.

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