Post-oxidation voltage adjustment-based emission optimization control method, module and vehicle
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SAIC GM WULING AUTOMOBILE CO LTD
- Filing Date
- 2026-02-12
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies lack effective emission optimization strategies to reduce emissions of pollutants such as NMHC and NOx in the high-speed and ultra-high-speed segments of the WLTC cycle, especially after the catalyst has entered closed-loop control, emission control in these stages has not received sufficient attention.
By identifying engine operating conditions during specific operating phases, the deviation between actual and target post-oxygen voltage is obtained, and corresponding emission optimization strategies are selected, including adjusting the parameters of the post-oxygen window correlation function and the post-oxygen closed-loop PI control strength correlation function, in order to achieve optimized emission control.
It effectively reduces the emissions of pollutants such as NMHC and NOx in the high-speed and ultra-high-speed ranges of the WLTC cycle, improves control accuracy and robustness, and meets regulatory limits.
Smart Images
Figure CN122260804A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of engine emission control technology, specifically relating to an emission optimization control method, module, and vehicle based on post-oxygen voltage adjustment. Background Technology
[0002] The "Limits and Measurement Methods for Pollutant Emissions from Light-Duty Vehicles (China VI Stage)" (i.e., China VI B Stage, GB18352.6-2016) has been fully implemented. This regulation introduces the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) in the cold start emission test (Type I test) at ambient temperature, and sets strict limits for various pollutants emitted in the cycle, including total hydrocarbons (THC), non-methane hydrocarbons (NMHC), nitrogen oxides (NOx), carbon monoxide (CO), particulate matter (PM), and particulate number (PN). Therefore, ensuring the emission control system has high stability and robustness under various operating conditions is of great significance for emission calibration and optimization.
[0003] Currently, industry-wide emission optimization and control strategies primarily focus on the engine cold start phase (mainly controlling raw emissions, i.e., "original emissions") and the catalytic converter heating phase. This is because, in the WLTC cycle pollutant composition analysis, emissions generated during the cold start phase account for a significant proportion. Therefore, existing technologies generally utilize the Engine Control Module (ECM) to optimize key control parameters such as fuel injection strategies, variable valve timing angles, and ignition angles in these two phases to reduce raw emissions and promote rapid ignition of the three-way catalytic converter.
[0004] However, in actual vehicle development and calibration, due to factors such as vehicle dispersion, extensive Type I tests have revealed that, in addition to the cold start and catalytic converter heating stages, NMHC and NOx pollutants are also easily generated in the high-speed (Bag 3) and ultra-high-speed (Bag 4) segments of the WLTC cycle. Emission control in this stage primarily relies on the closed-loop control system of the vehicle's catalytic converter. Its core components include monitoring the voltage signals of the front and rear oxygen sensors, setting the rear oxygen window, long-term correction of the rear oxygen self-learning value, and closed-loop PID control logic. Although theoretical research on this closed-loop control system is relatively mature, there is still no suitable emission optimization strategy for these pollutants.
[0005] Therefore, there is an urgent need for an emission optimization strategy to reduce the emissions of pollutants such as NMHC and NOx in the high-speed and ultra-high-speed segments of the WLTC cycle. Summary of the Invention
[0006] The purpose of this application is to solve the problems existing in the prior art and provide an emission optimization control method, module and vehicle based on post-oxygen voltage adjustment, which fills the gap in emission optimization of WLTC cycle high-speed and ultra-high-speed segments and can effectively reduce the emission of pollutants such as NMHC and NOx in WLTC cycle high-speed and ultra-high-speed segments.
[0007] This application is achieved through the following technical solution:
[0008] The first aspect of the invention provides an emission optimization control method based on post-oxygen voltage adjustment, the control method comprising: In the vehicle emissions test cycle, identify the engine operating conditions that correspond to excessive pollutant emissions during specific operating phases; Based on the engine operating conditions, the actual post-oxygen voltage and the target post-oxygen voltage are obtained; Based on the deviation between the actual post-oxygen voltage and the target post-oxygen voltage, a corresponding emission optimization strategy is selected; Implement the selected optimization strategy and repeat the above steps based on the optimization results until emissions meet the requirements.
[0009] Preferably, the specific operating phase is the high-speed and / or ultra-high-speed phase of the WLTC test cycle, and the catalyst has entered a closed-loop control state.
[0010] Preferably, the corresponding emission optimization strategy is selected, including: If the difference between the actual post-oxygen voltage and the target post-oxygen voltage exceeds a first preset threshold, then a first optimization strategy is executed. The first optimization strategy is used to adjust the parameters in the post-oxygen window correlation function corresponding to the engine operating condition. If the difference does not exceed the first preset threshold, but the actual post-oxygen voltage fluctuates around the target post-oxygen voltage and the fluctuation amplitude exceeds the second preset threshold, then the second optimization strategy is executed. The second optimization strategy is used to adjust the parameters in the post-oxygen closed-loop PI control force correlation function.
[0011] Preferably, the first optimization strategy includes: Based on whether the actual post-oxygen voltage is greater than or less than the target post-oxygen voltage, the parameters in the post-oxygen window related function corresponding to the engine operating condition are increased or decreased accordingly by one or more preset adjustment steps.
[0012] Preferably, the second optimization strategy includes: The actual post-oxygen voltage and the target post-oxygen voltage are converted into the actual air-fuel ratio and the target air-fuel ratio; Based on the difference between the target air-fuel ratio and the actual air-fuel ratio, the parameters in the corresponding coordinate of the post-oxygen closed-loop PI control force correlation function are increased or decreased accordingly by one or more preset adjustment steps.
[0013] Preferably, identifying the engine operating conditions corresponding to excessive pollutant emissions during a specific operating phase includes: Second-level emission data during the test cycle is obtained using emission testing equipment; By combining data from the engine control module, the engine speed and load conditions corresponding to the pollutants exceeding the standard can be located.
[0014] Preferably, before executing the selected optimization strategy, the method further includes: Check whether the post-oxygen self-learning function used to compensate for long-term deviations in air-fuel ratio is in normal working condition; If not, perform a fault check on the front oxygen sensor closed-loop control or the rear oxygen sensor window.
[0015] Preferably, the above steps are repeated based on the optimization effect until the emissions meet the requirements, including: Emissions tests were conducted again after optimization. If the relationship between the actual post-oxygen voltage and the target post-oxygen voltage meets the preset conditions, the optimization ends. Otherwise, continue with the optimization process until emissions meet the requirements.
[0016] A second aspect of this application provides an engine control module for executing the emission optimization control method based on post-oxygen voltage adjustment as described in any of the preceding claims.
[0017] A third aspect of this application provides a vehicle that includes the engine control module described above.
[0018] Compared with the prior art, the beneficial effects of this application are: This application provides an emission optimization control method based on post-oxygen voltage diagnosis and parameter iterative calibration, which fills the gap in emission optimization of the high-speed and ultra-high-speed segments of the WLTC cycle, improves control accuracy and robustness, effectively solves the technical problem of excessive emissions in the high-speed and ultra-high-speed segments of the WLTC test cycle, and can effectively reduce the emissions of pollutants such as NMHC and NOx in the high-speed and ultra-high-speed segments of the WLTC cycle. Attached Figure Description
[0019] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.
[0020] Figure 1 A schematic flowchart of an emission optimization control method based on post-oxygen voltage adjustment provided in an embodiment of this application; Figure 2 A schematic diagram of another emission optimization control method based on post-oxygen voltage adjustment provided in an embodiment of this application; Figure 3 A catalytic converter window diagram provided for an embodiment of this application; Figure 4 A schematic diagram of the closed-loop control principle of the catalyst provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of an engine control module provided in an embodiment of this application. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. Based on the embodiments of this application described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of this application.
[0022] To address the lack of optimized methods in existing technologies for reducing emissions of NMHC, NOx, and other pollutants during the high-speed and ultra-high-speed phases of the WLTC cycle, this application proposes an emission optimization control method based on post-oxygen voltage adjustment. This method fills the gap in emission optimization for the high-speed and ultra-high-speed phases of the WLTC cycle and can effectively reduce emissions of NMHC, NOx, and other pollutants during these phases. The following is a further detailed description of this application with reference to the accompanying drawings.
[0023] Figure 1 A schematic flowchart of an emission optimization control method based on post-oxygen voltage adjustment provided in this application embodiment is shown below. Figure 1 This application describes an emission optimization control method based on post-oxygen voltage adjustment provided by an embodiment of the present application.
[0024] like Figure 1 As shown, the emission optimization control method based on post-oxygen voltage adjustment in this application includes at least the following steps S100 to S400.
[0025] Step S100: In the vehicle emission test cycle, identify the engine operating conditions corresponding to the excessive emission of pollutants in a specific operating phase.
[0026] The vehicle emissions test cycle refers to a standardized vehicle driving test procedure conducted for regulatory certification. It simulates a series of typical driving conditions (such as idling, acceleration, cruising, and deceleration) to measure the vehicle's average emissions level and fuel / electricity consumption throughout the cycle. In this application, the vehicle emissions test cycle is the WLTC test cycle. The WLTC cycle mainly consists of four parts: low-speed (bag1), medium-speed (bag2), high-speed (bag3), and ultra-high-speed (bag4).
[0027] A specific operating phase refers to one or more segments within the entire standardized test cycle that receive special attention and have specific problems identified. In this application, it refers to the high-speed segment (bag 3) and / or ultra-high-speed segment (bag 4) of the WLTC test cycle. Depending on the test vehicle (pure gasoline vehicle and hybrid vehicle), the cold start and catalytic converter heating phases mainly occur in bag 1 and bag 2. In the high-speed segment (bag 3) and / or ultra-high-speed segment (bag 4), where the catalytic converter has fully ignited and entered closed-loop control, emissions exceeding standards (especially NMHC and NOx) can still occur due to issues such as closed-loop control accuracy, which has been overlooked in previous optimization strategies. Engine operating condition refers to the engine's operating state at a certain moment, which can be uniquely determined by two basic parameters: engine speed (crankshaft revolutions per minute) and engine load (a parameter characterizing the engine's output power, usually indirectly expressed by intake air volume, torque percentage, or fuel injection quantity).
[0028] Step S200: Based on the engine operating conditions, obtain the actual post-oxygen voltage and the target post-oxygen voltage.
[0029] The actual post-oxygen voltage can be collected by an oxygen sensor installed after the three-way catalytic converter, which directly reflects the oxygen concentration in the exhaust gas after purification by the catalytic converter. Stable voltage indicates high catalytic converter conversion efficiency and precise closed-loop control; drastic voltage fluctuations or continuous deviations indicate control problems or decreased catalytic converter efficiency. The target post-oxygen voltage is an ideal voltage value calculated internally by the ECM or obtained by looking up a table. For example, the ECM can obtain it from the map (MAP) of post-oxygen window correlation functions stored in the ECM based on the current engine speed and load (i.e., the operating condition located in step S100).
[0030] Step S300: Select the corresponding emission optimization strategy based on the deviation between the actual post-oxygen voltage and the target post-oxygen voltage.
[0031] Specifically, this application proposes two strategies: If the difference between the actual post-oxygen voltage and the target post-oxygen voltage exceeds a first preset threshold, then a first optimization strategy is executed. The first optimization strategy is used to adjust the parameters in the post-oxygen window correlation function corresponding to the engine operating condition. If the difference does not exceed the first preset threshold, but the actual post-oxygen voltage fluctuates around the target post-oxygen voltage and the fluctuation amplitude exceeds the second preset threshold, then the second optimization strategy is executed. The second optimization strategy is used to adjust the parameters in the post-oxygen closed-loop PI control force correlation function.
[0032] Step S400: Execute the selected optimization strategy and repeat the above steps based on the optimization effect until the emissions meet the requirements.
[0033] Specifically, when executing the selected optimization strategy, the strategy selected in step S300 can be used to modify the corresponding MAP parameters in the ECM in a directional and step-wise manner through a calibration tool (such as INCA), and the new data can be written into the ECM. After applying the new parameters, in the next WLTC test, the performance of the original out-of-range operating point is evaluated based on the deviation between the actual post-oxygen voltage and the target post-oxygen voltage.
[0034] This application provides an emission optimization control method based on post-oxygen voltage diagnosis and parameter iterative calibration, filling the gap in emission optimization for the high-speed and ultra-high-speed segments of the WLTC cycle. It improves control accuracy and robustness, effectively solving the technical problem of exceeding emission standards in the high-speed and ultra-high-speed segments of the WLTC test cycle, and can effectively reduce the emissions of pollutants such as NMHC and NOx in the high-speed and ultra-high-speed segments of the WLTC cycle. Furthermore, this optimized control strategy has significant universality, providing important reference for different types of vehicles, such as gasoline vehicles and hybrid vehicles, and for Type I tests under different technical conditions, such as with or without Exhaust Gas Recirculation (EGR).
[0035] Figure 2 A logic diagram of another emission optimization control method based on post-oxygen voltage adjustment provided in this application embodiment is shown below. Next, refer to... Figure 2 Another emission optimization control method based on post-oxygen voltage adjustment provided in the embodiments of this application will be specifically described.
[0036] S101, Operating Condition Identification.
[0037] The goal of this step is to precisely pinpoint the specific engine operating condition point that needs to be optimized within the WLTC cycle.
[0038] During the Type I test, two key data points were recorded simultaneously: Use emission testing equipment (such as CVS) to collect second-level emission data and accurately record the instantaneous concentrations of pollutants such as THC, NMHC, NOx, and CO.
[0039] Use engine calibration software (such as INCA) to read and record the internal data stream of the engine control module, including engine speed, engine load, front oxygen sensor voltage, and actual rear oxygen voltage U. 实 Target post-oxygen voltage U 目 Post-oxygen self-learning value dlatrmo, etc.
[0040] After the test, the second-level emission data and ECM data were strictly aligned on the timeline. Based on the limits set by the China VI B regulations, the emission data was analyzed to identify the precise moment when pollutant concentrations exceeded the limits. Based on this moment, the corresponding ECM data was retrieved to determine the specific engine operating condition that caused the exceedance; this condition is uniquely determined by engine speed and engine load.
[0041] S102, Basic inspection of closed-loop control system.
[0042] Figure 3 A catalytic converter window diagram provided for an embodiment of this application; as shown Figure 3 As shown in the figure, the horizontal axis represents the excess air coefficient λ, where λ=1 represents the stoichiometric air-fuel ratio (the ideal ratio for gasoline combustion is 14.7:1). Figure 3 The dashed line represents the concentration changes of hydrocarbons (HC), CO, and NOx in the exhaust gas without a catalytic converter; the solid line represents the residual concentrations of these harmful gases after purification with a catalytic converter. The gray rectangle represents the conversion range, 0.997 < λ < 0.999. It can be seen that the purification efficiency of the catalytic converter is highest only within this conversion range. When the air-fuel ratio is within this range, the overall pollutant emissions are lowest; this air-fuel ratio range is also called the catalytic converter window.
[0043] The purpose of closed-loop control is to control the demand air-fuel ratio as accurately as possible, so that the air-fuel ratio falls within the catalytic converter window, at which point the catalytic converter conversion efficiency is optimal, thereby reducing emissions. Figure 4 This is a schematic diagram of the closed-loop control principle of the catalyst provided in the embodiments of this application; as follows: Figure 4 As shown, the system uses a target air-fuel ratio λ 目 Based on this, the air-fuel mixture is first prepared and injected into the engine for combustion; the front oxygen sensor detects the raw exhaust gas after combustion to obtain the actual air-fuel ratio λ. 实 After the exhaust gas is purified by the catalytic converter, the post-oxygen sensor detects the voltage U of the purified exhaust gas. 实 Then, the correction amount is calculated through voltage-to-air-fuel ratio conversion MAP and PI / PID control algorithms, and finally the fuel injection is adjusted to stabilize the actual air-fuel ratio near the target value (λ≈1), ensuring that the catalytic converter efficiently purifies the exhaust gas. Among these adjustments, the actual after-oxygen voltage U...实 It can detect the conversion efficiency of the catalyst and the target post-oxygen voltage U. 目 The ideal value of the post-oxygen voltage is the value that keeps the air-fuel ratio at the catalytic converter window; the post-oxygen self-learning value dlatrmo is the continuous learning and compensation for the air-fuel ratio deviation, which runs through the entire vehicle life cycle and affects the stability of emissions; therefore, these three items are of great significance to the pollutant control of the specific stage described in S101.
[0044] Before performing in-depth optimization, it is necessary to ensure that the closed-loop control system itself is functioning correctly to avoid making ineffective adjustments based on errors. Therefore, a self-learning function check is required. The following is a detailed explanation of the self-learning function check.
[0045] For the out-of-standard operating conditions located in S101, check the post-oxygen self-learning value (dlatrmo) in the time period near that point.
[0046] If dlatrmo has a valid value (non-zero or invalid) and shows a continuous and slow trend of change within the observation time (e.g., 10 seconds), then the post-oxygen self-learning function used to compensate for long-term deviations in air-fuel ratio is determined to be in normal working condition, the closed-loop control is normal, and subsequent optimization can be carried out.
[0047] If dlatrmo has no value, is invalid, or remains unchanged for a long period, it indicates that the basic adaptive mechanism of the closed-loop control has failed. In this case, a basic check of the vehicle status should be performed first, such as performing a front oxygen sensor closed-loop function check and a rear oxygen sensor window calibration check, to rule out underlying faults.
[0048] S103, Post-oxygen voltage deviation determination and strategy selection.
[0049] This step is the core of the optimization decision-making process, intelligently selecting the optimal path based on the actual performance of the post-oxygen voltage.
[0050] Steady-state deviation determination (triggering the first optimization strategy): Calculate U under the condition of exceeding the standard. 实 with U 目 The difference ΔU. Set a first preset threshold, for example, ±0.03V.
[0051] If |△U|≥0.03V, it indicates a significant steady-state deviation and that the system target setting is inaccurate. In this case, the process switches to execute the first optimization strategy (S104a).
[0052] If |△U|<0.03V, proceed to the next judgment.
[0053] Dynamic fluctuation determination (triggering the second optimization strategy): If the steady-state deviation is small, further analysis of U is performed. 实 Quality control. Observe U 实 with U目 The fluctuations.
[0054] If the fluctuation amplitude (e.g., obtained by calculating the standard deviation or peak-to-peak value) exceeds a second preset threshold (e.g., 0.05V), it indicates that the dynamic performance of the closed-loop control is poor, with oscillations or slow response. At this time, the process switches to execute the second optimization strategy (S104b).
[0055] If the fluctuation range is also below the threshold, it indicates that the current oxygen voltage control is already quite ideal, and the optimization judgment for this operating point can be terminated.
[0056] S104a, Implementation of the first optimization strategy – Adjustment of the oxygen window correlation function.
[0057] This strategy addresses the steady-state deviation problem by optimizing control through calibration of the target benchmark.
[0058] The post-oxygen window related functions are represented as a two-dimensional lookup table (MAP) in the ECM. The horizontal axis (X-axis) of this MAP is the engine speed, and the vertical axis (Y-axis) is the engine load. The parameter value (Z value) stored in each cell of the table is the target post-oxygen voltage reference under the corresponding operating condition.
[0059] Execution steps: Locate the MAP point: Based on the out-of-range operating conditions (speed N, load L) located by S101, find the coordinate point (N, L) in the MAP.
[0060] Determine the adjustment direction and step size: If S103 is determined to be U 实 >U 目 Then U needs to be 实 Lower to get closer to U 目 Therefore, the parameter value (Z value) at the MAP point (N,L) should be increased.
[0061] If U 实 目 If so, the parameter value at that point should be reduced.
[0062] Adjustment in steps: The adjustment range is measured in preset adjustment steps. The preset adjustment step is a minimum adjustment amount pre-set according to calibration accuracy requirements. For example, it can be set to 0.005V. In practice, adjustments can be made in 1 to 5 steps (i.e., n=1 to 5). Initial optimization usually starts with adjusting one step.
[0063] Using a calibration tool, the parameter values of the post-oxygen window correlation function MAP at point (N,L) are modified according to the above direction and step size.
[0064] S104b: Implementation of the second optimization strategy - adjustment of the oxygen closed-loop PI control intensity correlation function.
[0065] This strategy addresses dynamic fluctuation issues by improving system response through optimizing controller parameters.
[0066] The post-oxygen closed-loop PI control force correlation function is also a MAP. Its horizontal axis (X-axis) is usually the air-fuel ratio deviation (Δλ), and the table content (Z value) is the controller's proportional gain coefficient (Kp) and / or integral gain coefficient (Ki). These parameters together determine the response speed and stability of the closed-loop control.
[0067] Execution steps: Data conversion: Using the post-oxygen voltage (U) and air-fuel ratio (λ) conversion function MAP stored internally in the ECM, U is converted... 实 and U 目 Convert to λ respectively 实 and λ 目 .
[0068] Calculation of deviation: Calculate the instantaneous air-fuel ratio deviation Δλ = λ 目 -λ 实 .
[0069] Positioning and Adjustment: Based on the calculated Δλ value, find the corresponding coordinate region in the PI control force correlation function MAP.
[0070] If the fluctuation manifests as control overshoot or oscillation, the proportional gain coefficient (Kp) parameter value corresponding to that region can be decreased; if it manifests as sluggish response or slow deviation elimination, the integral gain coefficient (Ki) parameter value corresponding to that region can be increased.
[0071] Adjustments are also made using a preset adjustment step size. For the PI coefficient, the step size can be an absolute value (e.g., 0.1) or a relative percentage (e.g., 5%). The number of adjustment steps, n, can also be selected between 1 and 5.
[0072] The calibration tool allows for the modification of the Kp or Ki parameters of the corresponding points in the MAP, specifying the direction and step size.
[0073] S105: Iterative verification and process closure.
[0074] Optimization is not something that can be achieved overnight; it requires verification to form a closed loop.
[0075] After completing the parameter adjustments for S104a or S104b, a new ECM calibration data file is generated and flashed into the vehicle's ECM. Subsequently, the complete WLTC Cycle Type I test is re-executed under the same environmental and test conditions.
[0076] Then, an effectiveness evaluation will be conducted. New test data will be analyzed, with a focus on the original out-of-specification operating conditions. If U 实 with U 目If the difference |△U| is less than 0.03V and its fluctuation range is also less than 0.05V, then the preset conditions are met, the optimization target for this operating point is achieved, and the optimization can be terminated.
[0077] If the above conditions are still not met, the entire process from S101 to S105 is repeated for the next iteration of optimization. In subsequent iterations, the step size n or fine-tuning strategy can be selected more precisely based on the results of the previous iteration.
[0078] This method is applied cyclically to optimize all identified emission exceedance conditions in the WLTC cycle bag3 and bag4 stages until the vehicle's Type I test emission results fully meet regulatory limits.
[0079] By implementing the control strategy provided in this embodiment, the problem of excessive emissions in the high-speed and ultra-high-speed sections of WLTC can be solved systematically and in a data-driven manner.
[0080] This application also provides an engine control module, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in any of the method embodiments described above.
[0081] Next, refer to Figure 5 This describes an example engine control module 100 for implementing the emission optimization control method based on post-oxygen voltage adjustment according to embodiments of this application.
[0082] like Figure 5 As shown, the engine control module 100 includes a processor 110, a memory 120, and a communication interface 130. The processor 110, memory 120, and communication interface 130 can be interconnected and communicate via a communication bus 140 and / or other forms of connection mechanisms (not shown).
[0083] It should be noted that Figure 5 The components and structure of the engine control module 100 shown are merely exemplary and not limiting; the engine control module may also have other components and structures as needed.
[0084] Optionally, the communication interface 130 may also include a transmitter and / or a receiver.
[0085] The processor 110 may be a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), a microcontroller and embedded device, or other processing units with data processing capabilities and / or instruction execution capabilities.
[0086] The memory 120 can be various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM), cache memory, synchronous dynamic random access memory (SDRAM), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may also be stored on the computer-readable storage medium, and the memory 120 can execute the program instructions to implement the emission optimization control method based on post-oxygen voltage adjustment described in the embodiments of this application above.
[0087] The ECM internally contains the post-oxygen window correlation function MAP, the post-oxygen closed-loop PI control strength correlation function MAP, and control logic for executing the above-mentioned emission optimization control method based on post-oxygen voltage adjustment.
[0088] This application also provides a vehicle that includes the engine control module described above, as well as an engine, a three-way catalytic converter, and front and rear oxygen sensors. This vehicle has the capability to apply the above methods for emission optimization during the research and development calibration phase and achieve stable, low-emission closed-loop control in mass-produced vehicles.
[0089] Finally, it should be noted that the above technical solution is only one implementation method of this application. For those skilled in the art, based on the application methods and principles disclosed in this application, it is easy to make various types of improvements or modifications, and not limited to the methods described in the specific implementation methods above. Therefore, the methods described above are only preferred and have no limiting significance.
Claims
1. An emission optimization control method based on post-oxygen voltage adjustment, characterized in that: The control method includes: In the vehicle emissions test cycle, identify the engine operating conditions that correspond to excessive pollutant emissions during specific operating phases; Based on the engine operating conditions, the actual post-oxygen voltage and the target post-oxygen voltage are obtained; Based on the deviation between the actual post-oxygen voltage and the target post-oxygen voltage, a corresponding emission optimization strategy is selected; Implement the selected optimization strategy and repeat the above steps based on the optimization results until emissions meet the requirements.
2. The emission optimization control method based on post-oxygen voltage adjustment according to claim 1, characterized in that, The specific operating phase refers to the high-speed and / or ultra-high-speed phases of the WLTC test cycle, and the catalyst has entered a closed-loop control state.
3. The emission optimization control method based on post-oxygen voltage adjustment according to claim 2, characterized in that, Select the appropriate emission optimization strategy, including: If the difference between the actual post-oxygen voltage and the target post-oxygen voltage exceeds a first preset threshold, then a first optimization strategy is executed. The first optimization strategy is used to adjust the parameters in the post-oxygen window correlation function corresponding to the engine operating condition. If the difference does not exceed the first preset threshold, but the actual post-oxygen voltage fluctuates around the target post-oxygen voltage and the fluctuation amplitude exceeds the second preset threshold, then the second optimization strategy is executed. The second optimization strategy is used to adjust the parameters in the post-oxygen closed-loop PI control force correlation function.
4. The emission optimization control method based on post-oxygen voltage adjustment according to claim 3, characterized in that, The first optimization strategy includes: Based on whether the actual post-oxygen voltage is greater than or less than the target post-oxygen voltage, the parameters in the post-oxygen window related function corresponding to the engine operating condition are increased or decreased accordingly by one or more preset adjustment steps.
5. The emission optimization control method based on post-oxygen voltage adjustment according to claim 3, characterized in that, The second optimization strategy includes: The actual post-oxygen voltage and the target post-oxygen voltage are converted into the actual air-fuel ratio and the target air-fuel ratio; Based on the difference between the target air-fuel ratio and the actual air-fuel ratio, the parameters in the corresponding coordinate of the post-oxygen closed-loop PI control force correlation function are increased or decreased accordingly by one or more preset adjustment steps.
6. The emission optimization control method based on post-oxygen voltage adjustment according to claim 1, characterized in that, Identify engine operating conditions corresponding to excessive pollutant emissions during specific operational phases, including: Second-level emission data during the test cycle is obtained using emission testing equipment; By combining data from the engine control module, the engine speed and load conditions corresponding to the pollutants exceeding the standard can be located.
7. The emission optimization control method based on post-oxygen voltage adjustment according to claim 1, characterized in that, Before executing the selected optimization strategy, the following is also included: Check whether the post-oxygen self-learning function used to compensate for long-term deviations in air-fuel ratio is in normal working condition; If not, perform a fault check on the front oxygen sensor closed-loop control or the rear oxygen sensor window.
8. The emission optimization control method based on post-oxygen voltage adjustment according to claim 1, characterized in that, Repeat the above steps based on the optimization results until emissions meet the requirements, including: Emissions tests were conducted again after optimization. If the relationship between the actual post-oxygen voltage and the target post-oxygen voltage meets the preset conditions, the optimization ends. Otherwise, continue with the optimization process until emissions meet the requirements.
9. An engine control module, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the emission optimization control method based on post-oxygen voltage adjustment as described in any one of claims 1 to 8.
10. A vehicle, characterized in that, The vehicle includes the engine control module as described in claim 9.