Dynamic correction control method, control unit and system for DPF regeneration cycle and diesel engine

Abstract

The invention relates to the technical field of regeneration control, in particular to a dynamic correction control method, control unit and system for a DPF regeneration cycle and a diesel engine, and the method comprises the steps that the exhaust flow, the current DPF carbon loading capacity, the front exhaust temperature and the accumulated mileage and time after last regeneration are obtained in real time; and when a preset correction enabling condition is met, a pre-calibration mapping table is inquired based on the exhaust flow, the carbon loading capacity and the temperature, and corresponding flow, carbon loading capacity and temperature correction factors are determined. And performing dynamic deduction calculation on the accumulated mileage and time by using the three correction factors to obtain corrected mileage and time. And if the corrected mileage or time exceeds a higher first set threshold value, or the current carbon loading capacity of the DPF exceeds a safety threshold value, regeneration is triggered immediately. And through working condition self-adaptive dynamic deduction, the regeneration period is intelligently prolonged, unnecessary regeneration is reduced, and oil saving and consumption reduction are achieved while safety is guaranteed.

Description

Technical Field

[0001] This application relates to the field of regeneration control technology, specifically to a dynamic correction control method, control unit, system, and diesel engine for DPF regeneration cycle. Background Technology

[0002] Existing diesel particulate filter (DPF) regeneration triggering strategies suffer from insufficient intelligence and poor economic efficiency. Mainstream solutions primarily rely on fixed mileage, operating time, or conservative carbon load thresholds as triggering conditions. For example, when a vehicle accumulates a preset fixed mileage or time, active regeneration is forcibly triggered regardless of the actual carbon deposit state of the DPF or the engine's current operating conditions.

[0003] While this fixed triggering method can ensure the safety of the DPF, its design is too conservative and crude, and has drawbacks: It completely ignores the significant differences in carbon soot generation rates and DPF passive regeneration capabilities under different vehicle operating conditions. Under high-speed, high-load operating conditions, with high exhaust temperatures and large flow rates, the DPF possesses a strong passive oxidation capacity, resulting in slow or even decreased carbon load growth. If regeneration is still triggered at a fixed cycle under these conditions, it constitutes unnecessary over-regeneration. This not only causes additional fuel consumption and increases operating costs but may also affect the DPF's lifespan and reduce vehicle uptime due to frequent high-temperature regeneration processes.

[0004] Essentially, existing technologies are unable to dynamically perceive and make intelligent decisions based on the actual operating conditions of the engine, and lack the fine-grained control capability for on-demand regeneration. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a dynamic correction control method, control unit, system, and diesel engine for DPF regeneration cycle. It introduces a dynamic correction factor based on carbon load and exhaust temperature to deduct from traditional fixed mileage and time trigger benchmarks in real time, thereby delaying the regeneration trigger point, reducing unnecessary regeneration operations, and ultimately lowering fuel consumption and operating costs.

[0006] In a first aspect, the present invention provides a dynamic correction control method for the regeneration cycle of a diesel particulate filter, comprising the following steps: S1. Real-time acquisition of engine operating parameters, including at least exhaust flow rate, current carbon load of DPF, exhaust temperature before DPF, and cumulative original operating mileage and cumulative original operating time since the last successful regeneration. S2. Based on the current engine operating condition parameters, when it is determined that the preset correction enabling conditions are met, the corresponding flow correction factor, carbon load correction factor and temperature correction factor are determined based on the exhaust flow rate, current carbon load and DPF pre-exhaust temperature, respectively. S3. Using the flow correction factor, carbon load correction factor and temperature correction factor, dynamically deduct and correct the cumulative original operating mileage and cumulative original operating time to obtain the corrected operating mileage and corrected operating time. S4. Regeneration is triggered if any of the following conditions are met: (a) The corrected running mileage exceeds the first set mileage threshold, or the corrected running time exceeds the first set time threshold; (b) The current carbon loading of the DPF exceeds the safe carbon loading threshold; Wherein, the first set mileage threshold is greater than the second set mileage threshold used to trigger regeneration when the dynamic deduction correction is not performed, and the first set time threshold is greater than the corresponding second set time threshold.

[0007] By dynamically deducting and correcting the accumulated original mileage and time, and setting differentiated regeneration trigger thresholds, the regeneration cycle is reasonably extended, unnecessary active regeneration operations are reduced, and fuel consumption and operating costs are lowered. At the same time, the mandatory triggering conditions of the carbon load safety threshold are retained. Under the premise of ensuring the safety of DPF operation, intelligent control of on-demand regeneration is realized, which solves the technical defects of the traditional fixed trigger strategy that is too conservative.

[0008] As a further limitation of the technical solution of the present invention, the preset modification enabling condition is that the engine is in a high-load operation mode; To determine whether to enter the high-load operation mode, the following conditions must be met simultaneously, and a stabilization time must be continuously set: (1) The exhaust temperature before the DPF remains higher than the first temperature threshold. (2) The engine speed remains above the speed threshold; (3) The engine load rate is consistently higher than the load rate threshold; If any of the conditions (1), (2), or (3) are no longer met, and a delay is continuously set, then the system is determined to exit the high-load operation mode.

[0009] Dynamic correction is activated only under high-load conditions most favorable for passive regeneration. This avoids misusing the correction strategy under conditions where passive regeneration is ineffective or inefficient, such as low exhaust temperature or low flow rate, preventing insufficient regeneration delay or DPF blockage due to incorrect correction. By setting a continuous stabilization time and a hysteresis logic with a set delay, the interference of instantaneous fluctuations in sensor signals on mode judgment is effectively filtered out, preventing frequent switching of control modes at high-load boundaries, making the entire control process smoother and more stable.

[0010] As a further limitation of the technical solution of the present invention, in S2, the flow correction factor, carbon loading correction factor and temperature correction factor are all obtained by querying the corresponding pre-calibration mapping table. The pre-calibrated mapping table is calibrated using engine bench tests and actual road test data. The calibration logic is to establish the correspondence between exhaust flow rate, DPF carbon load, DPF pre-exhaust temperature and DPF passive regeneration efficiency, and to normalize the correspondence into a correction factor with a value range of [0,1].

[0011] The precalibration mapping table includes: Exhaust flow rate - correction factor mapping table, in which the exhaust flow rate is divided into multiple continuous intervals, each interval corresponds to a flow correction factor value, and the larger the value of the interval in which the exhaust flow rate is located, the larger the corresponding flow correction factor value; The DPF carbon loading-correction factor mapping table divides the DPF carbon loading into multiple continuous intervals, each interval corresponding to a carbon loading correction factor value. The larger the interval value of the DPF carbon loading, the larger the corresponding carbon loading correction factor value. The DPF front exhaust temperature-correction factor mapping table divides the DPF front exhaust temperature into multiple continuous intervals, each interval corresponding to a temperature correction factor value. The larger the interval value of the DPF front exhaust temperature, the larger the corresponding temperature correction factor value.

[0012] By using a lookup table with a pre-calibrated mapping table, the nonlinear relationship between the three continuous variables—exhaust flow rate, carbon load, and temperature—and the complex passive regeneration process is transformed into a simple and fast lookup operation. This solves the problem of calculating passive regeneration efficiency online in real time, greatly reduces the computational burden on the controller, and enables the strategy to be efficiently deployed on existing engine control units (ECUs) without upgrading the hardware.

[0013] The mapping table is calibrated based on engine bench and actual road test data, ensuring that the correction factor truly reflects the efficiency characteristics of passive regeneration of a specific engine and vehicle in actual operation.

[0014] As a further limitation of the technical solution of the present invention, the dynamic deduction and correction of the cumulative original running mileage and cumulative original running time described in S3 is calculated iteratively using the following formula: Corrected mileage = Cumulative original mileage - (vehicle speed × time step × flow correction factor × carbon load correction factor × temperature correction factor); Corrected running time = Cumulative original running time - (Time step × Flow correction factor × Carbon loading correction factor × Temperature correction factor); The time step is a fixed calculation cycle for the controller to execute the dynamic correction control method.

[0015] Iterative calculations using time steps allow the correction process to closely follow continuous changes in engine operating conditions, enabling real-time deduction of mileage and time. This is more precise and results in faster control response compared to methods that perform one-time corrections based on fixed stages or mileage intervals.

[0016] As a further limitation of the technical solution of the present invention, the current carbon load of the DPF is calculated by obtaining the exhaust pressure difference measured by the differential pressure sensor set before and after the DPF, and combining it with the exhaust flow rate, through a pre-stored carbon load estimation model.

[0017] The study identified the use of differential pressure sensors combined with a model—a mature and reliable industry approach—to obtain the current carbon load of the DPF (Diverterless Power Factor). This provides accurate and crucial foundational data input for the entire dynamic correction strategy, ensuring the effectiveness and safety of the method. This approach eliminates the need to develop entirely new carbon load sensing technologies, directly utilizing existing vehicle sensors and mature estimation models. This lowers the implementation threshold and cost, facilitating rapid integration into existing vehicle platforms.

[0018] As a further limitation of the technical solution of the present invention, when the preset correction enabling condition is not met, if the cumulative original running mileage exceeds the second set mileage threshold, or the cumulative original running time exceeds the second set time threshold, then DPF regeneration is triggered.

[0019] It is clarified that when the dynamic correction conditions are not met, the system will automatically and seamlessly switch back to a conservative triggering strategy based on a fixed threshold. This fallback mechanism, together with the safe carbon load threshold, constitutes a double safety backup, ensuring that DPF regeneration triggering has clear and safe rules to follow under any operating condition.

[0020] In a second aspect, the present invention provides an engine control unit, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the dynamic correction control method for the regeneration cycle of the diesel particulate filter as described in the first aspect. The memory pre-stores exhaust flow-correction factor mapping table, DPF carbon load-correction factor mapping table, DPF inlet exhaust temperature-correction factor mapping table, as well as DPF carbon load estimation model, correction enable condition judgment parameter threshold and regeneration trigger threshold parameter; the processor can retrieve the corresponding data to complete correction factor query, carbon load calculation, correction enable judgment and regeneration trigger judgment.

[0021] By pre-storing various mapping tables, models, and threshold parameters in the memory, this control unit becomes a plug-and-play intelligent DPF control module, simplifying the vehicle integration process.

[0022] Thirdly, the present invention also provides a diesel engine aftertreatment control system, including a diesel particulate filter, a sensor assembly, and an engine control unit as described in the second aspect; the sensor assembly is electrically connected to the engine control unit and is used to transmit engine operating condition parameters to the engine control unit; the diesel particulate filter is signal connected to the engine control unit, receives a regeneration trigger command issued by the engine control unit, and performs a regeneration operation.

[0023] A complete aftertreatment control system architecture consisting of sensor components, engine control unit, and DPF was constructed. The sensor components provide comprehensive and real-time operating condition data to the control unit, which then performs correction and regeneration judgments based on the data and finally issues precise commands to the DPF, realizing closed-loop management of data acquisition, calculation control, and execution. This architecture can be directly integrated into existing diesel engine aftertreatment systems without significant hardware modifications, reducing the implementation cost of the technical solution.

[0024] Fourthly, the present invention also provides a diesel engine, including an engine body and a diesel engine aftertreatment control system as described in the third aspect, wherein the exhaust end of the engine body is connected to the DPF in the diesel engine aftertreatment control system, and the operating condition parameters of the engine body can be collected by sensor components and transmitted to the engine control unit.

[0025] By integrating the aftertreatment control system with the engine body, engine operating parameters can be seamlessly transmitted to the control unit, ensuring the timeliness and completeness of data acquisition. This achieves coordinated linkage between engine power output and DPF regeneration control, which not only does not affect the normal power performance of the engine, but also dynamically adjusts the DPF regeneration strategy according to the actual engine operating conditions, improving the overall economy and reliability of the diesel engine and extending the service life of the DPF and the engine.

[0026] As can be seen from the above technical solutions, this application has the following advantages: By introducing a comprehensive dynamic correction based on exhaust flow, carbon load, and exhaust temperature, the regeneration trigger point is extended only when the actual operating conditions of the vehicle permit. This effectively avoids unnecessary active regeneration under conditions with strong passive regeneration capabilities, thereby reducing the frequency of regeneration and directly reducing the additional fuel consumption and operating costs caused by active regeneration.

[0027] While implementing a dynamic correction strategy, independent safety triggering conditions based on actual carbon loading are retained. This constitutes a dual guarantee mechanism of dynamic optimization triggering and static safety fallback, ensuring that regeneration can be triggered immediately once the carbon loading exceeds the safety limit under any circumstances, fundamentally eliminating the risk of DPF damage due to overload.

[0028] By setting the first preset threshold higher than the second preset threshold and using it only when the correction enable is met, the system can adaptively adjust the triggering criteria according to different engine operating modes, resulting in more precise and reasonable control. Attached Figure Description

[0029] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A flowchart of a method provided in an embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the engine aftertreatment system architecture. Detailed Implementation

[0032] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0034] like Figure 1As shown, this embodiment of the invention provides a dynamic correction control method for the regeneration cycle of a diesel particulate filter, comprising the following steps: S1. Real-time acquisition of engine operating parameters, including at least exhaust flow rate, current carbon load of DPF, exhaust temperature before DPF, and cumulative original operating mileage and cumulative original operating time since the last successful regeneration. In this embodiment of the invention, the ECU collects data in real time through the vehicle sensor network, estimates the exhaust flow rate Q using an air flow meter, estimates the current carbon load S of the DPF using a differential pressure sensor before and after the DPF combined with a preset carbon load model; the carbon load model is a well-known existing technology in the field of diesel engine aftertreatment, and obtains the exhaust temperature T before the DPF using a temperature sensor before the DPF; and reads the cumulative original mileage since the last successful regeneration from the vehicle odometer and running timer. and cumulative original running time .

[0035] S2. Based on the current engine operating condition parameters, when it is determined that the preset correction enabling conditions are met, the corresponding flow rate correction factor, carbon load correction factor and temperature correction factor are determined based on the exhaust flow rate Q, the current carbon load S and the exhaust temperature T before the DPF. The ECU determines whether the current operating condition meets preset correction enabling conditions (e.g., whether the engine is in a high-speed, high-load operating condition). The preset correction enabling condition is that the engine is in a high-load operating mode; To determine whether to enter the high-load operation mode, the following conditions must be met simultaneously, and a stabilization time must be continuously set: (1) The exhaust temperature before the DPF is continuously higher than the first temperature threshold, which is 350°C in this embodiment of the invention; (2) The engine speed is continuously higher than the speed threshold of 1200 rpm; (3) The engine load rate is consistently higher than the load rate threshold, which is 60% in this case; If any of the conditions (1), (2), and (3) are no longer met, and a delay is continuously set (10 seconds in this embodiment of the invention), then the system is determined to exit the high-load operation mode.

[0036] If the conditions are met, dynamic correction is performed. The ECU has a pre-stored calibrated data table; based on the real-time collected Q, S, and T, the flow correction factor is obtained by looking up the table. Carbon loading correction factor Temperature correction factor These factors are coefficients that have been verified through bench and road tests and can reflect the influence of various parameters on passive regeneration efficiency. Their values ​​range from 0 to 1.

[0037] The flow correction factor, carbon loading correction factor, and temperature correction factor are all obtained by querying the corresponding pre-calibration mapping table; The pre-calibrated mapping table is calibrated using engine bench tests and actual road test data. The calibration logic establishes a correspondence between exhaust flow rate, DPF carbon load, DPF pre-exhaust temperature, and DPF passive regeneration efficiency, and normalizes this correspondence into a correction factor with a value in the range [0,1]. The specific calibration process is as follows: Phase 1: Basic Data Acquisition and Passive Regeneration Efficiency Characterization Step 1: Design a test matrix that covers all operating conditions.

[0038] On the engine test bench, the engine is controlled to operate at a series of steady-state operating points. Each operating point is defined by three key parameters: Exhaust flow rate Q: By adjusting engine speed and load, it covers the entire range from low idle to full load.

[0039] DPF front exhaust temperature T: The temperature is adjusted to cover the typical operating range by adjusting the fuel injection strategy, intake throttling, or external heating.

[0040] DPF initial carbon loading By supplying the engine with carbon soot generated under specific operating conditions, different masses of carbon soot are pre-loaded into the DPF.

[0041] Step 2: Perform passive regeneration test and data acquisition.

[0042] In each set (Q,T, Under the following operating conditions: Maintain stable operation under this condition for a predetermined period of time. In this embodiment of the invention, the time is set to 30 minutes.

[0043] Throughout During this period, the following parameters were collected and recorded at high frequency: exhaust flow rate Q, temperature before and after DPF, and pressure difference ΔP before and after DPF.

[0044] At the start of the test ( ) and end ( When using a precision balance weighing method or a precise inversion algorithm based on a pressure difference model, the actual carbon loading change within the DPF can be accurately measured. , A value greater than 0 indicates increased carbon buildup. <0 indicates that passive regeneration has occurred.

[0045] Step 3: Calculate the net passive regeneration efficiency coefficient at the operating point. .

[0046] For each test operating point, a dimensionless net passive regeneration efficiency coefficient is defined: when When it is negative, ,when When it is positive or zero, ; This represents the relative rate at which a unit of initial carbon loading is passively oxidized per unit time under a specific operating condition. A higher value indicates a greater contribution of that operating condition to delaying carbon loading accumulation.

[0047] Phase Two: Single-Parameter Impact Analysis and Mapping Table Construction Step 4: Data separation and univariate analysis.

[0048] The massive test dataset was organized using the controlled variable method: Construct an exhaust flow-efficiency dataset: fix a series of similar T values ​​and Analyze the average under different Q values Trends in change.

[0049] Constructing a carbon loading-efficiency dataset: Fixing a series of similar Q and T values, and analyzing different... The average below Trends in change.

[0050] Construct an exhaust temperature-efficiency dataset: fix a series of similar Q values ​​and Analyze the average values ​​under different T values. Trends in change.

[0051] Step 5: Normalization and correction factor assignment.

[0052] For each single-parameter dataset, find the one that makes The highest and lowest parameter values. This will maximize efficiency. The corresponding correction factor is set to 1.0, and the correction factor corresponding to the lowest efficiency is set to 0.

[0053] The entire range of values ​​for this parameter is divided into multiple consecutive intervals. The average value of all test points within each interval is then used as the basis for the calculation. The value is mapped to the [0,1] interval according to a linear or preset curve relationship to obtain the correction factor value of the parameter interval.

[0054] Example (exhaust temperature): Tests showed that when T < 300°C, Almost zero, therefore =0. When T≥450°C, the passive oxidation reaction is vigorous. The platform has reached its maximum value, therefore =1.0. Between 300°C and 450°C, As the temperature index increases, intervals are divided and assigned. The values ​​are 0.3, 0.5, 0.8, etc.

[0055] Example (carbon loading): Under the same Q and T, The higher the value, the more "reactants" participate in passive oxidation. The higher the (absolute oxidation rate), the better. It increases with increasing carbon loading. However, as it approaches the safety limit, other risks need to be considered, and the factor growth may slow down.

[0056] Example (exhaust flow rate): Increased flow rate usually results in higher oxygen concentration and mass transfer rate, which is beneficial for passive oxidation, therefore It increases with increasing flow rate.

[0057] Phase 3: Validation and Optimization Step 6: Road testing, verification, and fine-tuning.

[0058] The initial mapping table generated based on bench data was written into the mass-production ECU prototype and subjected to long-term real-world road testing on a real vehicle. By comparing the actual regeneration interval mileage / time, average fuel consumption, and DPF safety of vehicles using dynamic correction strategies and traditional fixed strategies, the factor values ​​in the mapping table were fine-tuned to ensure robustness and fuel economy under complex and variable operating conditions.

[0059] Step 7: Final calibration and curing.

[0060] After multiple rounds of bench and road testing, the final correction factor value was determined and stored together with the corresponding parameter range in three independent lookup tables. These tables were then burned into the non-volatile memory of the engine control unit for real-time querying by the online control program.

[0061] The precalibration mapping table includes: Exhaust flow rate - correction factor mapping table, in which the exhaust flow rate is divided into multiple continuous intervals, each interval corresponds to a flow correction factor value, and the larger the value of the interval in which the exhaust flow rate is located, the larger the corresponding flow correction factor value; Here, the exhaust flow rate is divided into ranges such as [<500, 500~800, 800~1000, 1000~1200, 1200~1500, ≥1500] kg / h, corresponding to... The values ​​are [0, 0.2, 0.3, 0.5, 0.6, 0.8]. The larger the flow, the larger the factor.

[0062] The DPF carbon loading-correction factor mapping table divides the DPF carbon loading into multiple continuous intervals, each interval corresponding to a carbon loading correction factor value. The larger the interval value of the DPF carbon loading, the larger the corresponding carbon loading correction factor value. The carbon loading was divided into intervals of [<5, 5~10, 10~15, 15~20, 20~25, ≥25] g, corresponding to... The values ​​are [0, 0.2, 0.3, 0.4, 0.6, 0.8]. The higher the carbon loading, the larger the factor, reflecting a stronger demand for passive regeneration.

[0063] The DPF front exhaust temperature-correction factor mapping table divides the DPF front exhaust temperature into multiple continuous intervals, each interval corresponding to a temperature correction factor value. The larger the interval value of the DPF front exhaust temperature, the larger the corresponding temperature correction factor value.

[0064] The exhaust temperature is divided into ranges of [<300, 300~350, 350~400, 400~450, ≥450] °C, corresponding to... The value is [0, 0.3, 0.5, 0.8, 1.0]. The higher the temperature, the larger the factor.

[0065] During implementation, the ECU determines the range in which the real-time collected Q, S, and T values ​​fall, and then calls upon the corresponding correction factor value. These mapping tables are obtained by normalizing the relationship between parameters and passive regeneration efficiency based on extensive experiments.

[0066] S3. Using the flow correction factor, carbon load correction factor and temperature correction factor, dynamically deduct and correct the cumulative original operating mileage and cumulative original operating time to obtain the corrected operating mileage and corrected operating time. The ECU uses the obtained correction factor to subtract from the original cumulative value. For example, at a time step... The correction value is calculated using the following formula: Corrected mileage

[0067] Corrected runtime

[0068] Under conditions of high passive regeneration efficiency (large K value), the system assumes that the actual carbon deposit growth of the DPF is slow, and therefore deducts a portion from the accumulated mileage and time, thereby delaying the triggering of regeneration.

[0069] S4 and ECU check two conditions in parallel: Condition (a) The corrected running mileage exceeds the first set mileage threshold, or the corrected running time exceeds the first set time threshold; Has the first set mileage threshold been exceeded? Does it exceed a first set time threshold (e.g., 240 hours)? This threshold is higher than the traditional fixed trigger threshold.

[0070] Condition (b) Whether the estimated current carbon loading S of the DPF exceeds the safe carbon loading threshold; If either condition (a) or condition (b) is met, the ECU immediately sends a command to the DPF aftertreatment system to trigger the active regeneration process. If neither condition is met, the process returns to S1 to continue the loop.

[0071] In this embodiment of the invention, the dynamic deduction and correction of the cumulative original mileage and cumulative original running time described in S3 is calculated iteratively using the following formula: Corrected mileage = Cumulative original mileage - (vehicle speed × time step × flow correction factor × carbon load correction factor × temperature correction factor); Corrected running time = Cumulative original running time - (Time step × Flow correction factor × Carbon loading correction factor × Temperature correction factor); The time step is a fixed calculation cycle for the controller to execute the dynamic correction control method.

[0072] It should be noted that the logic of dynamic deduction correction is: the product of flow correction factor, carbon loading correction factor and temperature correction factor, which represents the comprehensive passive regeneration efficiency coefficient of DPF under the current operating conditions. When the overall passive regeneration efficiency coefficient is larger, the amount deducted from the cumulative original running mileage and cumulative original running time in each time step is also larger, which makes the corrected running mileage and corrected running time grow more slowly compared with the cumulative original value, thereby delaying the time point when the first set mileage threshold and the first set time threshold are reached. Conversely, the smaller the overall passive regeneration efficiency coefficient, the smaller the amount deducted, and the earlier the regeneration will be triggered.

[0073] In this embodiment of the invention, the current carbon load of the DPF is calculated by obtaining the exhaust pressure difference measured by the differential pressure sensor set before and after the DPF, and combining it with the exhaust flow rate, using a pre-stored carbon load estimation model.

[0074] Carbon loading estimation model:

[0075] In the formula, This represents the current carbon loading of the DPF. The exhaust pressure difference is measured in real time by pressure sensors placed before and after the DPF. This is the baseline differential pressure for a clean DPF, a baseline value mapping table calibrated at different exhaust flow rates and temperatures after the DPF has been fully regenerated. Real-time exhaust flow rate is typically calculated using engine intake air flow rate and fuel injection quantity. For real-time exhaust temperature, the average of the DPF inlet temperature or the temperatures before and after the exhaust is usually taken as the representative temperature. , These are temperature-dependent model coefficients, obtained through engine bench testing, reflecting the influence of temperature-dependent physical properties such as exhaust viscosity and density on flow resistance. They are typically stored as temperature-dependent coefficients. Relevant table lookup. The flow rate index is a calibrated constant that reflects the nonlinear relationship between pressure difference and flow rate.

[0076] The engine control unit's memory contains a pre-calibrated clean DPF differential pressure mapping table. Model coefficient mapping table , .

[0077] The ECU performs the following operations in each operating cycle: Real-time sensor signal acquisition: DPF inlet pressure DPF post-pressure Exhaust flow rate Exhaust temperature .

[0078] Calculate the measured pressure difference: .

[0079] According to the current and Look up the table to get the corresponding and coefficients A , B .

[0080] Substituting the above values ​​into the formula, we obtain the current estimated carbon loading.

[0081] If the preset correction enable condition is not met, and the cumulative original running mileage exceeds the second preset mileage threshold, or the cumulative original running time exceeds the second preset time threshold, then DPF regeneration is triggered.

[0082] The ECU reads the differential pressure sensor signal and, combined with the current exhaust flow rate Q, estimates S=18g in real time using a pre-stored differential pressure-flow-carbon load model.

[0083] Enable judgment: Determines whether the current mode is not in high load mode.

[0084] Dynamic correction is disabled because the correction enable conditions are not met. At this time, the mileage / time used to trigger the comparison is directly equal to the accumulated original mileage / time. The ECU compares this to a second set mileage / time threshold and then to a safe carbon load threshold (40 grams).

[0085] Triggering criteria: Regeneration is triggered if the initial mileage exceeds 5000 kilometers or the initial time exceeds 200 hours; simultaneously, regeneration is also triggered immediately if the carbon loading S exceeds 40 grams. Otherwise, it is not triggered.

[0086] This invention also provides an engine control unit, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the dynamic correction control method for the regeneration cycle of the diesel particulate filter as described in the above embodiments. The memory pre-stores exhaust flow-correction factor mapping table, DPF carbon load-correction factor mapping table, DPF inlet exhaust temperature-correction factor mapping table, as well as DPF carbon load estimation model, correction enable condition judgment parameter threshold and regeneration trigger threshold parameter; the processor can retrieve the corresponding data to complete correction factor query, carbon load calculation, correction enable judgment and regeneration trigger judgment.

[0087] like Figure 2 As shown in the figure, this embodiment of the invention also provides a diesel engine aftertreatment control system, including a diesel particulate filter 30, a sensor assembly, and an engine control unit 50 as described in the above embodiment; the sensor assembly is electrically connected to the engine control unit and is used to transmit engine operating condition parameters to the engine control unit; the diesel particulate filter is signal connected to the engine control unit, receives regeneration trigger commands issued by the engine control unit, and performs regeneration operations.

[0088] It should be noted that the sensor assembly includes at least: a DPF differential pressure sensor 33 positioned before and after the diesel particulate filter 30, used to collect the exhaust pressure difference before and after the DPF; a DPF pre-exhaust temperature sensor 31, used to collect the exhaust temperature before the DPF; a DPF post-exhaust temperature sensor 32, used to collect the exhaust temperature after the DPF; an exhaust flow sensor, used to collect the engine exhaust flow; a vehicle speed sensor, used to collect the vehicle speed; an engine speed sensor, used to collect the engine speed; and a load rate detection module, used to detect the engine load rate. The DPF pre-exhaust temperature sensor 31 is located on the exhaust pipe 20 connecting the diesel engine 10 and the diesel particulate filter 30.

[0089] The exhaust pressure differential collected by the differential pressure sensor and the exhaust flow rate collected by the exhaust flow sensor can be retrieved by the engine control unit and substituted into the carbon load estimation model to calculate the current carbon load of the DPF.

[0090] After receiving the parameters, the ECU performs a series of calculations, including correction enable judgment, correction factor query, mileage-time correction, and regeneration trigger determination. When the ECU determines that the regeneration trigger conditions are met, it sends a regeneration trigger command to the DPF. After receiving the command, the DPF starts the active regeneration program, which oxidizes the carbon deposits in the filter body by increasing the exhaust temperature, thus completing the regeneration operation.

[0091] This invention also provides a diesel engine, including an engine body and a diesel engine aftertreatment control system as described in the above embodiments. The exhaust end of the engine body is connected to the DPF in the diesel engine aftertreatment control system. The operating parameters of the engine body can be collected by sensor components and transmitted to the engine control unit.

[0092] When the engine is under high load, the exhaust gas temperature and flow rate are high, and the DPF passive regeneration capability is strong. The ECU will activate a dynamic correction strategy to extend the regeneration cycle. When the engine enters a low load condition, the exhaust gas temperature decreases and the carbon buildup rate increases. The ECU switches to a conservative fixed threshold strategy to trigger regeneration in a timely manner, realizing the coordinated linkage between engine power output and DPF regeneration control, which not only ensures engine power performance but also extends the service life of the DPF.

[0093] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0094] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0095] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0096] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of dynamically modifying control of a diesel particulate filter regeneration cycle, characterized by, The method comprises the following steps: S1, acquiring in real time operating condition parameters of the engine, including at least exhaust flow, current carbon load of the DPF, exhaust temperature before the DPF, and cumulative original operating mileage and cumulative original operating time since the last successful regeneration; S2, when it is determined that the preset correction enabling condition is met according to the current engine operating condition parameters, determining a corresponding flow correction factor, carbon load correction factor and temperature correction factor based on the exhaust flow, current carbon load and exhaust temperature before the DPF; S3, using the flow correction factor, carbon load correction factor and temperature correction factor to dynamically deduct and correct the cumulative original operating mileage and cumulative original operating time to obtain corrected operating mileage and corrected operating time; S4, triggering regeneration when any of the following conditions is met: (a) the corrected operating mileage exceeds a first set mileage threshold, or the corrected operating time exceeds a first set time threshold; (b) the current carbon load of the DPF exceeds a safe carbon load threshold; wherein the first set mileage threshold is greater than a second set mileage threshold for triggering regeneration without the dynamic deduction correction, and the first set time threshold is greater than a corresponding second set time threshold.

2. The dynamic correction control method of a diesel particulate filter regeneration period according to claim 1, characterized by, The preset correction enabling condition is that the engine is in a high load operating mode; To determine that the high load operating mode is entered, the following conditions need to be met at the same time and last for a set stable time: (1) the exhaust temperature before the DPF continuously exceeds a first temperature threshold; (2) the engine speed continuously exceeds a speed threshold; (3) the engine load rate continuously exceeds a load rate threshold; When any of conditions (1), (2) and (3) is no longer met, and after a set delay time, it is determined that the high load operating mode is exited.

3. The dynamic correction control method of a diesel particulate filter regeneration period according to claim 1, characterized by, In S2, the flow correction factor, carbon load correction factor and temperature correction factor are obtained by querying corresponding pre-calibration mapping tables; wherein the pre-calibration mapping tables are calibrated by engine bench test and actual road test data, and the calibration logic is to establish the corresponding relationship between exhaust flow, DPF carbon load, exhaust temperature before the DPF and DPF passive regeneration efficiency, and normalize the corresponding relationship into correction factors with a value range in the interval [0, 1].

4. The dynamic correction control method of a diesel particulate filter regeneration period according to claim 3, characterized by, The pre-calibration mapping tables comprise: an exhaust flow-correction factor mapping table, wherein the exhaust flow is divided into multiple continuous intervals, each interval corresponds to a flow correction factor value, and the greater the interval value of the exhaust flow, the greater the corresponding flow correction factor value; a DPF carbon load-correction factor mapping table, wherein the DPF carbon load is divided into multiple continuous intervals, each interval corresponds to a carbon load correction factor value, and the greater the interval value of the DPF carbon load, the greater the corresponding carbon load correction factor value; a DPF exhaust temperature before the DPF-correction factor mapping table, wherein the exhaust temperature before the DPF is divided into multiple continuous intervals, each interval corresponds to a temperature correction factor value, and the greater the interval value of the exhaust temperature before the DPF, the greater the corresponding temperature correction factor value.

5. The dynamic correction control method of a diesel particulate filter regeneration period according to claim 4, characterized by, The dynamic deduction correction of the cumulative original running mileage and the cumulative original running time in S3 is iteratively calculated by the following formula: Corrected running mileage = cumulative original running mileage - (vehicle speed × time step × flow correction factor × carbon load correction factor × temperature correction factor); Corrected running time = cumulative original running time - (time step × flow correction factor × carbon load correction factor × temperature correction factor); The time step is a fixed operation period of the controller for executing the dynamic correction control method.

6. The method of claim 1, wherein The current carbon load of the DPF is calculated by obtaining the exhaust pressure difference measured by the pressure difference sensors arranged before and after the DPF, and combining the exhaust flow, through a pre-stored carbon load estimation model.

7. The dynamic correction control method of a diesel particulate filter regeneration period according to claim 1, characterized by, When the preset correction enabling condition is not met, if the cumulative original running mileage exceeds the second set mileage threshold or the cumulative original running time exceeds the second set time threshold, DPF regeneration is triggered.

8. An engine control unit, characterized by The memory stores a computer program, and the processor implements the dynamic correction control method of the DPF regeneration cycle according to any one of claims 1-7 when executing the computer program. The memory pre-stores an exhaust flow-correction factor mapping table, a DPF carbon load-correction factor mapping table, a DPF pre-exhaust temperature-correction factor mapping table, a DPF carbon load estimation model, correction enabling condition judgment parameter thresholds, and regeneration trigger threshold parameters. The processor can retrieve corresponding data to complete correction factor query, carbon load calculation, correction enabling judgment, and regeneration trigger judgment.

9. A diesel engine aftertreatment control system characterized by, The engine control unit according to claim 8; the sensor assembly is electrically connected with the engine control unit, for transmitting engine operating condition parameters to the engine control unit; the DPF is signal connected with the engine control unit, receives the regeneration trigger instruction issued by the engine control unit and performs the regeneration operation.

10. A diesel engine characterized by comprising: The diesel engine aftertreatment control system according to claim 9; the exhaust end of the engine body is communicated with the DPF in the diesel engine aftertreatment control system, and the operating condition parameters of the engine body can be collected by the sensor assembly and transmitted to the engine control unit.

Images