DDDPF regeneration control method and system based on differential pressure sensor and program product

Abstract

The invention relates to a DDPF regeneration control method, system and program product based on a differential pressure transducer, when a vehicle is in a parking regeneration control state, an engine is controlled to increase the idle speed, and when the upstream temperature of the DDPF exceeds an ignition temperature limit value, the vehicle enters the parking regeneration state; during regeneration, the amount of fuel injected into the engine is determined according to the DDPF upstream temperature, the set temperature target value and the waste gas amount, and engine rear injection is controlled for DDPF regeneration; according to the method, the pressure difference between an inlet and an outlet of the DDPF is obtained, the peak pressure difference P of the DDPF is determined when the regeneration state continues till the pressure difference begins to drop, and the fuel injection quantity is corrected or a prompt signal is sent out according to the size relation between the P and a set limiting value. A temperature sensor at the rear end of the DDPF is omitted, the characteristic that the pressure difference is increased and then reduced due to oxidation heat release of carbon particles and hydrocarbon during regeneration is utilized, regeneration control is achieved based on a pressure difference sensor, and the risk of local overheating damage is dealt with by comparing a pressure difference peak value with a set limiting value.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, specifically to a DDPF regeneration control method, system, and program product based on a differential pressure sensor. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In engine exhaust systems, DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter) are generally used for exhaust gas treatment. DOC uses a catalyst to lower the activation energy of chemical reactions of substances such as HC, CO, and SOF in engine exhaust, allowing these substances to undergo oxidation reactions at lower temperatures to produce harmless CO2 and H2O. DPF, on the other hand, filters and captures particulates in engine exhaust through diffusion, deposition, and impact mechanisms.

[0004] To reduce the size and cost of DOC / DPF systems, some non-road agricultural machinery (such as agricultural machinery and construction machinery) uses DDPF, or integrated oxidation trap, for exhaust gas treatment. DDPF is an aftertreatment technology that integrates the functions of DOC (diesel oxidation catalyst) and DPF (diesel particulate filter) onto a single carrier. By coating different catalyst formulations in different areas, it achieves oxidation catalysis and particulate matter capture in exhaust gases.

[0005] Both DOC+DPF and DDPF require regeneration. This is achieved by increasing the temperature to burn the deposited carbon particles, thereby restoring the DPF's deposition capacity. Current technologies typically control regeneration by monitoring the intake and exhaust temperatures of the exhaust gas treatment system. However, because DDPF integrates the DOC coating with the DPF, the heat released during regeneration is concentrated at the front end of the DPF, which can easily lead to uneven temperature distribution and localized overheating, damaging the carrier. Summary of the Invention

[0006] To address the technical problems mentioned above, this invention provides a DDPF regeneration control method, system, and program product based on a differential pressure sensor. It eliminates the temperature sensor at the back end of the DDPF and utilizes the characteristic that the differential pressure first increases and then decreases during regeneration due to the exothermic oxidation of carbon particles and hydrocarbons. Regeneration control is achieved based on the differential pressure sensor, and the risk of local overheating damage is mitigated by comparing the peak differential pressure with a set limit.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a DDPF regeneration control method based on a differential pressure sensor, comprising the following steps: When the vehicle is in the parking regeneration control state, the engine is controlled to increase the idle speed, and the temperature upstream of the DDPF is obtained. When it exceeds the ignition temperature limit, it enters the parking regeneration state; During regeneration, according to the temperature upstream of the DDPF, the set temperature target value, and the exhaust gas volume, the fuel quantity injected into the engine is determined, and the engine post-injection is controlled to perform DDPF regeneration; During regeneration, the pressure difference between the inlet and outlet of the DDPF is obtained. When the regeneration state continues until the pressure difference begins to decrease, the peak pressure difference △P of the DDPF is determined; When △P > A3, while maintaining the regeneration state, the fuel injection quantity is negatively corrected according to |△P - A3|; When A2 ≤ △Pd ≤ A3, the regeneration state is maintained; When △P < A2, while maintaining the regeneration state, the fuel injection quantity is positively corrected according to |△P - A2|; When △P < A1, the regeneration state is exited, and a prompt signal of "DDPF failure" is issued; Among them, A1, A2, and A3 are respectively the set first, second, and third limit values, and A1 < A2.

[0008] Furthermore, when the vehicle is in the set conditions and the carbon loading exceeds the parking regeneration limit, a parking regeneration request is triggered. After accepting the parking regeneration request, it enters the parking regeneration control state; where the set conditions are: the clutch is not engaged; the gear is in neutral; the vehicle speed is 0; the throttle pedal opening is 0; the service brake pedal opening is 0; the vehicle is in the parking brake state; the regeneration prohibition switch is not triggered; there is no system fault prohibiting regeneration.

[0009] Furthermore, according to the temperature upstream of the DDPF, the set temperature target value, and the exhaust gas volume, the feedforward fuel quantity during parking regeneration is determined; specifically: the difference between the temperature upstream of the DDPF and the temperature target value is determined, the heat to be supplemented is determined by combining the exhaust gas volume and the specific heat capacity of the exhaust gas, and the feedforward fuel quantity is determined based on the fuel calorific value and combustion efficiency.

[0010] Furthermore, according to the set temperature target value and the pre-calibrated DDPF model temperature, the closed-loop fuel quantity during parking regeneration is obtained; specifically: the difference between the DDPF model temperature and the temperature target value is determined, and the closed-loop fuel quantity is obtained according to the difference in combination with the corresponding coefficient; where the DDPF model temperature is determined by pre-calibration and is used to reflect the temperature that should be reached downstream of the DDPF under different engine states.

[0011] Furthermore, controlling the engine post-injection to perform DDPF regeneration, specifically: injecting fuel during the expansion stroke of the engine, and the exhaust gas containing fuel is burned by high-temperature oxidation in the DDPF to achieve the regeneration of the DDPF.

[0012] Furthermore, during regeneration, when the DDPF carbon loading is less than a set limit, the regeneration process ends.

[0013] A second aspect of the present invention provides a DDPF regeneration control system based on a differential pressure sensor, comprising: The status control module is configured to: when the vehicle is in the parking regeneration control state, control the engine to increase the idle speed and obtain the upstream temperature of DDPF; when the temperature exceeds the ignition temperature limit, enter the parking regeneration state. The fuel quantity calculation module is configured to: during regeneration, determine the amount of fuel injected into the engine based on the upstream temperature of DDPF, the set temperature target value, and the exhaust gas volume, and control the engine to perform DDPF regeneration via post-injection. The fuel quantity control module is configured to: during regeneration, acquire the pressure difference between the DDPF inlet and outlet; when the regeneration state continues until the pressure difference begins to decrease, determine the peak pressure difference ΔP of the DDPF; and adjust the fuel injection quantity or issue a warning signal based on the relationship between ΔP and the set limit.

[0014] A third aspect of the present invention provides a computer program product including computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the above-described DDPF regeneration control method based on a differential pressure sensor.

[0015] A fourth aspect of the present invention provides an electronic device including at least one processor and a memory connected to the processor, the memory being used to store a computer program; the processor being used to execute the computer program, enabling the electronic device to implement the above-described DDPF regeneration control method based on a differential pressure sensor.

[0016] A fifth aspect of the present invention provides a computer storage medium carrying one or more computer programs that, when executed by an electronic device, enable the electronic device to implement the above-described DDPF regeneration control method based on a differential pressure sensor.

[0017] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects: 1. DDPF divides the carrier portion of DPF into two sections, coating each section with a different catalyst to achieve the functions of both DOC and DPF. The localized overheating problem in existing technologies is caused by the rapid exothermic characteristics of the DOC section. This rapid exothermic effect makes the exhaust temperature more uniform after passing through DDPF, resulting in smaller temperature fluctuations at the downstream end and reducing its necessity. Therefore, this solution eliminates the temperature sensor at the downstream end of DDPF, no longer collecting downstream temperature data. Regeneration control can be achieved using a pre-calibrated model temperature combined with exhaust gas volume and upstream temperature, reducing hardware costs and maintenance requirements. This addresses the limitations of maintenance conditions and cost sensitivity in non-road agricultural machinery.

[0018] 2. During regeneration, the oxidation of carbon particles and hydrocarbons is exothermic, causing the differential pressure of DDPF to first increase and then decrease. This characteristic can be monitored by a differential pressure sensor, enabling this scheme to achieve regeneration control using a differential pressure sensor.

[0019] 3. During regeneration control, the differential pressure peak value obtained from the differential pressure sensor is used in conjunction with multiple pre-calibrated limits for regeneration control, so that the differential pressure peak value is maintained between the limits A2 and A3. When the differential pressure peak value exceeds the third limit A3, there is a risk of overheating, and the fuel injection quantity needs to be reduced; when it is lower than the second limit A2, there is a risk of insufficient temperature, and the fuel injection quantity needs to be increased; when the differential pressure peak value is too low (below the first limit A1), the DDPF may fail, so parking regeneration is prohibited and a corresponding warning is given to ensure the safety of the system and avoid damage to the DDPF. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a schematic diagram of the DDPF system provided in one or more embodiments of the present invention; Figure 2 This is a schematic diagram of the overall process of DDPF regeneration control based on a differential pressure sensor provided in one or more embodiments of the present invention; Figure 3 This is a schematic diagram of the DDPF regeneration control process during parking provided in one or more embodiments of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the scope of exemplary embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] Terminology Explanation: DPF: Diesel Particulate Filter, used to capture particulate matter in exhaust gas. When the mass of captured particulate matter reaches a certain level, passive or active regeneration is required to restore the DPF's ability to capture particulate matter.

[0026] DOC: Diesel Oxide Catalyst, installed before the DPF, is used to oxidize NO in the exhaust gas to NO2, while increasing the exhaust gas temperature and assisting the normal operation of the DPF and SCR.

[0027] SCR, or Selective Catalytic Reduction system, uses a catalyst to inject a reducing agent (NH3) into the processor, reducing NO and NO2 to N2. The reducing agent NH3 is typically urea, stored in liquid form in a container.

[0028] Particulate matter, the particulate matter contained in engine exhaust, generally includes two components: soot and ash. Soot refers to the part that can be burned off through regeneration, while ash refers to the non-combustible component, which will continue to accumulate in the DPF. When it reaches a certain accumulation amount, it needs to be removed and cleaned. Most of the material in particulate matter is combustible, so the DPF's packing capacity can be restored through regeneration, that is, the carbon load can be restored.

[0029] Diesel oxidation catalysis (DOC) involves coating a honeycomb ceramic support with a noble metal catalyst (such as Pt). Its purpose is to lower the activation energy of chemical reactions involving HC, CO, and SOF in engine exhaust, allowing these substances to undergo oxidation reactions with oxygen in the exhaust at lower temperatures, ultimately converting them into CO2 and H2O. Oxidation catalytic converters do not require regeneration systems or control devices, and are characterized by their simple structure and high reliability; they have already found some application in modern small engines.

[0030] Diesel Particulate Filter (DPF) technology primarily filters and captures particulate matter in engine exhaust through diffusion, deposition, and impaction mechanisms. As exhaust flows through the filter, particulate matter is captured within the filter element, leaving cleaner exhaust gas to be released into the atmosphere. Currently, wall-flow honeycomb ceramic filters are widely used, mainly in construction machinery and city buses. They are characterized by simple operation and high filtration efficiency, but suffer from issues such as filter regeneration and sensitivity to sulfur in fuel.

[0031] The basic working principle of a particulate matter trap system is as follows: When engine exhaust flows through an oxidation catalyst (DOC), at temperatures of 200-600℃, CO and HC are almost entirely oxidized into CO2 and H2O, while NO is converted into NO2. After exiting the DOC, the exhaust enters the particulate filter (DPF), where the particulates are captured within the filter element, leaving the cleaner exhaust to be released into the atmosphere. The DPF's capture efficiency can reach over 90%.

[0032] NO2 has a strong oxidizing ability on the captured particles. The generated NO2 is used as an oxidant to remove particles from the particulate trap and generate CO2. The NO2 is then reduced to NO, thereby achieving the purpose of removing particles.

[0033] DOC internal reaction principle:

[0034] DPF internal reaction principle: .

[0035] DDPF: An integrated oxidation trap that combines the functions of both DOC-formulated and DPF-formulated catalysts.

[0036] DDPF principle diagram Figure 1 As shown, T4 is the DDPF device. Carbon soot, NOx, and fuel emitted from the engine are input into the DDPF inlet, enabling the capture of carbon soot and the oxidation of fuel to raise its temperature. T1 is a temperature sensor, T2 is a differential pressure sensor across the DDPF, and T3 is the model-calculated temperature.

[0037] Example 1: Both DOC+DPF and DDPF require regeneration, which can be divided into two methods: active regeneration and passive regeneration. Active regeneration refers to using external energy to increase the temperature inside the trap, causing the particulate matter to ignite and burn. When the temperature in the filter reaches 550 °C, the deposited particulate matter will oxidize and burn. If the temperature does not reach 550 °C, excessive deposits will clog the filter. At this time, an external energy source (such as an electric heater, a burner, or a change in engine operating conditions) needs to be used to increase the temperature inside the DPF, causing the particulate matter to oxidize and burn.

[0038] Passive regeneration refers to using fuel additives or catalysts to lower the ignition temperature of the particulate matter, enabling the particulate matter to ignite and burn at normal engine exhaust temperatures. Additives (such as cerium, iron, and strontium) need to be added to the fuel in a certain proportion. Excessive additives have little impact, but if too little is added, it will cause regeneration delay or an increase in the regeneration temperature.

[0039] Due to the limitations of the internal structural space of non-road agricultural machinery, it is difficult to adopt the traditional DOC + DPF solution. At the same time, the operating environment of non-road agricultural machinery is often in remote areas with poor maintenance conditions. Therefore, considering limited space and complex operating conditions, non-road agricultural machinery selects DDPF to meet strict emission regulations at the lowest cost while ensuring reliability and maintenance-free performance.

[0040] Therefore, considering that non-road agricultural machinery is often in low-speed, high-torque operating conditions with relatively low exhaust temperatures (200 - 400 °C), which is not conducive to passive regeneration, this solution selects the active regeneration method.

[0041] As Figure 2 shown, the DDPF regeneration control method based on a differential pressure sensor includes the following steps: When the vehicle is in the parked regeneration control state, control the engine to increase the idle speed and obtain the upstream temperature of the DDPF. When it exceeds the ignition temperature limit, determine the feedforward fuel quantity during parked regeneration according to the exhaust gas volume and the set temperature target value; obtain the closed-loop fuel quantity during parked regeneration according to the set temperature target value and the pre-calibrated DDPF model temperature; Use the sum of the feedforward fuel quantity and the closed-loop fuel quantity as the final fuel quantity, and control the engine to perform post-injection for DDPF regeneration; During regeneration, obtain the differential pressure between the inlet and outlet of the DDPF. When the regeneration state continues until the differential pressure starts to decrease, determine the peak differential pressure △P of the DDPF; When △P > A3, there is a risk of overheating. While maintaining the regeneration state, perform negative correction on the feedforward fuel quantity according to |△P - A3|; When A2 ≤ △Pd ≤ A3, maintain the regeneration state; When △P < A2, the regeneration temperature is insufficient. While maintaining the regeneration state, perform positive correction on the feedforward fuel quantity according to |△P - A2|; When △P < A1, exit the regeneration state and issue a prompt signal of "DDPF failure". Where A1, A2, and A3 are the first, second, and third limit values respectively, and A1 < A2.

[0042] When the vehicle state meets the following set conditions, execute the regeneration control process of this solution.

[0043] The set conditions are: the clutch is not depressed; the gear is in neutral; the vehicle speed is 0; the throttle pedal opening is 0; the service brake pedal opening is 0; in the parking brake state; the regeneration prohibition switch is not pressed; there is no system fault prohibiting regeneration.

[0044] When the vehicle is powered on, when all the above set conditions are met and the carbon loading exceeds the parking regeneration limit value, trigger a parking regeneration request, the regeneration indicator light flashes, and press the parking regeneration switch to enter the parking regeneration control state.

[0045] The parking regeneration control state is as Figure 3 shown, the engine raises the idle speed and warms up under the control of the thermal management system.

[0046] When the DDPF upstream temperature exceeds the ignition temperature limit value, enter the parking regeneration state; if it does not exceed the ignition temperature limit value, return to the previous step to continue warming up.

[0047] Parking regeneration state: Calculate the feedforward injection quantity for parking regeneration according to the DDPF upstream temperature, set temperature, and exhaust gas volume. Take the DDPF downstream temperature target value as the set value, and use the DDPF model temperature as the feedback value for closed-loop control to obtain the closed-loop fuel quantity. The sum of the feedforward fuel quantity and the closed-loop fuel quantity is used as the final control fuel quantity, and soot is regenerated through post-injection of the engine in a high-temperature and O2 environment.

[0048] In this embodiment, calculate the feedforward injection quantity for parking regeneration according to the DDPF upstream temperature, set temperature, and exhaust gas volume. Specifically: Based on the temperature sensor, obtain the actual DDPF upstream temperature (T_actual), such as Figure 1 "T1" in The set temperature is used as the regeneration target temperature (T_target), that is, the target value of the DDPF downstream temperature, for example, set at 550 - 650 °C; Obtain the exhaust gas flow rate (Q_exhaust); The heat to be supplemented ΔQ = C_p × (T_target - T_actual) × Q_exhaust; where C_p is the specific heat capacity of the exhaust gas, obtained through calibration; The feedforward fuel injection quantity Q_feedforward = ΔQ / (H_fuel × η), where H_fuel is the calorific value of the fuel and η is the combustion efficiency.

[0049] In this implementation, the "target value of downstream temperature of DDPF" is the temperature required to achieve regeneration. It is a set value determined based on actual needs. Based on the difference between this set value and the actual upstream temperature of DDPF, the heat gap to trigger regeneration is determined. Then, based on the combustion efficiency and fuel calorific value, it is converted into fuel quantity, thereby obtaining the feedforward fuel quantity.

[0050] In this embodiment, the downstream temperature of the DDPF is used as the setpoint, and the DDPF model temperature is used as the feedback value for closed-loop control to obtain the closed-loop oil quantity. Taking PID control as an example, specifically: Obtain the error signal: e(t) = T_target - T_model; T_model is the DDPF model temperature, which takes into account factors such as airflow and soot load, i.e., the pre-calibrated DDPF outlet temperature; The closed-loop oil quantity Q_feedback is output based on the error signal: Q_feedback = K_p × e(t) + K_i∫e(t)dt + K_d × de(t) / dt, where K_p, K_i, and K_d are all coefficients that need to be calibrated and optimized to prevent overshoot or oscillation.

[0051] In this implementation, the "target value of DDPF downstream temperature" is the temperature required for regeneration, and is a set value determined based on actual needs. The "DDPF model temperature," as the feedback value, is... Figure 1 In the T3 model, because the DDPF outlet temperature sensor is removed, the outlet temperature cannot be directly obtained. Therefore, the outlet temperature is calibrated through prior experiments or simulations to obtain the temperature that the DDPF outlet should reach during regeneration under theoretical or experimental conditions, i.e., the "DDPF model temperature". The injection quantity is determined by calculating the error between the "temperature required to achieve regeneration" and the "temperature that the DDPF outlet should reach during regeneration". This injection quantity is determined based on the temperature difference and is used to correct the feedforward injection quantity, hence it is called the closed-loop injection quantity.

[0052] The sum of the feedforward fuel injection quantity Q_feedforward and the closed-loop fuel quantity Q_feedback is used as the final control fuel quantity. The engine uses the final control fuel quantity as the control parameter and regenerates soot (combustible carbon particles) by reacting in a high-temperature and O2 environment through post-injection.

[0053] In this embodiment, the feedforward fuel quantity is calculated based on the theoretical heat gap. The required fuel quantity is directly estimated by using the difference between the current exhaust temperature (actual temperature upstream of the DDPF) and the target regeneration temperature, combined with the fuel's calorific value and combustion efficiency. This provides the base fuel quantity at the moment of regeneration triggering, avoiding delays in temperature rise. In the event of sudden changes in agricultural machinery load (such as a sudden increase in throttle in an excavator), the feedforward can immediately adjust the fuel injection quantity. The closed-loop fuel quantity, on the other hand, dynamically adjusts the fuel injection quantity (PID control) by monitoring the deviation between the expected temperature at the DDPF outlet and the calibrated target value. This corrects for factors not covered by the feedforward control and prevents localized overheating.

[0054] The "DDPF model temperature," used as feedback, is the temperature that the DDPF outlet should reach during regeneration, calibrated through prior experiments or simulations. It is not the actual temperature at the DDPF outlet. Omitting the outlet temperature sensor (such as a thermocouple) reduces cost and packaging complexity, making it particularly suitable for space-constrained and cost-sensitive off-road agricultural machinery. In modern engine control, calibrating parameters (such as MAP) based on prior experiments or simulations is a mature approach. Through extensive bench and vehicle calibration, the obtained "DDPF model temperature" covers most practical operating conditions and is sufficiently reliable under steady-state or slowly changing conditions.

[0055] In this embodiment, post-injection refers to adding fuel during the engine's expansion stroke, causing the fuel-laden exhaust gas to undergo high-temperature oxidation combustion in the DDPF of the exhaust gas treatment system, burning off the combustible portion (soot) in the carbon particles, thereby achieving DDPF regeneration.

[0056] During the parking regeneration phase, continuously monitor the relevant fault information of the differential pressure sensor and the differential pressure value of DDPF. If there is no relevant fault information of the differential pressure sensor and the differential pressure value of DDPF increases monotonically, proceed to the next step; if neither condition is met, return to the previous step.

[0057] When the engine is injected after the fuel injection begins, the timing starts and the peak pressure difference of DDPF is calculated. When the timing exceeds the set value and the DDPF pressure difference begins to decrease, the peak pressure difference of DDPF at this time, ΔP, is locked. The relationship between ΔP and the set limit is compared, and the corresponding command is triggered.

[0058] In this embodiment, the DDPF pressure difference begins to decrease. During the period of collecting DDPF pressure difference values ​​at set intervals, the pressure difference values ​​corresponding to two adjacent moments are continuously compared. If the pressure difference value at the current moment is greater than the pressure difference value at the previous moment, the collection continues. If the pressure difference value at the current moment is less than the pressure difference value at the previous moment, the "pressure difference value at the previous moment" is used as the peak DDPF pressure difference ΔP.

[0059] By comparing the magnitude of △P with the set limit, the corresponding instruction is triggered, specifically: When the peak differential pressure △P of DDPF exceeds the third limit value A3 (△P > A3), it is considered that there is a risk of overheating during regeneration. According to the absolute value of the deviation between △P and the third limit value A3, |△P - A3|, the feed fuel quantity is corrected negatively. When the peak differential pressure △P of DDPF is between the second limit value A2 and the third limit value A3 (A2 ≤ △Pd ≤ A3), it is considered that the exhaust gas treatment system is normal and the regeneration state is maintained. When the peak differential pressure △P of DDPF is less than the second limit value A2 (△P < A2), the regeneration temperature is insufficient. According to the absolute value of the deviation between △P and the limit value A2, |△P - A2|, the feed fuel quantity is corrected positively. During this period, when the carbon loading is less than a certain limit value, the parking regeneration is exited. During this period, when the peak differential pressure △P of DDPF is less than the first limit value A1 (the first limit value A1 is less than the second limit value A2), it is considered that the DDPF system fails, the regeneration state is exited, and corresponding special flash code reminders are given.

[0060] Analyzing the structural characteristics of DDPF, the carrier part of DPF is divided into two partitions in DDPF. By coating different catalysts on the two partitions, the functions of DOC and DPF are taken into account. This structure is too integrated. In the prior art, during regeneration, since the heat release of the DOC section is concentrated at the front end of the DPF carrier, it is easy to cause uneven temperature distribution, resulting in local overheating and damage to the carrier (the carrier is generally a honeycomb ceramic or a metal sintered product, and its own heat transfer performance is relatively weak). And this problem is caused by the fast heat release characteristic of the DOC section. The fast heat release makes the exhaust gas temperature tend to be uniform after passing through DDPF, and the temperature fluctuation at the rear end is small, so the necessity is reduced. Therefore, the temperature sensor at the rear of DDPF can be cancelled to reduce the hardware cost and maintenance requirements.

[0061] Secondly, during regeneration, due to the characteristic that the differential pressure first increases and then decreases due to the oxidation heat release of soot and HC, the differential pressure sensor is used to control the DDPF regeneration temperature. Aiming at the problem of local overheating damage of the temperature, by comparing the peak differential pressure of DDPF with the limit value, it is judged that there is a risk of overheating during parking regeneration, or the fuel quantity is insufficient, or the DDPF system fails, and then the parking regeneration is prohibited and corresponding special flash code reminders are given.

[0062] In summary, cancelling the temperature sensor at the rear of DDPF is the result of weighing cost and performance. The core is to reduce the hardware cost through system integration and control strategy simplification, sacrificing the redundancy of temperature monitoring and the fault diagnosis ability. However, for non-road agricultural machinery, due to its relatively fixed working conditions, therefore, cancelling the temperature sensor at the rear and using the differential pressure sensor配合相对更为保守的控制策略实现再生控制是可行的。

[0063] Example Two: It should be noted that there is an unclear expression in the original text "利用压差传感器配合相对更为保守的控制策略实现再生控制是可行的", and the translation is adjusted according to the context as much as possible. You can further clarify the specific requirements for this part if needed.The DDPF regeneration control system based on differential pressure sensors includes: The status control module is configured to: when the vehicle is in the parking regeneration control state, control the engine to increase the idle speed and obtain the upstream temperature of DDPF; when the temperature exceeds the ignition temperature limit, enter the parking regeneration state. The fuel quantity calculation module is configured to: during regeneration, determine the amount of fuel injected into the engine based on the upstream temperature of DDPF, the set temperature target value, and the exhaust gas volume, and control the engine to perform DDPF regeneration via post-injection. The fuel quantity control module is configured to: during regeneration, acquire the pressure difference between the DDPF inlet and outlet; when the regeneration state continues until the pressure difference begins to decrease, determine the peak pressure difference ΔP of the DDPF; and adjust the fuel injection quantity or issue a warning signal based on the relationship between ΔP and the set limit.

[0064] The temperature sensor at the back end of the DDPF was eliminated. During regeneration, the oxidation of carbon particles and hydrocarbons causes the differential pressure to rise and then fall. Regeneration control is achieved based on the differential pressure sensor, and the peak differential pressure is compared with the set limit to deal with the risk of local overheating damage.

[0065] Example 3: A computer program product includes computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the aforementioned DDPF regeneration control method based on a differential pressure sensor.

[0066] Example 4: An electronic device includes at least one processor and a memory connected to the processor, the memory storing a computer program; the processor executes the computer program, enabling the electronic device to implement the above-described DDPF regeneration control method based on a differential pressure sensor.

[0067] Example 5: A computer storage medium carrying one or more computer programs, which, when executed by an electronic device, enable the electronic device to implement the aforementioned DDPF regeneration control method based on a differential pressure sensor.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A DDPF regeneration control method based on a differential pressure sensor, characterized in that, It includes the following steps: When the vehicle is in the parking regeneration control state, control the engine to increase the idle speed, obtain the temperature upstream of the DDPF, and enter the parking regeneration state when the temperature exceeds the ignition temperature limit value; During regeneration, determine the fuel quantity injected into the engine according to the temperature upstream of the DDPF, the set temperature target value, and the exhaust gas quantity, and control the post-injection of the engine to perform DDPF regeneration; During regeneration, obtain the pressure difference between the inlet and outlet of the DDPF. When the regeneration state continues until the pressure difference begins to decrease, determine the peak pressure difference △P of the DDPF; correct the fuel injection quantity or issue a prompt signal according to the magnitude relationship between △P and the set limit value.

2. The DDPF regeneration control method based on a differential pressure sensor as described in claim 1, characterized in that, When the vehicle is in the set conditions and the carbon loading exceeds the parking regeneration limit value, trigger a parking regeneration request, accept the parking regeneration request, and enter the parking regeneration control state; wherein, the set conditions are: the clutch is not engaged; the gear is in neutral; the vehicle speed is 0; the throttle pedal opening is 0; the service brake pedal opening is 0; the vehicle is in the parking brake state; the regeneration prohibition switch is not triggered; there is no system fault prohibiting regeneration.

3. The DDPF regeneration control method based on a differential pressure sensor as described in claim 1, characterized in that, Determine the fuel quantity injected into the engine according to the temperature upstream of the DDPF, the set temperature target value, and the exhaust gas quantity, including determining the difference between the temperature upstream of the DDPF and the temperature target value, combining the exhaust gas quantity and the specific heat capacity of the exhaust gas to determine the heat to be supplemented, and determining the feedforward fuel quantity based on the fuel calorific value and combustion efficiency.

4. The DDPF regeneration control method based on a differential pressure sensor as described in claim 3, characterized in that, Determine the fuel quantity injected into the engine according to the temperature upstream of the DDPF, the set temperature target value, and the exhaust gas quantity, and also include determining the difference between the DDPF model temperature and the temperature target value, and obtaining the closed-loop fuel quantity according to the difference combined with the corresponding coefficient; wherein, the DDPF model temperature is determined by pre-calibration and is used to reflect the temperature that should be reached downstream of the DDPF under different engine states.

5. The DDPF regeneration control method based on a differential pressure sensor as described in claim 4, characterized in that, Determine the fuel quantity injected into the engine according to the temperature upstream of the DDPF, the set temperature target value, and the exhaust gas quantity, and also include using the sum of the feedforward fuel quantity and the closed-loop fuel quantity as the final fuel quantity injected into the engine, injecting fuel during the expansion stroke of the engine, and the exhaust gas containing fuel is oxidized and combusted at high temperature in the DDPF to achieve the regeneration of the DDPF.

6. The DDPF regeneration control method based on a differential pressure sensor as described in claim 1, characterized in that, Correct the fuel injection quantity or issue a prompt signal according to the magnitude relationship between △P and the set limit value, specifically: When △P > A3, while maintaining the regeneration state, negatively correct the fuel injection quantity according to |△P - A3|; When A2 ≤ △Pd ≤ A3, maintain the regeneration state; When △P < A2, while maintaining the regeneration state, positively correct the fuel injection quantity according to |△P - A2|; When △P < A1, exit the regeneration state and issue a prompt signal of "DDPF failure"; wherein, A1, A2, and A3 are respectively the set first, second, and third limit values, and A1 < A2.

7. The DDPF regeneration control method based on a differential pressure sensor as described in claim 1, characterized in that, During regeneration, when the DDPF carbon loading is less than the set limit value, exit the regeneration state.

8. A regeneration control system for implementing the method of any one of claims 1-7, characterized in that, It includes: A state control module configured to: when the vehicle is in the parking regeneration control state, control the engine to increase the idle speed, obtain the temperature upstream of the DDPF, and enter the parking regeneration state when the temperature exceeds the ignition temperature limit value; The fuel quantity calculation module is configured to: during regeneration, determine the amount of fuel injected into the engine based on the upstream temperature of DDPF, the set temperature target value, and the exhaust gas volume, and control the engine to perform DDPF regeneration via post-injection. The fuel quantity control module is configured to: during regeneration, acquire the pressure difference between the DDPF inlet and outlet; when the regeneration state continues until the pressure difference begins to decrease, determine the peak pressure difference ΔP of the DDPF; and adjust the fuel injection quantity or issue a warning signal based on the relationship between ΔP and the set limit.

9. A computer program product, characterized in that, Includes computer-readable instructions that, when executed on an electronic device, cause the electronic device to perform the steps in the DDPF regeneration control method based on a differential pressure sensor as described in any one of claims 1-7.

10. An electronic device, characterized in that, It includes at least one processor and a memory connected to the processor, the memory being used to store a computer program; the processor is used to execute the computer program, enabling the electronic device to perform the steps in the DDPF regeneration control method based on a differential pressure sensor as described in any one of claims 1-7.

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