Dpf regeneration function test system and regeneration test method thereof

Abstract

The present application relates to the technical field of vehicle control, and discloses a DPF regeneration function test system, which comprises an engine hardware-in-the-loop test system, contains a whole vehicle model and an engine model, further comprises a DOC model connected in series with the engine model and a DPF model connected in series with the DOC model, and forms a closed loop by collecting post-injection amount, simulating sending of a DOC inlet temperature message of the DOC model, a DOC outlet temperature message of the DOC model, a DPF outlet temperature message of the DPF model and a DPF differential pressure message of the DPF model to an ECU, so as to realize DPF regeneration function. The present application further discloses a regeneration test method of the DPF regeneration function test system. The DPF regeneration function test system and the regeneration test method thereof provide necessary conditions for DPF regeneration, can simulate DPF regeneration, are helpful for optimization of a DPF regeneration control algorithm, thereby improving regeneration efficiency, reducing fuel consumption, shortening development cycle and reducing cost.

Description

Technical Field

[0001] This invention relates to the field of engine exhaust gas treatment technology, and specifically to a DPF regeneration function testing system and its regeneration testing method. Background Technology

[0002] With the implementation of China VI emission standards and future upgrades, the requirements for particulate matter emissions from diesel engines are becoming increasingly stringent. Currently, diesel particulate filters (DPFs) are widely used in China VI diesel engine platforms from various manufacturers. A DPF is a ceramic filter installed in the engine's emission system to capture particulate matter in the exhaust before it enters the atmosphere. Over time, more and more particulate matter accumulates on the DPF, affecting its filtration efficiency and increasing exhaust back pressure. This, in turn, affects engine ventilation and combustion, leading to reduced power output and increased fuel consumption. Therefore, timely removal of particulate matter from the DPF (DPF regeneration) is crucial to this technology. DPF regeneration refers to the process where, during long-term operation, the gradual increase in particulate matter in the filter causes increased engine back pressure, leading to decreased engine performance. Therefore, it is necessary to periodically remove the deposited particulate matter to restore the DPF's filtration performance.

[0003] Since DPF regeneration functionality is typically validated on an engine bench or in a real vehicle, it has the following drawbacks:

[0004] 1. Regeneration can only be performed when conditions such as carbon load are met during testing, and the working conditions on the test bench or in a real vehicle are not easily adjusted.

[0005] 2. The exhaust temperature rises slowly and may be temporarily interrupted, requiring restarting, which takes a long time.

[0006] 3. The heating process requires a large amount of fuel, resulting in fuel waste. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of the aforementioned technologies by providing a DPF regeneration function testing system and its regeneration testing method. This system provides the necessary conditions for DPF regeneration and can simulate DPF regeneration, which helps optimize the DPF regeneration control algorithm, thereby improving regeneration efficiency, reducing fuel consumption, shortening the development cycle, and lowering costs.

[0008] To achieve the above objectives, the DPF regeneration function test system designed in this invention includes an engine hardware-in-the-loop test system, comprising a vehicle model and an engine model, as well as a DOC model connected in series with the engine model and a DPF model connected in series with the DOC model. By collecting the post-injection fuel quantity, the system simulates and sends the DOC inlet temperature message, the DOC outlet temperature message, the DPF outlet temperature message, and the DPF differential pressure message of the DPF model to the ECU, forming a closed loop and realizing the DPF regeneration function.

[0009] Preferably, the DOC model includes a DOC inlet temperature calculation module, a DOC outlet gas density calculation module, a DOC outlet temperature calculation module, and a DOC outlet air-fuel ratio calculation module;

[0010] The DOC inlet temperature calculation module obtains the DOC inlet temperature by looking up a table based on the engine speed and total fuel injection quantity provided by the engine model, or by looking up the turbine outlet temperature of the turbocharger model in the engine model.

[0011] The formula for calculating the DOC outlet gas density by the DOC outlet gas density calculation module is: DOC outlet gas density = DOC outlet pressure / [DOC outlet temperature * exhaust gas constant]. The DOC outlet pressure is calculated based on the DPF model, i.e., the DPF inlet pressure. The DOC outlet temperature is calculated by the DOC outlet temperature calculation module. The exhaust gas constant is obtained from the engine model.

[0012] The DOC outlet temperature calculation module calculates the DOC outlet temperature based on the energy conservation equation, i.e., the energy exchange in the DOC model = energy released by the combustion of the post-injection fuel - energy exchange of the exhaust gas flow rate in the DOC model - environmental heat loss in the DOC model. The DOC outlet temperature is then calculated as: DOC outlet temperature = energy exchange in the DOC model / specific heat capacity of the DOC model. The formula for calculating the energy released by the combustion of the post-injection fuel is:

[0013] Q post =m post (LHV)η con / 100

[0014] Among them, Q post The energy released by combustion of the fuel after injection, m post The fuel injection quantity is obtained from the engine model, LHV is the fuel calorific value, and η is the fuel injection quantity. con The hydrocarbon conversion efficiency is a function of the DOC inlet temperature.

[0015] The formula for calculating the energy exchange of exhaust gas flow in the DOC model is:

[0016] Q exh,DOC =(T out,DOC-T In,DOC *Exhaust gas flow rate* *Exhaust gas specific heat capacity at constant pressure*. The exhaust gas flow rate and exhaust gas specific heat capacity at constant pressure are obtained from the engine model. Q exh,DOC For the energy exchange of exhaust gas flow rate in the DOC model, T out,DOC T represents the DOC outlet temperature. In,DOC DOC inlet temperature;

[0017] The formula for calculating environmental heat loss in the DOC model is:

[0018] Q amb,DOC =(T out,DOC -T amb )-R th,DOC

[0019] Q amb,DOC This is the environmental heat loss in the DOC model, T amb It is the ambient temperature, obtained from the engine model, R th,DOC It is the DOC thermal resistance value, obtained from the DOC model;

[0020] The specific heat capacity of the DOC model = DOC internal specific heat capacity + DOC outlet gas density * DOC volume * exhaust gas constant volume specific heat capacity. The DOC internal specific heat capacity and DOC volume are obtained from the DOC model, and the exhaust gas constant volume specific heat capacity is obtained from the engine model.

[0021] The calculation formula for the DOC outlet air-fuel ratio calculation module is as follows:

[0022] λ out.DOC =m air / 14.6m fuel

[0023] Where, λ out.DOC The air-fuel ratio at DOC outlet.

[0024] m air =(m exh -m post ) / (1 / (14.6λ in.DOC )+1)

[0025] m fuel =m exh -m air

[0026] m exh λ is the exhaust gas flow rate. in.DOC For DOC inlet air-fuel ratio, m post The fuel injection amounts are all obtained from the engine model.

[0027] Preferably, the DPF model includes an air-fuel ratio calculation module, a soot calculation module, a DPF outlet temperature calculation module, and a DPF pressure calculation module;

[0028] The air-fuel ratio calculation module calculates the DPF outlet air-fuel ratio based on the DOC outlet air-fuel ratio using the forward Euler method.

[0029] The soot calculation module includes soot oxidation rate calculation and soot mass calculation. The soot oxidation rate is calculated based on the DPF outlet air-fuel ratio and DPF outlet temperature. The DPF outlet temperature is obtained by the DPF outlet temperature calculation module. The soot mass is calculated based on the soot oxidation rate and the initial soot mass. The initial soot mass is obtained from the engine model.

[0030] The DPF outlet temperature calculation module calculates the DPF outlet temperature based on the energy conservation equation, i.e., energy exchange in the DPF model = energy released by soot combustion - energy exchange of exhaust gas in the DPF model - environmental heat loss in the DPF model. The DPF outlet temperature is then calculated as: DPF outlet temperature = energy exchange in the DPF / specific heat capacity of the DPF model. The formula for calculating the energy released by soot combustion is:

[0031] Qr = RR th ΔH th m soot

[0032] Where Qr is the energy released by the combustion of soot, and RR th For the carbon soot oxidation rate, ΔH th Let m be the enthalpy of soot, and let m be a constant. soot For carbon soot quality;

[0033] The formula for calculating energy exchange of exhaust gas in the DPF model is:

[0034] Q exh,DPF =(T out,DPF -T In,DPF * Exhaust gas flow rate * Exhaust gas specific heat capacity at constant pressure, Q exh,DPF For the energy exchange of exhaust gas in the DPF model, T out,DPF T is the DPF outlet temperature. In,DPF The DPF inlet temperature, exhaust gas flow rate, and exhaust gas specific heat capacity at constant pressure were obtained from the engine model.

[0035] The formula for calculating ambient heat loss in the DPF model is:

[0036] Q amb,DPF =(T out,DPF -T amb )-R th,DPF

[0037] Q amb,DPF This refers to the environmental heat loss in the DPF model, T amb It is the ambient temperature, obtained from the engine model, Rth,DPF It is the DPF thermal resistance value, obtained from the DPF model;

[0038] The specific heat capacity of the DPF model = DPF internal specific heat capacity + DPF outlet gas density * DPF volume * exhaust gas constant volume specific heat capacity. The DPF internal specific heat capacity and DPF volume are obtained from the DPF model, the exhaust gas constant volume specific heat capacity is obtained from the engine model, and the DPF outlet gas density is calculated by the DPF pressure calculation module.

[0039] The DPF pressure calculation module calculates the DPF inlet pressure and DPF outlet gas density. DPF inlet pressure = DPF outlet pressure + DPF pressure drop. The DPF outlet pressure is obtained from a table based on the exhaust gas flow rate. The DPF pressure drop is obtained from a table based on the DPF inlet temperature, total flow rate, and S-carbon mass. The total flow rate is the sum of the post-injection fuel quantity and the exhaust gas flow rate. DPF outlet gas density = DPF outlet pressure / (DPF outlet temperature * exhaust gas constant). The exhaust gas constant is obtained from the engine model.

[0040] Preferably, the regeneration request includes a hard-wired regeneration request and a bus regeneration request. A hard-wired regeneration request refers to the ECU directly receiving the corresponding pin signal by simulating a switch signal through the HIL bench and requesting regeneration. A bus regeneration request is sent by simulating a message through the HIL bench, and the ECU requests regeneration by receiving the message signal.

[0041] Preferably, the regeneration test includes two types: normal regeneration and regeneration failure. Normal regeneration means that the entire regeneration process is successfully completed when the regeneration conditions are met. Regeneration failure includes failure when requesting regeneration and interruption during regeneration. Failure when requesting regeneration means that the conditions are not met when requesting regeneration, so regeneration cannot be entered. Interruption during regeneration means that the conditions are not met when regeneration is in progress, so regeneration will be terminated, resulting in regeneration failure.

[0042] A regeneration test method for the DPF regeneration function test system includes the following steps:

[0043] A) Begin;

[0044] B) Power on and start the engine;

[0045] C) Run;

[0046] D) Check if the necessary conditions for regeneration are met. If all conditions are met, proceed to step F); otherwise, proceed to step E.

[0047] E) Check for unmet conditions, adjust the operating conditions to meet the conditions, and proceed to step C).

[0048] F) Check if the initial regeneration conditions are met. If they are met, proceed to the next step; otherwise, proceed to step E).

[0049] G) Check if the regeneration status is satisfied. If satisfied, proceed to the next step; otherwise, proceed to step E).

[0050] H) Issue a regeneration request;

[0051] I) Trigger a parking regeneration request, check the necessary conditions for regeneration, if none are met, proceed to the next step; otherwise, proceed to step E).

[0052] J) Press the parking regeneration switch; regeneration is in progress.

[0053] K) Regeneration complete;

[0054] L) End.

[0055] Preferably, in step J), if regeneration is interrupted, resulting in regeneration failure, then the cause of the regeneration failure is analyzed.

[0056] Preferably, in step D), the necessary conditions for regeneration include start conditions, vehicle conditions, and environmental conditions. The start conditions include water temperature greater than the temperature limit, carbon load less than the limit, and regeneration request status as Inactive. The vehicle conditions include engine in running state, vehicle speed less than the limit, gear in neutral, clutch released, handbrake engaged, and foot brake released. The environmental conditions include water temperature within the limit range, fuel temperature within the limit range, DOC inlet temperature within the limit range, turbine inlet temperature within the limit range, engine not in torque-limited state, DPF inlet temperature less than the limit, and regeneration prohibited from starting.

[0057] Preferably, in step F), the initial regeneration conditions include regeneration scheduling conditions and carbon loading conditions. The regeneration scheduling conditions are met by setting a specific calibration value to 1 or simulating a DPF regeneration failure. The carbon loading condition is determined by the ECU estimating the current carbon loading based on the DPF differential pressure signal sent by the DPF model, and then comparing it with the limit for triggering regeneration. The DPF differential pressure signal is adjusted on a test bench to ensure that the carbon loading estimated by the ECU based on the differential pressure meets the conditions.

[0058] Preferably, in step E), when adjusting the operating conditions, all necessary conditions for regeneration are met, and the initial conditions and regeneration status are reconfirmed. If they are met, the parking regeneration switch is pressed directly; if they are not met, a re-check is required.

[0059] Compared with the prior art, the present invention has the following advantages:

[0060] 1. Compared with the currently widely used real vehicle testing and engine bench testing, the present invention has higher economic efficiency. The present invention establishes a testing system based on hardware-in-the-loop testing technology, which can be adaptively adjusted for different models of engine ECUs and has universality. That is, one testing system can test different models of engine ECUs, eliminating the purchase cost of test vehicles and engines in real vehicle testing or engine bench testing, and improving the economic efficiency of testing.

[0061] 2. Compared with the currently widely used real vehicle testing and engine bench testing, this invention has higher environmental protection and efficiency. The test system is based on hardware-in-the-loop testing technology, which eliminates the need for real engines and vehicles, reducing emissions. Testers can simulate different working conditions through the test system, which is easy to operate and improves efficiency.

[0062] 3. It avoids the need to wait for the working conditions to be met before testing in real vehicle testing. By simulating the working conditions through this system, the time can be shortened and the efficiency improved.

[0063] 4. It avoids increased fuel consumption during real-vehicle testing, saving costs;

[0064] 5. It avoids the increased emissions from real-vehicle testing, thus preventing environmental pollution;

[0065] 6. It can achieve automated testing, the regeneration judgment conditions are easy to adjust, and the testing efficiency is high. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the DPF regeneration function testing system of the present invention;

[0067] Figure 2 for Figure 1 A schematic diagram illustrating the principle of the DOC model;

[0068] Figure 3 for Figure 1 A schematic diagram of the DPF model principle in the document;

[0069] Figure 4 This is a flowchart of the regeneration test of the DPF regeneration function test system of the present invention. Detailed Implementation

[0070] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0073] Example 1

[0074] like Figure 1 As shown, a DPF regeneration function test system includes an engine hardware-in-the-loop test system, comprising a vehicle model and an engine model, and further including a DOC model connected in series with the engine model and a DPF model connected in series with the DOC model. By collecting the post-injection fuel quantity, the system simulates and sends the DOC inlet temperature message, the DOC outlet temperature message, the DPF outlet temperature message, and the DPF differential pressure message of the DPF model to the ECU, forming a closed loop to realize the DPF regeneration function.

[0075] During testing in this embodiment, if Figure 4 As shown, it includes the following steps:

[0076] A) Begin;

[0077] B) Power on and start the engine;

[0078] C) Run;

[0079] D) Check if the necessary conditions for regeneration are met. If all conditions are met, proceed to step F); otherwise, proceed to step E.

[0080] E) Check for unmet conditions, adjust the operating conditions to meet the conditions, and proceed to step C).

[0081] F) Check if the initial regeneration conditions are met. If they are met, proceed to the next step; otherwise, proceed to step E).

[0082] G) Check if the regeneration status is satisfied. If satisfied, proceed to the next step; otherwise, proceed to step E).

[0083] H) Issue a regeneration request;

[0084] I) Trigger a parking regeneration request, check the necessary conditions for regeneration, if none are met, proceed to the next step; otherwise, proceed to step E).

[0085] J) Press the parking regeneration switch; regeneration is in progress.

[0086] K) Regeneration complete;

[0087] L) End.

[0088] Example 2

[0089] like Figure 1 As shown, a DPF regeneration function test system includes an engine hardware-in-the-loop test system, comprising a vehicle model and an engine model, and further including a DOC model connected in series with the engine model and a DPF model connected in series with the DOC model. By collecting the post-injection fuel quantity, the system simulates and sends the DOC inlet temperature message, the DOC outlet temperature message, the DPF outlet temperature message, and the DPF differential pressure message of the DPF model to the ECU, forming a closed loop to realize the DPF regeneration function.

[0090] Among them, such as Figure 2 As shown, the DOC model includes a DOC inlet temperature calculation module, a DOC outlet gas density calculation module, a DOC outlet temperature calculation module, and a DOC outlet air-fuel ratio calculation module;

[0091] The DOC inlet temperature calculation module obtains the DOC inlet temperature by looking up a table based on the engine speed and total fuel injection quantity provided by the engine model, or by looking up the turbine outlet temperature of the turbocharger model in the engine model.

[0092] The formula for calculating the DOC outlet gas density by the DOC outlet gas density calculation module is: DOC outlet gas density = DOC outlet pressure / [DOC outlet temperature * exhaust gas constant]. The DOC outlet pressure is calculated based on the DPF model, i.e., the DPF inlet pressure. The DOC outlet temperature is calculated by the DOC outlet temperature calculation module. The exhaust gas constant is obtained from the engine model.

[0093] The DOC outlet temperature calculation module calculates the DOC outlet temperature based on the energy conservation equation, i.e., the energy exchange in the DOC model = energy released by the combustion of the post-injection fuel - energy exchange of the exhaust gas flow rate in the DOC model - environmental heat loss in the DOC model. The DOC outlet temperature is then calculated as: DOC outlet temperature = energy exchange in the DOC model / specific heat capacity of the DOC model. The formula for calculating the energy released by the combustion of the post-injection fuel is:

[0094] Q post =m post (LHV)η con / 100

[0095] Among them, Q post The energy released by combustion of the fuel after injection, m post The fuel injection quantity is obtained from the engine model, LHV is the fuel calorific value, and η is the fuel injection quantity. con The hydrocarbon conversion efficiency is a function of the DOC inlet temperature.

[0096] The formula for calculating the energy exchange of exhaust gas flow in the DOC model is:

[0097] Q exh,DOC =(T out,DOC -T In,DOC *Exhaust gas flow rate* *Exhaust gas specific heat capacity at constant pressure*. The exhaust gas flow rate and exhaust gas specific heat capacity at constant pressure are obtained from the engine model. Q exh,DOC For the energy exchange of exhaust gas flow rate in the DOC model, T out,DOC T represents the DOC outlet temperature. In,DOC DOC inlet temperature;

[0098] The formula for calculating environmental heat loss in the DOC model is:

[0099] Q amb,DOC =(T out,DOC -T amb )-R th,DOC

[0100] Q amb,DOC This is the environmental heat loss in the DOC model, T amb It is the ambient temperature, obtained from the engine model, R th,DOC It is the DOC thermal resistance value, obtained from the DOC model;

[0101] The specific heat capacity of the DOC model = DOC internal specific heat capacity + DOC outlet gas density * DOC volume * exhaust gas constant volume specific heat capacity. The DOC internal specific heat capacity and DOC volume are obtained from the DOC model, and the exhaust gas constant volume specific heat capacity is obtained from the engine model.

[0102] The calculation formula for the DOC outlet air-fuel ratio calculation module is as follows:

[0103] λ out.DOC =m air / 14.6m fuel

[0104] Where, λ out.DOC The air-fuel ratio at DOC outlet.

[0105] m air =(m exh -m post ) / (1 / (14.6λ in.DOC )+1)

[0106] m fuel =m exh -m air

[0107] m exh λ is the exhaust gas flow rate. in.DOC For DOC inlet air-fuel ratio, m post The fuel injection amounts are all obtained from the engine model;

[0108] like Figure 3 As shown, the DPF model includes an air-fuel ratio calculation module, a soot calculation module, a DPF outlet temperature calculation module, and a DPF pressure calculation module;

[0109] The air-fuel ratio calculation module calculates the DPF outlet air-fuel ratio based on the DOC outlet air-fuel ratio using the forward Euler method.

[0110] The soot calculation module includes soot oxidation rate calculation and soot mass calculation. The soot oxidation rate is calculated based on the DPF outlet air-fuel ratio and DPF outlet temperature. The DPF outlet temperature is obtained by the DPF outlet temperature calculation module. The soot mass is calculated based on the soot oxidation rate and the initial soot mass. The initial soot mass is obtained from the engine model.

[0111] The DPF outlet temperature calculation module calculates the DPF outlet temperature based on the energy conservation equation, i.e., energy exchange in the DPF model = energy released by soot combustion - energy exchange of exhaust gas in the DPF model - environmental heat loss in the DPF model. The DPF outlet temperature is then calculated as: DPF outlet temperature = energy exchange in the DPF / specific heat capacity of the DPF model. The formula for calculating the energy released by soot combustion is:

[0112] Qr = RR th ΔH th m soot

[0113] Where Qr is the energy released by the combustion of soot, and RR th For the carbon soot oxidation rate, ΔH th Let m be the enthalpy of soot, and let m be a constant. sootFor carbon soot quality;

[0114] The formula for calculating energy exchange of exhaust gas in the DPF model is:

[0115] Q exh,DPF =(T out,DPF -T In,DPF * Exhaust gas flow rate * Exhaust gas specific heat capacity at constant pressure, Q exh,DPF For the energy exchange of exhaust gas in the DPF model, T out,DPF T is the DPF outlet temperature. In,DPF The DPF inlet temperature, exhaust gas flow rate, and exhaust gas specific heat capacity at constant pressure were obtained from the engine model.

[0116] The formula for calculating ambient heat loss in the DPF model is:

[0117] Q amb,DPF =(T out,DPF -T amb )-R th,DPF

[0118] Q amb,DPF This refers to the environmental heat loss in the DPF model, T amb It is the ambient temperature, obtained from the engine model, R th,DPF It is the DPF thermal resistance value, obtained from the DPF model;

[0119] The specific heat capacity of the DPF model = DPF internal specific heat capacity + DPF outlet gas density * DPF volume * exhaust gas constant volume specific heat capacity. The DPF internal specific heat capacity and DPF volume are obtained from the DPF model, the exhaust gas constant volume specific heat capacity is obtained from the engine model, and the DPF outlet gas density is calculated by the DPF pressure calculation module.

[0120] The DPF pressure calculation module calculates the DPF inlet pressure and DPF outlet gas density. DPF inlet pressure = DPF outlet pressure + DPF pressure drop. The DPF outlet pressure is obtained from a table based on the exhaust gas flow rate. The DPF pressure drop is obtained from a table based on the DPF inlet temperature, total flow rate, and S-carbon mass. The total flow rate is the sum of the post-injection fuel quantity and the exhaust gas flow rate. DPF outlet gas density = DPF outlet pressure / (DPF outlet temperature * exhaust gas constant). The exhaust gas constant is obtained from the engine model.

[0121] When using this embodiment, as follows: Figure 4 As shown, it includes the following steps:

[0122] A) Begin;

[0123] B) Power on and start the engine;

[0124] C) Run;

[0125] D) Check if the necessary conditions for regeneration are met. If all conditions are met, proceed to step F); otherwise, proceed to step E.

[0126] E) Check for unmet conditions, adjust the operating conditions to meet the conditions, and proceed to step C).

[0127] F) Check if the initial regeneration conditions are met. If they are met, proceed to the next step; otherwise, proceed to step E).

[0128] G) Check if the regeneration status is satisfied. If satisfied, proceed to the next step; otherwise, proceed to step E).

[0129] H) Issue a regeneration request;

[0130] I) Trigger a parking regeneration request, check the necessary conditions for regeneration, if none are met, proceed to the next step; otherwise, proceed to step E).

[0131] J) Press the parking regeneration switch; regeneration is in progress.

[0132] K) Regeneration complete;

[0133] L) End.

[0134] In addition, if regeneration is interrupted in step J), resulting in regeneration failure, the cause of the regeneration failure will be analyzed.

[0135] Example 3

[0136] like Figure 1 As shown, a DPF regeneration function test system includes an engine hardware-in-the-loop test system, comprising a vehicle model and an engine model, as well as a DOC model connected in series with the engine model and a DPF model connected in series with the DOC model. By collecting the post-injection fuel quantity, the system simulates and sends the DOC inlet temperature message, DOC outlet temperature message, DPF outlet temperature message, and DPF differential pressure message of the DPF model to the ECU, forming a closed loop to realize the DPF regeneration function.

[0137] Among them, such as Figure 2 As shown, the DOC model includes a DOC inlet temperature calculation module, a DOC outlet gas density calculation module, a DOC outlet temperature calculation module, and a DOC outlet air-fuel ratio calculation module;

[0138] The DOC inlet temperature calculation module obtains the DOC inlet temperature by looking up a table based on the engine speed and total fuel injection quantity provided by the engine model, or by looking up the turbine outlet temperature of the turbocharger model in the engine model.

[0139] The formula for calculating the DOC outlet gas density by the DOC outlet gas density calculation module is: DOC outlet gas density = DOC outlet pressure / [DOC outlet temperature * exhaust gas constant]. The DOC outlet pressure is calculated based on the DPF model, i.e., the DPF inlet pressure. The DOC outlet temperature is calculated by the DOC outlet temperature calculation module. The exhaust gas constant is obtained from the engine model.

[0140] The DOC outlet temperature calculation module calculates the DOC outlet temperature based on the energy conservation equation, i.e., the energy exchange in the DOC model = energy released by the combustion of the post-injection fuel - energy exchange of the exhaust gas flow rate in the DOC model - environmental heat loss in the DOC model. The DOC outlet temperature is then calculated as: DOC outlet temperature = energy exchange in the DOC model / specific heat capacity of the DOC model. The formula for calculating the energy released by the combustion of the post-injection fuel is:

[0141] Q post =m post (LHV)η con / 100

[0142] Among them, Q post The energy released by combustion of the fuel after injection, m post The fuel injection quantity is obtained from the engine model, LHV is the fuel calorific value, and η is the fuel injection quantity. con The hydrocarbon conversion efficiency is a function of the DOC inlet temperature.

[0143] The formula for calculating the energy exchange of exhaust gas flow in the DOC model is:

[0144] Q exh,DOC =(T out,DOC -T In,DOC *Exhaust gas flow rate* *Exhaust gas specific heat capacity at constant pressure*. The exhaust gas flow rate and exhaust gas specific heat capacity at constant pressure are obtained from the engine model. Q exh,DOC For the energy exchange of exhaust gas flow rate in the DOC model, T out,DOC T represents the DOC outlet temperature. In,DOC DOC inlet temperature;

[0145] The formula for calculating environmental heat loss in the DOC model is:

[0146] Q amb,DOC =(T out,DOC -T amb )-R th,DOC

[0147] Q amb,DOC This is the environmental heat loss in the DOC model, T amb It is the ambient temperature, obtained from the engine model, R th,DOC It is the DOC thermal resistance value, obtained from the DOC model;

[0148] The specific heat capacity of the DOC model = DOC internal specific heat capacity + DOC outlet gas density * DOC volume * exhaust gas constant volume specific heat capacity. The DOC internal specific heat capacity and DOC volume are obtained from the DOC model, and the exhaust gas constant volume specific heat capacity is obtained from the engine model.

[0149] The calculation formula for the DOC outlet air-fuel ratio calculation module is as follows:

[0150] λ out.DOC =m air / 14.6m fuel

[0151] Where, λ out.DOC The air-fuel ratio at DOC outlet.

[0152] m air =(m exh -m post ) / (1 / (14.6λ in.DOC )+1)

[0153] m fuel =m exh -m air

[0154] m exh λ is the exhaust gas flow rate. in.DOC For DOC inlet air-fuel ratio, m post The fuel injection amounts are all obtained from the engine model;

[0155] like Figure 3 As shown, the DPF model includes an air-fuel ratio calculation module, a soot calculation module, a DPF outlet temperature calculation module, and a DPF pressure calculation module;

[0156] The air-fuel ratio calculation module calculates the DPF outlet air-fuel ratio based on the DOC outlet air-fuel ratio using the forward Euler method.

[0157] The soot calculation module includes soot oxidation rate calculation and soot mass calculation. The soot oxidation rate is calculated based on the DPF outlet air-fuel ratio and DPF outlet temperature. The DPF outlet temperature is obtained by the DPF outlet temperature calculation module. The soot mass is calculated based on the soot oxidation rate and the initial soot mass. The initial soot mass is obtained from the engine model.

[0158] The DPF outlet temperature calculation module calculates the DPF outlet temperature based on the energy conservation equation, i.e., energy exchange in the DPF model = energy released by soot combustion - energy exchange of exhaust gas in the DPF model - environmental heat loss in the DPF model. The DPF outlet temperature is then calculated as: DPF outlet temperature = energy exchange in the DPF / specific heat capacity of the DPF model. The formula for calculating the energy released by soot combustion is:

[0159] Qr = RR th ΔH th m soot

[0160] Where Qr is the energy released by the combustion of soot, and RR th For the carbon soot oxidation rate, ΔH th Let m be the enthalpy of soot, and let m be a constant. soot For carbon soot quality;

[0161] The formula for calculating energy exchange of exhaust gas in the DPF model is:

[0162] Q exh,DPF =(T out,DPF -T In,DPF * Exhaust gas flow rate * Exhaust gas specific heat capacity at constant pressure, Q exh,DPF For the energy exchange of exhaust gas in the DPF model, T out,DPF T is the DPF outlet temperature. In,DPF The DPF inlet temperature, exhaust gas flow rate, and exhaust gas specific heat capacity at constant pressure were obtained from the engine model.

[0163] The formula for calculating ambient heat loss in the DPF model is:

[0164] Q amb,DPF =(T out,DPF -T amb )-R th,DPF

[0165] Q amb,DPF This refers to the environmental heat loss in the DPF model, T amb It is the ambient temperature, obtained from the engine model, R th,DPF It is the DPF thermal resistance value, obtained from the DPF model;

[0166] The specific heat capacity of the DPF model = DPF internal specific heat capacity + DPF outlet gas density * DPF volume * exhaust gas constant volume specific heat capacity. The DPF internal specific heat capacity and DPF volume are obtained from the DPF model, the exhaust gas constant volume specific heat capacity is obtained from the engine model, and the DPF outlet gas density is calculated by the DPF pressure calculation module.

[0167] The DPF pressure calculation module calculates the DPF inlet pressure and DPF outlet gas density. DPF inlet pressure = DPF outlet pressure + DPF pressure drop. The DPF outlet pressure is obtained from a table based on the exhaust gas flow rate. The DPF pressure drop is obtained from a table based on the DPF inlet temperature, total flow rate, and S-carbon mass. The total flow rate is the sum of the post-injection fuel quantity and the exhaust gas flow rate. DPF outlet gas density = DPF outlet pressure / (DPF outlet temperature * exhaust gas constant). The exhaust gas constant is obtained from the engine model.

[0168] When using this embodiment, as follows: Figure 4As shown, it includes the following steps:

[0169] A) Begin;

[0170] B) Power on and start the engine;

[0171] C) Run;

[0172] D) Check if the necessary conditions for regeneration are met. If all conditions are met, proceed to step F); otherwise, proceed to step E.

[0173] E) Check for unmet conditions, adjust the operating conditions to meet the conditions, and proceed to step C).

[0174] F) Check if the initial regeneration conditions are met. If they are met, proceed to the next step; otherwise, proceed to step E).

[0175] G) Check if the regeneration status is satisfied. If satisfied, proceed to the next step; otherwise, proceed to step E).

[0176] H) Issue a regeneration request;

[0177] I) Trigger a parking regeneration request, check the necessary conditions for regeneration, if none are met, proceed to the next step; otherwise, proceed to step E).

[0178] J) Press the parking regeneration switch; regeneration is in progress.

[0179] K) Regeneration complete;

[0180] L) End.

[0181] In addition, if regeneration is interrupted in step J), resulting in regeneration failure, the cause of the regeneration failure will be analyzed.

[0182] In this embodiment, the regeneration request includes a hard-wired regeneration request and a bus regeneration request. The hard-wired regeneration request refers to the ECU directly receiving the corresponding pin signal through the HIL bench to request regeneration. The bus regeneration request is sent through the HIL bench to simulate a message, and the ECU requests regeneration by receiving the message signal.

[0183] Regeneration testing includes two types: normal regeneration and regeneration failure. Normal regeneration means that the entire regeneration process is successfully completed when the regeneration conditions are met. Regeneration failure includes failure when requesting regeneration and interruption during regeneration. Failure when requesting regeneration means that the conditions are not met when requesting regeneration, so regeneration cannot be started. Interruption during regeneration means that the conditions are not met during regeneration, so regeneration will be terminated, resulting in regeneration failure.

[0184] When using this embodiment, the following steps are included:

[0185] A) Begin;

[0186] B) Power on and start the engine;

[0187] C) Run;

[0188] D) Check if the necessary conditions for regeneration are met. If all conditions are met, proceed to step F); otherwise, proceed to step E.

[0189] E) Check for unmet conditions, adjust the operating conditions to meet the conditions, and proceed to step C).

[0190] F) Check if the initial regeneration conditions are met. If they are met, proceed to the next step; otherwise, proceed to step E).

[0191] G) Check if the regeneration status is satisfied. If satisfied, proceed to the next step; otherwise, proceed to step E).

[0192] H) Issue a regeneration request;

[0193] I) Trigger a parking regeneration request, check the necessary conditions for regeneration, if none are met, proceed to the next step; otherwise, proceed to step E).

[0194] J) Press the parking regeneration switch; regeneration is in progress.

[0195] K) Regeneration complete;

[0196] L) End.

[0197] In addition, if regeneration is interrupted in step J), resulting in regeneration failure, the cause of the regeneration failure will be analyzed.

[0198] In step D), the necessary conditions for regeneration include start conditions, vehicle conditions, and environmental conditions. Start conditions include coolant temperature greater than the temperature limit, carbon load less than the limit, and regeneration request status as Inactive. Vehicle conditions include engine in running state, vehicle speed less than the limit, gear in neutral, clutch released, handbrake engaged, and foot brake released. Environmental conditions include coolant temperature within the limit range, fuel temperature within the limit range, DOC inlet temperature within the limit range, turbine inlet temperature within the limit range, engine not in torque-limited state, DPF inlet temperature less than the limit, and regeneration prohibited from starting.

[0199] In step F), the initial regeneration conditions include regeneration scheduling conditions and carbon load conditions. The regeneration scheduling conditions are met by setting a specific calibrated value to 1 or simulating a DPF regeneration failure. The carbon load condition is determined by the ECU estimating the current carbon load based on the DPF differential pressure signal sent by the DPF model, and then comparing it with the limit for triggering regeneration. The DPF differential pressure signal is adjusted on the test bench to ensure that the carbon load estimated by the ECU based on the differential pressure meets the conditions.

[0200] In step E), when adjusting the operating conditions, ensure that all necessary conditions for regeneration are met, and reconfirm whether the initial conditions and regeneration status are met. If they are met, press the parking regeneration switch directly; otherwise, recheck.

[0201] After regeneration begins, a waiting period is required, typically half an hour. To shorten the testing time, the regeneration time can be reduced by adjusting the DPF inlet temperature or carbon load. Once regeneration is complete, the ECU will indicate that regeneration is complete and regeneration is OK.

[0202] Additionally, in step J), pressing the DPF regeneration disable switch interrupts regeneration, and a regeneration failure message can be seen through the ECU monitoring. This regeneration failure test uses the regeneration disable switch being on as an example. If other conditions need to be tested, such as pressing the clutch or accelerator, regeneration needs to be restarted, and then the regeneration interruption condition needs to be triggered.

[0203] This invention, a DPF regeneration function testing system and its regeneration testing method, offers greater economic advantages compared to currently widely used real-vehicle testing and engine bench testing. Based on hardware-in-the-loop (HIL) testing technology, the system can be adapted to different engine ECU models, possessing versatility. This means a single testing system can test various engine ECU models, eliminating the need for test vehicles and engine purchases required for real-vehicle or engine bench testing, thus improving testing efficiency. Furthermore, this invention offers greater environmental friendliness and efficiency compared to current real-vehicle and engine bench testing methods. The hardware-in-the-loop testing system eliminates the need for actual engines and vehicles, reducing emissions. Testing personnel can simulate different operating conditions through the system, facilitating operation and improving efficiency. It avoids the need to wait for conditions to be met during real-vehicle testing, shortening testing time and increasing efficiency. It also avoids increased fuel consumption and costs associated with real-vehicle testing, and prevents increased emissions and environmental pollution. Finally, it enables automated testing, with easily adjustable regeneration judgment conditions and high testing efficiency.

[0204] It should be noted that the above description of the technical solutions is exemplary, and this specification may be embodied in different forms and should not be construed as limiting it to the technical solutions set forth herein. Rather, providing these descriptions will ensure that the disclosure of this invention is thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Furthermore, the technical solutions of this invention are defined only by the scope of the claims.

[0205] The aspects disclosed in this specification and claims are merely examples, and therefore, this specification and claims are not limited to the details shown. In the foregoing description, detailed descriptions of relevant known functions or configurations have been omitted where it would unnecessarily obscure the focus of this specification and claims.

[0206] When using the terms “comprising,” “having,” and “including” as described in this specification, there may be another part or other part unless used, and the terms used are generally singular but may also be plural.

[0207] Finally, it should be noted that the above description is a further detailed explanation of the invention in conjunction with specific embodiments. It should not be considered that the specific implementation of the invention is limited to these descriptions. For those skilled in the art, any simple substitutions made without departing from the concept of the invention should be considered within the scope of protection of this invention. The above embodiments are merely representative examples of the invention. Obviously, the invention is not limited to the above embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the invention should be considered within the scope of protection of this invention.

[0208] It should be noted that the above description of the technical solutions is exemplary, and this specification may be embodied in different forms and should not be construed as limiting it to the technical solutions set forth herein. Rather, providing these descriptions will ensure that the disclosure of this invention is thorough and complete, and will fully convey the scope of this specification to those skilled in the art. Furthermore, the technical solutions of this invention are defined only by the scope of the claims. Features of various embodiments of this invention may be combined or spliced ​​together in part or in whole, and may be implemented in various different configurations as will be fully understood by those skilled in the art. Embodiments of this invention may be implemented independently of each other or may be implemented together in an interdependent relationship.

[0209] For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and the above structures should all be considered to fall within the protection scope of the present invention.

Claims

1. A DPF regeneration function testing system, comprising an engine hardware-in-the-loop testing system, including a vehicle model and an engine model, characterized in that: It also includes a DOC model connected in series with the engine model and a DPF model connected in series with the DOC model. By collecting the post-injection fuel quantity, it simulates and sends the DOC inlet temperature message, the DOC outlet temperature message, the DPF outlet temperature message, and the DPF differential pressure message of the DPF model to the ECU to form a closed loop and realize the DPF regeneration function. The DOC model includes a DOC inlet temperature calculation module, a DOC outlet gas density calculation module, a DOC outlet temperature calculation module, and a DOC outlet air-fuel ratio calculation module. The DOC inlet temperature calculation module obtains the DOC inlet temperature by looking up a table based on the engine speed and total fuel injection quantity provided by the engine model, or by looking up the turbine outlet temperature of the turbocharger model in the engine model. The formula for calculating the DOC outlet gas density by the DOC outlet gas density calculation module is: DOC outlet gas density = DOC outlet pressure / [DOC outlet temperature * exhaust gas constant]. The DOC outlet pressure is calculated based on the DPF model, i.e., the DPF inlet pressure. The DOC outlet temperature is calculated by the DOC outlet temperature calculation module. The exhaust gas constant is obtained from the engine model. The DOC outlet temperature calculation module calculates the DOC outlet temperature based on the energy conservation equation, i.e., the energy exchange in the DOC model = energy released by the combustion of the post-injection fuel - energy exchange of the exhaust gas flow rate in the DOC model - environmental heat loss in the DOC model. The DOC outlet temperature is then calculated as: DOC outlet temperature = energy exchange in the DOC model / specific heat capacity of the DOC model. The formula for calculating the energy released by the combustion of the post-injection fuel is: Q post =m post (LHV)η con / 100 Among them, Q post The energy released by combustion of the fuel after injection, m post The fuel injection quantity is obtained from the engine model, LHV is the fuel calorific value, and η is the fuel injection quantity. con The hydrocarbon conversion efficiency is a function of the DOC inlet temperature. The formula for calculating the energy exchange of exhaust gas flow in the DOC model is: Q exh,DOC =(T out,DOC -T In,DOC *Exhaust gas flow rate* *Exhaust gas specific heat capacity at constant pressure*. The exhaust gas flow rate and exhaust gas specific heat capacity at constant pressure are obtained from the engine model. Q exh,DOC For the energy exchange of exhaust gas flow rate in the DOC model, T out,DOC T represents the DOC outlet temperature. In,DOC DOC inlet temperature; The formula for calculating environmental heat loss in the DOC model is: Q amb,DOC =(T out,DOC -T amb )-R th,DOC Q amb,DOC This is the environmental heat loss in the DOC model, T amb It is the ambient temperature, obtained from the engine model, R th,DOC It is the DOC thermal resistance value, obtained from the DOC model; The specific heat capacity of the DOC model = DOC internal specific heat capacity + DOC outlet gas density * DOC volume * exhaust gas constant volume specific heat capacity. The DOC internal specific heat capacity and DOC volume are obtained from the DOC model, and the exhaust gas constant volume specific heat capacity is obtained from the engine model. The calculation formula for the DOC outlet air-fuel ratio calculation module is as follows: l out.DOC =m air / 14.6m fuel Where, λ out.DOC The air-fuel ratio at DOC outlet. m air =(m exh -m post ) / (1 / (14.6λ in.DOC )+1) m fuel =m exh -m air m exh λ is the exhaust gas flow rate. in.DOC For DOC inlet air-fuel ratio, m post The fuel injection amounts are all obtained from the engine model.

2. The DPF regeneration function testing system according to claim 1, characterized in that: The DPF model includes an air-fuel ratio calculation module, a soot calculation module, a DPF outlet temperature calculation module, and a DPF pressure calculation module. The air-fuel ratio calculation module calculates the DPF outlet air-fuel ratio based on the DOC outlet air-fuel ratio using the forward Euler method. The soot calculation module includes soot oxidation rate calculation and soot mass calculation. The soot oxidation rate is calculated based on the DPF outlet air-fuel ratio and DPF outlet temperature. The DPF outlet temperature is obtained by the DPF outlet temperature calculation module. The soot mass is calculated based on the soot oxidation rate and the initial soot mass. The initial soot mass is obtained from the engine model. The DPF outlet temperature calculation module calculates the DPF outlet temperature based on the energy conservation equation, i.e., energy exchange in the DPF model = energy released by soot combustion - energy exchange of exhaust gas in the DPF model - environmental heat loss in the DPF model. The DPF outlet temperature is then calculated as: DPF outlet temperature = energy exchange in the DPF / specific heat capacity of the DPF model. The formula for calculating the energy released by soot combustion is: Qr=RR th ΔH th m soot Where Qr is the energy released by the combustion of soot, and RR th For the carbon soot oxidation rate, ΔH th Let m be the enthalpy of soot, and let m be a constant. soot For carbon soot quality; The formula for calculating energy exchange of exhaust gas in the DPF model is: Q exh,DPF =(T out,DPF -T In,DPF * Exhaust gas flow rate * Exhaust gas specific heat capacity at constant pressure, Q exh,DPF For the energy exchange of exhaust gas in the DPF model, T out,DPF T is the DPF outlet temperature. In,DPF The DPF inlet temperature, exhaust gas flow rate, and exhaust gas specific heat capacity at constant pressure were obtained from the engine model. The formula for calculating ambient heat loss in the DPF model is: Q amb,DPF =(T out,DPF -T amb )-R th,DPF Q amb,DPF This refers to the environmental heat loss in the DPF model, T amb It is the ambient temperature, obtained from the engine model, R th,DPF It is the DPF thermal resistance value, obtained from the DPF model; The specific heat capacity of the DPF model = DPF internal specific heat capacity + DPF outlet gas density * DPF volume * exhaust gas constant volume specific heat capacity. The DPF internal specific heat capacity and DPF volume are obtained from the DPF model, the exhaust gas constant volume specific heat capacity is obtained from the engine model, and the DPF outlet gas density is calculated by the DPF pressure calculation module. The DPF pressure calculation module calculates the DPF inlet pressure and DPF outlet gas density. DPF inlet pressure = DPF outlet pressure + DPF pressure drop. The DPF outlet pressure is obtained from a table based on the exhaust gas flow rate. The DPF pressure drop is obtained from a table based on the DPF inlet temperature, total flow rate, and S-carbon mass. The total flow rate is the sum of the post-injection fuel quantity and the exhaust gas flow rate. DPF outlet gas density = DPF outlet pressure / (DPF outlet temperature * exhaust gas constant). The exhaust gas constant is obtained from the engine model.

3. The DPF regeneration function testing system according to claim 1, characterized in that: Regeneration requests include hard-wired regeneration requests and bus regeneration requests. Hard-wired regeneration requests refer to the ECU directly receiving the corresponding pin signal by simulating a switch signal via the HIL bench and requesting regeneration. Bus regeneration requests are sent by simulating a message via the HIL bench, and the ECU requests regeneration by receiving the message signal.

4. The DPF regeneration function testing system according to claim 1, characterized in that: Regeneration testing includes two types: normal regeneration and regeneration failure. Normal regeneration means that the entire regeneration process is successfully completed when the regeneration conditions are met. Regeneration failure includes failure when requesting regeneration and interruption during regeneration. Failure when requesting regeneration means that the conditions are not met when requesting regeneration, so regeneration cannot be started. Interruption during regeneration means that the conditions are not met during regeneration, so regeneration will be terminated, resulting in regeneration failure.

5. A regeneration test method for the DPF regeneration function test system as described in claim 1, characterized in that: Includes the following steps: A) Begin; B) Power on and start the engine; C) Run; D) Check if the necessary conditions for regeneration are met. If all conditions are met, proceed to step F); otherwise, proceed to step E. E) Check for unmet conditions, adjust the operating conditions to meet the conditions, and proceed to step C). F) Check if the initial regeneration conditions are met. If they are met, proceed to the next step; otherwise, proceed to step E). G) Check if the regeneration status is satisfied. If satisfied, proceed to the next step; otherwise, proceed to step E). H) Issue a regeneration request; I) Trigger a parking regeneration request, check the necessary conditions for regeneration, if none are met, proceed to the next step; otherwise, proceed to step E). J) Press the parking regeneration switch; regeneration is in progress. K) Regeneration complete; L) End.

6. The regeneration test method of the DPF regeneration function test system according to claim 5, characterized in that: In step J), if regeneration is interrupted, resulting in regeneration failure, then the cause of the regeneration failure will be analyzed.

7. The regeneration test method of the DPF regeneration function test system according to claim 5, characterized in that: In step D), the necessary conditions for regeneration include start conditions, vehicle conditions, and environmental conditions. Start conditions include water temperature greater than the temperature limit, carbon load less than the limit, and regeneration request status as Inactive. Vehicle conditions include engine in running state, vehicle speed less than the limit, gear in neutral, clutch released, handbrake engaged, and foot brake released. Environmental conditions include water temperature within the limit range, fuel temperature within the limit range, DOC inlet temperature within the limit range, turbine inlet temperature within the limit range, engine not in torque-limited state, DPF inlet temperature less than the limit, and regeneration prohibited from starting.

8. The regeneration test method of the DPF regeneration function test system according to claim 5, characterized in that: In step F), the initial regeneration conditions include regeneration scheduling conditions and carbon load conditions. The regeneration scheduling conditions are met by setting a specific calibrator to 1 or simulating a DPF regeneration failure. The carbon load conditions are met by the ECU estimating the current carbon load based on the DPF differential pressure signal sent by the DPF model, and then comparing it with the limit for triggering regeneration. The DPF differential pressure signal is adjusted on the bench to make the carbon load estimated by the ECU based on the differential pressure meet the conditions.

9. The regeneration test method of the DPF regeneration function test system according to claim 5, characterized in that: In step E), when adjusting the operating conditions, ensure that all necessary conditions for regeneration are met, and reconfirm whether the initial conditions and regeneration status are met. If they are met, press the parking regeneration switch directly; otherwise, recheck.

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