An engine exhaust temperature control method and device during the regeneration of a particulate trap

Abstract

The embodiment of the present application discloses a method and device for controlling the exhaust temperature of an engine during the regeneration of a particulate trap. When the diesel particulate filter (DPF) is regenerated, the rotation speed and load of the vehicle engine are obtained, a preset air quantity and a preset intake pressure are set according to the rotation speed and load of the engine, the opening degree of the exhaust gas recirculation (EGR) system is controlled to be a first opening degree by the difference between the preset air quantity and the actual air quantity and the rotation speed, and the opening degree of the throttle valve is controlled to be a second opening degree by the difference between the preset intake pressure and the actual intake pressure and the rotation speed; wherein, the first opening degree and the second opening degree are used to control the difference between the post-turbine temperature of the engine exhaust gas and a preset temperature to be less than or equal to a preset threshold value. Based on the intake pressure of the air-fuel mixture entering the intake manifold of the engine and the amount of fresh air entering the intake manifold of the engine through the throttle valve, the decoupled control of the EGR and the throttle valve is realized, so that the exhaust temperature of the engine during DPF regeneration is more stable, and the DPF regeneration effect is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle control, and particularly to a method and device for controlling the exhaust temperature of an engine during the regeneration of a particulate filter. Background Art

[0002] A DPF (Diesel Particulate Filter) is a commonly used vehicle exhaust after-treatment device that can capture particulate matter (such as soot particles) in the exhaust gas, thereby achieving exhaust gas purification. When the amount of particulate matter captured by the DPF reaches a certain level, the exhaust temperature of the engine can be increased to cause the particulate matter captured in the DPF to burn and oxidize, thereby achieving the purpose of removing the particulate matter. The process of burning off the particulate matter in the DPF is called DPF regeneration. In the DPF regeneration mode, the exhaust temperature of the engine is usually increased by coordinating and adjusting EGR (Exhaust Gas Re-circulation), the throttle valve, and VGT (Variable geometry turbocharger). Among them, EGR recirculates part of the exhaust gas in the engine exhaust pipe back into the engine cylinder, reducing the temperature of the air-fuel mixture in the cylinder and achieving the purpose of reducing the content of nitrogen oxides in the engine exhaust gas.

[0003] In the related art, the EGR and the throttle valve in the DPF regeneration mode are controlled and output by a proportional-integral-derivative controller based on the deviation between the air quantity set value and the actual value. However, in such control methods, when the engine is in a low-load state, the throttle valve opening tends to be fully closed, and the EGR opening tends to be fully open. The fully open EGR opening causes excessive exhaust gas to circulate into the engine cylinder, affecting the combustion performance of the engine, causing the temperature of the air-fuel mixture in the cylinder to drop excessively, and at the same time increasing the content of particulate matter in the engine exhaust, resulting in poor DPF regeneration effect.

[0004] Therefore, how to improve the DPF regeneration effect urgently needs to be solved. Summary of the Invention

[0005] In order to solve the above technical problems, this application provides a method and device for controlling the exhaust temperature of an engine during the regeneration of a particulate filter, realizing the decoupled control of EGR and the throttle valve, thereby being able to better control the exhaust temperature of the engine during DPF regeneration and improving the DPF regeneration effect.

[0006] The embodiments of this application disclose the following technical solutions:

[0007] On the one hand, the embodiments of this application provide a method for controlling the exhaust temperature of an engine during the regeneration of a particulate filter, the method including:

[0008] Obtain the rotational speed and load of the vehicle engine;

[0009] Set a preset air volume and a preset intake pressure according to the rotational speed and load of the engine;

[0010] Calculate the difference between the preset air volume and the actual air volume as a first difference; the actual air volume is the content of fresh air entering the intake manifold of the engine through the throttle valve;

[0011] Control the opening degree of the exhaust gas recirculation system EGR as a first opening degree according to the first difference and the rotational speed;

[0012] Calculate the difference between the preset intake pressure and the actual intake pressure as a second difference; the actual intake pressure is the intake pressure of the air-fuel mixture entering the intake manifold of the engine, and the air-fuel mixture includes the fresh air entering the intake manifold of the engine through the throttle valve and the exhaust gas entering the intake manifold of the engine through the EGR;

[0013] Control the opening degree of the throttle valve as a second opening degree according to the second difference and the rotational speed;

[0014] Wherein, the first opening degree and the second opening degree are used to control the difference between the post-turbine temperature of the engine exhaust and the preset temperature to be less than or equal to a preset threshold value.

[0015] On the other hand, an embodiment of the present application provides an engine exhaust temperature control device during particulate filter regeneration, and the device includes an acquisition unit, a setting unit, a calculation unit, and a control unit:

[0016] The acquisition unit is used to acquire the rotational speed and load of the vehicle engine;

[0017] The setting unit is used to set a preset air volume and a preset intake pressure according to the rotational speed and load of the engine;

[0018] The calculation unit is used to calculate the difference between the preset air volume and the actual air volume as a first difference; the actual air volume is the content of fresh air entering the intake manifold of the engine through the throttle valve;

[0019] The control unit is used to control the opening degree of the exhaust gas recirculation system EGR as a first opening degree according to the first difference and the rotational speed;

[0020] The calculation unit is further used to calculate the difference between the preset intake pressure and the actual intake pressure as a second difference; the actual intake pressure is the intake pressure of the air-fuel mixture entering the intake manifold of the engine, and the air-fuel mixture includes the fresh air entering the intake manifold of the engine through the throttle valve and the exhaust gas entering the intake manifold of the engine through the EGR;

[0021] The control unit is further configured to control the opening degree of the throttle valve to be a second opening degree according to the second difference value and the rotational speed;

[0022] Wherein, the first opening degree and the second opening degree are used to adjust the difference between the post-turbine temperature of the engine exhaust gas and a preset temperature to be less than or equal to a preset threshold value.

[0023] It can be seen from the above technical solutions that a method for controlling the exhaust temperature of an engine during particulate filter regeneration provided by this application, during DPF regeneration, obtains the rotational speed and load of the vehicle engine, sets a preset air volume and a preset intake pressure according to the rotational speed and load of the engine, controls the opening degree of the exhaust gas recirculation system EGR to be a first opening degree through the difference between the preset air volume and the actual air volume and the rotational speed, and controls the opening degree of the throttle valve to be a second opening degree through the difference between the preset intake pressure and the actual intake pressure and the rotational speed; wherein, the first opening degree and the second opening degree are used to adjust the difference between the post-turbine temperature of the engine exhaust gas and a preset temperature to be less than or equal to a preset threshold value. Thus, based on the intake pressure parameter of the air-fuel mixture entering the intake manifold of the engine, the opening degree of the throttle valve is controlled. At the same time, based on the parameter of the content of fresh air entering the intake manifold of the engine through the throttle valve, the opening degree of the EGR is controlled, realizing the decoupled control of the EGR and the throttle valve, making the exhaust temperature of the engine during DPF regeneration more stable and improving the DPF regeneration effect. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic diagram of the intake and exhaust system layout of a diesel engine provided by an embodiment of the present application;

[0026] Figure 2 It is a method flow chart of a method for controlling the exhaust temperature of an engine during particulate filter regeneration provided by an embodiment of the present application;

[0027] Figure 3 It is a method for calculating the opening degree control of the EGR and the throttle valve during DPF regeneration provided by an embodiment of the present application;

[0028] Figure 4 It is a comparison diagram of the implementation effects of a method for controlling the exhaust temperature of an engine during particulate filter regeneration provided by an embodiment of the present application and the control method in the prior art;

[0029] Figure 5This is the device structure diagram of an engine exhaust temperature control device during the regeneration of a particulate trap provided by an embodiment of the present application. Detailed implementation manners

[0030] In order to enable those skilled in the art of the present technology to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0031] As a commonly used vehicle exhaust aftertreatment device, the DPF achieves exhaust gas purification by trapping particulate matter (such as soot particles) in the exhaust gas. When the accumulation of particulate matter reaches a certain amount, further treatment is required to remove the particulate matter. Otherwise, the exhaust back pressure of the engine is too high, affecting the performance of the engine. The process of removing the particulate matter in the DPF is called DPF regeneration. During DPF regeneration, the exhaust temperature of the engine can be increased through the coordinated adjustment of EGR, throttle valve, and VGT, that is, increasing the temperature of the engine exhaust gas, so that the particulate matter trapped in the DPF burns and oxidizes, thereby achieving the purpose of removal.

[0032] The inventors of the present application found that in the related art, the EGR and throttle valve during DPF regeneration are controlled and output by a proportional-integral-derivative (PID) controller based on the deviation between the set value and the actual value of the air volume under the engine operating conditions. This is a coupled control of the EGR and throttle valve, making it impossible to control the EGR and throttle valve more precisely and accurately, ultimately affecting the DPF regeneration effect. Especially when the engine is in a low-load operating condition and the air volume is in low demand, due to the strong coupling of the EGR and throttle valve controls, the throttle valve opening tends to be fully closed, and the EGR opening tends to be fully open. The fact that the EGR opening tends to be fully open causes excessive exhaust gas to circulate into the engine cylinder, affecting the combustion performance of the engine, causing the temperature of the air-fuel mixture in the cylinder to drop excessively while increasing the particulate matter content in the engine exhaust, affecting the DPF regeneration effect. In addition, when the engine is in a low-load operating condition, the content of nitrogen oxides in the engine exhaust is inherently low. Therefore, in such operating conditions, it should be controlled to reduce the EGR or close the EGR.

[0033] To this end, the embodiments of the present application provide an engine exhaust temperature control method and device during particulate filter regeneration. Based on the intake pressure of the air-fuel mixture entering the intake manifold of the engine, the opening degree of the throttle valve is controlled. At the same time, based on the content of fresh air passing through the throttle valve and entering the intake manifold of the engine, the opening degree of the EGR is controlled. Thus, decoupled control of the EGR and the throttle valve is achieved, such that when the engine is operating under low-load conditions, while controlling the reduction of the throttle valve opening degree, the reduction of the EGR opening degree can be controlled to achieve better engine exhaust temperature control during DPF regeneration.

[0034] In addition, the engine exhaust temperature control method and device provided by the embodiments of the present application utilize an existing intake pressure sensor in the engine intake and exhaust system. This sensor is disposed on the intake manifold of the engine and is used to collect the parameter signal of the intake pressure of the air-fuel mixture entering the engine. Therefore, for a vehicle, this solution does not require adding any hardware.

[0035] Specifically, it is described through the following embodiments:

[0036] Figure 1 FIG. is a schematic diagram of the layout of the intake and exhaust system of a diesel engine provided by the embodiments of the present application. Among them, 10 is an electronic control center, 11 is an engine, 12 is an EGR, 13 is a throttle valve, 14 is a DPF, 15 is a VGT, 16 is an intelligent sensor, 17 is an intake pressure sensor, 18 is a post-turbine temperature sensor, and 19 is an air filter. The electronic control center controls the opening degree of the throttle valve based on the intake pressure parameter collected by the intake pressure sensor, and controls the opening degree of the EGR based on the air volume parameter collected by the intelligent sensor. Thus, decoupled control of the throttle valve and the EGR is achieved, such that when the engine is operating under low-load conditions, while controlling the reduction of the throttle valve opening degree, the reduction of the EGR opening degree can be controlled to achieve better engine exhaust temperature control during DPF regeneration. Among them, the engine exhaust temperature is monitored by the post-turbine sensor.

[0037] It should be noted that the schematic diagram of the layout of the intake and exhaust system of a diesel engine provided by the embodiments of the present application is based on the typical layout of the existing diesel engine intake and exhaust system. It utilizes an existing intake pressure sensor in the engine intake and exhaust system, and through software, monitors the intake pressure parameter collected by this sensor to achieve independent control of the throttle valve, and further achieve decoupled control of the throttle valve and the EGR to achieve better engine exhaust temperature control during DPF regeneration, which is beneficial to DPF regeneration. At the same time, for a vehicle, no additional hardware cost is added.

[0038] Figure 2 FIG. is a flowchart of the method for controlling the engine exhaust temperature during particulate filter regeneration provided by the embodiments of the present application. The method includes:

[0039] S201: Obtain the rotational speed and load of the vehicle engine.

[0040] S202: Set a preset air quantity and a preset intake pressure according to the rotational speed and load of the engine.

[0041] The rotational speed and load of the vehicle engine represent the operating conditions of the engine. Since the amount of air required in the engine cylinder is different under different operating conditions, and in the embodiments of the present application, the throttle opening is controlled based on the parameter of intake pressure, therefore, the preset values of the two parameters need to be determined according to the specific operating conditions, that is, set the preset air quantity and the preset intake pressure according to the rotational speed and load of the engine.

[0042] S203: Calculate the difference between the preset air quantity and the actual air quantity as the first difference; the actual air quantity is the content of fresh air entering the intake manifold of the engine through the throttle valve.

[0043] S204: Control the opening degree of the exhaust gas recirculation system EGR as the first opening degree according to the first difference and the rotational speed.

[0044] Among them, the actual air quantity represents the content of fresh air entering the intake manifold of the engine through the throttle valve, which is collected by an intelligent sensor arranged on the intake manifold before the throttle valve; the preset air quantity is set according to the operating conditions of the engine. Calculate the difference between the preset air quantity and the actual air quantity as the first difference, and control the opening degree of the EGR as the first opening degree according to the first difference and the rotational speed of the engine.

[0045] In a possible implementation manner, according to the output result of the first controller through the first difference, determine the first output parameter, and then determine the first opening degree through the opening degree conversion MAP of the EGR according to the first output parameter and the rotational speed of the engine, and control the opening degree of the EGR as the first opening degree.

[0046] In another possible implementation manner, the first output parameter can also be determined in the following way: according to the output result of the first controller through the first difference and the feedforward term, determine the first output parameter. Specifically, perform a linear calculation on the output result of the first difference through the first controller and the feedforward term to determine the first output parameter. Among them, the feedforward term is determined by feedforward control according to the rotational speed and load of the engine. Specifically, the feedforward control MAP of the rotational speed and load of the engine can be called, and then the feedforward term is determined according to the rotational speed and load of the engine.

[0047] It should be noted that the first controller may be a proportional-integral-derivative (PID) controller, and the EGR opening conversion MAP and the feedforward control MAP of the engine speed and load may be pre-calibrated.

[0048] S205: Calculate the difference between the preset intake pressure and the actual intake pressure as the second difference.

[0049] S206: Control the opening of the throttle valve as the second opening according to the second difference and the engine speed.

[0050] Among them, the actual intake pressure is the intake pressure of the air-fuel mixture in the intake manifold of the engine, and the air-fuel mixture includes fresh air entering through the throttle valve and exhaust gas entering through the EGR; the preset intake pressure is set according to the operating conditions of the engine. Calculate the difference between the preset intake pressure and the actual intake pressure as the second difference, and control the opening of the throttle valve as the second opening according to the second difference and the engine speed.

[0051] In a possible implementation, according to the output result of the second controller through the second difference, determine the second output parameter, and then determine the second opening according to the second output parameter and the engine speed through the throttle valve opening conversion MAP, and control the opening of the throttle valve as the second opening.

[0052] In another possible implementation, the second output parameter can also be determined in the following way: determine the second output parameter according to the output result of the second controller through the second difference and the feedforward term. Specifically, perform a linear calculation on the output result of the second difference through the second controller and the feedforward term to determine the second output parameter. Among them, the feedforward term is determined by feedforward control according to the engine speed and load. Specifically, the feedforward control MAP of the engine speed and load can be called, and then the feedforward term can be determined according to the engine speed and load.

[0053] It should be noted that the second controller may be a proportional-integral-derivative (PID) controller, and the throttle valve opening conversion MAP and the feedforward control MAP of the engine speed and load may be pre-calibrated.

[0054] Among them, the first opening degree and the second opening degree are used to control the difference between the temperature after the turbine of the engine exhaust gas and a preset temperature to be less than or equal to a preset threshold. Specifically, based on the first difference, the EGR is independently controlled by a first controller, and based on the second difference, the throttle valve is independently controlled by a second controller, so as to achieve decoupled control of the EGR and the throttle valve, and avoid high-frequency fluctuations or low-frequency oscillations of the air mass flow and the intake pressure. By controlling the opening degree of the EGR to be the first opening degree and the opening degree of the throttle valve to be the second opening degree, the difference between the temperature after the turbine of the engine exhaust gas and the preset temperature is less than or equal to the preset threshold under the current operating conditions of the engine, that is, a more stable engine exhaust temperature is obtained. Among them, the temperature after the turbine of the engine exhaust gas can be collected by a temperature sensor after the turbine arranged on the engine exhaust manifold.

[0055] In another possible implementation manner, before determining the first output parameter, the PID parameter selection direction can also be determined based on the first difference, and the control parameters of the first controller are determined according to the parameter selection direction, the engine speed and the load, where the PID parameter selection direction determined based on the first difference indicates the speed of controlling the EGR component to act; before determining the second output parameter, the PID parameter selection direction can also be determined based on the second difference, and the control parameters of the second controller are determined according to the parameter selection direction, the engine speed and the load, where the PID parameter selection direction determined based on the second difference indicates the speed of controlling the throttle valve component to act. Specifically, the PID parameter correction MAP can be called to determine according to the parameter selection direction, the engine speed and the load.

[0056] This is because during the entire DPF regeneration process, a more stable engine exhaust temperature is achieved through the coordinated control of the EGR, the throttle valve and the VGT. The three are highly correlated during the control process. Even if separate PID controllers are used to control the actuators of the three in the control strategy, the weights of the components' impacts on the air volume, the intake pressure and the boost pressure need to be considered when selecting the controller parameters to avoid problems such as high-frequency jitter or low-frequency oscillation of the system. It should be noted that the boost pressure is a parameter used to control the VGT. However, since this application does not make improvements to the control part of the VGT, the control method of the VGT is not described in detail here.

[0057] Specifically, the speeds of controlling the component actions from fast to slow are defined as: the throttle valve fully open direction, the EGR closed direction, the EGR opening direction, the throttle valve closed direction, and the turbocharger control.

[0058] Such as Figure 3As shown, it is a method for calculating the opening control of EGR and throttle during DPF regeneration provided by an embodiment of the present application. It can be understood that for specific descriptions, reference can be made to the above descriptions of S203 - S206. Among them, the air quantity deviation is the first difference, and the intake pressure deviation is the second difference; the EGR opening is the first opening, and the throttle opening is the second opening.

[0059] It should be noted that Figure 3 The switch selection shown is set by the inventor of the present application from the perspective of engineering implementation, aiming to retain the original control strategy. That is to say, the control of the throttle can be achieved not only based on the parameter of intake pressure but also based on the parameter of air quantity. Specifically, it can be selected according to the current operating condition of the engine. For example, when the engine is operating under low load, the control of the throttle is achieved based on the parameter of intake pressure.

[0060] Figure 4 It is a comparison chart of the implementation effects of an engine exhaust temperature control method during particulate filter regeneration provided by an embodiment of the present application and the control method in the prior art. It is a comparative experiment conducted by the inventor of the present application to test the implementation effect of the control method described in the present application. It can be seen that: by using the control method described in the present application, under the transient test cycle (World Harmonized Transient Cycle, WHTC), the air quantity, boost pressure, and intake pressure can follow the set value in a timely manner, and the most obvious manifestation is on the post - turbine temperature of the engine exhaust, as Figure 4 shown in the implementation effect. The engine exhaust temperature control method described in the present application can make the engine exhaust temperature more stable, which is more beneficial for DPF regeneration.

[0061] Figure 5 It is a device structure diagram of an engine exhaust temperature control device during particulate filter regeneration provided by an embodiment of the present application. The device includes an acquisition unit 501, a setting unit 502, a calculation unit 503, and a control unit 504:

[0062] The acquisition unit 501 is used to acquire the speed and load of the vehicle engine;

[0063] The setting unit 502 is used to set a preset air quantity and a preset intake pressure according to the speed and load of the engine;

[0064] The calculation unit 503 is used to calculate the difference between the preset air quantity and the actual air quantity as the first difference; the actual air quantity is the content of fresh air entering the intake manifold of the engine through the throttle.

[0065] The control unit 504 is configured to control the opening degree of the exhaust gas recirculation system EGR to a first opening degree according to the first difference and the rotational speed;

[0066] The calculation unit 503 is further configured to calculate the difference between the preset intake pressure and the actual intake pressure as a second difference; the actual intake pressure is the intake pressure of the air-fuel mixture in the intake manifold of the engine, and the air-fuel mixture includes fresh air entering the intake manifold of the engine through the throttle valve and exhaust gas entering the intake manifold of the engine through the EGR;

[0067] The control unit 504 is further configured to control the opening degree of the throttle valve to a second opening degree according to the second difference and the rotational speed;

[0068] Wherein, the first opening degree and the second opening degree are used to regulate the difference between the post-turbine temperature of the engine exhaust gas and the preset temperature to be less than or equal to a preset threshold value.

[0069] In a possible implementation manner, the device further includes a determination unit:

[0070] The determination unit is configured to determine a first output parameter according to the output result of the first controller through the first difference;

[0071] The determination unit is further configured to determine the first opening degree according to the first output parameter and the rotational speed through the opening degree conversion MAP of the EGR;

[0072] The determination unit is further configured to determine a second output parameter according to the output result of the second controller through the second difference;

[0073] The determination unit is further configured to determine the second opening degree according to the second output parameter and the rotational speed through the opening degree conversion MAP of the throttle valve;

[0074] Then, the control unit is further configured to control the opening degree of the EGR to the first opening degree; the control unit is further configured to control the opening degree of the throttle valve to the second opening degree.

[0075] In another possible implementation manner, the determination unit is further configured to determine a feedforward term by using feedforward control according to the rotational speed and load of the engine;

[0076] Then, the determination unit is further configured to determine the first output parameter according to the output result of the first controller through the first difference and the feedforward term;

[0077] The determination unit is further configured to determine the second output parameter according to the output result of the second controller through the second difference and the feedforward term.

[0078] In yet another possible implementation, the determining unit is further configured to determine control parameters of the first controller according to the rotational speed and load of the engine and the first difference;

[0079] The determining unit is further configured to determine control parameters of the second controller according to the rotational speed and load of the engine and the second difference.

[0080] It can be seen that during the DPF regeneration of the vehicle, the rotational speed and load of the vehicle engine are obtained, a preset air quantity and a preset intake pressure are set according to the rotational speed and load of the engine, the opening degree of the exhaust gas recirculation system EGR is controlled to be a first opening degree by the difference between the preset air quantity and the actual air quantity and the rotational speed, and the opening degree of the throttle valve is controlled to be a second opening degree by the difference between the preset intake pressure and the actual intake pressure and the rotational speed; wherein, the first opening degree and the second opening degree are used to control the difference between the post-turbine temperature of the engine exhaust gas and the preset temperature to be less than or equal to a preset threshold. Thus, based on the intake pressure parameter of the air-fuel mixture entering the intake manifold of the engine, the opening degree of the throttle valve is controlled. At the same time, based on the parameter of the content of fresh air entering the intake manifold of the engine through the throttle valve, the opening degree of the EGR is controlled, realizing the decoupled control of the EGR and the throttle valve, making the engine exhaust temperature more stable during DPF regeneration and improving the DPF regeneration effect.

[0081] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0082] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0083] The above has introduced in detail a method and device for controlling the exhaust gas temperature of an engine during the regeneration of a particulate trap. In this text, specific examples are used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method of the present application. At the same time, for those of ordinary skill in the art, according to the method of the present application, there will be changes in the specific implementation manner and application scope.

[0084] In summary, the content of this specification should not be construed as a limitation on the present application. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Moreover, on the basis of the implementation manners provided in the above aspects of the present application, further combinations can be made to provide more implementation manners. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An engine exhaust temperature control method during the regeneration of a particulate trap, characterized in that The method includes: Obtaining the rotational speed and load of the vehicle engine; Setting a preset air quantity and a preset intake pressure according to the rotational speed and load of the engine; Calculating the difference between the preset air quantity and the actual air quantity as a first difference; the actual air quantity is the content of fresh air entering the intake manifold of the engine through the throttle valve; Controlling the opening degree of the exhaust gas recirculation system EGR as a first opening degree according to the first difference and the rotational speed; Calculating the difference between the preset intake pressure and the actual intake pressure as a second difference; the actual intake pressure is the intake pressure of the air-fuel mixture entering the intake manifold of the engine, and the air-fuel mixture includes the fresh air entering the intake manifold of the engine through the throttle valve and the exhaust gas entering the intake manifold of the engine through the EGR; Controlling the opening degree of the throttle valve as a second opening degree according to the second difference and the rotational speed; Wherein, the first opening degree and the second opening degree are used to control the difference between the post-turbine temperature of the engine exhaust and a preset temperature to be less than or equal to a preset threshold; and when the load of the engine indicates an operating condition of the engine in a low-load state, the first opening degree is used to indicate a reduction in the opening degree of the EGR, and the second opening degree is used to indicate a reduction in the opening degree of the throttle valve.

2. The method according to claim 1, wherein The controlling the opening degree of the exhaust gas recirculation system EGR as a first opening degree according to the first difference and the rotational speed includes: Determining a first output parameter according to the output result of a first controller based on the first difference; Determining the first opening degree according to the first output parameter and the rotational speed through an opening degree conversion MAP of the EGR; Controlling the opening degree of the EGR as the first opening degree.

3. The method according to claim 2, characterized in that It further includes: Determining a feedforward term by using feedforward control according to the rotational speed and load of the engine; Then, the determining the first output parameter according to the output result of the first controller based on the first difference includes: determining the first output parameter according to the output result of the first controller based on the first difference and the feedforward term.

4. The method according to any one of claims 2-3, characterized in that It further includes: Determining the control parameter of the first controller according to the rotational speed and load of the engine and the first difference.

5. The method according to any one of claims 2 - 3, characterized in that, The first controller is a proportional-integral-derivative controller.

6. The method according to claim 1, characterized in that, The controlling the opening degree of the throttle valve as a second opening degree according to the second difference and the rotational speed includes: Determining a second output parameter according to the output result of a second controller based on the second difference; Determining the second opening degree according to the second output parameter and the rotational speed through an opening degree conversion MAP of the throttle valve; Controlling the opening degree of the throttle valve as the second opening degree.

7. The method according to claim 6, wherein It further includes: Determining a feedforward term by using feedforward control according to the rotational speed and load of the engine; Then, the determining the second output parameter according to the output result of the second controller based on the second difference includes: determining the second output parameter according to the output result of the second controller based on the second difference and the feedforward term.

8. The method according to any one of claims 6-7, characterized in that, It further includes: Determining the control parameter of the second controller according to the rotational speed and load of the engine and the second difference.

9. The method according to any one of claims 6-7, characterized in that, The second controller is a proportional-integral-derivative controller.

10. An engine exhaust gas temperature control device during the regeneration of a particulate trap, characterized in that, The device includes an acquisition unit, a setting unit, a calculation unit, and a control unit: The acquisition unit is configured to acquire the rotational speed and load of the vehicle engine; The setting unit is configured to set a preset air quantity and a preset intake pressure according to the rotational speed and load of the engine; The calculation unit is configured to calculate the difference between the preset air quantity and the actual air quantity as a first difference; The actual air quantity is the content of fresh air entering the intake manifold of the engine through the throttle valve; The control unit is configured to control the opening degree of the exhaust gas recirculation system EGR as a first opening degree according to the first difference and the rotational speed; The calculation unit is further configured to calculate the difference between the preset intake pressure and the actual intake pressure as a second difference; the actual intake pressure is the intake pressure of the air-fuel mixture entering the intake manifold of the engine, and the air-fuel mixture includes the fresh air entering the intake manifold of the engine through the throttle valve and the exhaust gas entering the intake manifold of the engine through the EGR; The control unit is further configured to control the opening degree of the throttle valve as a second opening degree according to the second difference and the rotational speed; Wherein, the first opening degree and the second opening degree are used to control the difference between the temperature after the turbine of the engine exhaust and the preset temperature to be less than or equal to a preset threshold; and when the load of the engine indicates an operating condition of the engine in a low load state, the first opening degree is used to indicate a decrease in the opening degree of the EGR, and the second opening degree is used to indicate a decrease in the opening degree of the throttle valve.

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