CN112664331A

CN112664331A - Control method and device of engine

Info

Publication number: CN112664331A
Application number: CN202011510387.7A
Authority: CN
Inventors: 梁帅帅; 代子阳; 史彦晓
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-04-16
Anticipated expiration: 2040-12-18
Also published as: CN112664331B

Abstract

The invention provides a method and a device for controlling an engine, comprising the following steps: acquiring conventional parameters of an engine; acquiring a current engine mode of an engine body; calling a variable relation table corresponding to the engine mode according to the engine mode; and calculating based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and determining the required opening degree of the ETV valve. In the scheme, the required opening degree of the ETV valve is determined by calling the variable relation table corresponding to the engine mode of the current engine and calculating according to the conventional parameters of the engine and the control parameters corresponding to the conventional data in the variable relation table. The method for determining the required opening degree of the ETV valve can improve the heat management effect of the engine and the stability of exhaust control, and can improve the stability of engine exhaust treatment.

Description

Control method and device of engine

Technical Field

The invention relates to the technical field of engines, in particular to a control method and a control device of an engine.

Background

With the development of science and technology, automobiles are widely applied in daily life in the automobile industry, and when engine waste gas of the automobiles is directly discharged, the engine waste gas is treated by an after-treatment system so as to reduce the possibility that harmful gas in the engine waste gas reacts with oxygen in the air to generate gas causing air pollution.

At present, the opening of an exhaust throttle valve is often subjected to closed-loop regulation according to the exhaust temperature of an engine, so that the energy change of the exhaust of the engine is changed through the opening of the exhaust throttle valve, the control of exhaust temperature thermal management is achieved, and the exhaust treated by an aftertreatment system reaches the emission standard of the engine. Because the measurement of the exhaust temperature has certain delay, only closed-loop control can be adopted without distinguishing engine modes, and therefore when the engine is in a transient working condition, the effect of engine heat management and the stability of exhaust control are poor due to the fact that the opening of the exhaust throttle valve is determined in the mode, and the stability of engine exhaust treatment is further influenced.

Disclosure of Invention

In view of this, embodiments of the present invention provide a method and an apparatus for controlling an engine, so as to solve the problems in the prior art that the stability of exhaust gas control is poor and the stability of engine exhaust gas treatment is low due to the effect of engine thermal management.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

the embodiment of the invention discloses a control method of an engine in a first aspect, which is suitable for a control device of the engine, wherein the control device of the engine comprises an engine body, an engine pipeline, aftertreatment equipment, a pressure sensor, an exhaust throttle ETV valve and an electronic control unit ECU; the ECU is connected with the ETV valve, the engine body is connected with the engine pipeline, the ETV valve is arranged between the engine pipeline and the aftertreatment equipment, the pressure sensor is installed in front of the ETV valve, the ETV valve is used for controlling the exhaust flow flowing into the aftertreatment equipment, the pressure sensor is used for detecting the pressure in front of the ETV valve, and the method comprises the following steps:

acquiring conventional parameters of the engine, wherein the conventional parameters comprise engine speed, oil quantity calculated by pressure demand, temperature upstream of a diesel particulate trap (DPF), exhaust gas flow, intake air temperature and measured value of ETV pre-valve pressure;

acquiring current engine modes of the engine body, wherein the engine modes comprise a normal mode, an active/passive regeneration mode and a Selective Catalytic Reduction (SCR) heating mode;

calling a variable relation table corresponding to the engine mode according to the engine mode;

and calculating based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and determining the required opening degree of the ETV valve.

Optionally, the method further includes:

judging whether the required opening of the ETV valve reaches a preset required opening threshold value or not;

when the required opening of the ETV valve reaches a preset required opening threshold, determining that the current exhaust control mode is open-loop control;

and when the required opening of the ETV valve does not reach a preset required opening threshold value, determining that the current exhaust control mode is closed-loop control.

Optionally, the variable relation table includes a closed-loop pressure setting table, a feedforward opening setting table, an open-close loop oil amount upper limit setting table and an open-close loop oil amount lower limit setting table, the required opening of the ETV valve is determined based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and the variable relation table includes:

searching a closed-loop pressure setting table based on the engine speed and the oil quantity value corresponding to the demand pressure to obtain an initial ETV demand pressure;

correcting the initial ETV required pressure based on DPF pressure difference and inlet air temperature to determine ETV set pressure, wherein the DPF pressure difference is calculated according to the DPF upstream temperature and the exhaust gas flow;

searching a feedforward opening setting table based on the oil quantity value corresponding to the engine rotating speed and the demand pressure to obtain the feedforward opening of the ETV valve;

calculating according to the feedforward opening of the ETV valve, the ETV set pressure and the ETV pre-valve pressure measured value to obtain the calculated opening of the ETV valve;

respectively searching the open-close loop oil quantity upper limit setting table and the open-close loop oil quantity lower limit setting table by utilizing the rotating speed of the engine, and determining whether the oil quantity corresponding to the engine exceeds the oil quantity upper limit in the open-close loop oil quantity upper limit setting table and whether the oil quantity corresponding to the engine exceeds the oil quantity lower limit in the open-close loop oil quantity lower limit setting table;

when the oil amount exceeds the oil amount upper limit, taking the feed-forward opening degree of the ETV valve as the required opening degree of the ETV valve;

and when the oil amount is lower than the oil amount lower limit, taking the calculated opening degree of the ETV valve as the required opening degree of the ETV valve.

Optionally, the variable relation table further includes a DPF pressure difference table, an intake air temperature correction table, and a DPF pressure difference correction coefficient table, and the initial ETV demand pressure is corrected based on the DPF pressure difference and the intake air temperature, and the determining the ETV set pressure includes:

searching the DPF pressure difference table based on the DPF upstream temperature and the exhaust gas flow to obtain an initial DPF pressure difference;

searching the DPF pressure difference correction coefficient table based on the initial DPF pressure difference to obtain a pressure difference correction coefficient;

correcting the initial DPF pressure by using the differential pressure correction coefficient to obtain the DPF differential pressure;

searching the air inlet temperature correction table based on the air inlet temperature to obtain the corrected air inlet temperature;

correcting the initial ETV required pressure by using the DPF pressure difference and the corrected inlet air temperature to obtain corrected ETV required pressure;

determining an ETV set pressure based on the corrected ETV demand pressure.

Optionally, determining the ETV set pressure based on the corrected ETV demand pressure includes:

determining whether a difference between the corrected ETV demand pressure and the initial DPF differential pressure is greater than a first correction threshold, and whether a difference between the corrected ETV demand pressure and the initial DPF differential pressure is less than a second correction threshold, wherein the first correction threshold is greater than the second correction threshold;

if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is larger than a first correction threshold value, correcting the initial ETV required pressure by using the first correction threshold value to obtain an ETV set pressure;

if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a second correction threshold value, correcting the initial ETV required pressure by using the second correction threshold value to obtain an ETV set pressure;

and if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a first correction threshold and larger than a second correction threshold, determining the corrected ETV required pressure as the ETV set pressure.

Optionally, the calculating according to the feedforward opening of the ETV valve, the ETV set pressure, and the ETV pre-valve pressure measurement value to obtain the calculated opening of the ETV valve includes:

carrying out proportional, integral and differential PID (proportion integration differentiation) regulation on the difference value between the ETV set pressure and the ETV valve front pressure measurement value to obtain PID regulated ETV pressure;

and correcting the feedforward opening degree of the ETV valve based on the ETV pressure regulated by the PID to obtain the calculated opening degree of the ETV valve.

The embodiment of the invention discloses a control device of an engine, which comprises an engine body, an engine pipeline, an aftertreatment device, a pressure sensor, an exhaust throttle ETV valve and an electronic control unit ECU;

the ECU is connected with the ETV valve, and the engine body is connected with the engine pipeline;

the ETV valve is arranged between the engine pipeline and the aftertreatment equipment, the pressure sensor is installed in front of the ETV valve, the ETV valve is used for controlling the flow of exhaust flowing into the aftertreatment equipment, and the pressure sensor is used for detecting the pressure before the ETV valve;

the ECU is configured to: acquiring conventional parameters of the engine, wherein the conventional parameters comprise engine speed, oil quantity calculated by pressure demand, temperature upstream of a diesel particulate trap (DPF), exhaust gas flow, intake air temperature and measured value of ETV pre-valve pressure; acquiring current engine modes of the engine body, wherein the engine modes comprise a normal mode, an active/passive regeneration mode and a Selective Catalytic Reduction (SCR) heating mode; calling a variable relation table corresponding to the engine mode according to the engine mode; and calculating based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and determining the required opening degree of the ETV valve.

Optionally, the ECU is further configured to: judging whether the required opening of the ETV valve reaches a preset required opening threshold value or not; when the required opening of the ETV valve reaches a preset required opening threshold, determining that the current exhaust control mode is open-loop control; and when the required opening of the ETV valve does not reach a preset required opening threshold value, determining that the current exhaust control mode is closed-loop control.

Optionally, the variable relation table includes a closed-loop pressure setting table, a feedforward opening setting table, an open-close loop oil amount upper limit setting table and an open-close loop oil amount lower limit setting table, the ECU determining the required opening of the ETV valve is determined based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and is specifically configured to:

searching a closed-loop pressure setting table based on the engine speed and the oil quantity value corresponding to the demand pressure to obtain an initial ETV demand pressure; correcting the initial ETV required pressure based on DPF pressure difference and inlet air temperature to determine ETV set pressure, wherein the DPF pressure difference is calculated according to the DPF upstream temperature and the exhaust gas flow; searching a feedforward opening setting table based on the oil quantity value corresponding to the engine rotating speed and the demand pressure to obtain the feedforward opening of the ETV valve; calculating according to the feedforward opening of the ETV valve, the ETV set pressure and the ETV pre-valve pressure measured value to obtain the calculated opening of the ETV valve; searching an open-closed loop oil quantity upper limit setting table by using the engine rotation speed, determining whether the oil quantity corresponding to the engine exceeds the oil quantity upper limit in the open-closed loop oil quantity upper limit setting table, and searching an open-closed loop oil quantity lower limit setting table by using the engine rotation speed, and determining whether the oil quantity corresponding to the engine is lower than the oil quantity lower limit in the open-closed loop oil quantity lower limit setting table; when the oil amount exceeds the oil amount upper limit, taking the feed-forward opening degree of the ETV valve as the required opening degree of the ETV valve; and when the oil amount exceeds the oil amount lower limit, taking the calculated opening degree of the ETV valve as the required opening degree of the ETV valve.

In a third aspect of the embodiments of the present invention, an ECU for controlling an opening of an ETV valve is disclosed, the ECU including a processor and a memory, the memory storing therein a computer program, and the processor executing the computer program to implement the method for controlling an engine according to the first aspect of the embodiments of the present invention.

Based on the control method and the control device of the engine provided by the embodiment of the invention, the control device of the engine comprises an engine body, an engine pipeline, aftertreatment equipment, a pressure sensor, an exhaust throttle valve ETV valve and an electronic control unit ECU; the ECU is connected with an ETV valve, an engine body is connected with an engine pipeline, an ETV valve is arranged between the engine pipeline and an aftertreatment device, a pressure sensor is mounted in front of the ETV valve, the ETV valve is used for controlling the flow of exhaust gas flowing into the aftertreatment device, and the pressure sensor is used for detecting the pressure in front of the ETV valve, and the method comprises the following steps: acquiring conventional parameters of the engine, wherein the conventional parameters comprise engine speed, oil quantity calculated by required pressure, diesel particulate trap (DPF) upstream temperature, exhaust gas flow, intake air temperature and ETV (exhaust-to-combustion) valve pressure measured value; acquiring a current engine mode of an engine body, wherein the engine mode comprises a normal mode, an active/passive regeneration mode and a Selective Catalytic Reduction (SCR) heating mode; calling a variable relation table corresponding to the engine mode according to the engine mode; and calculating based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and determining the required opening degree of the ETV valve. In the embodiment of the invention, the required opening degree of the ETV valve is determined by calling the variable relation table corresponding to the engine mode of the current engine to calculate according to the conventional parameters of the engine and the control parameters corresponding to the conventional data in the variable relation table. The effect of engine thermal management and the stability of exhaust control can be improved, and the stability of engine exhaust treatment can be improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a control device of an engine according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart illustrating a method of controlling an engine according to an embodiment of the present invention;

FIG. 3 is a schematic flow chart diagram illustrating another engine control method provided by an embodiment of the present invention;

FIG. 4 is a schematic flow chart illustrating the process of determining the required opening of the ETV valve according to an embodiment of the present invention;

fig. 5 is a control logic diagram of the ECU in determining the required opening degree of the ETV valve according to the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

In the embodiment of the invention, the required opening degree of the ETV valve is determined by calling the variable relation table corresponding to the engine mode of the current engine to calculate according to the conventional parameters of the engine and the control parameters corresponding to the conventional data in the variable relation table. The effect of engine thermal management and the stability of exhaust control can be improved, and the stability of engine exhaust treatment can be improved.

Referring to fig. 1, a schematic structural diagram of a control device of an engine according to an embodiment of the present invention is provided, where the control device of the engine includes: engine block 10, engine conduit 20, aftertreatment device 30, pressure sensor 40, exhaust throttle ETV valve 50, and electronic control unit ECU 60.

The ECU60 is connected to the ETV valve 50, and the engine block 10 is connected to the engine pipe 20.

An ETV valve 50 is arranged between the engine pipeline 20 and the aftertreatment device 30, a pressure sensor 40 is mounted in front of the ETV valve 50, the ETV valve 50 is used for controlling the exhaust flow of the aftertreatment device 30, and the pressure sensor is used for detecting the pressure in front of the ETV valve 50.

With continued reference to fig. 1, the engine control apparatus further includes a supercharger 70 disposed in the engine pipe 20, the supercharger 70 being disposed in front of the pressure sensor 40, and an intercooler 80 being installed in the pipe between the supercharger and the engine body 10.

The engine duct 20 includes an intake pipe 21 and an exhaust pipe 22.

In a specific implementation, a compressor of the supercharger 70 is connected to the intake pipe 21, an intercooler 80 is installed between the supercharger and the intake pipe 21, and the intake pipe 21 is connected to the engine body 10 through the intercooler 80. The engine body 10 is connected to the turbine of the supercharger 70 through the exhaust pipe 22; the turbine of the booster 70 is connected to a pressure sensor 40 through the exhaust pipe 22, and the pressure sensor 40 detects the pressure before the ETV valve 50 to obtain a pressure measurement before the ETV valve 50.

The aftertreatment device 30 is provided with an Oxidation catalytic converter (DOC), a particulate trap DPF, and a rear selective catalytic reduction SCR + ammonia slip Catalyst ASC (not shown in the figure) in this order.

The ECU60 is configured to: acquiring conventional parameters of an engine; acquiring a current engine mode of the engine body 10; calling a variable relation table corresponding to the engine mode according to the engine mode; the required opening degree of the ETV valve 50 is determined by calculation based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table.

It is noted that the conventional parameters include engine speed, fuel quantity calculated from the required pressure, temperature upstream of the diesel particulate trap DPF, exhaust gas flow, intake air temperature, and ETV pre-valve pressure measurement; the engine modes include a Normal mode, an Rng _ Actv/Pasv active/passive regeneration mode, and an SCR _ Heat selective catalytic reduction SCR heating mode.

In the present invention, the required opening of the ETV valve is determined based on control parameters corresponding to conventional data in a variable map calibrated within the ECU60 when the engine 10 is in the different engine modes. A technician calibrates control parameters corresponding to different conventional parameters of the engine in different engine modes and writes the calibrated control parameters into an ECU, wherein the calibrated control parameters can be stored in a plurality of variable relation tables, namely graphs.

In a particular implementation, the ECU60 obtains in real time the current engine speed of the engine 10, the amount of oil calculated for the demand pressure, the temperature upstream of the diesel particulate trap DPF, the exhaust gas flow, the intake air temperature, and the ETV pre-valve pressure measurement. And acquiring the engine mode in which the engine body is currently located. And when the conventional parameters and the engine mode of the engine are obtained, determining a variable relation table corresponding to the engine mode according to the current engine mode of the engine. And searching a variable relation table according to the current conventional parameters, and determining the control parameters corresponding to the current conventional parameters. A calculation is made based on the conventional parameters and the control parameters to determine the required opening of the ETV valve 50.

It should be noted that the Normal mode corresponds to the variable relation table of the EOM (engine of model) engine mode EOM 0; the Rng _ Actv/Pasv active/passive regeneration mode corresponds to a variable relation table of the engine mode EOM 1; the SCR _ Heat Selective catalytic reduction SCR heating mode corresponds to a table of variables for the engine mode EOM 2.

The variable relation table comprises a closed-loop pressure setting table, a feedforward opening setting table, an opening-closing loop oil quantity upper limit setting table and an opening-closing loop oil quantity lower limit setting table.

In the embodiment of the invention, conventional parameters such as the current engine speed of the engine, the oil amount calculated by the required pressure, the temperature upstream of the diesel particulate trap DPF, the exhaust gas flow rate, the intake air temperature and the measured value of the pressure before the ETV valve are obtained, and the engine mode of the engine at the moment is determined. The required opening degree of the ETV valve is determined by calling a variable relation table corresponding to the engine mode of the current engine and calculating according to the conventional parameters of the engine and the control parameters corresponding to the conventional data in the variable relation table. The stability of engine exhaust treatment can be improved, and the effect of engine heat management can be improved when the engine carries out heat management.

Optionally, based on the control apparatus for an engine shown in the above-described embodiment of the present invention, the ECU60 is further configured to: judging whether the required opening degree of the ETV valve 50 reaches a preset required opening degree threshold value; when the required opening degree of the ETV valve 50 reaches a preset required opening degree threshold, determining that the current exhaust control mode is open-loop control; when the required opening degree of the ETV valve 50 does not reach the preset required opening degree threshold, it is determined that the current exhaust control mode is closed-loop control.

In a specific implementation, an exhaust control mode is determined by determining whether a required opening of the ETV valve is equal to a preset required opening threshold to ensure stable operation of the engine; when it is determined that the required opening degree of the ETV valve is equal to the preset required opening degree threshold, the open-loop control is employed to make the stability of the engine higher. When it is determined that the required opening of the ETV valve is less than or greater than the preset required opening threshold, the transient state is adjusted using closed-loop control to make the engine follow better. Thereby ensuring the stability of the engine.

The preset required opening degree threshold may be set in advance according to actual conditions, or may be set by a technician according to a plurality of experiments. Such as: may be set to 100%.

In the embodiment of the invention, conventional parameters such as the current engine speed of the engine, the oil amount calculated by the required pressure, the temperature upstream of the diesel particulate trap DPF, the exhaust gas flow rate, the intake air temperature and the measured value of the pressure before the ETV valve are obtained, and the engine mode of the engine at the moment is determined. The required opening degree of the ETV valve is determined by calling a variable relation table corresponding to the engine mode of the current engine and calculating according to the conventional parameters of the engine and the control parameters corresponding to the conventional data in the variable relation table. Furthermore, the stability of the engine exhaust treatment can be better improved by utilizing different exhaust control modes through different opening degrees of the ETV valve, and the effect of engine heat management can be improved when the engine is subjected to heat management.

Optionally, the ECU60 for determining the required opening degree of the ETV valve 50 based on the engine control apparatus shown in the above embodiment of the present invention, which calculates based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, is specifically configured to:

searching a closed-loop pressure setting table based on the oil mass value corresponding to the engine rotating speed and the demand pressure to obtain an initial ETV demand pressure; correcting the initial ETV required pressure based on the DPF pressure difference and the inlet air temperature, and determining the ETV set pressure; searching a feedforward opening setting table based on the oil mass value corresponding to the engine speed and the demand pressure to obtain the feedforward opening of the ETV valve 50; calculating according to the feedforward opening of the ETV valve 50, the ETV set pressure and the ETV pre-valve pressure measurement value to obtain the calculated opening of the ETV valve 50; searching an open-closed loop oil quantity upper limit setting table by using the engine rotation speed, determining whether the oil quantity corresponding to the engine 10 exceeds the oil quantity upper limit in the open-closed loop oil quantity upper limit setting table, searching an open-closed loop oil quantity lower limit setting table by using the engine rotation speed, and determining whether the oil quantity corresponding to the engine is lower than the oil quantity lower limit in the open-closed loop oil quantity lower limit setting table; when the oil amount exceeds the oil amount upper limit, taking the feed-forward opening degree of the ETV valve as the required opening degree of the ETV valve 50; when the oil amount is lower than the oil amount lower limit, the calculated opening degree of the ETV valve 50 is taken as the required opening degree of the ETV valve 50.

The DPF differential pressure is calculated from the DPF upstream temperature and the exhaust gas flow rate.

In the embodiment of the invention, aiming at each engine mode, the corresponding relation between the oil quantity value corresponding to the engine speed and the demand pressure as input and the initial ETV demand pressure as output is calibrated to generate a closed-loop pressure setting table; calibrating the corresponding relation between the oil quantity value corresponding to the engine speed and the demand pressure as input and the feedforward opening setting table as output to generate a feedforward opening setting table; calibrating the corresponding relation between the engine rotating speed as input and the oil quantity as output, marking the oil quantity upper limit corresponding to each engine rotating speed, and generating an open-closed loop oil quantity upper limit setting table; calibrating the corresponding relation between the engine rotating speed as input and the oil quantity as output, marking the oil quantity lower limit corresponding to each engine rotating speed, and generating an open-closed loop oil quantity lower limit setting table.

In a particular implementation, the ECU60 looks through a closed loop pressure map for an initial ETV demand pressure that matches an oil volume value corresponding to the engine speed and demand pressure. And determining the ETV set pressure by adding the DPF pressure difference and the initial ETV required pressure and multiplying the intake air temperature by the initial ETV required pressure corrected by the DPF pressure difference. Next, the feedforward opening setting table is searched for according to the oil amount values corresponding to the engine speed and the demand pressure, and the feedforward opening of the ETV valve 50 that matches the oil amount values corresponding to the engine speed and the demand pressure is obtained. Then, the calculated opening degree of the ETV valve 50 is calculated using the feed-forward opening degree of the ETV valve 50, the ETV set pressure, and the ETV pre-valve pressure measurement value.

Then, the ECU60 searches the open-close loop oil quantity upper limit setting table according to the engine rotation speed to obtain the oil quantity corresponding to the engine, and compares the oil quantity corresponding to the engine with the oil quantity upper limit in the open-close loop oil quantity upper limit setting table; searching an open-close loop oil quantity lower limit setting table according to the rotation speed of the engine to obtain the oil quantity corresponding to the engine, and comparing the oil quantity corresponding to the engine with the oil quantity lower limit in the open-close loop oil quantity lower limit setting table; if the amount of oil corresponding to the engine is greater than the upper limit of the amount of oil, the feed-forward opening of the ETV valve 50 is taken as the required opening of the ETV valve. If the amount of oil corresponding to the engine is less than the lower oil amount limit, the calculated opening of the ETV valve 50 is used as the required opening of the ETV valve.

In the embodiment of the invention, the current conventional parameters of the engine are obtained; searching a closed-loop pressure setting table by using the oil mass value corresponding to the engine rotating speed and the demand pressure to obtain the initial ETV demand pressure; correcting the initial ETV required pressure by using the DPF pressure difference and the air inlet temperature to determine the ETV set pressure; searching a feedforward opening setting table based on the oil quantity value corresponding to the engine rotating speed and the required pressure to obtain the feedforward opening of the ETV valve; so as to calculate according to the feedforward opening of the ETV valve, the ETV set pressure and the measured value of the pressure before the ETV valve, and obtain the calculated opening of the ETV valve; finally, determining whether the oil quantity exceeds an upper oil quantity limit or is lower than a lower oil quantity limit; when the oil amount exceeds the oil amount upper limit, taking the feedforward opening degree of the ETV valve as the required opening degree of the ETV valve; and when the oil amount is lower than the oil amount lower limit, taking the calculated opening degree of the ETV valve as the required opening degree of the ETV valve. The stability of engine exhaust treatment can be improved, and the effect of engine heat management can be improved when the engine carries out heat management.

Optionally, based on the engine control method shown in the above embodiment of the present invention, the ECU60 for determining the ETV set pressure by correcting the initial ETV required pressure based on the DPF pressure difference and the intake air temperature is specifically configured to: the DPF pressure differential table is looked up based on the DPF upstream temperature and exhaust flow to obtain an initial DPF pressure differential. And searching a DPF pressure difference correction coefficient table based on the initial DPF pressure difference to obtain a pressure difference correction coefficient. And correcting the initial DPF pressure by using the differential pressure correction coefficient to obtain the DPF differential pressure. And searching an air inlet temperature correction table based on the air inlet temperature to obtain the corrected air inlet temperature. And correcting the initial ETV required pressure by using the DPF pressure difference and the corrected inlet air temperature to obtain the corrected ETV required pressure. An ETV set pressure is determined based on the corrected ETV demand pressure.

In the embodiment of the invention, the corresponding relation between the DPF upstream temperature and the exhaust gas flow as input and the initial DPF pressure difference as output is calibrated for each engine mode, and a DPF pressure difference table is generated; calibrating the corresponding relation between the initial DPF pressure difference as input and the pressure difference correction coefficient as output to generate a DPF pressure difference correction coefficient table; the correspondence relationship between the intake air temperature as an input and the corrected intake air temperature as an output is calibrated, and an intake air temperature correction table is generated.

In a specific implementation, the ECU60 looks up the DPF pressure differential table based on the DPF upstream temperature and exhaust flow to obtain an initial DPF pressure differential. And searching a DPF pressure difference correction coefficient table according to the initial DPF pressure difference obtained by inquiring the DPF pressure difference table to obtain a pressure difference correction coefficient. And searching an air inlet temperature correction table according to the air inlet temperature to obtain the corrected air inlet temperature. And the corrected ETV required pressure is obtained by multiplying the corrected inlet air temperature by the corrected initial ETV required pressure of the DPF pressure difference by utilizing the DPF pressure difference and the initial ETV required pressure. Finally, an ETV set pressure is determined based on the corrected ETV demand pressure.

Optionally, the ECU60 for determining the ETV set pressure based on the corrected ETV required pressure is specifically configured to: judging whether the difference value between the corrected ETV required pressure and the initial DPF pressure difference is greater than a first correction threshold value or not, and whether the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a second correction threshold value or not, and correcting the initial ETV required pressure by using the first correction threshold value if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is greater than the first correction threshold value to obtain ETV set pressure; and if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a second correction threshold value, correcting the initial ETV required pressure by using the second correction threshold value to obtain the ETV set pressure.

In a specific implementation, the difference between the corrected ETV demand pressure and the initial DPF differential pressure is compared to a first correction threshold, and the difference between the corrected ETV demand pressure and the initial DPF differential pressure is compared to a second correction threshold; if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is larger than a first correction threshold value, indicating that the correction is overlarge, and adding the first correction threshold value to the initial ETV required pressure to obtain an ETV set pressure; if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a second correction threshold value, the correction is over-small, and the second correction threshold value is added with the initial ETV required pressure to obtain an ETV set pressure; if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a first correction threshold value and larger than a second correction threshold value, it is indicated that the correction is not too large or too small, and the corrected ETV required pressure is directly used as the ETV set pressure.

In the embodiment of the invention, the current conventional parameters of the engine are obtained; determining an initial ETV (electric transient voltage) demand pressure according to the oil quantity value corresponding to the engine speed and the demand pressure; determining the ETV set pressure through a DPF pressure difference meter, a DPF pressure difference correction coefficient meter and an air inlet temperature correction meter; determining a feed-forward opening degree of the ETV valve based on the oil quantity value corresponding to the engine speed and the demand pressure; so as to calculate according to the feedforward opening of the ETV valve, the ETV set pressure and the measured value of the pressure before the ETV valve, and obtain the calculated opening of the ETV valve; finally, determining whether the oil quantity exceeds an upper oil quantity limit or is lower than a lower oil quantity limit; when the oil amount exceeds the oil amount upper limit, taking the feedforward opening degree of the ETV valve as the required opening degree of the ETV valve; and when the oil amount is lower than the oil amount lower limit, taking the calculated opening degree of the ETV valve as the required opening degree of the ETV valve. The stability of engine exhaust treatment can be improved, and the effect of engine heat management can be improved when the engine carries out heat management.

Optionally, based on the control device of the engine shown in the above embodiment of the present invention, the ECU60, which obtains the calculated opening degree of the ETV valve by calculating according to the feed-forward opening degree of the ETV valve, the ETV set pressure, and the measured value of the pressure before the ETV valve, is specifically configured to: carrying out proportional, integral and differential PID (proportion integration differentiation) regulation on a difference value between the ETV set pressure and an ETV valve front pressure measurement value to obtain PID-regulated ETV pressure; and correcting the feedforward opening of the ETV valve based on the ETV pressure after PID adjustment to obtain the calculated opening of the ETV valve.

In specific implementation, the difference value between the ETV set pressure and the ETV valve front pressure measurement value is adjusted in a PID adjustment mode, and the ETV pressure after PID adjustment is obtained. And adding the ETV pressure after PID regulation to the feedforward opening degree of the ETV valve to obtain the calculated opening degree of the ETV valve.

It should be noted that PID control is a linear control law with proportional, integral and derivative functions.

In the embodiment of the invention, the difference value between the ETV set pressure and the ETV pre-valve pressure measurement value is adjusted in a PID (proportion integration differentiation) adjusting mode, and the ETV pressure after PID adjustment is corrected by utilizing the feedforward opening degree of the ETV valve, so that the calculated opening degree of the ETV valve is obtained. The stability of engine exhaust treatment can be improved, and the effect of engine heat management can be improved when the engine carries out heat management.

Based on the control device of the engine shown above, the embodiment of the present invention also discloses a control method of the engine, as shown in fig. 2, the control method of the engine shown in the embodiment of the present invention is applied to an ECU, and the method includes:

step S201: conventional parameters of the engine are obtained.

During step S201, the conventional parameters include the engine speed, the amount of oil calculated for the required pressure, the temperature upstream of the diesel particulate trap DPF, the exhaust gas flow rate, the intake air temperature, and the ETV pre-valve pressure measurement.

In the process of implementing step S201 specifically, the ECU acquires in real time the engine speed of the engine, the amount of oil calculated by the required pressure, the temperature upstream of the diesel particulate trap DPF, the exhaust gas flow rate, the intake air temperature, and the ETV pre-valve pressure measurement value.

It should be noted that the ETV pre-valve pressure measurement is measured by a pressure sensor in front of the ETV valve.

Step S202: the current engine mode of the engine body is obtained.

In step S202, the engine modes include a normal mode, an active/passive regeneration mode, and a selective catalytic reduction SCR heating mode.

In the process of implementing step S202 specifically, it is detected in real time that the engine mode in which the engine is currently located is a normal mode, an active/passive regeneration mode, or a selective catalytic reduction SCR heating mode.

Step S203: and calling a variable relation table corresponding to the engine mode according to the engine mode.

In the embodiment of the invention, when the engine is in different engine modes, the required opening degree of the ETV valve is determined according to the control parameters corresponding to the conventional data in the variable relation table calibrated in the ECU. A technician calibrates control parameters corresponding to different conventional parameters of the engine in different engine modes and writes the calibrated control parameters into an ECU, wherein the calibrated control parameters can be stored in a plurality of variable relation tables, namely graphs.

In the process of implementing step S203 specifically, the variable relation table corresponding to the current engine mode of the engine is determined according to the current engine mode. And searching a variable relation table according to the current conventional parameters, and determining the control parameters corresponding to the current conventional parameters.

The variable relation table includes a closed-loop pressure setting table, a feed-forward opening setting table, an open-close loop oil amount upper limit setting table, and an open-close loop oil amount lower limit setting table.

Further, the variable relation table further comprises a DPF pressure difference table, an intake air temperature correction table and a DPF pressure difference correction coefficient table.

Step S204: and calculating based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, and determining the required opening degree of the ETV valve.

In the process of specifically implementing step S204, conventional parameters and control parameters are used for calculation, and the required opening degree of the ETV valve is determined.

Based on the control method of the engine shown in fig. 2, referring to fig. 3 in combination with fig. 2, a flowchart of another control method of the engine shown in the embodiment of the invention is shown, and the method includes:

step S205: and judging whether the required opening of the ETV valve reaches a preset required opening threshold, executing a step S206 when the required opening of the ETV valve reaches the preset required opening threshold, and executing a step S207 when the required opening of the ETV valve does not reach the preset required opening threshold.

In embodiments of the present invention where different engine modes require different thermal management requirements, the required opening of the ETV valve may also vary. In order for the current thermal management requirements to be able to meet the engine steady operation, the current engine control mode needs to be determined by the required opening of the ETV valve. In the process of implementing step S205 specifically, the exhaust control mode is determined by determining whether the required opening of the ETV valve is equal to a preset required opening threshold value, so as to ensure stable operation of the engine; step S206 is performed when it is determined that the required opening degree of the ETV valve is equal to the preset required opening degree threshold, and step S207 is performed when it is determined that the required opening degree of the ETV valve is less than or greater than the preset required opening degree threshold.

The preset required opening degree threshold is set in advance according to actual conditions, or is set by a technician according to a plurality of experiments. Such as: may be set to 100%.

Step S206: it is determined that the current exhaust control mode is open-loop control.

In the process of implementing step S206 specifically, when the required opening degree of the ETV valve is equal to the preset required opening degree threshold, the open-loop control is adopted to make the stability of the engine higher.

Step S207: the current exhaust control mode is determined to be closed-loop control.

In the process of implementing step S207 specifically, when the required opening of the ETV valve is smaller than or larger than the preset required opening threshold, the transient state is adjusted by using the closed-loop control, so that the engine following performance is better. Thereby ensuring the stability of the engine.

Based on the engine control method shown in fig. 2, the variable relation table includes a closed-loop pressure setting table, a feedforward opening degree setting table, an open-close loop oil amount upper limit setting table, and an open-close loop oil amount lower limit setting table. In the process of performing the step S204 to determine the required opening degree of the ETV valve based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relation table, as shown in fig. 4, the method includes the following steps:

step S401: and searching a closed-loop pressure setting table based on the oil quantity value corresponding to the engine rotating speed and the demand pressure to obtain the initial ETV demand pressure.

In the process of specifically implementing step S401, the initial ETV demand pressure that matches the oil quantity value corresponding to the engine speed and the demand pressure is looked up through the closed-loop pressure setting table.

It should be noted that, for each engine mode, the correspondence between the oil amount values corresponding to the engine speed and the demand pressure as inputs and the initial ETV demand pressure as an output is calibrated to generate a closed-loop pressure map.

Step S402: the initial ETV demand pressure is corrected based on DPF differential pressure and intake air temperature to determine an ETV set pressure.

In step S402, the DPF differential pressure is calculated from the DPF upstream temperature and the exhaust gas flow rate.

In the process of implementing step S402, the ETV set pressure is determined by using the DPF differential pressure plus the initial ETV demand pressure, and then by using the intake air temperature multiplied by the corrected initial ETV demand pressure of the DPF differential pressure.

Step S403: and searching a feedforward opening setting table based on the oil quantity value corresponding to the engine rotating speed and the required pressure to obtain the feedforward opening of the ETV valve.

In the process of specifically implementing step S403, the feed-forward opening setting table is searched according to the oil amount values corresponding to the engine speed and the demand pressure, and the feed-forward opening of the ETV valve that matches the oil amount values corresponding to the engine speed and the demand pressure is obtained.

The feed-forward opening degree setting table is generated by calibrating the correspondence between the input oil amount value corresponding to the engine speed and the required pressure and the output feed-forward opening degree setting table for each engine mode.

Step S404: and calculating according to the feedforward opening of the ETV valve, the ETV set pressure and the measured value of the pressure before the ETV valve to obtain the calculated opening of the ETV valve.

In the process of specifically implementing step S404, the calculated opening degree of the ETV valve is calculated using the feed-forward opening degree of the ETV valve, the ETV set pressure, and the ETV pre-valve pressure measurement value.

Step S405: respectively searching an open-closed loop oil quantity upper limit setting table and an open-closed loop oil quantity lower limit setting table by utilizing the rotating speed of the engine, determining whether the oil quantity corresponding to the engine exceeds the oil quantity upper limit in the open-closed loop oil quantity upper limit setting table, and whether the oil quantity corresponding to the engine is lower than the oil quantity lower limit in the open-closed loop oil quantity lower limit setting table, executing a step S406 when the oil quantity exceeds the oil quantity upper limit, and executing a step S407 when the oil quantity is lower than the oil quantity lower limit.

In the process of specifically realizing the step S405, first, the upper limit oil amount setting table of the open-close loop oil setting ring is searched according to the engine rotation speed to obtain the oil amount corresponding to the engine, and the oil amount corresponding to the engine is compared with the upper limit oil amount in the upper limit oil amount setting table of the open-close loop oil setting ring; then, searching an open-close ring oil quantity lower limit setting table according to the rotation speed of the engine to obtain the oil quantity corresponding to the engine, and comparing the oil quantity corresponding to the engine with the oil quantity lower limit in the open-close ring oil quantity lower limit setting table; if the oil amount corresponding to the engine is greater than the upper oil amount limit, step S406 is executed, and if the oil amount corresponding to the engine is less than the lower oil amount limit, step S407 is executed.

And if the oil quantity corresponding to the engine is less than or equal to the upper oil quantity limit or the oil quantity corresponding to the engine is greater than the lower oil quantity limit, taking the feedforward opening degree of the ETV valve as the required opening degree of the ETV valve and the calculated opening degree of the ETV valve as the required opening degree of the ETV valve. And continues to acquire the engine speed of the engine.

The upper limit of the oil amount is larger than the lower limit of the oil amount.

And calibrating the corresponding relation between the engine rotating speed as input and the oil quantity as output aiming at each engine mode, and marking the oil quantity upper limit corresponding to each engine rotating speed so as to generate an open-closed loop oil quantity upper limit setting table.

And calibrating the corresponding relation between the engine rotating speed as input and the oil quantity as output aiming at each engine mode, marking the oil quantity lower limit corresponding to each engine rotating speed, and generating an open-close loop oil quantity lower limit setting table.

Step S406: the feed-forward opening degree of the ETV valve is taken as the required opening degree of the ETV valve.

In the process of implementing step S406 specifically, the feed-forward opening degree of the ETV valve is determined as the required opening degree of the ETV valve.

Step S407: the calculated opening degree of the ETV valve is taken as the required opening degree of the ETV valve.

In the process of embodying step S407, the calculated opening degree of the ETV valve is determined as the required opening degree of the ETV valve.

Based on the engine control method shown in fig. 4, the variable relation table further includes a DPF pressure difference table, an intake air temperature correction table, and a DPF pressure difference correction coefficient table, and the step S402 of correcting the initial ETV required pressure based on the DPF pressure difference and the intake air temperature and determining the ETV set pressure includes the steps of:

step S11: the DPF pressure differential table is looked up based on the DPF upstream temperature and exhaust flow to obtain an initial DPF pressure differential.

In the process of implementing step S11, the DPF pressure difference table is looked up according to the DPF upstream temperature and exhaust gas flow rate to obtain an initial DPF pressure difference.

Note that, for each engine mode, the correspondence between the DPF upstream temperature and exhaust gas flow rate as inputs and the initial DPF differential pressure as an output is calibrated to generate a DPF differential pressure table.

Step S12: and searching a DPF pressure difference correction coefficient table based on the initial DPF pressure difference to obtain a pressure difference correction coefficient.

In the process of implementing step S12, the DPF pressure difference correction coefficient table is looked up according to the initial DPF pressure difference obtained by looking up the DPF pressure difference table, so as to obtain the pressure difference correction coefficient.

Note that, for each engine mode, the correspondence between the initial DPF differential pressure as an input and the differential pressure correction coefficient as an output is calibrated to generate the DPF differential pressure correction coefficient table.

Step S13: and correcting the initial DPF pressure by using the differential pressure correction coefficient to obtain the DPF differential pressure.

In the process of implementing step S13, the DPF differential pressure is obtained by multiplying the initial DPF pressure by the differential pressure correction coefficient.

Step S14: and searching an air inlet temperature correction table based on the air inlet temperature to obtain the corrected air inlet temperature.

In step S14, the correspondence relationship between the intake air temperature as input and the corrected intake air temperature as output is calibrated for each engine mode to generate an intake air temperature correction table.

In the process of implementing step S14, the intake air temperature correction table is looked up according to the intake air temperature to obtain the corrected intake air temperature.

Step S15: and correcting the initial ETV required pressure by using the DPF pressure difference and the corrected inlet air temperature to obtain the corrected ETV required pressure.

In the process of implementing step S15 specifically, first, the corrected ETV demand pressure is obtained by adding the DPF differential pressure to the initial ETV demand pressure, and then multiplying the corrected intake air temperature by the corrected initial ETV demand pressure of the DPF differential pressure.

Step S16: an ETV set pressure is determined based on the corrected ETV demand pressure.

It should be noted that the process of executing step S16 includes the following steps:

step S21: judging whether the difference value between the corrected ETV required pressure and the initial DPF pressure difference is larger than a first correction threshold value or not, and whether the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a second correction threshold value or not, executing a step S22 if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is larger than the first correction threshold value, executing a step S23 if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than the second correction threshold value, and executing a step S24 if the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than the first correction threshold value and larger than the second correction threshold value.

In step S21, the first correction threshold is larger than the second correction threshold.

In embodiments of the present invention, there may be situations where the correction is too large or too small for the process of correcting the initial ETV demand pressure, thereby affecting the stability of the engine. In order to avoid too much or too little correction of the initial ETV demand pressure, further detection of the corrected ETV demand pressure is required. In the specific implementation of step S21, comparing the difference between the corrected ETV demand pressure and the initial DPF differential pressure with a first correction threshold, and comparing the difference between the corrected ETV demand pressure and the initial DPF differential pressure with a second correction threshold; if the difference between the corrected ETV demand pressure and the initial DPF differential pressure is greater than the first correction threshold, it is determined that the correction is too large, then step S22 is performed, if the difference between the corrected ETV demand pressure and the initial DPF differential pressure is less than the second correction threshold, it is determined that the correction is too small, step S23 is performed, if the difference between the corrected ETV demand pressure and the initial DPF differential pressure is less than the first correction threshold and greater than the second correction threshold, it is determined that the correction is not too large or too small, and step S24 is performed.

Step S22: and correcting the initial ETV required pressure by using the first correction threshold value to obtain the ETV set pressure.

In the specific implementation of step S22, the ETV set pressure is obtained by adding the initial ETV demand pressure to the first correction threshold.

Step S23: and correcting the initial ETV required pressure by using a second correction threshold value to obtain the ETV set pressure.

In the process of implementing step S23, the ETV set pressure is obtained by adding the initial ETV demand pressure to the second correction threshold.

Step S24: the corrected ETV demand pressure is determined as the ETV set pressure.

In the process of implementing step S24, the corrected ETV demand pressure is directly used as the ETV set pressure.

Based on the engine control method shown in fig. 4, in the step S404 of calculating according to the feedforward opening degree of the ETV valve, the ETV set pressure, and the ETV pre-valve pressure measurement value to obtain the calculated opening degree of the ETV valve, the method includes the following steps:

step S31: and carrying out PID (proportion integration differentiation) adjustment on the difference value between the ETV set pressure and the ETV valve front pressure measurement value to obtain the ETV pressure after PID adjustment.

In the process of specifically implementing the step S31, the difference between the ETV set pressure and the ETV pre-valve pressure measurement value is adjusted in a PID adjustment manner, so as to obtain the PID-adjusted ETV pressure.

Step S32: and correcting the feedforward opening of the ETV valve based on the ETV pressure after PID adjustment to obtain the calculated opening of the ETV valve.

In the process of specifically implementing step S32, the calculated opening degree of the ETV valve is obtained by adding the feed-forward opening degree of the ETV valve to the ETV pressure after the PID adjustment.

The process of determining the required opening of the ETV valve will be described in detail below with reference to an example.

Referring to fig. 5, a control logic diagram of the ECU in determining the required opening of the ETV valve.

As shown in fig. 5, assuming that the current engine mode is the normal mode, in the normal mode, a correspondence between the oil amount values corresponding to the engine speed and the demand pressure and the initial ETV demand pressure is obtained, and the correspondence between the oil amount values corresponding to the engine speed and the demand pressure as inputs and the initial ETV demand pressure as outputs is calibrated to generate a closed-loop pressure MAP ETV _ pdesbaseeom% _ MAP; acquiring the corresponding relation between the DPF upstream temperature and the exhaust gas flow rate and the initial DPF pressure difference, and calibrating the corresponding relation between the DPF upstream temperature and the exhaust gas flow rate as input and the initial DPF pressure difference as output to generate a DPF pressure difference table A1; acquiring the corresponding relation between the initial DPF pressure difference and the pressure difference correction coefficient, calibrating the corresponding relation between the initial DPF pressure difference as input and the pressure difference correction coefficient as output, and generating a DPF pressure difference correction coefficient table A2; the correspondence relationship between the intake air temperature and the corrected intake air temperature is acquired, and the correspondence relationship between the intake air temperature as an input and the corrected intake air temperature as an output is calibrated to generate an intake air temperature correction table B1.

With continued reference to FIG. 5, in the normal mode, a correspondence between oil mass values corresponding to engine speed and demand pressure and the feed-forward opening of the ETV valve is obtained, and the correspondence between oil mass values corresponding to engine speed and demand pressure as inputs and the feed-forward opening MAP as outputs is calibrated to generate the feed-forward opening MAP ETV _ rCtlBasEom% _ MAP. Acquiring a corresponding relation between the engine speed and the oil mass, calibrating the corresponding relation between the engine speed as input and the oil mass as output, and marking an oil mass upper limit corresponding to each engine speed to generate an open-closed loop oil mass upper limit setting table ETV _ GovOnEOM% _ CUR; calibrating the corresponding relation between the engine speed as input and the oil quantity as output, marking the oil quantity lower limit corresponding to each engine speed, and generating an open-closed loop oil quantity lower limit setting table ETV _ GovOffEOM% _ CUR.

The ECU obtains an engine speed Epm _ nEng of the engine, an oil quantity ETV _ qDesval calculated from the demand pressure, a temperature upstream of the diesel particulate trap DPF, an exhaust gas flow rate, an intake air temperature, and an ETV pre-valve pressure measurement value. The engine mode in which the engine is currently located is detected as a normal mode. According to the closed loop pressure setting table ETV _ pDesBasEom% _ MAP, the DPF pressure difference table A1, the DPF pressure difference correction coefficient table A2, the intake air temperature correction table B1, the feedforward opening degree setting table TV _ rCtlBasEom% _ MAP, the open-close loop oil amount upper limit setting table ETV _ GovOnEOM% _ CUR and the open-close loop oil amount lower limit setting table ETV _ GovOffEOM% _ CUR under the current normal mode of the engine.

The ECU looks through the closed loop pressure MAP ETV _ pdesbaseemom% _ MAP to find an initial ETV demand pressure that matches the fuel quantity value ETV _ qDesval corresponding to the engine speed Epm _ nEng and the demand pressure. Then, the DPF pressure difference table A1 is searched according to the DPF upstream temperature and the exhaust gas flow to obtain the initial DPF pressure difference, and the DPF pressure difference correction coefficient table A2 is searched according to the initial DPF pressure difference obtained by inquiring the DPF pressure difference table A1 to obtain the pressure difference correction coefficient. The DPF pressure difference is then obtained by multiplying the initial DPF pressure by a pressure difference correction factor. And searching an intake air temperature correction table B1 according to the intake air temperature to obtain the corrected intake air temperature. The corrected ETV demand pressure is obtained by using the DPF pressure difference and the initial ETV demand pressure, and then multiplying the corrected intake air temperature by the corrected initial ETV demand pressure of the DPF pressure difference.

And when the ECU determines that the difference value between the corrected ETV required pressure and the initial DPF pressure difference is smaller than a first correction threshold and larger than a second correction threshold, determining that the corrected ETV required pressure is not corrected too much or too little, and taking the corrected ETV required pressure as the ETV set pressure ETV _ P. And regulating the difference value between the ETV set pressure ETV _ P and the ETV valve front pressure measurement value in a PID regulation mode to obtain the ETV pressure after PID regulation. And searching a feedforward opening setting table ETV _ rCtlBasEom% _ MAP according to the oil quantity value ETV _ qDesval corresponding to the engine speed Epm _ nEng and the demand pressure to obtain the feedforward opening of the ETV valve matched with the oil quantity value corresponding to the engine speed and the demand pressure.

And when the ECU determines that the oil quantity corresponding to the engine exceeds the oil quantity upper limit in the open-close loop oil quantity upper limit setting table ETV _ GovOnEOM% _ CUR, determining the feedforward opening degree of the ETV valve as the required opening degree of the ETV valve. So that the ECU controls the ETV valve opening based on the required opening degree of the ETV valve.

In the embodiment of the invention, the required opening degree of the ETV valve is determined by calling the variable relation table corresponding to the engine mode of the current engine to calculate according to the conventional parameters of the engine and the control parameters corresponding to the conventional data in the variable relation table. The stability of the engine exhaust treatment can be improved.

An embodiment of the present invention further provides an ECU for controlling an opening of an ETV valve, where an Electronic Control Unit (ECU) is applied to a Control device of an engine, and the ECU includes: a processor and a memory.

The memory stores a computer program, and the processor is configured to execute the computer program stored in the memory to implement the control method of the engine shown above.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The control method of the engine is characterized by being applicable to a control device of the engine, wherein the control device of the engine comprises an engine body, an engine pipeline, an aftertreatment device, a pressure sensor, an exhaust throttle valve ETV valve and an electronic control unit ECU; the ECU is connected with the ETV valve, the engine body is connected with the engine pipeline, the ETV valve is arranged between the engine pipeline and the aftertreatment equipment, the pressure sensor is installed in front of the ETV valve, the ETV valve is used for controlling the exhaust flow flowing into the aftertreatment equipment, the pressure sensor is used for detecting the pressure in front of the ETV valve, and the method comprises the following steps:

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein the variable relationship table includes a closed-loop pressure setting table, a feed-forward opening degree setting table, an open-close loop oil amount upper limit setting table, and an open-close loop oil amount lower limit setting table, and wherein the determining the required opening degree of the ETV valve based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relationship table includes:

4. The method of claim 3 wherein said variable relationship table further comprises a DPF pressure differential table, an intake air temperature correction table, and a DPF pressure differential correction coefficient table, said initial ETV demand pressure being corrected based on DPF pressure differential and intake air temperature, determining an ETV set pressure comprising:

determining an ETV set pressure based on the corrected ETV demand pressure.

5. The method of claim 4, wherein determining an ETV set pressure based on the corrected ETV demand pressure comprises:

6. The method of claim 3, wherein said calculating a calculated opening of said ETV valve based on a feed-forward opening of said ETV valve, said ETV set pressure, and said ETV pre-valve pressure measurement comprises:

7. A control device of an engine, characterized by comprising an engine body, an engine pipe, an aftertreatment device, a pressure sensor, an exhaust throttle ETV valve, and an electronic control unit ECU;

8. The apparatus of claim 7, wherein the ECU is further configured to: judging whether the required opening of the ETV valve reaches a preset required opening threshold value or not; when the required opening of the ETV valve reaches a preset required opening threshold, determining that the current exhaust control mode is open-loop control; and when the required opening of the ETV valve does not reach a preset required opening threshold value, determining that the current exhaust control mode is closed-loop control.

9. The apparatus of claim 7, wherein the variable relationship table includes a closed-loop pressure setting table, a feed-forward opening degree setting table, an open-close loop oil amount upper limit setting table, and an open-close loop oil amount lower limit setting table, and the ECU determining the required opening degree of the ETV valve based on the conventional parameters and the control parameters corresponding to the conventional data in the variable relationship table is specifically configured to:

10. An ECU for controlling the opening of an ETV valve, characterized in that the ECU comprises a processor and a memory, the memory having stored therein a computer program, the processor executing the computer program to implement the control method of the engine according to claims 1 to 6.