CN112360635A - Supercharging pressure control method for improving EGR rate - Google Patents

Supercharging pressure control method for improving EGR rate Download PDF

Info

Publication number
CN112360635A
CN112360635A CN202011245594.4A CN202011245594A CN112360635A CN 112360635 A CN112360635 A CN 112360635A CN 202011245594 A CN202011245594 A CN 202011245594A CN 112360635 A CN112360635 A CN 112360635A
Authority
CN
China
Prior art keywords
boost pressure
state
boost
pressure
increment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202011245594.4A
Other languages
Chinese (zh)
Other versions
CN112360635B (en
Inventor
秦龙
刘磊
赵宁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dongfeng Motor Corp
Original Assignee
Dongfeng Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dongfeng Motor Corp filed Critical Dongfeng Motor Corp
Priority to CN202011245594.4A priority Critical patent/CN112360635B/en
Publication of CN112360635A publication Critical patent/CN112360635A/en
Application granted granted Critical
Publication of CN112360635B publication Critical patent/CN112360635B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0002—Controlling intake air
    • F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D23/00—Controlling engines characterised by their being supercharged
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)

Abstract

The invention discloses a boost pressure control method for improving an EGR (exhaust gas Recirculation) rate, which comprises the following steps of: determining an initial maximum boost pressure increase according to the target fresh air intake density of the engine and the actual rotating speed of the engine; setting a supercharging pressure increment change rate according to the allowable fluctuation range of power fluctuation, and performing transition processing on the initial maximum supercharging pressure increment by combining a supercharging pressure increment control state to obtain the final requested maximum supercharging pressure increment; based on the final requested maximum boost pressure increase, the final actual requested boost pressure increase is obtained by the feed-forward portion plus the accumulation control portion, which is limited between 0 and the final requested maximum boost pressure increase. The supercharging pressure control method for improving the EGR rate considers the working condition that the supercharging pressure needs to be increased in the EGR control, reasonably calculates the final target supercharging pressure value, gradually and transitionally improves the supercharging pressure, avoids the fluctuation of power output, ensures that the oil consumption is not increased, and obviously improves the EGR control.

Description

Supercharging pressure control method for improving EGR rate
Technical Field
The invention belongs to the technical field of engines, and particularly relates to a boost pressure control method for improving an EGR rate.
Background
With the rapid development of the automobile and internal combustion engine industry, the problems of energy demand and environmental protection become difficult problems in all countries in the world at present, so that energy conservation and emission reduction become two major topics for the development of the internal combustion engine industry. In the aspect of energy conservation, automobile manufacturers at home and abroad use the following components: the technology of Otto (Otto) circulation, Atkinson (Atkinson) circulation, Miller (Miller) circulation, high-pressure Exhaust Gas Recirculation (EGR) or low-pressure high-pressure Exhaust Gas Recirculation and the like improves the combustion working process of the engine, or reduces the pumping loss of medium and small loads through the miniaturization design of the engine, and improves the fuel economy of the traditional gasoline engine.
Turbocharged engines may include Exhaust Gas Recirculation (EGR), which may take exhaust gas from the exhaust gas into the intake system. Research shows that the EGR system has certain advantages in improving emission, reducing oil consumption and improving anti-knock capability.
However, in the EGR control, when the difference between the EGR control valve inlet gas pressure (exhaust pressure) and the EGR control valve outlet gas pressure (intake manifold intake pressure) is small or even negative, the EGR exhaust gas flow rate is small or a phenomenon of gas backflow occurs.
Disclosure of Invention
The invention aims to provide a boost pressure control method for improving an EGR rate, and solves the problem that when the difference between the gas pressure at an inlet of an EGR control valve and the gas pressure at an outlet of the EGR control valve is small or even negative, the flow of EGR waste gas is small or gas flows backwards.
The invention provides a boost pressure control method for improving an EGR (exhaust gas recirculation) rate, which comprises the following steps of:
s1, determining an initial maximum boost pressure increment according to the target fresh air intake density of the engine and the actual rotating speed of the engine;
s2, setting a boost pressure increment change rate according to the allowable fluctuation range of the power fluctuation, wherein the boost pressure increment increase change rate and the boost pressure increment decrease change rate are included; obtaining the increment and the decrement of the boost pressure increment according to the change rate of the boost pressure increment, and performing transition processing on the initial maximum boost pressure increment by combining the control state of the boost pressure increment to obtain the final requested maximum boost pressure increment;
s3, determining a feed-forward part according to the target fresh air intake density of the engine and the actual rotating speed of the engine; acquiring an accumulation control part according to the supercharging pressure increment control state; obtaining a final actually requested boost pressure increase, which is limited between 0 and the final requested maximum boost pressure increase, by the feed-forward portion plus the accumulation control portion, based on the final requested maximum boost pressure increase; and finally, accumulating the final actually requested boost pressure increment to the target boost pressure of the boost control to obtain the final target boost pressure for the boost control.
Further, in step S2, in combination with the boost pressure increment control state, performing transition processing on the initial maximum boost pressure increment to obtain the final requested boost pressure increment specifically includes:
s21, when the EGR state is changed from the non-activated state to the activated state and the maximum value of the pressure difference between the supercharging pressure increment and the front and back of the throttle valve is smaller than the initial maximum supercharging pressure increment, the control state is set to be a Ramp Up state; judging the control state of the previous sampling period, and if the control state of the previous sampling period is not in a Ramp Up state, maintaining the boost pressure increment at the current value; if the control state of the previous sampling period is in a Ramp Up state, determining the previous boost pressure increment plus the boost pressure increment as the current boost pressure increment;
if the maximum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve is smaller than the initial maximum boost pressure increment, the Ramp Up state is maintained in the control state; taking the maximum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve as the final requested maximum boost pressure increment in the Ramp Up state;
s22, changing the control state from the Ramp Up state to the Active state until the maximum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve exceeds the initial maximum boost pressure increment;
s23, when the EGR state is changed from the Active state to the inactive state, the control state is changed from the Active state to the Ramp Down state; determining the last boost pressure increment plus the boost pressure increment decrease as the current boost pressure increment;
if the minimum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve is larger than 0, the Ramp Down state is maintained in the control state; taking the finally requested boost pressure increment in the Ramp Down state as the current boost pressure increment;
s24, changing the control state from the Ramp Down state to the Off state until the minimum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve is less than or equal to 0, and finally taking the requested maximum boost pressure increment as 0;
further, the step S3 of obtaining the accumulation control portion according to the boost pressure increment control state specifically includes:
s31, when the boost pressure increment control state is an Off state, the accumulative control part is 0;
s32, when the supercharging pressure increment control state is not the Off state, the accumulation control portion obtains the following method:
s321, determining an optimal EGR control valve outlet and inlet exhaust gas target pressure ratio according to the engine target fresh air intake density and the engine actual rotating speed, subtracting the optimal EGR control valve outlet and inlet exhaust gas target pressure ratio from the EGR control valve actual pressure ratio to obtain a pressure ratio difference, and calculating the change rate of the pressure ratio difference;
s322, determining the accumulated change rate of the accumulation control part according to the pressure ratio difference and the pressure ratio difference change rate;
and S323, obtaining an accumulation control part according to the accumulation change rate of the accumulation control part and a calculation formula of the accumulation control part.
Further, the accumulation control part calculates the formula as:
pBoostDeltaReqIPart(n+1)＝pBoostDeltaReqIPart(n)+
pBoostDeltaReqIPartGain(n+1)×Δt×(rEGRValvePresRatioErr(n+1)-kBoostWindUpGain×pBoostDeltaSatu(n+1))
in the formula, pBoostDeltaReqIPartIndicating an accumulation control part, pBoostDeltaReqIPartGainIndicating the accumulated rate of change of the accumulation control section, at indicating a time interval, rEGRValvePresRatioErrIndicating the pressure ratio difference, kBoostWindUpGainRepresenting inverse integral saturation coefficient, pBoostDeltaSatuIndicating the integrated saturated boost pressure, and n, n +1 indicating the sampling period number.
Further, the calculation formula of the integrated saturated boost pressure is:
pBoostDeltaSatu(n+1)＝pBoostDeltaReq(n)-[pBoostDeltaReqFF(n)+pBoostDeltaReqIPart(n)]
in the formula, pBoostDeltaReqIndicating the final requested boost pressure increase, pBoostDeltaReqFFDenotes the feedforward portion, pBoostDeltaReqIPartThe accumulation control section is shown.
The invention has the beneficial effects that: according to the boost pressure control method for improving the EGR rate, the working condition that boost pressure needs to be increased in EGR control is considered, the final target boost pressure value is reasonably calculated, the boost pressure is gradually increased in a transitional mode, power output fluctuation is avoided, oil consumption is guaranteed not to be increased, and EGR control is remarkably improved.
Drawings
FIG. 1 is a flow chart of a boost pressure control method of the present invention to improve EGR rate;
FIG. 2 is a control flow diagram when EGR is transitioned from an inactive state to an active state;
fig. 3 is a control flowchart when the EGR state is changed from the active state to the inactive state.
Detailed Description
The invention will be further described with reference to the accompanying drawings in which:
when the difference between the EGR control valve inlet gas pressure (exhaust pressure) and the EGR control valve outlet gas pressure (intake manifold intake pressure) is small or even negative, the EGR exhaust gas flow rate is small or a gas backflow phenomenon occurs. In order to avoid the occurrence of the EGR rate control abnormality due to this phenomenon, in the case of the exhaust turbocharged engine, the boost pressure may be increased by increasing the boost pressure. The purpose of the treatment is as follows: 1. more exhaust gas flow after the combustion of the engine is used for pushing a supercharger turbine, and at the moment, exhaust gas is blocked, and the exhaust pressure is increased, so that the pressure difference on two sides of the EGR control valve is increased; 2. the pressure difference between the front and the back of the throttle valve is increased, and the gas diversion is better realized. When the boost pressure is increased, in order to ensure the same engine power output, the air inflow requirement of the engine is stable, the opening of the throttle valve is reduced, and the air pressure behind the throttle valve is suddenly reduced at the moment, so that the power output fluctuation is possibly caused; while causing engine pumping losses, the introduction of EGR increases engine combustion efficiency. In order to solve the problems, gradual transition is needed while the boost pressure is increased, the fluctuation of power output is avoided, and the oil consumption is not increased.
The boost pressure control method for improving the EGR rate of the embodiment of the invention, as shown in FIG. 1, comprises the following steps:
s1, determining an initial maximum boost pressure increment according to the target fresh air intake density of the engine and the actual rotating speed of the engine;
s2, setting a boost pressure increment change rate according to the allowable fluctuation range of the power fluctuation, wherein the boost pressure increment increase change rate and the boost pressure increment decrease change rate are included; obtaining the increment and the decrement of the boost pressure increment according to the change rate of the boost pressure increment, and performing transition processing on the initial maximum boost pressure increment by combining the control state of the boost pressure increment to obtain the final requested maximum boost pressure increment;
s3, determining a feed-forward part according to the target fresh air intake density of the engine and the actual rotating speed of the engine; acquiring an accumulation control part according to the supercharging pressure increment control state; obtaining a final actually requested boost pressure increase, which is limited between 0 and the final requested maximum boost pressure increase, by the feed-forward portion plus the accumulation control portion, based on the final requested maximum boost pressure increase; and finally, accumulating the final actually requested boost pressure increment to the target boost pressure of the boost control to obtain the final target boost pressure for the boost control.
The specific process is as follows:
first, according to the target fresh air intake density Rho of the engineAirDsrdWith enginesThe inter-speed nEngDetermining an initial non-transitional maximum boost pressure increase pBoostDeltaMaxRaw. As shown in table 1, on the bench, one point with the highest boost pressure (the pump power will increase to increase the fuel consumption, but the fuel efficiency will increase to decrease the fuel consumption) with the best fuel consumption is selected as the initial non-transitional maximum boost pressure increment p on the premise of ensuring the accurate EGR rate response by gradually increasing the boost pressure for each target fresh air intake density and the operating point of the actual engine speed (i.e. the difference between the actual EGR rate and the target EGR rate is within the index range, in this embodiment, the difference between the actual EGR rate and the target EGR rate divided by the target EGR rate is not allowed to exceed 1.5%)BoostDeltaMaxRaw。
TABLE 1 initial maximum boost pressure increase determination Table
Figure RE-GDA0002836817750000041
Second, for the initial non-transitional maximum boost pressure increase pBoostDeltaMaxRawAnd performing transition treatment to avoid the power output fluctuation exceeding a preset fluctuation range. And setting the incremental change rate of the supercharging pressure in the transition process according to the allowable fluctuation range of the dynamic fluctuation. The preset torque output fluctuation range of the embodiment exceeds +/-10 percent, namely, the torque control precision is not satisfied. The present example boost pressure increase change rate Δ pBoostDeltaIncAt 20kPa/s, the rate of change of incremental decrease in boost pressure Δ pBoostDeltaDecIs-40 kPa/s. Maximum boost pressure increase p for the final requestBoostDeltaMaxThe control of (2) sets 4 states:
1. when EGR is transitioned from inactive to active state, Δ p, as shown in FIG. 2BoostDeltaIncX Δ t and the front-to-rear pressure difference (p) of the throttle valvePreThrottle-pManifold) Maximum value max [ (Δ p)BoostDeltaInc×Δt),(pPreThrottle-pManifold)]Less than the initial non-transitional maximum boost pressure increase pBoostDeltaMaxRawWhen it is, max [ (Δ p)BoostDeltaInc×Δt),(pPreThrottle-pManifold)]<pBoostDeltaMaxRawWhen the final requested boost pressure increase pBoostDeltaMaxThe control state is in the Ramp Up state. Judging the control state of the last sampling period, and if the last sampling period is not the ramp up state, maintaining the current numerical value of the supercharging pressure increment; if the control state of the last sampling period is in the Ramp Up state, the boost pressure increment p is requestedBoostDeltaMaxOld(i.e. p)BoostDeltaMaxOld(n+1)＝pBoostDeltaMax(n)) plus the variation Δ pBoostDeltaIncX Δ t is determined as the current boost pressure increase pBoostDeltaMax. Time of day monitoring pBoostDeltaMaxOld+ΔpBoostDeltaIncX Δ t and the front-to-rear pressure difference (p) of the throttle valvePreThrottle-pManifold) Max [ (p)BoostDeltaMaxOld+ΔpBoostDeltaInc×Δt),(pPreThrottle-pManifold)]Less than the initial non-transitional maximum boost pressure increase pBoostDeltaMaxRawThe control state maintains the Ramp Up state. And ensuring that the pressure difference between the front and the rear of the throttle valve reaches the maximum or the increment of the requested supercharging pressure reaches the maximum so as to ensure that the EGR gas is normally guided into the cylinder. Maximum boost pressure increase p ultimately requested in Ramp Up stateBoostDeltaMaxTake max [ (p)BoostDeltaMaxOld+ΔpBoostDeltaInc×Δt),(pPreThrottle-pManifold)]。
2. Once max [ (p)BoostDeltaMaxOld+ΔpBoostDeltaInc×Δt),(pPreThrottle-pManifold)]Not less than the initial non-transitional maximum boost pressure increase pBoostDeltaMaxRawWhen the control state is updated to the Active state. Once the control state is Active, the control state does not enter the Ramp Up state from Active, but enters the Ramp Down state according to condition 3. And the final requested maximum boost pressure increase pBoostDeltaMaxMaintaining a maximum boost pressure increase pBoostDeltaMaxRaw。
3. When the EGR control state enters the inactive state, as shown in fig. 3, the control state enters the Ramp Down state from the Active state. Time of day monitoring pBoostDeltaMaxOld+ΔpBoostDeltaDecX Δ t and front-to-back pressure difference of throttle valve(pPreThrottle-pManifold) Min [ (p)BoostDeltaMaxOld+ΔpBoostDeltaDec×Δt),(pPreThrottle-pManifold)]When it is greater than 0, the control state is a Ramp Down state, and the finally requested boost pressure increase pBoostDeltaMaxIs equal to pBoostDeltaMaxOld+ΔpBoostDeltaDecx.DELTA.t until min [ (p)BoostDeltaMaxOld+ΔpBoostDeltaDec×Δt),(pPreThrottle-pManifold)]When the pressure is not more than 0, the control state is updated to the Off state, and the finally requested maximum boost pressure increment pBoostDeltaMaxEqual to 0. Once condition 1 is satisfied again, the state control of condition 1 is re-entered.
Up to this point, the maximum boost pressure increase p of its EGR requestBoostDeltaMaxAnd (4) determining.
Third, a boost pressure increase p of the final actual EGR request is madeBoostDeltaReqWhich is formed by a feedforward part pBoostDeltaReqFF+ accumulation control part pBoostDeltaReqIPartThus obtaining the product. Wherein the feed forward portion is an engine target fresh air charge density RhoAirDsrdAnd the actual speed n of the engineEngDetermined as shown in table 2.
TABLE 2 feed-forward part determination table
Figure RE-GDA0002836817750000061
When the boost-pressure-increase control state is the Off state, the accumulation control portion pBoostDeltaReqIPartIs 0; when the boost-pressure-increase control state is not the Off state, the accumulation control portion pBoostDeltaReqIPartThe obtaining method comprises the following steps:
1. as shown in Table 3, the fresh air intake density Rho is determined according to the engine targetAirDsrdAnd the actual speed n of the engineEngDetermining an optimal EGR control valve outlet and inlet exhaust gas target pressure ratio rEGRValvePresRatioDsrdIs compared with the actual pressure
Figure RE-GDA0002836817750000062
Making a difference to obtain rEGRValvePresRatioErrAnd finding the rate of change dr of the differenceEGRValvePresRatioErr. As shown in Table 4, according to the pressure ratio difference rEGRValvePresRatioErrSum-to-pressure ratio difference change rate drEGRValvePresRatioErrDetermining the cumulative rate of change p of the cumulative control partBoostDeltaReqIPartGain。
TABLE 3 control valve outlet and inlet exhaust target pressure ratio determination Table
Figure RE-GDA0002836817750000071
Table 4 cumulative change rate determination table of cumulative control part
Figure RE-GDA0002836817750000072
pBoostDeltaReqIPart(n+1)＝pBoostDeltaReqIPart(n)+
pBoostDeltaReqIPartGain(n+1)×Δt×(rEGRValvePresRatioErr(n+1)-kBoostWindUpGain×pBoostDeltaSatu(n+1))
In particular pBoostDeltaReqIPart(0)＝0，kBoostWindUpGainFor inverse integral saturation factor, 0.02, p is taken for this exampleBoostDeltaSatu(n +1) is the integrated saturated boost pressure during the (n +1) th sampling period. Final pBoostDeltaReqGet pBoostDeltaReqFF+pBoostDeltaReqIPartAnd is limited to 0 and a maximum boost pressure increase pBoostDeltaMaxIf p is the finalBoostDeltaReqIf the final result is exceeded, the final result is replaced with an end value close to the final result. p is a radical ofBoostDeltaSatu(n+1)＝pBoostDeltaReq(n)-[pBoostDeltaReqFF(n)+pBoostDeltaReqIPart(n)]To this end, the boost pressure increase p of the final EGR requestBoostDeltaReqControl is complete and finally p isBoostDeltaReqAdded to the target boost pressure of the boost controlAnd obtaining the final target supercharging pressure for supercharging control.
It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included within the scope of the present invention.

Claims (5)

1. A boost-pressure control method for improving an EGR rate, characterized by comprising the steps of:
s1, determining an initial maximum boost pressure increment according to the target fresh air intake density of the engine and the actual rotating speed of the engine;
s2, setting a boost pressure increment change rate according to the allowable fluctuation range of the power fluctuation, wherein the boost pressure increment increase change rate and the boost pressure increment decrease change rate are included; obtaining the increment and the decrement of the boost pressure increment according to the change rate of the boost pressure increment, and performing transition processing on the initial maximum boost pressure increment by combining the control state of the boost pressure increment to obtain the final requested maximum boost pressure increment;
s3, determining a feed-forward part according to the target fresh air intake density of the engine and the actual rotating speed of the engine; acquiring an accumulation control part according to the supercharging pressure increment control state; obtaining a final actually requested boost pressure increase, which is limited between 0 and the final requested maximum boost pressure increase, by the feed-forward portion plus the accumulation control portion, based on the final requested maximum boost pressure increase; and finally, accumulating the final actually requested boost pressure increment to the target boost pressure of the boost control to obtain the final target boost pressure for the boost control.
2. The boost-pressure control method for improving the EGR rate according to claim 1, wherein in step S2, in combination with the boost-pressure increase control state, the initial maximum boost-pressure increase is subjected to a transition process, and the finally requested boost-pressure increase is obtained by:
s21, when the EGR state is changed from the non-activated state to the activated state and the maximum value of the pressure difference between the supercharging pressure increment and the front and back of the throttle valve is smaller than the initial maximum supercharging pressure increment, the control state is set to be a Ramp Up state; judging the control state of the previous sampling period, and if the control state of the previous sampling period is not in a Ramp Up state, maintaining the boost pressure increment at the current value; if the control state of the previous sampling period is in a Ramp Up state, determining the previous boost pressure increment plus the boost pressure increment as the current boost pressure increment;
if the maximum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve is smaller than the initial maximum boost pressure increment, the Ramp Up state is maintained in the control state; taking the maximum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve as the final requested maximum boost pressure increment in the Ramp Up state;
s22, changing the control state from the Ramp Up state to the Active state until the maximum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve exceeds the initial maximum boost pressure increment;
s23, when the EGR state is changed from the Active state to the inactive state, the control state is changed from the Active state to the Ramp Down state; determining the last boost pressure increment plus the boost pressure increment decrease as the current boost pressure increment;
if the minimum value of the current boost pressure increment and the pressure difference between the front and the rear of the throttle valve is larger than 0, the Ramp Down state is maintained in the control state; taking the finally requested boost pressure increment in the Ramp Down state as the current boost pressure increment;
s24, until the minimum value between the current boost pressure increase and the pressure difference across the throttle valve is equal to or less than 0, the control state changes from the Ramp Down state to the Off state, and the finally requested maximum boost pressure increase is taken to 0.
3. The boost-pressure control method for improving the EGR rate according to claim 2, wherein the acquisition accumulation control portion in accordance with the boost-pressure increase control state in step S3 is embodied as:
s31, when the boost pressure increment control state is an Off state, the accumulative control part is 0;
s32, when the supercharging pressure increment control state is not the Off state, the accumulation control portion obtains the following method:
s321, determining an optimal EGR control valve outlet and inlet exhaust gas target pressure ratio according to the engine target fresh air intake density and the engine actual rotating speed, subtracting the optimal EGR control valve outlet and inlet exhaust gas target pressure ratio from the EGR control valve actual pressure ratio to obtain a pressure ratio difference, and calculating the change rate of the pressure ratio difference;
s322, determining the accumulated change rate of the accumulation control part according to the pressure ratio difference and the pressure ratio difference change rate;
and S323, obtaining an accumulation control part according to the accumulation change rate of the accumulation control part and a calculation formula of the accumulation control part.
4. The boost-pressure control method for improving the EGR rate according to claim 3, wherein the addition control portion calculates the formula as:
pBoostDeltaReqIPart(n+1)＝pBoostDeltaReqIPart(n)+pBoostDeltaReqIPartGain(n+1)×Δt×(rEGRValvePresRatioErr(n+1)-kBoostWindUpGain×pBoostDeltaSatu(n+1))
in the formula, pBoostDeltaReqIPartIndicating an accumulation control part, pBoostDeltaReqIPartGainIndicating the accumulated rate of change of the accumulation control section, at indicating a time interval, rEGRValvePresRatioErrIndicating the pressure ratio difference, kBoostWindUpGainRepresenting inverse integral saturation coefficient, pBoostDeltaSatuIndicating the integrated saturated boost pressure, and n, n +1 indicating the sampling period number.
5. The boost-pressure control method for improving the EGR rate according to claim 4, characterized in that the calculation formula of the integrated saturation boost pressure is:
pBoostDeltaSatu(n+1)＝pBoostDeltaReq(n)-[pBoostDeltaReqFF(n)+pBoostDeltaReqIPart(n)]
in the formula, pBoostDeltaReqIndicating the final requested boost pressure increase, pBoostDeltaReqFFDenotes the feedforward portion, pBoostDeltaReqIPartThe accumulation control section is shown.
CN202011245594.4A 2020-11-10 2020-11-10 Supercharging pressure control method for improving EGR rate Active CN112360635B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011245594.4A CN112360635B (en) 2020-11-10 2020-11-10 Supercharging pressure control method for improving EGR rate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011245594.4A CN112360635B (en) 2020-11-10 2020-11-10 Supercharging pressure control method for improving EGR rate

Publications (2)

Publication Number Publication Date
CN112360635A true CN112360635A (en) 2021-02-12
CN112360635B CN112360635B (en) 2021-08-03

Family

ID=74508456

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011245594.4A Active CN112360635B (en) 2020-11-10 2020-11-10 Supercharging pressure control method for improving EGR rate

Country Status (1)

Country Link
CN (1) CN112360635B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114962022A (en) * 2022-06-29 2022-08-30 东风汽车集团股份有限公司 Control method for improving intake pressure fluctuation
CN115199422A (en) * 2022-06-29 2022-10-18 东风汽车集团股份有限公司 Control method of low-pressure EGR system mixing valve

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5313798A (en) * 1991-08-02 1994-05-24 Toyota Jidosha Kabushiki Kaisha Charging control apparatus for an internal combustion engine with a dual turbocharger system
JP2006207409A (en) * 2005-01-26 2006-08-10 Honda Motor Co Ltd Control device for internal combustion engine
CN101446241A (en) * 2007-11-30 2009-06-03 株式会社日立制作所 Engine control system and control method thereof
CN105351078A (en) * 2014-08-18 2016-02-24 比亚迪股份有限公司 Control method and control device for turbocharging air circulation valve of engine
CN108571389A (en) * 2017-03-13 2018-09-25 本田技研工业株式会社 The control device of internal combustion engine
CN111287856A (en) * 2020-02-22 2020-06-16 东风汽车集团有限公司 Method for determining target intake pressure of exhaust gas turbocharged engine, control method, and storage medium

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5313798A (en) * 1991-08-02 1994-05-24 Toyota Jidosha Kabushiki Kaisha Charging control apparatus for an internal combustion engine with a dual turbocharger system
JP2006207409A (en) * 2005-01-26 2006-08-10 Honda Motor Co Ltd Control device for internal combustion engine
CN101446241A (en) * 2007-11-30 2009-06-03 株式会社日立制作所 Engine control system and control method thereof
CN105351078A (en) * 2014-08-18 2016-02-24 比亚迪股份有限公司 Control method and control device for turbocharging air circulation valve of engine
CN108571389A (en) * 2017-03-13 2018-09-25 本田技研工业株式会社 The control device of internal combustion engine
CN111287856A (en) * 2020-02-22 2020-06-16 东风汽车集团有限公司 Method for determining target intake pressure of exhaust gas turbocharged engine, control method, and storage medium

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114962022A (en) * 2022-06-29 2022-08-30 东风汽车集团股份有限公司 Control method for improving intake pressure fluctuation
CN115199422A (en) * 2022-06-29 2022-10-18 东风汽车集团股份有限公司 Control method of low-pressure EGR system mixing valve
CN114962022B (en) * 2022-06-29 2023-05-05 东风汽车集团股份有限公司 Control method for improving intake pressure fluctuation
CN115199422B (en) * 2022-06-29 2023-08-25 东风汽车集团股份有限公司 Control method of mixing valve of low-pressure EGR system

Also Published As

Publication number Publication date
CN112360635B (en) 2021-08-03

Similar Documents

Publication Publication Date Title
US8096123B2 (en) System and method for mode transition for a two-stage series sequential turbocharger
CN108087108B (en) Control system and method for exhaust gas bypass type supercharger of natural gas engine
CN112360635B (en) Supercharging pressure control method for improving EGR rate
CN112523878B (en) EGR valve closed-loop control method based on EGR rate
CN105673543A (en) Control method for preventing turbocharger surges
CN107762653B (en) Temperature control system of diesel oxidation catalyst
CN112177783A (en) Low-pressure exhaust gas recirculation system suitable for biodiesel engine and control method
CN113074056B (en) Full-working-condition diesel micro-injection ignition control method
CN111206998A (en) Method for controlling transient process of engine based on supercharging pressure deviation
Cheong et al. Effect of Variable Geometry Turbocharger on HSDI Diesel Engine
CN116838505A (en) EGR (exhaust gas recirculation) system of hybrid supercharged engine and control method
CN116857076A (en) Exhaust gas recirculation control method and system
CN110748442A (en) Throttle-free air inlet system of spark ignition engine and power control method
CN111219263B (en) Method for determining supercharging feedforward control coefficient of exhaust gas turbine engine and storage medium
CN202100325U (en) Auxiliary supercharging system of internal combustion engine
CN111608813B (en) Engine exhaust temperature management method and device and engine
CN104791146A (en) Gas inlet and exhausting system of internal combustion engine
CN114738109B (en) Matching method for key parameters of two-stage turbocharged internal combustion engine
CN115199422B (en) Control method of mixing valve of low-pressure EGR system
JP2005299570A (en) Premixed combustion control system for compression ignition internal combustion engine
CN114526153B (en) Electric auxiliary supercharging system for marine diesel engine and control method
CN112459910B (en) Method and system for calculating target EGR rate
CN208564743U (en) A kind of internal combustion engine two-stage turbine load device for controlling dynamically
CN117418946B (en) EGR system, control method thereof and engine
CN114135392B (en) Engine thermal management system and method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant