CN111140389A - Oxygen cleaning method for gasoline engine catalyst - Google Patents

Oxygen cleaning method for gasoline engine catalyst Download PDF

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CN111140389A
CN111140389A CN201911358264.3A CN201911358264A CN111140389A CN 111140389 A CN111140389 A CN 111140389A CN 201911358264 A CN201911358264 A CN 201911358264A CN 111140389 A CN111140389 A CN 111140389A
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catalyst
oxygen
condition
cleaning
excess air
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CN111140389B (en
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欣白宇
高天宇
王强
张波
刘笑飞
苗志慧
杜大瑞
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FAW Group Corp
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FAW Group Corp
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    • 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
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • F01N11/007—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
    • 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
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1473—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method
    • F02D41/1475—Regulating the air fuel ratio at a value other than stoichiometry
    • 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
    • F02D41/30—Controlling fuel injection
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/10—Parameters related to the engine output, e.g. engine torque or engine speed
    • F02D2200/101—Engine speed
    • 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

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The invention relates to a gasoline engine catalyst oxygen cleaning method. The oxygen cleaning method comprises the following steps: (1) judging whether the basic oxygen-cleaning condition of the catalyst is met; (2) when the basic condition in the step (1) is met, judging whether a catalyst oxygen storage calculation starting condition is met; (3) when the starting condition in the step (2) is met, calculating the oxygen storage amount of the catalyst; (4) and when the catalyst oxygen cleaning condition is met, calculating the catalyst oxygen cleaning amount and performing oxygen cleaning operation. The oxygen cleaning method is based on a physical model of oxygen storage and cleaning processes of the catalyst, and can accurately and efficiently control the fuel injection quantity to clean redundant oxygen in the catalyst through mathematical derivation. Moreover, the control parameters of the oxygen cleaning method mainly depend on the characteristics of an engine system, so that the time required by calibration can be saved, and the application scene is wider.

Description

Oxygen cleaning method for gasoline engine catalyst
Technical Field
The invention relates to the field of electronic control of gasoline engines, in particular to an oxygen removal method for a gasoline engine catalyst.
Background
When a driver does not need power during running of the motor vehicle, in order to save unnecessary fuel consumption, the ECU sends a fuel cut-off command, and the torque output of the engine is stopped by stopping fuel injection, for example, fuel cut-off is often triggered by fuel collection operation after the vehicle runs in an accelerating mode. Because the fuel cut of the vehicle does not perform the fuel injection action, the fresh air can be directly discharged to various parts of an exhaust system through the cylinder and the exhaust valve, and at the moment, the catalyst is continuously flushed by the fresh air which is relatively lean relative to the combustible mixture. When the power output of the engine is recovered, the combusted mixed exhaust gas can normally enter the catalyst, and the catalyst is used for converting the emission. However, since the catalyst is a fine honeycomb carrier, the over-diluted fresh air remaining in the catalyst carrier cannot be recovered to a good exhaust gas catalytic reaction state in a short time, so that a large amount of redundant oxygen is left in the catalyst, and the conversion efficiency of the catalyst is greatly reduced, so that the nitrogen oxide discharged by a vehicle under the fuel cut recovery working condition is rapidly increased, and the emission is deteriorated.
Aiming at the working condition of fuel cut recovery or continuous over-lean air-fuel ratio, the ECU is required to accurately identify the starting and ending states of the working condition and quickly remove redundant oxygen in the catalytic converter so as to ensure good conversion efficiency of the catalytic converter.
Currently, the prior art discloses some solutions. For example CN104704219A discloses a device for limiting oxygen content in the exhaust gas of an internal combustion engine of a motor vehicle, comprising a module for determining the maximum admissible oxygen volume concentration at the inlet of an exhaust pipe catalyst, a module for determining the oxygen volume concentration in the gases from the combustion of the engine, a module for determining the maximum admissible air purge mass flow based on the maximum admissible oxygen volume concentration in the exhaust gas and the oxygen volume concentration in the gases from the combustion, and a control module for implementing the opening and closing of the engine intake and exhaust valves based on the maximum admissible air purge set point thus determined. Although the device can prevent the catalyst from being aged due to the overhigh oxygen proportion in the high-temperature exhaust gas, the device has limited application range, and especially does not consider the complicated working condition that the oxygen content in the catalyst is overhigh when the oil supply is restored again after the oil cut of the engine.
CN106150763A discloses an electronic controller for purifying CO and HC in automobile exhaust, which mainly adopts the principle that an electronic control unit monitors a rotation speed signal and a throttle position signal of an engine in real time, and adjusts the air replenishment rate in real time by setting an air replenishment pipeline and realizing a control working mode by using an air pump and a high-frequency electromagnetic valve, thereby reducing the emission of CO and HC in the exhaust. Although the controller has simple structure and low installation cost, and can solve the problem of overhigh emission of CO and HC caused by aging of the three-way catalyst or use of inferior fuel oil, the controller does not solve the problem of overhigh emission of NOx caused by overhigh oxygen content of the catalyst.
CN109519264A discloses a gasoline engine three-way catalyst diagnosis rapid diagnosis method and system, the rapid diagnosis system comprises a receiving module, an oil injection control module, an oil injection module, a downstream oxygen sensor module and a diagnosis module, the more concentrated or less concentrated stage of the gasoline engine can be adjusted, then the working fault is rapidly diagnosed according to the monitoring of the downstream oxygen sensor, and the working fault is solved by controlling the oil injection quantity of the gasoline engine. Although the rapid diagnosis method can be used for diagnosing the three-way catalyst based on the existing device, the time for diagnosing whether the three-way catalyst of the gasoline engine is aged is shortened as much as possible, and pollutants are effectively reduced, the oxygen content of the catalyst is not accurately judged, and redundant oxygen is eliminated.
CN205876519U discloses a gasoline engine transient air-fuel ratio optimization control device, which comprises an engine, an oil film compensation system and a feedback control system, wherein the input end of the engine is connected with the oil film compensation system, and the output end of the engine is connected with the feedback control system; the oil film compensation system comprises an identifier, an oil film model calculator, a control device and an oil sprayer; the feedback control system comprises a predictor, a control device and an oil injector. The transient air-fuel ratio controller parameter optimization model based on the chaos optimization algorithm has better engine parameter optimization capability, further effectively improves the control precision of the transient air-fuel ratio, and simultaneously improves the power performance, the economic performance and the emission performance of the engine. Although the invention can solve the problem of difficult air-fuel ratio control caused by the dynamic effect of the oil film under the transient working condition of the engine, compared with an air inlet channel injection gasoline engine, the influence of the dynamic effect of the oil film of the direct injection gasoline engine on the air-fuel ratio is smaller, so the invention can not improve the emission deterioration of the direct injection gasoline engine for recovering the oil supply working condition, and has extremely limited application range.
Although the above solutions in the prior art can properly solve the problem of low conversion efficiency caused by excessive oxygen in the catalyst, the methods have limited application range and low control accuracy. Therefore, there is a need to develop an effective method for purging oxygen of gasoline engine catalyst.
Disclosure of Invention
In view of the problems in the prior art, the invention provides an oxygen removal method for a gasoline engine catalyst. The oxygen cleaning method comprises four main steps of judgment of basic oxygen cleaning conditions of the catalyst, judgment of starting oxygen storage calculation conditions of the catalyst, calculation of oxygen storage amount of the catalyst, calculation of oxygen cleaning amount of the catalyst and oxygen cleaning operation. The oxygen cleaning method is based on a physical model of oxygen storage and cleaning processes of the catalyst, and can accurately and efficiently control the fuel injection quantity to clean redundant oxygen in the catalyst through mathematical derivation. Moreover, the control parameters of the oxygen cleaning method mainly depend on the characteristics of an engine system, so that the time required by calibration can be saved, and the application scene is wider.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention aims to provide an oxygen cleaning method for a gasoline engine catalyst, which comprises the following steps:
(1) judging whether the basic oxygen-cleaning condition of the catalyst is met;
(2) when the basic condition in the step (1) is met, judging whether a catalyst oxygen storage calculation starting condition is met;
(3) when the starting condition in the step (2) is met, calculating the oxygen storage amount of the catalyst;
(4) when the catalyst oxygen cleaning condition is met, calculating the catalyst oxygen cleaning amount and performing oxygen cleaning operation;
when the step (1) or the step (2) does not meet the corresponding condition, directly ending;
and (5) when the catalyst oxygen cleaning condition is not met in the step (4), continuously judging the condition.
The oxygen cleaning method is suitable for gasoline engines and motor vehicles provided with components such as a catalyst front oxygen sensor, a three-way catalyst, a catalyst rear oxygen sensor, an ECU controller and the like, is particularly suitable for the working conditions that the gasoline engine is cut off and oil supply and the air-fuel ratio is continuously leaner, can accurately and efficiently control the oil injection quantity to clean redundant oxygen in the catalyst, and ensures that the catalyst can rapidly recover the state of high-efficiency conversion of emissions.
The basic concept of the oxygen removal method is as follows: the basic oxygen cleaning condition of the catalyst is judged by detecting the rotating speed of an engine and the monitoring state of an ECU (electronic control unit) on the catalyst, if the accurate oxygen storage amount of the catalyst is obtained through calculation, the excessive oxygen is found to be contained in the catalyst and the oxygen cleaning operation of the catalyst is needed, the enrichment state of the engine and the time of the oxygen cleaning operation are efficiently and accurately judged through the exhaust flow of the catalyst, the acquisition value of an oxygen sensor before the catalyst and the acquisition value of an oxygen sensor after the catalyst, finally, the oxygen cleaning function of the catalyst is realized by setting the excess air coefficient corresponding to the target air-fuel ratio and adding the enriched mixed gas based on the air-fuel ratio closed-loop control function, and the emission performance of the engine is improved.
Based on the basic concept, the invention has the following preferable technical scheme:
as a preferable technical solution of the present invention, the meeting of the catalyst oxygen purging basic condition in step (1) means that the engine speed is less than the oxygen purging activation speed and the monitoring state of the catalyst by the engine control unit ECU is not in the on-board diagnosis OBD.
The oxygen-cleaning activation rotating speed and the design and the performance of the engine are related, the smoothness of air flow of the engine flowing through the catalytic converter at different rotating speeds is determined, and the oxygen-cleaning activation rotating speed can be adjusted according to the actual conditions of the engine and the whole vehicle.
As a preferable technical solution of the present invention, satisfying the catalyst oxygen storage calculation start condition in step (2) means that the excess air coefficient monitored by the pre-catalyst oxygen sensor is higher than the oxygen storage calculation start excess air coefficient λ1And the duration is greater than the calculated limit duration of oxygen storage T.
The excess air ratio in the present invention refers to the ratio of the amount of air actually supplied to the fuel for combustion to the stoichiometric air amount, and also refers to the ratio of the actual air-fuel ratio to the stoichiometric air-fuel ratio, and generally, the stoichiometric air-fuel ratio of gasoline is 14.7.
The oxygen storage calculation of the present invention begins the excess air factor lambda1The oxygen content of the air flow flowing through the catalytic converter to influence the oxygen balance of the catalytic converter is determined, and the oxygen content can be adjusted according to the actual conditions of the engine and the whole vehicle.
The oxygen storage calculation limit duration T is related to the design and performance of the engine, is determined by the exhaust delay of the engine, and can be adjusted according to the actual conditions of the engine and the whole vehicle.
As a preferable technical scheme of the invention, the step (3) adopts an integral calculation mode to calculate the oxygen storage amount of the catalyst.
Preferably, the integral calculation is formulated as:
Figure BDA0002336542100000051
wherein M isOxyThe oxygen storage capacity of the catalyst is g;
λLeancalculating an excess air factor value monitored by a pre-catalyst oxygen sensor at a start condition for catalyst oxygen storage;
mairthe unit is the catalyst inlet flow in kg/h.
The step (3) of the invention corresponds to the air inlet flow m of the catalyst in the integral calculation formulaairIn a state of real-time change, and its change in the period from the start to the end of the catalyst oxygen storage amount integral calculation is the subject of the catalyst oxygen storage amount integral calculation.
As a preferable technical scheme of the invention, when the end condition of calculating the oxygen storage amount of the catalyst in the step (3) is met, the calculation of the oxygen cleaning amount of the catalyst in the step (3) is terminated, the judgment of the oxygen cleaning condition of the catalyst in the step (4) is started, otherwise, the calculation of the oxygen cleaning amount of the catalyst is continued;
preferably, any one of the following conditions is regarded as the end condition of calculating the oxygen storage amount of the catalyst in step (3):
case a: the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the calculated excess air coefficient lambda2；
Case b: the oxygen storage amount of the catalyst reaches a saturated state.
Preferably, case b again includes b1And b2Two cases are:
case b1: the oxygen storage amount of the catalyst obtained by calculation is larger than the limit oxygen storage amount M of the catalystOxyStorage；
Case b2: the excess air coefficient monitored by the oxygen sensor behind the catalyst is higher than the catalyst oxygen storage saturation excess air coefficient lambda3。
Preferably, the condition b is judged to be satisfied to mean the condition b1Or b2The condition b is judged not to be satisfied and the condition b is1And b2Are not satisfied.
The oxygen storage calculation of the invention ends the excess air coefficient lambda2The design and the performance of the engine are related, the size, the structure and the content of noble metal of the catalyst are determined, and the adjustment can be carried out according to the actual engine and the whole vehicle condition.
The limit oxygen storage amount M of the catalytic converterOxyStorageThe design and the performance of the engine are related, the size, the structure and the content of noble metal of the catalyst are determined, and the adjustment can be carried out according to the actual engine and the whole vehicle condition.
The oxygen storage amount of the catalyst is saturatedAir volume coefficient lambda3The design and the performance of the engine are related, the performance of the catalyst is determined, and the adjustment can be carried out according to the actual engine and the whole vehicle condition.
As a preferable technical scheme of the invention, the step (4) of meeting the catalyst oxygen-cleaning condition means that the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the initial excess air coefficient lambda of cleaning oxygen4。
Preferably, the oxygen-scavenging start air excess factor λ4The excess air coefficient lambda is calculated to end the oxygen storage2。
The initial excess air coefficient lambda of the oxygen cleaning4The design and the performance of the engine are related, the size, the structure and the content of noble metal of the catalyst are determined, and the adjustment can be carried out according to the actual engine and the whole vehicle condition. When lambda is4≤λ2When, in particular λ4＜λ2Namely, the excess air coefficient monitored by the oxygen sensor in front of the catalyst is lower than the excess air coefficient when the oxygen storage calculation is finished, so that the over-dilute oxygen balance state of the catalyst can be fully broken, and the oxygen cleaning effect is ensured.
As a preferable technical scheme of the invention, the step (4) adopts an integral calculation mode to calculate the catalyst oxygen cleaning amount.
Preferably, the integral calculation is formulated as:
Figure BDA0002336542100000071
wherein M isOxyPurgeThe unit is g and is the oxygen cleaning amount of the catalyst;
λDesan excess air coefficient value corresponding to a target air-fuel ratio for the oxygen scavenging process;
mairthe unit is the catalyst inlet flow in kg/h.
The step (4) of the invention corresponds to the air inlet flow m of the catalyst in the integral calculation formulaairIn a state of real-time change, and its change in the period from the start to the end of the catalyst oxygen storage amount integral calculation is the subject of the catalyst oxygen storage amount integral calculation.
In a preferred embodiment of the present invention, the end condition of step (4) is considered to be satisfied when any one of the following conditions is satisfied:
a case a': if the catalyst oxygen storage calculation starting condition in the step (2) is met, re-executing the catalyst oxygen storage calculation in the step (3), otherwise, continuing to judge the condition b 'and the condition c';
case b': the catalyst oxygen cleaning amount is larger than the minimum catalyst oxygen cleaning amount MPurgeLimitAnd the excess air ratio monitored by the post-catalyst oxygen sensor is lower than the end-of-purge-oxygen excess air ratio lambda5；
In the case c': and (4) the oxygen storage amount of the catalyst obtained in the step (3) is larger than k times of the oxygen cleaning amount of the catalyst.
Preferably, the multiple k in case c' is 1 to 1.5, such as 1, 1.05, 1.1, 1.15, 1.2, 1.24, 1.3, 1.35, 1.4, 1.45 or 1.5, etc., but is not limited to the recited values, and other values not recited in the numerical range are equally applicable.
Preferably, when the condition b 'or the condition c' is satisfied, not only the end condition of the step (4) but also a mark of the end of the whole oxygen cleaning method is considered; when the condition b 'and the condition c' are not satisfied, continuing to calculate the catalyst oxygen cleaning amount and performing the oxygen cleaning operation in the step (4).
Minimum catalyst oxygen removal M of the inventionPurgeLimitRefers to the minimum amount of oxygen that needs to be purged once the purging operation is initiated, ensuring that the purging operation, once initiated, has the beneficial effect of purging a portion of the catalyst of oxygen. The minimum catalyst oxygen removal amount MPurgeLimitThe engine design and performance are related, and the engine exhaust pipeline volume and the exhaust delay are determined, so that the engine exhaust pipeline volume and the exhaust delay can be adjusted according to the actual engine and the whole vehicle condition.
The excess air coefficient lambda of the invention is finished by oxygen cleaning5The design and the performance of the engine are related, the size, the structure and the content of noble metal of the catalyst are determined, and the adjustment can be carried out according to the actual engine and the whole vehicle condition.
As a preferable technical scheme of the invention, the oxygen cleaning operation setting target air-fuel ratio in the step (4) corresponds toExcess air ratio λ ofaimAnd adding the rich mixed gas.
Preferably, the rich mixture is rich-compensated via an air-fuel ratio closed-loop control function.
As a preferable technical scheme of the invention, the oxygen cleaning method comprises the following steps:
(1) judging whether the basic oxygen-cleaning condition of the catalyst is met;
wherein, the condition that the basic oxygen cleaning condition of the catalyst is met means that the engine speed is less than the oxygen cleaning activation speed and the monitoring state of the on-board diagnosis OBD of the catalyst is not monitored by an engine control unit ECU;
(2) when the basic condition in the step (1) is met, judging whether a catalyst oxygen storage calculation starting condition is met;
wherein satisfying the catalyst oxygen storage calculation start condition means that the excess air coefficient monitored by the pre-catalyst oxygen sensor is higher than the oxygen storage calculation start excess air coefficient λ1And the duration is greater than the calculated limit duration T of oxygen storage;
(3) when the starting condition of the step (2) is met, adopting an integral calculation mode according to a formula
Figure BDA0002336542100000081
Calculating oxygen storage amount of the catalyst, terminating the calculation of the oxygen cleaning amount of the catalyst when the ending condition of calculating the oxygen storage amount of the catalyst is met, starting to judge the oxygen cleaning condition of the catalyst in the step (4), and otherwise, continuing to calculate the oxygen cleaning amount of the catalyst;
wherein, any one of the following conditions is regarded as the end condition for calculating the oxygen storage amount of the catalyst:
case a: the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the calculated excess air coefficient lambda2；
Case b: the oxygen storage amount of the catalyst reaches a saturated state;
(4) when the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the initial excess air coefficient lambda of the clean oxygen4If the oxygen removal condition of the catalyst is met, integral calculation is adoptedAccording to the formula
Figure BDA0002336542100000091
Calculating the oxygen cleaning amount of the catalyst, and simultaneously setting an excess air coefficient lambda corresponding to a target air-fuel ratioaimThe enrichment compensation of the mixed gas is realized through the closed-loop control function of the air-fuel ratio;
wherein, when any one of the following conditions is satisfied, the condition is regarded as the end condition of the step (4):
a case a': if the catalyst oxygen storage calculation starting condition in the step (2) is met, re-executing the catalyst oxygen storage calculation in the step (3), otherwise, continuing to judge the condition b 'and the condition c';
case b': the catalyst clean oxygen amount is larger than the minimum catalyst clean oxygen amount standard catalyst clean oxygen amount MPurgeLimitAnd the excess air ratio monitored by the post-catalyst oxygen sensor is lower than the end-of-purge-oxygen excess air ratio lambda5；
In the case c': the oxygen storage amount of the catalyst obtained in the step (3) is larger than k times of the oxygen cleaning amount of the catalyst;
when the condition b 'or the condition c' is met, the condition is not only considered as the ending condition of the step (4), but also as a mark for ending the whole oxygen cleaning method; when the condition b 'and the condition c' are not satisfied, continuing to calculate the catalyst oxygen cleaning amount and performing the oxygen cleaning operation in the step (4).
Compared with the prior art, the invention has at least the following beneficial effects:
(1) the method for cleaning the oxygen of the gasoline engine catalyst can accurately and efficiently control the fuel injection quantity to clean redundant oxygen in the catalyst through mathematical derivation based on the physical model of the oxygen storage and cleaning processes of the catalyst;
(2) the control parameters of the oxygen removal method for the gasoline engine catalyst mainly depend on the characteristics of an engine system, so that the time required by calibration can be saved, and the application scene is wider;
(3) the method for clearing oxygen of the gasoline engine catalyst is suitable for gasoline engines and motor vehicles which are provided with components such as a catalyst front oxygen sensor, a three-way catalyst, a catalyst rear oxygen sensor, an ECU controller and the like, and is particularly suitable for the working conditions that the gasoline engine is cut off and oil supply is recovered and the air-fuel ratio is continuously leaner.
Drawings
FIG. 1 is a control block diagram of the oxygen purging operation of the catalyst of the gasoline engine according to the present invention;
FIG. 2a is a software flow chart of the oxygen cleaning method of the catalyst of the gasoline engine;
FIG. 2b is a diagram illustrating an example of a main routine for determining a calculation condition for starting oxygen storage amount of a catalyst in the gasoline engine catalyst oxygen removal method according to the present invention;
FIG. 2c is a schematic diagram of an exemplary main routine of the oxygen purging method for a catalyst of a gasoline engine according to the present invention for calculating oxygen storage amount of the catalyst and determining the oxygen purging start condition;
FIG. 2d is a diagram illustrating a main routine of the oxygen purging method for a gasoline engine catalyst according to the present invention for calculating the amount of purged oxygen and performing the oxygen purging operation by setting the value of the excess air ratio corresponding to the target air-fuel ratio;
FIG. 3 is a graph showing the effect of calculation of oxygen storage amount of the catalyst in example 1 of the present invention;
FIG. 4 is a diagram showing the effect of the catalyst oxygen purging control according to embodiment 1 of the present invention;
FIG. 5 is a graph showing the effect of calculation of oxygen storage amount of the catalyst in example 2 of the present invention;
FIG. 6 is a diagram showing the effect of the catalyst oxygen purging control according to embodiment 2 of the present invention.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
FIG. 1 shows a control block diagram of the oxygen purging operation of the gasoline engine catalyst, which mainly embodies the synergistic effect of the oxygen purging operation and the air-fuel ratio closed-loop control function, and specifically comprises the following steps: the catalyst cleaning control module needs to monitor the front excess air coefficient and the rear excess air coefficient of the catalyst in real time so as to judge whether the starting condition and the ending condition of the catalyst cleaning control are met, calculate the cleaning oxygen amount of the catalyst according to the air intake flow and the excess air coefficient corresponding to the expected air-fuel ratio, and output the excess air coefficient corresponding to the target air-fuel ratio during cleaning oxygen; the state selection switch is mainly used for selecting an excess air coefficient corresponding to a target air-fuel ratio during oxygen cleaning and an excess air coefficient corresponding to a target air-fuel ratio during non-oxygen cleaning according to a judgment result of the oxygen cleaning state of the catalyst, and one of the excess air coefficient and the excess air coefficient is used as an excess air coefficient corresponding to the target air-fuel ratio and is input into the air-fuel ratio closed-loop control module; the air-fuel ratio closed-loop control module finally outputs the air-fuel ratio closed-loop output control quantity according to two parameters, namely the excess air coefficient corresponding to the target air-fuel ratio determined by the state selection switch and the excess air coefficient in front of the catalytic converter monitored in real time, so that the synergistic effect of the oxygen cleaning operation and the air-fuel ratio closed-loop control function is realized, and the advantages that the oxygen cleaning method mainly depends on the characteristics of an engine system, the time required by calibration can be saved, and the applicable scene is wider are embodied.
FIG. 2a shows a software flow chart of the oxygen removal method of the gasoline engine catalyst, which specifically comprises the following steps: the ECU monitors the rotating speed of the engine and the monitoring state of the on-board diagnostic OBD on the catalyst in real time, when the rotating speed of the engine is judged to be less than the oxygen-cleaning activation rotating speed and the catalyst is not in the monitoring state of the on-board diagnostic OBD by the engine control unit ECU, the basic oxygen-cleaning condition of the catalyst is considered to be met, otherwise, the oxygen-cleaning software program is directly ended; on the basis of meeting the basic condition of catalyst oxygen cleaning, the excess air coefficient is monitored in real time by a pre-catalyst oxygen sensor, and when the pre-catalyst excess air coefficient value is higher than the value of the oxygen storage calculation start excess air coefficient lambda1And the duration is longer than the calculated limit duration T of oxygen storage, namely the calculated oxygen storage quantity M of the catalyst is considered to be satisfiedOxyIf not, directly ending the oxygen removal software program; when the calculation M is satisfiedOxyWhen starting the conditions of (1), start to perform the process on MOxyIntegral calculation is performed until the value of the pre-catalyst excess air coefficient is lower than the value of the oxygen storage calculation end excess air coefficient lambda2Or any condition that the oxygen storage amount of the catalyst reaches a saturation state is monitored to occur, and then M is finishedOxyIf both of the foregoing are negative, then M is returnedOxyIntegral calculation of (2); when the pair M is finishedOxyWhen calculating the integral of (A), it is necessary to judge whether the catalyst oxygen purging condition is satisfied, that is, the front excess air coefficient of the catalyst is lower than the initial excess air coefficient lambda of purging oxygen4Otherwise, continuously judging the oxygen cleaning condition of the catalyst; on the basis of meeting the condition of catalyst oxygen cleaning, the oxygen cleaning amount M of the catalyst is startedOxyPurgeIntegral calculation is carried out, and simultaneously, the excess air coefficient lambda corresponding to the target air-fuel ratio is setaimAdding the enriched mixed gas, and judging whether the calculation M is met or not in real timeOxyIf the conditions are satisfied, returning to the calculation of the oxygen storage amount of the catalyst immediately, otherwise, continuing to judge that M is the following two conditionsOxyPurgeGreater than the minimum catalyst oxygen removal MPurgeLimitAnd the post-catalyst excess air coefficient value is lower than the oxygen-removal end excess air coefficient lambda5Or MOxyPurgeM greater than k timesOxy(ii) a If the judgment of the two conditions is negative, returning to the oxygen removal operation of the catalyst for continuous execution; if the judgment in either case is positive, the judgment is not only taken as the end condition of the step (4) but also as a mark for ending the whole oxygen cleaning method.
Example 1
The embodiment provides an oxygen cleaning method for a gasoline engine catalyst, which aims at recovering the oil supply working condition after the oil supply of a certain four-cylinder gasoline engine is cut off, and the whole strategy implementation process takes 20 milliseconds as the calculation step length;
(1) judging whether the basic conditions of the oxygen removal of the catalyst are met:
in the running process of the engine, monitoring that the engine speed is 1400rpm and is lower than the oxygen cleaning activation speed 4000rpm and the ECU monitors that the catalyst is not in an OBD state, so that basic conditions of the catalyst for cleaning oxygen are met;
(2) when the basic condition described in the step (1) is satisfied, it is judged whether or not a catalyst oxygen storage calculation start condition is satisfied, in which the oxygen storage calculation start excess air ratio λ11.25, the oxygen storage calculation limit duration T is 0.5 s;
when the fuel cut-off working condition occurs in the running process of the vehicle, such as the sudden accelerator pedal, and the fuel cut-off working condition lasts for 4.8s, the fuel supply is recovered, and the situation that the fuel is supplied before the catalyst is monitoredThe value of the excess air coefficient rapidly increases to 16 and lasts for 4.8s, so that the excess air coefficient monitored by the pre-catalyst oxygen sensor is higher than the value of the excess air coefficient lambda at the beginning of oxygen storage calculation1And the duration is greater than the oxygen storage calculation starting condition of the catalyst of the oxygen storage calculation limit duration T, the ECU starts to calculate the oxygen storage amount of the catalyst;
(3) when the starting condition of the step (2) is met, adopting an integral calculation mode according to a formula
Figure BDA0002336542100000131
Calculating the oxygen storage amount of the catalyst, wherein the oxygen storage calculation of the condition a ends the excess air coefficient lambda2＝1；
Value of excess air coefficient lambda monitored by pre-catalyst oxygen sensor at the start of catalyst oxygen storage calculationLeanIs 16; the condition for finishing the oxygen storage calculation of the catalyst is that after the fuel cut-off working condition lasts for 4.8s and the fuel supply is recovered, the excess air coefficient monitored by an oxygen sensor in front of the catalyst is 0.99 which is lower than the excess air coefficient lambda after the oxygen storage calculation is finished2(ii) a As shown in FIG. 3, catalyst intake flow rate mairContinuously changing in 4.8s of continuous oil-cut working condition, gradually decreasing from 9.1kg/h to 7.6kg/h, and finally calculating the integral to obtain the oxygen storage quantity M of the catalystOxy2.1 g;
(4) when the oxygen-removing condition of the catalyst is met, adopting an integral calculation mode according to a formula
Figure BDA0002336542100000132
Calculating the amount of catalyst oxygen and performing oxygen-cleaning operation, wherein the oxygen-cleaning begins to have excess air coefficient lambda40.995, an excess air coefficient value λ corresponding to a target air-fuel ratio for the oxygen scavenging processDesCase b' minimum catalyst oxygen purge M ═ 0.93PurgeLimit0.2g, case b' said purge end air excess factor λ5＝0.99；
When the engine finishes fuel cut and resumes fuel supply, the end condition of the oxygen storage amount calculation of the catalyst in the step (3) meets the catalyst oxygen cleaning condition in the step (4), namely the excess air coefficient monitored by the oxygen sensor in front of the catalyst is lower than 0.99Initial excess air factor lambda of oxygen scavenging4The ECU begins to calculate the oxygen content M of the catalystOxyPurgeAnd performing a catalyst oxygen purging operation; the condition of ending the step (4) is that the calculated catalyst clear oxygen amount has exceeded the minimum catalyst clear oxygen amount MPurgeLimitAnd the excess air ratio monitored by the post-catalyst oxygen sensor is 0.98 below the end-of-clean-oxygen excess air ratio lambda5The whole oxygen cleaning process lasts for 11.5s from beginning to end; as shown in FIG. 3, catalyst intake flow rate mairContinuously changing within 11.5s of the continuous oxygen-removing process, wherein the change range is between 6.2kg/h and 9.1kg/h, and finally integrating the catalyst oxygen-removing amount M obtained by calculationOxyPurgeIt was 1.8 g.
It can be seen from fig. 4 corresponding to this embodiment that, in the oxygen purging process, the value of the actual excess air coefficient before the catalyst is reduced from 1 to 0.93, and then the actual excess air coefficient is restored to the normal value 1 again, so that the residual oxygen in the catalyst is purged accurately and efficiently.
Example 2
The embodiment provides an oxygen cleaning method for a gasoline engine catalyst, which aims at recovering the oil supply working condition after the oil supply of a certain four-cylinder gasoline engine is cut off, and the whole strategy implementation process takes 20 milliseconds as the calculation step length;
(1) judging whether the basic conditions of the oxygen removal of the catalyst are met:
in the running process of the engine, monitoring that the rotating speed of the engine is 1380rpm which is less than the activation rotating speed of the oxygen removal 4000rpm and the ECU monitors that the catalyst is not in an OBD (on-board diagnostics) state, so that basic conditions of the catalyst oxygen removal are met;
(2) when the basic condition described in the step (1) is satisfied, it is judged whether or not a catalyst oxygen storage calculation start condition is satisfied, in which the oxygen storage calculation start excess air ratio λ11.25, the oxygen storage calculation limit duration T is 0.5 s;
when the fuel cut-off working condition occurs in the running process of the vehicle, such as the sudden acceleration pedal reception, and the fuel cut-off working condition lasts for 1.3s, the fuel supply is recovered, the monitored value of the front excess air coefficient of the catalyst is rapidly increased to 16 and lasts for 1.3s, and the condition that the excess air coefficient monitored by the front oxygen sensor of the catalyst is higher than the value of the front excess air coefficient monitored by the front oxygen sensor of the catalyst and the oxygen storage calculation is startedAir volume coefficient lambda1And the duration is greater than the oxygen storage calculation starting condition of the catalyst of the oxygen storage calculation limit duration T, the ECU starts to calculate the oxygen storage amount of the catalyst;
(3) when the starting condition of the step (2) is met, adopting an integral calculation mode according to a formula
Figure BDA0002336542100000151
Calculating the oxygen storage amount of the catalyst, wherein the oxygen storage calculation of the condition a ends the excess air coefficient lambda2＝1；
Value of excess air coefficient lambda monitored by pre-catalyst oxygen sensor at the start of catalyst oxygen storage calculationLeanIs 16; the condition for finishing the oxygen storage calculation of the catalyst is that after the fuel cut-off working condition continues for 1.3s and the fuel supply is recovered, the excess air coefficient monitored by the oxygen sensor in front of the catalyst is 0.99 which is lower than the excess air coefficient lambda after the oxygen storage calculation is finished2(ii) a As shown in FIG. 5, catalyst intake flow rate mairAlthough the continuous change is carried out within 1.3s of the continuous working condition of fuel cut-off, the continuous change is about 8.7kg/h, and finally the oxygen storage quantity M of the catalytic converter obtained by integral calculationOxy0.99 g;
(4) when the oxygen-removing condition of the catalyst is met, adopting an integral calculation mode according to a formula
Figure BDA0002336542100000152
Calculating the amount of catalyst oxygen and performing oxygen-cleaning operation, wherein the oxygen-cleaning begins to have excess air coefficient lambda40.995, an excess air coefficient value λ corresponding to a target air-fuel ratio for the oxygen scavenging processDesCase b' minimum catalyst oxygen purge M ═ 0.93PurgeLimit0.2g, case b' said purge end air excess factor λ50.99, case c' the multiple k is 1;
when the engine finishes fuel cut and resumes fuel supply, the end condition of the oxygen storage amount calculation of the catalyst in the step (3) meets the catalyst oxygen cleaning condition in the step (4), namely the excess air coefficient monitored by the oxygen sensor in front of the catalyst is 0.99 lower than the initial excess air coefficient lambda of cleaning oxygen4The ECU begins to calculate the oxygen content M of the catalystOxyPurgeAnd performing catalysisOxygen removal operation of the device; the catalyst oxygen cleaning amount M is obtained by integral calculation of the catalyst oxygen cleaning amount which is as long as 3.5sOxyPurge0.995g, where, as shown in FIG. 5, the catalyst inlet flow rate mairGradually increasing in 3.5s of the oxygen cleaning process, wherein the oxygen cleaning process gradually increases from 8.5kg/h to 30 kg/h; because the excess air coefficient detected by the oxygen sensor behind the catalyst at the end of the oxygen cleaning is 1.01, which is still larger than the excess air coefficient lambda at the end of the oxygen cleaning5Does not satisfy MOxyPurgeGreater than MPurgeLimitAnd the value of the post-catalyst excess air coefficient is less than lambda5Case b 'of (1), the oxygen-purging end condition of the present embodiment is case c', that is, MOxyPurge＞k*MOxy。
It can be seen from fig. 6 corresponding to this embodiment that, in the oxygen purging process, the value of the actual excess air coefficient before the catalyst is reduced from 1 to 0.94, and then the actual excess air coefficient is restored to the normal value of 1 again, so that the excessive oxygen in the catalyst is purged accurately and efficiently.
It should be noted that the air excess factor curves of fig. 4 and 6 of the present invention are not actually monitored values, but are stored values after being programmed by a computer.
The embodiment shows that the oxygen cleaning method is based on the physical model of the oxygen storage and cleaning process of the catalyst, and the excessive oxygen in the catalyst can be cleaned by accurately and efficiently controlling the fuel injection quantity through mathematical derivation. Moreover, the control parameters of the oxygen cleaning method mainly depend on the characteristics of an engine system, so that the time required by calibration can be saved, and the application scene is wider. The oxygen cleaning method is suitable for gasoline engines and motor vehicles provided with components such as a catalyst front oxygen sensor, a three-way catalyst, a catalyst rear oxygen sensor, an ECU controller and the like, is particularly suitable for the working conditions that the gasoline engine is cut off and oil supply and the air-fuel ratio is continuously leaner, can accurately and efficiently control the oil injection quantity to clean redundant oxygen in the catalyst, and ensures that the catalyst can rapidly recover the state of high-efficiency conversion of emissions.
The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims (10)

1. The oxygen cleaning method for the gasoline engine catalyst is characterized by comprising the following steps:
(1) judging whether the basic oxygen-cleaning condition of the catalyst is met;
(2) when the basic condition in the step (1) is met, judging whether a catalyst oxygen storage calculation starting condition is met;
(3) when the starting condition in the step (2) is met, calculating the oxygen storage amount of the catalyst;
(4) when the catalyst oxygen cleaning condition is met, calculating the catalyst oxygen cleaning amount and performing oxygen cleaning operation;
when the step (1) or the step (2) does not meet the corresponding condition, directly ending;
and (5) when the catalyst oxygen cleaning condition is not met in the step (4), continuously judging the condition.
2. The oxygen purging method according to claim 1, wherein the catalyst purge basic condition being satisfied in step (1) means that the engine speed is less than the purge activation speed and that the monitoring of the catalyst by the engine control unit ECU is not in the on-board diagnosis OBD state.
3. The oxygen cleaning method according to claim 1 or 2, wherein satisfying the catalyst oxygen storage calculation start condition of step (2) means that an excess air coefficient monitored by a pre-catalyst oxygen sensor is higher than an oxygen storage calculation start excess air coefficient λ1And the duration is greater than the calculated limit duration of oxygen storage T.
4. The oxygen cleaning method according to any one of claims 1 to 3, wherein the step (3) calculates the oxygen storage amount of the catalyst by means of integral calculation;
preferably, the integral calculation is formulated as:
Figure FDA0002336542090000011
wherein M isOxyThe oxygen storage capacity of the catalyst is g;
λLeancalculating an excess air factor value monitored by a pre-catalyst oxygen sensor at a start condition for catalyst oxygen storage;
mairthe unit is the catalyst inlet flow in kg/h.
5. The oxygen cleaning method according to any one of claims 1 to 4, wherein when the end condition of calculating the oxygen storage amount of the catalyst in step (3) is satisfied, the calculation of the catalyst oxygen cleaning amount in step (3) is terminated, the judgment of the oxygen cleaning condition of the catalyst in step (4) is started, otherwise, the calculation of the catalyst oxygen cleaning amount is continued;
preferably, any one of the following conditions is regarded as the end condition of calculating the oxygen storage amount of the catalyst in step (3):
case a: catalytic pre-oxygenThe excess air coefficient monitored by the sensor is lower than the excess air coefficient lambda of the oxygen storage calculation end2；
Case b: the oxygen storage amount of the catalyst reaches a saturated state;
preferably, case b again includes b1And b2Two cases are:
case b1: the oxygen storage amount of the catalyst obtained by calculation is larger than the limit oxygen storage amount M of the catalystOxyStorage；
Case b2: the excess air coefficient monitored by the oxygen sensor behind the catalyst is higher than the catalyst oxygen storage saturation excess air coefficient lambda3。
6. The oxygen cleaning method according to any one of claims 1 to 5, wherein the satisfaction of the catalyst cleaning condition in step (4) means that the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the initial excess air coefficient λ of cleaning oxygen4。
7. The oxygen cleaning method according to any one of claims 1 to 6, wherein the step (4) calculates the catalyst oxygen cleaning amount by means of integral calculation;
preferably, the integral calculation is formulated as:
Figure FDA0002336542090000021
wherein M isOxyPurgeThe unit is g and is the oxygen cleaning amount of the catalyst;
λDesan excess air coefficient value corresponding to a target air-fuel ratio for the oxygen scavenging process;
mairthe unit is the catalyst inlet flow in kg/h.
8. The oxygen cleaning method according to any one of claims 1 to 7, wherein the end condition of step (4) is considered when any one of the following conditions is satisfied:
a case a': if the catalyst oxygen storage calculation starting condition in the step (2) is met, re-executing the catalyst oxygen storage calculation in the step (3), otherwise, continuing to judge the condition b 'and the condition c';
case b': the catalyst oxygen cleaning amount is larger than the minimum catalyst oxygen cleaning amount MPurgeLimitAnd the excess air ratio monitored by the post-catalyst oxygen sensor is lower than the end-of-purge-oxygen excess air ratio lambda5；
In the case c': the oxygen storage amount of the catalyst obtained in the step (3) is larger than k times of the oxygen cleaning amount of the catalyst;
preferably, the multiple k in case c' is 1 to 1.5;
preferably, when the condition b 'or the condition c' is satisfied, not only the end condition of the step (4) but also a mark of the end of the whole oxygen cleaning method is considered; when the condition b 'and the condition c' are not satisfied, continuing to calculate the catalyst oxygen cleaning amount and performing the oxygen cleaning operation in the step (4).
9. The method according to any one of claims 1 to 8, wherein the oxygen purging operation of step (4) sets an excess air ratio λ corresponding to a target air-fuel ratioaimAdding a concentrated mixed gas;
preferably, the rich mixture is rich-compensated via an air-fuel ratio closed-loop control function.
10. The oxygen cleaning method according to any one of claims 1 to 9, wherein the oxygen cleaning method comprises the steps of:
(1) judging whether the basic oxygen-cleaning condition of the catalyst is met;
wherein, the condition that the basic oxygen cleaning condition of the catalyst is met means that the engine speed is less than the oxygen cleaning activation speed and the monitoring state of the on-board diagnosis OBD of the catalyst is not monitored by an engine control unit ECU;
(2) when the basic condition in the step (1) is met, judging whether a catalyst oxygen storage calculation starting condition is met;
wherein satisfying the catalyst oxygen storage calculation start condition means that an excess air ratio monitored by a pre-catalyst oxygen sensor is higher than an excess air ratio monitored by a pre-catalyst oxygen sensor when oxygen storage calculation start is performedExcess air factor lambda1And the duration is greater than the calculated limit duration T of oxygen storage;
(3) when the starting condition of the step (2) is met, adopting an integral calculation mode according to a formula
Figure FDA0002336542090000041
Calculating oxygen storage amount of the catalyst, terminating the calculation of the oxygen cleaning amount of the catalyst when the ending condition of calculating the oxygen storage amount of the catalyst is met, starting to judge the oxygen cleaning condition of the catalyst in the step (4), and otherwise, continuing to calculate the oxygen cleaning amount of the catalyst;
wherein, any one of the following conditions is regarded as the end condition for calculating the oxygen storage amount of the catalyst:
case a: the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the calculated excess air coefficient lambda2；
Case b: the oxygen storage amount of the catalyst reaches a saturated state;
(4) when the excess air coefficient monitored by the pre-catalyst oxygen sensor is lower than the initial excess air coefficient lambda of the clean oxygen4Considering that the oxygen removal condition of the catalyst is met, adopting an integral calculation mode according to a formula
Figure FDA0002336542090000042
Calculating the oxygen cleaning amount of the catalyst, and simultaneously setting an excess air coefficient lambda corresponding to a target air-fuel ratioaimThe enrichment compensation of the mixed gas is realized through the closed-loop control function of the air-fuel ratio;
wherein, when any one of the following conditions is satisfied, the condition is regarded as the end condition of the step (4):
a case a': if the catalyst oxygen storage calculation starting condition in the step (2) is met, re-executing the catalyst oxygen storage calculation in the step (3), otherwise, continuing to judge the condition b 'and the condition c';
case b': the catalyst oxygen cleaning amount is larger than the minimum catalyst oxygen cleaning amount MPurgeLimitAnd the excess air ratio monitored by the post-catalyst oxygen sensor is lower than the end-of-purge-oxygen excess air ratio lambda5；
In the case c': the oxygen storage amount of the catalyst obtained in the step (3) is larger than k times of the oxygen cleaning amount of the catalyst;
when the condition b 'or the condition c' is met, the condition is not only considered as the ending condition of the step (4), but also as a mark for ending the whole oxygen cleaning method; when the condition b 'and the condition c' are not satisfied, continuing to calculate the catalyst oxygen cleaning amount and performing the oxygen cleaning operation in the step (4).
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111779556A (en) * 2020-06-30 2020-10-16 东风汽车集团有限公司 Control method for oxygen removal of gasoline engine catalyst
CN111997725A (en) * 2020-09-09 2020-11-27 东风汽车有限公司 Vehicle-mounted catalytic converter abnormity diagnosis and electronic equipment
CN113323747A (en) * 2021-06-23 2021-08-31 东风汽车有限公司东风日产乘用车公司 Abnormality diagnosis of catalytic converter and electronic device
CN115111036A (en) * 2021-03-19 2022-09-27 日立安斯泰莫汽车系统(苏州)有限公司 Oil cut-off control method, device and system and storage medium
CN115217659A (en) * 2022-06-17 2022-10-21 天津大学 Gasoline engine fuel injection quantity control method based on three-way catalyst oxygen storage state monitoring result
CN116220929A (en) * 2023-01-03 2023-06-06 广州汽车集团股份有限公司 Automobile control method, device, terminal and medium

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020152743A1 (en) * 2000-02-16 2002-10-24 Takeshi Nakamura Engine exhaust purification device
JP2005201112A (en) * 2004-01-14 2005-07-28 Toyota Motor Corp Fuel injection control device for internal combustion engine
US20090288391A1 (en) * 2006-06-27 2009-11-26 Keiichiro Aoki Catalyst deterioration detection device
KR20100044531A (en) * 2008-10-22 2010-04-30 현대자동차주식회사 System and method for catalyst purge control
US20120031178A1 (en) * 2010-08-07 2012-02-09 Audi Ag Method for determining the oxygen storage capacity of a catalytic converter
CN104141524A (en) * 2013-05-10 2014-11-12 福特环球技术公司 Integrated fuel catalyst monitor
CN104234798A (en) * 2013-06-06 2014-12-24 通用汽车环球科技运作有限责任公司 Method for the load dependent reduction of fuel consumption following deceleration fuel cut out
CN104727906A (en) * 2013-12-18 2015-06-24 现代自动车株式会社 Exhaust gas purifying system for vehicle
CN109057927A (en) * 2018-08-01 2018-12-21 奇瑞汽车股份有限公司 Method for calculating oxygen storage capacity of catalyst
CN110259553A (en) * 2019-06-28 2019-09-20 潍柴动力股份有限公司 A kind of calculation method, device and the electronic equipment of ternary catalyzing unit oxygen storage capacity

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020152743A1 (en) * 2000-02-16 2002-10-24 Takeshi Nakamura Engine exhaust purification device
JP2005201112A (en) * 2004-01-14 2005-07-28 Toyota Motor Corp Fuel injection control device for internal combustion engine
US20090288391A1 (en) * 2006-06-27 2009-11-26 Keiichiro Aoki Catalyst deterioration detection device
KR20100044531A (en) * 2008-10-22 2010-04-30 현대자동차주식회사 System and method for catalyst purge control
US20120031178A1 (en) * 2010-08-07 2012-02-09 Audi Ag Method for determining the oxygen storage capacity of a catalytic converter
CN104141524A (en) * 2013-05-10 2014-11-12 福特环球技术公司 Integrated fuel catalyst monitor
CN104234798A (en) * 2013-06-06 2014-12-24 通用汽车环球科技运作有限责任公司 Method for the load dependent reduction of fuel consumption following deceleration fuel cut out
CN104727906A (en) * 2013-12-18 2015-06-24 现代自动车株式会社 Exhaust gas purifying system for vehicle
CN109057927A (en) * 2018-08-01 2018-12-21 奇瑞汽车股份有限公司 Method for calculating oxygen storage capacity of catalyst
CN110259553A (en) * 2019-06-28 2019-09-20 潍柴动力股份有限公司 A kind of calculation method, device and the electronic equipment of ternary catalyzing unit oxygen storage capacity

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111779556A (en) * 2020-06-30 2020-10-16 东风汽车集团有限公司 Control method for oxygen removal of gasoline engine catalyst
CN111779556B (en) * 2020-06-30 2021-10-15 东风汽车集团有限公司 Control method for oxygen removal of gasoline engine catalyst
CN111997725A (en) * 2020-09-09 2020-11-27 东风汽车有限公司 Vehicle-mounted catalytic converter abnormity diagnosis and electronic equipment
CN111997725B (en) * 2020-09-09 2022-01-07 东风汽车有限公司 Vehicle-mounted catalytic converter abnormity diagnosis and electronic equipment
CN115111036A (en) * 2021-03-19 2022-09-27 日立安斯泰莫汽车系统(苏州)有限公司 Oil cut-off control method, device and system and storage medium
CN113323747A (en) * 2021-06-23 2021-08-31 东风汽车有限公司东风日产乘用车公司 Abnormality diagnosis of catalytic converter and electronic device
CN115217659A (en) * 2022-06-17 2022-10-21 天津大学 Gasoline engine fuel injection quantity control method based on three-way catalyst oxygen storage state monitoring result
CN115217659B (en) * 2022-06-17 2024-02-09 天津大学 Gasoline engine fuel injection quantity control method based on monitoring result of oxygen storage state of three-way catalyst
CN116220929A (en) * 2023-01-03 2023-06-06 广州汽车集团股份有限公司 Automobile control method, device, terminal and medium
CN116220929B (en) * 2023-01-03 2024-04-16 广州汽车集团股份有限公司 Automobile control method, device, terminal and medium

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