CN114856841A - GPF regeneration control method based on two-point oxygen sensor - Google Patents
GPF regeneration control method based on two-point oxygen sensor Download PDFInfo
- Publication number
- CN114856841A CN114856841A CN202210249313.5A CN202210249313A CN114856841A CN 114856841 A CN114856841 A CN 114856841A CN 202210249313 A CN202210249313 A CN 202210249313A CN 114856841 A CN114856841 A CN 114856841A
- Authority
- CN
- China
- Prior art keywords
- fuel ratio
- air
- gpf
- fuel injection
- injection quantity
- 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
Links
Images
Classifications
-
- 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
- F01N9/00—Electrical control of exhaust gas treating apparatus
- F01N9/002—Electrical control of exhaust gas treating apparatus of filter regeneration, e.g. detection of clogging
-
- 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
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
-
- 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
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
- F02D41/029—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a particulate filter
-
- 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
- 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
-
- 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)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
The invention provides a GPF regeneration control method based on a two-point oxygen sensor, which comprises the following steps: when the engine runs to a GPF renewable region, performing closed-loop control on the actual air-fuel ratio by using a pre-controlled fuel injection quantity model, and performing self-learning on the average value of closed-loop fuel injection correction factors output by the pre-controlled fuel injection quantity model until the average value of the closed-loop fuel injection correction factors reaches a target value; correcting the pre-controlled fuel injection quantity model by using a self-learning value stored when self-learning is finished; and inputting an air-fuel ratio test signal into the corrected pre-controlled fuel injection quantity model, judging whether a voltage signal output by the two-point type sensor meets the requirement, and if so, starting GPF regeneration control. Compared with the prior art, the GPF regeneration control method based on the two-point oxygen sensor provided by the invention has the advantages that the requirement on the GPF regeneration control precision is ensured, and the cost of the whole vehicle is reduced.
Description
Technical Field
The invention relates to the technical field of vehicles, in particular to a GPF regeneration control method based on a two-point oxygen sensor.
Background
With the implementation of the regulations GB18352.6-2016 emission limits and measurement methods for light vehicle pollutants (sixth stage of china), in order to meet the newly increased emission requirements for Particulate matter, particle traps (GPF) are added to exhaust gas aftertreatment devices for more and more light vehicles.
The main component of particulate matter in automobile exhaust is carbon (soot), which is a product of insufficient combustion of gasoline. When the carbon deposition amount of GPF is too high, the following effects are mainly brought about:
1) the exhaust back pressure of the engine is too high, so that the power is insufficient;
2) under the high-speed and large-load working condition, the pressure difference between two ends of the GPF exceeds a threshold value, so that the carrier liner slides;
3) in the vicinity of the engine external characteristic point, the exhaust back pressure is too high, and the turbocharger turbine speed exceeds the limit value.
Therefore, when the conditions are appropriate, an Engine Management System (EMS) controls the implementation of the secondary combustion of the root, i.e., regeneration; the conditions for regeneration include two: firstly, the temperature of GPF exceeds 580 ℃; and secondly, the automobile exhaust is in an oxygen-enriched state.
The combustion speed of GPF carbon deposition is related to three factors:
1) the current carbon deposition amount of GPF;
2) the temperature of the GPF support;
3) oxygen content in the exhaust gas flowing through GPF, i.e. oxygen flow.
In order to accurately monitor the combustion condition of the root and realize accurate calculation of the carbon deposition amount of the GPF, an EMS system needs to establish a combustion rate model (root burn model) of the root; the primary inputs to the burn rate model are the temperature of the GPF carrier and the oxygen flow through the GPF.
Currently, a typical GPF regeneration arrangement is shown in fig. 1. In fig. 1:
the system comprises an LSU, a linear oxygen sensor, a catalytic converter (TWC) and a gas-fuel ratio sensor, wherein the LSU is arranged at the outlet of an exhaust manifold and at the front end of the TWC and is used for monitoring the mass ratio of air and fuel (namely the air-fuel ratio lambda) of an engine participating in combustion; the range of the air-fuel ratio measured by the linear oxygen sensor is generally 0.7-16 (pure air);
the temperature Sensor is arranged at the inlet of the GPF, measures the exhaust temperature at the inlet of the GPF and is used for establishing a GPF carrier temperature model;
and the DP Sensor, the differential pressure Sensor and the pressure sampling points are respectively arranged at the inlet and the outlet of the GPF and used for monitoring the differential pressure at two ends of the GPF and diagnosing whether the GPF carrier is damaged or falls off.
After the linear oxygen sensor is configured, theoretically, the EMS can realize closed-loop control of any point between 0.7 and 16 (pure air) of the air-fuel ratio, so that the air-fuel ratio is accurately controlled, and the aim of ensuring accurate oxygen flow calculation is fulfilled.
Generally, the EMS air-fuel ratio closed-loop control strategy is shown in FIG. 2. Wherein λ target represents a target air-fuel ratio; λ actual represents an actual air-fuel ratio; the system performs PID control on the actual air-fuel ratio, and the output is a closed-loop oil injection correction factor fr.
When lambda actual is larger than lambda target, increasing the oil injection quantity of the engine, namely multiplying a closed-loop oil injection correction factor (fr, larger than 1) on the basis of the pre-controlled oil injection quantity, thereby realizing the increase of the oil injection quantity; and when the lambda actual is smaller than the lambda target, reducing the fuel injection quantity of the engine, namely multiplying a closed-loop fuel injection correction factor (fr, smaller than 1) on the basis of the pilot-controlled fuel injection quantity, thereby realizing the reduction of the fuel injection quantity.
In addition, fuel injection quantity is pre-controlled, and EMS calculates in real time according to the current running state of the engine based on a fuel injection quantity model established in advance; due to the vehicle divergence, oil factors and the accuracy of the model, the pre-controlled fuel injection quantity needs to be corrected in real time through closed-loop control to ensure that the air-fuel ratio is always controlled near a target value.
Disclosure of Invention
At present, the cost of a linear oxygen sensor (LSU) is higher than that of a two-point oxygen sensor (LSF), and if the two-point oxygen sensor is used for replacing the linear oxygen sensor, the requirement of reducing the cost of the whole vehicle of a host factory can be met. However, as previously mentioned, in general, GDP regeneration control strategies are generally based on linear sensor deployment. The inventors have studied and found that when GDP regeneration is performed by a two-point sensor, if the target air-fuel ratio is out of a certain range, the control accuracy is not high.
In view of the above, an object of the present invention is to provide a GPF regeneration control method based on a two-point oxygen sensor, so as to solve the problem that when GPF regeneration control is performed by using the two-point oxygen sensor, the GPF regeneration control accuracy is not high under some target air-fuel conditions.
In order to solve the above technical problems, the present invention provides a GPF regeneration control method based on a two-point oxygen sensor, including:
when the engine runs to a GPF renewable region, performing closed-loop control on the actual air-fuel ratio by using a pre-controlled fuel injection quantity model, and performing self-learning on the average value of closed-loop fuel injection correction factors output by the pre-controlled fuel injection quantity model until the average value of the closed-loop fuel injection correction factors reaches a target value;
correcting the pre-controlled fuel injection quantity model by using a self-learning value stored when self-learning is finished; and the number of the first and second groups,
inputting an air-fuel ratio test signal into the corrected pre-controlled fuel injection quantity model, judging whether a voltage signal output by the two-point type sensor meets the requirement, and if so, starting GPF regeneration control.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the method for inputting an air-fuel ratio test signal to the corrected predicted fuel injection quantity to determine whether a voltage signal output by the two-point oxygen sensor meets a requirement includes:
inputting a first air-fuel ratio which is leaner than the original air-fuel ratio into the pre-control fuel injection quantity model as a target air-fuel ratio and continuously setting time, and then inputting a second air-fuel ratio which is richer than the original air-fuel ratio into the pre-control fuel injection quantity model as a target air-fuel ratio and continuously setting the same time;
and judging whether the output voltage of the two-point type oxygen sensor is smaller than a first voltage value or not after the first air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model, and whether the output voltage of the two-point type oxygen sensor is larger than a second voltage value or not after the second air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the method for inputting an air-fuel ratio test signal to the corrected predicted fuel injection quantity to determine whether a voltage signal output by the two-point oxygen sensor meets a requirement includes:
inputting a second air-fuel ratio which is rich as a target air-fuel ratio into the pre-control fuel injection quantity model and continuing for a set time, and then stepping to input a first air-fuel ratio which is lean as a target air-fuel ratio into the pre-control fuel injection quantity model and continuing for the same set time;
and judging whether the output voltage of the two-point type oxygen sensor is smaller than a first voltage value or not after the first air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model, and whether the output voltage of the two-point type oxygen sensor is larger than a second voltage value or not after the second air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the first air-fuel ratio is greater than 1.03, and the second air-fuel ratio is less than 0.97.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the first air-fuel ratio is 1.055, the second air-fuel ratio is 0.945, the first voltage value is 0.078V, and the second voltage value is 0.8V.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the method for performing closed-loop control on the actual air-fuel ratio by using the pre-controlled fuel injection quantity model and performing self-learning on the average value of the closed-loop fuel injection correction factor output by the pre-controlled fuel injection quantity model includes:
after a target air-fuel ratio which is leaner or richer is input into the pre-control fuel injection quantity model, the actual air-fuel ratio measured by the two-point type oxygen sensor is continuously 1 to serve as a self-learning condition, and the average value of the closed-loop fuel injection correction factors is self-learned until the average value of the closed-loop fuel injection correction factors reaches a target value.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, a value range of the target value is [0.995, 1.005 ].
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the method further includes:
dividing different rotating speeds and torques of the engine into regions;
and classifying the corresponding area into a GPF reproducible area or a GPF non-reproducible area according to the GPF carrier temperature corresponding to each area.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the method for classifying the corresponding region as a GPF renewable region or a GPF non-renewable region according to the GPF carrier temperature corresponding to each region includes:
if the temperature of the GPF carrier corresponding to the area is more than 650 ℃, the area is classified as a GPF renewable area;
if the GPF carrier temperature corresponding to the area is more than 650 ℃, the area is classified as a GPF non-renewable area.
Optionally, in the GPF regeneration control method based on the two-point oxygen sensor, the target air-fuel ratio for GPF regeneration control is set to 1.08.
In summary, the GPF regeneration control method based on the two-point oxygen sensor according to the present invention includes: when the engine runs to a GPF renewable region, performing closed-loop control on the actual air-fuel ratio by using a pre-controlled fuel injection quantity model, and performing self-learning on the average value of closed-loop fuel injection correction factors output by the pre-controlled fuel injection quantity model until the average value of the closed-loop fuel injection correction factors reaches a target value; correcting the pre-controlled fuel injection quantity model by using a self-learning value stored when self-learning is finished; and inputting an air-fuel ratio test signal into the corrected pre-controlled fuel injection quantity model, judging whether a voltage signal output by the two-point type sensor meets the requirement, and if so, starting GPF regeneration control. Compared with the prior art, the method has the following beneficial effects:
the engine operation area is divided into a plurality of renewable and non-renewable areas, closed-loop self-learning is carried out in each renewable area to correct air-fuel ratio control deviation caused by vehicle dispersion, oil factors, a pre-control fuel injection quantity model and the like, and the two-point type oxygen sensor is more economical and practical compared with a linear oxygen sensor, so that the GPF regeneration control method based on the two-point type oxygen sensor provided by the invention can ensure the GPF regeneration control accuracy requirement and also reduce the whole vehicle cost.
Drawings
FIG. 1 is a schematic diagram of a typical GPF regeneration arrangement;
FIG. 2 is a schematic diagram of an EMS air-fuel ratio closed-loop control strategy;
FIG. 3 is a diagram illustrating a relationship between an actual air-fuel ratio λ and a voltage signal uskv according to an embodiment of the present invention;
FIG. 4 is a flowchart of a GPF regeneration control method based on a two-point oxygen sensor according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating region partitioning according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a self-learning process in an embodiment of the present invention;
fig. 7 is a process diagram of an embodiment of a GPF regeneration control method based on a two-point oxygen sensor according to the present invention.
Detailed Description
To make the objects, advantages and features of the present invention more apparent, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It is to be noted that the drawings are in greatly simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently. It should be further understood that the terms "first," "second," "third," and the like in the description are used for distinguishing between various components, elements, steps, and the like, and are not intended to imply a logical or sequential relationship between various components, elements, steps, or the like, unless otherwise indicated or indicated.
When the two-point sensor is used for detecting the actual air-fuel ratio lambda, the output of the two-point sensor is a voltage signal uskv of 0-1V. The inventors have found that there is a correspondence between λ and the voltage signal uskv as shown in fig. 3.
As can be seen from fig. 3, the voltage signal uskv of the two-point oxygen sensor changes in steps around the air-fuel ratio of 1; in the region where the air-fuel ratio is less than 0.97 and greater than 1.03, the voltage signal usvk tends to be stable with the change in the air-fuel ratio, and therefore, only a richer or leaner air-fuel ratio can be reflected in the region where the air-fuel ratio is less than 0.97 and greater than 1.03. The voltage of the thick end (lambda is less than 1) is more than 0.68V, and the voltage of the thin end (lambda is more than 1) is less than 0.2V.
When the air-fuel ratio is near 1, because the voltage signal uskv is in step change, a more accurate actual air-fuel ratio can be obtained based on the voltage signal uskv, so when the air-fuel ratio is near 1, when the air-fuel ratio is identified to be richer, the closed-loop oil injection correction factor fr is adjusted to the lean end; and when the air-fuel ratio is identified to be lean, adjusting the closed-loop oil injection correction factor fr to a rich end.
That is, for the two-point oxygen sensor, it can only realize the closed-loop control that the target air-fuel ratio is near 1, when the target air-fuel ratio is not near 1, only the open-loop control can be performed, that is, only the new pilot-controlled fuel injection quantity can be obtained by dividing the target air-fuel ratio by the pilot-controlled fuel injection quantity, so as to realize the control of the target air-fuel ratio; the accuracy of actual air-fuel ratio control completely depends on the accuracy of the pre-controlled fuel injection quantity model. Therefore, if the required target air-fuel ratio is not near 1 during GPF regeneration, a two-point oxygen sensor is adopted, so that the effective control of the fuel ratio during regeneration is difficult, the oxygen flow cannot be accurately calculated, and finally the deviation of the soot combustion rate model is caused.
Based on the above research of the inventor, as shown in fig. 4, an embodiment of the present invention provides a GPF regeneration control method based on a two-point oxygen sensor, including the steps of:
s11, when the engine runs to a certain GPF renewable region, performing closed-loop control on the actual air-fuel ratio by using a pre-control oil injection quantity model, and performing self-learning on the average value of closed-loop oil injection correction factors output by the pre-control oil injection quantity model until the average value of the closed-loop oil injection correction factors reaches a target value;
s12, correcting the pre-controlled fuel injection quantity model by using the self-learning value stored when the self-learning is finished;
and S13, inputting an air-fuel ratio test signal into the corrected pre-controlled fuel injection quantity model, judging whether a voltage signal output by the two-point type sensor meets the requirement, and if so, starting GPF regeneration control.
The above steps are described in detail.
In step S11, the GPF renewable region is divided according to the GPF carrier temperature corresponding to the specific operating condition of the engine. Specifically, the division process is as follows: dividing different rotating speeds and torques of the engine into regions; and classifying the corresponding region into a GPF reproducible region or a GPF non-reproducible region according to the GPF carrier temperature corresponding to each region (if the GPF carrier temperature corresponding to the region is more than 650 ℃, the region is classified into the GPF reproducible region, and if the GPF carrier temperature corresponding to the region is more than 650 ℃, the region is classified into the GPF non-reproducible region).
One of the early conditions for GPF regeneration is that the carrier temperature reaches a suitable temperature, typically above 580 ℃; therefore, not all the speed and torque regions in which the engine is operated are suitable for regeneration, so as shown in fig. 5, the engine can be divided into a plurality of regions according to the universal characteristic curve of the engine (collecting the GPF carrier temperature under different speed and torque conditions), each region is divided into a renewable region and an nonrenewable region according to the GPF carrier temperature in the region, and in fig. 5, N represents the nonrenewable region; y represents a reproducible region.
After GPF renewable and nonregenerative regions are divided according to the operating condition of the engine, closed-loop self-learning is carried out on each GPF renewable region to correct air-fuel ratio control deviation caused by vehicle dispersion, oil factors, a pre-control fuel injection quantity model and the like.
Firstly, step S11 is executed, when the engine is operated to a certain GPF regeneration region, in this region, the pre-controlled fuel injection quantity model is used to perform closed-loop control on the actual air-fuel ratio, and the average value frm of the closed-loop fuel injection correction factor fr output by the pre-controlled fuel injection quantity model is self-learned, and the self-learned value fra is stored, and the self-learning continues until frm is a target value, and the value range of the target value is [0.995, 1.005], for example, 1. Then, step S12 is executed to correct the pilot fuel injection amount model using the self-learning value fra stored at the end of self-learning. Whether the deviation is caused by vehicle dispersion, oil factors or a pre-control oil injection quantity model; the corrected pre-controlled fuel injection quantity model can theoretically ensure that the accurate control of the target air-fuel ratio is realized in an open loop state.
Referring to fig. 6, in step S11 of this embodiment, the method for performing closed-loop control on the actual air-fuel ratio by using the pilot injection quantity model and performing self-learning on the average value of the closed-loop injection correction factor output by the pilot injection quantity model may include:
after a leaner target air-fuel ratio (the air-fuel ratio is larger than 1.03) is input into the pre-control fuel injection quantity model, the actual air-fuel ratio measured by the two-point oxygen sensor is continuously 1 to serve as a self-learning condition, and the average value of the closed-loop fuel injection correction factor is self-learned until the average value of the closed-loop fuel injection correction factor reaches a target value. Fig. 5 shows an example of a regeneration condition where a certain pilot fuel injection amount is relatively lean by 5% (i.e., fr is initially 1.05), and the target value is 1.
In some other embodiments, step S11, the method for performing closed-loop control on the actual air-fuel ratio by using the pilot injection quantity model and performing self-learning on the average value of the closed-loop injection correction factor output by the pilot injection quantity model may include:
after a leaner target air-fuel ratio (the air-fuel ratio is less than 0.97) is input into the pre-control fuel injection quantity model, the actual air-fuel ratio measured by the two-point oxygen sensor is continuously 1 to serve as a self-learning condition, and the average value of the closed-loop fuel injection correction factors is self-learned until the average value of the closed-loop fuel injection correction factors reaches a target value.
Next, step S13 is executed to detect the accuracy of the corrected pilot-controlled fuel injection quantity model, generate an air-fuel ratio test signal based on the air-fuel ratio characteristics (air-fuel ratio-voltage relationship) of the two-point oxygen sensor, input the air-fuel ratio test signal to the corrected pilot-controlled fuel injection quantity model, and then determine whether the output voltage of the two-point oxygen sensor meets the requirement.
In an optional implementation mode, a first lean air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model for a set time, and then a second rich air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model for the same set time in a stepped mode; and judging whether the output voltage of the two-point type oxygen sensor is smaller than a first voltage value after the first air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model, and judging whether the output voltage of the two-point type oxygen sensor is larger than a second voltage value after the second air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model.
In another optional embodiment, the second air-fuel ratio which is rich is taken as the target air-fuel ratio and is input into the pre-control fuel injection quantity model for a set time, and then the first air-fuel ratio which is lean is taken as the target air-fuel ratio and is input into the pre-control fuel injection quantity model for the same set time in a stepped mode; and judging whether the output voltage of the two-point type oxygen sensor is smaller than a first voltage value after the first air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model, and judging whether the output voltage of the two-point type oxygen sensor is larger than a second voltage value after the second air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model.
In the two embodiments, the final output voltage meets the requirement, and the control deviation of the corrected pre-controlled fuel injection quantity model can be confirmed to be within 1%.
In order to be able to achieve the practical verification effect, the first air-fuel ratio may be set to be greater than 1.03, and the second air-fuel ratio may be set to be less than 0.97. Preferably, the first air-fuel ratio is 1.055, the second air-fuel ratio is 0.945, and correspondingly, the first voltage value is 0.078V, and the second voltage value is 0.8V. The inventors have found that, when the first air-fuel ratio is 1.055 and the second air-fuel ratio is 0.945, the corresponding voltage value is relatively stable at the time of output, and therefore, the robustness of detection of the corrected pilot-controlled fuel injection quantity model can be improved.
In this embodiment, in order to maximize the GPF regeneration rate, it is preferable to set the target air-fuel ratio for GPF regeneration control to 1.08, under which the engine can still operate stably, and after the air-fuel ratio is increased, engine hunting or engine stall due to poor engine combustion may occur.
In combination with the selection of the above specific values, as shown in fig. 7, in one embodiment, the GPF regeneration control method based on the two-point oxygen sensor provided in this embodiment roughly comprises the following processes:
when the engine is operated to a certain re-travelable region, closed-loop self-learning in the region is started, and a detection signal is generated after the self-learning in the region is completed to judge whether the output voltage is greater than 0.8V when the target air-fuel ratio is equal to 0.945 and whether the output voltage is less than 0.078V when the target air-fuel ratio is equal to 1.055, and if so, GPF regeneration control is started with the target air-fuel ratio being 1, 08.
In summary, the GPF regeneration control method based on the two-point oxygen sensor according to the present invention includes: when the engine runs to a GPF renewable region, performing closed-loop control on the actual air-fuel ratio by using a pre-controlled fuel injection quantity model, and performing self-learning on the average value of closed-loop fuel injection correction factors output by the pre-controlled fuel injection quantity model until the average value of the closed-loop fuel injection correction factors reaches a target value; correcting the pre-controlled fuel injection quantity model by using a self-learning value stored when self-learning is finished; and inputting an air-fuel ratio test signal into the corrected pre-controlled fuel injection quantity model, judging whether a voltage signal output by the two-point type sensor meets the requirement, and if so, starting GPF regeneration control. Compared with the prior art, has the beneficial effects that: the engine operation area is divided into a plurality of renewable and non-renewable areas, closed-loop self-learning is carried out in each renewable area to correct air-fuel ratio control deviation caused by vehicle dispersion, oil factors, a pre-control fuel injection quantity model and the like, and the two-point type oxygen sensor is more economical and practical compared with a linear oxygen sensor, so that the GPF regeneration control method based on the two-point type oxygen sensor provided by the invention can ensure the GPF regeneration control accuracy requirement and also reduce the whole vehicle cost.
It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the content of the technical solution of the present invention is departed from.
Claims (10)
1. A GPF regeneration control method based on a two-point oxygen sensor is characterized by comprising the following steps:
when the engine runs to a certain GPF renewable region, performing closed-loop control on the actual air-fuel ratio by using a pre-controlled fuel injection quantity model, and performing self-learning on the average value of closed-loop fuel injection correction factors output by the pre-controlled fuel injection quantity model until the average value of the closed-loop fuel injection correction factors reaches a target value;
correcting the pre-controlled fuel injection quantity model by using the self-learning value stored when the self-learning is finished; and the number of the first and second groups,
inputting an air-fuel ratio test signal into the corrected pre-controlled fuel injection quantity model, judging whether a voltage signal output by the two-point type sensor meets the requirement, and if so, starting GPF regeneration control.
2. The GPF regeneration control method based on the two-point oxygen sensor according to claim 1, wherein the method for inputting an air-fuel ratio test signal to the corrected predicted fuel injection amount to determine whether the voltage signal output by the two-point sensor satisfies the requirement comprises:
inputting a first air-fuel ratio which is leaner than the original air-fuel ratio into the pre-control fuel injection quantity model as a target air-fuel ratio and continuously setting time, and then inputting a second air-fuel ratio which is richer than the original air-fuel ratio into the pre-control fuel injection quantity model as a target air-fuel ratio and continuously setting the same time;
and judging whether the output voltage of the two-point type oxygen sensor is smaller than a first voltage value or not after the first air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model, and whether the output voltage of the two-point type oxygen sensor is larger than a second voltage value or not after the second air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model.
3. The GPF regeneration control method based on the two-point oxygen sensor according to claim 1, wherein the method for inputting an air-fuel ratio test signal to the corrected predicted fuel injection amount to determine whether the voltage signal output by the two-point sensor satisfies the requirement comprises:
inputting a second air-fuel ratio which is rich as a target air-fuel ratio into the pre-control fuel injection quantity model and continuing for a set time, and then stepping to input a first air-fuel ratio which is lean as a target air-fuel ratio into the pre-control fuel injection quantity model and continuing for the same set time;
and judging whether the output voltage of the two-point type oxygen sensor is smaller than a first voltage value or not after the first air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model, and whether the output voltage of the two-point type oxygen sensor is larger than a second voltage value or not after the second air-fuel ratio is taken as a target air-fuel ratio and input into the pre-control fuel injection quantity model.
4. The two-point oxygen sensor-based GPF regeneration control method of claim 2 or 3, wherein the first air-fuel ratio is greater than 1.03 and the second air-fuel ratio is less than 0.97.
5. The two-point sensor-based GPF regeneration control method of claim 4, wherein the first air-fuel ratio is 1.055, the second air-fuel ratio is 0.945, the first voltage value is 0.078V, and the second voltage value is 0.8V.
6. The GPF regeneration control method based on the two-point oxygen sensor according to claim 1, wherein the method for performing closed-loop control on the actual air-fuel ratio by using the pre-controlled injection quantity model and performing self-learning on the average value of the closed-loop injection correction factor output by the pre-controlled injection quantity model comprises the following steps:
after a target air-fuel ratio which is leaner or richer is input into the pre-control fuel injection quantity model, the actual air-fuel ratio measured by the two-point type oxygen sensor is continuously 1 to serve as a self-learning condition, and the average value of the closed-loop fuel injection correction factors is self-learned until the average value of the closed-loop fuel injection correction factors reaches a target value.
7. The GPF regeneration control method based on the two-point oxygen sensor according to claim 1 or 6, characterized in that the value of the target value ranges from [0.995, 1.005 ].
8. The GPF regeneration control method based on the two-point oxygen sensor according to claim 1, further comprising:
dividing different rotating speeds and torques of the engine into regions;
and classifying the corresponding area into a GPF reproducible area or a GPF non-reproducible area according to the GPF carrier temperature corresponding to each area.
9. The GPF regeneration control method based on the two-point oxygen sensor according to claim 8, wherein the method of classifying the corresponding region as a GPF reproducible region or a GPF non-reproducible region according to the GPF carrier temperature corresponding to each region comprises:
if the temperature of the GPF carrier corresponding to the area is more than 650 ℃, the area is classified as a GPF renewable area;
if the GPF carrier temperature corresponding to the area is more than 650 ℃, the area is classified as a GPF non-renewable area.
10. The GPF regeneration control method based on the two-point oxygen sensor according to claim 1, characterized in that the target air-fuel ratio at which the GPF regeneration control is performed is set to 1.08.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210249313.5A CN114856841B (en) | 2022-03-14 | 2022-03-14 | GPF regeneration control method based on two-point oxygen sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210249313.5A CN114856841B (en) | 2022-03-14 | 2022-03-14 | GPF regeneration control method based on two-point oxygen sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114856841A true CN114856841A (en) | 2022-08-05 |
| CN114856841B CN114856841B (en) | 2023-06-30 |
Family
ID=82627321
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210249313.5A Active CN114856841B (en) | 2022-03-14 | 2022-03-14 | GPF regeneration control method based on two-point oxygen sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114856841B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115788691A (en) * | 2022-11-30 | 2023-03-14 | 东风汽车集团股份有限公司 | Exhaust Gas Recirculation (EGR) rate optimization control method based on passive regeneration of General Purpose Filter (GPF) |
| CN115949524A (en) * | 2022-11-30 | 2023-04-11 | 东风汽车集团股份有限公司 | Exhaust Gas Recirculation (EGR) rate optimization control method based on GPF regeneration |
| CN116201647A (en) * | 2022-11-30 | 2023-06-02 | 东风汽车集团股份有限公司 | EGR rate optimization control method based on GPF active regeneration |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0490612A1 (en) * | 1990-12-10 | 1992-06-17 | Ford Motor Company Limited | Adaptive air/fuel ratio control method and system |
| WO1998055742A1 (en) * | 1997-06-03 | 1998-12-10 | Siemens Aktiengesellschaft | PROCESS FOR REGENERATING AN NOx ACCUMULATOR CATALYTIC CONVERTER |
| JP2001132514A (en) * | 1999-11-01 | 2001-05-15 | Tokyo Gas Co Ltd | Exhaust emission control device for internal combustion engine and control method therefor |
| JP2004197693A (en) * | 2002-12-20 | 2004-07-15 | Nissan Motor Co Ltd | Air/fuel ratio control system of internal combustion engine |
| CN105257419A (en) * | 2015-10-28 | 2016-01-20 | 石家庄益科创新科技有限公司 | Self-learning achieving method of small engine electronic fuel injection system based on narrow area oxygen sensor |
| JP2016223442A (en) * | 2015-06-02 | 2016-12-28 | トヨタ自動車株式会社 | Control device of exhaust emission control system |
| US20160376962A1 (en) * | 2015-06-25 | 2016-12-29 | Hyundai Motor Company | METHOD OF REGENERATING LEAN NOx TRAP OF EXHAUST PURIFICATION SYSTEM PROVIDED WITH LEAN NOx TRAP AND SELECTIVE CATALYTIC REDUCTION CATALYST AND EXHAUST PURIFICATION SYSTEM |
| CN109113883A (en) * | 2017-06-22 | 2019-01-01 | 联合汽车电子有限公司 | The air/fuel ratio control method and device of internal combustion engine |
| CN111075583A (en) * | 2019-12-31 | 2020-04-28 | 潍柴动力股份有限公司 | Closed-loop control method and system for natural gas engine rear oxygen sensor |
| CN112081677A (en) * | 2020-08-28 | 2020-12-15 | 奇瑞汽车股份有限公司 | Air-fuel ratio control method and device |
-
2022
- 2022-03-14 CN CN202210249313.5A patent/CN114856841B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0490612A1 (en) * | 1990-12-10 | 1992-06-17 | Ford Motor Company Limited | Adaptive air/fuel ratio control method and system |
| WO1998055742A1 (en) * | 1997-06-03 | 1998-12-10 | Siemens Aktiengesellschaft | PROCESS FOR REGENERATING AN NOx ACCUMULATOR CATALYTIC CONVERTER |
| JP2001132514A (en) * | 1999-11-01 | 2001-05-15 | Tokyo Gas Co Ltd | Exhaust emission control device for internal combustion engine and control method therefor |
| JP2004197693A (en) * | 2002-12-20 | 2004-07-15 | Nissan Motor Co Ltd | Air/fuel ratio control system of internal combustion engine |
| JP2016223442A (en) * | 2015-06-02 | 2016-12-28 | トヨタ自動車株式会社 | Control device of exhaust emission control system |
| US20160376962A1 (en) * | 2015-06-25 | 2016-12-29 | Hyundai Motor Company | METHOD OF REGENERATING LEAN NOx TRAP OF EXHAUST PURIFICATION SYSTEM PROVIDED WITH LEAN NOx TRAP AND SELECTIVE CATALYTIC REDUCTION CATALYST AND EXHAUST PURIFICATION SYSTEM |
| CN105257419A (en) * | 2015-10-28 | 2016-01-20 | 石家庄益科创新科技有限公司 | Self-learning achieving method of small engine electronic fuel injection system based on narrow area oxygen sensor |
| CN109113883A (en) * | 2017-06-22 | 2019-01-01 | 联合汽车电子有限公司 | The air/fuel ratio control method and device of internal combustion engine |
| CN111075583A (en) * | 2019-12-31 | 2020-04-28 | 潍柴动力股份有限公司 | Closed-loop control method and system for natural gas engine rear oxygen sensor |
| CN112081677A (en) * | 2020-08-28 | 2020-12-15 | 奇瑞汽车股份有限公司 | Air-fuel ratio control method and device |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115788691A (en) * | 2022-11-30 | 2023-03-14 | 东风汽车集团股份有限公司 | Exhaust Gas Recirculation (EGR) rate optimization control method based on passive regeneration of General Purpose Filter (GPF) |
| CN115949524A (en) * | 2022-11-30 | 2023-04-11 | 东风汽车集团股份有限公司 | Exhaust Gas Recirculation (EGR) rate optimization control method based on GPF regeneration |
| CN116201647A (en) * | 2022-11-30 | 2023-06-02 | 东风汽车集团股份有限公司 | EGR rate optimization control method based on GPF active regeneration |
| CN116201647B (en) * | 2022-11-30 | 2024-08-20 | 东风汽车集团股份有限公司 | EGR rate optimization control method based on GPF active regeneration |
| CN115949524B (en) * | 2022-11-30 | 2024-08-20 | 东风汽车集团股份有限公司 | EGR rate optimization control method based on GPF regeneration |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114856841B (en) | 2023-06-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114856841A (en) | GPF regeneration control method based on two-point oxygen sensor | |
| EP1279548B1 (en) | Control system and method for vehicle having continuously variable transmission | |
| US9777659B2 (en) | Control device of internal combustion engine | |
| US7725247B2 (en) | Abnormality diagnostic device and abnormality diagnostic method for air-fuel ratio sensor | |
| KR100680683B1 (en) | Control Device for Internal Combustion Engine | |
| US9255536B2 (en) | Method and device for operating an internal combustion engine | |
| US20060011180A1 (en) | Control system for internal combustion engine | |
| US9027535B2 (en) | Control apparatus for internal combustion engine | |
| US20120197471A1 (en) | Hybrid vehicle | |
| US10006382B2 (en) | Apparatus for detecting inter-cylinder air-fuel ratio imbalance in multi-cylinder internal combustion engine | |
| EP2414659B1 (en) | Controlling exhaust gas recirculation in a combustion engine | |
| US9863343B2 (en) | Method and device for operating an exhaust gas recirculation of a self-ignition internal combustion engine, in particular of a motor vehicle | |
| US6253546B1 (en) | Torque control scheme for low emission lean burn vehicle | |
| WO2019238246A1 (en) | System and method for air/fuel ratio balancing | |
| CN114508430A (en) | Control apparatus for controlling injection amount of hydrogen gas for internal combustion engine | |
| JP2014013032A (en) | Detection device for abnormality of variation in air-fuel ratio between cylinder | |
| EP2093405A1 (en) | Vehicle control method and vehicle control device | |
| CN106351757A (en) | Method for controlling emission during automatic start and stop of vehicle | |
| KR102283605B1 (en) | Method for the detection and description of a transient driving situation | |
| EP3707362B1 (en) | Engine control systems and methods for regulating emissions during scavenging | |
| US9506416B2 (en) | Inter-cylinder air-fuel ratio variation abnormality detection apparatus for multicylinder internal combustion engine | |
| US10215113B2 (en) | Method and device for operating an internal combustion engine | |
| US6530358B2 (en) | Method for controlling an internal combustion engine | |
| KR101808651B1 (en) | Diagnosis method and device for operating an internal combustion engine | |
| JP2015190397A (en) | Internal combustion engine soot emission estimation device |
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 |