CN115992766A

CN115992766A - Engine control method, system, electronic equipment and storage medium

Info

Publication number: CN115992766A
Application number: CN202211528614.8A
Authority: CN
Inventors: 雷雪; 张春娇; 赵田芳; 岳永召
Original assignee: Dongfeng Motor Group Co Ltd
Current assignee: Dongfeng Motor Group Co Ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-04-21

Abstract

The invention discloses an engine control method, an engine control system, electronic equipment and a storage medium, wherein the method comprises the steps of obtaining the current combustion information of an engine; based on the pre-ignition frequency information, determining an EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation, and obtaining a first EGR rate; determining a maximum EGR rate meeting the first preset condition based on knocking information corresponding to the first preset condition to obtain a second EGR rate; determining a maximum EGR rate meeting a second preset condition based on knocking information corresponding to the second preset condition, and obtaining a third EGR rate; determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information to obtain a fourth EGR rate; determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information to obtain a fifth EGR rate; determining a maximum value, and determining a target EGR rate adjustment amount according to the identified maximum value; and controlling the change amount of the throttle valve according to the target EGR rate adjustment amount, and controlling the throttle valve of the engine.

Description

Engine control method, system, electronic equipment and storage medium

Technical Field

The present invention relates to the field of information technologies, and in particular, to an engine control method, an engine control system, an electronic device, and a storage medium.

Background

Currently, EGR systems have certain advantages in improving emissions, reducing fuel consumption, and improving antiknock capabilities. The EGR exhaust gas reduces the combustion temperature, avoids knocking, and suppresses the ignition advance retardation.

However, the inventors have studied and found that when the current engine is under control, there is a tendency that the throttle valve is not controlled properly, resulting in abnormal control of the transmitter.

Disclosure of Invention

An object of an embodiment of the present invention is to provide an engine control method, system, electronic device, and storage medium, capable of determining a target EGR rate adjustment amount according to an identified maximum value; and controlling the throttle valve variation according to the target EGR rate adjustment amount to realize the control of the throttle valve variation of the engine. The specific technical scheme is as follows:

in a first aspect of the embodiment of the present invention, there is provided an engine control method including:

acquiring current combustion information of an engine, wherein the combustion information comprises pre-ignition frequency information, knocking information corresponding to a first preset condition, knocking information corresponding to a second preset condition, ignition angle information and engine speed information;

Based on the pre-ignition frequency information, determining an EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation, and obtaining a first EGR rate; determining the maximum EGR rate meeting the first preset condition based on the knocking information corresponding to the first preset condition to obtain a second EGR rate; determining the maximum EGR rate meeting the second preset condition based on the knocking information corresponding to the second preset condition to obtain a third EGR rate; determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information to obtain a fourth EGR rate; determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information to obtain a fifth EGR rate;

identifying a maximum of the first EGR rate, the second EGR rate, the third EGR rate, the fourth EGR rate, and the fifth EGR rate;

judging whether the maximum value of the EGR rate meets the condition, when the identified maximum value meets the preset condition, determining adjustment gradients of different EGR rates according to the identified maximum value and whether idle closed-loop control is activated or not, and determining the adjustment quantity of the final EGR rate according to the determined adjustment gradients of the EGR rate;

and controlling the change rate of the throttle valve according to the adjustment amount of the final EGR rate, thereby realizing the control of the throttle valve of the engine.

Further, determining whether the EGR rate maximum value satisfies the condition includes:

the engine is pre-ignited or knocked with high intensity; or alternatively, the process may be performed,

the activation condition for decreasing the EGR rate is satisfied within a preset time T0 after the end of the engine pre-combustion or the high-intensity knocking.

Further, the activation condition for reducing the EGR rate satisfies the condition including:

throttle outlet pressure p _Man And inlet pressure p _prethr Ratio of

Is larger than a preset value;

EGR valve outlet pressure p _EGROut And inlet pressure p _EGRIn Ratio of

Is larger than a preset value; />

The engine requested torque exceeds the engine maximum torque capacity multiplied by a preset coefficient K1;

when the three conditions meet that the time is longer than the preset time T1, the activating condition for reducing the EGR rate is met.

Further, the determining, based on the pre-ignition frequency information, the EGR rate corresponding to the pre-ignition frequency information according to a first preset correspondence, to obtain a first EGR rate includes:

and determining an EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation based on the pre-ignition frequency information, the rotating speed of the transmitter, the water temperature of the transmitter and/or the air inlet temperature, and obtaining a first EGR rate.

Further, the determining, based on the knock information corresponding to the first preset condition, the maximum EGR rate satisfying the first preset condition, to obtain the second EGR rate includes:

Determining that: the variation of the retarded ignition angle is not smaller than the difference between the ignition angle before knocking is retarded and the minimum ignition angle, and/or the variation of the retarded ignition angle is not smaller than the maximum EGR rate of the maximum allowable ignition angle variation, resulting in the second EGR rate.

Further, the determining, based on the knock information corresponding to the second preset condition, the maximum EGR rate satisfying the second preset condition, to obtain the third EGR rate includes:

determining that: the variation of the retarded ignition angle is smaller than the difference between the ignition angle before knocking is retarded and the minimum ignition angle, and the variation of the retarded ignition angle is smaller than the maximum EGR rate of the maximum allowable ignition angle variation, resulting in the third EGR rate.

Further, determining, based on the ignition angle information, a corresponding maximum EGR rate according to a second preset correspondence relationship, to obtain a fourth EGR rate, including:

calculating according to the engine speed and the engine water temperature to obtain a first time;

determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information and the first time to obtain a fourth EGR rate;

calculating to obtain second time according to the engine speed and the engine water temperature;

and determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information and the second temperature, and obtaining a fifth EGR rate.

According to a second aspect of the present invention, there is provided an engine control system comprising:

the information acquisition module is used for acquiring current combustion information of the engine, wherein the combustion information comprises pre-ignition frequency information, knocking information corresponding to a first preset condition, knocking information corresponding to a second preset condition, ignition angle information and engine rotating speed information;

the information calculation module is used for determining the EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation based on the pre-ignition frequency information to obtain a first EGR rate; determining the maximum EGR rate meeting the first preset condition based on the knocking information corresponding to the first preset condition to obtain a second EGR rate; determining the maximum EGR rate meeting the second preset condition based on the knocking information corresponding to the second preset condition to obtain a third EGR rate; determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information to obtain a fourth EGR rate; determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information to obtain a fifth EGR rate;

a maximum value determination module that identifies a maximum value of the first EGR rate, the second EGR rate, the third EGR rate, the fourth EGR rate, and the fifth EGR rate;

An adjustment amount determining module for

and the change amount determining module is used for controlling the change rate of the throttle valve according to the adjustment amount of the final EGR rate so as to realize the control of the throttle valve of the engine.

According to a third aspect of the present invention, there is provided an electronic device comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

a memory for storing a computer program;

and the processor is used for realizing the steps of the method when executing the program stored in the memory.

According to a third aspect of the present invention, there is provided a computer readable storage medium having stored therein a computer program which when executed by a processor implements the method steps.

The embodiment of the invention has the beneficial effects that:

the engine control method, the system, the electronic equipment and the storage medium provided by the embodiment of the invention can acquire the current combustion information of the engine, wherein the combustion information comprises pre-ignition frequency information, knocking information corresponding to a first preset condition, knocking information corresponding to a second preset condition, ignition angle information and engine speed information; based on the pre-ignition frequency information, determining an EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation, and obtaining a first EGR rate; determining the maximum EGR rate meeting the first preset condition based on the knocking information corresponding to the first preset condition to obtain a second EGR rate; determining the maximum EGR rate meeting the second preset condition based on the knocking information corresponding to the second preset condition to obtain a third EGR rate; determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information to obtain a fourth EGR rate; determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information to obtain a fifth EGR rate; identifying a maximum of the first EGR rate, the second EGR rate, the third EGR rate, the fourth EGR rate, and the fifth EGR rate; when the identified maximum value meets a preset condition, determining a target EGR rate adjustment amount according to the identified maximum value; and controlling the throttle valve variation according to the target EGR rate adjustment. It can be seen that, by the method of the embodiment of the present invention, the target EGR rate adjustment amount can be determined according to the identified maximum value; and controlling the throttle valve variation according to the target EGR rate adjustment amount, thereby realizing the control of the engine throttle valve.

Of course, it is not necessary for any one product or method of practicing the invention to achieve all of the advantages set forth above at the same time.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the invention, and other embodiments may be obtained according to these drawings to those skilled in the art.

FIG. 1 is a schematic flow chart of an engine control method according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating an example of an engine control method according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an engine control device according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by the person skilled in the art based on the present invention are included in the scope of protection of the present invention.

In a first aspect of the embodiment of the present invention, there is provided an engine control method, referring to fig. 1, including:

step S11, current combustion information of an engine is obtained, wherein the combustion information comprises pre-ignition frequency information, knocking information corresponding to a first preset condition, knocking information corresponding to a second preset condition, ignition angle information and engine rotating speed information;

step S12, determining an EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation based on the pre-ignition frequency information, and obtaining a first EGR rate; determining a maximum EGR rate meeting the first preset condition based on knocking information corresponding to the first preset condition to obtain a second EGR rate; determining a maximum EGR rate meeting a second preset condition based on knocking information corresponding to the second preset condition, and obtaining a third EGR rate; determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information to obtain a fourth EGR rate; determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information to obtain a fifth EGR rate;

step S13 of identifying a maximum value among the first EGR rate, the second EGR rate, the third EGR rate, the fourth EGR rate, and the fifth EGR rate;

And S14, when the identified maximum value meets a preset condition, determining a target EGR rate adjustment amount according to the identified maximum value.

Step S15, controlling the throttle valve change amount according to the target EGR rate adjustment amount.

In the prior art, the ignition angles comprise an MBT ignition angle, a basic ignition angle and a minimum ignition angle, different ignition angles correspond to different ignition efficiencies, and 1, wherein the ignition efficiency corresponding to the MBT ignition angle is 1;2, the basic ignition angle is a basic ignition angle determined under the condition of avoiding knocking under the MBT ignition angle and considering the combustion efficiency of the engine, the ignition efficiency corresponding to the basic ignition angle is smaller than 1, and the basic ignition angle minus the ignition angle of knocking delay can be determined as a final allowable ignition angle; 3, the minimum firing angle means: the minimum ignition angle that the engine is allowed to reach is set to be the minimum ignition angle within the range of the engine exhaust temperature protection requirement and the range of the engine combustion stability allowance. The minimum firing angle corresponds to a firing efficiency that is not greater than the firing efficiency corresponding to the base firing angle.

In the prior art, when the EGR rate is not properly introduced, knocking and pre-combustion can be influenced instead when the EGR rate is too small, and the EGR rate can be increased to avoid knocking and pre-combustion.

In the embodiment of the invention, under the normal working condition, the combustion stability of the engine corresponding to the maximum EGR rate is higher than the combustion stability requirement of the engine under the abnormal working condition. However, in some abnormal working conditions, in order to protect the engine, the EGR rate is properly increased, the combustion stability requirement is reduced, and the combustion stability COV IMEP of the embodiment under the abnormal working conditions is less than 2.5%; the combustion stability COV IMEP under abnormal conditions is less than 3%.

In the embodiment of the invention, under the default working condition, the default maximum EGR rate under the working condition without abnormality is r _{EGRMaxDefault} The following conditions are abnormal conditions: the occurrence of pre-ignition; knocking occurs and is serious; knocking does not occur seriously, but the base firing angle is very close to the minimum firing angle; knocking does not occur, but the base firing angle is very close to the minimum firing angle; knocking does not occur, the base firing angle is not close to the minimum firing angle, butIs the fluctuation abnormality of the actual rotation speed and the target rotation speed of the engine.

Finally, the maximum EGR rate to be determined based on pre-ignition is r _{EGRMaxForPreIgnitionFinal} The maximum EGR rate determined based on high-intensity knock is r _{EGRMaixgFhoKrnnHoa} The maximum EGR rate determined based on knock is r _{EGRMaoxftFKornoSa} The maximum EGR rate determined based on the ignition angle is r _{EGRMaxFoSparkAngleFnial} And a maximum EGR rate r determined based on the rotational speed fluctuation _{EGRMaxFoEngineSpeedDiffFinal} The maximum value is taken as the maximum EGR rate under the final engine protection.

Referring to fig. 2, by the method of the embodiment of the present invention, the maximum EGR rate at which pre-ignition occurs may be calculated, the maximum EGR rate at which high-intensity knocking occurs may be calculated, the maximum EGR rate at which non-high-intensity knocking occurs may be calculated, the maximum EGR rate at which ignition angle exhaust temperature is over-limited, the maximum EGR rate at abnormal fluctuation of rotational speed may be calculated, and the final maximum EGR rate may be determined.

The method can realize graded regulation and control under the conditions of pre-combustion, high-intensity knocking, non-high-intensity knocking, limited ignition angle and abnormal fluctuation of rotating speed, simultaneously avoid the influence on combustion stability and torque response precision, design the maximum EGR rate, protect the engine and ensure the use advantage of the EGR rate as much as possible.

It can be seen that, by the method according to the embodiment of the present invention, the target EGR rate adjustment amount may be determined according to the identified maximum value; and controlling the throttle valve variation according to the target EGR rate adjustment amount, thereby realizing the control of the engine throttle valve.

In one possible embodiment, when the identified maximum value satisfies a preset condition, determining the target EGR rate adjustment amount according to the identified maximum value includes: when the identified maximum value meets a preset condition, determining an EGR rate adjustment gradient according to the identified maximum value; and determining a target EGR rate adjustment amount according to the determined EGR rate adjustment gradient.

In one example, the method for controlling the real-time target EGR rate based on knocking or pre-combustion under the actual EGR rate comprises: an activation condition judgment for increasing the EGR rate; after the activation condition for increasing the EGR rate is met, determining an adjustment gradient grade of the EGR rate according to the idle speed closed-loop flag bit of the engine; after the activation condition for increasing the EGR rate is satisfied, the throttle opening degree change rate is limited.

(1) And (3) judging the activation condition for increasing the EGR rate. Engine combustion stability COV IMEP less than 3%; a) Once the pre-combustion or the high-intensity knocking occurs, b) the activation condition for decreasing the EGR rate is satisfied within a preset time T0 (taking 0.1s in this example) after the end of the pre-combustion or the high-intensity knocking. High intensity knock refers to: the amount of change in the ignition angle that knocking needs to be retarded is not less than the difference between the ignition angle before knocking is retarded and the minimum ignition angle; when knocking occurs, the variation amount of the ignition angle of knocking delay reaches the allowable maximum variation amount of the ignition angle of knocking delay (the allowable maximum variation amount of knocking occurrence cannot be too small, otherwise the risk of further occurrence of knocking is caused;

At throttle outlet pressure p _Man And inlet pressure p _prethr Ratio of

Greater than a preset value, this example takes 0.987; simultaneous EGR valve outlet pressure p _EGROut And inlet pressure p _EGRIn Ratio->

Greater than a preset value, this example takes 0.975; while the engine torque request exceeds the engine torque capacity multiplied by a preset coefficient K1. When the three conditions are satisfied for a time longer than the preset time T1, the activation condition for reducing the EGR rate is satisfied, and the activation condition for reducing the EGR rate at least satisfies for a time longer than T2 (even if the three conditions are satisfied for a short time from satisfaction to non-satisfaction, the example takes 1.5 s). T1 is 0.18s, the preset coefficient K1 and the engine speed n are adopted, and fresh air density rho and ignition efficiency r of an entering cylinder are obtained _SparkEff In relation, k1=f ₁ (n,rho)×f ₁ (n,r _SparkEff ) The lower the ignition efficiency at the same engine speed and fresh air density entering the cylinder, the failure to achieve in time in knocking occurrence is achieved by adjusting the ignition angle, which may cause deterioration of the exhaust temperature or combustion stability. The smaller the ignition efficiency is, the smaller the preset coefficient K1 is to suppress the risk of knocking or excessive exhaust temperature. Firstly, different engine speeds and fresh air density entering a cylinder on a rack are calibrated to preset coefficients for the purpose of suppressing knocking when the ignition efficiency is 1, and secondly, the calibration preset coefficients for the purpose of suppressing knocking and avoiding excessive exhaust temperature are adjusted under different ignition efficiencies.

Table 1 correspondence table of engine speed and air density

Table 2 correspondence table of engine speed and ignition efficiency

Wherein, the basis of T1 and K1 is: the occurrence of knocking and the combustion stability COV IMEP are avoided to be not less than 3%.

(2) And after the activation condition of increasing the EGR rate is met, determining an adjustment gradient grade of increasing the EGR rate according to whether the idle closed loop of the engine is activated or not. After the activation condition for increasing the EGR rate is satisfied, the EGR rate is adjusted regardless of whether the vehicle is in the idle closed loop. However, when the engine is in the idle closed loop, the engine combustion stability condition capability is large, and the EGR rate increase adjustment range is not large in the non-idle closed loop. When the activation condition for increasing the EGR rate is not satisfied, the EGR rate immediately returns to the original unadjusted EGR rate. When the engine is in idle closed loop, the EGR rate variation is adjusted to the gradient corresponding to Table 3; the EGR rate variation was adjusted to the gradient corresponding to table 4 when the engine was in a non-idle closed loop.

TABLE 3 variation in EGR Rate

TABLE 4 variation in EGR Rate

The calibration basis of the gradient I and the gradient II is that the combustion stability COV IMEP is less than 3 percent, and the torque response precision is not lower than +/-5 percent.

When switching between the two gradients (i.e., from idle closed loop to non-idle closed loop, or from non-idle closed loop to idle closed loop), the absolute value of the rate of change of the EGR rate variation is determined by both the engine speed and the engine water temperature. That is, the change rate takes the table value when the change amount increases, and takes the negative value of table 5 when the change amount decreases.

Table 5 a table of engine speed and intake air temperature

The calibration is based on no knocking occurring when switching from idle to non-idle or from non-idle to idle, torque response accuracy is not less than + -5% and combustion stability COV IMEP <3%. The final EGR rate after adjustment can be obtained by subtracting the adjusted EGR rate variation from the original unadjusted EGR rate. After the time for increasing the EGR rate exceeds the time T4 each time, the adjustment of the EGR rate is allowed to be increased again after the time T3 is delayed at least, so that the influence on the power torque precision is avoided. Wherein T3 takes 0.5s, and the time of T4 depends on the engine speed and the water temperature, see Table 6.

TABLE 6 Another engine speed and intake air temperature mapping

/>

After the activation condition for increasing the EGR rate is satisfied, the throttle opening rate is limited, and the throttle opening is retarded to reduce the fluctuation rate of the intake air, so that the influence on the combustion stability of the engine during EGR adjustment is avoided. The throttle opening rate correction multiplier is determined in dependence on the engine speed and the intake air charge density of the intake cylinder, and is also such that combustion stability COV IMEP <3% is ensured. The throttle opening degree change rate correction multiplication factor is multiplied by the original throttle opening degree change rate to determine the throttle opening degree change rate at the time of increasing the EGR rate activation. After the activation condition for increasing the EGR rate is not satisfied, the throttle opening change rate is gradually restored (the change rate is 2%/s) to the original throttle opening change rate, specifically, see tables 7 and 8.

TABLE 7 Engine speed and charge density mapping table

Table 8 another engine speed and charge density mapping table

In one possible embodiment, determining, based on the pre-ignition count information, an EGR rate corresponding to the pre-ignition count information according to a first preset correspondence, to obtain a first EGR rate includes: and determining the EGR rate corresponding to the pre-ignition frequency information through a first preset corresponding relation based on the pre-ignition frequency information, the rotating speed of the transmitter, the water temperature of the transmitter and/or the air inlet temperature, and obtaining a first EGR rate.

Specifically, the maximum EGR rate determined based on pre-ignition is determined to be r _{EGRMaxForPreIgnitionFinal} 。

The engine pre-ignition frequency counter accumulates the pre-ignition frequency from 0, and displays 1 time of occurrence in the accumulated pre-ignition frequency of the engine, and sets the maximum EGR rate limit value r _{EGRMaxForPreIgnitioneLvel1} (n, rho), which is determined by both the engine speed n and the intake cylinder fresh air charge density rho;

setting maximum EGR rate limit r for 1 occurrence in cumulative display of number of pre-combustions _{EGRMaxForPreIgnitioenvLel1} (n, rho) time exceeds a period of time T _Level1 The post-reduction pre-ignition frequency counter is 0, and the default maximum EGR rate is r under the no-abnormal working condition _{EGRMaxDefault} The value T _Level1 Can be based on the engine speed n and the engine water temperature T _Coolant Determining together;

when the engine pre-ignition count counter is 1, if the engine pre-ignition occurs again, the updated pre-ignition count is accumulated to 2 times, and the maximum EGR rate limit r is set _{EGRMaxForPreIgnitionLevel2} (n, rho), which is determined by both the engine speed n and the intake cylinder fresh air charge density rho; when the number of times of engine pre-combustion is N (more than 2), if pre-combustion occurs again, the number of times of updating pre-combustion is accumulated to N times, and a target air quantity limit value r is set _{EGRMaxForPreIgnitionLevel2} (n, rho), which is determined by both the engine speed n and the intake cylinder fresh air charge density rho;

setting the maximum EGR rate limit r at 2 or more occurrences of cumulative pre-ignition times _{EGRMaxForPreIgnietivoe2} (lnn, lrho) time exceeds a period of time T _Level2 And then the number of times of pre-ignition is reduced to N-1. If N-1 is greater than or equal to 2, maintaining the maximum EGR rate limit r _{EGRMaxForPreIgnitionLevel2} (n, rho); if N-1=1, the maximum EGR rate limit is adjusted to r _{EGRMaxForPreIgnitionLevel1} (n, rho). The value T _Level2 Can be started according toEngine speed n and engine water temperature T _Coolant Together, the higher the water temperature, the greater the risk of pre-ignition;

maximum EGR rate limit r at which final pre-ignition occurs _{EGRMaxForPreIgnition} Will limit its maximum rate of change, which is dependent on the engine speed n, and from there, the final maximum EGR rate limit r based on the occurrence of pre-ignition _{EGRMaxForPreIgnitioinaFl} All determinations. The determination method of the above calibration data is set based on avoiding occurrence of pre-ignition while avoiding an increase in EGR rate that would result in an engine combustion stability COV IMEP of not less than 3% and poor torque responsiveness (torque response accuracy of not less than ±5%).

The EGR rate is limited to various degrees depending on the number of times (severity) that the engine pre-combustion occurs, so that further occurrence of pre-combustion can be suppressed and the power performance of the engine can be maintained as much as possible.

In one possible embodiment, determining the maximum EGR rate satisfying the first preset condition based on knock information corresponding to the first preset condition, to obtain the second EGR rate includes: determining that: the variation of the retarded ignition angle is not smaller than the difference between the ignition angle before knocking is retarded and the minimum ignition angle, and/or the variation of the retarded ignition angle is not smaller than the maximum EGR rate of the maximum allowable ignition angle variation, resulting in the second EGR rate.

Specifically, the maximum EGR rate determined based on high-intensity knock is r _{EGRMaxForiHghKnockFnial} 。

When knocking occurs, and the amount of change in the ignition angle that knocking needs to be retarded is not less than the difference between the ignition angle before knocking is retarded and the minimum ignition angle; when the variation amount of the ignition angle of knocking delay reaches the allowable maximum variation amount of the ignition angle of knocking delay (the allowable maximum variation amount of knocking generation cannot be too small, otherwise the risk of further occurrence of knocking is caused, and the dynamic property of the engine is influenced by the same cannot be too large, the allowable maximum variation amount of the ignition angle of knocking delay is set to be 10 DEG), at least one of two conditions is met, and the engine knocks with high intensity. To further suppress knocking, reduce engine knocking, a maximum EGR rate limit r is set _{EGRMaxForiHghKnock} (n, rho) time exceedsFor a period of time T _HighKnock The default maximum EGR rate after recovery to no abnormal condition is r _{EGRMaxDefault} The value T _HighKnock Can be based on the engine speed n and the engine water temperature T _Coolant And (5) jointly determining.

Maximum EGR rate limit r at which final high-intensity knock occurs _{EGRMaxForiHghKnock} The maximum rate of change thereof is limited, which depends on the engine speed n, and thus the final maximum EGR rate limit r based on the occurrence of high-intensity knocking _{EGRMaxForiHghKnockFnial} All determinations. The determination method of the above calibration data is set based on avoiding occurrence of high-intensity knocking while avoiding an increase in EGR rate that is excessive and results in engine combustion stability COV IMEP of not less than 3% and poor torque responsiveness (torque response accuracy of not less than ±5%).

In one possible embodiment, determining the maximum EGR rate satisfying the second preset condition based on knock information corresponding to the second preset condition, to obtain the third EGR rate includes: determining that: the variation of the retarded ignition angle is smaller than the difference between the ignition angle before knocking is retarded and the minimum ignition angle, and the variation of the retarded ignition angle is smaller than the maximum EGR rate of the maximum allowable ignition angle variation, resulting in the second EGR rate.

Specifically, the maximum EGR rate determined based on knock is r _{EGRMaxForoSftKnockFnial}

1) If knocking occurs, but the amount of change in the ignition angle of knocking retardation is smaller than that before knocking retardation

The difference between the angle and the minimum firing angle, and the amount of change in the firing angle of knock retardation does not reach the amount of change in the maximum firing angle of knock retardation, indicates that the engine does not knock at high intensity.

2) Meanwhile, the difference between the current basic firing angle and the minimum firing angle is smaller than the preset angle C1, which is taken as 3 ° in this example. It is explained that if the EGR rate is set too large, there is a possibility that further knocking will occur, but at this time the adjustment of the ignition angle is too small, and the occurrence of knocking may not be avoided in time.

When the above conditions are satisfied, in order to further suppress knocking and reduce the possibility of engine knocking, a maximum EGR rate limit value r is set _{EGRMaxForoSftKnock} (n, rho) time exceeds a period of time T _SoftKnock The default maximum EGR rate after recovery to no abnormal condition is r _{EGRMaxDefault} The value T _SoftKnock Can be based on the engine speed n and the engine water temperature T _Coolant And (5) jointly determining. Equal engine speed and intake cylinder freshness r _{EGRMaxForoSftKnock} (n, rho) is not greater than a maximum EGR rate limit r determined based on high-intensity knock occurrence _{EGRMaxForiHghKnock} (n, rho), also T _SoftKnock Not greater than T _HighKnock 。

Maximum EGR rate limit r at the time of final knocking occurrence _{EGRMaxForoSftKnock} The maximum rate of change thereof is limited, which depends on the engine speed n, and thus the final maximum EGR rate limit r based on the occurrence of knocking _{EGRMaxFoofrtSKnocnkaFli} All determinations. The determination method of the above calibration data is set based on avoiding occurrence of knocking while avoiding an increase in EGR rate that would cause an engine combustion stability COV IMEP of not less than 3% and poor torque responsiveness (torque response accuracy of not less than ±5%).

In one possible embodiment, determining the corresponding maximum EGR rate according to the second preset correspondence based on the ignition angle information, to obtain the fourth EGR rate includes: calculating according to the engine speed and the engine water temperature to obtain a first time; and determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information and the first time, so as to obtain a fourth EGR rate.

Specifically, the maximum EGR rate determined based on the firing angle is r _{EGRMaxFoSparkAngleFnial}

The current knocking does not occur, but the difference between the basic ignition angle and the minimum ignition angle is smaller than a preset angle C2 (C2 is not larger than C1, 1.2 ° is taken in this example), and the post-throttle target intake pressure change rate Δmap _Dsrd Exceeding a preset value (4000 kPa/s in this example). The engine load is illustrated as increasing, but the margin by which the ignition angle is adjustable is too small, which may cause a risk of knocking if the EGR rate is set too small.

Setting a maximum EGR rate limit

The time exceeds a preset time T _SparkAngle The default maximum EGR rate after recovery to no abnormal condition is r _{EGRMaxDefault} A value T of the preset time _SparkAngle Can be based on the engine speed n and the engine water temperature T _Coolant And (5) jointly determining. Wherein phi is _Base Phi is the current real-time basic firing angle _Min Phi is the current real-time minimum firing angle _Margin For the angle margin of the difference between the basic firing angle and the minimum firing angle, the present example takes 3.5 °. At->

Less than 1, and the smaller the value or ΔMAP _Dsrd The greater the +.>

The larger the knock occurrence is further suppressed.

EGR rate limit at final knock occurrence

Will limit its rate of change, which is dependent on the engine speed n, and hence the final ignition angle based EGR rate limit r _{EGRMaxFoSparkAngleFnial} All determinations. The determination method of the above calibration data is set based on avoiding occurrence of knocking and excessive exhaust temperature risk, while avoiding excessive increase of EGR rate to cause engine combustion stability COV IMEP not less than 3% and poor torque responsiveness (torque response accuracy not less than ±5%).

In one possible embodiment, determining the corresponding maximum EGR rate through the third preset correspondence based on the engine speed information, to obtain the fifth EGR rate includes: calculating to obtain second time according to the engine speed and the engine water temperature; and determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information and the second temperature, so as to obtain a fifth EGR rate.

Specifically, the maximum EGR rate determined based on the rotational speed fluctuation is r _{EGRMaxFoEngineSpeedDiffFinal} In the rotating speed closed loop control processUnder the condition that the current knocking does not occur, the difference between the basic ignition angle and the minimum ignition angle is not smaller than a preset angle C2 (C2 is not larger than C1, 1.2 degrees is taken in the example), and the target air inlet pressure change rate delta MAP after the throttle valve _Dsrd Does not exceed a preset value (4000 kPa/s in this example), but the absolute value n of the difference between the target rotational speed and the actual rotational speed of the engine _EngSpeedDfif Above the preset value, the present example takes (50 rpm) and maintains time T1 for more than 1.2s. Indicating that the fluctuation of the rotating speed is large, limiting the maximum EGR rate limit value r if the EGR rate is set to be too large and possibly causing the risk of aggravating the fluctuation of the rotating speed _{EGRMaxFoEngineSpeedDiff} (n,rho)×k(n，n _EngSpeedDfif ) For more than a period of time T _SparkAngle The default maximum EGR rate after recovery to no abnormal condition is r _{EGRMaxDefault} The value T _SparkAngle Can be based on the engine speed n and the engine water temperature T _Coolant And (5) jointly determining. The smaller the engine speed n is and the absolute value n of the difference between the speeds _EngSpeedDfif The greater k (n, n _EngSpeedDfif ) The smaller the rotation speed fluctuation is improved.

Maximum EGR rate limit r when final speed fluctuation occurs _{EGRMaxFoEngineSpeedDiff} (n,rho)×k(n，n _EngSpeedDfif ) The maximum rate of change is limited, which depends on the engine speed n, and hence the final maximum EGR rate limit r based on speed fluctuations _{EGRMaxFoEngineSpeedDiffFinal} All determinations. The above determination method of the calibration data is set based on the action advantage of avoiding the occurrence of the fluctuation of the rotation speed exceeding the accuracy requirement (20 rpm in this example) due to the EGR rate while avoiding the influence of the excessive decrease of the EGR rate as much as possible.

In a second aspect of the embodiment of the present invention, there is provided an engine control apparatus, referring to fig. 3, including:

an information obtaining module 301, configured to obtain current combustion information of an engine, where the combustion information includes pre-ignition frequency information, knock information corresponding to a first preset condition, knock information corresponding to a second preset condition, ignition angle information, and engine rotation speed information;

the information calculation module 302 is configured to determine, based on the pre-ignition frequency information, an EGR rate corresponding to the pre-ignition frequency information according to a first preset correspondence, so as to obtain a first EGR rate; determining the maximum EGR rate meeting the first preset condition based on the knocking information corresponding to the first preset condition to obtain a second EGR rate; determining the maximum EGR rate meeting the second preset condition based on the knocking information corresponding to the second preset condition to obtain a third EGR rate; determining a corresponding maximum EGR rate through a second preset corresponding relation based on the ignition angle information to obtain a fourth EGR rate; determining a corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information to obtain a fifth EGR rate;

a maximum determination module 303 for identifying a maximum of the first EGR rate, the second EGR rate, the third EGR rate, the fourth EGR rate, and the fifth EGR rate;

An adjustment amount determining module 304, configured to determine a target EGR rate adjustment amount according to the identified maximum value when the identified maximum value satisfies a preset condition;

the change amount determination module 305 is configured to control a throttle valve change amount according to the target EGR rate adjustment amount.

In one possible implementation manner, the adjustment amount determining module is specifically configured to determine an EGR rate adjustment gradient according to the identified maximum value when the identified maximum value meets a preset condition; and determining a target EGR rate adjustment amount according to the determined EGR rate adjustment gradient.

In a possible implementation manner, the information calculating module is specifically configured to determine, based on the pre-ignition frequency information and the transmitter rotation speed, the transmitter water temperature and/or the intake air temperature, an EGR rate corresponding to the pre-ignition frequency information through a first preset correspondence, so as to obtain a first EGR rate.

In a possible implementation manner, the information calculating module is specifically configured to determine that the following is satisfied: the variation of the retarded ignition angle is not smaller than the difference between the ignition angle before knocking is retarded and the minimum ignition angle, and/or the variation of the retarded ignition angle is not smaller than the maximum EGR rate of the maximum allowable ignition angle variation, resulting in the second EGR rate.

In a possible implementation manner, the information calculating module is specifically configured to determine that the following is satisfied: the variation of the retarded ignition angle is smaller than the difference between the ignition angle before knocking is retarded and the minimum ignition angle, and the variation of the retarded ignition angle is smaller than the maximum EGR rate of the maximum allowable ignition angle variation, resulting in the second EGR rate.

In one possible implementation manner, the information calculating module includes:

the first time calculation sub-module is used for calculating to obtain first time according to the engine rotating speed and the engine water temperature;

and the preset relation determining submodule is used for determining the corresponding maximum EGR rate through the second preset corresponding relation based on the ignition angle information and the first time to obtain a fourth EGR rate.

the second time calculation sub-module is used for calculating a second time according to the engine speed and the engine water temperature;

and the preset relation determining sub-module is used for determining the corresponding maximum EGR rate through a third preset corresponding relation based on the engine speed information and the second temperature to obtain a fifth EGR rate.

Therefore, by the device provided by the embodiment of the invention, the target EGR rate can be calculated and determined, and when the current EGR rate is larger than the target EGR rate, the protection action is executed, so that the protection action of the engine is realized.

The embodiment of the invention also provides an electronic device, as shown in fig. 4, which comprises a processor 401, a communication interface 402, a memory 403 and a communication bus 404, wherein the processor 401, the communication interface 402 and the memory 403 complete communication with each other through the communication bus 404,

a memory 403 for storing a computer program;

the processor 401, when executing the program stored in the memory 403, implements the following steps:

when the identified maximum value meets a preset condition, determining a target EGR rate adjustment amount according to the identified maximum value;

and controlling the throttle valve variation according to the target EGR rate adjustment.

The communication bus mentioned above for the electronic devices may be a peripheral component interconnect standard (Peripheral Component Interconnect, PCI) bus or an extended industry standard architecture (Extended Industry Standard Architecture, EISA) bus, etc. The communication bus may be classified as an address bus, a data bus, a control bus, or the like. For ease of illustration, the figures are shown with only one bold line, but not with only one bus or one type of bus.

The communication interface is used for communication between the electronic device and other devices.

The Memory may include random access Memory (Random Access Memory, RAM) or may include Non-Volatile Memory (NVM), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the aforementioned processor.

The processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

In yet another embodiment of the present invention, there is also provided a computer-readable storage medium having stored therein a computer program which, when executed by a processor, implements the steps of any of the engine control methods described above.

In yet another embodiment of the present invention, there is also provided a computer program product containing instructions that, when run on a computer, cause the computer to perform any of the engine control methods of the above embodiments.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present invention, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), etc.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In this specification, each embodiment is described in a related manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for apparatus, electronic devices, storage media, and computer program product embodiments, the description is relatively simple, as it is substantially similar to method embodiments, with reference to the description of method embodiments in part.

The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An engine control method, characterized by comprising:

2. The method of claim 1, wherein determining whether the EGR rate maximum value satisfies a condition comprises:

3. The method of claim 2, wherein the reducing EGR rate activation condition is satisfied comprising:

throttle outlet pressure p _Man And inlet pressure p _prethr Ratio of

Is larger than a preset value;

EGR valve outlet pressure p _EGROut And inlet pressure p _EGRIn Ratio of

Is larger than a preset value;

4. The method according to any one of claims 1-3, wherein determining, based on the pre-ignition count information, an EGR rate corresponding to the pre-ignition count information through a first preset correspondence relationship, to obtain a first EGR rate, includes:

5. A method according to any one of claims 1-3, wherein said determining a maximum EGR rate that satisfies a first preset condition based on said knock information corresponding to said first preset condition, resulting in a second EGR rate, comprises:

6. A method according to any one of claims 1-3, wherein said determining a maximum EGR rate satisfying a second preset condition based on knock information corresponding to the second preset condition, resulting in a third EGR rate, comprises:

7. A method according to any one of claims 1-3, wherein said determining a corresponding maximum EGR rate by a second preset correspondence based on said firing angle information, resulting in a fourth EGR rate, comprises:

8. An engine control system, comprising:

an adjustment amount determining module for

9. The electronic equipment is characterized by comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

a memory for storing a computer program;

a processor for carrying out the method steps of any one of claims 1-7 when executing a program stored on a memory.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored therein a computer program which, when executed by a processor, implements the method steps of any of claims 1-7.