Engine system shutdown delay determination method, engine system shutdown delay control method, engine system shutdown delay control system and vehicle

Abstract

The invention provides an engine system shutdown delay determination method which comprises the following steps: in response to an engine shutdown request instruction, acquiring an actual EGR rate value before shutdown and an exhaust gas length ratio of a first pipeline before shutdown; according to the actual EGR rate value before shutdown, the exhaust gas length ratio before shutdown and the actual vehicle pressurization closed-loop delay database, the basic delay duration of exhausting all exhaust gas in the first pipeline from the throttle valve when the engine system is in the pressurization closed-loop working state is obtained; according to the basic delay duration, determining the duration of exhausting all waste gas in the first pipeline from the throttle valve when the engine system is in a fuel cut-off state and the motor drives the engine to rotate, and taking the duration as a first delay duration; the flowing duration of gas in the engine system flowing from a throttle valve to an exhaust port of an engine air cylinder is obtained and serves as second delay duration; and the first delay duration and the second delay duration are summed, and the shutdown delay duration of the engine system in the fuel cut-off state and the state that the motor drives the engine to rotate is obtained.

Description

Technical Field

[0001] This disclosure relates to the field of engine system control technology, and in particular to a method, control method and system for determining engine system shutdown delay, vehicle, electronic equipment and computer-readable medium. Background Technology

[0002] Hybrid engines are the mainstream type of engine on the market, and EGR technology is a key technology for high thermal efficiency. Hybrid engines have a high frequency of start-stop during vehicle operation. When the engine requests to stop, if there is residual exhaust gas in the engine intake system and cylinders, and the engine requests to start again after stopping, the unpredictable amount of exhaust gas may deteriorate the control stability of the engine starting due to the exhaust gas, which may cause abnormal vibration or even failure to start. Summary of the Invention

[0003] This disclosure aims to at least solve one of the technical problems existing in the prior art, and proposes an engine system shutdown delay determination method, control method and system, vehicle, electronic equipment and computer-readable medium. By extending the shutdown after receiving the engine shutdown request command, the residual exhaust gas in the intake system and cylinder is discharged, thereby reducing the impact of exhaust gas on the starting stability of the engine restart process.

[0004] In a first aspect, this disclosure provides a method for determining engine system shutdown delay, comprising:

[0005] In response to the engine shutdown request command, the actual EGR rate of the current engine system is obtained as the actual EGR rate value before shutdown, and the exhaust gas length ratio in the first pipeline from the EGR valve to the throttle valve in the current engine system is obtained as the exhaust gas length ratio value before shutdown.

[0006] Based on the actual EGR rate value before shutdown, the exhaust gas length ratio value before shutdown, and the pre-acquired real-vehicle turbocharged closed-loop delay database, the time required for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve under turbocharged closed-loop operation is obtained as the basic delay time; wherein, the real-vehicle turbocharged closed-loop delay database records the reference time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve under turbocharged closed-loop operation with multiple different EGR rate values ​​when the first pipeline corresponds to multiple different exhaust gas length ratio values ​​respectively;

[0007] Based on the aforementioned basic delay duration, the duration during which the engine system, in a state of fuel cut-off and engine rotation driven by the motor, discharges all the exhaust gas in the first pipeline from the throttle valve is determined, and this duration is taken as the first delay duration.

[0008] The flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder is obtained as the second delay time;

[0009] The first delay duration and the second delay duration are summed to obtain the shutdown delay duration of the engine system when the fuel is cut off and the engine is driven to rotate by the motor.

[0010] In some embodiments, the step of determining the duration for which the engine system, in a state of fuel cut-off and engine rotation driven by an electric motor, discharges all exhaust gas in the first pipeline from the throttle valve, as the first delay duration, includes:

[0011] It is determined whether the engine system is in a boost closed-loop operating state or not in a boost closed-loop operating state when the engine stop request command is received;

[0012] When it is determined that the engine system is in a boost closed-loop operating state when the engine stop request command is received, the first delay duration is determined based on the following formula:

[0013]

[0014] in, The first delay duration, The base delay duration, The preset delay factor is used. ∈(1,1.2];

[0015] If it is determined that the engine system was not in the boost closed-loop operating state when the engine stop request command was received, then the engine speed at the time the engine stop request command was received is obtained. Engine coolant temperature Atmospheric pressure Throttle inlet pressure Throttle outlet pressure The first delay duration is determined based on the following formula:

[0016]

[0017] in, To determine the throttle body inlet and outlet pressure ratio and engine speed The first adjustment coefficient is obtained by looking up the correspondence between the two parameters and the first preset calibration table. To determine based on engine coolant temperature Atmospheric pressure The second adjustment coefficient is obtained by looking up the second preset calibration correspondence table.

[0018] The first preset calibration correspondence table records multiple different combinations of throttle inlet and outlet pressure ratios and engine speeds, as well as their corresponding adjustment coefficients;

[0019] The second preset calibration correspondence table records multiple different combinations of engine water temperature and atmospheric pressure and their corresponding adjustment coefficients.

[0020] In some embodiments, the method further includes: obtaining a real-vehicle booster closed-loop delay database, specifically including:

[0021] A test result database is obtained, which records the test duration of the engine system operating under the boost closed-loop working state, with the EGR valve closed and the mixing valve fully open, using an engine bench test system to simulate and test the first pipeline under various preset exhaust gas length ratios, and the engine system operating under the boost closed-loop working state using the initial EGR rate values ​​corresponding to various preset categories of EGR rates to discharge all exhaust gas from the first pipeline from the throttle valve.

[0022] During actual vehicle operation, the values ​​of various preset categories of EGR rates of the engine system are acquired in real time according to preset sampling rules. The test result database is updated according to the values ​​of various different EGR rates acquired at each sampling time to obtain the actual vehicle boosting closed-loop delay database.

[0023] In some embodiments, during actual vehicle operation, the steps of acquiring the values ​​of various preset categories of EGR rates of the engine system in real time according to preset sampling rules, and updating the test result database according to the values ​​of various different EGR rates acquired at each sampling time to obtain the actual vehicle boosting closed-loop delay database include:

[0024] Based on the corresponding initial EGR rate values ​​in ascending order, all the preset category EGR rates are sorted to obtain a preset category EGR rate sorting sequence. An EGR rate value array corresponding to the preset category EGR rate sorting sequence is then initialized. The EGR rate value array records the reference values ​​corresponding to each preset category EGR rate according to the preset category EGR rate sorting sequence. When the EGR rate value array is initialized, the reference values ​​corresponding to each preset category EGR rate are the corresponding initial EGR rate values.

[0025] Based on the test result database, multiple delay duration arrays are initialized and generated, each corresponding to a different preset exhaust gas length ratio. Each delay duration array records the reference duration for which the engine system, under the corresponding preset exhaust gas length ratio, uses the reference value of each preset category EGR rate to delay operation in order to discharge all exhaust gas in the first pipeline from the throttle valve. The delay duration array also records the reference duration corresponding to each preset category EGR rate in a sorted sequence according to the preset category EGR rate. When initializing the delay duration array, the reference duration corresponding to each preset category EGR rate is the corresponding test duration recorded in the test result database.

[0026] During actual vehicle operation, in response to the arrival of the acquisition time, the current value of each preset category EGR rate at the corresponding time is obtained, and the current value of each preset category EGR rate is compared with the EGR rate value array. Based on the comparison results, the EGR rate value array and the delay duration array are updated to obtain the actual vehicle boosting closed-loop delay database at the corresponding time.

[0027] In some embodiments, the number of preset category EGR rates in the preset category EGR rate sorting sequence is n;

[0028] The number of reference values ​​in the EGR rate value array is n, and the i-th reference value A in the EGR rate value array is... i It corresponds to the i-th preset category EGR rate in the preset category EGR rate sorting sequence;

[0029] The number of reference durations in each of the aforementioned delay duration arrays is n, and the i-th reference duration B in the delay duration array is... i It corresponds to the i-th preset category EGR rate in the preset category EGR rate sorting sequence;

[0030] i∈[1,n] and is a positive integer;

[0031] In response to the arrival of the acquisition time, the steps of obtaining the current value of the EGR rate of each preset category at the corresponding time, comparing the current value of the EGR rate of each preset category with the EGR rate value array, and updating the EGR rate value array and the delay duration array according to the comparison results include:

[0032] In response to the arrival of the data acquisition time, the corresponding preset EGR rate lower limit endpoint value A0 and preset EGR rate upper limit endpoint value A0 are configured for the current EGR rate value array. n+1 And, respectively configure the corresponding preset duration lower limit endpoint value B0 and preset duration upper limit endpoint value B for each of the current delay duration arrays. n+1 ;

[0033] Obtain the current value of the EGR rate for each preset category at the corresponding time, where the current value of the EGR rate for the i-th preset category is denoted as Q. i ;

[0034] Initialize i = 1;

[0035] Based on the current EGR rate value array, determine the current value range corresponding to the i-th preset category EGR rate [A]. i-1 A i+1 ];

[0036] The current value Q of the EGR rate of the i-th preset category. i Compare with the corresponding value range [A] i-1 A i+1 Compare them;

[0037] If we compare Q i ∈[A i-1 A i+1 If i > n, then the EGR rate value array and each of the delay duration arrays are not adjusted, and the size of i and n is further compared.

[0038] If the comparison shows i < n, then i is incremented by 1, and the comparison range corresponding to the current EGR rate of the i-th preset category is determined again based on the current EGR rate value array. i-1 A i+1 The steps;

[0039] If i=n is found, it means that the initial adjustment process is over. Further adjustments are made to each of the delay duration arrays based on the current EGR rate value array and the preset transition coefficient.

[0040] If we compare Q i [A i-1 A i+1 ], then according to Q i The EGR rate value array is adjusted accordingly, and the delay duration arrays are adjusted based on the adjustment of the EGR rate value array, until Q... i The value range corresponding to the i-th preset category EGR rate determined by the adjusted EGR rate value array is [A]. i-1 A i+1 ]Inside.

[0041] In some embodiments, according to Q i The EGR rate value array is adjusted accordingly, and the delay duration arrays are adjusted based on the adjustment of the EGR rate value array, until Q...i The value range corresponding to the i-th preset category EGR rate determined by the adjusted EGR rate value array is [A]. i-1 A i+1 The steps within [the document] include:

[0042] If we compare Q i <A i-1 Then, determine the value greater than Q from the current EGR rate value array. i And closest to Q i A reference value, denoted as m, is inserted at the position preceding the reference value originally located at position m in the EGR rate value array, where Q is inserted. i Then, the reference value at position n+1 in the EGR rate value array is deleted to adjust the EGR rate value array; simultaneously, based on the interpolation algorithm, an interpolation value is inserted at the position preceding the reference duration at position m in each of the delay duration arrays. i The corresponding reference durations are used to shift the positions of the reference durations originally located at positions m to n in each of the delay duration arrays one position to the right, and then the reference duration at position n+1 in each of the delay duration arrays is deleted to adjust each of the delay duration arrays; after the adjustment of the EGR rate value array and each of the delay duration arrays is completed, the value comparison range corresponding to the current preset category EGR rate is determined again based on the current EGR rate value array [A]. i-1 A i+1 The steps;

[0043] If we compare Q i >A i-1 Then, from the current EGR rate value array, determine the value less than Q. i And closest to Q i A reference value, denoted as m, is inserted at the position following the reference value originally located at position m in the EGR rate value array, where Q is inserted. i Then, the reference value at the first position in the EGR rate value array is deleted to adjust the EGR rate value array; simultaneously, based on the interpolation algorithm, an interpolation value is inserted at the position after the reference duration at the m-th position in each of the delay duration arrays, interpolating the value with respect to Q. i The corresponding reference duration is then deleted, and the reference duration at the first position in each of the delay duration arrays is adjusted. After adjusting the EGR rate value array and each of the delay duration arrays, the value comparison range corresponding to the current preset category EGR rate is determined again based on the current EGR rate value array. i-1 A i+1 The steps are as follows.

[0044] In some embodiments, the step of further adjusting each of the delay duration arrays based on the current EGR rate value array and a preset transition coefficient includes:

[0045] Each of the aforementioned delay duration arrays is used as a target delay duration array, and the target delay duration arrays are adjusted according to the following steps:

[0046] Based on the reference values ​​in the EGR rate array and the reference durations in the target delay duration array obtained after the initial adjustment process, a first eigenvalue array and a second eigenvalue array are determined. The first eigenvalue array contains n sequentially arranged first eigenvalues, and the second eigenvalue array contains n sequentially arranged second eigenvalues. The i-th first eigenvalue in the first eigenvalue array is D... i1 and the i-th first eigenvalue D in the second eigenvalue array i2 Determined by the following formula:

[0047]

[0048]

[0049] This represents the i-th reference value in the EGR rate array obtained after the initial adjustment process. This represents the i-th reference duration in the target delay duration array obtained after the initial adjustment process;

[0050] Based on the first feature value array, the second feature value array, and the preset transition coefficient, the target delay duration array is further adjusted in the following manner:

[0051] Among them, the first reference duration C1 in the further adjusted target delay duration array:

[0052] C1=B1'

[0053] The second reference duration C2 in the further adjusted target delay duration array:

[0054] C2=max(B2',C1)

[0055] The reference durations from the 3rd to the nth in the further adjusted target delay duration array are determined based on the following formula:

[0056]

[0057] Where i∈[2,n-1], C i This represents the i-th reference duration in the further adjusted target delay duration array. and There are two preset transition coefficients and , max() represents the function that takes the largest value.

[0058] In some embodiments, the various preset categories of EGR rates include: minimum EGR rate, actual EGR rate, target EGR rate, modified EGR rate, and maximum EGR rate.

[0059] Secondly, this disclosure provides an engine system shutdown control method, including:

[0060] In response to the engine shutdown request command, the engine system shutdown delay determination method provided in the first aspect is used to determine the shutdown delay duration of the engine system in the state of fuel cut-off and engine rotation driven by the motor;

[0061] The engine system controls the engine to cut off fuel, close the EGR valve, and fully open the mixing valve, while using an electric motor to drive the engine to rotate, maintaining the engine's current operating conditions and continuing operation for the specified shutdown delay time.

[0062] After the specified shutdown delay period ends, the engine is controlled to shut down.

[0063] Thirdly, this disclosure provides an engine system shutdown delay determination system, wherein the engine system shutdown delay determination system is configured to implement the engine system shutdown delay determination method as described in any one of claims 1 to 9, and the engine system shutdown delay determination system includes:

[0064] The first acquisition module is configured to, in response to an engine shutdown request command, acquire the value of the actual EGR rate of the current engine system as the actual EGR rate value before shutdown, and acquire the value of the proportion of exhaust gas length in the first pipeline from the EGR valve to the throttle valve in the current engine system as the proportion of exhaust gas length before shutdown.

[0065] The second acquisition module is configured to acquire, based on the actual EGR rate value before shutdown, the exhaust gas length ratio value before shutdown, and a pre-acquired real-vehicle turbocharged closed-loop delay database, the time taken for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve while in turbocharged closed-loop operation, as the basic delay time; wherein, the real-vehicle turbocharged closed-loop delay database records the reference time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve using multiple different EGR rate values ​​when the first pipeline corresponds to multiple different exhaust gas length ratio values;

[0066] The determination module is configured to determine, based on the basic delay duration, the duration during which the engine system, in a state of fuel cut-off and engine rotation driven by the motor, discharges all exhaust gas in the first pipeline from the throttle valve, and uses this duration as the first delay duration;

[0067] The third acquisition module is configured to acquire the flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder, as the second delay time.

[0068] The calculation module is configured to sum the first delay duration and the second delay duration to obtain the engine system shutdown delay duration.

[0069] Fourthly, this disclosure provides an engine system shutdown delay control system, comprising:

[0070] The engine system shutdown delay determination system adopts the engine system shutdown delay determination system provided by the third party;

[0071] The first control module is configured to control the engine fuel cut-off, EGR valve closure, and mixing valve full opening within the engine system, and to use a motor to drive the engine to rotate, maintaining the current operating condition of the engine and continuing to run for the shutdown delay period.

[0072] The second control module is configured to control the engine to stop after the shutdown delay period ends.

[0073] Fifthly, this disclosure provides a vehicle, which includes: an engine system shutdown delay control system as described in the fourth aspect.

[0074] Sixthly, embodiments of this disclosure provide an electronic device, comprising:

[0075] One or more processors;

[0076] Memory, used to store one or more programs;

[0077] When the one or more programs are executed by the one or more processors, the one or more processors implement any of the methods provided in the first or second aspect.

[0078] In a seventh aspect, embodiments of this disclosure provide a computer-readable medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of any of the methods provided in the first or second aspect.

[0079] The technical solution disclosed herein can, after the engine system receives an engine stop request command, obtain the actual EGR rate value before stop and the proportion of exhaust gas length in the first pipeline before stop; based on the actual EGR rate value before stop, the proportion of exhaust gas length before stop, and the real vehicle turbocharged closed-loop delay database, obtain the basic delay time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve when in turbocharged closed-loop operation; based on the basic delay time, determine the time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve when in fuel cut-off and engine rotation driven by the electric motor, as the first delay. The first delay duration is the time taken for gas to flow from the throttle valve to the exhaust port of the engine cylinder within the engine system. This is used as the second delay duration. The first delay duration is summed with the second delay duration to obtain the engine shutdown delay duration when the fuel system is cut off and the engine is driven by the electric motor. This helps to completely expel the exhaust gas from the intake system and greatly reduce the exhaust gas in the engine cylinder, thus effectively reducing the impact of exhaust gas on the next start-up performance. In addition, since the engine is driven by the electric motor during the delay operation, the engine does not consume fuel, so the delayed shutdown process does not lead to an increase in fuel consumption, resulting in fuel economy. Attached Figure Description

[0080] Figure 1 This is a schematic diagram of the engine system involved in the technical solution disclosed herein;

[0081] Figure 2 A flowchart of a method for determining engine system shutdown delay provided in an embodiment of this disclosure;

[0082] Figure 3 A flowchart illustrating another method for determining engine system shutdown delay provided in this embodiment of the disclosure;

[0083] Figure 4 This is an optional implementation method flow for step Sa23 in the embodiments of this disclosure;

[0084] Figure 5 A flowchart of an engine system shutdown control method provided in this disclosure embodiment;

[0085] Figure 6 A structural block diagram of an engine system shutdown delay determination system provided in this embodiment of the disclosure;

[0086] Figure 7 A structural block diagram of an engine system shutdown delay control system provided in this disclosure embodiment;

[0087] Figure 8 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0088] To enable those skilled in the art to better understand the technical solutions of the present invention, exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0089] Where there is no conflict, the various embodiments of the present invention and the features thereof may be combined with each other.

[0090] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0091] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0092] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and the invention, and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein.

[0093] In the technical solution of this invention, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information all comply with relevant laws and regulations and do not violate public order and good morals. The use of user data in this technical solution follows relevant national laws and regulations (e.g., the "Information Security Technology - Personal Information Security Specification"). For example: appropriate measures are taken for personal information access control; restrictions are imposed on the display of personal information; the purpose of using personal information does not exceed the scope of direct or reasonable association; and explicit identity targeting is eliminated when using personal information to avoid precisely locating a specific individual.

[0094] Figure 1 This is a schematic diagram of the engine system involved in the technical solution disclosed herein. Figure 1 As shown, an engine system generally includes an air filter 1; a mixing valve 2 connected to the air filter, configured to regulate the pressure at the outlet of the EGR valve 10, increasing the pressure difference across the EGR valve 10, with two airflow passages extending from the mixing valve 2; a compressor 3 connected to one of the airflow passages of the mixing valve 2; a throttle valve 4 connected to the compressor 3, wherein the throttle valve 4 has a boost temperature and pressure sensor at its inlet and an intake air temperature and pressure sensor at its outlet, and the throttle valve 4 body has a position sensor and an actuator; an engine 5 connected to the throttle valve 4, configured to compress fresh air for boosting; and a turbine 6 connected to the engine 5, configured to control the opening of the exhaust bypass valve. The following components are connected to the turbine 6: a catalyst 7; a particulate filter 8; an EGR cooler 9 installed on another airflow path of the mixing valve 2, configured to receive and cool the exhaust gas output from the particulate filter 8 to increase the exhaust gas flow rate; an EGR valve 10 connected at one end to the EGR cooler 9 and at the other end to the mixing valve 2, configured to control the exhaust gas flow rate entering the cylinder; a temperature sensor 11 installed between the EGR valve 10 and the EGR cooler 9, configured to detect the exhaust gas temperature entering the EGR valve 10; and a differential pressure sensor 12 connected to the EGR valve 10, configured to detect the pressure at the inlet and outlet of the EGR valve 10.

[0095] Figure 2 This is a flowchart illustrating a method for determining engine system shutdown delay, provided as an embodiment of this disclosure. Figure 2 As shown, the method for determining the engine system shutdown delay includes:

[0096] Step S1: In response to the engine stop request command, obtain the actual EGR rate of the current engine system as the actual EGR rate value before the stop, and obtain the exhaust gas length ratio in the first pipeline from the EGR valve to the throttle valve in the current engine system as the exhaust gas length ratio value before the stop.

[0097] Among them, the exhaust gas length ratio in the first pipeline refers to the ratio of the length of the pipeline containing exhaust gas to the total length of the first pipeline. The exhaust gas length ratio before shutdown reflects the amount of exhaust gas in the first pipeline from the EGR valve to the throttle valve before shutdown; the actual EGR rate before shutdown reflects the utilization status of exhaust gas by the engine system before shutdown.

[0098] The actual EGR rate of the current engine system can be read in real time directly through the external control system of the engine system.

[0099] The proportion of exhaust gas length in the first pipeline can be obtained by measuring the detection status of exhaust gas detection sensors deployed in the first pipeline. Specifically, S exhaust gas detection sensors are evenly deployed in the first pipeline. These sensors can detect whether exhaust gas exists at corresponding locations within the first pipeline, thus the proportion of exhaust gas length in the first pipeline can be obtained based on the detection results of these S sensors. For example, if s1 exhaust gas detection sensors detect exhaust gas and S-s1 exhaust gas detection sensors do not detect exhaust gas, then the proportion of exhaust gas length in the first pipeline is s1 / S.

[0100] In addition, even without an exhaust gas detection sensor, the proportion of exhaust gas length in the first pipeline can be calculated based on the operating status of the EGR valve. Specifically, assuming that the mass flow rate of exhaust gas is the same and the overall diameter is the same during each unit of time (e.g., 10ms), the length of exhaust gas that has flowed through the first pipeline after entering the EGR valve can be obtained per unit of time. By removing exhaust gas longer than the entire length of the first pipeline, the starting position of the exhaust gas in the first pipeline can be determined. By recording the length of each segment of exhaust gas during the continuous opening of the EGR valve, only the length of one or several segments of exhaust gas before the shutdown request time is retained, and the position of these segments of exhaust gas in the first pipeline (there may be one or more segments of exhaust gas in the first pipeline) can be calculated. Thus, the total length of exhaust gas in the first pipeline can be obtained, and the proportion of exhaust gas length in the first pipeline can be calculated.

[0101] Step S2: Based on the actual EGR rate value before shutdown, the exhaust gas length ratio value before shutdown, and the pre-acquired real vehicle turbocharged closed-loop delay database, obtain the time it takes for the engine system to discharge all the exhaust gas in the first pipeline from the throttle valve when it is in turbocharged closed-loop working state, and use it as the basic delay time.

[0102] The real-vehicle turbocharged closed-loop delay database records the reference time for the engine system to exhaust all exhaust gas from the first pipeline through the throttle valve under different EGR rate values ​​when the engine system is in turbocharged closed-loop operation, with each of the first pipeline corresponding to different exhaust gas length ratios. In other words, the real-vehicle turbocharged closed-loop delay database records the reference time for all exhaust gas to be exhausted from the throttle valve for different combinations of exhaust gas length ratios and EGR rate values ​​when the engine system is in turbocharged closed-loop operation.

[0103] In practical applications, the duration corresponding to the actual EGR rate value and the exhaust gas length ratio before shutdown can be obtained from the actual vehicle turbocharger closed-loop delay database by looking up a table and using linear interpolation. Specifically, when the combination of the actual EGR rate value and the exhaust gas length ratio before shutdown directly exists in the actual vehicle turbocharger closed-loop delay database, the reference duration corresponding to this combination can be determined directly from the database by looking up a table. When the combination of the actual EGR rate value and the exhaust gas length ratio before shutdown does not directly exist in the database, the duration corresponding to this combination can be obtained by using interpolation algorithms (e.g., single linear interpolation, bilinear interpolation) based on some data similar to the actual EGR rate value and the exhaust gas length ratio before shutdown recorded in the database.

[0104] In practical applications, the more combinations of "multiple different exhaust length percentage values" and "multiple different EGR rate values" recorded in the real vehicle turbocharged closed-loop delay database, the better the accuracy of the final obtained basic delay time.

[0105] Step S3: Based on the basic delay duration, determine the duration during which the engine system, in a state of fuel cut-off and engine rotation driven by the electric motor, discharges all the exhaust gas in the first pipeline from the throttle valve, and use this as the first delay duration.

[0106] In this disclosure, engine shutdown can be delayed by controlling the engine fuel cut-off. Fuel cut-off is good for engine fuel economy. Since the exhaust energy of the engine is reduced due to fuel cut-off, the turbocharger cannot work and the turbocharger does not enter the closed loop state. Therefore, the basic delay time obtained in step S2 needs to be corrected to obtain the first delay time when the engine system is in the state of fuel cut-off and the engine is driven by the motor to rotate, so that all the exhaust gas in the first pipeline is discharged from the throttle valve.

[0107] In some embodiments, step S3 includes:

[0108] Determine whether the engine system is in a boost closed-loop operating state or not when an engine stop request command is received;

[0109] When it is determined that the engine system is in a boost closed-loop operating state when the engine stop request command is received, the first delay duration is determined based on the following formula:

[0110]

[0111] in, This is the first delay duration. Based on the delay duration, The preset delay factor is used. ∈(1,1.2).

[0112] In the disclosed method, although the engine system is in a boost closed-loop operating state when an engine stop request command is received, the actual exhaust capacity of the engine is weaker than ideal due to energy loss in the transmission between the motor and the engine when the motor drives the engine to maintain the operating condition at the time of receiving the engine stop request command. Therefore, the basic delay time needs to be further delayed, and the final first delay time should be positively correlated with the basic delay time. Therefore, this disclosure corrects the basic delay time based on a preset delay coefficient r1. At the same time, considering that the energy loss in the transmission between the motor and the engine will not be too large, and the actual exhaust capacity of the engine is only slightly weaker than ideal, the preset delay coefficient r1 is slightly greater than 1. For example, r1 can take values ​​such as 1.05, 1.1, 1.2, etc.

[0113] If it is determined that the engine system was not in the boost closed-loop operating state when the engine stop request command was received, then the engine speed at the time the engine stop request command was received is obtained. Engine coolant temperature Atmospheric pressure Throttle inlet pressure Throttle outlet pressure The first delay duration is determined based on the following formula:

[0114]

[0115] in, To determine the throttle body inlet and outlet pressure ratio and engine speed The first adjustment coefficient is obtained by looking up the correspondence between the two parameters and the first preset calibration table. To determine based on engine coolant temperature Atmospheric pressure The second adjustment coefficient is obtained by looking up the second preset calibration correspondence table.

[0116] The first preset calibration correspondence table records multiple combinations of throttle inlet / outlet pressure ratios and engine speeds, along with their corresponding adjustment coefficients; the second preset calibration correspondence table records multiple combinations of engine coolant temperature and atmospheric pressure, along with their corresponding adjustment coefficients.

[0117] In the disclosed method, when the engine system is not in the boost closed-loop operating state when an engine stop request command is received, it is necessary to combine multiple parameters to correct the basic delay duration obtained in step S2. Specifically, this disclosure introduces two characteristic coefficients: one is based on the throttle inlet / outlet pressure ratio. The characteristic coefficients obtained from the engine speed n (i.e., the first adjustment factor mentioned above), the second is based on engine coolant temperature. and atmospheric pressure The obtained characteristic coefficients (i.e., the second adjustment factor mentioned above).

[0118] Characteristic coefficient 1 and characteristic coefficient 2 The determination logic is based on whether restarting the engine after it has stopped affects the engine speed fluctuation during the start-up process. Calibration is performed based on the engine speed fluctuation during start-up. The performance index for engine speed fluctuation during start-up can be referenced to the following: after the generator disengages from the engine (i.e., the generator torque request is within a fluctuation range of 0 Nm, ±3 Nm in this example), the engine speed should not be lower than a preset value (25 rpm / s in this example) before it reaches its maximum speed. If the speed fluctuation does not meet the preset value, the corresponding speed should be increased appropriately. and Otherwise, reduce appropriately. and The final result and It meets the speed control target after the next engine start.

[0119] Based on the above principles, different throttle valve inlet and outlet pressure ratios can be simulated and tested using an engine bench testing system. With engine speed combination The corresponding optimal coefficient value, i.e., the adjustment coefficient. Thus, a first preset calibration correspondence table is obtained; in step S3, the engine speed at the time the engine stop request command is received can be used as a reference. Throttle inlet pressure Throttle outlet pressure The first adjustment coefficient is obtained from the first preset calibration correspondence table by looking up a table or interpolation. .

[0120] Similarly, different engine coolant temperatures can be simulated and tested using an engine bench testing system. With atmospheric pressure combination The corresponding optimal coefficient value, i.e., the adjustment coefficient. This yields the second preset calibration correspondence table. In step S3, the engine coolant temperature at the time the engine stop request command is received can be used as a reference. Atmospheric pressure The second adjustment coefficient is obtained from the first preset calibration correspondence table by looking up a table or interpolation. .

[0121] Step S4: Obtain the flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder, as the second delay time.

[0122] The exhaust gas expelled from the throttle valve needs to re-enter the engine cylinders, so it's necessary to expel as much exhaust gas as possible from the engine cylinders. It should be noted that in the technical solution disclosed herein, the engine cylinders also generate a certain amount of exhaust gas during the delayed operation process. Therefore, in practical applications, it's impossible to completely expel all the exhaust gas from the engine cylinders. However, it can at least completely expel the exhaust gas from the intake system (the piping section located before the engine) and significantly reduce the amount of exhaust gas in the engine cylinders, thus effectively reducing the impact of exhaust gas on the next starting performance.

[0123] Step S5: Sum the first delay duration and the second delay duration to obtain the engine system shutdown delay duration.

[0124] Based on the above, the technical solution disclosed herein can, after the engine system receives an engine stop request command, obtain the actual EGR rate value before stop and the proportion of exhaust gas length in the first pipeline before stop; based on the actual EGR rate value before stop, the proportion of exhaust gas length before stop, and the real vehicle turbocharged closed-loop delay database, obtain the basic delay time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve under turbocharged closed-loop operating conditions; and based on the basic delay time, determine the time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve under fuel cut-off and motor-driven engine rotation conditions, and then... The first delay duration is calculated as follows: the flow time of gas from the throttle valve to the exhaust port of the engine cylinder is calculated as the second delay duration; the first delay duration and the second delay duration are summed to obtain the engine shutdown delay duration when the fuel system is cut off and the engine is driven by the electric motor. This helps to completely expel the exhaust gas in the intake system and greatly reduce the exhaust gas in the engine cylinder, thus effectively reducing the impact of exhaust gas on the next start-up performance. In addition, since the engine is driven by the electric motor during the delay operation, the engine does not consume fuel, so the delayed shutdown process does not lead to an increase in fuel consumption, making it fuel-efficient.

[0125] Figure 3 A flowchart illustrating another method for determining engine system shutdown delay provided in an embodiment of this disclosure. (See flowchart for example.) Figure 3 As shown, the method for determining the engine system shutdown delay includes not only steps S1 to S5 in the previous embodiments, but also step Sa before step S1. Step Sa will be described in detail below.

[0126] Step Sa: Obtain the actual vehicle booster closed-loop delay database.

[0127] Step Sa specifically includes:

[0128] Step Sa1: Obtain the test result database.

[0129] The test results database records the test durations taken by using an engine bench test system to simulate the operation of the engine system in a boost closed-loop state, with the EGR valve closed and the mixing valve fully open. The test results show the test durations taken by using the engine system in a boost closed-loop state and the initial EGR rate values ​​corresponding to different preset categories of EGR rates to discharge all the exhaust gas from the first pipeline through the throttle valve under various preset exhaust gas length ratios.

[0130] In some embodiments, the various preset EGR rates include: minimum EGR rate, actual EGR rate, target EGR rate, adjusted EGR rate, and maximum EGR rate. The specific definitions of each preset EGR rate are as follows:

[0131] Among them, the minimum EGR rate (determined by the current operating conditions) is the minimum allowable EGR rate under the current operating conditions. If the EGR rate is too low, it will cause the EGR valve to fluctuate, resulting in serious fluctuations in exhaust gas and unstable control. The minimum EGR rate is designed based on this.

[0132] Actual EGR rate: The actual EGR rate under the current operating conditions.

[0133] Target EGR rate: The ideal EGR rate requested under the current operating conditions.

[0134] Maximum EGR rate (determined by current operating conditions): The maximum allowable EGR rate under current operating conditions, determined based on exhaust temperature protection, knock protection, and the engine's own capabilities.

[0135] Corrected EGR rate: A new intermediate EGR rate is interpolated based on the minimum EGR rate, maximum EGR rate, and actual EGR rate. When the EGR rate accuracy is low, introducing this corrected EGR rate can improve the EGR rate control accuracy. The calculation method for this corrected EGR rate is as follows:

[0136] (1) When the "actual EGR rate + minimum EGR rate" is greater than the "maximum EGR rate / 2", the corrected EGR rate is equal to the maximum value of the "minimum EGR rate" and the "actual EGR rate - interpolation margin Y". The interpolation margin is a fixed constant. In this example, 0.08 is chosen because when the EGR rate accuracy is low, the EGR rate control accuracy can be improved by introducing this corrected EGR rate.

[0137] (2) When the "actual EGR rate + minimum EGR rate" is not greater than the "maximum EGR rate / 2", the corrected EGR rate is equal to the maximum value of the "maximum EGR rate" and the "actual EGR rate + interpolation margin Y". The interpolation margin is a fixed constant, and in this example, 0.08 is chosen. The basis for this choice is that introducing this corrected EGR rate improves the EGR rate control accuracy by 1% (when the EGR rate accuracy is less than 2%).

[0138] It should be noted that the method of reading the values ​​of the five EGR rates of the engine system—minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate—at one or more times as needed is a conventional technique in this field, and this disclosure does not limit it. For example, patent applications with publication numbers CN115450775A, CN115585070A, and CN119801755A all describe methods for obtaining different types of EGR rates. In the technical solution of this disclosure, the values ​​of the minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate of the engine system can be directly read at the required times using existing technical means.

[0139] As an example, several different preset exhaust length percentages are 0.01, 0.3, 0.5, 0.8, and 1. This design can effectively cover the range of 0 to 1 for the "exhaust length percentage".

[0140] The process of obtaining a test result database based on an engine bench testing system is as follows:

[0141] First, the engine system is simulated on an engine bench testing system under preset test conditions (either a condition set according to actual needs or a randomly selected condition). Then, the values ​​of the five EGR rates—minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate—are read and used as the initial values ​​for the five EGR rates. For ease of description, the initial values ​​of the five EGR rates are denoted as a1, a2, a3, a4, and a5, respectively.

[0142] Then, using an engine bench test system, the test time was simulated to determine the initial settings of the engine system using five different EGR rates to discharge all the exhaust gas in the first pipeline from the throttle valve under various preset exhaust gas length ratios for different conditions in the first pipeline.

[0143] Taking the test duration of the engine system operating at the initial values ​​corresponding to the five EGR rates to discharge all the exhaust gas in the first pipeline from the throttle valve when the exhaust gas length ratio of the first pipeline is 0.01 as an example.

[0144] First, make the following settings: 1) Set the engine system to be in a boost closed-loop working state, with the EGR valve closed and the mixing valve fully open; 2) Set the engine bench test system to work at a fixed speed and load (fixed working conditions can be designed according to actual needs or fixed working conditions can be randomly determined); 3) Set the exhaust gas length ratio of the first pipeline to 0.01 when the engine system starts working.

[0145] Then, based on the above settings, the following 5 tests were conducted:

[0146] Test 1: Add a setting for the engine system to operate with the actual EGR rate as a1 (the initial setting of the minimum EGR rate); after completing the above setting, use the engine bench test system to conduct a simulation test and obtain the test time when the engine system operates with the actual EGR rate as a1 and all the exhaust gas in the first pipeline is discharged through the throttle valve, which is recorded as t11.

[0147] Test 2: Add a setting for the engine system to operate with the actual EGR rate as a2 (the initial setting of the actual EGR rate); after completing the above setting, use the engine bench test system to conduct a simulation test and obtain the test time when the engine system operates with the actual EGR rate as a2 and all the exhaust gas in the first pipeline is discharged through the throttle valve, which is recorded as t12.

[0148] Test 3: Add a setting for the engine system to operate with the actual EGR rate as a3 (the initial value of the target EGR rate); after completing the above setting, use the engine bench test system to conduct a simulation test and obtain the test time when the engine system operates with the actual EGR rate as a3 and all the exhaust gas in the first pipeline is discharged through the throttle valve, which is recorded as t13.

[0149] Test 4: Add a setting for the engine system to operate with an actual EGR rate of a4 (correcting the initial EGR rate setting); after completing the above settings, use an engine bench test system to perform a simulation test and obtain the test time when the engine system operates with an actual EGR rate of a4 and all the exhaust gas in the first pipeline is discharged through the throttle valve, which is recorded as t14.

[0150] Test 5: Add a setting for the engine system to operate with an actual EGR rate of a5 (the initial setting of the maximum EGR rate); after completing the above setting, use the engine bench test system to conduct a simulation test and obtain the test time when the engine system operates with an actual EGR rate of a5 and all the exhaust gas in the first pipeline is discharged through the throttle valve, which is recorded as t15.

[0151] Therefore, the test times for the engine system to discharge all the exhaust gas in the first pipeline from the throttle valve using five different initial EGR rates under the condition that the exhaust gas length of the first pipeline accounts for 0.01% of the total length can be obtained. These times are t11, t12, t13, t14, and t15.

[0152] Based on the same testing method, the test duration for the engine system to discharge all the exhaust gas in the first pipeline from the throttle valve can be obtained when the exhaust gas length ratio of the first pipeline is 0.3, 0.5, 0.8 and 1, respectively, under the condition of the engine system in the boost closed-loop operation. The test duration is obtained by using the initial values ​​of 5 different EGR rates (minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate and maximum EGR rate in order) to operate.

[0153] Among them, when the exhaust gas length of the first pipeline is 0.3% as obtained through simulation test, the test duration for the engine system to operate under the boost closed-loop working state with five different EGR rates (in order: minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate) to discharge all the exhaust gas in the first pipeline from the throttle valve is t21, t22, t23, t24, and t25.

[0154] The test durations for exhausting all the exhaust gas in the first pipeline through the throttle valve when the exhaust gas length of the first pipeline accounts for 0.5% of the total length obtained through simulation testing are t31, t32, t33, t34, and t35, respectively, when the engine system is in the boost closed-loop operation state and five different EGR rates (in order: minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate) are used to ensure that all the exhaust gas in the first pipeline is discharged from the throttle valve.

[0155] The test durations obtained through simulation tests, when the exhaust gas length ratio of the first pipeline is 0.8, and the engine system is in the boost closed-loop operation state, are t41, t42, t43, t44, and t45, respectively, when the initial values ​​of five different EGR rates (minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate) are used to discharge all the exhaust gas in the first pipeline from the throttle valve.

[0156] The test durations for exhausting all the exhaust gas in the first pipeline through the throttle valve when the exhaust gas length of the first pipeline is 1% obtained by simulation test are t51, t52, t53, t54, and t55, respectively, when the engine system is in the boost closed-loop working state and uses five different EGR rates (in order: minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate) to discharge the exhaust gas through the throttle valve.

[0157] Table 1. Data Tables in the Test Results Database

[0158]

[0159] Referring to Table 1 above, based on the aforementioned simulation test results, a database of test results for the engine system under boosted closed-loop operating conditions can be obtained.

[0160] Step Sa2: During actual vehicle operation, the values ​​of various preset categories of EGR rates of the engine system are acquired in real time according to preset sampling rules. The test result database is updated according to the values ​​of various different EGR rates acquired at each sampling time to obtain the actual vehicle boosting closed-loop delay database.

[0161] In this disclosure, factors such as the different EGR exhaust gases and the nonlinearity of the EGR pipeline and intake system affect the nonlinear control of charging efficiency and throttle opening, thus influencing the time it takes for exhaust gas to flow from the EGR valve out of the throttle (i.e., the time it takes for all the exhaust gas in the first pipeline to be discharged through the throttle). This time is not linearly proportional to the proportion of exhaust gas length in the first pipeline, therefore, it is necessary to improve the accuracy of time estimation under different operating conditions in actual vehicles. Therefore, the test result database needs to be updated based on actual vehicle operation.

[0162] In some embodiments, step Sa2 above includes:

[0163] Step Sa21: Sort all preset category EGR rates in ascending order of their corresponding initial EGR rate values ​​to obtain a preset category EGR rate sorting sequence, and initialize an EGR rate value array corresponding to the preset category EGR rate sorting sequence.

[0164] The EGR rate value array contains reference values ​​for each preset category of EGR rate, sorted according to the preset category EGR rate sequence. When the EGR rate value array is initialized, the reference values ​​for each preset category of EGR rate are the corresponding initial EGR rate values.

[0165] In this embodiment, it is assumed that the initial values ​​a1, a2, a3, a4, and a5 of the five EGR rates—minimum EGR rate, actual EGR rate, target EGR rate, modified EGR rate, and maximum EGR rate—satisfy the following order: a1 < a2 < a3 < a4 < a5. Therefore, the order of the five EGR rates in the preset category EGR rate sorting sequence is: minimum EGR rate, actual EGR rate, target EGR rate, modified EGR rate, and maximum EGR rate. The reference values ​​for the five EGR rates recorded in the EGR rate value array are A1, A2, A3, A4, and A5, respectively. Therefore, when initially generating the EGR rate value array, A1 = a1, A2 = a2, A3 = a3, A4 = a4, and A5 = a5.

[0166] It should be noted that the arrangement of the initial values ​​of the minimum EGR rate, actual EGR rate, target EGR rate, corrected EGR rate, and maximum EGR rate in ascending order is merely an example in this disclosure and does not limit the technical solution of this disclosure. In practical applications, the relationship between the initial values ​​of the actual EGR rate, target EGR rate, and corrected EGR rate needs to be determined based on the simulation test results of the engine bench test system. For example, the initial value of the actual EGR rate may be greater than the initial value of the target EGR rate, and the initial value of the corrected EGR rate may be less than the initial value of the target EGR rate, etc.

[0167] Step Sa22: Initialize the database based on the test results to generate multiple delay duration arrays that correspond one-to-one with the proportion of different preset exhaust gas lengths.

[0168] The delay duration array contains the reference duration for the engine system to use the reference values ​​of each preset category EGR rate to delay operation under the corresponding preset exhaust gas length ratio in order to discharge all exhaust gas in the first pipeline from the throttle valve. The delay duration array also contains the reference duration corresponding to each preset category EGR rate in the preset category EGR rate sorted sequence. When the delay duration array is initialized, the reference duration corresponding to each preset category EGR rate is the corresponding test duration recorded in the test result database.

[0169] Taking the case where the proportions of different preset exhaust gas lengths are 0.01, 0.3, 0.5, 0.8, and 1 respectively as an example, there are 5 different preset exhaust gas lengths. In step Sa22, 5 delay duration arrays corresponding to the 5 different preset exhaust gas lengths will be generated. When the 5 delay duration arrays are initially generated, the reference duration recorded in each delay duration array is the corresponding test duration recorded in the test result database.

[0170] It should be noted that, since the delay duration array records the reference duration corresponding to each preset category EGR rate according to the preset category EGR rate sorting sequence, and the preset category EGR rate sorting sequence is sorted in ascending order of the corresponding initial values, the reference durations in each delay duration array are also sorted in ascending order. This setting is to facilitate subsequent updates to the EGR rate value array and the delay duration array based on the actual vehicle operating status.

[0171] Step Sa23: During actual vehicle operation, in response to the arrival of the acquisition time, the current value of each preset category EGR rate at the corresponding time is obtained. The current value of each preset category EGR rate is compared with the EGR rate value array, and the EGR rate value array and the delay duration array are updated according to the comparison results to obtain the actual vehicle boosting closed-loop delay database at the corresponding time.

[0172] In some embodiments, the number of preset category EGR rates in the preset category EGR rate sorting sequence is n; the number of reference values ​​in the EGR rate value array is n, and the i-th reference value A in the EGR rate array is... i The EGR rate corresponds to the i-th preset category EGR rate in the preset category EGR rate sorting sequence; the number of reference durations in each delay duration array is n, and the i-th reference duration B in the delay duration array is... i The EGR rate corresponds to the i-th preset category EGR rate in the preset category EGR rate sorting sequence; i∈[1,n] and is a positive integer.

[0173] Wherein, when the EGR rates of all preset categories are the minimum EGR rate, the actual EGR rate, the target EGR rate, the corrected EGR rate, and the maximum EGR rate, the value of n is 5.

[0174] Figure 4 This is an optional implementation method flow for step Sa23 in the embodiments of this disclosure. For example... Figure 4 As shown, in some embodiments, step Sa23 includes:

[0175] Step Sa231: In response to reaching the acquisition time, configure the corresponding preset EGR rate lower limit endpoint value A0 and preset EGR rate upper limit endpoint value A0 for the current EGR rate value array. n+1 And, respectively configure the corresponding preset duration lower limit endpoint value B0 and preset duration upper limit endpoint value B for each of the current delay duration arrays. n+1 .

[0176] Among them, the preset duration lower limit endpoint value B0 configured in each delay duration array corresponds to the preset EGR rate lower limit endpoint value A0 configured in the EGR rate value array, and the preset duration upper limit endpoint value B0 configured in each delay duration array corresponds to the preset duration upper limit endpoint value B0.n+1 All are consistent with the preset EGR rate upper limit endpoint value A configured in the EGR rate value array. n+1 Correspondingly.

[0177] The preset EGR rate lower limit endpoint value A0 can be a pre-set fixed value (e.g., 0), or it can be obtained by multiplying the current reference value A1 of the minimum EGR rate in the current EGR rate value array by a coefficient greater than 0 and less than 1 (e.g., a coefficient of 0.5). The preset EGR rate upper limit endpoint value A... n+1 It can be a pre-set fixed value (e.g., 0.32, the maximum EGR rate in the engine system generally does not exceed 0.3), or it can be the current reference value A of the maximum EGR rate in the current EGR rate value array. n It is obtained by multiplying by a coefficient greater than 1 and less than 2 (for example, a coefficient of 1.1).

[0178] Similarly, the preset lower limit endpoint value B0 can be a pre-set fixed value (e.g., 0), or it can be obtained by multiplying the minimum reference duration B1 in the current delay duration array by a coefficient greater than 0 and less than 1 (e.g., the coefficient is 0.5); the preset upper limit endpoint value B n+1 It can be a pre-set fixed value (e.g., 0.5s), or it can be based on the maximum reference duration B in the current delay duration array. n It is obtained by multiplying by a coefficient greater than 1 and less than 2 (for example, a coefficient of 1.1).

[0179] Preset EGR rate lower limit endpoint A0, preset EGR rate upper limit endpoint A n+1 Preset duration lower limit endpoint value B0, preset duration upper limit endpoint value B n+1 These values ​​are all for the convenience of subsequent calculations; their specific values ​​will not have a substantial impact on subsequent processing. It is only necessary to ensure that A0 < A1, A n <A n+1 B0 < B1, B n <B n+1 That's all.

[0180] Step Sa232: Obtain the current value of the EGR rate of each preset category at the corresponding time, where the current value of the EGR rate of the i-th preset category is denoted as Q. i .

[0181] Step Sa233: Initialize i=1.

[0182] Step Sa234: Determine the reference range of the current EGR rate for the i-th preset category based on the current EGR rate value array [A]. i-1 A i+1].

[0183] Step Sa235: Set the current value Q of the EGR rate of the i-th preset category. i Compare with the corresponding value range [A] i-1 A i+1 Compare them.

[0184] In step Sa235, if Q is compared... i ∈[A i-1 A i+1 If the EGR rate value array and each delay duration array are not adjusted, then step Sa236 will be executed.

[0185] Step Sa236: Further compare the size of i and n.

[0186] In step Sa236, if i < n, then i is incremented by 1 to update i, and step Sa234 is executed again to process the current value of the EGR rate of the next preset category accordingly.

[0187] In step Sa236, if i=n is found, it means that the current values ​​of all preset category EGR rates collected at the current time have been processed accordingly, the preliminary adjustment process ends, and the subsequent step S238 is executed.

[0188] In step Sa236, if Q is compared... i [A i-1 A i+1 If ], then proceed to step Sa237.

[0189] Step Sa237, according to Q i This involves adjusting the EGR rate array and then adjusting the delay duration arrays accordingly, until Q... i The range of values ​​corresponding to the i-th preset category EGR rate determined by the adjusted EGR rate value array [A] can be located within this range. i-1 A i+1 ]Inside.

[0190] Optionally, step Sa237 includes steps Sa2371 and Sa2372.

[0191] Step Sa2371, when comparing Q in step Sa236 i <A i-1 When that happens, a value greater than Q is determined from the current EGR rate value array. i And closest to Q iA reference value, denoted as m, is inserted at the position preceding the reference value originally located at position m in the EGR rate value array, where Q is located. i Then, the reference value at position n+1 in the EGR rate value array is deleted to adjust the EGR rate value array; simultaneously, based on the interpolation algorithm, an interpolation value is inserted at the position preceding the reference duration at position m in each delay duration array. i The corresponding reference durations are used to shift the positions of the reference durations originally located at positions m to n in each delay duration array one position to the right. Then, the reference duration at position n+1 in each delay duration array is deleted to adjust each delay duration array. After the adjustment of the EGR rate value array and each delay duration array is completed, step Sa234 is executed again.

[0192] Step Sa2372, when comparing Q in step Sa236 i >A i-1 When that happens, determine the value less than Q from the current EGR rate value array. i And closest to Q i A reference value, denoted as m, is inserted at the position following the reference value originally located at position m in the EGR rate value array, where Q is inserted. i Then, the reference value at position 1 in the EGR rate value array is deleted to adjust the EGR rate value array; simultaneously, based on the interpolation algorithm, an interpolation value is inserted at the position after the reference duration at position m in each delay duration array, corresponding to Q. i The corresponding reference duration is then deleted, and the reference duration at the first position in each delay duration array is removed to adjust each delay duration array. After the adjustment of the EGR rate value array and each delay duration array is completed, step Sa234 is executed again.

[0193] Step Sa238: Further adjust each delay duration array based on the current EGR rate value array and the preset transition coefficient.

[0194] In some embodiments, step Sa238 specifically includes: taking each delay duration array as a target delay duration array, and adjusting the target delay duration array according to the following steps:

[0195] Step Sa2381: Based on the reference values ​​in the EGR rate value array and the reference durations in the target delay duration array obtained after the preliminary adjustment process, determine the first feature value array and the second feature value array. The first feature value array includes n first feature values ​​arranged in sequence, and the second feature value array includes n second feature values ​​arranged in sequence. The i-th first feature value in the first feature value array is D. i1 and the i-th first eigenvalue D in the second eigenvalue array i2Determined by the following formula:

[0196]

[0197]

[0198] This represents the i-th reference value in the EGR rate array obtained after the initial adjustment process. This represents the i-th reference duration in the target delay duration array obtained after the initial adjustment process;

[0199] Step Sa2382: Based on the first eigenvalue array, the second eigenvalue array, and the preset transition coefficient, further adjust the target delay duration array in the following manner:

[0200] Among them, the first reference duration C1 in the further adjusted target delay duration array:

[0201] C1=B1'

[0202] The second reference duration C2 in the further adjusted target delay duration array:

[0203] C2=max(B2',C1)

[0204] The reference durations from the 3rd to the nth in the further adjusted target delay duration array are determined based on the following formula:

[0205]

[0206] Where i∈[2,n-1], C i This represents the i-th reference duration in the further adjusted target delay duration array. and There are two preset transition coefficients and , max() represents the function that takes the largest value.

[0207] It should be noted that in this disclosure and The coefficients assigned to the first-order and second-order function characteristics, respectively. and These coefficients are determined based on pre-collected starting influence parameters that affect engine starting (these parameters can be determined by manually assigning initial values ​​and then adjusting them, or directly by manual assignment based on experience). Starting influence parameters may include engine speed. and cooling water temperature and atmospheric temperature wait.

[0208] Specifically, and The determination method involves assessing whether restarting the engine after a shutdown affects engine speed fluctuations during startup, and then calibrating and confirming the results based on the engine speed fluctuations during startup (performance indicators of engine speed fluctuations during startup). This is done under different atmospheric temperatures. and different cooling water temperatures Below, because the delay time is optimized and calibrated for different boosting operating states, the engine speed n affects the delay time. and The impact is relatively small. Through extensive data collection, fitting was performed for different atmospheric temperatures, different water temperatures, and different starting types (e.g., turbocharger inactive - low-speed start or turbocharger activated - high-speed start). and (For example, and You can initially set all values ​​to 1, and then determine whether to adjust them based on the increase in engine speed. and The calibration was performed by verifying the speed effect through data fitting and optimization. Engine speed effect: Specifically, it can be referenced that the engine speed increase rate before the motor disengages during startup is no less than 10 rpm / 10 ms, and that after the motor disengages from the engine (i.e., the motor torque request is within a fluctuation range of 0 Nm, e.g., ±3 Nm), the engine speed should not be lower than a preset value (e.g., 25 rpm / 10 ms) before it reaches its maximum speed. If the speed does not meet these requirements, the corresponding speed should be increased appropriately. and Conversely, reduce appropriately. and The final result and It meets the speed control target after the next engine start.

[0209] Based on the above principles, an engine bench test system can be used to simulate and test the optimal transition coefficient combination (k1, k2) corresponding to different combinations of starting influence parameters (e.g., different combinations of engine speed, coolant temperature, and ambient temperature), and generate a corresponding table of starting influence parameter combinations and transition coefficient combinations. In step Sa2382, the current engine speed can be used as the basis for... and cooling water temperature and atmospheric temperature By querying the table corresponding to the starting influence parameter combination and the transition coefficient combination, the corresponding optimal transition coefficient combination, i.e., the current values ​​of k1 and k2, can be obtained.

[0210] The above step Sa2382 mainly involves debugging the prototype vehicle during the ET stage. The result of the debugging is that a large number of samples on the actual vehicle are arranged according to a normal distribution, that is, the data within the range of μ±3σ meet the drivability evaluation index when the engine starts again. The specific requirements vary depending on the model and all include engine starting performance index requirements.

[0211] Through the processing of steps Sa231 to Sa238 above, the EGR rate value array and delay duration array can be updated based on the actual vehicle operating conditions to obtain the actual vehicle boost closed-loop delay database at the corresponding time.

[0212] Assume that the EGR rate value array obtained after step S238 is completed is [A1',A2',A3',A4',A5'], and the delay duration array corresponding to the exhaust length ratio of 0.01 is [C]. 11 C 12 C 13 C 14 C 15 The delay duration array corresponding to a length ratio of 0.3 for exhaust gas is [C]. 21 C 22 C 23 C 24 C 25 The delay duration array corresponding to a length ratio of 0.5 for exhaust gas is [C]. 31 C 32 C 33 C 34 C 45 The delay duration array corresponding to a length ratio of 0.8 for exhaust gas is [C]. 41 C 42 C 43 C 44 C 45 The delay duration array corresponding to the exhaust length ratio of 1 is [C]. 51 C 52 C 53 C 54 C 55 Based on the above EGR rate value array and delay duration array, the actual vehicle boosting closed-loop delay database at each time point can be obtained.

[0213] Table 2. Data table of the actual vehicle booster closed-loop delay database

[0214]

[0215] The actual EGR rate value before shutdown and the length ratio of exhaust gas before shutdown can be obtained from the real vehicle turbocharger closed-loop delay database shown in Table 2 above by looking up the table and using linear interpolation. The time corresponding to these values ​​can be used as the base delay time.

[0216] The purpose of updating and optimizing using step Sa2 is as follows: In general, linear interpolation is performed based on the test result database shown in Table 1. However, the purpose of step Sa2 is to dynamically optimize the coordinate axis of the table, so that the interpolated duration is also dynamic. The coordinate axis is not fixed. It is adjusted according to the different positions of the current preset EGR rate values, so as to obtain the duration more accurately, rather than simple linear interpolation.

[0217] In some embodiments, the step S4 of obtaining the flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder as the second delay time includes:

[0218] Step S401: Obtain the flow time of gas in the engine system from the throttle valve to the intake port of the engine cylinder, as the first flow time.

[0219] The time it takes for gas to flow from the throttle valve to the intake port of the engine cylinder within the engine system is also called the "gas flow response time," which is a conventional technique in the field, and this disclosure does not limit it. For example, methods for obtaining the gas flow response time are described in patent applications with publication numbers CN111502846A and CN114738135A. In this disclosure, the flow time of gas from the throttle valve to the intake port of the engine cylinder, i.e., the first flow time, can be directly read at the required time using existing technical means.

[0220] Step S402: Obtain the flow time of gas from the intake port of the engine cylinder to the exhaust port of the engine cylinder, as the second flow time.

[0221] The flow time of gas from the intake port to the exhaust port of the engine cylinder is the duration of two engine revolutions. During this time, each cylinder completes its exhaust stroke, ensuring that all exhaust gas flowing in from the intake port is discharged from the exhaust port. Specifically, if the current engine speed n0 is obtained, the duration of one engine revolution is 1 / n0, and the corresponding second flow time is 2 / n0.

[0222] Step S403: Sum the first flow duration and the second flow duration to obtain the second delay duration.

[0223] By using the steps S401 to S403 above, the flow time of gas from the throttle valve to the exhaust port of the engine cylinder in the current engine system can be obtained.

[0224] Based on the same inventive concept, this disclosure also provides an engine system shutdown control method. Figure 5 This is a flowchart illustrating an engine system shutdown control method provided in an embodiment of this disclosure. Figure 5 As shown, the engine system shutdown control method includes:

[0225] BZ1, in response to the engine stop request command, obtains the engine system stop delay determination method to determine the engine system stop delay duration in the state of fuel cut-off and engine rotation driven by electric motor.

[0226] The method for obtaining the downtime duration can be found in the relevant content of the previous embodiments, and will not be repeated here.

[0227] BZ2 controls the engine system to cut off fuel, close the EGR valve, fully open the mixing valve, and use the electric motor to drive the engine to rotate, maintaining the engine's current operating conditions and continuing to run for a shutdown delay period.

[0228] BZ3: After the shutdown delay period ends, control the engine to shut down.

[0229] The technical solution disclosed herein can, after the engine system receives an engine stop request command, obtain the actual EGR rate value before stop and the proportion of exhaust gas length in the first pipeline before stop; based on the actual EGR rate value before stop, the proportion of exhaust gas length before stop, and the real vehicle turbocharged closed-loop delay database, obtain the basic delay time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve when in turbocharged closed-loop operation; based on the basic delay time, determine the time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve when in fuel cut-off and engine rotation driven by the electric motor, and use this as the first delay. Duration; the flow time of gas from the throttle valve to the exhaust port of the engine cylinder is obtained as the second delay duration; the first delay duration and the second delay duration are summed to obtain the engine system shutdown delay duration when the fuel is cut off and the engine is driven by the electric motor. This helps to completely expel the exhaust gas in the intake system and greatly reduce the exhaust gas in the engine cylinder, thus effectively reducing the impact of exhaust gas on the next start-up performance; in addition, since the engine is driven by the electric motor during the delay operation, the engine does not consume fuel, so the delayed shutdown process does not lead to an increase in fuel consumption, making it fuel-efficient.

[0230] Based on the same inventive concept, this disclosure also provides an engine system shutdown delay determination system. Figure 6 This is a structural block diagram of an engine system shutdown delay determination system provided in an embodiment of this disclosure. (See diagram below.) Figure 6As shown, the engine system shutdown delay determination system is configured to implement the engine system shutdown delay determination method provided in the previous embodiment. The engine system shutdown delay determination system includes: a first acquisition module, a second acquisition module, a determination module, a third acquisition module, and a calculation module.

[0231] The first acquisition module is configured to, in response to an engine shutdown request command, acquire the actual EGR rate of the current engine system as the actual EGR rate value before shutdown, and acquire the exhaust gas length ratio in the first pipeline from the EGR valve to the throttle valve in the current engine system as the exhaust gas length ratio value before shutdown.

[0232] The second acquisition module obtains the time taken for the engine system to discharge all the exhaust gas in the first pipeline from the throttle valve under the turbocharged closed-loop working state, based on the actual EGR rate value before shutdown, the exhaust gas length ratio value before shutdown, and the pre-acquired real vehicle turbocharged closed-loop delay database. This time is used as the basic delay time. The real vehicle turbocharged closed-loop delay database records the reference time taken for the engine system to discharge all the exhaust gas in the first pipeline from the throttle valve under the turbocharged closed-loop working state, using multiple different EGR rate values ​​for delay operation, when the first pipeline corresponds to multiple different exhaust gas length ratio values.

[0233] The module is configured to determine the duration during which all exhaust gas in the first pipeline is discharged from the throttle valve when the engine system is in a state of fuel cut-off and the engine is driven to rotate by the electric motor, based on the basic delay duration, and use this duration as the first delay duration.

[0234] The third acquisition module is configured to acquire the flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder, as the second delay time.

[0235] The calculation module is configured to sum the first delay duration and the second delay duration to obtain the engine system shutdown delay duration.

[0236] In some embodiments, the engine system shutdown delay determination system further includes a fourth acquisition module, which is used to acquire a real vehicle boost closed-loop delay database.

[0237] For a detailed description of each of the above functional modules, please refer to the relevant content of the corresponding steps in the previous embodiments, which will not be repeated here.

[0238] Based on the same inventive concept, this disclosure also provides an engine system shutdown delay control system. Figure 7 This is a structural block diagram of an engine system shutdown delay control system provided in an embodiment of the present disclosure. Figure 7As shown, the engine system shutdown delay control system includes: an engine system shutdown delay determination system, a first control module, and a second control module.

[0239] The engine system shutdown delay determination system adopts the engine system shutdown delay determination system provided in the previous embodiment.

[0240] The first control module is configured to control the engine system to cut off fuel, close the EGR valve, fully open the mixing valve, and use the motor to drive the engine to rotate, maintaining the engine's current operating conditions and continuing to run for a shutdown delay period.

[0241] The second control module is configured to control the engine to shut down after the shutdown delay period ends.

[0242] Based on the same inventive concept, this disclosure also provides a vehicle, including an engine system shutdown delay control system, wherein the engine system shutdown delay control system adopts the engine system shutdown delay control system provided in the preceding embodiments.

[0243] Based on the same inventive concept, embodiments of the present invention also provide an electronic device. Figure 8 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Figure 8 As shown, an embodiment of the present invention provides an electronic device including: one or more processors 101, a memory 102, and one or more I / O interfaces 103. The memory 102 stores one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement any of the engine system shutdown delay determination methods or engine system shutdown delay control methods described in the above embodiments; the one or more I / O interfaces 103 are connected between the processor and the memory, configured to enable information interaction between the processor and the memory.

[0244] The processor 101 is a device with data processing capabilities, including but not limited to a central processing unit (CPU); the memory 102 is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (FLASH); the I / O interface (read / write interface) 103 is connected between the processor 101 and the memory 102, and can realize information interaction between the processor 101 and the memory 102, including but not limited to a data bus (Bus).

[0245] In some embodiments, the processor 101, memory 102, and I / O interface 103 are interconnected via bus 104, and thus connected to other components of the computing device.

[0246] In some embodiments, the one or more processors 101 include a field-programmable gate array.

[0247] This invention also provides a computer-readable medium. The computer-readable medium stores a computer program, which, when executed by a processor, implements the steps of any of the engine system shutdown delay determination methods or engine system shutdown delay control methods described in the above embodiments. The computer-readable storage medium may be a volatile or non-volatile computer-readable storage medium.

[0248] This invention also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code. When the computer-readable code is run in the processor of an electronic device, the processor in the electronic device executes the above-described engine system shutdown delay determination method or engine system shutdown delay control method.

[0249] Those skilled in the art will understand that all or some of the steps, systems, and apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software can be distributed on a computer-readable storage medium, which may include computer storage media (or non-transitory media) and communication media (or transient media).

[0250] As is known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable program instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), flash memory or other memory technologies, portable compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is known to those skilled in the art that communication media typically contain computer-readable program instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0251] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0252] The computer program instructions used to perform the operations of this invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of the invention.

[0253] The computer program product described herein can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0254] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0255] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0256] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0257] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0258] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A method for determining engine system shutdown delay, wherein, include: In response to the engine shutdown request command, the actual EGR rate of the current engine system is obtained as the actual EGR rate value before shutdown, and the exhaust gas length ratio in the first pipeline from the EGR valve to the throttle valve in the current engine system is obtained as the exhaust gas length ratio value before shutdown. Based on the actual EGR rate value before shutdown, the exhaust gas length ratio value before shutdown, and the pre-acquired real-vehicle turbocharged closed-loop delay database, the time required for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve under turbocharged closed-loop operation is obtained as the basic delay time; wherein, the real-vehicle turbocharged closed-loop delay database records the reference time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve under turbocharged closed-loop operation with multiple different EGR rate values ​​when the first pipeline corresponds to multiple different exhaust gas length ratio values ​​respectively; Based on the aforementioned basic delay duration, the duration during which the engine system, in a state of fuel cut-off and engine rotation driven by the motor, discharges all the exhaust gas in the first pipeline from the throttle valve is determined, and this duration is taken as the first delay duration. The flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder is obtained as the second delay time; The first delay duration and the second delay duration are summed to obtain the shutdown delay duration of the engine system when the fuel is cut off and the engine is driven to rotate by the motor.

2. The method for determining engine system shutdown delay according to claim 1, wherein, Based on the aforementioned basic delay duration, the step of determining the duration for which the engine system, under fuel cut-off and motor-driven engine rotation conditions, discharges all exhaust gas from the first pipeline through the throttle valve, and using this as the first delay duration, includes: It is determined whether the engine system is in a boost closed-loop operating state or not in a boost closed-loop operating state when the engine stop request command is received; When it is determined that the engine system is in a boost closed-loop operating state when the engine stop request command is received, the first delay duration is determined based on the following formula: ； in, The first delay duration, The base delay duration, The preset delay factor is used. ∈(1,1.2]; If it is determined that the engine system was not in the boost closed-loop operating state when the engine stop request command was received, then the engine speed at the time the engine stop request command was received is obtained. Engine coolant temperature Atmospheric pressure Throttle inlet pressure Throttle outlet pressure The first delay duration is determined based on the following formula: ； in, To determine the throttle body inlet and outlet pressure ratio and engine speed The first adjustment coefficient is obtained by looking up the correspondence between the two parameters and the first preset calibration table. To determine based on engine coolant temperature Atmospheric pressure The second adjustment coefficient is obtained by looking up the second preset calibration correspondence table. The first preset calibration correspondence table records multiple different combinations of throttle inlet and outlet pressure ratios and engine speeds, as well as their corresponding adjustment coefficients; The second preset calibration correspondence table records multiple different combinations of engine water temperature and atmospheric pressure and their corresponding adjustment coefficients.

3. The method for determining engine system shutdown delay according to claim 1 or 2, wherein, Also includes: Obtain the real vehicle turbocharger closed-loop delay database, specifically including: A test result database is obtained, which records the test duration of the engine system operating under the boost closed-loop working state, with the EGR valve closed and the mixing valve fully open, using an engine bench test system to simulate and test the first pipeline under various preset exhaust gas length ratios, and the engine system operating under the boost closed-loop working state using the initial EGR rate values ​​corresponding to various preset categories of EGR rates to discharge all exhaust gas from the first pipeline from the throttle valve. During actual vehicle operation, the values ​​of various preset categories of EGR rates of the engine system are acquired in real time according to preset sampling rules. The test result database is updated according to the values ​​of various different EGR rates acquired at each sampling time to obtain the actual vehicle boosting closed-loop delay database.

4. The method for determining engine system shutdown delay according to claim 3, wherein, During actual vehicle operation, the steps of acquiring real-time values ​​of various preset categories of EGR rates of the engine system according to preset sampling rules, and updating the test result database based on the values ​​of various different EGR rates acquired at each sampling time to obtain the actual vehicle boosting closed-loop delay database include: Based on the corresponding initial EGR rate values ​​in ascending order, all the preset category EGR rates are sorted to obtain a preset category EGR rate sorting sequence. An EGR rate value array corresponding to the preset category EGR rate sorting sequence is then initialized. The EGR rate value array records the reference values ​​corresponding to each preset category EGR rate according to the preset category EGR rate sorting sequence. When the EGR rate value array is initialized, the reference values ​​corresponding to each preset category EGR rate are the corresponding initial EGR rate values. Based on the test result database, multiple delay duration arrays are initialized and generated, each corresponding to a different preset exhaust gas length ratio. Each delay duration array records the reference duration for which the engine system, under the corresponding preset exhaust gas length ratio, uses the reference value of each preset category EGR rate to delay operation in order to discharge all exhaust gas in the first pipeline from the throttle valve. The delay duration array also records the reference duration corresponding to each preset category EGR rate in a sorted sequence according to the preset category EGR rate. When initializing the delay duration array, the reference duration corresponding to each preset category EGR rate is the corresponding test duration recorded in the test result database. During actual vehicle operation, in response to the arrival of the acquisition time, the current value of each preset category EGR rate at the corresponding time is obtained, and the current value of each preset category EGR rate is compared with the EGR rate value array. Based on the comparison results, the EGR rate value array and the delay duration array are updated to obtain the actual vehicle boosting closed-loop delay database at the corresponding time.

5. The method for determining engine system shutdown delay according to claim 4, wherein, The number of preset category EGR rates in the preset category EGR rate sorting sequence is n; The number of reference values ​​in the EGR rate value array is n, and the i-th reference value A in the EGR rate value array is... i It corresponds to the i-th preset category EGR rate in the preset category EGR rate sorting sequence; The number of reference durations in each of the aforementioned delay duration arrays is n, and the i-th reference duration B in the delay duration array is... i It corresponds to the i-th preset category EGR rate in the preset category EGR rate sorting sequence; i∈[1,n] and is a positive integer; In response to the arrival of the acquisition time, the steps of obtaining the current value of the EGR rate of each preset category at the corresponding time, comparing the current value of the EGR rate of each preset category with the EGR rate value array, and updating the EGR rate value array and the delay duration array according to the comparison results include: In response to the arrival of the data acquisition time, the corresponding preset EGR rate lower limit endpoint value A0 and preset EGR rate upper limit endpoint value A0 are configured for the current EGR rate value array. n+1 And, respectively configure the corresponding preset duration lower limit endpoint value B0 and preset duration upper limit endpoint value B for each of the current delay duration arrays. n+1 ; Obtain the current value of the EGR rate for each preset category at the corresponding time, where the current value of the EGR rate for the i-th preset category is denoted as Q. i ; Initialize i = 1; Based on the current EGR rate value array, determine the current value range corresponding to the i-th preset category EGR rate [A]. i-1 A i+1 ]; The current value Q of the EGR rate of the i-th preset category. i Compare with the corresponding value range [A] i-1 A i+1 Compare them; If we compare Q i ∈[A i-1 A i+1 If i > n, then the EGR rate value array and each of the delay duration arrays are not adjusted, and the size of i and n is further compared. If the comparison shows i < n, then i is incremented by 1, and the comparison range corresponding to the current EGR rate of the i-th preset category is determined again based on the current EGR rate value array. i-1 A i+1 The steps; If i=n, ​​it means that the initial adjustment process is over, and further adjustments are made to each of the delay duration arrays based on the current EGR rate value array and the preset transition coefficient. If we compare Q i [A i-1 A i+1 ], then according to Q i The EGR rate value array is adjusted accordingly, and the delay duration arrays are adjusted based on the adjustment of the EGR rate value array, until Q... i The value range corresponding to the i-th preset category EGR rate determined by the adjusted EGR rate value array is [A]. i-1 A i+1 ]Inside.

6. The method for determining engine system shutdown delay according to claim 5, wherein, According to Q i The EGR rate value array is adjusted accordingly, and the delay duration arrays are adjusted based on the adjustment of the EGR rate value array, until Q... i The value range corresponding to the i-th preset category EGR rate determined by the adjusted EGR rate value array is [A]. i-1 A i+1 The steps within [the document] include: If we compare Q i <A i-1 Then, determine the value greater than Q from the current EGR rate value array. i And closest to Q i A reference value, denoted as m, is inserted at the position preceding the reference value originally located at position m in the EGR rate value array, where Q is inserted. i Then, the reference value at position n+1 in the EGR rate value array is deleted to adjust the EGR rate value array; simultaneously, based on the interpolation algorithm, an interpolation value is inserted at the position preceding the reference duration at position m in each of the delay duration arrays. i The corresponding reference durations are used to shift the positions of the reference durations originally located at positions m to n in each of the delay duration arrays one position to the right, and then the reference duration at position n+1 in each of the delay duration arrays is deleted to adjust each of the delay duration arrays; after the adjustment of the EGR rate value array and each of the delay duration arrays is completed, the value comparison range corresponding to the current preset category EGR rate is determined again based on the current EGR rate value array [A]. i-1 A i+1 The steps; If we compare Q i >A i-1 Then, from the current EGR rate value array, determine the value less than Q. i And closest to Q i A reference value, denoted as m, is inserted at the position following the reference value originally located at position m in the EGR rate value array, where Q is inserted. i Then, the reference value at the first position in the EGR rate value array is deleted to adjust the EGR rate value array; simultaneously, based on the interpolation algorithm, an interpolation value is inserted at the position after the reference duration at the m-th position in each of the delay duration arrays, interpolating the value with respect to Q. i The corresponding reference duration is then deleted, and the reference duration at the first position in each of the delay duration arrays is adjusted. After adjusting the EGR rate value array and each of the delay duration arrays, the value comparison range corresponding to the current preset category EGR rate is determined again based on the current EGR rate value array. i-1 A i+1 The steps are as follows.

7. The method for determining engine system shutdown delay according to claim 5, wherein, The steps for further adjusting each of the delay duration arrays based on the current EGR rate value array and the preset transition coefficient include: Each of the aforementioned delay duration arrays is used as a target delay duration array, and the target delay duration arrays are adjusted according to the following steps: Based on the reference values ​​in the EGR rate array and the reference durations in the target delay duration array obtained after the initial adjustment process, a first eigenvalue array and a second eigenvalue array are determined. The first eigenvalue array contains n sequentially arranged first eigenvalues, and the second eigenvalue array contains n sequentially arranged second eigenvalues. The i-th first eigenvalue in the first eigenvalue array is D... i1 and the i-th first eigenvalue D in the second eigenvalue array i2 Determined by the following formula: ； ； This represents the i-th reference value in the EGR rate array obtained after the initial adjustment process. This represents the i-th reference duration in the target delay duration array obtained after the initial adjustment process; Based on the first feature value array, the second feature value array, and the preset transition coefficient, the target delay duration array is further adjusted in the following manner: Among them, the first reference duration C1 in the further adjusted target delay duration array: C1=B1' The second reference duration C2 in the further adjusted target delay duration array: C2=max(B2',C1) The reference durations from the 3rd to the nth in the further adjusted target delay duration array are determined based on the following formula: ； Where i∈[2,n-1], C i This represents the i-th reference duration in the further adjusted target delay duration array. and There are two preset transition coefficients and , max() represents the function that takes the largest value.

8. The method for determining engine system shutdown delay according to claim 3, wherein, Several different preset EGR rate categories include: minimum EGR rate, actual EGR rate, target EGR rate, adjusted EGR rate, and maximum EGR rate.

9. A method for controlling engine system shutdown, wherein, include: In response to an engine shutdown request command, the engine system shutdown delay determination method as described in any one of claims 1 to 8 is used to determine the shutdown delay duration of the engine system in the state of fuel cut-off and engine rotation driven by an electric motor; The engine system controls the engine to cut off fuel, close the EGR valve, and fully open the mixing valve, while using an electric motor to drive the engine to rotate, maintaining the engine's current operating conditions and continuing operation for the specified shutdown delay time. After the specified shutdown delay period ends, the engine is controlled to shut down.

10. An engine system shutdown delay determination system, wherein, The engine system shutdown delay determination system is configured to implement the engine system shutdown delay determination method as described in any one of claims 1 to 9, and the engine system shutdown delay determination system includes: The first acquisition module is configured to, in response to an engine shutdown request command, acquire the value of the actual EGR rate of the current engine system as the actual EGR rate value before shutdown, and acquire the value of the proportion of exhaust gas length in the first pipeline from the EGR valve to the throttle valve in the current engine system as the proportion of exhaust gas length before shutdown. The second acquisition module is configured to acquire, based on the actual EGR rate value before shutdown, the exhaust gas length ratio value before shutdown, and a pre-acquired real-vehicle turbocharged closed-loop delay database, the time taken for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve while in turbocharged closed-loop operation, as the basic delay time; wherein, the real-vehicle turbocharged closed-loop delay database records the reference time for the engine system to discharge all exhaust gas in the first pipeline from the throttle valve using multiple different EGR rate values ​​when the first pipeline corresponds to multiple different exhaust gas length ratio values; The determination module is configured to determine, based on the basic delay duration, the duration during which the engine system, in a state of fuel cut-off and engine rotation driven by the motor, discharges all exhaust gas in the first pipeline from the throttle valve, and uses this duration as the first delay duration; The third acquisition module is configured to acquire the flow time of gas in the engine system from the throttle valve to the exhaust port of the engine cylinder, as the second delay time. The calculation module is configured to sum the first delay duration and the second delay duration to obtain the engine system shutdown delay duration.

11. An engine system shutdown delay control system, wherein, include: The engine system shutdown delay determination system adopts the engine system shutdown delay determination system as described in claim 10; The first control module is configured to control the engine fuel cut-off, EGR valve closure, and mixing valve full opening within the engine system, and to use a motor to drive the engine to rotate, maintaining the current operating condition of the engine and continuing to run for the shutdown delay period. The second control module is configured to control the engine to stop after the shutdown delay period ends.

12. A vehicle, wherein, include: The engine system shutdown delay control system as described in claim 11.

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