Method and apparatus for determining compression ignition event, engine, and storage medium

Abstract

A method and apparatus for determining a compression ignition event, an engine, and a storage medium. The method for determining a compression ignition event is applied to an engine and comprises: acquiring a plurality of crank angles obtained by sequentially rotating a crankshaft of the engine by preset angle increments (101); on the basis of the plurality of crank angles, determining combustion heat release data of a cylinder of the engine (102); performing data analysis on the combustion heat release data, and obtaining an analysis result (103); and when the analysis result exceeds a compression ignition threshold, determining that a compression ignition event has occurred in the cylinder (104). By means of the provided method for determining a compression ignition event, a compression ignition event in a cylinder of an engine can be accurately and rationally determined, which is helpful for subsequent effective control of ignition and compression ignition combustion in the cylinder of the engine.

Description

Compression ignition event determination method and device, engine, and storage medium Technical Field

[0001] The present invention relates to the field of engine technology, and in particular to a compression ignition event determination method and device, an engine, and a storage medium. Background Art

[0002] With the continuous progress and development of production and life, vehicles have become important tools for transportation, travel and other scenarios, and a good engine plays a vital role in the vehicle.

[0003] Currently, automotive engines primarily include gasoline engines and diesel engines. Gasoline engines use a spark plug to ignite gasoline, causing combustion within the cylinder to generate power. Diesel engines use a compression stroke to compress the fuel-air mixture, causing compression ignition within the cylinder to generate power.

[0004] Diesel engines lack a spark plug structure to promote ignition, which leads to oxygen deprivation in the engine and the production of toxic gases, causing environmental pollution. Gasoline engines also have high fuel consumption and poor economy. Therefore, the development of spark-ignition compression ignition (CICI) gasoline engines is a key research direction in the development of passenger car engines. CICI gasoline engines primarily combine spark plug ignition technology with compression stroke compression ignition and lean burn technology to achieve in-cylinder CICI combustion, significantly improving combustion efficiency.

[0005] In a spark-ignition compression-ignition gasoline engine, how to accurately determine whether compression ignition has occurred and to control the subsequent engine's spark-ignition compression-ignition combustion through the compression ignition event has become a difficult problem that needs to be solved and overcome.

[0006] Summary of the Invention

[0007] To overcome the problems existing in related technologies, the present disclosure provides a compression ignition event determination method and device, an engine, and a storage medium. The compression ignition event determination method proposed in this disclosure can accurately and reasonably determine compression ignition events within an engine cylinder, facilitating subsequent effective control of combustion within the engine cylinder.

[0008] The technical solution of the embodiment of the present disclosure is implemented as follows:

[0009] In a first aspect of an embodiment of the present disclosure, a method for determining a compression ignition event is provided, which is applied to an engine. The method includes:

[0010] Obtaining a plurality of crankshaft angles obtained by sequentially rotating the crankshaft of the engine by preset angle increments;

[0011] determining combustion heat release data of a cylinder of the engine based on a plurality of the crankshaft angles;

[0012] performing data analysis on the combustion heat release data to obtain analysis results;

[0013] When the analysis result exceeds a compression ignition threshold, it is determined that a compression ignition event occurs in the cylinder.

[0014] In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis result includes a curve change value; performing data analysis on the combustion heat release data to obtain the analysis result includes:

[0015] determining a preset crankshaft angle interval corresponding to the cylinder;

[0016] Based on the preset crankshaft angle interval, data analysis is performed on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval.

[0017] In some embodiments, the curve change value includes a maximum value of a curve value of the combustion heat release rate curve within the preset crankshaft angle interval and an extreme value of curvature change of the combustion heat release rate curve within the preset crankshaft angle interval; performing data analysis on the combustion heat release rate curve of the cylinder based on the preset crankshaft angle interval to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval includes:

[0018] Analyzing and sorting curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain a maximum value of the curve value;

[0019] and / or,

[0020] The curve value of the combustion heat release rate curve within the preset crankshaft angle range is analyzed and calculated to obtain the extreme value of the curvature change.

[0021] In some embodiments, analyzing and calculating the curve value of the combustion heat release rate curve within the preset crankshaft angle range to obtain the curvature change extreme value includes:

[0022] determining a difference between the curve values ​​of the combustion heat release rate curve corresponding to two adjacent crankshaft angles among a plurality of the crankshaft angles within the preset crankshaft angle interval;

[0023] determining a minimum ratio among a plurality of ratios between a plurality of the difference values ​​and the preset angle increment;

[0024] The absolute value of the minimum ratio is taken as the extreme value of the curvature change.

[0025] In some embodiments, the compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; when the analysis result exceeds the compression ignition threshold, determining that a compression ignition event occurs in the cylinder includes:

[0026] When the maximum value of the curve value exceeds the first compression ignition threshold, and / or the extreme value of the curvature change exceeds the second compression ignition threshold, it is determined that the compression ignition event occurs in the cylinder.

[0027] In some embodiments, determining the preset crankshaft angle interval corresponding to the cylinder includes:

[0028] Determine a calibrated crankshaft angle corresponding to the cylinder; wherein the calibrated crankshaft angle is used to represent the crankshaft angle corresponding to the piston of the cylinder reaching the compression top dead center position;

[0029] determining a first angle interval based on the calibrated crankshaft angle and a first preset number of crankshaft angles corresponding to the preset angle increments subtracted sequentially from the calibrated crankshaft angle;

[0030] determining a second angle interval based on the calibrated crankshaft angle and a second preset number of crankshaft angles corresponding to the calibrated crankshaft angle being increased sequentially by the preset angle increment;

[0031] The preset crank angle interval is determined based on the first angle interval and the second angle interval.

[0032] In some embodiments, determining combustion heat release data of the cylinders of the engine based on a plurality of crankshaft angles includes:

[0033] determining cylinder pressure data and cylinder volume corresponding to each of the plurality of crankshaft angles;

[0034] A combustion heat release rate curve of a cylinder of the engine is determined according to the cylinder pressure data and the cylinder volume corresponding to each crankshaft angle.

[0035] In some embodiments, determining a combustion heat release rate curve of a cylinder of the engine based on the cylinder pressure data and the cylinder volume corresponding to each crankshaft angle includes:

[0036] determining an i-th crankshaft angle degree among the plurality of crankshaft angle degrees, wherein i is an integer;

[0037] determining a cylinder pressure difference between the cylinder pressure data corresponding to the (i+1)th crankshaft angle and the cylinder pressure data corresponding to the (i-1)th crankshaft angle;

[0038] determining a volume difference between the cylinder volume corresponding to the (i+1)th crankshaft angle and the cylinder volume corresponding to the (i-1)th crankshaft angle;

[0039] A combustion heat release rate curve of the cylinder is determined based on the product of the volume difference and the cylinder pressure data corresponding to the i-th crank angle and the product of the cylinder pressure difference and the cylinder volume corresponding to the i-th crank angle.

[0040] In some embodiments, the cylinder includes a plurality of cylinders; when the analysis result exceeds a compression ignition threshold, determining that a compression ignition event occurs in the cylinder includes:

[0041] When the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the plurality of cylinders exceeds the compression ignition threshold, it is determined that the compression ignition event occurs in the cylinder.

[0042] In some embodiments, the method further comprises:

[0043] In a current working cycle, when the compression ignition event occurs in the cylinder, a first signal is generated; the first signal is used to indicate that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event;

[0044] When the compression ignition event does not occur in the cylinder, a second signal is generated, wherein the second signal is used to indicate that in a next working cycle, the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event.

[0045] According to a second aspect of the present disclosure, a compression ignition event determination device is provided, the device comprising:

[0046] An acquisition module is configured to acquire a plurality of crankshaft rotation angles obtained by sequentially rotating the crankshaft of the engine by preset angle increments;

[0047] a determination module configured to determine combustion heat release data of a cylinder of the engine based on a plurality of the crankshaft angles;

[0048] an analysis module configured to perform data analysis on the combustion heat release data to obtain analysis results;

[0049] The determination module is configured to determine that a compression ignition event occurs in the cylinder when the analysis result exceeds a compression ignition threshold.

[0050] In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis result includes a curve change value;

[0051] The analysis module is further configured to determine a preset crankshaft angle interval corresponding to the cylinder; based on the preset crankshaft angle interval, perform data analysis on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval.

[0052] In some embodiments, the curve change value includes a maximum value of a curve value of the combustion heat release rate curve within the preset crankshaft angle interval and an extreme value of a curvature change of the combustion heat release rate curve within the preset crankshaft angle interval;

[0053] The analysis module is further configured to analyze and sort the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the maximum value of the curve value; and / or analyze and calculate the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the extreme value of the curvature change.

[0054] In some embodiments, the analysis module is further configured to determine the difference between the curve values ​​of the combustion heat release rate curve corresponding to two adjacent crankshaft angles among the multiple crankshaft angles within the preset crankshaft angle range; determine the minimum ratio among the multiple ratios between the multiple differences and the preset angle increments; and use the absolute value of the minimum ratio as the extreme value of the curvature change.

[0055] In some embodiments, the compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; the determination module is further configured to determine that the compression ignition event occurs in the cylinder when the maximum value of the curve value exceeds the first compression ignition threshold and / or the extreme value of the curvature change exceeds the second compression ignition threshold.

[0056] In some embodiments, it is characterized in that the analysis module is further configured to determine a calibrated crankshaft angle corresponding to the cylinder; wherein the calibrated crankshaft angle is used to characterize the crankshaft angle corresponding to the piston of the cylinder reaching the compression top dead center position; based on the calibrated crankshaft angle and the calibrated crankshaft angle, a first preset number of crankshaft angles corresponding to the preset angle increment are subtracted in sequence to determine a first angle interval; based on the calibrated crankshaft angle and the calibrated crankshaft angle, a second preset number of crankshaft angles corresponding to the preset angle increment are added in sequence to determine a second angle interval; based on the first angle interval and the second angle interval, the preset crankshaft angle interval is determined.

[0057] In some embodiments, the determination module is further configured to determine the cylinder pressure data and cylinder volume corresponding to each of the multiple crankshaft angles; and determine the combustion heat release rate curve of the cylinder of the engine based on the cylinder pressure data and cylinder volume corresponding to each of the crankshaft angles.

[0058] In some embodiments, the determination module is further configured to determine the i-th crankshaft angle among the multiple crankshaft angles, where i is an integer; determine the cylinder pressure difference between the cylinder pressure data corresponding to the i+1-th crankshaft angle and the cylinder pressure data corresponding to the i-1-th crankshaft angle; determine the volume difference between the cylinder volume corresponding to the i+1-th crankshaft angle and the cylinder volume corresponding to the i-1-th crankshaft angle; and determine the combustion heat release rate curve of the cylinder based on the product of the volume difference and the cylinder pressure data corresponding to the i-th crankshaft angle, and the product of the cylinder pressure difference and the cylinder volume corresponding to the i-th crankshaft angle.

[0059] In some embodiments, the cylinder includes a plurality of cylinders; the determination module is further configured to determine that the compression ignition event occurs in the cylinder when the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the plurality of cylinders exceeds the compression ignition threshold.

[0060] In some embodiments, the device further includes: a signal generating module configured to generate a first signal when the compression ignition event occurs in the cylinder within a current working cycle; the first signal is used to indicate that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event; when the compression ignition event does not occur in the cylinder, generate a second signal, the second signal being used to indicate that within the next working cycle, the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event.

[0061] According to a third aspect of the present disclosure, an engine is provided, comprising:

[0062] a memory for storing executable instructions;

[0063] The processor is configured to implement the compression ignition event determination method proposed in the first aspect of the present disclosure when executing the executable instructions stored in the memory.

[0064] According to a fourth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, which stores executable instructions for implementing the compression ignition event determination method proposed in the first aspect of the present disclosure when executed by a processor.

[0065] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0066] By using the compression ignition event determination method proposed in the embodiment of the present disclosure, data analysis is performed on the combustion heat release data determined by the crankshaft angle of the engine's cyclic rotation, and the compression ignition event in the engine cylinder is determined based on the relationship between the analysis result and the compression ignition threshold value; in this way, the determination method proposed in the present disclosure is simple, and can quickly, accurately and reasonably determine the compression ignition event in the cylinder, and accurately locate the position and crankshaft angle where the compression ignition event occurs; it helps to subsequently effectively control the ignition compression ignition combustion in the engine cylinder, and further improves the engine combustion efficiency compared to blindly controlling the ignition without knowing the engine combustion state. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] FIG1 is a first flow chart of a method for determining a compression ignition event according to an exemplary embodiment;

[0068] FIG2 is a second flow chart of a method for determining a compression ignition event according to an exemplary embodiment;

[0069] FIG3 is a third flow chart of a method for determining a compression ignition event according to an exemplary embodiment;

[0070] FIG4 is a diagram showing a test analysis of in-cylinder combustion data according to an exemplary embodiment;

[0071] FIG5 is a schematic block diagram of the structure of an engine according to an exemplary embodiment. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting the present disclosure. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0073] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0074] In the following description, the terms "first\second\third" are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the art of the present disclosure. The terms used herein are only for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure.

[0076] Referring to FIG1 , FIG1 is a flow chart illustrating a compression ignition event determination method according to an exemplary embodiment. As shown in FIG1 , the compression ignition event determination method proposed in the present disclosure is applied to an engine. The compression ignition event determination method can be implemented through steps 101 to 104:

[0077] Step 101: Acquire a plurality of crankshaft angles obtained by sequentially rotating the crankshaft of the engine by preset angle increments;

[0078] Step 102: determining combustion heat release data of the cylinders of the engine based on the plurality of crankshaft angles;

[0079] Step 103: Analyze the combustion heat release data to obtain analysis results;

[0080] Step 104: When the analysis result exceeds a compression ignition threshold, it is determined that a compression ignition event occurs in the cylinder.

[0081] It should be noted that the compression ignition event determination method proposed in the present disclosure is applied in an engine, specifically, in a spark-ignition compression ignition gasoline engine.

[0082] Here, a spark-ignition compression ignition (SCI) gasoline engine utilizes a novel combustion method that combines the ignition and compression ignition processes. This requires the simultaneous placement of a fuel injector and a spark plug in the center of the SCI combustion chamber. During one operating stroke (operating cycle) of a SCI gasoline engine, the fuel injector is controlled to perform two injections and the spark plug is controlled to perform one ignition. During the intake stroke of a SCI gasoline engine, the piston moves toward compression bottom dead center (BDC), and the engine draws in air. Near BDC, a control module, such as an electronic control unit (ECU), controls the fuel injector to deliver a first injection of fuel into the cylinder. This first injection is entirely contained within the cylinder, resulting in a low fuel concentration. During the compression stroke of a SCI gasoline engine, the piston moves toward compression top dead center (TDC). When the piston reaches near TDC, the ECU controls the fuel injector to deliver a second injection of fuel into the center recess at the top of the piston. This second injection is entirely contained within the center recess at the top of the piston, resulting in a high fuel concentration. The ECU controls the injector to complete the second injection and controls the spark plug ignition, igniting the second injection amount in the center pit on the top of the piston to form a fire core. The fire core increases the temperature and pressure in the cylinder, promoting the ignition and compression combustion of the thin oil volume of the first compressed injection when it reaches the top dead center of compression, completing the entire ignition and compression combustion process.

[0083] During their research into spark-ignition compression-ignition gasoline engines, the applicant discovered that different combustion conditions can occur within a gasoline engine when the ignition angle controlling the spark plug ignition is different. Identifying the occurrence of an effective compression-ignition event and determining the ignition angle at which compression ignition occurs can help the engine accurately complete the spark-ignition compression-ignition combustion process in subsequent operating cycles. Therefore, through the embodiments proposed in this disclosure, by analyzing the combustion heat release data of the engine cylinders, it is possible to accurately and reasonably determine the compression-ignition event within the cylinder of a spark-ignition compression-ignition gasoline engine, facilitating the subsequent effective control of the ignition angle to achieve spark-ignition compression-ignition combustion of the gasoline within the cylinder.

[0084] Here, in step 101, the crankshaft is a rotating component in the engine that receives the force from the crank connecting rod and converts it into torque output through the crankshaft to drive the piston in the engine cylinder to work effectively. Here, the engine crankshaft rotates once 360 ​​degrees, and within one working cycle of the cylinder, the engine crankshaft rotates at least twice. Here, the crankshaft angle is the rotation angle of the crankshaft. Usually, the crankshaft angle corresponding to the position where the piston moves to the compression top dead center is set as the calibrated crankshaft angle. Here, the calibrated crankshaft angle is defined as 0 degrees.

[0085] During the working cycle of the cylinder, multiple crankshaft angles obtained by the engine crankshaft rotating in a preset rotation direction in sequence at preset angle increments are determined, and cylinder characteristic data corresponding to each crankshaft angle is obtained; here, the cylinder characteristic data includes but is not limited to cylinder pressure, piston position, cylinder volume, etc.

[0086] It should be noted that the preset rotation direction can be clockwise or counterclockwise; the preset angle increment is pre-set and corresponds to the engine torque variable. Specifically, the disclosed embodiment controls the torque based on the engine control module (e.g., ECU) to sequentially change the torque variable to achieve the crankshaft rotating in the preset rotation direction by the preset angle increments.

[0087] Exemplarily, the preset angle increment may be 1 degree.

[0088] In actual implementation, the crankshaft angle is used as a reference to monitor multiple crankshaft angles obtained every time the engine crankshaft rotates 1 degree, and cylinder characteristic data such as cylinder pressure, piston position, and cylinder volume corresponding to each crankshaft angle are obtained.

[0089] In step 102 , based on cylinder characteristic data corresponding to each crankshaft angle among a plurality of crankshaft angles, combustion heat release data of the cylinder is determined according to the cylinder characteristic data.

[0090] Here, the combustion heat release data is used to reflect the combustion state of the gasoline and lean mixture in the cylinder of the engine. In this disclosure, the combustion heat release data includes but is not limited to the combustion heat release, the heat release rate curve derived from the combustion heat release, the cylinder pressure curve, the engine work energy, etc.

[0091] In step 103, the combustion heat release data is analyzed, calculated, and sorted to obtain an analysis result representing the combustion state in the cylinder.

[0092] In the embodiment of the present disclosure, when the combustion heat release data includes combustion heat release, the combustion heat release corresponding to each crankshaft angle can be sorted to obtain an analysis result, and the analysis result at this time includes the average value of the combustion heat release; when the combustion heat release data includes a cylinder pressure curve, the cylinder pressure curve is differentiated to obtain an analysis result, and the analysis result at this time includes the cylinder pressure rise rate; when the combustion heat release data includes the engine work energy, the work energy is subjected to data analysis based on the cylinder volume to obtain an analysis result, and the analysis result at this time includes the mean effective pressure; here, the mean effective pressure refers to the effective work generated per unit cylinder working volume.

[0093] In step 104 , when the analysis result exceeds the compression ignition threshold, it can be determined that a compression ignition event occurs in the cylinder.

[0094] Here, the compression ignition event in the cylinder of the spark-ignition compression ignition gasoline engine in the present disclosure is manifested as: through the ignition process of the spark plug and the compression ignition process of the up and down movement of the piston, the gasoline and the lean mixture in the cylinder are burned, presenting a spark-ignition compression ignition combustion state.

[0095] In combination with the analysis results shown in the above-mentioned embodiments of the present disclosure, when the analysis results include the average value of combustion heat release, the compression ignition threshold includes a heat threshold. When the average value of combustion heat release exceeds the heat threshold, it is determined that a compression ignition event has occurred in the cylinder; when the average value of combustion heat release does not exceed the heat threshold, it is determined that no compression ignition event has occurred in the cylinder; when the analysis results include the cylinder pressure rise rate, the compression ignition threshold includes a cylinder pressure curve threshold. When the maximum value of the cylinder pressure rise rate exceeds the cylinder pressure curve threshold, it is determined that a compression ignition event has occurred in the cylinder; when the maximum value of the cylinder pressure rise rate does not exceed the cylinder pressure curve threshold, it is determined that no compression ignition event has occurred in the cylinder; when the analysis results include the mean effective pressure, the compression ignition threshold includes an effective pressure threshold. When the mean effective pressure exceeds the effective pressure threshold, it is determined that a compression ignition event has occurred in the cylinder; when the mean effective pressure does not exceed the effective pressure threshold, it is determined that no compression ignition event has occurred in the cylinder.

[0096] It should be noted that the analysis results in the embodiment of the present disclosure include any one of the above parameters and may also include other parameters. In actual implementation, if any one parameter or multiple optional parameters exceed the corresponding compression ignition threshold, it can be determined that a compression ignition event has occurred in the cylinder.

[0097] In some embodiments, the compression ignition event determination method proposed in the present disclosure further includes:

[0098] In a current working cycle, when the compression ignition event occurs in the cylinder, a first signal is generated; the first signal is used to indicate that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event;

[0099] When the compression ignition event does not occur in the cylinder, a second signal is generated, wherein the second signal is used to indicate that in a next working cycle, the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event.

[0100] Here, the cylinder can output a signal corresponding to the state determination result. For example, the first signal is output as a high-level digital signal, indicating that a compression ignition event has occurred in the cylinder, and that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event in a subsequent working cycle. The second signal is output as a low-level digital signal, indicating that a compression ignition event has not occurred in the cylinder, and that the ignition angle needs to be adjusted in a subsequent working cycle to control the occurrence of the compression ignition event in the cylinder.

[0101] For example, the first signal is transmitted in the form of a signal 1 (true), and the second signal is transmitted in the form of a signal 0 (false).

[0102] In the embodiment of the present disclosure, after obtaining the first signal generated by the cylinder, the preset ignition angle and preset combustion state parameters corresponding to the cylinder are obtained based on the first signal, and the preset ignition angle is written into the ignition angle three-dimensional table (MAP1), and the preset combustion state parameters are written into the combustion heat release control three-dimensional table (MAP2).

[0103] Here, the preset ignition angle is the current ignition angle of the cylinder; the preset combustion state parameters include the crankshaft angle corresponding to the parameter value of the combustion heat release rate reaching 50%, and the engine cylinder is controlled to perform ignition compression ignition combustion in subsequent working cycles through MAP1 and MAP2.

[0104] For example, the cylinder is ignited using a preset ignition angle output by MAP1, and the ignition angle is corrected based on a preset combustion state parameter output by MAP2.

[0105] In the embodiment of the present disclosure, the first signal and the second signal are used to output the determination result of the compression ignition event through a digital signal, so that the engine can effectively identify the determination result, so as to facilitate the subsequent precise control of the engine combustion state.

[0106] The compression ignition event determination method proposed in the embodiments of the present disclosure analyzes combustion heat release data determined by the crankshaft angle during engine cyclic rotation, and determines compression ignition events within the engine cylinder based on the relationship between the analysis results and the compression ignition threshold. As such, the determination method proposed in the present disclosure is simple and can quickly, accurately, and reasonably determine compression ignition events within the cylinder, precisely locating the location and crankshaft angle at which the compression ignition event occurred. This facilitates subsequent effective control of compression ignition combustion within the engine cylinder, further improving engine combustion efficiency compared to blindly controlling ignition without knowing the engine's combustion state.

[0107] In some examples, the combustion heat release data presented in the present disclosure may include a combustion heat release rate curve.

[0108] In some embodiments, the step 102 of determining combustion heat release data of the cylinders of the engine based on the plurality of crankshaft angles includes:

[0109] determining cylinder pressure data and cylinder volume corresponding to each of the plurality of crankshaft angles;

[0110] A combustion heat release rate curve of a cylinder of the engine is determined according to the cylinder pressure data and the cylinder volume corresponding to each crankshaft angle.

[0111] Here, the combustion heat release rate curve is generated based on the combustion heat release rates of the cylinders at multiple crankshaft angles. Specifically, the combustion heat release rate is determined using cylinder characteristic data (including cylinder pressure and in-cylinder volume) corresponding to each crankshaft angle θ. The combustion heat release rate curve is then generated based on the combustion heat release rates at multiple crankshaft angles θ. Here, the combustion heat release rate (dQ / dθ) represents the change in the instantaneous heat release energy Q corresponding to each cylinder at each crankshaft angle θ, as a function of the crankshaft angle θ.

[0112] The disclosed embodiment determines the curve change value of the combustion heat release rate through the cylinder pressure data and the cylinder volume corresponding to the crankshaft angle, and can concretely represent the combustion heat release data in the cylinder, so as to effectively determine the occurrence of a compression ignition event in the cylinder through the data analysis results of the curve change value.

[0113] In some embodiments, the above embodiments of the present disclosure provide that: determining a combustion heat release rate curve of a cylinder of the engine according to the cylinder pressure data and the cylinder volume corresponding to each crankshaft angle includes:

[0114] determining an i-th crankshaft angle degree among the plurality of crankshaft angle degrees, wherein i is an integer;

[0115] determining a cylinder pressure difference between the cylinder pressure data corresponding to the (i+1)th crankshaft angle and the cylinder pressure data corresponding to the (i-1)th crankshaft angle;

[0116] determining a volume difference between the cylinder volume corresponding to the (i+1)th crankshaft angle and the cylinder volume corresponding to the (i-1)th crankshaft angle;

[0117] A combustion heat release rate curve of the cylinder is determined based on the product of the volume difference and the cylinder pressure data corresponding to the i-th crank angle and the product of the cylinder pressure difference and the cylinder volume corresponding to the i-th crank angle.

[0118] Here, first, a calibrated crankshaft angle (the crankshaft angle corresponding to the cylinder's piston reaching compression top dead center) is defined as 0 degrees. During crankshaft rotation, the corresponding crankshaft angle for each preset angle increment of the cylinder is determined. It should be noted that the preset angle increments proposed in this disclosure are integers, and the angular intervals between i and i-1, and between i and i+1, are the same as the preset angle increments. Here, the preset angle increment is 1 degree.

[0119] In the present disclosure, the cylinder pressure data (Pi) corresponding to the i-th crankshaft angle can be obtained by the cylinder pressure signal output by the cylinder pressure sensor; the cylinder volume (Vi) corresponding to the i-th crankshaft angle can be obtained by the following formulas (1) and (2):

[0120] Here, Vc is the volume of the combustion chamber on the top surface of the piston in the cylinder, B is the cylinder diameter; Si is the current position of the piston in the piston; l is the length of the crank connecting rod, a is the crank radius, and here, i∈[-180, 180].

[0121] In the disclosed embodiment, based on the cylinder pressure data and cylinder volume corresponding to the i-th crankshaft angle, the i-1-th crankshaft angle, and the i+1-th crankshaft angle, respectively, the combustion heat release rate (dQ / di, i.e., Qi) can be obtained by formula (3):

[0122] Here, Pi is the cylinder pressure data corresponding to the i-th crankshaft angle, and Vi is the cylinder volume corresponding to the i-th crankshaft angle; Pi-1 is the cylinder pressure data corresponding to the i-1-th crankshaft angle, and Vi-1 is the cylinder volume corresponding to the i-1-th crankshaft angle; Pi+1 is the cylinder pressure data corresponding to the i+1-th crankshaft angle, and Vi+1 is the cylinder volume corresponding to the i+1-th crankshaft angle; k is the thermodynamic polynomial, a preset parameter. In the disclosed embodiment, k for a spark-ignition compression ignition gasoline engine can be set to 1.35, where i∈[-180, 180].

[0123] The disclosed embodiment effectively determines the change in combustion heat release when the crankshaft angle changes, i.e., the combustion heat release rate, through the cylinder pressure data and cylinder volume corresponding to the i-th crankshaft angle, the i-1th crankshaft angle, and the i+1th crankshaft angle, and obtains a combustion heat release rate curve, which concretely represents the combustion heat release data in the cylinder.

[0124] Referring to FIG. 2 , FIG. 2 is a second flow chart illustrating a method for determining a compression ignition event according to an exemplary embodiment. In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis result includes a curve change value. In conjunction with FIG. 2 , the analysis of the combustion heat release data in step 103 to obtain the analysis result can be performed by the following steps:

[0125] Step 1031: Determine a preset crankshaft angle interval corresponding to the cylinder;

[0126] Step 1032: Based on the preset crankshaft angle interval, perform data analysis on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval.

[0127] Here, the analysis result includes a curve change value, and step 104 can be implemented by step 1041:

[0128] Step 1041: When the curve change value exceeds the compression ignition threshold, it is determined that a compression ignition event occurs in the cylinder.

[0129] In step 1031, the preset angle interval can be pre-set or dynamically adjusted. In the present disclosure, the preset crankshaft angle interval can be the crankshaft angle interval corresponding to the piston moving from the compression top dead center position to the compression bottom dead center position. The preset crankshaft angle interval can also be the crankshaft angle interval between the piston's corresponding crankshaft angle corresponding to the spark plug ignition position (i.e., the ignition angle) and the piston's corresponding crankshaft angle corresponding to the piston moving to the compression top dead center and then from the compression top dead center to the specified position.

[0130] It should be noted that in the present disclosure, the engine cylinders fully burn, release heat, and perform work externally within a preset crank angle range.

[0131] In some embodiments, determining the preset crankshaft angle interval corresponding to the cylinder in step 1031 may be implemented in the following manner:

[0132] Determine a calibrated crankshaft angle corresponding to the cylinder; wherein the calibrated crankshaft angle is used to represent the crankshaft angle corresponding to the piston of the cylinder reaching the compression top dead center position;

[0133] determining a first angle interval based on the calibrated crankshaft angle and a first preset number of crankshaft angles corresponding to the preset angle increments subtracted sequentially from the calibrated crankshaft angle;

[0134] determining a second angle interval based on the calibrated crankshaft angle and a second preset number of crankshaft angles corresponding to the calibrated crankshaft angle being increased sequentially by the preset angle increment;

[0135] The preset crank angle interval is determined based on the first angle interval and the second angle interval.

[0136] In the present disclosure, the calibrated crankshaft angle (the crankshaft angle corresponding to the cylinder piston reaching the compression top dead center position) is defined as 0 degrees; the first preset number and the second preset number can be pre-set, and the first preset number and the second preset number can be the same or different.

[0137] Exemplarily, determining the first angle interval based on the calibrated crankshaft angle minus a first preset number of crankshaft angles corresponding to preset angle increments can be implemented as follows: determining the first angle interval to be (-20, 0] based on the crankshaft angle obtained by subtracting 20 1-degree increments from 0 degree; determining the second angle interval based on the calibrated crankshaft angle plus a second preset number of crankshaft angles corresponding to preset angle increments can be implemented as determining the second angle interval to be [0, 70] based on the crankshaft angle obtained by adding 70 1-degree increments from 0 degree.

[0138] Here, determining the preset crank angle interval based on the first angle interval and the second angle interval includes: using the set of the first angle interval and the second angle interval as the preset crank angle interval. Exemplarily, the preset crank angle interval is (-20, 70).

[0139] The disclosed embodiment can locate the area where the engine cylinder is fully combusted by obtaining a preset crankshaft angle interval, further making the analysis of the combustion heat release data more representative and improving the accuracy of determining the occurrence of a compression ignition event.

[0140] In step 1032, data analysis is performed on the combustion heat release rate curve of the cylinder based on the preset crank angle interval to obtain a curve change value of the combustion heat release rate curve within the preset crank angle interval. This can be implemented by sorting the curve values ​​corresponding to all crank angles of the combustion heat release rate curve within the preset crank angle interval (i.e., the combustion heat release rates corresponding to all crank angles) to determine the minimum curve value of the combustion heat release rate curve. Accordingly, in step 1041, when the minimum curve value exceeds a compression ignition threshold (e.g., a minimum compression ignition threshold), it is determined that a compression ignition event has occurred in the cylinder.

[0141] By determining the curve change value of the combustion heat release rate, the combustion heat release data in the cylinder can be concretely represented, so that the occurrence of the compression ignition event in the cylinder can be determined by analyzing the curve change value.

[0142] In some embodiments, the curve change value includes a maximum value of a curve value of the combustion heat release rate curve within the preset crankshaft angle interval and an extreme value of curvature change of the combustion heat release rate curve within the preset crankshaft angle interval; performing data analysis on the combustion heat release rate curve of the cylinder based on the preset crankshaft angle interval to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval includes:

[0143] Analyzing and sorting curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain a maximum value of the curve value;

[0144] and / or,

[0145] The curve value of the combustion heat release rate curve within the preset crankshaft angle range is analyzed and calculated to obtain the extreme value of the curvature change.

[0146] In the embodiment of the present disclosure, the curve values ​​corresponding to all crankshaft angles within the preset crankshaft angle range of the combustion heat release rate curve, i.e., the combustion heat release rates (dQ / dθ) corresponding to all crankshaft angles, are sorted to determine the maximum value of the curve value. And / or, the combustion heat release rate curve is differentiated within the preset crankshaft angle range to obtain a curvature change value (2dQ / dθ) of the combustion heat release rate (dQ / dθ) between two adjacent crankshaft angles (i.e., separated by a preset angle increment), and a minimum value of the curvature change value (2dQ / dθ) within the preset crankshaft angle range is determined, and the absolute value of the minimum value is used as the extreme value of the curvature change.

[0147] Here, the curvature change curve formed by the curvature change values ​​can reflect the degree of change in the combustion heat release rate at predetermined angle increments. When the degree of change in the combustion heat release rate approaches the degree of change in the compression ignition combustion heat release rate, the effective occurrence of a compression ignition event in the cylinder can be determined. In the present disclosure, the degree of change in the compression ignition combustion heat release rate can be characterized by a compression ignition threshold.

[0148] In some embodiments, analyzing and calculating the curve value of the combustion heat release rate curve within the preset crankshaft angle range to obtain the curvature change extreme value includes:

[0149] determining a difference between the curve values ​​of the combustion heat release rate curve corresponding to two adjacent crankshaft angles among a plurality of the crankshaft angles within the preset crankshaft angle interval;

[0150] determining a minimum ratio among a plurality of ratios between a plurality of the difference values ​​and the preset angle increment;

[0151] The absolute values ​​of the multiple minimum ratios are taken as the extreme values ​​of the curvature change.

[0152] For example, in combination with the above disclosure, the curvature change value (2dQ / di) corresponding to the i-th crankshaft angle within the preset crankshaft angle interval is obtained by the following formula (4):

[0153] It should be noted that Q i -Q i-1 It is expressed as the difference between the curve values ​​of the combustion heat release rate curve corresponding to two adjacent crankshaft angles; the curve values ​​of the combustion heat release rate curve, namely the combustion heat release rates Qi and Qi-1, can be obtained by formula (3); [i-(i-1)] is expressed as a preset angle increment, where the preset angle increment is 1 degree, i is an integer, and i is within the preset crankshaft angle range.

[0154] In determining the minimum ratio among all ratios obtained according to formula (4) in the present disclosure Then, calculate the absolute value of the minimum ratio And take the absolute value as the extreme value of curvature change (that is, take the minimum value of curvature change).

[0155] The disclosed embodiment obtains the maximum value of the curve value of the combustion heat release rate curve within a preset crankshaft angle range and the extreme value of the curvature change of the combustion heat release rate curve within the preset crankshaft angle range through data analysis, which can concretely represent the combustion heat release state in the cylinder, so that the occurrence of a compression ignition event can be effectively determined by the maximum value of the curve value and / or the extreme value of the curvature change.

[0156] In some embodiments, the compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; when the analysis result exceeds the compression ignition threshold, determining that a compression ignition event occurs in the cylinder includes:

[0157] When the maximum value of the curve value exceeds the first compression ignition threshold, and / or the extreme value of the curvature change exceeds the second compression ignition threshold, it is determined that a compression ignition event occurs in the cylinder.

[0158] Here, the first compression ignition threshold comprises the maximum value of a compression ignition heat release rate curve when the cylinder is in a compression ignition operating condition, and is used to indicate efficient compression ignition combustion occurring within the cylinder. Here, the first compression ignition threshold may be the maximum value of the combustion heat release rate curve within a working cycle in which a compression ignition event occurs on the cylinder, or may be the average of the maximum values ​​of the combustion heat release rate curve within multiple working cycles in which compression ignition events occur.

[0159] The second compression ignition threshold is represented by the extreme curvature change value of the compression ignition combustion heat release rate curve when the cylinder is under compression ignition conditions. The extreme curvature change value is the minimum curvature change value, and is used to indicate the location corresponding to the maximum change in the compression ignition combustion heat release rate. The second compression ignition threshold can be the minimum curvature change value of the compression ignition combustion heat release rate curve within a working cycle in which a compression ignition event occurs on the cylinder, or can be the average of the minimum curvature change values ​​of the combustion heat release rate curve within multiple working cycles in which compression ignition events occur.

[0160] In the present disclosure, the first compression ignition threshold and the second compression ignition threshold are different. For example, the first compression ignition threshold limit1 can be set between 70% and 90%, and the second compression ignition threshold limit2 can be set between 3 and 5.

[0161] In actual implementation, in some examples, when the maximum value of the curve value When the first compression ignition threshold value limit1 is exceeded, it can be determined that a compression ignition event occurs in the cylinder; in other examples, when the curvature changes to an extreme value When the second compression ignition threshold value limit2 is exceeded, it can be determined that a compression ignition event occurs in the cylinder; in some other examples, when the maximum value of the curve value Exceeds the first compression ignition threshold limit1, and the curvature changes to the extreme value When the second compression ignition threshold value limit2 is exceeded, it can be determined that a compression ignition event occurs in the cylinder.

[0162] Here, the occurrence of a compression ignition event can be quickly determined based on the relationship between the maximum value of the curve value and the first compression ignition threshold, which helps to speed up the subsequent engine ignition control process; the occurrence of a compression ignition event can be more accurately determined based on the relationship between the extreme value of the curvature change and the second compression ignition threshold, which helps to increase the accuracy of the subsequent engine ignition control; and, by combining the relationship between the maximum value of the curve value and the first compression ignition threshold and the relationship between the extreme value of the curvature change and the second compression ignition threshold, it can be more efficiently and accurately determined whether a compression ignition event has occurred in the cylinder, thereby improving the diversity and reliability of determining the occurrence of a compression ignition event in the cylinder.

[0163] In some embodiments, the cylinder includes a plurality of cylinders; when the analysis result exceeds a compression ignition threshold, determining that a compression ignition event occurs in the cylinder includes:

[0164] When the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the plurality of cylinders exceeds the compression ignition threshold, it is determined that a compression ignition event occurs in the cylinder.

[0165] Here, the spark-ignition compression-ignition gasoline engine proposed in the present disclosure may have multiple cylinders. Here, the multiple cylinders may be three, four, or five, etc., and the present disclosure does not impose any limitation on this.

[0166] It should be noted that combustion in each cylinder is independent; therefore, the engine control module processes combustion heat release data, analyzes the results, and determines the occurrence of a compression ignition event independently for each cylinder. The compression ignition threshold for each cylinder is also determined based on the combustion heat release data from the cylinder's historical operating cycles during which compression ignition events occurred.

[0167] The disclosed embodiment independently analyzes and judges multiple cylinders of the engine, thereby facilitating subsequent individual ignition control of each cylinder of the engine. Compared with unified ignition control, it takes into account the differences between each cylinder and further improves the combustion efficiency of the engine.

[0168] In the following, a specific application embodiment of the compression ignition event determination method proposed in the present disclosure is described in combination with the above embodiments of the present disclosure.

[0169] Here, the compression ignition event determination method can be implemented in a spark-ignition compression ignition gasoline engine. By installing a pressure sensor in each cylinder of the spark-ignition compression ignition gasoline engine, a test method design and cylinder pressure data processing are used to determine whether a compression ignition event has occurred. Referring to Figure 3, Figure 3 is a schematic flow chart illustrating a compression ignition event determination method according to an exemplary embodiment. As shown in Figure 3, the compression ignition event determination method proposed in this disclosure can be implemented through the following steps:

[0170] Step 301, measuring the combustion heat release rate of the cylinder based on the crankshaft angle;

[0171] Using the crankshaft angle as the reference axis, the in-cylinder pressure of each cylinder at every 1-degree engine rotation, the current crankshaft angle, and the cylinder volume are monitored. This data is processed to determine the combustion heat release rate (dQ / dθ) for each cylinder. The combustion heat release rate (dQ / dθ) represents the change in the instantaneous heat release energy Q of the cylinder at each crankshaft angle θ, based on the crankshaft angle θ.

[0172] Here, the combustion heat release rate at the crankshaft angle (dQ / dθ), Qi, can be obtained by formula (3):

[0173] It should be noted that Pi is the cylinder pressure data corresponding to the i-th crankshaft angle; Vi is the cylinder volume corresponding to the i-th crankshaft angle; Pi-1 is the cylinder pressure data corresponding to the i-1-th crankshaft angle, and Vi-1 is the cylinder volume corresponding to the i-1-th crankshaft angle; Pi+1 is the cylinder pressure data corresponding to the i+1-th crankshaft angle, and Vi+1 is the cylinder volume corresponding to the i+1-th crankshaft angle; k is the thermodynamic polynomial, a preset parameter. In the disclosed embodiment, k for a spark-ignition compression ignition gasoline engine can be set to 1.35, where i∈[-180, 180].

[0174] Step 302, obtaining a combustion heat release rate curve corresponding to the combustion heat release rate;

[0175] See Figure 4, which shows an analysis chart of in-cylinder combustion data testing according to an exemplary embodiment. As shown in Figure 4, the abscissa of the coordinate system represents crankshaft angle, and the ordinate represents crankshaft angle CA corresponding to the combustion heat release rate. The solid line in Figure 4 represents the combustion heat release rate curve corresponding to the combustion heat release rate.

[0176] Step 303 : Derivative processing is performed on the combustion heat release rate curve based on the crankshaft angle, and an extreme value of the curvature change of the combustion heat release rate curve is determined within a preset crankshaft angle range.

[0177] Here, the combustion heat release rate curve is differentiated based on the crankshaft angle to obtain the curvature change value (2dQ / dθ) of the combustion heat release rate (dQ / dθ) between two adjacent crankshaft angles (i.e., separated by a preset angle increment). The minimum value of the multiple curvature change values ​​(2dQ / dθ) within the preset crankshaft angle interval is determined, and the absolute value of the minimum value is used as the extreme value of the curvature change.

[0178] In combination with the above disclosure, the curvature change value (2dQ / di) corresponding to the i-th crankshaft angle within the preset crankshaft angle interval is obtained by the following formula (4):

[0179] Here, i is an integer, and i is within the preset crankshaft angle range.

[0180] In determining the minimum ratio of all ratios obtained according to formula (4) in this disclosure Then, calculate the absolute value of the minimum ratio And the absolute value is taken as the extreme value of the curvature change.

[0181] In conjunction with Figure 4, the dashed line in Figure 4 represents the curvature change curve formed by the curvature change value of the combustion heat release rate curve. Here, 0 degrees on the abscissa represents the crankshaft angle corresponding to the piston reaching the compression top dead center position in the cylinder; the preset crankshaft range is between the starting angle Angel_start (e.g., -20 degrees) and the ending angle Angel_end (e.g., 70 degrees).

[0182] As shown in FIG4 , when the curvature change of the combustion heat release rate curve is at its maximum, the corresponding curvature change curve has a curvature change extreme value. By comparing the curvature change extreme value and the second compression ignition threshold, it is possible to determine the proximity between the position at which the curvature change of the combustion heat release rate curve is at its maximum and the position at which the compression ignition combustion heat release rate is at its maximum, thereby determining whether a compression ignition event has occurred in the cylinder in the current cycle.

[0183] Step 304, obtaining a second compression ignition threshold;

[0184] Here, the second compression ignition threshold value limt2 is obtained. The second compression ignition threshold value limit2 can be set between 3 and 5.

[0185] Step 305 , determining whether the curvature change extreme value is greater than the second compression ignition threshold; if so, executing step 306 , otherwise executing step 307 .

[0186] Step 306 , determining whether a compression ignition event occurs in the cylinder and generating a first signal;

[0187] Here, the first signal is transmitted in the form of a digital signal 1 (true).

[0188] Step 307 : Determine whether a compression ignition event has not occurred in the cylinder, and generate a second signal.

[0189] Here, the second signal is transmitted in the form of a digital signal 0 (false).

[0190] Step 306 and step 307 can be implemented as follows:

[0191] Here, when When the judgment result is transmitted as signal 1 (true), , the judgment result is transmitted as signal 0 (false).

[0192] In the present disclosure, a spark-ignition compression-ignition gasoline engine includes multiple cylinders, each of which is independently subjected to data acquisition, signal processing, and compression-ignition event determination, and the compression-ignition event determination result for each cycle is transmitted in the form of 1 (true) or 0 (false); after determining that a compression-ignition event has occurred, the ignition angle corresponding to the cylinder is determined so that the controller can perform ignition control on the cylinder to promote compression-ignition in subsequent working cycles.

[0193] The compression ignition event determination method proposed in the present disclosure can accurately and reasonably determine the compression ignition event in the engine cylinder, which helps to effectively control the subsequent ignition compression ignition combustion in the engine cylinder.

[0194] Next, an engine device for implementing the above-mentioned compression ignition event determination method provided by an embodiment of the present disclosure is described. Referring to FIG5 , FIG5 is a schematic block diagram of the structure of an engine according to an exemplary embodiment. As shown in FIG5 , the engine 500 includes: at least one processor 501 and a memory 502. The various components in the engine 500 are coupled together through a bus system 503. It can be understood that the bus system 503 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 503 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, various buses are labeled as bus systems 503 in FIG5 .

[0195] The processor 501 can be an integrated circuit chip with signal processing capabilities, such as a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., where the general-purpose processor can be a microprocessor or any conventional processor, etc.

[0196] The memory 502 may be removable, non-removable, or a combination thereof. An exemplary hardware device may be a solid-state memory. The memory 502 may optionally include one or more storage devices that are physically remote from the processor 501.

[0197] The memory 502 includes volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), and the volatile memory may be a random access memory (RAM). The memory 502 described in the embodiments of the present disclosure is intended to include any suitable type of memory.

[0198] In some embodiments, the memory 502 can store data to support various operations. Examples of such data include programs, modules, and data structures, or subsets or supersets thereof. In the disclosed embodiment, the memory 502 stores an operating system 5021 and a compression ignition event determination device 5022. Specifically:

[0199] The operating system 5021 includes system programs configured to handle various basic system services and perform hardware-related tasks, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic businesses and process hardware-based tasks.

[0200] In some embodiments, the compression ignition event determination device provided in embodiments of the present disclosure can be implemented using software. FIG5 shows a compression ignition event determination device 5022 stored in memory 502 . This device can be software in the form of a program or plug-in, and includes the following software modules: an acquisition module 50221 , a determination module 50222 , an analysis module 50223 , a determination module 50224 , and a signal generation module 50225 . These modules are logically linked and can be arbitrarily combined or further separated based on the functions they implement. The functions of each module are described below.

[0201] In other embodiments, the compression ignition event determination device provided in the embodiments of the present disclosure may be implemented in hardware. As an example, the compression ignition event determination device provided in the embodiments of the present disclosure may be a processor in the form of a hardware decoding processor, which is programmed to execute the compression ignition event determination method provided in the embodiments of the present disclosure. For example, the processor in the form of a hardware decoding processor may be one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), or other electronic components.

[0202] The following further describes an exemplary structure of the compression ignition event determination device 5022 provided in an embodiment of the present disclosure as a software module. In some embodiments, as shown in FIG5 , the software module stored in the compression ignition event determination device 5022 in the memory 502 may include:

[0203] An acquisition module 50221 is configured to acquire a plurality of crankshaft rotation angles obtained by sequentially rotating the crankshaft of the engine by preset angle increments;

[0204] A determination module 50222 is configured to determine combustion heat release data of a cylinder of the engine based on a plurality of crankshaft angles;

[0205] The analysis module 50223 is configured to perform data analysis on the combustion heat release data to obtain analysis results;

[0206] The determination module 50224 is configured to determine that a compression ignition event occurs in the cylinder when the analysis result exceeds a compression ignition threshold.

[0207] In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis result includes a curve change value.

[0208] The analysis module 50223 is further configured to determine a preset crankshaft angle interval corresponding to the cylinder; based on the preset crankshaft angle interval, perform data analysis on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval.

[0209] In some embodiments, the curve change value includes a maximum curve value of the combustion heat release rate curve within the preset crankshaft angle interval and an extreme curvature change value of the combustion heat release rate curve within the preset crankshaft angle interval.

[0210] The analysis module 50223 is further configured to analyze and sort out the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the maximum value of the curve value; and / or to analyze and calculate the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the extreme value of the curvature change.

[0211] In some embodiments, the analysis module 50223 is further configured to determine the difference between the curve values ​​of the combustion heat release rate curve corresponding to two adjacent crankshaft angles among the multiple crankshaft angles within the preset crankshaft angle range; determine the minimum ratio among the multiple ratios between the multiple differences and the preset angle increments; and use the absolute value of the minimum ratio as the extreme value of the curvature change.

[0212] In some embodiments, the compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; the determination module 50224 is further configured to determine that the compression ignition event occurs in the cylinder when the maximum value of the curve value exceeds the first compression ignition threshold and / or the extreme value of the curvature change exceeds the second compression ignition threshold.

[0213] In some embodiments, the analysis module 50223 is further configured to determine a calibrated crankshaft angle corresponding to the cylinder; wherein the calibrated crankshaft angle is used to characterize the crankshaft angle corresponding to the piston of the cylinder reaching the compression top dead center position; based on the calibrated crankshaft angle and the calibrated crankshaft angle minus the first preset number of crankshaft angles corresponding to the preset angle increment, a first angle interval is determined; based on the calibrated crankshaft angle and the calibrated crankshaft angle, the second preset number of crankshaft angles corresponding to the preset angle increment is added in sequence to determine the second angle interval; based on the first angle interval and the second angle interval, the preset crankshaft angle interval is determined.

[0214] In some embodiments, the determination module 50222 is further configured to determine the cylinder pressure data and cylinder volume corresponding to each of the multiple crankshaft angles; and determine the combustion heat release rate curve of the cylinder of the engine based on the cylinder pressure data and cylinder volume corresponding to each of the crankshaft angles.

[0215] In some embodiments, the determination module 50222 is further configured to determine the i-th crankshaft angle among the multiple crankshaft angles, where i is an integer; determine the cylinder pressure difference between the cylinder pressure data corresponding to the i+1-th crankshaft angle and the cylinder pressure data corresponding to the i-1-th crankshaft angle; determine the volume difference between the cylinder volume corresponding to the i+1-th crankshaft angle and the cylinder volume corresponding to the i-1-th crankshaft angle; and determine the combustion heat release rate curve of the cylinder based on the product of the volume difference and the cylinder pressure data corresponding to the i-th crankshaft angle, and the product of the cylinder pressure difference and the cylinder volume corresponding to the i-th crankshaft angle.

[0216] In some embodiments, the cylinder includes a plurality of cylinders; the determination module 50224 is further configured to determine that the compression ignition event occurs in the cylinder when the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the plurality of cylinders exceeds the compression ignition threshold.

[0217] In some embodiments, the device further includes: a signal generating module 50225, configured to generate a first signal when the compression ignition event occurs in the cylinder within the current working cycle; the first signal is used to indicate that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event; when the compression ignition event does not occur in the cylinder, a second signal is generated, and the second signal is used to indicate that within the next working cycle, the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event.

[0218] It should be noted that the description of the apparatus of the embodiment of the present disclosure is similar to the description of the above-mentioned method embodiment, and has similar beneficial effects as the method embodiment, so it will not be repeated.

[0219] The present disclosure provides a computer program product or program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the compression ignition event determination method described above in the present disclosure.

[0220] An embodiment of the present disclosure provides a computer-readable storage medium storing executable instructions, wherein the executable instructions are stored. When the executable instructions are executed by a processor, the processor will execute the compression ignition event determination method provided by the embodiment of the present disclosure.

[0221] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface storage, optical disk, or CD-ROM; or various devices including one or any combination of the above memories.

[0222] In some embodiments, executable instructions may be in the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0223] As an example, executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file that stores other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinating files (e.g., files storing one or more modules, subroutines, or code portions).

[0224] By way of example, executable instructions may be deployed to be executed on one computing device, or on multiple computing devices at one site, or on multiple computing devices distributed across multiple sites and interconnected by a communication network.

[0225] In summary, the embodiments of the present disclosure can accurately and reasonably determine the compression ignition event in the engine cylinder, which helps to effectively control the subsequent ignition compression ignition combustion in the cylinder of the gasoline engine.

[0226] The above description is merely an embodiment of the present disclosure and is not intended to limit the scope of protection of the present disclosure. Any modifications, equivalent replacements, and improvements made within the spirit and scope of the present disclosure are included in the scope of protection of the present disclosure.

Claims

1. A compression ignition event determination method, characterized in that: Applied in an engine, the method comprises: Acquire a plurality of crankshaft rotation angles obtained by sequentially rotating the crankshaft of the engine by preset angle increments; determining combustion heat release data of a cylinder of the engine based on a plurality of the crankshaft angles; Performing data analysis on the combustion heat release data to obtain analysis results; When the analysis result exceeds a compression ignition threshold, it is determined that a compression ignition event occurs in the cylinder.

2. The method according to claim 1, characterized in that The combustion heat release data includes a combustion heat release rate curve, and the analysis result includes a curve change value; the data analysis of the combustion heat release data to obtain the analysis result includes: Determining a preset crankshaft angle interval corresponding to the cylinder; Based on the preset crankshaft angle interval, data analysis is performed on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval.

3. The method according to claim 2, characterized in that The curve change value includes a maximum value of a curve value of the combustion heat release rate curve in the preset crankshaft angle interval and an extreme value of a curvature change of the combustion heat release rate curve in the preset crankshaft angle interval; based on the preset crankshaft angle interval, performing data analysis on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve in the preset crankshaft angle interval includes: Analyzing and sorting the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle interval to obtain the maximum value of the curve value; and / or, The curve value of the combustion heat release rate curve within the preset crankshaft angle interval is analyzed and calculated to obtain the extreme value of the curvature change.

4. The method according to claim 3, characterized in that The analyzing and calculating the curve value of the combustion heat release rate curve within the preset crankshaft angle interval to obtain the curvature change extreme value includes: Determine two adjacent crankshaft angles among the plurality of crankshaft angles within the preset crankshaft angle interval. The difference between the curve values ​​of the combustion heat release rate curve corresponding to the angle; Determine a minimum ratio among a plurality of ratios between a plurality of the difference values ​​and the preset angle increment; The absolute value of the minimum ratio is taken as the extreme value of the curvature change.

5. The method according to claim 3, characterized in that: The compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; when the analysis result exceeds the compression ignition threshold, determining that a compression ignition event occurs in the cylinder includes: When the maximum value of the curve value exceeds the first compression ignition threshold, and / or the extreme value of the curvature change exceeds the second compression ignition threshold, it is determined that the compression ignition event occurs in the cylinder.

6. The method according to claim 2, characterized in that The determining of the preset crankshaft angle interval corresponding to the cylinder includes: Determine a calibrated crankshaft angle corresponding to the cylinder; wherein the calibrated crankshaft angle is used to characterize the crankshaft angle corresponding to the piston of the cylinder reaching the compression top dead center position; Determining a first angle interval based on the calibrated crankshaft angle and a first preset number of crankshaft angles corresponding to the preset angle increments sequentially subtracted from the calibrated crankshaft angle; Determining a second angle interval based on the calibrated crankshaft angle and a second preset number of crankshaft angles corresponding to the preset angle increments sequentially increased by the calibrated crankshaft angle; The preset crankshaft angle interval is determined based on the first angle interval and the second angle interval.

7. The method according to any one of claims 2 to 6, characterized in that The step of determining combustion heat release data of the cylinders of the engine based on the plurality of crankshaft angles comprises: Determine cylinder pressure data and cylinder volume corresponding to each of the crankshaft rotation angles among the plurality of crankshaft rotation angles; A combustion heat release rate curve of a cylinder of the engine is determined according to the cylinder pressure data and the cylinder volume corresponding to each crankshaft angle.

8. The method according to claim 7, characterized in that The step of determining the combustion heat release rate curve of the cylinder of the engine according to the cylinder pressure data and the cylinder volume corresponding to each crankshaft angle comprises: determining an i-th crankshaft angle among the plurality of crankshaft angles, wherein i is an integer; Determine the cylinder pressure data corresponding to the i+1 degree crankshaft angle and the cylinder pressure data corresponding to the i-1 degree crankshaft angle The cylinder pressure difference between Determining a volume difference between the cylinder volume corresponding to the (i+1)th crankshaft angle and the cylinder volume corresponding to the (i-1)th crankshaft angle; A combustion heat release rate curve of the cylinder is determined based on the product of the volume difference value and the cylinder pressure data corresponding to the i-th crank angle and the product of the cylinder pressure difference value and the cylinder volume corresponding to the i-th crank angle.

9. The method according to any one of claims 1 to 6, characterized in that The cylinder includes a plurality of cylinders; when the analysis result exceeds a compression ignition threshold, determining that a compression ignition event occurs in the cylinder includes: When the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the plurality of cylinders exceeds the compression ignition threshold, it is determined that the compression ignition event occurs in the cylinder.

10. The method according to any one of claims 1 to 6, characterized in that The method further comprises: In a current working cycle, when the compression ignition event occurs in the cylinder, a first signal is generated; the first signal is used to indicate that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event; When the compression ignition event does not occur in the cylinder, a second signal is generated, wherein the second signal is used to indicate that in a next working cycle, the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event.

11. A compression ignition event determination device, characterized in that: The device comprises: An acquisition module is configured to acquire a plurality of crankshaft rotation angles obtained by sequentially rotating a crankshaft of the engine by preset angle increments; a determination module configured to determine combustion heat release data of a cylinder of the engine based on a plurality of the crankshaft angles; An analysis module is configured to perform data analysis on the combustion heat release data to obtain analysis results; The determination module is configured to determine that a compression ignition event occurs in the cylinder when the analysis result exceeds a compression ignition threshold.

12. The device according to claim 11, characterized in that The combustion heat release data includes a combustion heat release rate curve, and the analysis result includes a curve change value; The analysis module is further configured to determine a preset crankshaft angle interval corresponding to the cylinder; based on the preset crankshaft angle interval, perform data analysis on the combustion heat release rate curve of the cylinder to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle interval.

13. The device according to claim 12, characterized in that The curve change value includes a maximum value of a curve value of the combustion heat release rate curve within the preset crankshaft angle interval and an extreme value of a curvature change of the combustion heat release rate curve within the preset crankshaft angle interval; The analysis module is further configured to analyze and sort the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle interval to obtain the maximum value of the curve value; and / or to analyze and calculate the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle interval to obtain the curvature change extreme value.

14. The device according to claim 13, characterized in that The analysis module is further configured to determine the difference between the curve values ​​of the combustion heat release rate curve corresponding to two adjacent crankshaft angles among the multiple crankshaft angles within the preset crankshaft angle range; determine the minimum ratio among the multiple ratios between the multiple differences and the preset angle increments; and use the absolute value of the minimum ratio as the extreme value of the curvature change.

15. The device according to claim 13, characterized in that The compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; the determination module is further configured to determine that the compression ignition event occurs in the cylinder when the maximum value of the curve value exceeds the first compression ignition threshold and / or the extreme value of the curvature change exceeds the second compression ignition threshold.

16. The device according to claim 12, characterized in that The analysis module is further configured to determine a calibrated crankshaft angle corresponding to the cylinder; wherein the calibrated crankshaft angle is used to characterize the crankshaft angle corresponding to the position of the piston of the cylinder reaching the compression top dead center; based on the calibrated crankshaft angle and the calibrated crankshaft angle, a first preset number of crankshaft angles corresponding to the preset angle increment is sequentially subtracted to determine a first angle interval; based on the calibrated crankshaft angle and the calibrated crankshaft angle, a second preset number of crankshaft angles corresponding to the preset angle increment is sequentially added to determine a second angle interval; based on the first angle interval and the second angle interval, The preset crankshaft angle interval is determined.

17. The device according to any one of claims 12 to 16, characterized in that The determination module is further configured to determine the cylinder pressure data and cylinder volume corresponding to each of the multiple crankshaft angles; and determine the combustion heat release rate curve of the cylinder of the engine based on the cylinder pressure data and cylinder volume corresponding to each of the crankshaft angles.

18. The device according to claim 17, characterized in that The determination module is further configured to determine the i-th crankshaft angle among the multiple crankshaft angles, wherein i is an integer; determine the cylinder pressure difference between the cylinder pressure data corresponding to the i+1-th crankshaft angle and the cylinder pressure data corresponding to the i-1-th crankshaft angle; determine the volume difference between the cylinder volume corresponding to the i+1-th crankshaft angle and the cylinder volume corresponding to the i-1-th crankshaft angle; and determine the combustion heat release rate curve of the cylinder based on the product of the volume difference and the cylinder pressure data corresponding to the i-th crankshaft angle, and the product of the cylinder pressure difference and the cylinder volume corresponding to the i-th crankshaft angle.

19. The device according to any one of claims 11 to 16, characterized in that The cylinder comprises a plurality of; The determination module is further configured to determine that the compression ignition event occurs in the cylinder when the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the plurality of cylinders exceeds the compression ignition threshold.

20. The device according to any one of claims 11 to 16, characterized in that The device also includes: The signal generating module is configured to generate a first signal when the compression ignition event occurs in the cylinder within a current working cycle; the first signal is used to indicate that the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event; when the compression ignition event does not occur in the cylinder, generate a second signal, and the second signal is used to indicate that in the next working cycle, the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event.

21. An engine, characterized in that: include: a memory configured to store executable instructions; The processor is configured to execute the executable instructions stored in the memory to implement the claim The compression ignition event determination method according to any one of 1 to 10.

22. A computer-readable storage medium, characterized in that: The device stores executable instructions and is configured to implement the compression ignition event determination method according to any one of claims 1 to 10 when executed by a processor.

Images