A compression ignition event determination method and device, engine, and storage medium

Abstract

The disclosure provides a compression ignition event determination method and device, an engine and a storage medium. The compression ignition event determination method is applied to an engine, and the method comprises: obtaining a plurality of crank angles obtained by sequentially rotating a crankshaft of the engine by a preset angle increment; determining combustion heat release data of a cylinder of the engine based on the plurality of crank angles; performing data analysis on the combustion heat release data to obtain an analysis result; and determining that a compression ignition event occurs in the cylinder when the analysis result exceeds a compression ignition threshold. The compression ignition event determination method provided by the disclosure can accurately and reasonably determine the compression ignition event in the cylinder of the engine, which helps to effectively control the ignition compression combustion in the cylinder of the engine.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a method and apparatus for determining compression ignition events, an engine, and a storage medium. Background Technology

[0002] With the continuous progress and development of production and life, vehicles have become important tools for transportation and commuting, and a good engine plays a crucial role in the development of vehicles.

[0003] Currently, automotive engines mainly include gasoline engines and diesel engines. Gasoline engines use spark plugs to ignite gasoline, causing combustion in the cylinder to achieve power. Diesel engines use compression strokes to compress the mixture of fuel and air, causing compression combustion in the cylinder to achieve power.

[0004] Diesel engines, lacking spark plugs to promote ignition, suffer from oxygen deficiency, producing toxic gases and causing environmental pollution. Gasoline engines, on the other hand, have high fuel consumption and poor economy. Therefore, spark-compression ignition gasoline engines are an important research direction for the development of passenger car engines. Spark-compression ignition gasoline engines mainly combine spark plug ignition technology, compression stroke compression ignition technology, and lean combustion technology to achieve spark-compression ignition combustion in the cylinder, significantly improving combustion efficiency.

[0005] In spark-compression ignition gasoline engines, how to accurately determine whether compression ignition has occurred, so as to control the subsequent ignition and compression combustion of the engine based on the compression ignition event, has become a difficult problem that urgently needs to be solved and overcome. Summary of the Invention

[0006] To overcome the problems existing in related technologies, this disclosure provides a method and apparatus for determining compression ignition events, an engine, and a storage medium. The method for determining compression ignition events proposed in this disclosure can accurately and reasonably determine compression ignition events within the engine cylinder, which helps to effectively control the ignition and combustion of compression ignition within the engine cylinder.

[0007] The technical solution of this disclosure embodiment is implemented as follows:

[0008] A first aspect of this disclosure provides a method for determining compression ignition events, applied in an engine, the method comprising:

[0009] The crankshaft rotation angles of the engine are obtained by sequentially rotating the crankshaft by a preset angle increment;

[0010] The combustion heat release data of the engine cylinders are determined based on multiple crankshaft rotation angles;

[0011] The combustion heat release data were analyzed to obtain the analysis results;

[0012] When the analysis result exceeds the compression ignition threshold, it is determined that a compression ignition event has occurred in the cylinder.

[0013] In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis results include curve change values; the data analysis of the combustion heat release data to obtain analysis results includes:

[0014] Determine the preset crankshaft angle range corresponding to the cylinder;

[0015] Based on the preset crankshaft angle range, 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 range.

[0016] In some embodiments, the curve change value includes the maximum value of the combustion heat release rate curve within the 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; the step of performing data analysis on the combustion heat release rate curve of the cylinder based on the preset crankshaft angle range to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle range includes:

[0017] The maximum value of the combustion heat release rate curve within the preset crankshaft angle range is obtained by analyzing and organizing the curve values ​​of the curve.

[0018] And / or,

[0019] The extreme values ​​of the curvature change are obtained by analyzing and calculating the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range.

[0020] In some embodiments, the step of analyzing and calculating the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the extreme values ​​of the curvature change includes:

[0021] Determine the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft angles within the preset crankshaft angle range;

[0022] Determine the smallest ratio among a plurality of ratios between the plurality of differences and the preset angle increment;

[0023] The absolute value of the minimum ratio is taken as the extreme value of the curvature change.

[0024] In some embodiments, the compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; determining that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold includes:

[0025] When the maximum value of the curve exceeds the first compression ignition threshold, and / or the extreme value of the curvature change exceeds the second compression ignition threshold, the compression ignition event is determined to have occurred in the cylinder.

[0026] In some embodiments, determining the preset crankshaft angle range corresponding to the cylinder includes:

[0027] Determine the 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 top dead center position of the compression stroke;

[0028] The first angle range is determined based on the calibrated crankshaft angle and the first preset number of crankshaft angles corresponding to the preset angle increment, in turn, subtracted from the calibrated crankshaft angle.

[0029] Based on the calibrated crankshaft angle and the second preset number of crankshaft angles corresponding to the preset angle increment, the second angle range is determined;

[0030] Based on the first angle range and the second angle range, the preset crankshaft angle range is determined.

[0031] In some embodiments, determining the combustion heat release data of the engine cylinders based on a plurality of crankshaft angles includes:

[0032] Determine the cylinder pressure data and cylinder volume corresponding to each of the multiple crankshaft rotation angles;

[0033] Based on the cylinder pressure data and cylinder volume corresponding to each crankshaft rotation angle, the combustion heat release rate curve of the engine cylinder is determined.

[0034] In some embodiments, determining the combustion heat release rate curve of the engine cylinder based on the cylinder pressure data and cylinder volume corresponding to each crankshaft rotation angle includes:

[0035] Determine the i-th degree crankshaft angle from among the plurality of crankshaft angles, where i is an integer;

[0036] Determine the cylinder pressure difference between the cylinder pressure data corresponding to the (i+1)th degree crankshaft angle and the cylinder pressure data corresponding to the (i-1)th degree crankshaft angle;

[0037] Determine the volume difference between the cylinder internal volume corresponding to the (i+1)th degree crankshaft rotation angle and the cylinder internal volume corresponding to the (i-1)th degree crankshaft rotation angle;

[0038] The 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 degree crankshaft angle, and the product of the cylinder pressure difference and the cylinder internal volume corresponding to the i-th degree crankshaft angle.

[0039] In some embodiments, the cylinder includes multiple cylinders; determining that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold includes:

[0040] When the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the multiple cylinders exceeds the compression ignition threshold, it is determined that the compression ignition event has occurred in the cylinder.

[0041] In some embodiments, the method further includes:

[0042] During the 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.

[0043] When the compression ignition event does not occur in the cylinder, a second signal is generated, which indicates that the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event in the next working cycle.

[0044] A second aspect of this disclosure provides a compression ignition event determination device, the device comprising:

[0045] The acquisition module is configured to acquire multiple crankshaft angles obtained by sequentially rotating the engine's crankshaft by a preset angle increment;

[0046] The determination module is configured to determine the combustion heat release data of the engine cylinders based on multiple crankshaft angles;

[0047] The analysis module is configured to perform data analysis on the combustion heat release data and obtain analysis results;

[0048] The determination module is configured to determine that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold.

[0049] In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis results include curve change values;

[0050] The analysis module is further configured to determine a preset crankshaft angle range corresponding to the cylinder; and based on the preset crankshaft angle range, to 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 range.

[0051] In some embodiments, the curve change value includes the maximum value of the curve value of the combustion heat release rate curve within the 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;

[0052] The analysis module is further configured to analyze and organize 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.

[0053] In some embodiments, the analysis module is further configured to: determine the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft angles in a plurality of crankshaft angles within the preset crankshaft angle range; determine the minimum ratio among a plurality of ratios between the plurality of differences and the preset angle increment; and take the absolute value of the minimum ratio as the curvature change extreme value.

[0054] 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 has occurred 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.

[0055] In some embodiments, the analysis module is further configured to determine the 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 top dead center of compression; a first angle interval is determined based on the calibrated crankshaft angle and the calibrated crankshaft angle by successively subtracting a first preset number of crankshaft angles corresponding to the preset angle increment; a second angle interval is determined based on the calibrated crankshaft angle and the calibrated crankshaft angle by successively increasing a second preset number of crankshaft angles corresponding to the preset angle increment; and a preset crankshaft angle interval is determined based on the first angle interval and the second angle interval.

[0056] In some embodiments, the determining module is further configured to determine cylinder pressure data and cylinder volume corresponding to each of the plurality of crankshaft angles; and to determine the combustion heat release rate curve of the engine cylinder based on the cylinder pressure data and cylinder volume corresponding to each crankshaft angle.

[0057] In some embodiments, the determining module is further configured to: determine the i-th crankshaft angle among a plurality of 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 internal volume corresponding to the (i+1)-th crankshaft angle and the cylinder internal 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 internal volume corresponding to the i-th crankshaft angle.

[0058] In some embodiments, the cylinders include a plurality of cylinders; the determination module is further configured to determine that a compression ignition event has occurred 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.

[0059] In some embodiments, the apparatus further includes: a signal generation module configured to generate a first signal when the compression ignition event occurs in the cylinder during the current working cycle; the first signal being used to indicate that the current ignition angle corresponding to the cylinder is capable of controlling the occurrence of the compression ignition event; and generating a second signal when the compression ignition event does not occur in the cylinder, the second signal being used to indicate that the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event during the next working cycle.

[0060] A third aspect of this disclosure provides an engine, comprising:

[0061] Memory, used to store executable instructions;

[0062] The processor, when executing executable instructions stored in the memory, implements the compression ignition event determination method proposed in the first aspect of this disclosure.

[0063] A fourth aspect of this disclosure provides a computer-readable storage medium storing executable instructions for implementing the compression ignition event determination method proposed in the first aspect of this disclosure when executed by a processor.

[0064] The technical solutions provided in this disclosure may have the following beneficial effects:

[0065] The compression ignition event determination method proposed in this disclosure analyzes the combustion heat release data determined by the crankshaft angle during engine rotation, and determines the compression ignition event in the engine cylinder based on the relationship between the analysis results and the compression ignition threshold. Thus, the determination method proposed in this disclosure is simple, can quickly, accurately, and reasonably determine the compression ignition event in the cylinder, and accurately locate the location of the compression ignition event and the crankshaft angle. This helps to effectively control the engine cylinder to achieve compression ignition combustion, and further improves the engine combustion efficiency compared to blindly controlling ignition without knowing the engine combustion state. Attached Figure Description

[0066] Figure 1 This is a flowchart illustrating a compression ignition event determination method according to an exemplary embodiment. Figure 1 ;

[0067] Figure 2 This is a flowchart illustrating a compression ignition event determination method according to an exemplary embodiment. Figure 2 ;

[0068] Figure 3 This is a flowchart illustrating a compression ignition event determination method according to an exemplary embodiment. Figure 3 ;

[0069] Figure 4 This is a test analysis diagram of in-cylinder combustion data according to an exemplary embodiment;

[0070] Figure 5 This is a schematic block diagram of the engine structure according to an exemplary embodiment. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of this disclosure clearer, the disclosure will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this disclosure. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0072] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is 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.

[0073] In the following description, the terms “first, second, third” are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that “first, second, third” may be interchanged in a specific order or sequence where permitted, so that the embodiments of this disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to be limiting of this disclosure.

[0075] See Figure 1 , Figure 1 This is a flowchart illustrating a compression ignition event determination method according to an exemplary embodiment. Figure 1 ;like Figure 1 As shown, the compression ignition event determination method proposed in this disclosure is applied to an engine, and the compression ignition event determination method can be implemented through steps 101 to 104:

[0076] Step 101: Obtain multiple crankshaft rotation angles obtained by sequentially rotating the crankshaft of the engine by a preset angle increment;

[0077] Step 102: Determine the combustion heat release data of the engine cylinders based on multiple crankshaft rotation angles;

[0078] Step 103: Perform data analysis on the combustion heat release data to obtain the analysis results;

[0079] Step 104: When the analysis result exceeds the compression ignition threshold, it is determined that a compression ignition event has occurred in the cylinder.

[0080] It should be noted that the compression ignition event determination method proposed in this disclosure is applied to engines, specifically to spark-compression ignition gasoline engines.

[0081] Here, the spark-compression ignition (SCCI) gasoline engine features a novel combustion method that combines the ignition and compression ignition processes. This requires the simultaneous placement of the fuel injector and spark plug in the center of the SCCI combustion chamber. One working stroke (working cycle) of a SCCI gasoline engine controls the fuel injector to perform two fuel injections and the spark plug to perform one ignition. During the intake stroke of a SCCI gasoline engine, the piston moves towards bottom dead center (BDC) of the compression stroke, and the engine draws in air. Near BDC, the control module, such as the Electronic Control Unit (ECU), controls the fuel injector to perform the first fuel injection into the cylinder. The first injection quantity is contained within the cylinder, resulting in a lean fuel concentration. During the compression stroke of a SCCI gasoline engine, the piston moves towards top dead center (TDC). When the piston reaches near TDC, the ECU controls the fuel injector to perform a second fuel injection into the center recess of the piston crown. The second injection quantity is contained within the center recess of the piston crown, resulting in a high fuel concentration. The ECU controls the injector to complete the second injection and controls the spark plug to ignite the second injection in the center recess of the piston top, forming a flame core. The flame core causes the temperature and pressure inside the cylinder to rise, promoting the ignition and compression ignition of the lean fuel from the first injection when it reaches the top dead center of the compression stroke, thus completing the entire ignition and compression ignition process.

[0082] In exploring spark-compression ignition gasoline engines, the applicant discovered that different combustion conditions may occur within the gasoline engine when the ignition angle of the spark plug is controlled differently. Identifying the occurrence of a valid compression ignition event and determining the ignition angle at which compression ignition occurs can help the engine accurately complete the spark-compression ignition combustion process in subsequent working cycles. Therefore, through the embodiments proposed in this disclosure, analyzing the combustion heat release data of the engine cylinder can accurately and reasonably determine the compression ignition event within the cylinder of a spark-compression ignition gasoline engine, which helps to effectively control the ignition angle to achieve spark-compression ignition combustion of gasoline within the cylinder.

[0083] Here, in step 101, the crankshaft is a rotating component in the engine that bears the force transmitted from the crankshaft and connecting rod, converting it into torque and outputting it through the crankshaft to drive the pistons in the engine cylinders to work effectively. Here, one rotation of the engine crankshaft is 360 degrees, and within one working cycle of the cylinders, the engine crankshaft rotates at least twice. Here, the crankshaft angle is the rotational angle of the crankshaft. Typically, the crankshaft angle corresponding to the piston moving to the top dead center of the compression stroke is set as the calibrated crankshaft angle; here, the calibrated crankshaft angle is defined as 0 degrees.

[0084] Within the working cycle of the cylinder, multiple crankshaft rotation angles are determined by sequentially rotating the engine crankshaft along a preset rotation direction by a preset angle increment, and cylinder characteristic data corresponding to each crankshaft rotation angle is obtained; here, cylinder characteristic data includes, but is not limited to, cylinder pressure, piston position, cylinder volume, etc.

[0085] It should be noted that the preset rotation direction can be clockwise or counterclockwise; the preset angle increment is preset and corresponds to the engine torque variable; specifically, in this embodiment, the torque variable is changed sequentially based on the engine control module (such as ECU) to realize that the crankshaft rotates sequentially along the preset rotation direction by the preset angle increment.

[0086] For example, the preset angle increment can be 1 degree.

[0087] In actual implementation, the crankshaft rotation angle is used as a reference to monitor multiple crankshaft rotation angles obtained for each degree of crankshaft rotation of the engine, and to obtain cylinder characteristic data such as cylinder pressure, piston position, and cylinder volume corresponding to each crankshaft rotation angle.

[0088] In step 102, based on the cylinder characteristic data corresponding to each crankshaft angle among multiple crankshaft angles, the combustion heat release data of the cylinder is determined according to the cylinder characteristic data.

[0089] Here, the combustion heat release data is used to reflect the combustion state of gasoline and lean air-fuel mixture in the cylinder of the engine; in this disclosure, the combustion heat release data includes, but is not limited to, the amount of combustion heat release, the heat release rate curve, the cylinder pressure curve, the engine work quantity, etc., obtained based on the amount of combustion heat release.

[0090] In step 103, the combustion heat release data is analyzed, calculated, and processed to obtain analytical results characterizing the combustion state inside the cylinder.

[0091] In this embodiment of the disclosure, when the combustion heat release data includes combustion heat release, the combustion heat release corresponding to each crankshaft rotation angle can be sorted to obtain the analysis result, which includes the average value of the combustion heat release; when the combustion heat release data includes cylinder pressure curve, the cylinder pressure curve is differentiated to obtain the analysis result, which includes the cylinder pressure rise rate; when the combustion heat release data includes engine work output, the work output is analyzed based on the cylinder volume to obtain the analysis result, which includes the mean effective pressure; here, the mean effective pressure refers to the effective work output per unit cylinder working volume.

[0092] In step 104, when the analysis result exceeds the compression ignition threshold, it can be determined that a compression ignition event has occurred in the cylinder.

[0093] Here, the compression ignition event in the cylinder of the spark-compression ignition gasoline engine disclosed herein is manifested as follows: through the ignition process of the spark plug and the compression ignition process of the piston moving up and down, the gasoline and lean mixture in the cylinder are burned, presenting a spark-compression ignition combustion state.

[0094] Based on the analysis results shown in the above embodiments of this 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, a compression ignition event is determined to have occurred in the cylinder; when the average value of combustion heat release does not exceed the heat threshold, a compression ignition event is determined not to have occurred in the cylinder. When the analysis results include 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, a compression ignition event is determined to have occurred in the cylinder; when the maximum value of the cylinder pressure rise rate does not exceed the cylinder pressure curve threshold, a compression ignition event is determined not to have occurred in the cylinder. When the analysis results include mean effective pressure, the compression ignition threshold includes an effective pressure threshold. When the mean effective pressure exceeds the effective pressure threshold, a compression ignition event is determined to have occurred in the cylinder; when the mean effective pressure does not exceed the effective pressure threshold, a compression ignition event is determined not to have occurred in the cylinder.

[0095] It should be noted that the analysis results in this embodiment 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.

[0096] In some embodiments, the compression ignition event determination method proposed in this disclosure further includes:

[0097] During the 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.

[0098] When the compression ignition event does not occur in the cylinder, a second signal is generated, which indicates that the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event in the next working cycle.

[0099] 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 to indicate that a compression ignition event has occurred in the cylinder, and the current ignition angle corresponding to the cylinder can be used to control the occurrence of the compression ignition event in subsequent working cycles; the second signal is output as a low-level digital signal to indicate that no compression ignition event has occurred in the cylinder, and the ignition angle needs to be adjusted in subsequent working cycles to control the occurrence of the compression ignition event in the cylinder.

[0100] For example, the first signal is transmitted as signal 1 (true), and the second signal is transmitted as signal 0 (false).

[0101] In this embodiment of the present disclosure, after acquiring the first signal generated by the cylinder, the preset ignition angle and preset combustion state parameters corresponding to the cylinder are acquired 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).

[0102] Here, the preset ignition angle is the current ignition angle of the cylinder; the preset combustion state parameters include the crankshaft angle corresponding to a combustion heat release rate of 50%, and the engine cylinder is controlled by MAP1 and MAP2 to perform ignition compression combustion in subsequent working cycles.

[0103] For example, the cylinder is ignited using the preset ignition angle output by MAP1, and the ignition angle is corrected based on the preset combustion state parameters output by MAP2.

[0104] In this embodiment of the present disclosure, the determination result of the compression ignition event is output through digital signals using the first signal and the second signal, so that the engine can effectively identify the determination result, so as to accurately control the engine combustion state in the future.

[0105] The compression ignition event determination method proposed in this disclosure analyzes the combustion heat release data determined by the crankshaft angle during engine rotation, and determines the compression ignition event in the engine cylinder based on the relationship between the analysis results and the compression ignition threshold. Thus, the determination method proposed in this disclosure is simple, can quickly, accurately, and reasonably determine the compression ignition event in the cylinder, and accurately locate the location of the compression ignition event and the crankshaft angle. This helps to effectively control the engine cylinder to achieve compression ignition combustion, and further improves the engine combustion efficiency compared to blindly controlling ignition without knowing the engine combustion state.

[0106] In some examples, the combustion heat release data presented in this disclosure may include a combustion heat release rate curve.

[0107] In some embodiments, step 102, determining the combustion heat release data of the engine cylinders based on a plurality of crankshaft angles, includes:

[0108] Determine the cylinder pressure data and cylinder volume corresponding to each of the multiple crankshaft rotation angles;

[0109] Based on the cylinder pressure data and cylinder volume corresponding to each crankshaft rotation angle, the combustion heat release rate curve of the engine cylinder is determined.

[0110] Here, the combustion heat release rate curve is formed based on the combustion heat release rate of the cylinder at multiple crankshaft angles. Specifically, the combustion heat release rate is determined by the cylinder characteristic data (including cylinder pressure data and cylinder volume) corresponding to each crankshaft angle θ, and then the combustion heat release rate curve is obtained based on the combustion heat release rates of multiple crankshaft angles θ. Here, the combustion heat release rate (dQ / dθ) is used to characterize the change of the instantaneous heat release energy Q of the cylinder at each crankshaft angle θ based on the crankshaft angle θ.

[0111] The embodiments of this disclosure determine the curve change value of combustion heat release rate by using the cylinder pressure data corresponding to the crankshaft rotation angle and the cylinder internal volume. This can concretely characterize the combustion heat release data in the cylinder, and effectively determine the occurrence of compression ignition events in the cylinder through the data analysis results of the curve change value.

[0112] In some embodiments, the method proposed in the above embodiments of this disclosure for determining the combustion heat release rate curve of the engine cylinder based on the cylinder pressure data and cylinder volume corresponding to each crankshaft rotation angle includes:

[0113] Determine the i-th degree crankshaft angle from among the plurality of crankshaft angles, where i is an integer;

[0114] Determine the cylinder pressure difference between the cylinder pressure data corresponding to the (i+1)th degree crankshaft angle and the cylinder pressure data corresponding to the (i-1)th degree crankshaft angle;

[0115] Determine the volume difference between the cylinder internal volume corresponding to the (i+1)th degree crankshaft rotation angle and the cylinder internal volume corresponding to the (i-1)th degree crankshaft rotation angle;

[0116] The 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 degree crankshaft angle, and the product of the cylinder pressure difference and the cylinder internal volume corresponding to the i-th degree crankshaft angle.

[0117] Here, firstly, the calibrated crankshaft angle (the crankshaft angle corresponding to the piston of the cylinder reaching the top dead center of the compression) is defined as 0 degrees. During the rotation of the crankshaft angle, the i-th degree crankshaft angle corresponding to each preset angle increment of the cylinder is determined. It should be noted that the preset angle increment proposed in this disclosure is an integer, and the angle interval between i and i-1, and between i and i+1 is the same as the preset angle increment. Here, the preset angle increment is 1 degree.

[0118] In this disclosure, the cylinder pressure data (Pi) corresponding to the i-th crankshaft angle can be obtained from the cylinder pressure signal output by the cylinder pressure sensor; the cylinder internal volume (Vi) corresponding to the i-th crankshaft angle can be obtained from the following formulas (1) and (2):

[0119]

[0120]

[0121] Here, Vc is the volume of the combustion chamber on the piston top surface inside 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 i∈[-180, 180].

[0122] In this embodiment of the disclosure, 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, the combustion heat release rate (dQ / di, i.e., Qi) can be obtained by formula (3):

[0123]

[0124] Here, Pi is the cylinder pressure data corresponding to the i-th crankshaft angle, and Vi is the cylinder internal 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 internal 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 internal volume corresponding to the (i+1)-th crankshaft angle; k is the thermodynamic polyvariance coefficient, which is a preset parameter. In this embodiment of the present disclosure, k for the spark-compression ignition gasoline engine can be set to 1.35, where i∈[-180, 180].

[0125] This embodiment of the present disclosure effectively determines the change in combustion heat release when the crankshaft angle changes by using the cylinder pressure data and cylinder volume corresponding to the i-th degree crankshaft angle, the (i-1)-th degree crankshaft angle, and the (i+1)-th degree crankshaft angle, respectively, thus obtaining the combustion heat release rate and a combustion heat release rate curve. The combustion heat release rate curve is used to concretely characterize the combustion heat release data in the cylinder.

[0126] See Figure 2 , Figure 2 This is a flowchart illustrating a compression ignition event determination method according to an exemplary embodiment. Figure 2 In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis results include curve variation values; combined with Figure 2 As shown, the data analysis of the combustion heat release data in step 103 to obtain the analysis results can be implemented through the following steps:

[0127] Step 1031: Determine the preset crankshaft angle range corresponding to the cylinder;

[0128] Step 1032: Based on the preset crankshaft angle range, 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 range.

[0129] Here, the analysis results include curve change values, and step 104 can be implemented through step 1041:

[0130] Step 1041: When the curve change value exceeds the compression ignition threshold, it is determined that a compression ignition event has occurred in the cylinder.

[0131] In step 1031, the preset angle range can be pre-set or dynamically adjusted. In this disclosure, the preset crankshaft angle range can be the angle range corresponding to the crankshaft rotation when the piston moves from the top dead center of the compression stroke to the bottom dead center of the compression stroke; the preset crankshaft angle range can also be the angle range between the crankshaft angle (i.e., the ignition angle) corresponding to the piston's movement from the spark plug ignition position to the corresponding crankshaft angle when the piston moves to the top dead center of the compression stroke and then to a specified position.

[0132] It should be noted that in this disclosure, the engine cylinder fully combusts and releases heat and performs work within a preset crankshaft rotation angle range.

[0133] In some embodiments, the step 1031, determining the preset crankshaft angle range corresponding to the cylinder, can be implemented in the following ways:

[0134] Determine the 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 top dead center position of the compression stroke;

[0135] The first angle range is determined based on the calibrated crankshaft angle and the first preset number of crankshaft angles corresponding to the preset angle increment, in turn, subtracted from the calibrated crankshaft angle.

[0136] Based on the calibrated crankshaft angle and the second preset number of crankshaft angles corresponding to the preset angle increment, the second angle range is determined;

[0137] Based on the first angle range and the second angle range, the preset crankshaft angle range is determined.

[0138] In this disclosure, the calibrated crankshaft angle (the crankshaft angle corresponding to the piston of the cylinder reaching the top dead center of the compression) is defined as 0 degrees; the first preset quantity and the second preset quantity can be preset, and the first preset quantity and the second preset quantity can be the same or different.

[0139] For example, determining the first angle range by successively subtracting a first preset number of crankshaft angles corresponding to a preset angle increment from the calibrated crankshaft angle can be implemented as follows: determining the first angle range as (-20, 0] based on the crankshaft angle obtained by successively subtracting 20 1-degrees from 0 degrees; determining the second angle range by successively increasing a second preset number of crankshaft angles corresponding to a preset angle increment from the calibrated crankshaft angle can be implemented as determining the second angle range as [0, 70] based on the crankshaft angle obtained by successively increasing 70 1-degrees from 0 degrees.

[0140] Here, determining the preset crankshaft angle range based on the first angle range and the second angle range includes: taking the set of the first angle range and the second angle range as the preset crankshaft angle range; for example, the preset crankshaft angle range is (-20, 70).

[0141] This embodiment of the present disclosure can locate the area where the engine cylinder is fully combusted by obtaining a preset crankshaft angle range, which further makes the analysis of combustion heat release data more representative and improves the accuracy of determining the occurrence of compression ignition events.

[0142] In step 1032, based on the preset crankshaft angle range, 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 range. This can be implemented by sorting the curve values ​​(i.e., the combustion heat release rates corresponding to all crankshaft angles) of the combustion heat release rate curve within the preset crankshaft angle range and determining the minimum value of the curve value of the combustion heat release rate curve. Correspondingly, in step 1041, when the minimum value of the curve exceeds the compression ignition threshold (e.g., the minimum compression ignition threshold), it is determined that a compression ignition event has occurred in the cylinder.

[0143] By determining the curve change value of the combustion heat release rate, the combustion heat release data in the cylinder can be concretely characterized, and the occurrence of compression ignition events in the cylinder can be determined by analyzing the curve change value.

[0144] In some embodiments, the curve change value includes the maximum value of the combustion heat release rate curve within the 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; the step of performing data analysis on the combustion heat release rate curve of the cylinder based on the preset crankshaft angle range to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle range includes:

[0145] The maximum value of the combustion heat release rate curve within the preset crankshaft angle range is obtained by analyzing and organizing the curve values ​​of the curve.

[0146] And / or,

[0147] The extreme values ​​of the curvature change are obtained by analyzing and calculating the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range.

[0148] In this embodiment of the disclosure, the curve values ​​corresponding to all crankshaft angles within the preset crankshaft angle range, 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 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), and the 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 taken as the curvature change extreme value.

[0149] Here, the curvature change curve formed by the curvature change value can reflect the degree of change in the combustion heat release rate over a preset angle increment. When the degree of change in the combustion heat release rate is close to the degree of change in the compression ignition combustion heat release rate, the effective occurrence of the in-cylinder compression ignition event can be determined. Here, in this disclosure, the degree of change in the compression ignition combustion heat release rate can be characterized by the compression ignition threshold.

[0150] In some embodiments, the step of analyzing and calculating the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the extreme values ​​of the curvature change includes:

[0151] Determine the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft angles within the preset crankshaft angle range;

[0152] Determine the smallest ratio among a plurality of ratios between the plurality of differences and the preset angle increment;

[0153] The absolute value of multiple minimum ratios is taken as the extreme value of the curvature change.

[0154] For example, in conjunction with the above disclosure, the curvature change value (2dQ / di) corresponding to the i-th degree crankshaft angle within the preset crankshaft angle range is obtained by the following formula (4).

[0155]

[0156] It should be noted that Q i -Q i-1It is expressed as the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft rotation angles; the curve values ​​of the combustion heat release rate curves, 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, and at this time, i is an integer, i is located within the preset crankshaft rotation angle range.

[0157] The smallest ratio among all ratios obtained according to formula (4) in this disclosure. Then, calculate the absolute value of the minimum ratio. And this absolute value is taken as the extreme value of the curvature change (that is, the minimum value of the curvature change).

[0158] This embodiment of the present disclosure obtains the maximum 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. This can concretely characterize the combustion heat release state in the cylinder, so as to effectively determine the occurrence of compression ignition events by the maximum value of the curve and / or the extreme value of the curvature change.

[0159] In some embodiments, the compression ignition threshold includes a first compression ignition threshold and a second compression ignition threshold; determining that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold includes:

[0160] When the maximum value of the curve exceeds the first compression ignition threshold, and / or the extreme value of the curvature change exceeds the second compression ignition threshold, a compression ignition event is determined to have occurred in the cylinder.

[0161] Here, the first compression ignition threshold includes the maximum value of the compression ignition combustion heat release rate curve when the cylinder is in compression ignition condition, which is used to characterize that efficient compression ignition combustion has occurred in the cylinder. Here, the first compression ignition threshold can be the maximum value of the combustion heat release rate curve in a working cycle in which a compression ignition event occurs in the cylinder, or it can be the average of the maximum values ​​of the combustion heat release rate curves in multiple working cycles in which compression ignition events occur.

[0162] The second compression ignition threshold is represented by the extreme value of the curvature change of the compression ignition combustion heat release rate curve when the cylinder is in compression ignition condition. Here, the extreme value of the curvature change is the minimum value of the curvature change, used to characterize the position corresponding to the maximum degree of change in the compression ignition combustion heat release rate. The second compression ignition threshold can be the minimum value of the curvature change of the compression ignition combustion heat release rate curve within a working cycle in which a compression ignition event occurs, or it can be the average of the minimum values ​​of the curvature change of the combustion heat release rate curves within multiple working cycles in which compression ignition events occur.

[0163] In this 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 limit can be set between 3 and 5.

[0164] In practical implementation, in some examples, when the maximum value of the curve value is... When the first compression ignition threshold limit1 is exceeded, a compression ignition event can be determined to have occurred in the cylinder; in other examples, when the curvature change reaches an extreme value... When the second compression ignition threshold limit2 is exceeded, a compression ignition event can be determined to have occurred in the cylinder; in some other examples, when the maximum value of the curve value is reached... Exceeding the first compression ignition threshold limit1, and the curvature change extreme value When the second compression ignition threshold limit2 is exceeded, it can be determined that a compression ignition event has occurred in the cylinder.

[0165] Here, the relationship between the maximum value of the curve and the first compression ignition threshold can quickly determine the occurrence of a compression ignition event, which helps to speed up the subsequent engine ignition control process; the relationship between the extreme value of the curvature change and the second compression ignition threshold can more accurately determine the occurrence of a compression ignition event, which helps to improve the accuracy of subsequent engine ignition control; and by combining the relationship between the maximum value of the curve and the first compression ignition threshold and the relationship between the extreme value of the curvature change and the second compression ignition threshold, it is possible to determine whether a compression ignition event has occurred in the cylinder more efficiently and accurately, thereby improving the diversity and reliability of determining the occurrence of compression ignition events in the cylinder.

[0166] In some embodiments, the cylinder includes multiple cylinders; determining that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold includes:

[0167] When the analysis result determined by independently analyzing the combustion heat release data corresponding to each of the multiple cylinders exceeds the compression ignition threshold, a compression ignition event is determined to have occurred in the cylinder.

[0168] Here, the spark-compression ignition gasoline engine proposed in this disclosure may have multiple cylinders, which may be three, four or five, etc., and this disclosure does not limit this.

[0169] It should be noted that combustion within each cylinder is independent; therefore, acquiring combustion heat release data within the cylinder, obtaining analysis results, and determining the occurrence of a compression ignition event are all handled independently by the engine's control module for each cylinder. Here, the compression ignition threshold for each cylinder is also determined based on the combustion heat release data of that cylinder during its historical operating cycles in which a compression ignition event occurred.

[0170] This embodiment of the invention analyzes and judges multiple cylinders of the engine independently, which facilitates the subsequent individual ignition control of each cylinder. Compared with unified ignition control, it takes into account the differences between cylinders and further improves the combustion efficiency of the engine.

[0171] The following describes a specific application embodiment of the compression ignition event determination method proposed in this disclosure, in conjunction with the above-described embodiments.

[0172] Here, the method for determining compression ignition events can be implemented in spark-compression ignition gasoline engines. By installing pressure sensors in each cylinder of the spark-compression ignition gasoline engine, and through experimental method design and processing of cylinder pressure data, it can be determined whether a compression ignition event has occurred. See also... Figure 3 ; Figure 3 This is a flowchart illustrating a compression ignition event determination method according to an exemplary embodiment. Figure 3 ;like Figure 3 As shown, the method for determining compression ignition events proposed in this disclosure can be implemented through the following steps:

[0173] Step 301: Measure the combustion heat release rate of the cylinder based on the crankshaft angle;

[0174] Using the crankshaft angle as a reference axis, the cylinder pressure, current crankshaft angle, and cylinder volume of each cylinder are monitored at each crankshaft angle obtained when the engine rotates by 1 degree. The combustion heat release rate (dQ / dθ) of each cylinder is obtained by processing the above data. Here, the combustion heat release rate (dQ / dθ) is used to characterize the change of instantaneous heat release energy Q of the cylinder at each crankshaft angle θ based on the crankshaft angle θ.

[0175] Here, the combustion heat release rate (dQ / dθ) at the crankshaft rotation angle, i.e., Qi, can be obtained by formula (3):

[0176]

[0177] It should be noted that Pi is the cylinder pressure data corresponding to the i-th crankshaft angle; Vi is the cylinder internal 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 internal 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 internal volume corresponding to the (i+1)-th crankshaft angle; k is the thermodynamic polyvariance coefficient, which is a preset parameter. In this embodiment of the present disclosure, k of the spark-compression ignition gasoline engine can be set to 1.35, where i∈[-180, 180].

[0178] Step 302: Obtain the combustion heat release rate curve corresponding to the combustion heat release rate;

[0179] See Figure 4 , Figure 4This is a test analysis diagram of in-cylinder combustion data according to an exemplary embodiment; such as Figure 4 As shown, the horizontal axis of this coordinate system represents the crankshaft angle, and the vertical axis represents the crankshaft angle CA corresponding to the combustion heat release rate. Figure 4 The solid line in the figure represents the combustion heat release rate curve corresponding to the combustion heat release rate.

[0180] Step 303: Differentiate the combustion heat release rate curve based on the crankshaft angle, and determine the extreme value of the curvature change of the combustion heat release rate curve within the preset crankshaft angle range.

[0181] 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., an interval of a preset angle increment). The minimum value among multiple curvature change values ​​(2dQ / dθ) within the preset crankshaft angle interval is determined, and the absolute value of the minimum value is taken as the curvature change extreme value.

[0182] Based on the above disclosure, the curvature change value (2dQ / di) corresponding to the i-th degree crankshaft rotation angle within the preset crankshaft rotation angle range is obtained by the following formula (4).

[0183]

[0184] Here, i is an integer, and i is located within the preset crankshaft angle range.

[0185] The minimum ratio among all ratios obtained according to formula (4) in this disclosure. Then, calculate the absolute value of the minimum ratio. And this absolute value is taken as the extreme value of the curvature change.

[0186] Combination Figure 4 , Figure 4 The dashed line in the figure represents the curvature change curve formed by the curvature change value of the combustion heat release rate curve. Here, 0 degrees in the horizontal axis represents the crankshaft angle corresponding to the piston reaching the top dead center position of the cylinder compression. 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).

[0187] Combination Figure 4 It can be seen that when the curvature of the combustion heat release rate curve changes to its maximum, the corresponding curvature change curve has an extreme value of curvature change. By comparing the extreme value of curvature change and the second compression ignition threshold, we can determine the similarity between the position of the maximum curvature change of the combustion heat release rate curve and the position of the maximum change of the compression ignition combustion heat release rate, and thus determine whether a compression ignition event has occurred in the cylinder in the current cycle.

[0188] Step 304: Obtain the second compression ignition threshold;

[0189] Here, the second compression ignition threshold limit2 is obtained, which can be set between 3 and 5.

[0190] Step 305: Determine whether the extreme value of curvature change is greater than the second compression ignition threshold; if yes, proceed to step 306; otherwise, proceed to step 307.

[0191] Step 306: Determine that a compression ignition event has occurred in the cylinder and generate a first signal;

[0192] Here, the first signal is transmitted in the form of digital signal 1 (true).

[0193] Step 307: Determine that no compression ignition event has occurred in the cylinder, and generate a second signal.

[0194] Here, the second signal is transmitted in the form of a digital signal 0 (false).

[0195] Steps 306 and 307 can be implemented in the following ways:

[0196] Here, when When, the judgment result is transmitted as signal 1 (true), when When the result is false, the decision is transmitted using signal 0.

[0197] In this disclosure, the spark-ignition compression-ignition gasoline engine includes multiple cylinders. Each cylinder is independently subjected to data acquisition, signal processing, and compression ignition event determination. 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 to promote compression ignition in the cylinder in subsequent working cycles.

[0198] The compression ignition event determination method proposed in this disclosure can accurately and reasonably determine the compression ignition event in the engine cylinder, which helps to effectively control the ignition and compression ignition combustion in the engine cylinder.

[0199] The following describes the engine equipment provided in this disclosure for implementing the compression ignition event determination method described above. See also: Figure 5 , Figure 5 This is a schematic block diagram of the engine structure according to an exemplary embodiment, such as... Figure 5As shown, engine 500 includes at least one processor 501 and a memory 502. Various components in engine 500 are coupled together via a bus system 503. It is understood that the bus system 503 is used to implement communication between these components. In addition to a data bus, bus system 503 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 5 The general designated all buses as Bus System 503.

[0200] 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. Among them, the general-purpose processor can be a microprocessor or any conventional processor.

[0201] Memory 502 may be removable, non-removable, or a combination thereof. An exemplary hardware device may be solid-state memory. Memory 502 may optionally include one or more storage devices physically located remote from processor 501.

[0202] Memory 502 may include volatile memory or non-volatile memory, or both. Non-volatile memory may be read-only memory (ROM), and volatile memory may be random access memory (RAM). The memory 502 described in this disclosure is intended to include any suitable type of memory.

[0203] In some embodiments, the memory 502 is capable of storing data to support various operations. Examples of such data include programs, modules, and data structures, or subsets or supersets thereof. In this embodiment of the disclosure, the memory 502 stores an operating system 5021 and a compression ignition event determination device 5022; specifically:

[0204] Operating system 5021 includes system programs for handling various basic system services and performing hardware-related tasks, such as the framework layer, core library layer, and driver layer, which are used to implement various basic business functions and handle hardware-based tasks.

[0205] In some embodiments, the compression ignition event determination device provided in this disclosure can be implemented in software. Figure 5A compression ignition event determination device 5022 stored in memory 502 is shown. This device can be software in the form of programs or plug-ins, 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 therefore be arbitrarily combined or further separated according to their implemented functions. The functions of each module will be described below.

[0206] In other embodiments, the compression ignition event determination device provided in this disclosure can be implemented in hardware. As an example, the compression ignition event determination device provided in this disclosure can be a processor in the form of a hardware decoding processor, which is programmed to execute the compression ignition event determination method provided in this disclosure. For example, the processor in the form of a hardware decoding processor can 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.

[0207] The following description continues to illustrate the exemplary structure of the compression ignition event determination device 5022 provided in the embodiments of this disclosure as a software module. In some embodiments, such as... Figure 5 As shown, the software module stored in the compression ignition event determination device 5022 in the memory 502 may include:

[0208] The acquisition module 50221 is configured to acquire multiple crankshaft rotation angles obtained by sequentially rotating the crankshaft of the engine by a preset angle increment;

[0209] The determination module 50222 is configured to determine the combustion heat release data of the engine cylinders based on multiple crankshaft angles;

[0210] Analysis module 50223 is configured to perform data analysis on the combustion heat release data and obtain analysis results;

[0211] The determination module 50224 is configured to determine that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold.

[0212] In some embodiments, the combustion heat release data includes a combustion heat release rate curve, and the analysis results include curve change values;

[0213] The analysis module 50223 is further configured to determine a preset crankshaft angle range corresponding to the cylinder; and based on the preset crankshaft angle range, to 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 range.

[0214] In some embodiments, the curve change value includes the maximum value of the curve value of the combustion heat release rate curve within the 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;

[0215] The analysis module 50223 is further configured to analyze and organize 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.

[0216] In some embodiments, the analysis module 50223 is further configured to: determine the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft angles in a plurality of crankshaft angles within the preset crankshaft angle range; determine the minimum ratio among a plurality of ratios between the plurality of differences and the preset angle increment; and take the absolute value of the minimum ratio as the curvature change extreme value.

[0217] 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 has occurred 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.

[0218] In some embodiments, the analysis module 50223 is further configured to determine the 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 top dead center of compression; based on the calibrated crankshaft angle and the calibrated crankshaft angle, a first angle interval is determined by successively subtracting a first preset number of crankshaft angles corresponding to the preset angle increment; based on the calibrated crankshaft angle and the calibrated crankshaft angle, a second angle interval is determined by successively increasing a second preset number of crankshaft angles corresponding to the preset angle increment; based on the first angle interval and the second angle interval, a preset crankshaft angle interval is determined.

[0219] In some embodiments, the determining module 50222 is further configured to determine the cylinder pressure data and cylinder volume corresponding to each of the plurality of crankshaft angles; and to determine the combustion heat release rate curve of the engine cylinder based on the cylinder pressure data and cylinder volume corresponding to each crankshaft angle.

[0220] In some embodiments, the determining module 50222 is further configured to: determine the i-th crankshaft angle among a plurality of 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 internal volume corresponding to the (i+1)-th crankshaft angle and the cylinder internal 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 internal volume corresponding to the i-th crankshaft angle.

[0221] In some embodiments, the cylinders include a plurality of cylinders; the determination module 50224 is further configured to determine that a compression ignition event has occurred 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.

[0222] In some embodiments, the apparatus further includes: a signal generation module 50225 configured to generate a first signal when the compression ignition event occurs in the cylinder during 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; and to generate a second signal when the compression ignition event does not occur in the cylinder, the second signal being used to indicate that the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event during the next working cycle.

[0223] It should be noted that the description of the apparatus in this embodiment is similar to the description of the method embodiment described above, and has similar beneficial effects as the method embodiment, so it will not be repeated.

[0224] This disclosure provides a computer program product or computer program that 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 this disclosure.

[0225] This disclosure provides a computer-readable storage medium storing executable instructions, wherein the executable instructions, when executed by a processor, will cause the processor to execute the compression ignition event determination method provided in this disclosure.

[0226] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a variety of devices including one or any combination of the above-mentioned memories.

[0227] In some embodiments, executable instructions may take 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 standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0228] As an example, executable instructions may, but do not necessarily, correspond to files in a file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple collaborating files (e.g., a file that stores one or more modules, subroutines, or code sections).

[0229] As an example, executable instructions can be deployed to execute on a single computing device, or on multiple computing devices located in one location, or on multiple computing devices distributed across multiple locations and interconnected via a communication network.

[0230] In summary, the embodiments disclosed herein can accurately and reasonably determine the compression ignition event in the engine cylinder, which helps to effectively control the combustion of gasoline engines by ignition compression ignition in the cylinder.

[0231] The above description is merely an embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this disclosure are included within the scope of protection of this disclosure.

Claims

1. A method for determining compression ignition events, characterized in that, When applied to an engine, the method includes: The crankshaft rotation angles of the engine are obtained by sequentially rotating the crankshaft by a preset angle increment; The combustion heat release data of the engine cylinders are determined based on multiple crankshaft rotation angles; The combustion heat release data were analyzed to obtain the analysis results; When the analysis result exceeds the compression ignition threshold, it is determined that a compression ignition event has occurred in the cylinder; During the 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, which indicates that the cylinder needs to adjust the ignition angle to control the occurrence of the compression ignition event in the next working cycle. After acquiring the first signal generated by the cylinder, the preset ignition angle and preset combustion state parameters corresponding to the cylinder are acquired 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). Wherein, the preset ignition angle is the current ignition angle of the cylinder; the preset combustion state parameters include the crankshaft angle corresponding to a combustion heat release rate of 50%; The cylinder is ignited using the preset ignition angle output from the ignition angle three-dimensional table (MAP1), and the ignition angle is corrected based on the preset combustion state parameters output from the combustion heat release control three-dimensional table (MAP2).

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 results include curve variation values; the data analysis of the combustion heat release data to obtain analysis results includes: Determine the preset crankshaft angle range corresponding to the cylinder; Based on the preset crankshaft angle range, 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 range.

3. The method according to claim 2, characterized in that, The curve change value includes the maximum value of the combustion heat release rate curve within the 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; the step of performing data analysis on the combustion heat release rate curve of the cylinder based on the preset crankshaft angle range to obtain the curve change value of the combustion heat release rate curve within the preset crankshaft angle range includes: The maximum value of the combustion heat release rate curve within the preset crankshaft angle range is obtained by analyzing and organizing the curve values ​​of the curve. And / or, The extreme values ​​of the curvature change are obtained by analyzing and calculating the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range.

4. The method according to claim 3, characterized in that, The step of analyzing and calculating the curve values ​​of the combustion heat release rate curve within the preset crankshaft angle range to obtain the extreme values ​​of the curvature change includes: Determine the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft angles within the preset crankshaft angle range; Determine the smallest ratio among a plurality of ratios between the plurality of differences 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; determining that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold includes: When the maximum value of the curve exceeds the first compression ignition threshold, and / or the extreme value of the curvature change exceeds the second compression ignition threshold, the compression ignition event is determined to have occurred in the cylinder.

6. The method according to claim 2, characterized in that, Determining the preset crankshaft angle range corresponding to the cylinder includes: Determine the 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 top dead center position of the compression stroke; The first angle range is determined based on the calibrated crankshaft angle and the first preset number of crankshaft angles corresponding to the preset angle increment, in turn, subtracted from the calibrated crankshaft angle. Based on the calibrated crankshaft angle and the second preset number of crankshaft angles corresponding to the preset angle increment, the second angle range is determined; Based on the first angle range and the second angle range, the preset crankshaft angle range is determined.

7. The method according to any one of claims 2 to 6, characterized in that, The determination of the combustion heat release data of the engine cylinders based on multiple crankshaft rotation angles includes: Determine the cylinder pressure data and cylinder volume corresponding to each of the multiple crankshaft rotation angles; Based on the cylinder pressure data and cylinder volume corresponding to each crankshaft rotation angle, the combustion heat release rate curve of the engine cylinder is determined.

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

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

10. A device for determining a compression ignition event, characterized in that, The device includes: The acquisition module is configured to acquire multiple crankshaft angles obtained by sequentially rotating the engine's crankshaft by a preset angle increment; The determination module is configured to determine the combustion heat release data of the engine cylinders based on multiple crankshaft angles; The analysis module is configured to perform data analysis on the combustion heat release data and obtain analysis results; The determination module is configured to determine that a compression ignition event has occurred in the cylinder when the analysis result exceeds the compression ignition threshold. The signal generation module is configured to generate a first signal when a compression ignition event occurs in the cylinder during the current working cycle; the first signal indicates that the current ignition angle corresponding to the cylinder is sufficient to control the compression ignition event; and generate a second signal when no compression ignition event occurs in the cylinder, the second signal indicating that the cylinder needs to adjust its ignition angle to control the compression ignition event in the next working cycle. After acquiring the first signal generated by the cylinder, a preset ignition angle and a preset combustion state corresponding to the cylinder are acquired based on the first signal. The parameters are set, 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); wherein, the preset ignition angle is the current ignition angle of the cylinder; the preset combustion state parameters include the crankshaft angle corresponding to a combustion heat release rate of 50%; the cylinder is ignited using the preset ignition angle output by the ignition angle three-dimensional table (MAP1), and the ignition angle is corrected based on the preset combustion state parameters output by the combustion heat release control three-dimensional table (MAP2).

11. The apparatus according to claim 10, characterized in that, The combustion heat release data includes a combustion heat release rate curve, and the analysis results include curve variation values. The analysis module is further configured to determine a preset crankshaft angle range corresponding to the cylinder; and based on the preset crankshaft angle range, to 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 range.

12. The apparatus according to claim 11, characterized in that, The curve change value includes the maximum value of the combustion heat release rate curve within the 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; The analysis module is further configured to analyze and organize 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.

13. The apparatus according to claim 12, characterized in that, The analysis module is further configured to: determine the difference between the curve values ​​of the combustion heat release rate curves corresponding to two adjacent crankshaft angles within the preset crankshaft angle range; determine the minimum ratio among multiple ratios between the multiple differences and the preset angle increment; and take the absolute value of the minimum ratio as the curvature change extreme value.

14. The apparatus according to claim 12, 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 has occurred 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.

15. The apparatus according to claim 11, characterized in that, The analysis module is further configured to determine the 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 top dead center of compression; based on the calibrated crankshaft angle and the first preset number of crankshaft angles corresponding to the preset angle increment are sequentially subtracted from the calibrated crankshaft angle to determine the first angle interval; based on the calibrated crankshaft angle and the second preset number of crankshaft angles corresponding to the preset angle increment are sequentially added to the calibrated crankshaft angle to determine the second angle interval; based on the first angle interval and the second angle interval, the preset crankshaft angle interval is determined.

16. The apparatus according to any one of claims 10 to 15, characterized in that, The determining module is further configured to determine the cylinder pressure data and cylinder volume corresponding to each of the plurality of crankshaft angles; and to determine the combustion heat release data of the engine cylinder based on the cylinder pressure data and cylinder volume corresponding to each crankshaft angle.

17. The apparatus according to claim 16, characterized in that, The determining module is further configured to: determine the i-th crankshaft angle among a plurality of 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 internal volume corresponding to the (i+1)-th crankshaft angle and the cylinder internal volume corresponding to the (i-1)-th crankshaft angle; and determine the combustion heat release data 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 internal volume corresponding to the i-th crankshaft angle.

18. The apparatus according to any one of claims 10 to 15, characterized in that, The cylinder includes multiple cylinders; The determination module is further configured to determine that a compression ignition event has occurred 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.

19. An engine, characterized in that, include: Memory, used to store executable instructions; The processor, when executing executable instructions stored in the memory, implements the compression ignition event determination method according to any one of claims 1 to 9.

20. A computer-readable storage medium, characterized in that, It stores executable instructions for use by a processor to implement the compression ignition event determination method according to any one of claims 1 to 9.

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