CN116816497A - Method and system for identifying combustion stability of reciprocating internal combustion engine - Google Patents
Method and system for identifying combustion stability of reciprocating internal combustion engine Download PDFInfo
- Publication number
- CN116816497A CN116816497A CN202311106057.5A CN202311106057A CN116816497A CN 116816497 A CN116816497 A CN 116816497A CN 202311106057 A CN202311106057 A CN 202311106057A CN 116816497 A CN116816497 A CN 116816497A
- Authority
- CN
- China
- Prior art keywords
- cylinder
- internal combustion
- crankshaft
- reciprocating internal
- engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 178
- 238000000034 method Methods 0.000 title claims abstract description 29
- 230000001133 acceleration Effects 0.000 claims abstract description 86
- 238000005070 sampling Methods 0.000 claims abstract description 8
- 230000001960 triggered effect Effects 0.000 claims description 8
- 238000004458 analytical method Methods 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 238000012360 testing method Methods 0.000 claims description 7
- 238000012545 processing Methods 0.000 claims description 6
- 238000013139 quantization Methods 0.000 claims description 4
- 238000012163 sequencing technique Methods 0.000 claims description 2
- 238000010304 firing Methods 0.000 claims 5
- 238000004364 calculation method Methods 0.000 description 4
- 230000000007 visual effect Effects 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008447 perception Effects 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
The invention provides a method and a system for identifying combustion stability of a reciprocating internal combustion engine, wherein the method comprises the following steps: acquiring data such as crankshaft rotation speed, ignition signals of each cylinder, preset sampling frequency and the like of the reciprocating internal combustion engine under a target working condition through a rotation speed sensor; converting the crankshaft rotational speed into crankshaft angular acceleration; according to the working sequence of the cylinders, the angular acceleration of the crankshaft is corresponding to each cylinder of the internal combustion engine; calculating angular acceleration covariance of each cylinder at the working time; the stability of combustion of the reciprocating internal combustion engine is judged by covariance. The method for identifying the combustion stability of the reciprocating internal combustion engine provided by the invention realizes accurate acquisition of the rotating speed by using the rotating speed sensor of the reciprocating internal combustion engine, converts the rotating speed of the crankshaft into the angular acceleration of the crankshaft and classifies the angular acceleration data, and then realizes simple identification of the combustion stability of the reciprocating internal combustion engine by introducing parameters representing the data stability.
Description
Technical Field
The invention belongs to the technical field of reciprocating internal combustion engines, and particularly relates to a method for identifying combustion stability of a reciprocating internal combustion engine.
Background
In automobile development, abnormal vibration in running of a vehicle, which causes discomfort to a driver, is a frequently encountered trouble problem, and whether combustion of an engine is stable or not is one of the causes of numerous abnormal vibration. However, the combustion stable state of the engine cannot be directly displayed by a sensor or an electric signal of the automobile, and is mostly judged by subjective perception of engine shake. The subjective judgment is difficult to quantitatively determine the problem, and the problem misjudgment is easy to be caused.
In the prior art, combustion analyzers are generally used to test cylinder pressures to calculate a manner of identifying combustion stability of an internal combustion engine. For example, a publication of chinese patent publication No. CN115186501a, entitled "a method for evaluating combustion process stability of an internal combustion engine", discloses calculation and analysis of combustion stability by testing gas pressure in a cylinder.
However, when the combustion stability is tested by using the combustion analyzer, a special cylinder pressure sensor matched with the engine model is required, and meanwhile, the special cylinder pressure sensor is required to be installed, but in the actual testing process, the engine model to be tested is various, so that the special cylinder pressure sensor is required to be manufactured again due to limited use occasions, and then the special cylinder pressure sensor is installed again, and the problems of time and labor waste and high testing cost are caused.
Disclosure of Invention
Based on the above, the invention aims to provide a method and a system for identifying the combustion stability of a reciprocating internal combustion engine, which aim to solve the problems of time and labor waste and higher testing cost of a special cylinder pressure sensor because of limited use occasions and re-manufacturing and then re-installing.
According to the method and the system for identifying the combustion stability of the internal combustion engine, the method comprises the following steps:
acquiring engine crankshaft speed and cylinder ignition signals of the reciprocating internal combustion engine under a target working condition at intervals of a first preset time, wherein the cylinder ignition signals are triggered by a single cylinder in the engine in a power stroke;
traversing the engine crankshaft rotating speeds at all times, and acquiring the crankshaft angular acceleration at the current time according to the engine crankshaft rotating speeds at the previous time and the next time, wherein the crankshaft angular acceleration at any time corresponds to a cylinder of a power stroke at the moment;
classifying and marking the crank angular acceleration at all moments according to the cylinder ignition signals, wherein the marking result is a cylinder number;
and respectively calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number according to a plurality of crank angular acceleration under the same cylinder number, and judging combustion stability of the reciprocating internal combustion engine according to the covariance corresponding to each cylinder.
Compared with the prior art, the method has the advantages that the self-contained rotating speed sensor of the reciprocating internal combustion engine is used, the problem that the combustion stability is judged in a mode that a special cylinder pressure sensor is required to be installed to calculate the cylinder pressure is avoided, the crankshaft rotating speed data of the engine is more accurate in a direct acquisition mode, the crankshaft rotating speed is converted into the crankshaft angular acceleration data, the stability judgment of the crankshaft rotating change in the reciprocating internal combustion engine is more accurate and visual, the crankshaft angular acceleration data are numbered and classified according to the working sequence of the cylinders, the working condition of each cylinder is easier to locate and check, and the combustion stability and the combustion consistency of each cylinder are judged according to the stability parameters by introducing covariance representing the data, so that the simple identification of the combustion stability of the reciprocating internal combustion engine is realized.
Further, the step of acquiring the engine crankshaft speed and the cylinder ignition signal of the reciprocating internal combustion engine under the target working condition at intervals of a first preset time, wherein the cylinder ignition signal is triggered by a single cylinder in the engine in a power stroke, and the step of further comprises the following steps:
the vehicle body electronic stability system ESP reduces the output torque of the engine and adjusts the braking pressure of wheels to control the posture of the vehicle body, and the slip rate and the driving slip rate of the wheels are controlled within the range of a specified stability area so as to enable the vehicle to be in a stable target working condition.
Further, the step of acquiring the engine crankshaft speed and the cylinder ignition signal of the reciprocating internal combustion engine under the target working condition at intervals of a first preset time, wherein the cylinder ignition signal is triggered by a single cylinder in the engine in a power stroke, and the step of further comprises the following steps:
and at least acquiring a certain number of circulating working samples through a rotating speed sensor in the combustion process of the cylinder, wherein the recorded data in the circulating working samples comprise the rotating speed of an engine crankshaft, ignition signals of each cylinder and the duration of recorded data, determining that the first preset time is not lower than a preset sampling frequency threshold value, and the duration of the recorded data is not less than a preset recording duration threshold value.
Further, the step of traversing the engine crankshaft speeds at all times and obtaining the crank angular acceleration at the current time according to the engine crankshaft speeds at the previous time and the next time, wherein the crank angular acceleration at any time corresponds to the cylinder of the power stroke at the time comprises the following steps:
the conversion formula of the step of obtaining the crank angle acceleration at the current moment according to the engine crank rotation speed at the previous moment and the next moment is as follows:
wherein: t represents the first preset time period,represents the angular acceleration of the cylinder at the current t moment,/>Representing the engine crankshaft speed at time t+1, < >>Representing the engine crankshaft speed at time t-1.
Further, the step of classifying and marking the crank angular acceleration at all times according to the cylinder ignition signal, wherein the marking result is a cylinder number comprises the following steps:
and sequencing the numbers of the cylinders according to the working sequence of each cylinder, and programming all crank angle acceleration data recorded from the starting work of ignition of one cylinder to the starting work of ignition of the next cylinder into the same number of the current working cylinder to form a crank angle acceleration data set of each cylinder.
Further, the step of calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number from the plurality of crank angular acceleration under the same cylinder number, respectively, and judging combustion stability of the reciprocating internal combustion engine from the covariance corresponding to each cylinder, respectively, includes:
a covariance COV representing the steady state of the data was introduced to characterize the combustion stability of the engine, which was calculated as follows:
average value->。
Further, the step of calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number from the plurality of crank angular acceleration under the same cylinder number, respectively, and judging combustion stability of the reciprocating internal combustion engine from the covariance corresponding to each cylinder, respectively, includes:
judging whether the covariance corresponding to each cylinder is not more than a preset covariance threshold; if the covariance corresponding to each cylinder is not greater than the preset covariance threshold, the combustion stability of each cylinder is indicated;
acquiring a difference value of covariance corresponding to any two cylinders, and judging whether the difference value is smaller than a preset error threshold value or not; if the difference value of covariance corresponding to any two cylinders is smaller than a preset error threshold value, the combustion of each cylinder is consistent;
when the combustion stability of each cylinder is consistent with the combustion stability of each cylinder, the combustion stability of the reciprocating internal combustion engine is judged.
A system for identifying combustion stability of a reciprocating internal combustion engine according to an embodiment of the present invention, the system comprising:
the crankshaft signal acquisition module is used for acquiring engine crankshaft rotation speed and cylinder ignition signals of the reciprocating internal combustion engine under a target working condition through the rotation speed sensor at intervals of a first preset time;
wherein, bent axle signal acquisition module includes:
the rotating speed sensor is used for testing and acquiring the rotating speed of the crankshaft, the preset sampling frequency, the ignition signal of the cylinder and the preset recording duration data when the reciprocating internal combustion engine burns.
The data processing module is used for converting the acquired crankshaft rotation speed data and classifying the converted crankshaft rotation speed data into corresponding cylinder numbers;
wherein, the data processing module includes:
the data conversion unit is used for acquiring the crank angle acceleration at the current moment according to the crank rotation speeds at the previous moment and the next moment;
and the data classification unit is used for classifying and marking the crank angular acceleration at all moments according to the cylinder ignition signals, and the marking result is a cylinder number.
The analysis judging module is used for introducing a calculated parameter representing the stability state to judge the combustion stability of each cylinder and the combustion consistency of each cylinder, and judging the combustion stability of the reciprocating internal combustion engine according to the combustion stability of each cylinder and the combustion consistency of each cylinder;
wherein, the analysis judging module comprises:
a parameter quantization unit for calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number according to a plurality of crank angular acceleration under the same cylinder number;
and the judging and positioning unit is used for judging the combustion stability of the reciprocating internal combustion engine according to the covariance corresponding to each cylinder.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
FIG. 1 is a flow chart of a method of identifying combustion stability of a reciprocating internal combustion engine in accordance with a first embodiment of the present invention;
FIG. 2 is a flow chart of a method of identifying combustion stability of a reciprocating internal combustion engine in accordance with a second embodiment of the present invention;
fig. 3 is a schematic diagram showing a system for recognizing combustion stability of a reciprocating internal combustion engine according to a third embodiment of the present invention.
The invention will be further described in the following detailed description in conjunction with the above-described figures.
Detailed Description
In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. Several embodiments of the invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, 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 invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Referring to fig. 1, a flowchart of a method for identifying combustion stability of a reciprocating internal combustion engine according to a first embodiment of the present invention is shown, the method includes steps S01 to S04, wherein:
step S01: acquiring engine crankshaft speed and cylinder ignition signals of the reciprocating internal combustion engine under a target working condition at intervals of a first preset time, wherein the cylinder ignition signals are triggered by a single cylinder in the engine in a power stroke;
it should be noted that, since the vehicle engine is a multi-cylinder engine, and the multi-cylinder engine is formed by arranging a plurality of identical cylinders on a machine body to share a crankshaft, in order to keep operation balance, the working principles of the cylinders are identical, but ignition of the cylinders is performed independently in sequence, when the engine is triggered to start, a plurality of cycle working samples during crankshaft rotation can be collected through a rotation speed sensor of the engine when the vehicle is kept in stable operation, wherein each cycle working sample comprises crankshaft rotation speed, preset sampling frequency, ignition signals of the cylinders and preset recording duration data.
Step S02: traversing the engine crankshaft rotating speeds at all times, and acquiring the crankshaft angular acceleration at the current time according to the engine crankshaft rotating speeds at the previous time and the next time, wherein the crankshaft angular acceleration at any time corresponds to a cylinder of a power stroke at the moment;
it can be appreciated that, because the crankshaft rotational speed is a direct numerical representation of the crankshaft rotational speed, and the crankshaft angular acceleration can reflect the crankshaft rotational speed variation, and can accurately determine the stability of the crankshaft rotational variation in the reciprocating internal combustion engine, it is necessary to convert the crankshaft rotational speed into the crankshaft angular acceleration;
specifically, if the average speed of two points is obtained first, and then the acceleration is obtained by difference, the result is that the obtained acceleration change rate is relatively gentle in the stage of fast change of the actual acceleration, so that the error between the calculated acceleration and the actual acceleration is relatively large, and the acquired crankshaft rotation speed data is relatively large, so that the acceleration is obtained by directly adopting the difference between the front point and the rear point, namely, the crankshaft angular acceleration at the current moment is obtained according to the crankshaft rotation speed of the engine at the previous moment and the next moment.
Step S03: classifying and marking the crank angular acceleration at all moments according to the cylinder ignition signals, wherein the marking result is a cylinder number;
it can be understood that, because the cylinder ignition signal indicates the moment when each cylinder starts to work, the crank angle acceleration data obtained after conversion can be numbered and classified to the corresponding cylinder according to the working sequence of each cylinder, so that the condition that confusion is easy to occur when the crank angle acceleration data is classified can be greatly reduced.
Step S04: calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number according to a plurality of crank angular acceleration under the same cylinder number, and judging combustion stability of the reciprocating internal combustion engine according to the covariance corresponding to each cylinder;
it will be appreciated that covariance is a form of quantization most commonly used to reflect a set of discrete levels of data and is an important indicator of accuracy, and therefore, covariance COV representing steady state data is introduced to characterize the combustion stability and combustion consistency of each cylinder, and when the absolute value of the covariance COV is greater, the less stable the combustion of that cylinder and the less consistent the combustion of the other cylinders, i.e., the less stable the combustion of a reciprocating internal combustion engine.
In summary, according to the method for identifying combustion stability of a reciprocating internal combustion engine, by using a rotation speed sensor of the reciprocating internal combustion engine, combustion stability is determined by avoiding a mode of calculating cylinder pressure by installing a special cylinder pressure sensor, engine crankshaft rotation speed data is more accurate in a direct acquisition mode, crankshaft rotation change stability determination in the reciprocating internal combustion engine is more accurate and visual by converting crankshaft rotation speed to crankshaft angular acceleration, crankshaft angular acceleration data is numbered and classified according to a working sequence of cylinders, so that each cylinder working condition is easier to locate and view, and combustion stability and combustion consistency of each cylinder are determined according to stability parameters by introducing covariance representing data stability, so that simple identification of combustion stability of the reciprocating internal combustion engine is realized.
Referring to fig. 2, a flowchart of a method for identifying combustion stability of a reciprocating internal combustion engine according to a second embodiment of the present invention is shown, the method includes steps S101 to S105, wherein:
step S101: the method comprises the steps that a vehicle is in a stable target working condition through a vehicle body electronic stability system ESP;
it can be understood that when the vehicle is running stably, the speed change of the vehicle is relatively gentle, the rotation speed of the crankshaft shared by the engine and the cylinder is also more stable relative to other running stages, so that the error of the acquired information data is smaller, and the slip rate of the wheels and the driving slip rate are required to be controlled within the range of the specified stable region so as to enable the vehicle to be in a stable target working condition.
Step S102: recording the crankshaft rotation speed and ignition signals of each cylinder at intervals of a first preset time by a rotation speed sensor, wherein the first preset time is not less than 10ms, and the data recording duration is not less than 30s;
the engine is provided with a rotating speed sensor, wherein the rotating speed sensor is used for collecting a plurality of circulating working samples during the rotation of a crankshaft, and each circulating working sample comprises the rotating speed of the crankshaft, a preset sampling frequency, ignition signals of each cylinder and recorded duration data;
specifically, the time of the preset sampling frequency is set to be the first preset time, the first preset time is not less than 10ms, the recording duration is not less than 30s, so that the acquired data volume is dense, and the accuracy of the measurement result is higher.
Step S103: converting the crankshaft rotation speed of the engine at the previous moment and the next moment into the crankshaft angular acceleration at the current moment;
it can be understood that the angular acceleration of the crankshaft relative to the rotational speed of the crankshaft can reflect the change of the rotational speed of the crankshaft and accurately judge the stability of the rotational change of the crankshaft in the reciprocating internal combustion engine, so that the rotational speed of the crankshaft needs to be converted into the angular acceleration of the crankshaft;
meanwhile, when the acceleration change rate is relatively gentle, the difference between the front point and the rear point is directly adopted to calculate the acceleration relative to the speed between the adjacent two points, and the calculated acceleration and the actual acceleration error are relatively small, namely the crank angle acceleration at the current moment is obtained according to the crank rotation speed of the engine at the previous moment and the next moment;
specifically, the calculation formula of the conversion is:
wherein: t represents the first preset time period,represents the angular acceleration of the cylinder at the current t moment,/>Representing the engine crankshaft speed at time t+1, < >>Representing the engine crankshaft speed at time t-1.
Step S104: classifying and marking the crank angular acceleration at all moments according to the cylinder ignition signals, wherein the marking result is a cylinder number;
specifically, the cylinders are numbered and ordered according to the working sequence of each cylinder, and all crank angle acceleration data recorded from the starting work of ignition of one cylinder to the starting work of ignition of the next cylinder are programmed under the same number of the current working cylinder to form a crank angle acceleration data set of each cylinder.
Step S105: calculating covariance COV of the angular acceleration of the cylinder corresponding to the cylinder number;
specifically, the covariance COV calculation formula is:
it should also be noted that,average value->。
Step S106: judging the combustion stability of the reciprocating internal combustion engine according to the covariance corresponding to each cylinder;
specifically, judging whether the covariance corresponding to each cylinder is not more than a preset covariance threshold; if the covariance corresponding to each cylinder is not greater than the preset covariance threshold, the combustion stability of each cylinder is indicated;
acquiring a difference value of covariance corresponding to any two cylinders, and judging whether the difference value is smaller than a preset error threshold value or not; if the difference value of covariance corresponding to any two cylinders is smaller than a preset error threshold value, the combustion of each cylinder is consistent;
when the combustion stability of each cylinder is consistent with the combustion stability of each cylinder, the combustion stability of the reciprocating internal combustion engine is judged.
In summary, according to the method for identifying combustion stability of a reciprocating internal combustion engine, by using a rotation speed sensor of the reciprocating internal combustion engine, the combustion stability is determined by avoiding a mode of calculating cylinder pressure by installing a special cylinder pressure sensor, engine crankshaft rotation speed data is more accurate in a direct acquisition mode, crankshaft rotation speed is converted into crankshaft angular acceleration, the stability determination of crankshaft rotation change in the reciprocating internal combustion engine is more accurate and visual, the crankshaft angular acceleration data is numbered and classified according to the working sequence of the cylinders, so that the working condition of each cylinder is easier to locate and check, and the combustion stability of each cylinder and the combustion consistency of each cylinder are determined according to the stability parameters by introducing covariance representing data stability, thereby realizing simple identification of the combustion stability of the reciprocating internal combustion engine.
Referring to fig. 3, a schematic diagram of a system for identifying combustion stability of a reciprocating internal combustion engine according to a third embodiment of the present invention is shown, the system comprising:
the crankshaft signal acquisition module 10 is used for acquiring engine crankshaft rotation speed and cylinder ignition signals of the reciprocating internal combustion engine under a target working condition through the rotation speed sensor 101 at intervals of a first preset time;
the data processing module 20 is configured to convert the obtained crankshaft rotation speed data and classify the converted crankshaft rotation speed data into corresponding cylinder numbers;
further, the data processing module 20 further includes:
a data conversion unit 201, configured to obtain a crank angle acceleration at a current moment according to the engine crank rotation speeds at a previous moment and a next moment;
and the data classification unit 202 is used for classifying and marking the crank angular acceleration at all the moments according to the cylinder ignition signals, and the marking result is a cylinder number.
The analysis and judgment module 30 is used for introducing a calculation parameter representing the stability state to judge the combustion stability of each cylinder and the combustion consistency of each cylinder, and judging the combustion stability of the reciprocating internal combustion engine according to the combustion stability of each cylinder and the combustion consistency of each cylinder;
further, the analysis and judgment module 30 further includes:
a parameter quantization unit 301 for calculating covariance of angular acceleration of a cylinder corresponding to the cylinder number from the plurality of crank angular accelerations under the same cylinder number, respectively;
a determination positioning unit 302 for determining combustion stability of the reciprocating internal combustion engine based on the covariance values respectively corresponding to the cylinders.
In summary, according to the system for identifying combustion stability of a reciprocating internal combustion engine, by using a rotation speed sensor of the reciprocating internal combustion engine, combustion stability is determined by avoiding a mode of calculating cylinder pressure by installing a special cylinder pressure sensor, engine crankshaft rotation speed data is more accurate in a direct acquisition mode, crankshaft rotation speed is converted into crankshaft angular acceleration, stability determination of crankshaft rotation change in the reciprocating internal combustion engine is more accurate and visual, the crankshaft angular acceleration data is numbered and classified according to the working sequence of the cylinders, so that each cylinder working condition is easier to locate and view, and by introducing covariance representing data stability, combustion stability of each cylinder and combustion consistency of each cylinder are determined according to stability parameters, so that simple identification of combustion stability of the reciprocating internal combustion engine is realized.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above examples merely represent a few embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the present invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of the invention should be assessed as that of the appended claims.
Claims (10)
1. A method of identifying combustion stability of a reciprocating internal combustion engine, the method comprising:
acquiring engine crankshaft speed and cylinder ignition signals of the reciprocating internal combustion engine under a target working condition at intervals of a first preset time, wherein the cylinder ignition signals are triggered by a single cylinder in the engine in a power stroke;
traversing the engine crankshaft rotating speeds at all times, and acquiring the crankshaft angular acceleration at the current time according to the engine crankshaft rotating speeds at the previous time and the next time, wherein the crankshaft angular acceleration at any time corresponds to a cylinder of a power stroke at the moment;
classifying and marking the crank angular acceleration at all moments according to the cylinder ignition signals, wherein the marking result is a cylinder number;
and respectively calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number according to a plurality of crank angular acceleration under the same cylinder number, and judging combustion stability of the reciprocating internal combustion engine according to the covariance corresponding to each cylinder.
2. The method of claim 1, wherein the step of acquiring the engine crankshaft speed and the cylinder firing signal of the reciprocating internal combustion engine under the target condition at intervals of the first preset time, wherein the cylinder firing signal is triggered by a single cylinder in the engine during a power stroke, further comprises:
the vehicle body electronic stability system ESP reduces the output torque of the engine and adjusts the braking pressure of wheels to control the posture of the vehicle body, and the slip rate and the driving slip rate of the wheels are controlled within the range of a specified stability area so as to enable the vehicle to be in a stable target working condition.
3. The method of claim 1, wherein the step of acquiring engine crankshaft speed and cylinder firing signals of the reciprocating internal combustion engine at target conditions every first preset time, the cylinder firing signals being triggered by a single cylinder in the engine on a power stroke, further comprises:
and at least acquiring a certain number of circulating working samples through a rotating speed sensor in the combustion process of the cylinder, wherein the recorded data in the circulating working samples comprise the rotating speed of an engine crankshaft, ignition signals of each cylinder and the duration of recorded data, determining that the first preset time is not lower than a preset sampling frequency threshold value, and the duration of the recorded data is not less than a preset recording duration threshold value.
4. The method for identifying combustion stability of a reciprocating internal combustion engine according to claim 1, wherein the step of traversing all engine crankshaft speeds at all times to obtain a current crankshaft angular acceleration from the engine crankshaft speeds at a previous time and a next time, the crankshaft angular acceleration at any time corresponding to a cylinder of a power stroke at the time comprises:
the conversion formula of the step of obtaining the crank angle acceleration at the current moment according to the engine crank rotation speed at the previous moment and the next moment is as follows:
wherein: t represents the first preset time period,represents the angular acceleration of the cylinder at the current t moment,/>Representing the engine crankshaft speed at time t+1, < >>Representing the engine crankshaft speed at time t-1.
5. The method of identifying combustion stability of a reciprocating internal combustion engine according to claim 1, wherein the step of classifying and marking the crank angular acceleration at all times based on the cylinder firing signal as a result of the marking includes:
and sequencing the numbers of the cylinders according to the working sequence of each cylinder, and programming all crank angle acceleration data recorded from the starting work of ignition of one cylinder to the starting work of ignition of the next cylinder into the same number of the current working cylinder to form a crank angle acceleration data set of each cylinder.
6. The method of recognizing combustion stability of a reciprocating internal combustion engine according to claim 1, wherein the step of calculating covariance of angular acceleration of cylinders corresponding to the cylinder numbers from the plurality of crank angular accelerations under the same cylinder number, respectively, and judging combustion stability of a reciprocating internal combustion engine from the covariance corresponding to each cylinder, respectively, comprises:
a covariance COV representing the steady state of the data was introduced to characterize the combustion stability of the engine, which was calculated as follows:
average value->。
7. The method of recognizing combustion stability of a reciprocating internal combustion engine according to claim 6, wherein the step of calculating covariance of angular acceleration of cylinders corresponding to the cylinder numbers from the plurality of crank angular accelerations under the same cylinder number, respectively, and judging combustion stability of a reciprocating internal combustion engine from the covariance corresponding to each cylinder, respectively, comprises:
judging whether the covariance corresponding to each cylinder is not more than a preset covariance threshold; if the covariance corresponding to each cylinder is not greater than the preset covariance threshold, the combustion stability of each cylinder is indicated;
acquiring a difference value of covariance corresponding to any two cylinders, and judging whether the difference value is smaller than a preset error threshold value or not; if the difference value of covariance corresponding to any two cylinders is smaller than a preset error threshold value, the combustion of each cylinder is consistent;
when the combustion stability of each cylinder is consistent with the combustion stability of each cylinder, the combustion stability of the reciprocating internal combustion engine is judged.
8. A system for identifying combustion stability of a reciprocating internal combustion engine, the system comprising:
the crankshaft signal acquisition module is used for acquiring engine crankshaft rotation speed and cylinder ignition signals of the reciprocating internal combustion engine under a target working condition through the rotation speed sensor at intervals of a first preset time;
wherein, bent axle signal acquisition module includes:
the rotating speed sensor is used for testing and acquiring the rotating speed of a crankshaft, a preset sampling frequency, a cylinder ignition signal and preset recording duration data when the reciprocating internal combustion engine burns;
the data processing module is used for converting the acquired crankshaft rotation speed data and classifying the converted crankshaft rotation speed data into corresponding cylinder numbers;
the analysis judging module is used for introducing a calculated parameter representing the stability state to judge the combustion stability of each cylinder and the combustion consistency of each cylinder, and judging the combustion stability of the reciprocating internal combustion engine according to the combustion stability of each cylinder and the combustion consistency of each cylinder.
9. The system for identifying combustion stability of a reciprocating internal combustion engine of claim 8, wherein the data processing module further comprises:
the data conversion unit is used for acquiring the crank angle acceleration at the current moment according to the crank rotation speeds at the previous moment and the next moment;
and the data classification unit is used for classifying and marking the crank angular acceleration at all moments according to the cylinder ignition signals, and the marking result is a cylinder number.
10. The system for identifying combustion stability of a reciprocating internal combustion engine of claim 8, wherein the analysis and determination module further comprises:
a parameter quantization unit for calculating covariance of angular acceleration of the cylinder corresponding to the cylinder number according to a plurality of crank angular acceleration under the same cylinder number;
and the judging and positioning unit is used for judging the combustion stability of the reciprocating internal combustion engine according to the covariance corresponding to each cylinder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311106057.5A CN116816497B (en) | 2023-08-30 | 2023-08-30 | Method and system for identifying combustion stability of reciprocating internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311106057.5A CN116816497B (en) | 2023-08-30 | 2023-08-30 | Method and system for identifying combustion stability of reciprocating internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116816497A true CN116816497A (en) | 2023-09-29 |
| CN116816497B CN116816497B (en) | 2023-11-17 |
Family
ID=88118869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311106057.5A Active CN116816497B (en) | 2023-08-30 | 2023-08-30 | Method and system for identifying combustion stability of reciprocating internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116816497B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5687692A (en) * | 1993-12-21 | 1997-11-18 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Combustion state determination method of internal combustion engine, as well as combustion state control method and combustion state control system for internal combustion engine |
| US6305352B1 (en) * | 1997-09-05 | 2001-10-23 | Renault | Method for detecting an abnormal disturbance of an internal combustion engine torque |
| CN102072818A (en) * | 2010-11-09 | 2011-05-25 | 联合汽车电子有限公司 | Method for obtaining fire detection signal of cylinder of engine with speed sensor arranged in front |
| US20160146702A1 (en) * | 2014-11-26 | 2016-05-26 | Hyundai Motor Company | Method for detecting surge level in vehicle |
| CN113642204A (en) * | 2021-07-06 | 2021-11-12 | 江苏大学 | Method for correcting combustion starting point identification deviation based on combustion excitation contribution degree |
| CN115186501A (en) * | 2022-07-26 | 2022-10-14 | 湖南华研实验室有限公司 | Method for evaluating stability of combustion process of internal combustion engine |
-
2023
- 2023-08-30 CN CN202311106057.5A patent/CN116816497B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5687692A (en) * | 1993-12-21 | 1997-11-18 | Mitsubishi Jidosha Kogyo Kabushiki Kaisha | Combustion state determination method of internal combustion engine, as well as combustion state control method and combustion state control system for internal combustion engine |
| US6305352B1 (en) * | 1997-09-05 | 2001-10-23 | Renault | Method for detecting an abnormal disturbance of an internal combustion engine torque |
| CN102072818A (en) * | 2010-11-09 | 2011-05-25 | 联合汽车电子有限公司 | Method for obtaining fire detection signal of cylinder of engine with speed sensor arranged in front |
| US20160146702A1 (en) * | 2014-11-26 | 2016-05-26 | Hyundai Motor Company | Method for detecting surge level in vehicle |
| CN106198032A (en) * | 2014-11-26 | 2016-12-07 | 现代自动车株式会社 | For the method detecting the impact-level in vehicle |
| CN113642204A (en) * | 2021-07-06 | 2021-11-12 | 江苏大学 | Method for correcting combustion starting point identification deviation based on combustion excitation contribution degree |
| CN115186501A (en) * | 2022-07-26 | 2022-10-14 | 湖南华研实验室有限公司 | Method for evaluating stability of combustion process of internal combustion engine |
Non-Patent Citations (1)
| Title |
|---|
| 王洪强: "基于曲轴角加速度评价发动机燃烧均匀性的方法研究", 中国优秀硕士论文电子期刊网 工程科技Ⅱ辑, pages 035 - 46 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116816497B (en) | 2023-11-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5485374A (en) | Combustion-conditon diagnostic system and method for a multicylinder engine | |
| US5041980A (en) | Method and apparatus for producing fault signals responsive to malfunctions in individual engine cylinders | |
| CN100476182C (en) | Misfire detection apparatus | |
| CN102066729A (en) | Fuel system diagnostics by analyzing engine cylinder pressure signal and crankshaft speed signal | |
| US7610800B2 (en) | Method and system for collecting crankshaft position data | |
| US6314802B1 (en) | Optimal engine speed compensation method used in misfire detection | |
| CN103443426A (en) | Method for diagnosing a supercharging system of internal combustion engines | |
| US6729186B1 (en) | Multi-channel vibration analyzer | |
| US20090276138A1 (en) | Time and angle based cylinder pressure data collection | |
| CN111140354B (en) | Method and device for detecting fire of whole vehicle | |
| KR101792177B1 (en) | Method for estimating a torque generated by an internal combustion engine | |
| CN116816497B (en) | Method and system for identifying combustion stability of reciprocating internal combustion engine | |
| US20100063674A1 (en) | Engine test method using structured test protocol | |
| CN112668419B (en) | Engine emission prediction method based on vibration signal | |
| US20050027403A1 (en) | Parameter identification-based filtering | |
| CN115467752B (en) | Method, system and computer storage medium for diagnosing and analyzing fire of automobile engine | |
| CN112343712B (en) | Sensitivity analysis method for engine suspension vibration | |
| CN112666925B (en) | Diesel engine vehicle-mounted diagnosis system and diagnosis method thereof | |
| CN114659794A (en) | Engine detection platform and engine offline detection method | |
| JPH08312445A (en) | Discriminating method of misfire during combustion | |
| US11421587B2 (en) | Method and system for diagnosing and/or controlling a reciprocating engine having a variable compression ratio | |
| CN112267998A (en) | Method for testing highest temperature in cylinder and nonuniformity of cylinders of multi-cylinder diesel engine | |
| US7203592B2 (en) | Method for detecting failed combustion in an internal combustion engine by a combination of combustion irregularity indices | |
| CN112161810B (en) | Method, device, equipment and medium for detecting power of automobile engine | |
| CN112319495B (en) | Method, device and equipment for determining automobile system model and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |