Diesel oil beam drop point position dynamic detection method, device and medium

Abstract

The invention provides a diesel oil beam drop point position dynamic detection method and device and a medium, belongs to the technical field of internal combustion engine fuel injection detection, and aims at a petal-shaped combustion chamber, micro pressure sensors are reasonably arranged on the inner surface of the petal-shaped combustion chamber to form a detection grid, and the target oil beam drop point position is determined according to parameters of an oil injector. A pressure sensor signal is collected and preprocessed, an oil beam impact pressure field is constructed, and coordinates of a high-pressure area are extracted from the oil beam impact pressure field to calculate the actual oil beam drop point position. And comparing the actual drop point position with the target position to obtain a deviation, and finally averaging the deviation of the plurality of oil beam drop point positions to obtain an average oil beam deviation. By arranging the sensor, oil beam drop point information can be accurately obtained, and the deviation condition between the actual oil beam drop point and a target is mastered. Under the complex working condition of the engine, oil beam injection abnormity can be found in time, and reliable basis is provided for improving engine performance and stability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of internal combustion engine fuel injection detection, and particularly relates to a diesel oil jet drop point position dynamic detection method, device and medium. BACKGROUND

[0002] The design goal of the petal-shaped combustion chamber is to spray the oil jet sprayed from the oil injector between the two petals to achieve the best air utilization rate and combustion characteristics. However, in actual engineering application, the diesel engine is mainly vortex, and the air will form a strong vortex airflow in the combustion chamber, which will cause the oil jet sprayed from the oil injector to rotate a certain angle under the action of the airflow, deviating from the design goal, affecting the oil-gas mixing characteristics and combustion characteristics.

[0003] In related technologies, a pressure sensor needs to be set, which is set on the petal protrusion of the petal-shaped combustion chamber or randomly placed, so that the main area impacted by the oil jet is blocked by the protrusion, and the sensor cannot capture the effective pressure signal.

[0004] In related technologies, the target oil jet drop point is set according to the past use mode, and since the parameters such as the injection pressure and the hole diameter of the oil injector are not associated, these parameters directly affect the oil jet range and the diffusion angle, so that the target drop point does not match the actual oil injection state, causing large detection deviation.

[0005] In related technologies, the oil jet position is determined based on the pressure value of the sensor, and since there is a time difference from injection to impact in the process of oil jet impact, the pressure decays over time, and a certain pressure value cannot reflect the overall distribution of the impact area, so that the edge low pressure point is easily misjudged as the drop point, resulting in low positioning accuracy. SUMMARY

[0006] The present application provides a diesel oil jet drop point position dynamic detection method, which is used to realize the best oil-gas mixing characteristics and combustion characteristics of diesel and air, arrange ring array pressure sensors on the inner surface of the combustion chamber, collect the pressure of each pressure sensor in real time under complex engine working conditions, construct the oil jet impact pressure field in the combustion chamber, calculate the center position and diffusion range of the oil jet drop point, and provide the direction for subsequent accurate matching of the diesel oil jet and the combustion chamber.

[0007] The method comprises the following steps: S101: According to the number of petals of the combustion chamber, an initial position is determined at the center of the oil jet injection area between every two adjacent petals, and according to the injection pressure and the hole diameter of the oil injector, a target oil jet drop point position is determined between every two petals, and the target oil jet drop point position corresponds to the initial position; S102: A plurality of micro pressure sensors are arranged on the inner surface of the petal-shaped combustion chamber to form a detection grid avoiding the petal protrusion; S103: Collect the pressure signals of each pressure sensor, and use the signal processing module to pre-process the pressure signals to eliminate high-frequency interference signals; S104: According to the position coordinates of each pressure sensor and the pre-processed pressure signals, combined with the space-time distribution characteristics of the pressure signals, the oil jet impact pressure field in the combustion chamber is constructed; S105: From the oil jet impact pressure field constructed in S104, the pressure field region coordinates with a pressure value not lower than a preset pressure value are extracted, and the actual landing point position of each oil jet is calculated based on the pressure field region coordinates; S106: Compare the actual oil jet landing point position calculated in S105 with the target oil jet landing point position determined in S102, and calculate the landing point position deviation of each oil jet; S107: Average value calculation is performed on the multiple oil jet landing point position deviations obtained in S106 to obtain the average oil jet deviation.

[0008] According to another embodiment of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the diesel oil jet landing point position dynamic detection method when executing the program.

[0009] According to another embodiment of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the diesel oil jet landing point position dynamic detection method when executing the program.

[0010] From the above technical solutions, the present application has the following advantages: The diesel oil jet landing point position dynamic detection method of the present application arranges sensors in the petal gap and avoids the petal protrusions, avoids physical shielding of the protrusions to the pressure signals, forms a regular detection grid, ensures that there is no detection blind area in the oil jet impact area, and improves the integrity of signal acquisition. The target landing point is determined in combination with the injection pressure and aperture of the oil injector, so that the target position is bound to the physical characteristics of the oil injection. Synchronous acquisition and high-frequency noise reduction processing eliminate the influence of noise such as electromagnetic interference and sensor vibration on the pressure signals, ensure that the signals for constructing the input pressure field truly reflect the oil jet impact characteristics, and improve the data reliability. Based on the space-time distribution characteristics, the pressure field is constructed to completely present the three-dimensional space pressure distribution and time-varying law of the oil jet impact, provide field information for landing point extraction, extract the maximum pressure region and weightedly calculate the actual landing point, and improve the positioning accuracy of the actual landing point. Three-dimensional direction deviation decomposition clearly shows the offset direction and size of the oil jet in the circumferential and axial directions, and provides a quantitative basis for analyzing the deviation causes. The average deviation is calculated according to the working conditions, the accidental error of single oil jet and single measurement is eliminated, and the overall level of oil jet control under complex working conditions is comprehensively reflected. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the present application, the drawings needed to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description only represent some embodiments of the present application, and all other drawings obtained by those skilled in the art without any creative effort based on the drawings also belong to the protection scope of the present application.

[0012] Figure 1 Flow chart of diesel oil beam landing position dynamic detection method; Figure 2 Schematic diagram of petal-shaped combustion chamber and pressure sensor array; Figure 3 Schematic diagram of pressure sensor collecting established oil beam pressure impact field; Figure 4 Schematic diagram of electronic device. DETAILED DESCRIPTION

[0013] The diesel oil beam landing position dynamic detection method related to the present application will be described in detail as follows. In order to illustrate but not to limit, specific details such as specific system structures, techniques, etc. are presented in order to thoroughly understand the embodiments of the present application. However, those skilled in the art should understand that the present application can also be implemented in other embodiments without these specific details.

[0014] It should be understood that when used in the specification of the present application, the term "comprising" indicates the existence of described features, integers, steps, operations, elements and / or components, but does not exclude the existence or addition of one or more other features, integers, steps, operations, elements, components and / or sets thereof. The terms "comprise", "include", "have" and their variants mean "including but not limited to", unless otherwise specifically emphasized.

[0015] The phrase "one embodiment" or "some embodiments" or similar phrases appearing in the present application means that the specific feature, structure or characteristic described in the embodiment is included in one or more embodiments of the present application. Therefore, the phrases "in one embodiment", "in some embodiments", "in other some embodiments", "in further some embodiments" appearing in different places in the present application do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized.

[0016] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort also belong to the protection scope of the present application.

[0017] Referring to Figure 1 FIG. 1 shows a flowchart of a method for dynamically detecting the diesel fuel spray impingement position in an embodiment, the method comprising: S101: According to the number of petals of the combustion chamber, an initial position is determined at the center of the fuel spray injection area between every two adjacent petals. According to the injection pressure and nozzle diameter of the fuel injector, a target fuel spray impingement position is determined between every two petals, which corresponds to the initial position.

[0018] It should be noted that according to the number of petals of the combustion chamber, an initial position is determined at the center of the fuel spray injection area between every two adjacent petals. Exemplarily, if the number of petals is 6, 6 initial positions are set. The coordinates of the initial positions are defined as W i0 (X i0 , Y i0 , Z i0 ), where i is the number of petals. The coordinates are calculated based on the three-dimensional geometric model of the combustion chamber, determined by the geometric center point or simulation, to ensure that each initial position is located at the ideal center of the fuel spray injection area. If the number of petals of the combustion chamber is 6, 6 initial positions are determined, which are W 01 ~W 06 .

[0019] In this embodiment, the center of the piston top surface is taken as the coordinate origin (0, 0, 0), the rear end direction of the engine crankshaft axis is defined as the +X axis, the direction of the piston secondary thrust side is defined as the +Y axis, and the direction perpendicular to the piston top surface is defined as the +Z axis. This coordinate system is used to unify the reference of all position coordinates.

[0020] The coordinates of the initial positions W i0 Based on the coordinates of the boundary points of the petals, the center point between every two petals is calculated. For example, for the boundary points (X1, Y1, Z1) and (X2, Y2, Z2) of adjacent petals, the coordinates of the initial position can be calculated as: Xi0 = (X1+ X2) / 2; Yi0 = (Y1 + Y2) / 2; Zi0 = (Z1 + Z2) / 2. The initial position avoids the protruding area of the petals to avoid interference.

[0021] In some embodiments, based on the injection pressure and nozzle diameter of the fuel injector, combined with the design parameters such as the size of the combustion chamber of the engine and the installation angle of the fuel injector, the target fuel spray impingement position under each operating condition is determined through simulation. Each target impingement position corresponds to the initial position of the same fuel spray injection area in S101, forming a one-to-one spatial correlation.

[0022] In this way, the injection pressure and the hole diameter of the oil injector directly affect the range and the diffusion angle of the oil jet, and in combination with the structure of the combustion chamber, the target landing point to which the oil jet should reach can be preset as a benchmark for evaluating the deviation of the actual landing point.

[0023] S102: A plurality of micro pressure sensors are arranged on the inner surface of the petal-shaped combustion chamber to form a detection grid avoiding the petal protrusions.

[0024] In some embodiments, as shown in Figure 2 , Figure 2 , a petal-shaped combustion chamber 1, i petals 2, an oil jet injection area 3 separated by petals, and a plurality of pressure sensors are arranged.

[0025] Among them, the first pressure sensor 4 is arranged at the first initial position W 10 , the second pressure sensor 5 is arranged at the second initial position W 20 , the third pressure sensor 6 is arranged at the second initial position W 30 , the fourth pressure sensor 7 is arranged at the second initial position W 40 , the fifth pressure sensor 8 is arranged at the second initial position W 50 , the sixth pressure sensor 9 is arranged at the second initial position W 60 , and the remaining pressure sensor 10 is arranged at the initial position W 1j .

[0026] It should be noted that M×N micro pressure sensors are arranged on the inner surface of the combustion chamber. They are arranged uniformly in a circular array to form a detection grid. The number of sensors can be dynamically adjusted according to the number of petals of the combustion chamber.

[0027] Among them, as shown in Figure 3 , the number of petals of the unconventional petal combustion chamber can be set to 6-8, and correspondingly, the number of oil injector holes corresponds to the number of petals, which is also 6-8. An oil jet injection area is formed between every two petals. The center of the top surface of the piston is defined as the origin (0, 0, 0), the rear end of the engine crankshaft axis is defined as the +X axis, and the +Y axis is defined as the side of the piston. The initial position is taken as the center and arranged uniformly along the circumferential direction with an interval of 3mm, and no pressure sensor is arranged at the petal protrusion. Finally, the circumferential direction pressure sensors arranged in the above step are taken as the benchmark, and the same number of pressure sensors are arranged in the axial direction with an interval of 3mm. The limit range in the axial direction is the start and end surfaces of the petals. Except for the initial position, the coordinates of the remaining pressure sensor positions are defined as W ij (X ij , Y ij , Z ij ). The petal position is recorded in the pressure sensor coordinates. Thus, a pressure sensor detection grid is formed on the surface of the combustion chamber.

[0028] The embodiment forms a three-dimensional detection grid in the area where the oil jet may be sprayed by regularly arranging the sensors, ensuring that the pressure signal when the oil jet impacts can be captured by the sensors, while avoiding the physical interference of the petal protrusions.

[0029] S103: Collect the pressure signals of each pressure sensor, and use the signal processing module to pre-process the pressure signals to eliminate high-frequency interference signals.

[0030] In some embodiments, real-time pressure signals of all sensors are collected. The preprocessing includes filtering, which filters out high-frequency noise generated by electromagnetic interference, sensor vibration, etc. by decomposing the signal into different frequency scales, and retains the effective pressure signal generated by the oil jet impact, ensuring the authenticity of the signal.

[0031] S104: According to the position coordinates of each pressure sensor and the pre-processed pressure signals, combined with the spatio-temporal distribution characteristics of the pressure signals, the oil jet impact pressure field in the combustion chamber is constructed.

[0032] In some embodiments, the sensor coordinates (X, Y, Z) are associated with the corresponding pre-processed pressure signals to form a spatio-temporal data set. An interpolation algorithm is used to estimate the pressure values at positions in the combustion chamber space where sensors are not arranged based on the pressure values of the discrete sensors. Combined with the spatio-temporal characteristics of the pressure signals based on the time of occurrence of the pressure peak value and the decay law of the pressure with time, the oil jet impact pressure field is constructed.

[0033] As can be seen, the pressure of the oil jet impact is continuously distributed in the combustion chamber space, and the detection results of the discrete sensors can be extended to a continuous pressure field through interpolation, and the spatio-temporal characteristics reflect the dynamic process of the oil jet impact.

[0034] S105: From the oil jet impact pressure field constructed in S104, the pressure field region coordinates with pressure values not lower than the preset pressure value are extracted, and the actual landing position of each oil jet is calculated based on the pressure field region coordinates.

[0035] In some embodiments, during the time period of the oil jet impact, the maximum pressure value Pmax in the pressure field is determined; the oil jet impact region with a pressure ≥90% Pmax is selected, and the coordinates of all points in the region are recorded. The actual landing position of the oil jet is obtained by weighted averaging of the X, Y, and Z coordinates with the pressure values of the points as weights.

[0036] Optionally, S105 further comprises the following steps: according to the constructed pressure field, extracting the pressure field region coordinates with pressure P greater than or equal to 90% Pmax in the middle of each two petals; according to the extracted pressure field region coordinates, respectively calculating the X-direction position Xi = ∑(Pi * Xij) / Pi, the Y-direction position Yi = ∑(Pi * Yij) / Pi, and the Z-direction position Zi = ∑(Pi * Zij) / Pi; and obtaining the measured actual oil jet landing point position Wi corresponding to the number of oil jets.

[0037] As can be seen, the embodiment is based on the highest pressure in the region impacted by the oil jet. Close to Pmax, the central position of the region can represent the actual landing point of the oil jet; and the weighted average makes the points with higher pressure have greater influence on the calculation of the landing point, which is more in line with the physical characteristics of the oil jet impact.

[0038] S106: comparing the actual oil jet landing point position calculated by S105 with the target oil jet landing point position determined by S102, and calculating the landing point position deviation of each oil jet.

[0039] In some embodiments, for each oil jet, the coordinate difference between the actual landing point and the target landing point in the X, Y, and Z axis directions is calculated respectively. Optionally, ΔX = actual X - target X, ΔY = actual Y - target Y, and ΔZ = actual Z - target Z. The size and direction of the deviation are recorded, and the positive / negative value represents the deviation direction, forming a three-dimensional deviation vector of each oil jet.

[0040] In this way, the spatial deviation between the actual landing point and the target landing point is quantified by the coordinate difference, and the three-dimensional decomposition can clearly show the specific performance of the deviation in different directions.

[0041] In some specific embodiments, S106 specifically comprises the following steps: S1061: establishing a correspondence between the actual and target oil jet landing points according to the oil jet injection zone number.

[0042] In this embodiment, each actual oil jet landing point position Wi obtained by step S105 is associated with the corresponding target oil jet landing point position Ti obtained by step S102 according to the oil jet injection zone number i = 1, 2, …, 6 ~ 8 divided by step S101, so as to ensure that the same number corresponds to the landing point of the same oil jet injection zone.

[0043] In some embodiments, the oil jet injection zone number is consistent with the sensor coordinate partition number in step S101 and the target oil jet landing point number in step S102, and the numbering rule is to arrange the numbers in a preset order starting from the +X axis positive direction along the circumferential direction of the combustion chamber, so as to ensure that each number uniquely corresponds to an oil jet injection zone.

[0044] S1062: For each associated Wi (Xi, Yi, Zi) and Ti (Xti, Yti, Zi), calculate the X-axis deviation ΔXi, Y-axis deviation ΔYi, and Z-axis deviation ΔZi, respectively, where Xi, Yi, Zi are the actual landing point coordinates, and Xti, Yti, Zi are the target landing point coordinates.

[0045] In some embodiments, ΔXi = Xi - Xti, ΔYi = Yi - Yti, and ΔZi = Zi - Zti.

[0046] Here, Xi, Yi, Zi are taken from the coordinates of the actual oil beam landing point position Wi that passes the verification, and Xti, Yti, Zi are taken from the coordinates of the associated target oil beam landing point position Ti; all coordinate values are based on the same combustion chamber space coordinate system established.

[0047] S1063: Combine ΔXi, ΔYi, and ΔZi calculated in step S1062 into a three-dimensional deviation vector ΔWi for the oil beam, and record the oil beam number, engine operating condition parameters, and measurement time difference corresponding to the deviation vector.

[0048] In some embodiments, the deviation vector expression is: ΔWi = (ΔXi, ΔYi, ΔZi) (i = 1, 2, …, 6 ~ 8). This embodiment characterizes the three-dimensional deviation state of a single oil beam landing point in vector form, and associates it with the operating condition and time information at the time of measurement, forming a deviation data set.

[0049] S1064: Pre-set a reasonable range threshold Dlim for each axis deviation, which is determined based on the geometry of the combustion chamber and the accuracy of the oil injection system. For each deviation vector ΔWi, determine whether ΔXi, ΔYi, and ΔZi are within the range [-Dlim, Dlim], and retain ΔWi as valid deviation data if all axis deviations are within the reasonable range.

[0050] In some embodiments, the screening condition is: |ΔXi| ≤ Dlim, |ΔYi| ≤ Dlim, |ΔZi| ≤ Dlim, Dlim: reasonable deviation range threshold, with a value of 3 ~ 8 mm, such as 6-petal combustion chamber with a petal spacing of about 15 mm, and Dlim = 5 mm.

[0051] It should be noted that the determination of Dlim is based on the maximum allowed oil beam deviation of the engine combustion chamber, which is usually not more than 8 mm, and exceeding it may lead to incomplete combustion. If an axis deviation exceeds [-Dlim, Dlim], the deviation vector ΔWi is determined as abnormal data, and the actual landing point calculation in step S105 or the target landing point determination in step S102 is checked back to exclude data errors and recalculate to ensure data validity.

[0052] S1065: Repeat the collection of 3-5 effective deviation data under the same engine operating condition, calculate the standard deviation of each axial effective deviation of each oil jet, if the standard deviation is less than or equal to σlim, it is determined that the deviation data of the oil jet meets the time domain stability requirement, and the deviation data is retained; otherwise, re-measure the deviation.

[0053] In some embodiments, the repeated measurements are continuously performed under the same condition, ΔXavg, ΔYavg, and ΔZavg are the arithmetic mean values of the axial deviations in m measurements, respectively; if the standard deviation of a certain axis exceeds σlim, check the fastening state and grounding condition of the pressure sensor, and re-measure after excluding the interference.

[0054] In this way, the time domain fluctuation degree of the deviation data is judged by the standard deviation of multiple repeated measurements, and the smaller the fluctuation is, the smaller the deviation affected by random interference is, the more stable the data is, and the more it can reflect the real working condition deviation of the engine.

[0055] S107: Calculate the average value of the multiple oil jet landing position deviations obtained in S106 to obtain the average oil jet deviation.

[0056] In some embodiments, the ΔX, ΔY, and ΔZ of all oil jets under each group condition are calculated according to the engine speed and load, and the average value is weighted according to the importance of the oil jet, such as the oil jet near the spark plug with higher weight, and the sample size of each group is ≥3 repeated measurements to reduce the influence of random error.

[0057] In some specific embodiments, S107 specifically includes the following steps: S1071: Group the effective deviation data that passes the time domain stability check according to the speed n and the load L, and mark each group as a working condition (n0, L0), wherein n0 is the average speed in the group, and L0 is the average load in the group; each group of data includes the three-dimensional deviation vector ΔWi of all oil jets under the working condition.

[0058] In some embodiments, the speed grouping is based on the engine idle speed of 600-800 r / min, medium speed of 1500-2500 r / min, and high speed of 3000-4000 r / min, and the load is divided according to the 20% rated load increment. A single data is classified into the group closest to its n and L, ensuring that each group of data corresponds to a stable working condition.

[0059] S1072: For each group of working conditions, set the weight according to the physical distance between the oil jet injection area and the spark plug and the injector axis of the combustion chamber, and weight average ΔXi, ΔYi, and ΔZi of each oil jet to obtain the average deviation ΔX, ΔY, and ΔZ under the working condition.

[0060] In some embodiments, the weight is determined by combustion simulation, such as setting the weight of the oil jet area close to the spark plug to 1.2 and setting the weight of the area far away from the key area to 1.0.

[0061] In the weighted average of the present embodiment, the effective deviation data passing the stability check is used, and the abnormal values are not included. It can be seen that different oil jets have different physical effects on combustion performance, and the weight distribution makes the oil jet deviation that is more critical to combustion have a higher proportion in the average result, which conforms to the priority of the key area.

[0062] S1073: From the pressure field constructed in S104, the pressure peak coordinates (Xp, Yp, Zp) of each oil jet area under each group of working conditions are extracted, and the deviation from the target landing point Ti is calculated, wherein ΔXp=Xp-Xti, ΔYp=Yp-Yti, ΔZp=Zp-Zti; If the absolute difference values of the average deviations ΔX, ΔY, ΔZ and the corresponding pressure peak deviations ΔXp, ΔYp, ΔZp are all ≤ the preset pressure difference threshold, it passes the check; otherwise, the oil jet data with the largest deviation difference under the working condition is removed, the average deviation is recalculated, and the check is performed.

[0063] In some embodiments, the pressure peak coordinates (Xp, Yp, Zp) are extracted from the pressure field constructed in step S104, and are limited within the oil jet impact time period. The preset pressure deviation threshold can be 0.8 mm, and of course the difference threshold can be set based on the physical law of oil jet impact and calibrated by bench test.

[0064] S1074: For each oil jet area under each group of working conditions, the oil jet deviations detected by the three adjacent pressure sensors are selected, and the spatial gradient of the adjacent deviations is calculated. If all the spatial gradients are ≤0.3 mm / mm, and the difference between the average deviation of the oil jet and the average deviation of the adjacent sensor is ≤1 mm, it passes the check; otherwise, the sensor data in the area is supplemented and recalculated.

[0065] Alternatively, the spatial gradient ΔXgradient=|ΔX2-ΔX1| / sensor spacing, and the spacing is 3 mm. The three nearest adjacent sensors to the target oil jet area are selected according to the coordinate partitioning in step S101. The sensor spacing in the spatial gradient calculation is 3 mm, that is, the arrangement interval in step S101. The gradient threshold of 0.3 mm / mm is set based on the continuity of the oil jet impact, and the deviation will not suddenly change within the adjacent 3 mm.

[0066] The present embodiment uses the spatial distribution characteristics of the sensor to constrain the data dispersion, and ensures the rationality of the deviation in the physical space.

[0067] S1075: Sensitivity verification of engine operating parameter is performed. The average deviation of three adjacent speeds under the same load is verified to see whether the change trend is consistent with the increase of speed and the increase of ΔX / ΔY, and the deviation increment of adjacent speeds is in the interval of 0.1-0.5 mm / 500 r / min; The average deviation of three adjacent loads under the same speed is verified to see whether the change trend is consistent with the increase of load and the decrease of ΔZ, and the deviation decrement of adjacent loads is in the interval of 0.1-0.4 mm / 20% load; after all trend verifications, an average deviation correlation report is generated.

[0068] It should be noted that the interval of adjacent speeds is 500 r / min, and the interval of adjacent loads is 20% of the rated load, covering the main operating range of the engine. The increment / decrement interval in trend verification is calibrated through injection system dynamics simulation to ensure compliance with physical laws.

[0069] The oil jet deviation is affected by speed and injection pressure load, and its change trend should be consistent with the action law of these factors. Abnormal trend indicates that the data may be disturbed by operating condition fluctuations. Through physical correlation verification of operating parameters and deviation, it is ensured that the average deviation can reflect the real operating condition characteristics of the engine.

[0070] In an embodiment of the present application, based on step S102, a possible embodiment will be given below to illustrate the specific implementation of the embodiment. S102 specifically includes the following steps: S1021: Establish a combustion chamber space coordinate system and determine the number of initial positions.

[0071] In some embodiments, the center of the piston top surface is taken as the origin (0, 0, 0), the rear end of the engine crankshaft axis is taken as the +X axis, the piston secondary thrust side is taken as the +Y axis, and the piston axis direction is taken as the +Z axis; according to the number i of petals of the combustion chamber, the number of initial positions in the middle of each two petals is determined as i.

[0072] S1022: Determine the coordinates of each initial position.

[0073] In this embodiment, each initial position is numbered as Wi0, and the coordinates are determined as Wi0(Xi0, Yi0, Zi0), respectively.

[0074] In some embodiments, each initial position corresponds to the center region of the oil jet injection area in the middle of "two petals", and the coordinate value is determined according to the petal position of the combustion chamber, the piston height, etc. It is ensured that each oil jet injection area has a corresponding initial detection reference point, improving the pertinence of oil jet landing point detection and the rationality of regional coverage.

[0075] S1023: Arrange pressure sensors in the circumferential direction.

[0076] The embodiment is arranged with pressure sensors in the circumferential direction, with each initial position Wi0 as the center, and the sensors are arranged uniformly with a 3mm interval, and no sensor is arranged at the petal protrusion. With the initial position Wi0 as the center, a sensor is arranged every 3mm in the circumferential direction, and the physical obstacle area of the petal protrusion is avoided. The detection resolution of the oil beam landing point in the circumferential direction is improved, and the spatial accuracy of detection is enhanced even if the oil beam has a slight deviation in the circumferential direction.

[0077] S1024: The pressure sensors are arranged in the axial direction.

[0078] The embodiment is arranged with pressure sensors in the circumferential direction, with each initial position Wi0 as the center, and the sensors are arranged uniformly with a 3mm interval, and no sensor is arranged at the petal protrusion. With the initial position Wi0 as the center, a sensor is arranged every 3mm in the circumferential direction, and the physical obstacle area of the petal protrusion is avoided. The detection resolution of the oil beam landing point in the circumferential direction is improved, and the spatial accuracy of detection is enhanced even if the oil beam has a slight deviation in the circumferential direction.

[0079] S1025: Record the pressure sensor coordinates according to the petal position.

[0080] The embodiment records the coordinates Wij(Xij, Yij, Zij) of the remaining pressure sensors except the initial position according to the petal area where the pressure sensor is located, and each petal area corresponds to a group of sensor coordinates. According to the spatial position of the petals, the coordinates Wij(Xij, Yij, Zij) of all sensors are divided into i regions, each region corresponds to an interval of the petals, and the pressure signal can be directly corresponded to the landing point analysis of a specific oil beam.

[0081] In an embodiment of the present application, based on step S101, a possible embodiment will be given below to illustrate the specific implementation scheme. S101 specifically includes the following steps: Step S1011: Use high-precision pressure sensors and flow meters to measure the injection pressure, injection hole diameter and unit time injection amount of the oil injector on a standard test bench, establish an injection pressure-injection amount relationship curve, and record the corresponding relationship between the number of injection holes and the number of petals in the combustion chamber, to ensure that each injection hole corresponds to an oil beam injection area.

[0082] In the parameter acquisition of the oil injector, the embodiment uses a laser vibration meter to calibrate the pressure sensor, uses a weighing method to calibrate the injection amount, takes an average value by repeating the measurement 8 times to reduce random errors. The relative position of the injection hole and the petal in the combustion chamber is determined by a three-dimensional coordinate measuring instrument to ensure that the number of holes and the number of petals correspond one by one.

[0083] Step S1012: Based on the principle of fluid mechanics, combined with the injection parameters of the oil injector, a motion trajectory model of the oil beam in the combustion chamber is constructed.

[0084] The motion trajectory model of the embodiment considers the influence of the initial injection speed, the oil jet diffusion angle, the air resistance and the combustion chamber airflow field, and calculates the motion path of the oil jet from the oil injection hole to the combustion chamber wall surface through numerical simulation or an empirical formula.

[0085] It should be noted that the oil jet trajectory modeling is simulated by using computational fluid dynamics (CFD) software to capture the turbulent details of the oil jet edge. The Rosin-Rammler distribution is combined to describe the oil jet particle size distribution, thereby improving the prediction accuracy of the model for the actual oil jet diffusion.

[0086] Step S1013: According to the oil jet trajectory model, the expected landing point coordinates of the oil jet between each two petals of the combustion chamber are calculated in combination with the geometric positions of the petals. In the specific calculation, the position of the oil injection hole is taken as the starting point, the oil jet trajectory is extended to the combustion chamber surface, and the landing point Ti (Xti, Yti, Zti) corresponding to the initial position Wi0 is determined.

[0087] In the calculation of the target landing point coordinates, the micro-topography of the combustion chamber surface is considered, the pressure distribution of the oil jet when impacting the combustion chamber wall surface is determined through finite element analysis, and the landing point position is then back calculated; the Monte Carlo method is used to simulate the randomness of the oil jet trajectory, and the statistical average of the landing point coordinates is given.

[0088] Step S1014: The target landing point coordinates are dynamically corrected according to the speed, load, intake temperature and fuel temperature of the engine.

[0089] Exemplarily, in the high speed operating condition, the X and Y components of the landing point coordinates are adjusted by considering the influence of the increased airflow speed on the oil jet trajectory; in the low temperature operating condition, the Z component of the landing point coordinates is adjusted by considering the influence of the change of the fuel viscosity on the oil jet diffusion angle. The correction makes the target landing point position adapt to the change of the engine operating condition, thereby enhancing the robustness of the system.

[0090] In an embodiment of the present application, based on step S103, a possible embodiment will be given below to non-restrictively illustrate the specific implementation thereof. S103 specifically includes the following steps: Step S1031: The sampling frequency, the range and the trigger condition are set, the physical channel mapping relationship with the pressure sensor array is established, and the synchronous acquisition of all sensor data is ensured.

[0091] Step S1032: The signal-to-noise ratio of the acquired original pressure signal is calculated and the abnormal value is detected, the invalid sensor channel is identified and marked based on the preset threshold.

[0092] In some embodiments, the signal power is calculated by the effective signal segment variance, and the noise power is estimated by the silence segment variance. The sensor health state is monitored, the continuous abnormal channel is automatically shielded, and the spatial interpolation compensation is performed by the adjacent sensor data.

[0093] Step S1033: a hybrid denoising algorithm combining wavelet transform and empirical mode decomposition is used to perform layered decomposition on the effective pressure signal, and separate the high-frequency interference component and the useful signal component.

[0094] In some embodiments, the wavelet basis function is used for decomposition, and the high-frequency coefficient is subjected to threshold processing. The intrinsic mode function is obtained by EMD decomposition, and the noise dominant IMF component is identified according to the correlation coefficient method; a weight distribution model of wavelet and EMD is established, and the useful impact pressure characteristics are retained. In this way, the time-frequency localization advantage of wavelet analysis and the adaptability of EMD are combined, the signal mutation characteristics are maintained, and various noises are effectively suppressed.

[0095] Step S1034: the signal component after denoising is reconstructed into a pressure signal according to the weight, and the zero-phase filtering is used to eliminate the signal phase distortion, and the signal baseline is dynamically compensated.

[0096] In some embodiments, the weight coefficient can be adaptively distributed according to the signal-to-noise ratio of each component; the zero-phase filtering adopts a Butterworth low-pass filter, and the cutoff frequency is dynamically adjusted according to the signal characteristics; the baseline b(t) is extracted by the moving average method combined with morphological filtering. Through the signal reconstruction and phase protection technology, the real pressure waveform is restored; through the dynamic baseline estimation, the low-frequency interference caused by the sensor temperature drift and the engine vibration is eliminated.

[0097] Step S1035: the processed pressure signals of each channel are uniformly formatted, the data sequence is reorganized according to the sensor coordinate position, and the data set for pressure field construction is generated.

[0098] In some embodiments, the accurate correspondence between the signal and the sensor position is established, the data format requirements of the subsequent spatial pressure field construction are met, and the comparability and consistency between different channel data are ensured.

[0099] In an embodiment of the present application, based on step S104, a possible embodiment will be given below to non-restrictively describe the specific implementation scheme. S104 specifically includes the following steps: Step S1041: based on the combustion chamber coordinate system, the preprocessed pressure signal is spatially mapped according to the sensor coordinates, a MxNXT three-dimensional data grid is constructed, T is the time dimension, the Delaunay triangulation algorithm is used to optimize the grid topology structure, and it is ensured that the pressure data is continuously distributed in space and has no distortion.

[0100] Step S1042: Extract the peak value, rising edge slope, pulse width, and pressure gradient, direction derivative of the pressure signal, calculate the spatio-temporal correlation degree of different sensor signals through the cross-correlation function, construct a feature correlation matrix to quantify the pressure wave propagation path.

[0101] Optionally, the peak value, rising edge slope, and pulse width of the pressure signal are extracted using wavelet packet decomposition to capture the transient components of the pressure signal. The pressure gradient and direction derivative are calculated by the Sobel operator to analyze the pressure wave propagation direction. The feature correlation matrix is processed by singular value decomposition for dimension reduction.

[0102] Step S1043: Perform three-dimensional spatial interpolation using multi-quadratic radial basis functions, optimize the interpolation stability with a regularization parameter, and interpolate the pressure values in the area without arranged sensors to reconstruct the continuous oil jet impact pressure field.

[0103] The radial basis function parameters in this embodiment are optimized by leave-one-out cross-validation to balance the interpolation accuracy and overfitting risk. The regularization parameter is determined by the generalized cross-validation criterion to ensure the stability of the interpolation.

[0104] Step S1044: Use the laser Doppler vibrometer in the engine test bench to collect the combustion chamber wall vibration signals during oil jet impact, extract the main frequency vibration mode through frequency domain analysis, and compare and calibrate with the pressure field reconstruction results to correct the interpolation model parameters to adapt to different working conditions.

[0105] Optionally, the laser vibration signal and the pressure field reconstruction result are compared through wavelet coherence analysis, and the main frequency vibration mode error is controlled within the preset error range. The calibration process uses a Kalman filter to dynamically correct the interpolation parameters to adapt to changes in working conditions.

[0106] Step S1045: Couple the reconstructed pressure field with the combustion chamber flow field and temperature field data for analysis, use the CFD-thermal coupling model to verify the correlation between the pressure field and the gas flow turbulence intensity and fuel evaporation rate, and ensure that the pressure field conforms to the physical reality.

[0107] The multi-physical field coupling analysis of this embodiment is realized using the OpenFOAM open source platform, which accelerates large-scale grid solving through parallel computing; the coupling verification is quantitatively evaluated by the energy exchange rate between the pressure field and the flow field and the temperature field.

[0108] It should be understood that the size of the serial number of each step in the above embodiments does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0109] As Figure 4As shown, the present application also provides an electronic device, comprising a display module 103, a memory 102, a processor 101, a communication module 104, and a computer program stored in the memory and executable on the processor 101, wherein the processor 101 implements the steps of the diesel oil jet drop position dynamic detection method when executing the program.

[0110] In embodiments of the present application, the electronic device includes, but is not limited to, a laptop computer, a desktop computer, a workstation, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections, and relationships, and their functions, are shown as examples only and are not meant to limit implementations of the embodiments described and / or claimed herein.

[0111] In embodiments of the present application, the processor 101 can be implemented by using at least one of an application specific integrated circuit, a programmable logic device, a field programmable gate array, a processor, a controller, a microcontroller, a microprocessor, an electronic unit designed to perform the functions described herein, and in some cases, such implementation can be implemented in a controller. For software implementation, the implementation of such as processes or functions can be implemented with separate software modules allowing at least one function or operation to be performed, and the software code can be implemented by a software application (or program) written in any suitable programming language, which can be stored in the memory and executed by the controller.

[0112] The display module 103 is used to display information input by a user or information provided to a user. The display module 103 can include a display panel, which can be configured in the form of a liquid crystal display, an organic light emitting diode, etc.

[0113] The memory 102 can be used to store software programs and various data. The memory 102 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device.

[0114] The communication module 104 transmits and / or receives radio signals to and / or from at least one of a base station, an external terminal, and a server. Such radio signals can include voice call signals, video call signals, or various types of data according to text and / or multimedia message transmission and reception.

[0115] The present application also provides a storage medium having a computer program stored thereon, wherein the computer program is executable by a processor to implement the steps of the diesel oil jet drop position dynamic detection method.

[0116] The storage medium can employ any type of a non-exhaustive list of media that can be used with computers, such as optical, magnetic, electrical, electromagnetic, infrared, or semiconductor technology, or any combination thereof. More specific examples (a non-exhaustive list) of storage media that can be employed include an electrical connection having one or more wires, a portable disc, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0117] In the storage medium, there is stored a program product capable of implementing the method described above in the specification. In some possible implementation manners, various aspects of the disclosure can also be implemented in the form of a program product, which includes program codes for causing terminal equipment to perform the steps according to various exemplary embodiments of the disclosure described in the “Exemplary Method” part of the specification when the program product runs on the terminal equipment.

[0118] The above description of disclosed embodiments enables a person skilled in the art to implement or use the invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for dynamically detecting a diesel fuel injection hit location, characterized in that, The method comprises: S101: determining an initial position at the center of the oil jet area between every two adjacent petals according to the number of petals of the combustion chamber, and determining a target oil jet landing position between every two petals according to the injection pressure and the injection hole diameter of the oil injector, the target oil jet landing position corresponding to the initial position; S102: arranging a plurality of micro pressure sensors on the inner surface of the petal-shaped combustion chamber to form a detection grid avoiding the petal protrusions; S103: collecting pressure signals of the pressure sensors and pre-processing the pressure signals by using a signal processing module to eliminate high-frequency interference signals; S104: constructing an oil jet impact pressure field in the combustion chamber according to the position coordinates of the pressure sensors and the pre-processed pressure signals, and combining the time and space distribution characteristics of the pressure signals; S105: extracting pressure field region coordinates with a pressure value not lower than a preset pressure value from the oil jet impact pressure field constructed in S104, and calculating the actual landing position of each oil jet based on the pressure field region coordinates; S106: comparing the actual oil jet landing position calculated in S105 with the target oil jet landing position determined in S102 to calculate the landing position deviation of each oil jet; S107: calculating the average value of the landing position deviations of the plurality of oil jets obtained in S106 to obtain the average oil jet deviation.

2. The method of claim 1, wherein, Step S101 further comprises the following modes: Obtaining the design parameters of the oil injector, including the injection pressure, the injection hole diameter and the injection quantity, and establishing the correspondence between the number of oil injector holes and the number of combustion chamber petals; Based on the design parameters of the oil injector, a motion trajectory model of the oil jet in the combustion chamber is constructed; According to the motion trajectory model and the geometric position of the combustion chamber petals, the expected landing point coordinates of the oil jet between every two petals are calculated; Based on the engine operating condition parameters, including the speed, load and temperature, the expected landing point coordinates are corrected.

3. The diesel oil jet landing position dynamic detection method according to claim 1, wherein S102 specifically comprises the following steps: A combustion chamber space coordinate system with the center of the piston top surface as the origin is established, and the number of initial positions is determined according to the number of combustion chamber petals; The specific coordinate values of each initial position in the space coordinate system are determined, and each initial position corresponds to the center region of an oil jet injection area; Pressure sensors are arranged at fixed intervals in the circumferential direction with each initial position as the center, and the petal protrusion area is avoided; The pressure sensors arranged in the circumferential direction are taken as the reference, and the pressure sensors are arranged at fixed intervals in the axial direction, and the arrangement range is limited by the start and end surfaces of the petals; The coordinates of all pressure sensors are recorded according to the petal area, so that the sensors in each area correspond to a specific oil jet injection area.

4. The diesel oil jet landing position dynamic detection method according to claim 1, wherein S103 specifically comprises the following steps: Set the sampling frequency, range and trigger condition, establish the physical channel mapping relationship with the pressure sensor array, and ensure that all sensor data is collected synchronously; The signal-to-noise ratio of the collected original pressure signal is calculated and the abnormal value is detected, and the invalid sensor channel is identified and marked based on the preset threshold; A hybrid denoising algorithm combining wavelet transform and empirical mode decomposition is used to hierarchically decompose the effective pressure signal, separate the high-frequency interference component from the useful signal component; The denoised signal components are reconstructed into a pressure signal according to the weight, and the signal phase distortion is eliminated through zero-phase filtering, and the signal baseline is dynamically compensated; The processed pressure signals of each channel are unified in format, and the data sequence is reorganized according to the sensor coordinate position to generate a data set.

5. The diesel oil jet landing position dynamic detection method according to claim 1, wherein S104 specifically comprises the following steps: In the combustion chamber coordinate system, the pressure signal is spatially mapped according to the sensor coordinates, a three-dimensional data grid is constructed, and the grid topology is optimized; Extracting multiple characteristic parameters of the pressure signal, calculating the correlation degree between the sensor signals, and constructing a feature correlation matrix; Using radial basis function for three-dimensional space interpolation, interpolating the pressure values in the regions where sensors are not arranged, and reconstructing the continuous pressure field; Collecting the combustion chamber wall vibration signal through the test bench, comparing it with the pressure field reconstruction result, and correcting the interpolation model parameters; Coupling analysis of the reconstructed pressure field with the airflow field and temperature field is performed to verify the physical correlation of the pressure field.

6. The diesel oil jet landing position dynamic detection method according to claim 1, wherein S105 further comprises the following steps: According to the constructed pressure field, the pressure field region coordinates where the pressure P is greater than or equal to 90% Pmax are extracted in the middle of each petal; According to the extracted pressure field region coordinates, the X-direction position Xi = ∑(Pi*Xij) / Pi, Y-direction position Yi = ∑(Pi*Yij) / Pi, and Z-direction position Zi = ∑(Pi*Zij) / Pi are calculated respectively; The actual oil jet landing position Wi corresponding to the number of oil jets is obtained.

7. The diesel oil jet landing position dynamic detection method according to claim 1, wherein S106 specifically comprises the following steps: According to the divided oil jet injection region number i = 1, 2, …, 6 ~ 8, each actual oil jet landing position Wi obtained in S105 is associated with the corresponding target oil jet landing position Ti to ensure that the same number corresponds to the landing point of the same oil jet injection region; For each associated Wi(Xi, Yi, Zi) and Ti(Xti, Yti, Zti), the X-axis direction deviation ΔXi, the Y-axis direction deviation ΔYi, and the Z-axis direction deviation ΔZi are calculated respectively, where Xi, Yi, and Zi are actual landing point coordinates, and Xti, Yti, and Zti are target landing point coordinates; The calculated ΔXi, ΔYi, and ΔZi are combined into a three-dimensional deviation vector ΔWi of the oil jet, and the oil jet number, engine operating condition parameters, and measurement time difference corresponding to the deviation vector are recorded; A reasonable range threshold Dlim for each axis deviation is preset, and for each deviation vector ΔWi, it is judged whether ΔXi, ΔYi, and ΔZi are within the range [-Dlim, Dlim], and ΔWi with all axis deviations within the reasonable range is retained as valid deviation data. Repeat the collection of 3~5 effective deviation data under the same engine operating conditions, calculate the standard deviation of each oil jet axial effective deviation, if the standard deviation ≤σlim, the deviation data of the oil jet meets the time domain stability requirements, and the deviation data is retained; otherwise, re-measure the deviation.

8. The dynamic detection method of diesel oil jet drop point position according to claim 1, characterized in that, S107 specifically comprises the following steps: Group the effective deviation data according to engine speed and load parameters to form a working condition group, and each group contains a three-dimensional deviation vector of the oil jet; For each working condition group, set the weight according to the distance between the oil jet injection area and the key components of the combustion chamber, and calculate the weighted average deviation of the three-dimensional deviation components; Extract the pressure peak coordinates of the oil jet injection area from the pressure field, calculate the deviation from the target drop point, and compare it with the weighted average deviation, and check it through the preset threshold value; Calculate the deviation spatial gradient detected by the adjacent pressure sensors around the oil jet injection area, and check it through the gradient threshold value and the deviation difference value; Trend check the average deviation under the change of speed and load to ensure that the change meets the preset interval, and generate an average deviation correlation report.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to realize the steps of the dynamic detection method of diesel oil jet drop point position according to any one of claims 1 to 8.

10. A storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to realize the steps of the dynamic detection method of diesel oil jet drop point position according to any one of claims 1 to 8.

Images