Engine intake phase deviation determination method and device, electronic equipment and storage medium

Abstract

The application relates to an engine intake phase deviation determination method and device, electronic equipment and a storage medium. The engine intake phase deviation determination method comprises the following steps: obtaining a first intake phase deviation of a reference engine; obtaining a first crank angle corresponding to the lowest cylinder pressure of the intake stroke of the reference engine; obtaining a second crank angle corresponding to the lowest cylinder pressure of the intake stroke of a measured engine; and determining a second intake phase deviation of the measured engine based on the first intake phase deviation, the first crank angle and the second crank angle. The embodiment of the application can automatically determine the second intake phase deviation of the measured engine without disassembling the engine, and the measurement result can eliminate the influence of sensor hysteresis and temperature drift characteristics on the phase deviation, and is widely applicable to rapidly and accurately measuring the intake phase physical deviation of the engine on a hybrid vehicle or a bench with a reverse drag function.

Description

Technical Field

[0001] This application relates to the field of engine testing, and in particular to a method, apparatus, electronic device and storage medium for determining engine intake phase deviation. Background Technology

[0002] Against the backdrop of the country's vigorous promotion of energy conservation and emission reduction strategies and the continuous improvement of relevant regulations and standards, variable valve timing (VVT) technology has been widely used in the field of internal combustion engines due to its significant advantage of being able to flexibly adjust the valve opening and closing time according to the specific operating conditions of the engine, so that the engine has the best valve timing under various operating conditions.

[0003] The effective application of VVT technology is of great significance for optimizing engine performance. However, the accuracy of the initial valve timing is a key prerequisite for ensuring that the engine performs well. If the initial valve timing is inaccurate, it will directly lead to insufficient air intake and poor exhaust, which in turn will affect the precise control of fuel injection and ignition. This will not only adversely affect the engine's power and economy, but also worsen emissions levels, making it difficult to meet increasingly stringent environmental protection requirements.

[0004] Of particular note is that hybrid engines employing high compression ratios are more sensitive to even minute intake phase deviations due to their inherent structure and operating characteristics. Even slight phase deviations can significantly impact the performance of these engines, severely limiting the full realization of their energy-saving and emission-reduction advantages. Therefore, ensuring the accuracy of the initial valve timing, especially effectively controlling intake phase deviations in high-compression-ratio hybrid engines, has become a crucial problem urgently needing to be solved in the field of internal combustion engine technology. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides a method, apparatus, electronic device and storage medium for determining engine intake phase deviation.

[0006] In a first aspect, this application provides a method for determining engine intake phase deviation, including:

[0007] Obtain the first intake phase deviation of the reference engine;

[0008] Obtain the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine;

[0009] Obtain the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test;

[0010] The second intake phase deviation of the engine under test is determined based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle.

[0011] Optionally, obtaining the first crankshaft angle corresponding to the minimum cylinder pressure during the intake stroke of the reference engine includes:

[0012] Obtain the first reverse cylinder pressure curve of the reference engine;

[0013] The first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine is determined based on the first inverted cylinder pressure curve.

[0014] Optionally, obtaining the first reverse cylinder pressure curve of the reference engine includes:

[0015] After starting the reference engine, perform a warm-up operation until the coolant outlet temperature of the reference engine reaches the preset temperature.

[0016] Acquire the first cylinder pressure signal from the cylinder pressure sensor and the first crankshaft position signal from the engine crank position sensor;

[0017] The first top dead center is calibrated using a combustion analyzer based on the first cylinder pressure signal and the first crankshaft position signal.

[0018] During the process of the reference engine crankshaft completing multiple working cycles, the control dragging device drags the reference engine speed back to the preset speed and keeps the throttle valve fully open, and acquires the second cylinder pressure signal from the cylinder pressure sensor and the second crankshaft position signal from the engine crank position sensor.

[0019] The first reverse cylinder pressure curve is determined using a combustion analyzer based on the first top dead center, the second cylinder pressure signal, and the second crankshaft position signal.

[0020] Optionally, determining the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine based on the first inverted cylinder pressure curve includes:

[0021] The first inverted cylinder pressure curve is subjected to elimination of cyclic fluctuations and low-frequency filtering to obtain the first intermediate cylinder pressure curve.

[0022] The first intermediate cylinder pressure curve is converted into a first pressure change rate curve.

[0023] The crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke is determined from the first pressure change rate curve and used as the first crankshaft angle.

[0024] Optionally, obtaining the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test includes:

[0025] Obtain the second reverse cylinder pressure curve of the engine under test;

[0026] The second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the tested engine is determined based on the second inverted cylinder pressure curve.

[0027] Optionally, the second inverted cylinder pressure curve of the tested engine is obtained, including:

[0028] After starting the engine under test, perform a warm-up operation until the coolant outlet temperature of the engine under test reaches the preset temperature.

[0029] Acquire the third cylinder pressure signal from the cylinder pressure sensor and the third crankshaft position signal from the engine crank position sensor;

[0030] The second top dead center is calibrated using a combustion analyzer based on the third cylinder pressure signal and the third crankshaft position signal.

[0031] During the process of the crankshaft of the engine under test completing multiple working cycles, the control drag device is used to drag the speed of the engine under test back to the preset speed and keep the throttle valve fully open, so as to obtain the fourth cylinder pressure signal from the cylinder pressure sensor and the fourth crankshaft position signal from the engine crank position sensor.

[0032] The second reverse cylinder pressure curve is determined using a combustion analyzer based on the second top dead center, the fourth cylinder pressure signal, and the fourth crankshaft position signal.

[0033] Optionally, determining the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the tested engine based on the second inverted cylinder pressure curve includes:

[0034] The second inverted cylinder pressure curve is subjected to elimination of cyclic fluctuations and low-frequency filtering to obtain the second intermediate cylinder pressure curve;

[0035] The second intermediate cylinder pressure curve is converted into a second pressure change rate curve;

[0036] The crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke is determined from the second pressure change rate curve and used as the second crankshaft angle.

[0037] Optionally, determining the second intake phase deviation of the tested engine based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle includes:

[0038] Calculate the difference between the second crankshaft angle and the first crankshaft angle to obtain the crankshaft angle deviation;

[0039] The second intake phase deviation is obtained by summing the first intake phase deviation and the crankshaft angle deviation.

[0040] Optionally, the first intake phase deviation of the reference engine is obtained, including:

[0041] The intake phase deviation of the reference engine is measured using the valve lift measurement method to obtain the first intake phase deviation.

[0042] Secondly, this application provides an engine intake phase deviation determination device, comprising:

[0043] The first acquisition module is used to acquire the first intake phase deviation of the reference engine;

[0044] The second acquisition module is used to acquire the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine;

[0045] The third acquisition module is used to acquire the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test.

[0046] The determination module is used to determine the second intake phase deviation of the engine under test based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle.

[0047] Thirdly, this application provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0048] Memory, used to store computer programs;

[0049] When the processor executes a program stored in the memory, it implements the engine intake phase deviation determination method described in any of the first aspects.

[0050] Fourthly, this application provides a computer-readable storage medium storing a program for determining an engine intake phase deviation, wherein when the program for determining an engine intake phase deviation is executed by a processor, it implements the steps of the engine intake phase deviation determination method described in any of the first aspects.

[0051] The beneficial effects of this invention are:

[0052] This embodiment of the application can automatically determine the second intake phase deviation of the engine under test by using the first intake phase deviation of the reference engine, the first crankshaft angle corresponding to the minimum cylinder pressure of the intake stroke of the reference engine, and the second crankshaft angle corresponding to the minimum cylinder pressure of the intake stroke of the engine under test. This can be done without disassembling the engine, and the measurement results can eliminate the influence of sensor hysteresis and temperature drift characteristics on the phase deviation. It is widely applicable to quickly and accurately measuring the physical deviation of the intake phase of the engine in hybrid vehicles or on a test bench with a reverse towing function. Attached Figure Description

[0053] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 A flowchart illustrating a method for determining engine intake phase deviation provided in this application embodiment;

[0056] Figure 2 for Figure 1 Flowchart of step S102;

[0057] Figure 3 for Figure 2 Flowchart of step S201;

[0058] Figure 4 for Figure 2 Flowchart of step S202;

[0059] Figure 5 for Figure 1 Flowchart of step S102;

[0060] Figure 6 for Figure 5 Flowchart of step S501;

[0061] Figure 7 for Figure 5 Flowchart of step S502;

[0062] Figure 8 A flowchart of an engine intake phase deviation determination system provided in this application embodiment;

[0063] Figure 9 A flowchart illustrating a method for determining engine intake phase deviation in a practical application, provided as an embodiment of this application;

[0064] Figure 10 This is a schematic diagram showing the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke in the cylinder pressure curve.

[0065] Figure 11 This is a structural diagram of an engine intake phase deviation determination device provided in an embodiment of this application;

[0066] Figure 12 This is a structural diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0068] Due to their high compression ratio, hybrid engines are more sensitive to even minute intake phase deviations because of their structure and operating characteristics. Even slight phase deviations can significantly impact engine performance, severely limiting the full realization of the energy-saving and emission-reduction advantages of hybrid engines. Existing sensor-based electrical signal measurement methods are simple and do not require engine disassembly, but the test results include errors caused by factors such as temperature drift and hysteresis characteristics of crankshaft and camshaft position sensors, which are not actual physical deviations in the camshaft phase. While valve lift measurement methods can eliminate errors caused by sensor factors, they require disassembling the engine cylinder head cover and installing a dedicated testing device, which is time-consuming and difficult to conduct on a complete vehicle. Therefore, this application provides a method, device, electronic device, and storage medium for determining engine intake phase deviation, to effectively control the intake phase deviation of high compression ratio hybrid engines. It can quickly and accurately measure the initial valve timing phase of the automotive engine on a complete vehicle, ensuring the accuracy of the initial valve timing phase.

[0069] This application provides a method for determining engine intake phase deviation, such as... Figure 1 As shown, it includes the following steps:

[0070] Step S101: Obtain the first intake phase deviation of the reference engine;

[0071] In this embodiment of the application, the reference engine and the engine under test are the same model. The reference engine pre-measures the intake phase deviation. The first intake phase deviation refers to the angle difference between the actual intake valve opening / closing time of the reference engine and the design theoretical value, and the unit is "degree (°)" or "°CA" (for example, the actual intake valve opening time is 5°CA earlier than the design value, that is, the phase deviation is +5°CA).

[0072] In one embodiment of this application, the intake phase deviation of a reference engine can be pre-measured using the valve lift measurement method to obtain a first intake phase deviation.

[0073] Step S102: Obtain the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine;

[0074] In this embodiment, the intake stroke is the first stroke of the reference engine's working cycle (taking a four-stroke engine as an example). When the piston moves downward, the volume inside the cylinder increases, and fresh air-fuel mixture or air is drawn in through the intake valve. The cylinder pressure changes with a characteristic of first decreasing and then increasing. The minimum cylinder pressure is the minimum cylinder pressure value when the cylinder pressure drops to the lowest point. The first crankshaft angle refers to the angle position through which the crankshaft rotates during the reference engine's intake stroke when the cylinder pressure drops to the lowest value (i.e., "minimum cylinder pressure of the intake stroke"). It is usually expressed in degrees of crankshaft angle, °CA.

[0075] In one embodiment of this application, such as Figure 2 As shown, step S102 obtains the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine, including:

[0076] Step S201: Obtain the first reverse cylinder pressure curve of the reference engine;

[0077] In one embodiment of this application, step S201 obtains the first reverse cylinder pressure curve of the reference engine, such as... Figure 3 As shown, it includes:

[0078] Step S301: After starting the reference engine, perform a warm-up operation until the coolant outlet temperature of the reference engine reaches the preset temperature.

[0079] Before performing a warm-up test on the reference engine, the reference engine can be installed on a test bench of a hybrid vehicle or an electric dynamometer with a reverse towing function. An engine speed sensor, an engine crank position sensor, and a combustion analyzer are installed on the engine cylinder head. The cylinder pressure sensor is used to detect the pressure changes in the cylinder in real time, and the engine speed sensor is used to monitor the reference engine speed in real time. The output signals of the engine speed sensor and the cylinder pressure sensor are respectively connected to the combustion analyzer.

[0080] In this embodiment, the preset temperature can be 90°C, and the engine temperature is 90°C from the hot engine to the outlet water temperature (the normal operating temperature of the engine, which varies slightly for different models). The purpose is to allow the reference engine to reach a thermally stable state, at which point the state of each component, fuel atomization, and combustion efficiency are close to the actual operating conditions, ensuring the authenticity and representativeness of the measurement data.

[0081] Step S302: Acquire the first cylinder pressure signal from the cylinder pressure sensor and the first crankshaft position signal from the engine crank position sensor;

[0082] After the reference engine is heated to a preset temperature, the first cylinder pressure signal output by the cylinder pressure sensor and the first crankshaft position signal output by the engine crank position sensor can be obtained.

[0083] Step S303: Use a combustion analyzer to calibrate the first top dead center based on the first cylinder pressure signal and the first crankshaft position signal;

[0084] The combustion analyzer receives the first crankshaft position signal from the crank position sensor, combines it with the first cylinder pressure signal, corrects the crankshaft rotation zero point, and ensures that the top dead center marked by the crank position sensor corresponds to the actual top dead center of the piston, thus obtaining the first top dead center.

[0085] Step S304: During the process of the reference engine crankshaft completing multiple working cycles, the control drag device is used to drag the reference engine speed back to the preset speed and keep the throttle valve fully open, and the second cylinder pressure signal from the cylinder pressure sensor and the second crankshaft position signal from the engine crank position sensor are obtained.

[0086] In this embodiment of the application, the number of working cycles can be 200 times, the preset speed can be 1500 r / min, and the driving device can refer to the motor in a hybrid electric vehicle or an electric dynamometer.

[0087] In this step, the reference engine crankshaft can be controlled to complete multiple working cycles. During each working cycle, the dragging device is controlled to drag the reference engine speed back to the preset speed and keep the throttle fully open to simulate a non-combustion mechanical motion state. The second cylinder pressure signal output by the cylinder pressure sensor and the second crankshaft position signal output by the engine crank position sensor are acquired in real time.

[0088] Step S305: The first reverse cylinder pressure curve is determined using a combustion analyzer based on the first top dead center, the second cylinder pressure signal, and the second crankshaft position signal.

[0089] In this step, the cylinder pressure can be obtained first from the second cylinder pressure signal, the crankshaft angle can be obtained from the second crankshaft position signal, the cylinder pressure can be plotted as a function of the crankshaft angle, and the pressure data on the curve can be associated with the first top dead center to obtain the first reverse cylinder pressure curve.

[0090] Step S202: Determine the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine based on the first inverted cylinder pressure curve.

[0091] In this step, the first inverted cylinder pressure curve can be processed by noise reduction and target extraction to obtain the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine.

[0092] In one embodiment of this application, such as Figure 4 As shown, step S202, based on the first inverted cylinder pressure curve, determines the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine, including:

[0093] Step S401: Perform cycle fluctuation elimination and low-frequency filtering on the first reverse cylinder pressure curve to obtain the first intermediate cylinder pressure curve;

[0094] In this embodiment of the application, the process of eliminating cyclic fluctuations can refer to cyclic averaging to eliminate cyclic fluctuations, and the low-frequency filtering process can filter out high-frequency noise and retain the effective pressure signal.

[0095] Step S402: Convert the first intermediate cylinder pressure curve into a first pressure change rate curve;

[0096] In this step, the first intermediate cylinder pressure curve can be differentiated to calculate the rate of change of cylinder pressure with crankshaft angle, thus obtaining the first pressure change rate curve.

[0097] Step S403: Determine the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke from the first pressure change rate curve, and use it as the first crankshaft angle.

[0098] In this step, the crankshaft angle range corresponding to the intake stroke can be filtered in the first pressure change rate curve (e.g., 180° to 360°CA after top dead center, depending on the engine model). The point where the change rate is 0 and the sign changes from negative to positive within this range is the lowest cylinder pressure point. The crankshaft angle corresponding to the lowest cylinder pressure point is obtained as the first crankshaft angle.

[0099] Step S103: Obtain the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test;

[0100] In this embodiment of the application, the second crankshaft angle refers to the angle position through which the crankshaft rotates during the intake stroke of the engine under test, when the cylinder pressure drops to the lowest value (i.e., "minimum cylinder pressure during intake stroke"). The crankshaft angle is usually expressed in degrees of crankshaft angle, °CA.

[0101] In one embodiment of this application, such as Figure 5 As shown, step S102 obtains the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test, including:

[0102] Step S501: Obtain the second reverse cylinder pressure curve of the engine under test;

[0103] In one embodiment of this application, such as Figure 6 As shown, step S501 obtains the second reverse cylinder pressure curve of the engine under test, including:

[0104] Step S601: After starting the engine under test, perform a warm-up operation until the coolant outlet temperature of the engine under test reaches the preset temperature.

[0105] Before performing a warm-up test on the engine under test, the engine can be installed on a test bench of a hybrid vehicle or an electric dynamometer with a reverse towing function. An engine speed sensor, an engine crank position sensor, and a combustion analyzer are installed on the engine cylinder head. The cylinder pressure sensor is used to detect the pressure changes in the cylinder in real time, and the engine speed sensor is used to monitor the engine speed in real time. The output signals of the engine speed sensor and the cylinder pressure sensor are respectively connected to the combustion analyzer.

[0106] In this embodiment, the preset temperature can be 90°C, and the engine temperature is 90°C from the hot engine to the outlet water temperature (the normal operating temperature of the engine, which varies slightly for different models). The purpose is to allow the engine under test to reach a thermally stable state. At this time, the state of each component, fuel atomization, and combustion efficiency are close to the actual operating conditions, ensuring the authenticity and representativeness of the measurement data.

[0107] Step S602: Acquire the third cylinder pressure signal from the cylinder pressure sensor and the third crankshaft position signal from the engine crank position sensor;

[0108] After the engine under test is heated to a preset temperature, the third cylinder pressure signal output by the cylinder pressure sensor and the third crankshaft position signal output by the engine crank position sensor can be obtained.

[0109] Step S603: Use a combustion analyzer to calibrate the second top dead center based on the third cylinder pressure signal and the third crankshaft position signal;

[0110] The combustion analyzer receives the third crankshaft position signal from the crank position sensor, combines it with the third cylinder pressure signal, corrects the crankshaft rotation zero point, and ensures that the top dead center marked by the crank position sensor corresponds to the actual top dead center of the piston, thus obtaining the second top dead center.

[0111] Step S604: During the process of the crankshaft of the engine under test completing multiple working cycles, the control drag device is used to drag the speed of the engine under test back to the preset speed and keep the throttle valve fully open, and the fourth cylinder pressure signal from the cylinder pressure sensor and the fourth crankshaft position signal from the engine crank position sensor are obtained.

[0112] In this embodiment of the application, the number of working cycles can be 200 times, the preset speed can be 1500 r / min, and the driving device can refer to the motor in a hybrid electric vehicle or an electric dynamometer.

[0113] In this step, the crankshaft of the engine under test can be controlled to complete multiple working cycles. During each working cycle, the dragging device is controlled to drag the speed of the engine under test back to the preset speed and keep the throttle fully open to simulate a non-combustion mechanical motion state. The fourth cylinder pressure signal output by the cylinder pressure sensor and the fourth crankshaft position signal output by the engine crank position sensor are acquired in real time.

[0114] Step S605: The second reverse cylinder pressure curve is determined using a combustion analyzer based on the second top dead center, the fourth cylinder pressure signal, and the fourth crankshaft position signal.

[0115] In this step, the cylinder pressure can be obtained first from the fourth cylinder pressure signal, the crankshaft angle can be obtained from the fourth crankshaft position signal, the cylinder pressure can be plotted as a function of the crankshaft angle, and the pressure data on the curve can be associated with the second top dead center to obtain the second reverse cylinder pressure curve.

[0116] Step S502: Determine the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test based on the second inverted cylinder pressure curve.

[0117] In this step, the second inverted cylinder pressure curve can be processed by noise reduction and target extraction to obtain the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine.

[0118] In one embodiment of this application, such as Figure 7 As shown, step S502, based on the second inverted cylinder pressure curve, determines the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the tested engine, including:

[0119] Step S701: Perform cycle fluctuation elimination and low-frequency filtering on the second reverse cylinder pressure curve to obtain the second intermediate cylinder pressure curve;

[0120] In this embodiment of the application, the process of eliminating cyclic fluctuations can refer to cyclic averaging to eliminate cyclic fluctuations, and the low-frequency filtering process can filter out high-frequency noise and retain the effective pressure signal.

[0121] Step S702: Convert the second intermediate cylinder pressure curve into a second pressure change rate curve;

[0122] In this step, the derivative of the second intermediate cylinder pressure curve can be calculated to determine the rate of change of cylinder pressure with crankshaft angle, thus obtaining the second pressure change rate curve.

[0123] Step S703: Determine the crankshaft angle corresponding to the lowest cylinder pressure of the intake stroke in the second pressure change rate curve, and use it as the second crankshaft angle.

[0124] In this step, the crankshaft angle range corresponding to the intake stroke can be filtered in the second pressure change rate curve (e.g., 180° to 360°CA after top dead center, depending on the engine model). The point where the change rate is 0 and the sign changes from negative to positive within this range is the lowest cylinder pressure point. The crankshaft angle corresponding to the lowest cylinder pressure point is obtained as the second crankshaft angle.

[0125] Step S104: Determine the second intake phase deviation of the engine under test based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle.

[0126] In this step, the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle can be substituted into the preset engine intake phase deviation calculation formula to obtain the second intake phase deviation of the engine under test.

[0127] The formula for calculating engine intake phase deviation is as follows:

[0128] α2=α1+β2-β1

[0129] Where α2 is the second intake phase deviation, α1 is the first intake phase deviation, β2 is the second crankshaft angle, and β1 is the first crankshaft angle.

[0130] In one embodiment of this application, step S104, which determines the second intake phase deviation of the engine under test based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle, includes:

[0131] Calculate the difference between the second crankshaft angle and the first crankshaft angle to obtain the crankshaft angle deviation; calculate the sum of the first intake phase deviation and the crankshaft angle deviation to obtain the second intake phase deviation.

[0132] This application embodiment can automatically determine the second intake phase deviation of the tested engine by using the first intake phase deviation of the reference engine, the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine, and the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the tested engine. This eliminates the need to disassemble the engine, and the measurement results can eliminate the influence of sensor hysteresis and temperature drift characteristics on the phase deviation. It is widely applicable to the rapid and accurate measurement of the physical deviation of the engine's intake phase in hybrid vehicles or on test benches with a drag-down function. The drag-down cylinder pressure method provided in this application embodiment can be used in conjunction with the valve lift measurement method for intake phase deviation control during engine research and development and production, as well as for troubleshooting engine performance issues in vehicles.

[0133] For ease of understanding, this application provides an embodiment in a practical application, such as... Figure 8As shown, the engine intake phase deviation determination system includes: a hybrid vehicle / electric dynamometer, an engine, a cylinder pressure sensor, an engine crankshaft position sensor, a combustion analyzer, a cylinder pressure curve data processing module, etc. Figure 9 As shown, the method for determining the engine intake phase deviation is as follows:

[0134] Step 1: Select a benchmark engine of the same model whose phase deviation has been measured using the valve lift measurement method. Record the physical deviation of its intake phase as α1. Then, install the cylinder pressure sensor and combustion analyzer, and connect the engine crankshaft position sensor signal to the combustion analyzer. After warming the engine to a coolant temperature of 90°C, use the signals from the cylinder pressure sensor and engine crankshaft position sensor for top dead center calibration. Next, control the hybrid vehicle / electric dynamometer to reverse the engine to 1500 rpm while keeping the throttle fully open, and record the cylinder pressure curve for 200 cycles using the combustion analyzer. Finally, use the data processing module to perform cyclic averaging, low-pass filtering, differentiation, and minimum value finding operations on the original cylinder pressure curve to obtain the crankshaft angle β1 corresponding to the lowest cylinder pressure during the intake stroke of the benchmark engine. Figure 10 As shown.

[0135] If the reference engine already has valve lift phase deviation and cylinder pressure data, subsequent measurements of intake phase physical deviation for the same engine model can be directly retrieved from the database, and this step can be omitted.

[0136] Step 2: Install the cylinder pressure sensor and combustion analyzer on the hybrid vehicle, and connect the engine crankshaft position sensor signal to the combustion analyzer. After warming up the engine to an outlet water temperature of 90°C, calibrate the top dead center using the cylinder pressure sensor and engine crankshaft position sensor signals. Then, control the hybrid vehicle / electric dynamometer to reverse the engine to 1500 r / min while keeping the throttle fully open. Record the cylinder pressure curve for 200 cycles using the combustion analyzer. Use the data processing module to perform cyclic averaging, low-pass filtering, differentiation, and minimum value finding on the original cylinder pressure curve to obtain the crankshaft angle β2 corresponding to the lowest cylinder pressure during the intake stroke of the tested engine. Figure 10 As shown.

[0137] Step 3: Since this scheme uses the engine crankshaft position sensor signal for top dead center calibration, the crankshaft angles (β1 and β2) corresponding to the lowest cylinder pressure during the engine intake stroke include the actual crankshaft angle (β1). 01 and β 02 The errors caused by the engine curvature sensor (δcurvature1 and δcurvature2) are denoted by the following formulas:

[0138] β1=β 01 +δ 曲位 1 (1)

[0139] β2=β02 +δ 曲位 twenty two)

[0140] Where β1 is the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine, and β2 is the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine. 01 β is the actual crankshaft angle of the reference engine. 02 δ represents the actual crankshaft rotation angle of the engine under test. 曲位 1 represents the error of the reference engine crank position sensor, δ 曲位 2 represents the error of the reference engine crank position sensor.

[0141] Since both the reference engine and the engine under test are calibrated at top dead center after the engine is warmed up, the errors caused by temperature drift and hysteresis of the engine crankshaft position sensor can be considered equal, that is:

[0142] δ 曲位 1 = δ 曲位 twenty three)

[0143] Where, δ 曲位 1 represents the error of the reference engine crank position sensor, δ 曲位 2 represents the error of the reference engine crank position sensor.

[0144] Finally, as Figure 4 As shown, based on the synchronous change law of the crankshaft angle corresponding to the minimum cylinder pressure during the intake stroke and the inverted cylinder pressure curve, we can obtain:

[0145] α2-α1=β 02 –β 01 (4)

[0146] Where α1 is the physical deviation of the intake phase of the reference engine, α2 is the physical deviation of the intake phase of the tested engine, and β 02 β represents the actual crankshaft rotation angle of the engine under test. 01 This is the actual crankshaft angle of the benchmark engine.

[0147] Substituting formulas (1), (2), and (3) into (4), we finally obtain the physical deviation of the intake phase of the tested engine:

[0148] α2=α1+β2-β1 (5)

[0149] Where α1 is the physical deviation of the intake phase of the reference engine, α2 is the physical deviation of the intake phase of the tested engine, β1 is the crankshaft angle corresponding to the minimum cylinder pressure of the intake stroke of the reference engine, and β2 is the crankshaft angle corresponding to the minimum cylinder pressure of the intake stroke of the reference engine.

[0150] Taking the measurement of the physical deviation of the intake phase of a hybrid vehicle engine as an example:

[0151] First, select any engine of the same type that has already undergone phase deviation testing using the valve lift measurement method as the reference engine. It is known that its intake phase lag is 5°CA, denoted as +5°CA. Install the engine on a hybrid vehicle or a test bench with a reverse-draft function. Measure its reverse-draft cylinder pressure curve according to step 1, and through data processing, obtain the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine as -320°CA. If the database already contains valve lift and cylinder pressure curve data for the reference engine, this step can be skipped.

[0152] Then, the inverted cylinder pressure curve of the engine under test was measured on the hybrid vehicle according to step 2, and the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test was obtained as -318°CA through data processing.

[0153] Finally, according to formula (5) in step 3, the physical deviation of the intake phase of the tested engine is obtained as 5-318+320=7°CA, that is, the intake phase of the tested engine is lagging by 7°CA.

[0154] In another embodiment of this application, an engine intake phase deviation determination device is also provided, such as... Figure 11 As shown, it includes:

[0155] The first acquisition module 11 is used to acquire the first intake phase deviation of the reference engine;

[0156] The second acquisition module 12 is used to acquire the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine;

[0157] The third acquisition module 13 is used to acquire the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test.

[0158] The determination module 14 is used to determine the second intake phase deviation of the engine under test based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle.

[0159] In another embodiment of this application, an electronic device is also provided, characterized in that it includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0160] Memory, used to store computer programs;

[0161] When the processor executes the program stored in the memory, it implements the engine intake phase deviation determination method described in any of the foregoing method embodiments.

[0162] The electronic device provided in this invention, through its processor executing a program stored in its memory, can automatically determine the second intake phase deviation of the engine under test based on the first intake phase deviation of the reference engine, the first crankshaft angle corresponding to the minimum cylinder pressure of the intake stroke of the reference engine, and the second crankshaft angle corresponding to the minimum cylinder pressure of the intake stroke of the engine under test. This can be achieved without disassembling the engine, and the measurement results can eliminate the influence of sensor hysteresis and temperature drift characteristics on the phase deviation. It is widely applicable to the rapid and accurate measurement of the physical deviation of the intake phase of engines in hybrid vehicles or on test benches with a reverse towing function.

[0163] The communication bus 1140 mentioned in the above-mentioned electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus 1140 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 12 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0164] The communication interface 1120 is used for communication between the above-mentioned electronic device and other devices.

[0165] The memory 1130 may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0166] The processor 1110 mentioned above can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0167] In another embodiment of this application, a computer-readable storage medium is also provided, characterized in that the computer-readable storage medium stores a program for determining an engine intake phase deviation, wherein when the program for determining an engine intake phase deviation is executed by a processor, it implements the steps of the engine intake phase deviation determination method described in any of the foregoing method embodiments.

[0168] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0169] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for determining engine intake phase deviation, characterized in that, include: Obtain the first intake phase deviation of the reference engine; Obtain the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine; Obtain the first crankshaft angle corresponding to the minimum cylinder pressure during the intake stroke of the reference engine, including: Obtaining the first reverse cylinder pressure curve of the reference engine includes: starting the reference engine and performing warm-up operation until the coolant outlet temperature of the reference engine reaches a preset temperature; obtaining a first cylinder pressure signal from a cylinder pressure sensor and a first crankshaft position signal from an engine crank position sensor; calibrating the first top dead center using a combustion analyzer based on the first cylinder pressure signal and the first crankshaft position signal; during multiple working cycles of the reference engine's crankshaft, controlling a dragging device to reverse the reference engine's speed to a preset speed while maintaining the throttle fully open, and obtaining a second cylinder pressure signal from the cylinder pressure sensor and a first top dead center signal from the engine crank position sensor. The process involves: using a combustion analyzer to determine the first backward-dragging cylinder pressure curve based on the first top dead center, the second cylinder pressure signal, and the second crankshaft position signal; determining the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine based on the first backward-dragging cylinder pressure curve; and determining the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine based on the first backward-dragging cylinder pressure curve, including: performing cycle fluctuation elimination and low-frequency filtering on the first backward-dragging cylinder pressure curve to obtain a first intermediate cylinder pressure curve; converting the first intermediate cylinder pressure curve into a first pressure change rate curve; and determining the crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke from the first pressure change rate curve, as the first crankshaft angle. Obtain the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test; The second intake phase deviation of the engine under test is determined based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle. Determining the second intake phase deviation of the tested engine based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle includes: Calculate the difference between the second crankshaft angle and the first crankshaft angle to obtain the crankshaft angle deviation; The second intake phase deviation is obtained by summing the first intake phase deviation and the crankshaft angle deviation.

2. The method for determining engine intake phase deviation according to claim 1, characterized in that, Obtaining the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test includes: Obtain the second reverse cylinder pressure curve of the engine under test; The second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the tested engine is determined based on the second inverted cylinder pressure curve.

3. The method for determining engine intake phase deviation according to claim 1, characterized in that, Obtaining the second inverted cylinder pressure curve of the tested engine includes: After starting the engine under test, perform a warm-up operation until the coolant outlet temperature of the engine under test reaches the preset temperature. Acquire the third cylinder pressure signal from the cylinder pressure sensor and the third crankshaft position signal from the engine crank position sensor; The second top dead center is calibrated using a combustion analyzer based on the third cylinder pressure signal and the third crankshaft position signal. During the process of the crankshaft of the engine under test completing multiple working cycles, the control drag device is used to drag the speed of the engine under test back to the preset speed and keep the throttle valve fully open, so as to obtain the fourth cylinder pressure signal from the cylinder pressure sensor and the fourth crankshaft position signal from the engine crank position sensor. The second reverse cylinder pressure curve is determined using a combustion analyzer based on the second top dead center, the fourth cylinder pressure signal, and the fourth crankshaft position signal.

4. The method for determining engine intake phase deviation according to claim 1, characterized in that, Determining the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the tested engine based on the second inverted cylinder pressure curve includes: The second inverted cylinder pressure curve is subjected to elimination of cyclic fluctuations and low-frequency filtering to obtain the second intermediate cylinder pressure curve; The second intermediate cylinder pressure curve is converted into a second pressure change rate curve; The crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke is determined from the second pressure change rate curve and used as the second crankshaft angle.

5. The method for determining engine intake phase deviation according to claim 1, characterized in that, Obtain the first intake phase deviation of the reference engine, including: The intake phase deviation of the reference engine is measured using the valve lift measurement method to obtain the first intake phase deviation.

6. An engine intake phase deviation determination device, used to implement the engine intake phase deviation determination method of claims 1-5, characterized in that, include: The first acquisition module is used to acquire the first intake phase deviation of the reference engine; The second acquisition module is used to acquire the first crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the reference engine; The third acquisition module is used to acquire the second crankshaft angle corresponding to the lowest cylinder pressure during the intake stroke of the engine under test. The determination module is used to determine the second intake phase deviation of the engine under test based on the first intake phase deviation, the first crankshaft angle, and the second crankshaft angle.

7. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor, when executing a program stored in the memory, implements the engine intake phase deviation determination method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program for determining an engine intake phase deviation, which, when executed by a processor, implements the steps of the engine intake phase deviation determination method according to any one of claims 1-5.

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