A method and system for extracting torsional vibration excitation loads of a power transmission system

Abstract

The present invention discloses a method and system for extracting torsional vibration excitation loads of a power transmission system. Under the actual operating conditions of the vehicle, torsional vibration tests are carried out on the flywheel end of the engine to obtain the torsional vibration signals output by the engine. The rotational speed fluctuation data is processed to obtain the filtered angular acceleration fluctuation signal output by the engine. Then, according to the structure of the rotating components of the vehicle engine, the total moment of inertia of the rotating components is measured. Through the vector operation of the filtered angular acceleration fluctuation signal and the total moment of inertia, the torsional vibration excitation loads are extracted. The extraction process method is simple, simplifies the excitation load extraction process, improves the efficiency of excitation load extraction, and can load the calculated torsional vibration excitation loads into the lumped parameter torsional vibration forced response simulation analysis model. Through the comparative analysis of the simulation and test results of the torsional vibration order slices at the flywheel end of the engine and the input end of the rear axle, the torsional vibration simulation results have high accuracy and meet the accuracy requirements of torsional vibration lumped parameter simulation analysis.

Description

Technical Field

[0001] The present invention relates to the field of vibration test control of vehicle drive systems, and particularly to a method and system for extracting torsional vibration excitation loads of a power drive system. Background Art

[0002] The torsional vibration of a vehicle power drive system is mainly transmitted to the interior of the vehicle through the intermediate support of the drive shaft, the rear axle, and the rear suspension structure, causing vibration and noise problems such as resonance of the seat and steering wheel, booming inside the vehicle, gear howling, and knocking. For a general power drive system, its torsional vibration frequency is mainly distributed in the low-frequency range within 100 Hz. For the torsional vibration problem of the power drive system in this frequency band, the lumped parameter method is commonly used for simulation analysis research. By establishing a torsional vibration lumped parameter simulation analysis model, simulation analyses such as torsional vibration mode, torsional vibration forced response, and torsional vibration sensitivity are carried out, and then potential torsional vibration risks are discovered to solve the torsional vibration problem.

[0003] When performing simulation analysis of the torsional vibration forced response and torsional vibration sensitivity of a power drive system, the difficulty lies in the extraction of the torsional vibration excitation load of the power drive system. Usually, the output torque of the engine is used as the torsional vibration excitation load of the power drive system, and an engine output torque excitation model is established. The calculation of the gas pressure torque of each cylinder of the engine requires the test value of the in-cylinder gas pressure of each cylinder of the engine as input. The commonly used in-cylinder pressure test of each cylinder of the engine is the in-cylinder pressure test of each cylinder on the engine test bench. However, the in-cylinder pressure of each cylinder based on the engine test bench state test cannot reflect the in-cylinder pressure of each cylinder of the engine under the actual operating conditions of the vehicle, that is, it causes errors in the calculation of the engine output gas torque. At the same time, only considering the engine output torque excitation load as the torsional vibration excitation of the power drive system ignores the influence of the additional torque excitation of the non-constant velocity universal joint of the power drive system on the torsional vibration of the power drive system; as well as the influence of the transmission system clearance and the change of the vehicle load on the torsional vibration of the power drive system.

[0004] Accurately extracting the torsional vibration excitation load of the power drive system is of great significance for improving the accuracy of the torsional vibration simulation analysis results, and can provide an optimization guide for solving the torsional vibration problem of the power drive system. However, in the currently adopted method of extracting the engine output torque excitation load as the torsional vibration excitation load of the power drive system through in-cylinder pressure test bench test and programming calculation of the engine, it involves complex programming calculation of the engine output torque excitation model, and the extracted torsional vibration excitation cannot cover various factors that affect the torsional vibration of the power drive system, which has limitations, resulting in errors in the calculation of the engine output gas torque and affecting the accuracy of the transmission system torsional vibration simulation analysis results. Summary of the Invention

[0005] The present invention provides a method and system for extracting torsional vibration excitation load of a power transmission system, which comprehensively considers various factors affecting the torsional vibration of the power transmission system, simplifies the excitation load extraction process, and improves the extraction efficiency.

[0006] To solve the above technical problems, an embodiment of the present invention provides a method for extracting torsional vibration excitation load of a power transmission system, including:

[0007] Performing torsional vibration test on the flywheel end of the engine under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine;

[0008] Processing the rotational speed fluctuation data of the torsional vibration signal to obtain the filtered angular acceleration fluctuation signal output by the engine;

[0009] According to the structure of the engine operating components of the whole vehicle, measuring the total rotational inertia of the engine operating components, where the engine operating components include belt pulleys, timing sprockets, crankshafts, piston connecting rod groups, flywheels, and clutch housings;

[0010] Obtaining the torsional vibration excitation load of the power transmission system through vector operation of the filtered angular acceleration fluctuation signal output by the engine and the total rotational inertia of the engine operating components.

[0011] Implementing the embodiment of the present invention, by performing torsional vibration test under actual operating conditions, various actual factors affecting the torsional vibration of the power transmission system are comprehensively considered, such as engine output torque excitation, additional torque excitation of the non-uniform velocity universal joint of the drive shaft, clearance of the transmission system, and fluctuation of the vehicle load. Based on this, the total rotational inertia of the engine operating components is calculated, and then the torsional vibration excitation load of the power transmission system is obtained through vector operation of the filtered angular acceleration fluctuation signal and the total rotational inertia of the engine operating components. In the whole process of extracting the torsional vibration excitation load, only rotational speed fluctuation data processing and vector operation are involved, and it is not necessary to establish a complex engine output torque excitation model. The method is simple, simplifies the excitation extraction process, has strong applicability and reliability, and can also be applied to the analysis of torsional vibration problems of electric vehicles.

[0012] As a preferred solution, the processing of the rotational speed fluctuation data of the torsional vibration signal to obtain the filtered angular acceleration fluctuation signal output by the engine is specifically:

[0013] Extracting the rotational speed signal of the engine at one pulse from the torsional vibration signal according to a preset rotational speed conversion function;

[0014] Subtracting the rotational speed signal from the torsional vibration signal to obtain a rotational speed fluctuation signal;

[0015] Differentiating the rotational speed fluctuation signal to obtain an angular acceleration fluctuation signal;

[0016] Perform high-pass filtering on the angular acceleration fluctuation signal to obtain the filtered angular acceleration fluctuation signal output by the engine.

[0017] Implementing the embodiments of the present invention, in order to accurately extract torsional vibration, it is required to accurately measure the fluctuating part of the rotational speed during measurement. Through the signal preprocessing process of subtracting the rotational speed signal from the torsional vibration signal, the fluctuating part of the rotational speed is extracted, and the variation curve of the fluctuating rotational speed with time is obtained. Then, by performing high-pass filtering on the differentiated angular acceleration fluctuation signal, the baseline fluctuation influence of the low-frequency components caused by differentiation is filtered out, and the signal of the fluctuating part of the rotational speed that causes torsional vibration problems is accurately obtained.

[0018] As a preferred solution, the torsional vibration test is carried out on the flywheel end of the engine under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine. Specifically:

[0019] According to the preset engine speed range and the corresponding transmission gear in the actual operating conditions, the torsional vibration test is carried out on the flywheel end of the engine for the torsional vibration test under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine;

[0020] Among them, the preset engine speed range is selected to cover the speed range where torsional vibration problems occur in the whole vehicle under the actual operating conditions, and the transmission gear of the corresponding speed range under the actual operating conditions is selected to carry out the torsional vibration test;

[0021] The actual operating conditions of the whole vehicle include the slow acceleration driving condition, the rapid acceleration driving condition, and the deceleration driving condition.

[0022] Implementing the embodiments of the present invention, the torsional vibration test is carried out under the actual operating conditions, comprehensively considering the actual torsional vibration problems of the whole vehicle. At the same time, during the test process, the engine speed range covers the speed range where torsional vibration problems occur in the whole vehicle under the actual operating conditions, and the corresponding transmission gear is selected to obtain the most reliable torsional vibration signal closest to the real situation, which is used as the basis for subsequent data signal processing to reduce the error of extracting the excitation load from the source.

[0023] As a preferred solution, the obtaining of the torsional vibration signal output by the engine is specifically:

[0024] An electromagnetic torsional vibration sensor is set on the flywheel housing of the engine, and the torsional vibration electrical signal at the flywheel end of the engine is collected through the electromagnetic torsional vibration sensor, and the torsional vibration electrical signal at the flywheel end of the engine is subjected to analog-to-digital conversion to obtain the torsional vibration signal output by the engine;

[0025] Among them, the center point of the front end face of the electromagnetic torsional vibration sensor is directly opposite to the tooth surface of the flywheel teeth of the engine, and the distance between the center point of the end face and the measured tooth surface is 1-2 mm.

[0026] In the implementation of the embodiments of the present invention, an electromagnetic torsional vibration sensor is selected for testing at the flywheel end of the engine. The electromagnetic torsional vibration sensor has a large linear working range and high sensitivity. The center point of the front end face of the electromagnetic torsional vibration sensor is directly opposite to the tooth surface of the flywheel teeth of the engine, and the distance between the two is controlled within 1 - 2 mm. This position is the best installation position within the linear working section of the sensor. By measuring the torsional vibration change in a non-contact manner, the accuracy of the obtained torsional vibration signal is high, ensuring the accuracy of the torsional vibration test and obtaining an accurate torsional vibration signal.

[0027] As a preferred solution, under the actual operating conditions of the whole vehicle, torsional vibration testing is carried out on the flywheel end of the engine to obtain the torsional vibration signal output by the engine. Specifically:

[0028] By loading a simple multi-rigid body model of engine multi-body dynamics, corresponding geometric parameters and inertial parameters of the crank connecting rod mechanism are input under the actual operating conditions of the whole vehicle, and the in-cylinder pressure test data of each cylinder is loaded in the multi-body dynamics simple multi-rigid body model. The torsional vibration signal output by the engine crankshaft is extracted through simulation calculation.

[0029] In the implementation of the embodiments of the present invention, through the simple multi-rigid body simulation modeling of engine multi-body dynamics, the adaptability is stronger and the efficiency is higher, and it is applicable to different power transmission systems and different vehicle models (electric vehicles, fuel vehicles) including different engines, different transmissions, etc.

[0030] As a preferred solution, according to the structure of the engine rotating components of the whole vehicle, the total moment of inertia of the engine rotating components is measured. The engine rotating components include belt pulleys, timing sprockets, crankshafts, piston connecting rod groups, flywheels, and clutch housings. Specifically:

[0031] Measure and calculate the moment of inertia values of the belt pulley, timing sprocket, crankshaft, piston connecting rod group, flywheel, and clutch housing, and after accumulating the moment of inertia values of the engine rotating components, obtain the total moment of inertia of the engine rotating components;

[0032] Among them, the moment of inertia value of the piston connecting rod group is measured and calculated by the equivalent energy method, and the moment of inertia values of the remaining rotating components are directly measured through digital models.

[0033] In the implementation of the embodiments of the present invention, by calculating with corresponding methods for different engine rotating components, the moment of inertia values of the engine rotating components are accurately obtained, comprehensively considering various factors affecting the torsional vibration of the power transmission system due to the moment of inertia of various rotating components, and improving the accuracy and reliability of the torsional vibration excitation load extracted by this method.

[0034] As a preferred solution, through the vector operation of the angular acceleration fluctuation filtering signal output by the engine and the total moment of inertia of the engine rotating components, the torsional vibration excitation load of the power transmission system is obtained. Specifically:

[0035] The torsional vibration excitation load T of the power transmission system is calculated according to the following formula t :

[0036]

[0037] where J e is the total moment of inertia of the rotating components of the engine, and is the filtered signal of the angular acceleration fluctuation output by the engine.

[0038] Implementing the embodiments of the present invention, the torsional vibration excitation load is extracted by the dot product of the total moment of inertia of the rotating components of the engine and the filtered signal of the angular acceleration fluctuation output by the engine, and the operation is simple.

[0039] To solve the same technical problem, the embodiments of the present invention also provide a system for extracting the torsional vibration excitation load of a power transmission system, including: a torsional vibration signal acquisition module, a torsional vibration signal data processing module, a rotating component moment of inertia measurement module, and a torsional vibration excitation load extraction module;

[0040] wherein, the torsional vibration signal acquisition module is used to perform a torsional vibration test on the flywheel end of the engine under the actual operating conditions of the vehicle to obtain the torsional vibration signal output by the engine;

[0041] The torsional vibration signal data processing module is used to process the torsional vibration signal for rotational speed fluctuation data to obtain the filtered signal of the angular acceleration fluctuation output by the engine;

[0042] The rotating component moment of inertia measurement module is used to measure the total moment of inertia of the rotating components of the engine according to the structure of the rotating components of the vehicle engine, and the rotating components of the engine include a belt pulley, a timing sprocket, a crankshaft, a piston connecting rod group, a flywheel, and a clutch housing;

[0043] The torsional vibration excitation load extraction module is used to obtain the torsional vibration excitation load of the power transmission system through the vector operation of the filtered signal of the angular acceleration fluctuation output by the engine and the total moment of inertia of the rotating components of the engine.

[0044] As a preferred solution, the torsional vibration signal acquisition module includes: a sensor setting unit and an actual condition torsional vibration test unit;

[0045] Among them, the sensor setting unit is used to set an electromagnetic torsional vibration sensor on the engine flywheel housing, collect the torsional vibration electrical signal at the engine flywheel end through the electromagnetic torsional vibration sensor, perform analog-to-digital conversion on the torsional vibration electrical signal at the engine flywheel end, and obtain the torsional vibration signal output by the engine; the torsional vibration test unit under actual working conditions is used to perform a torsional vibration test on the engine flywheel end according to the preset engine speed range and the corresponding transmission gear in the actual operating conditions, and obtain the torsional vibration signal output by the engine.

[0046] The torsional vibration signal data processing module includes: a speed extraction unit, a speed fluctuation calculation unit, a differential calculation unit, and a filtering unit.

[0047] Among them, the speed extraction unit is used to extract the engine speed signal at one pulse from the torsional vibration signal according to a preset speed conversion function; the speed fluctuation calculation unit is used to subtract the speed signal from the torsional vibration signal to obtain a speed fluctuation signal; the differential calculation unit is used to perform differentiation on the speed fluctuation signal to obtain an angular acceleration fluctuation signal; the filtering unit is used to perform high-pass filtering on the angular acceleration fluctuation signal to obtain the filtered angular acceleration fluctuation signal output by the engine.

[0048] As a preferred solution, the rotating inertia measurement module of the rotating component is specifically:

[0049] Measure and calculate the rotating inertia values of the belt pulley, timing sprocket, crankshaft, piston connecting rod group, flywheel, and clutch housing, and after accumulating the rotating inertia values of the engine rotating components, obtain the total rotating inertia value of the engine rotating components; among them, the rotating inertia value of the piston connecting rod group is measured and calculated by the equivalent energy method, and the rotating inertia values of the remaining rotating components are directly measured by digital models.

[0050] The torsional vibration excitation load extraction module is specifically:

[0051] Calculate and obtain the torsional vibration excitation load T of the power transmission system according to the following formula t :

[0052]

[0053] Among them, J e is the total rotating inertia value of the engine rotating components, is the filtered angular acceleration fluctuation signal output by the engine. Description of the Drawings

[0054] Figure 1 : It is a schematic diagram of the torsional vibration excitation load extraction process of a method for extracting the torsional vibration excitation load of a power transmission system provided by the present invention;

[0055] Figure 2 : Schematic diagram of the torsional vibration excitation load simulation verification process for a torsional vibration excitation load extraction method provided by the present invention;

[0056] Figure 3 : Torsional vibration excitation load diagram of a torsional vibration excitation load extraction method and system provided by the present invention;

[0057] Figure 4 : Time-domain curve diagram of the rotational speed fluctuation at the engine flywheel end and the input end of the rear axle for a torsional vibration excitation load extraction method provided by the present invention;

[0058] Figure 5 : Comparison diagram of the simulation test of the torsional vibration engine ignition order slice of the rotational speed fluctuation at the engine flywheel end for a torsional vibration excitation load extraction method provided by the present invention;

[0059] Figure 6 : Comparison diagram of the simulation test of the torsional vibration engine ignition order slice of the rotational speed fluctuation at the input end of the rear axle for a torsional vibration excitation load extraction method provided by the present invention;

[0060] Figure 7 : Schematic structural diagram of a torsional vibration excitation load extraction system provided by the present invention. Specific embodiments

[0061] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0062] Embodiment 1

[0063] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the process of an embodiment of the torsional vibration excitation load extraction method for the power transmission system provided by the present invention, including steps 101 to 104. To further verify the accuracy of the extracted torsional vibration excitation load, refer to Figure 2 , and perform simulation loading verification on the extracted torsional vibration excitation load. Figure 2 which is a schematic diagram of the torsional vibration excitation load simulation verification process for a torsional vibration excitation load extraction method and system provided by the present invention, including steps 201 to 204. The specific steps are as follows:

[0064] Step 101: Conduct torsional vibration testing on the flywheel end of the engine under the actual operating conditions of the vehicle to obtain the torsional vibration signal output by the engine.

[0065] In this embodiment, an electromagnetic torsional vibration sensor is arranged on the engine flywheel housing. The torsional vibration electrical signal at the flywheel end of the engine is collected through the electromagnetic torsional vibration sensor, and the torsional vibration electrical signal at the flywheel end of the engine is subjected to analog-to-digital conversion to obtain the torsional vibration signal output by the engine. The center point of the front end face of the electromagnetic torsional vibration sensor is directly opposite to the tooth surface of the engine flywheel teeth, and the distance between the center point of the end face and the measured tooth surface is 1-2 mm.

[0066] According to the preset engine speed range and the corresponding transmission gear in the actual operating conditions, conduct torsional vibration testing on the flywheel end of the engine during torsional vibration testing under the actual operating conditions of the vehicle to obtain the torsional vibration signal output by the engine; the vehicle torsional vibration test conditions are selected comprehensively according to the torsional vibration problems of the actual vehicle. The actual operating conditions of the vehicle include slow acceleration driving conditions, rapid acceleration driving conditions, and deceleration driving conditions.

[0067] Among them, the preset engine speed range is selected to cover the speed range where torsional vibration problems occur in the vehicle under the actual operating conditions, and the transmission gear in the corresponding speed range under the actual operating conditions is selected to conduct the torsional vibration testing; in the torsional vibration testing in this embodiment, the engine speed range needs to cover the speed range where torsional vibration problems occur in the actual vehicle, and the corresponding transmission gear is selected. To ensure the effectiveness of the torsional vibration test results, the number of pulses per revolution of the torsional vibration test is adjusted accordingly according to the torsional vibration frequency band obtained from the actual power transmission system. In the frequency range where the torsional vibration frequency is within 100 HZ, the number of pulses per revolution should be no less than 60.

[0068] As an example of this embodiment, it is also possible to input the corresponding crankshaft connecting rod mechanism geometric parameters and inertia parameters under the actual operating conditions of the vehicle by loading a simple multi-rigid body model of engine multi-body dynamics, load the in-cylinder pressure test data of each cylinder in the simple multi-rigid body model of multi-body dynamics, and extract the torsional vibration signal output by the engine crankshaft through simulation calculation.

[0069] Step 102: Process the torsional vibration signal for rotational speed fluctuation data to obtain the angular acceleration fluctuation filtering signal output by the engine.

[0070] In this embodiment, the processing of the rotational speed fluctuation data of the torsional vibration signal has the following steps:

[0071] Step S1: Extract the engine speed signal at one pulse from the torsional vibration signal according to the preset speed conversion function (TACHO_MOMENTS_TO_RPM function);

[0072] Step S2: Subtract the speed signal from the torsional vibration signal to obtain the rotational speed fluctuation signal;

[0073] Step S3: Differentiate the rotational speed fluctuation signal to obtain an angular acceleration fluctuation signal;

[0074] Step S4: Perform high-pass filtering on the angular acceleration fluctuation signal to obtain the filtered angular acceleration fluctuation signal output by the engine.

[0075] Step 103: Measure the total moment of inertia of the engine rotating components according to the structure of the vehicle engine rotating components, where the engine rotating components include a belt pulley, a timing sprocket, a crankshaft, a piston connecting rod group, a flywheel, and a clutch housing.

[0076] In this embodiment, measure and calculate the moment of inertia values of the belt pulley, the timing sprocket, the crankshaft, the piston connecting rod group, the flywheel, and the clutch housing. The moment of inertia value of the piston connecting rod group is measured and calculated by the equivalent energy method, and the moment of inertia values of the remaining rotating components are directly measured by digital models. After accumulating the moment of inertia values of the engine rotating components, the total moment of inertia of the engine rotating components is obtained.

[0077] Specifically, the equivalent energy method used to calculate the moment of inertia value of the piston connecting rod group is as follows:

[0078] Let the mass of the connecting rod be m1, the mass of the piston be m2, the length of the connecting rod be L, the crank radius be r, and the length from the centroid of the connecting rod to the center point of the small end of the connecting rod be L a , and the crankshaft speed be ω. Then the moment of inertia of the crank connecting rod mechanism can be calculated by the following formula:

[0079]

[0080] Among them, m a , m b are the masses of the piston connecting rod mechanism equivalent to the small end and the big end of the connecting rod respectively, and can be calculated by the following formula:

[0081]

[0082] It can be seen from the calculation formula that the moment of inertia of the crank connecting rod mechanism is related to the crankshaft angle, and its equivalent moment of inertia can take the average value of the instantaneous moments of inertia at each moment within a working cycle, that is:

[0083]

[0084]

[0085] In this embodiment, the total moment of inertia of the engine rotating components of the rear driving force transmission system of the 4-cylinder engine is measured and calculated to be 0.14 kg / m 2 .

[0086] Step 104: Obtain the torsional vibration excitation load of the power transmission system through the vector operation of the angular acceleration fluctuation filtering signal output by the engine and the total moment of inertia of the rotating components of the engine.

[0087] In this embodiment, step 104 is specifically as follows:

[0088] Calculate and obtain the torsional vibration excitation load T of the power transmission system according to the following formula t :

[0089]

[0090] where J e is the total moment of inertia of the rotating components of the engine, is the angular acceleration fluctuation filtering signal output by the engine.

[0091] In this embodiment, partial time node data of the torsional vibration excitation load of the power transmission system is shown in Table 1, and the change trend of all its data is as Figure 3 shown, Figure 3 is the torsional vibration excitation load diagram extracted by a method and system for extracting the torsional vibration excitation load of a power transmission system provided by the present invention. The torsional vibration excitation load of the power transmission system extracted by the method of the present invention eliminates the constant part in the engine torque and only extracts the fluctuating torque part, so the extracted load fluctuates.

[0092] Table 1 Partial time node data of the torsional vibration excitation load of the power transmission system

[0093]

[0094]

[0095] Step 201: Conduct a torsional vibration test on the input end of the rear axle under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal of the input end of the rear axle.

[0096] The selection of the engine speed range and the actual operating conditions in the torsional vibration test of the input end of the rear axle correspond to step 101 in Embodiment 1 of the specification.

[0097] The torsional vibration test of the input end of the rear axle is carried out with a laser torsional vibration sensor. During the test, a reflective code tape or code disk is pasted on the measured surface, and the laser should be perpendicular to the measured surface. The distance between the sensor and the measured surface is preferably 2 - 5 mm. A tooling is designed during the test to fix the laser emission and reception device.

[0098] Step 202: Load the extracted torsional vibration excitation load of the power transmission system into the lumped parameter simulation analysis model of the power transmission system torsional vibration, conduct torsional vibration forced response simulation analysis, calculate the rotational speed fluctuations at the engine flywheel end and the input end of the rear axle, perform Fourier transform and order extraction, and obtain the rotational speed fluctuation engine ignition order slice components at the engine flywheel end and the input end of the rear axle in the simulation experiment.

[0099] In this embodiment, the extracted torsional vibration excitation load of the power transmission system is loaded into the lumped parameter simulation analysis model of the power transmission system torsional vibration to conduct torsional vibration forced response simulation analysis. To ensure the accuracy of the simulation analysis, the lumped parameter modeling considers the coupling effect between the power transmission system and the rear suspension system (coupled through the rear drive axle).

[0100] Step 203: Process the rotational speed fluctuation data of the torsional vibration signals output by the engine and the torsional vibration signals at the input end of the rear axle to obtain the rotational speed fluctuation signals at the engine flywheel end and the input end of the rear axle. Perform Fourier transform and order slicing on the rotational speed fluctuation signals to obtain the ignition order components of the rotational speed fluctuations at the engine flywheel end and the input end of the rear axle in the test experiment with respect to the engine speed.

[0101] In this embodiment, torsional vibration signals are obtained at the engine flywheel end and the input end of the rear axle through torsional vibration testing. After passing through steps S1 - S2 of rotational speed fluctuation data processing, the rotational speed fluctuation signals at the engine flywheel end and the input end of the rear axle are obtained. The time-domain curve graphs of the rotational speed fluctuations at the engine flywheel end and the input end of the rear axle are as Figure 4 shown. At the engine flywheel end, in the time periods of 0 - 9 s and above 16 s, the rotational speed fluctuation is more obvious compared to the time period of 9 - 16 s; at the input end of the rear axle, in the time periods of 0 - 11 s and above 15 s, the rotational speed fluctuation is more obvious compared to the time period of 11 - 15 s.

[0102] Step 204: Compare the rotational speed fluctuation engine ignition order slice components at the engine flywheel end in the simulation experiment with the ignition order components of the rotational speed fluctuations at the engine flywheel end in the test experiment with respect to the engine speed; compare the rotational speed fluctuation engine ignition order slice components at the input end of the rear axle in the simulation experiment with the ignition order components of the rotational speed fluctuations at the input end of the rear axle in the test experiment with respect to the engine speed.

[0103] In this embodiment, frequency-domain conversion and second-order order slicing are respectively performed on the time-domain results of the rotational speed fluctuations at the engine flywheel end and the input end of the rear axle of the power transmission system obtained from the simulation experiment and the test experiment. The comparison of the rotational speed fluctuation torsional vibration engine ignition order slice in the simulation experiment at the engine flywheel end is as Figure 5As shown, the data obtained from the simulation experiment and the test experiment are basically the same. The changing trends of the curves are the same, the corresponding rotational speeds of the peaks and valleys are the same, and the difference between the two is small. The envelope line is less than 5%. This shows that the extracted torsional vibration excitation load has a small gap with the actual torsional vibration excitation load, and the extracted torsional vibration excitation load can be used for the subsequent torsional vibration lumped parameter forced response simulation analysis. Comparison of the torsional vibration engine ignition order slice simulation test of the rotational speed fluctuation torsional vibration at the input end of the engine rear axle, as Figure 6 shown. It can be seen from the figure that the changing trends of the two curves are the same, the corresponding rotational speeds of the peaks and valleys are the same, and at the same time the difference between the two is small. The envelope line is less than 10%. The extracted torsional vibration excitation load of the power transmission system meets the accuracy requirements of the torsional vibration lumped parameter simulation analysis.

[0104] Through the comparison and analysis of the torsional vibration test and simulation analysis of the power transmission system, the accuracy and feasibility of extracting the torsional vibration excitation load of the power transmission system by this method and conducting the torsional vibration lumped parameter forced response simulation analysis are further determined. The torsional vibration excitation load of the power transmission system extracted by this method can also be used to conduct the torsional vibration forced response simulation analysis and the torsional vibration mode simulation analysis, etc., to further discover potential torsional vibration risks and solve torsional vibration problems. The accuracy of the torsional vibration simulation results is high. Further, through the torsional vibration parameter sensitivity simulation analysis, it can provide optimization guidance for solving the torsional vibration problems of the power transmission system and seek more efficient and lower-cost solutions to torsional vibration problems.

[0105] Embodiment 2

[0106] Correspondingly, referring to Figure 7 , Figure 7 is a schematic structural diagram of Embodiment 2 of the torsional vibration excitation load extraction system of the power transmission system provided by the present invention. As Figure 7 shown, the torsional vibration excitation load extraction system includes: a torsional vibration signal acquisition module 701, a torsional vibration signal data processing module 702, a running component rotational inertia measurement module 703, and a torsional vibration excitation load extraction module 704. The specific details of each device unit are as follows:

[0107] Among them, the torsional vibration signal acquisition module 701 is used to perform torsional vibration tests on the engine flywheel end under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine;

[0108] The torsional vibration signal acquisition module includes: a sensor setting unit 7011 and an actual condition torsional vibration test unit 7012;

[0109] Among them, the sensor setting unit 7011 is configured to set an electromagnetic torsional vibration sensor on the engine flywheel housing, collect the torsional vibration electrical signal at the engine flywheel end through the electromagnetic torsional vibration sensor, perform analog-to-digital conversion on the torsional vibration electrical signal at the engine flywheel end, and obtain the torsional vibration signal output by the engine; the actual working condition torsional vibration test unit 7012 is configured to perform a torsional vibration test on the engine flywheel end according to a preset engine speed range and the corresponding transmission gear in the actual operating condition, and obtain the torsional vibration signal output by the engine during the torsional vibration test of the actual operating condition of the whole vehicle;

[0110] In this embodiment, the sensor setting unit 7011 includes an electromagnetic torsional vibration sensor, a laser torsional vibration sensor, a laser sensor code disk, a code strip, and a data acquisition device. Among them, the electromagnetic torsional vibration sensor is used to test the torsional vibration signal output by the engine, the laser torsional vibration sensor is used to test the torsional vibration signal at the input end of the rear axle, the laser sensor code disk and the code strip are used in cooperation with the laser torsional vibration sensor, and the data acquisition device is used to collect and record the electrical signals generated by the sensors and complete the conversion of electrical signals to physical signals.

[0111] In this embodiment, the actual working condition torsional vibration test unit 7012 includes a data acquisition device, which is configured to perform a torsional vibration test on the actual operating condition of the whole vehicle according to a preset engine speed range and the corresponding transmission gear in the actual operating condition, and collect relevant data.

[0112] The torsional vibration signal data processing module 702 is configured to perform rotational speed fluctuation data processing on the torsional vibration signal to obtain an angular acceleration fluctuation filtered signal output by the engine;

[0113] The torsional vibration signal data processing module includes: a rotational speed extraction unit 7021, a rotational speed fluctuation calculation unit 7022, a differential calculation unit 7023, and a filtering unit 7024;

[0114] The rotational speed extraction unit 7021 is configured to extract the rotational speed signal of the engine at one pulse from the torsional vibration signal according to a preset rotational speed conversion function (TACHO_MOMENTS_TO_RPM function); the rotational speed fluctuation calculation unit 7022 is configured to subtract the rotational speed signal from the torsional vibration signal to obtain a rotational speed fluctuation signal; the differential calculation unit 7023 is configured to perform differentiation on the rotational speed fluctuation signal to obtain an angular acceleration fluctuation signal; the filtering unit 7024 is configured to perform high-pass filtering on the angular acceleration fluctuation signal to obtain an angular acceleration fluctuation filtered signal output by the engine.

[0115] In this embodiment, the torsional vibration signal data processing module 702 includes a data analysis device, which is configured to perform rotational speed fluctuation data processing on the torsional vibration signal.

[0116] The running component moment of inertia measurement module 703 is used to measure the total moment of inertia of the running components of the vehicle engine according to the structure of the running components of the vehicle engine. The running components of the engine include a belt pulley, a timing sprocket, a crankshaft, a piston connecting rod group, a flywheel, and a clutch housing.

[0117] In this embodiment, according to the structure of the running components of the vehicle engine, the moment of inertia values of the belt pulley, the timing sprocket, the crankshaft, the piston connecting rod group, the flywheel, and the clutch housing are measured and calculated. After accumulating the moment of inertia values of the running components of the engine, the total moment of inertia of the running components of the engine is obtained. Among them, the moment of inertia value of the piston connecting rod group is measured and calculated by the equivalent energy method, and the moment of inertia values of the remaining running components are directly measured by digital models.

[0118] In this embodiment, the running component moment of inertia measurement module 703 includes a data analysis device for measuring and calculating the total moment of inertia of the running components of the engine.

[0119] The torsional vibration excitation load extraction module 704 is used to obtain the torsional vibration excitation load of the power transmission system through the vector operation of the angular acceleration fluctuation filtering signal output by the engine and the total moment of inertia of the running components of the engine. Specifically, according to the following formula, the torsional vibration excitation load T of the power transmission system is calculated t :

[0120]

[0121] Among them, J e is the total moment of inertia of the running components of the engine, is the angular acceleration fluctuation filtering signal output by the engine.

[0122] In this embodiment, the torsional vibration excitation load extraction module 704 includes a data analysis device for calculating and extracting the torsional vibration excitation load of the power transmission system.

[0123] The more detailed working principle and process of this torsional vibration excitation load extraction system can but are not limited to refer to the content recorded above.

[0124] By conducting torsional vibration tests under actual operating conditions, various actual factors that affect the torsional vibration of the power transmission system are comprehensively considered, such as engine output torque excitation, additional torque excitation of the non-uniform velocity universal joint of the drive shaft, clearance of the transmission system, and fluctuations in the vehicle load. Based on this, the total moment of inertia of the rotating components of the engine is calculated. Then, through the vector operation of the angular acceleration fluctuation filtering signal and the total moment of inertia of the rotating components of the engine, the torsional vibration excitation load of the power transmission system is obtained. During the entire process of extracting the torsional vibration excitation load, only the processing of rotational speed fluctuation data and vector operation are involved, and there is no need to establish a complex engine output torque excitation model. The method is simple, simplifies the excitation extraction process, has strong applicability and reliability, and can also be applied to the analysis of torsional vibration problems of electric vehicles.

[0125] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. In particular, for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for extracting torsional vibration excitation load of a power transmission system, characterized in that, The extraction method includes: Under the actual operating conditions of the whole vehicle, conduct torsional vibration testing on the flywheel end of the engine to obtain the torsional vibration signal output by the engine; Perform rotational speed fluctuation data processing on the torsional vibration signal to obtain the filtered angular acceleration fluctuation signal output by the engine; According to the structure of the engine operating components of the whole vehicle, measure the total moment of inertia of the engine operating components, and the engine operating components include belt pulleys, timing sprockets, crankshafts, piston connecting rod groups, flywheels, and clutch housings; Through the vector operation of the filtered angular acceleration fluctuation signal output by the engine and the total moment of inertia of the engine operating components, obtain the torsional vibration excitation load of the power transmission system; The step of, according to the structure of the engine operating components of the whole vehicle, measuring the total moment of inertia of the engine operating components, where the engine operating components include belt pulleys, timing sprockets, crankshafts, piston connecting rod groups, flywheels, and clutch housings, specifically is: Measure and calculate the moment of inertia values of the belt pulley, timing sprocket, crankshaft, piston connecting rod group, flywheel, and clutch housing, and after accumulating the moment of inertia values of the engine operating components, obtain the total moment of inertia of the engine operating components; Among them, the moment of inertia value of the piston connecting rod group is measured and calculated by the equivalent energy method, and the moment of inertia values of the remaining operating components are directly measured by digital models; The step of, through the vector operation of the filtered angular acceleration fluctuation signal output by the engine and the total moment of inertia of the engine operating components, obtaining the torsional vibration excitation load of the power transmission system, specifically is: The torsional vibration excitation load T of the power transmission system is calculated according to the following formula t :[[]]END]] Among them, J e is the total moment of inertia of the rotating components of the engine, is the filtered angular acceleration fluctuation signal output by the engine; Among them, the specific equivalent energy method used to calculate the moment of inertia value of the piston connecting rod group is: Among them, m1 is the mass of the connecting rod, m2 is the mass of the piston, L is the length of the connecting rod, r is the crank radius, and L a is the length from the centroid of the connecting rod to the center point of the small end of the connecting rod, ω is the crankshaft speed, m a , m b are the masses of the piston connecting rod mechanism equivalent to the small end and the big end of the connecting rod respectively; J t is the moment of inertia of the crank connecting rod mechanism; n is the total number of moments in the working cycle.

2. The torsional vibration excitation load extraction method for the power transmission system according to claim 1, characterized in that The step of performing rotational speed fluctuation data processing on the torsional vibration signal to obtain the filtered angular acceleration fluctuation signal output by the engine, specifically is: According to a preset rotational speed conversion function, extract the rotational speed signal of the engine at one pulse from the torsional vibration signal; Subtract the rotational speed signal from the torsional vibration signal to obtain a rotational speed fluctuation signal; Differentiate the rotational speed fluctuation signal to obtain an angular acceleration fluctuation signal; Perform high-pass filtering on the angular acceleration fluctuation signal to obtain the filtered angular acceleration fluctuation signal output by the engine.

3. The torsional vibration excitation load extraction method for the power transmission system according to claim 1, characterized in that The step of, under the actual operating conditions of the whole vehicle, conducting torsional vibration testing on the flywheel end of the engine to obtain the torsional vibration signal output by the engine, specifically is: According to a preset engine rotational speed range and the corresponding transmission gear in the actual operating conditions, conduct torsional vibration testing on the flywheel end of the engine for the torsional vibration testing of the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine; Among them, the preset engine rotational speed range is selected to cover the rotational speed range where torsional vibration problems occur in the whole vehicle under the actual operating conditions, and the transmission gear of the corresponding rotational speed range under the actual operating conditions is selected for the torsional vibration testing; The actual operating conditions of the whole vehicle include a gentle acceleration driving condition, a rapid acceleration driving condition, and a deceleration driving condition.

4. The method for extracting torsional vibration excitation load of the power transmission system according to claim 3, characterized in that The step of obtaining the torsional vibration signal output by the engine, specifically is: An electromagnetic torsional vibration sensor is provided on the engine flywheel housing. The torsional vibration electrical signal at the engine flywheel end is collected through the electromagnetic torsional vibration sensor, and the torsional vibration electrical signal at the engine flywheel end is subjected to analog-to-digital conversion to obtain the torsional vibration signal output by the engine. Among them, the center point of the front end face of the electromagnetic torsional vibration sensor is directly opposite to the tooth surface of the engine flywheel teeth, and the distance between the center point of the end face and the measured tooth surface is 1-2 mm.

5. The torsional vibration excitation load extraction method for the power transmission system according to claim 1, characterized in that The torsional vibration test is carried out on the engine flywheel end under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine. Specifically: By loading a simple multi-rigid body model of engine multi-body dynamics, corresponding geometric parameters and inertia parameters of the crank connecting rod mechanism are input under the actual operating conditions of the whole vehicle, and the in-cylinder pressure test data of each cylinder measured on the test bench is loaded in the multi-body dynamics simple multi-rigid body model. The torsional vibration signal output by the engine crankshaft is extracted through simulation calculation.

6. A torsional vibration excitation load extraction system for a power transmission system, characterized in that, Including: A torsional vibration signal acquisition module, a torsional vibration signal data processing module, a rotational inertia measurement module of the rotating components, and a torsional vibration excitation load extraction module; Among them, the torsional vibration signal acquisition module is used to carry out a torsional vibration test on the engine flywheel end under the actual operating conditions of the whole vehicle to obtain the torsional vibration signal output by the engine; The torsional vibration signal data processing module is used to process the torsional vibration signal for rotational speed fluctuation data to obtain the filtered signal of the angular acceleration fluctuation output by the engine; The rotational inertia measurement module of the rotating components is used to measure the total value of the rotational inertia of the engine rotating components according to the structure of the whole vehicle engine rotating components. The engine rotating components include a belt pulley, a timing sprocket, a crankshaft, a piston connecting rod group, a flywheel, and a clutch housing; The torsional vibration excitation load extraction module is used to obtain the torsional vibration excitation load of the power transmission system through the vector operation of the filtered signal of the angular acceleration fluctuation output by the engine and the total value of the rotational inertia of the engine rotating components; Measure and calculate the rotational inertia values of the belt pulley, timing sprocket, crankshaft, piston connecting rod group, flywheel, and clutch housing, and after accumulating the rotational inertia values of the engine rotating components, obtain the total value of the rotational inertia of the engine rotating components; among them, the rotational inertia value of the piston connecting rod group is measured and calculated by the equivalent energy method, and the rotational inertia values of the remaining rotating components are directly measured by digital models; The torsional vibration excitation load extraction module, specifically: Calculate the torsional vibration excitation load T of the power transmission system according to the following formula t : Among them, J e is the total moment of inertia of the rotating components of the engine, is the filtered angular acceleration fluctuation signal output by the engine; Among them, the equivalent energy method used to calculate the rotational inertia value of the piston connecting rod group is specifically: Among them, m1 is the mass of the connecting rod, m2 is the mass of the piston, L is the length of the connecting rod, r is the crank radius, and L a is the length from the centroid of the connecting rod to the center point of the small end of the connecting rod, ω is the crankshaft speed, m a , m b are the masses of the piston connecting rod mechanism equivalent to the small end and the big end of the connecting rod respectively; J t is the moment of inertia of the crank connecting rod mechanism; n is the total number of moments in the working cycle.

7. The torsional vibration excitation load extraction system of the power transmission system according to claim 6, characterized in that, The torsional vibration signal acquisition module includes: a sensor setting unit and an actual condition torsional vibration test unit; Among them, the sensor setting unit is used to set an electromagnetic torsional vibration sensor on the engine flywheel housing, collect the torsional vibration electrical signal at the engine flywheel end through the electromagnetic torsional vibration sensor, and perform analog-to-digital conversion on the torsional vibration electrical signal at the engine flywheel end to obtain the torsional vibration signal output by the engine; the actual condition torsional vibration test unit is used to carry out a torsional vibration test on the engine flywheel end under the actual operating conditions of the whole vehicle according to the preset engine speed range and the corresponding transmission gear in the actual operating conditions, and obtain the torsional vibration signal output by the engine. The torsional vibration signal data processing module includes: a rotational speed extraction unit, a rotational speed fluctuation calculation unit, a differential calculation unit, and a filtering unit; Among them, the rotational speed extraction unit is used to extract the rotational speed signal of the engine at one pulse from the torsional vibration signal according to a preset rotational speed conversion function; the rotational speed fluctuation calculation unit is used to subtract the rotational speed signal from the torsional vibration signal to obtain a rotational speed fluctuation signal; the differential calculation unit is used to perform differentiation on the rotational speed fluctuation signal to obtain an angular acceleration fluctuation signal; the filtering unit is used to perform high-pass filtering on the angular acceleration fluctuation signal to obtain the angular acceleration fluctuation filtered signal output by the engine.

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