A method and device for detecting torsional vibration signals in the power-train angle domain

Abstract

The present invention provides a method and device for detecting torsional vibration signals in the angle domain of a powertrain, including the following steps: collecting the pulse signal of the engine camshaft signal disk through a camshaft position sensor; collecting the pulse signal of the engine crankshaft signal disk through a crankshaft position sensor; generating an engine crankshaft operating angle domain signal that changes with time based on the engine camshaft signal disk pulse signal and the engine crankshaft signal disk pulse signal; collecting the flywheel signal tooth pulse signal through a flywheel end sensor; generating a flywheel end angular displacement signal that changes with time based on the flywheel signal tooth pulse signal; integrating the angle domain signals and angular displacement signals at the same moment in the engine crankshaft operating angle signal that changes with time and the angular displacement signal that changes with time to obtain a torsional vibration signal that changes with the engine operating angle. The structure of the present invention is simple, realizing relatively low cost for detecting torsional vibration signals in the angle domain of the powertrain, and the signals are firm and reliable.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine testing, and particularly relates to a method and device for detecting torsional vibration signals in the angular domain of a powertrain. Background Art

[0002] Currently, for powertrain torsional vibration measurement, a code strip is mostly used. The code strip is installed at the transmission end and the front end of the crankshaft, and only the torsional vibration data at the front end of the crankshaft and the output end of the transmission can be measured. The torsional vibration data at the output end of the engine and the input end of the transmission cannot be measured, and the torsional vibration excitation data at the output end of the engine cannot be obtained. At the same time, when measuring by the code strip method on a vehicle, it is difficult to install the laser speed sensor and it is easily affected by vibration. Due to the limited installation of the sensor, the engine angular domain signal cannot be collected, and thus the torsional vibration data in the angular domain of the powertrain cannot be collected. Therefore, the existing testing methods are not applicable to the detection of torsional vibration signals in the angular domain of the powertrain due to the above defects. Summary of the Invention

[0003] The purpose of the present invention is to solve the deficiencies existing in the above background art, and provide a method and device for detecting torsional vibration signals in the angular domain of a powertrain, which has a simple structure, low cost, reliable signals, solves the technical problems in the industry, and is easy to be popularized and used in the field of powertrain testing.

[0004] The technical solution adopted by the present invention is: a method for detecting torsional vibration signals in the angular domain of a powertrain, comprising the following steps:

[0005] Collect the pulse signal of the engine camshaft signal disk through the camshaft position sensor;

[0006] Collect the pulse signal of the engine crankshaft signal disk through the crankshaft position sensor;

[0007] Generate an engine crankshaft operating angular domain signal that changes with time through the engine camshaft signal disk pulse signal and the engine crankshaft signal disk pulse signal;

[0008] Collect the pulse signal of the flywheel signal teeth through the flywheel end sensor; generate a flywheel end angular displacement signal that changes with time based on the flywheel signal tooth pulse signal;

[0009] Integrate the angular domain signals and angular displacement signals at the same moment in the engine crankshaft operating angle signal that changes with time and the angular displacement signal that changes with time to obtain a torsional vibration signal that changes with the engine operating angle.

[0010] In the above technical solution, the process of generating an engine crankshaft operating angular domain signal that changes with time through the engine camshaft signal disk pulse signal and the engine crankshaft signal disk pulse signal includes:

[0011] Find the moment when the first cylinder of the engine runs to the top dead center position according to the pulse signal of the engine camshaft signal disk, and define the crankshaft angle represented by the crankshaft signal corresponding to this moment as the initial angle. The value of the initial angle is determined by the tooth ring structures of the camshaft signal disk and the crankshaft signal disk. Calculate the crankshaft angle corresponding to each high-level trigger moment of the crankshaft signal disk based on the initial angle of the crankshaft signal, the crankshaft angle distribution mode of the signal teeth of the crankshaft signal disk, and the high-level trigger moment of the crankshaft signal disk, so as to obtain the engine crankshaft operating angle signal that changes with time.

[0012] In the above technical solution, the process of finding the moment when the first cylinder of the engine runs to the top dead center position according to the pulse signal of the engine camshaft signal disk includes:

[0013] The camshaft position sensor continuously detects the state of the camshaft signal disk, outputs a high level when facing the signal teeth of the camshaft signal disk, and outputs a low level when facing the space between two adjacent signal teeth of the camshaft signal disk;

[0014] Record the high-level trigger moment;

[0015] When the duration of a certain high level and the previous high level is less than 1 / 2 of the duration of the previous group of adjacent high levels, determine that the moment corresponding to this high level is the moment when the first cylinder of the engine runs to the top dead center position

[0016] The present invention analyzes the pulse signal of the camshaft position sensor to detect the moment when the first cylinder of the engine runs to the top dead center position, and determines the top dead center moment of the first cylinder in the angle domain of the present invention through the cylinder discrimination signal of the engine itself to ensure the detection accuracy. Convert the geometric characteristics of the signal disk into the time domain, and use the difference in the high-level duration to judge the moment when the first cylinder runs to the top dead center position, which is simple and practical.

[0017] In the above technical solution, the process of calculating the crankshaft angle corresponding to each high-level trigger moment of the crankshaft signal disk based on the initial angle of the crankshaft signal, the crankshaft angle distribution mode of the signal teeth of the crankshaft signal disk, and the high-level trigger moment of the crankshaft signal disk includes:

[0018] The tooth ring of the crankshaft signal disk is provided with a tooth missing area; the crankshaft position sensor continuously detects the state of the crankshaft signal disk, outputs a high level when facing the signal teeth of the crankshaft signal disk, and outputs a low level when facing the space between two adjacent signal teeth of the crankshaft signal disk;

[0019] Take the moment when the first cylinder of the engine runs to the top dead center position As the initial moment of the engine crankshaft operating angle signal And take the value of the initial angle as the value α0 of the crankshaft angle number at this moment; take the initial moment as the starting moment, and the subsequent recorded high-level trigger moments of the crankshaft signal disk are Right now The crankshaft angle corresponding to each triggering moment is (a0, a1, ... a n ); Each triggering moment indicates that the corresponding signal tooth position has been reached; a n+1 =a n +A°;A means The signal tooth reached at the moment The angle difference of the signal teeth reached at the moment; let the duration of two adjacent high and low levels be When At , the value of A is the crankshaft angle corresponding to the missing tooth area; at other times, the value of A is the crankshaft angle corresponding to each signal tooth;

[0020] The engine crankshaft operating angle signal that changes with time is expressed as

[0021] The present invention obtains the initial angle based on the top dead center position obtained by analyzing the camshaft signal, and then obtains the angle domain signal that changes with time through crankshaft signal analysis, which is beneficial to the engine's own crankshaft signal disk missing tooth signal to determine the initial recording moment of the angle domain of the present invention, and then facilitates the teeth with evenly spaced angles to convert the time domain into the angle domain. The analysis formula assigns an angle value to each high-level trigger moment, which is simple and practical, has high accuracy and saves calculation costs.

[0022] In the above technical solution, the process of generating a flywheel end angular displacement signal that varies with time based on the flywheel signal tooth pulse signal includes:

[0023] Record the changing moment of the flywheel signal tooth pulse signal; calculate the angular velocity signal corresponding to each changing moment according to the signal tooth distribution mode of the flywheel signal disk and the time difference of each changing moment, and then obtain the flywheel end angular displacement signal that changes with time.

[0024] In the above technical solution, a Hall-type speed sensor is installed on the flywheel housing of the engine as a flywheel end sensor; the Hall-type speed sensor triggers a high level when facing the signal teeth of the flywheel signal disk, and triggers a low level when facing between two adjacent signal teeth of the flywheel signal disk; when the engine is running, the Hall-type speed sensor generates a set of rectangular wave signals;

[0025] Record the moment of the rising edge of the rectangular wave signal That is And calculate each moment The corresponding angular velocity ω l ;in:

[0026] B represents the number of teeth on the flywheel signal plate;

[0027] Perform high-pass filtering on the angular velocity signal to retain the high-frequency fluctuation component signal of the angular velocity The high-frequency fluctuation component of the angular velocity signal Perform point-by-point integration to obtain the angular displacement signal Thus, an angular displacement signal that changes with time is obtained, that is

[0028] The present invention generates an angular displacement signal over time by analysis. Using the engine starting ring gear as the engine flywheel signal disk, there is no need to additionally arrange a signal generation unit. The advantage of the analysis formula is that it is conducive to integrating the angular velocity into angular displacement, which is simple and practical, with high accuracy and saving calculation costs at the same time.

[0029] The present invention also provides a power-train angle-domain torsional vibration signal detection device, including a signal acquisition system and a data processing system; the signal acquisition system includes a camshaft signal acquisition unit, a crankshaft signal acquisition unit, and a flywheel-end signal acquisition unit; the data processing system includes an angle-domain generation module, an angular velocity generation module, a torsional vibration generation module, and an angle-domain torsional vibration generation module;

[0030] The camshaft signal acquisition unit acquires the engine camshaft signal disk pulse signal;

[0031] The crankshaft signal acquisition unit acquires the engine crankshaft signal disk pulse signal;

[0032] The flywheel-end signal acquisition unit acquires the flywheel signal tooth pulse signal;

[0033] The angle-domain generation module generates an engine crankshaft operating angle-domain signal based on the crankshaft signal disk pulse signal and the crankshaft signal disk pulse signal,

[0034] The angular velocity generation module generates an engine flywheel-end angular velocity signal based on the flywheel signal tooth pulse signal,

[0035] The torsional vibration generation module generates an engine flywheel-end angular displacement signal based on the flywheel-end angular velocity signal;

[0036] The angle-domain torsional vibration generation module integrates the engine crankshaft operating angle-domain signal and the flywheel-end angular displacement signal to generate a torsional vibration signal in the angle domain.

[0037] In the above technical solution, the camshaft signal acquisition unit includes a camshaft signal disk installed at the end of the camshaft and a camshaft position sensor installed on the cylinder head; the camshaft position sensor is arranged normally outside the camshaft signal disk, and there is a spacing between the sensing end of the camshaft position sensor and the tooth ring of the camshaft signal disk; the tooth ring of the camshaft signal disk is provided with a plurality of signal teeth, the spacing between each signal tooth is the same, the angle of one of the signal teeth is smaller than that of the other signal teeth, and the angles of the other signal teeth are the same; when the camshaft position sensor faces the signal teeth of the camshaft signal disk, it outputs a high level, and when it faces the space between two adjacent signal teeth of the camshaft signal disk, it outputs a low level.

[0038] In the above technical solution, the crankshaft signal acquisition unit includes a crankshaft signal disk installed outside the crankshaft damper and a crankshaft position sensor installed on the cylinder block; the crankshaft position sensor is arranged normally outside the crankshaft signal disk, and there is a spacing between the sensing end of the crankshaft position sensor and the tooth ring of the crankshaft signal disk; the tooth ring of the camshaft signal disk is provided with a plurality of signal teeth, the spacing between each signal tooth is the same, the angle of one of the signal teeth is smaller than that of the other signal teeth, and the angles of the other signal teeth are the same; when the camshaft position sensor faces the signal teeth of the camshaft signal disk, it outputs a high level, and when it faces the space between two adjacent signal teeth of the camshaft signal disk, it outputs a low level.

[0039] In the above technical solution, the flywheel end torsional vibration signal acquisition unit includes a flywheel signal disk installed outside the flywheel and a flywheel speed sensor installed on the flywheel housing; the flywheel speed sensor is arranged normally outside the flywheel signal disk, and there is a spacing between the sensing end of the flywheel speed sensor and the tooth ring of the flywheel signal disk; the gear of the flywheel signal disk has a plurality of uniformly distributed signal teeth; when the flywheel speed sensor faces the signal teeth of the flywheel signal disk, it triggers a high level, and when it faces the space between two adjacent signal teeth of the flywheel signal disk, it triggers a low level.

[0040] The beneficial effects of the present invention are as follows: The present invention ingeniously borrows the camshaft and crankshaft signal acquisition units of the engine itself, and uses the starting ring gear on the flywheel as the torsional vibration signal acquisition unit. After integration, a detection method and device for the torsional vibration signal in the angle domain of the powertrain are developed. The advantages of the installation method of the device of the present invention and signal acquisition are that the camshaft signal and the crankshaft signal are directly output from the camshaft signal and the crankshaft signal during the operation of the engine. In terms of hardware, only a Hall speed sensor is installed in the speed hole of the flywheel housing. The structure is simple, the cost is low, the signal is firm and reliable, and it is not affected by the bumps of the whole vehicle, the vibration of the engine and the external vibration, with strong adaptability and high measurement accuracy. The present invention identifies the positions of the camshaft, the crankshaft and the flywheel by analyzing the changes in the pulse signals output by the sensor, and then converts the pulse signals into angle domain signals and angular displacement signals according to the physical structures of the camshaft, the crankshaft and the flywheel, so as to obtain the torsional vibration signal in the angle domain, reducing the difficulty of signal acquisition while ensuring the accuracy of the signal and saving the calculation cost at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is the flowchart of the method of the present invention;

[0042] Figure 2 is the camshaft signal diagram in step 1.1 of the method of the present invention;

[0043] Figure 3 is the crankshaft signal diagram in step 1.2 of the method of the present invention;

[0044] Figure 4 is the flywheel end signal diagram in step 1.3 of the method of the present invention;

[0045] Figure 5 is the angle signal diagram changing with time in step 3.2 of the method of the present invention;

[0046] Figure 6 is the flywheel end angular velocity signal diagram in step 4.2 of the method of the present invention;

[0047] Figure 7 is the flywheel end angular velocity high-frequency component signal diagram in step 4.3 of the method of the present invention;

[0048] Figure 8 is the flywheel end angular displacement signal diagram in step 4.4 of the method of the present invention;

[0049] Figure 9 is the powertrain angle domain torsional vibration signal diagram in step 5 of the method of the present invention;

[0050] Figure 10 is the schematic diagram of the device of the present invention;

[0051] Figure 11 is the structural schematic diagram of the camshaft signal acquisition unit;

[0052] Figure 12 It is a schematic structural diagram of the crankshaft signal acquisition unit;

[0053] Figure 13 It is a schematic structural diagram of the flywheel end signal acquisition unit;

[0054] Among them, 1 - camshaft signal acquisition unit, 1a - camshaft signal disk, 1b - camshaft sensor, 2 - crankshaft signal acquisition unit, 2a - crankshaft signal disk, 2b - crankshaft sensor, 3 - flywheel end signal acquisition unit, 3a - flywheel signal disk, 3b - flywheel sensor, 4 - camshaft, 5 - crankshaft. Specific embodiments

[0055] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, which is convenient for clearly understanding the present invention, but they do not limit the present invention.

[0056] As Figure 10 shown, the present invention provides a power assembly angle domain torsional vibration signal detection device, including a signal acquisition system and a data processing system; the signal acquisition system includes a camshaft signal acquisition unit, a crankshaft signal acquisition unit and a flywheel end signal acquisition unit; the data processing system includes an angle domain generation module, an angular velocity generation module, a torsional vibration generation module and an angle domain torsional vibration generation module;

[0057] The camshaft signal acquisition unit acquires the engine camshaft signal disk pulse signal;

[0058] The crankshaft signal acquisition unit acquires the engine crankshaft signal disk pulse signal;

[0059] The flywheel end signal acquisition unit acquires the flywheel signal tooth pulse signal;

[0060] The angle domain generation module generates an engine crankshaft operating angle domain signal according to the crankshaft signal disk pulse signal and the crankshaft signal disk pulse signal,

[0061] The angular velocity generation module generates an engine flywheel end angular velocity signal according to the flywheel signal tooth pulse signal,

[0062] The torsional vibration generation module generates an engine flywheel end angular displacement signal according to the flywheel end angular velocity signal;

[0063] The angle domain torsional vibration generation module integrates the engine crankshaft operating angle domain signal and the flywheel end angular displacement signal to generate a torsional vibration signal in the angle domain.

[0064] In this specific embodiment, as Figure 11As shown in the figure, the camshaft signal acquisition unit 1 includes a cam signal disk 1a installed at the end of the camshaft and a camshaft position sensor 1b installed on the cylinder head; the camshaft position sensor 1b is arranged normally outside the cam signal disk, and the distance between the sensor head and the toothed ring is 3 mm; the cam signal disk 1a has 7 teeth, with 6 teeth evenly distributed, the tooth pitch is 60°, the 7th tooth is the top dead center signal tooth of cylinder 1 of the engine, and the interval from the 6th tooth is 9°; the input voltage of the camshaft position sensor 1b is 5V, the output voltage is 5V when approaching the tooth top of the cam signal disk, and the output voltage is 0V when leaving the tooth top of the cam signal disk.

[0065] As Figure 12 shown, the crankshaft signal acquisition unit 1 includes a crankshaft signal disk 2a installed outside the crankshaft damper and a crankshaft position sensor 2b installed on the cylinder block; the crankshaft position sensor 2b is arranged normally outside the crankshaft signal disk, and the distance between the crankshaft position sensor and the toothed ring of the crankshaft signal disk is 3 mm; the crankshaft signal disk 2a has 58 teeth, evenly distributed, the tooth pitch is 6°, the tooth bottom between the 58th tooth and the 1st tooth is 5 times that of the other tooth tops, and is used for cylinder discrimination of the top dead center of cylinder 1 of the engine; the input voltage of the crankshaft position sensor 2b is 5V, the output voltage is 5V when approaching the tooth top of the crankshaft signal disk, and the output voltage is 0V when leaving the tooth top of the crankshaft signal disk.

[0066] As Figure 13 shown, the flywheel end torsional vibration signal acquisition unit 3 includes a signal disk 3a installed outside the flywheel and a flywheel speed sensor 3b installed on the flywheel housing; the flywheel speed sensor 3b is arranged normally outside the flywheel signal disk, and the distance between the sensor head and the toothed ring is 3 mm; the flywheel signal disk 3a has 100 teeth, evenly distributed, and the tooth pitch is 3.6°; the input voltage of the flywheel speed sensor 3b is 5V, the output voltage is 5V when approaching the tooth top, the output voltage is 0V when leaving the tooth top and facing the tooth top, and the rising edge trigger voltage for angular velocity calculation and analysis is 3V.

[0067] The detection method of the power-train angle-domain torsional vibration signal detection device, as Figure 1 shown, includes the following steps:

[0068] S1, collecting the pulse signal of the engine camshaft signal disk through the camshaft position sensor;

[0069] S2, collecting the pulse signal of the engine crankshaft signal disk through the crankshaft position sensor;

[0070] S3, generating an engine crankshaft operating angle-domain signal that changes with time through the engine camshaft signal disk pulse signal and the engine crankshaft signal disk pulse signal;

[0071] S4, collecting the flywheel signal tooth pulse signal through the flywheel end sensor; generating a flywheel end angular displacement signal that changes with time based on the flywheel signal tooth pulse signal;

[0072] S5. Integrate the angular domain signal and the angular displacement signal at the same moment in the engine crankshaft operating angle signal that changes with time and the angular displacement signal that changes with time to obtain a torsional vibration signal that changes with the engine operating angle.

[0073] In step S1, collect the engine camshaft signal disk pulse signal Q through the camshaft position sensor 凸 , as Figure 2 shown.

[0074] Detect the moment when the engine's No. 1 cylinder runs to the top dead center position through data analysis The process includes the following steps:

[0075] S1.1 Collect the camshaft signal disk pulse signal: During operation, the camshaft position sensor continuously detects the state of the toothed ring of the camshaft signal disk. When the sensing end of the camshaft position sensor approaches the tooth surface of the toothed ring of the camshaft signal disk, it outputs a 5V high level, and when it leaves the tooth surface of the toothed ring of the camshaft signal disk, it outputs a 0V low level. The data is recorded as a rectangular wave Q of 0 - 5V 凸 , and the system sampling rate is 30KHz; as Figure 2 shown

[0076] S1.2 Calculate the moment when the engine's No. 1 cylinder runs to the top dead center of the cylinder block: As Figure 11 shown, the engine camshaft signal disk is evenly distributed with 6 signal teeth and 1 cylinder discrimination signal tooth. The evenly distributed signal teeth are spaced 60° apart, representing the moments of the top dead center positions of each cylinder. The No. 1 cylinder discrimination tooth is between the top dead center signal teeth of the No. 4 cylinder and the No. 1 cylinder. During operation, the system records the high level trigger moment of the camshaft signal disk as i.e. Let the duration of two adjacent high levels be i.e. the duration of the high level is When the duration of two adjacent high levels is less than 1 / 2 of the duration of the previous group of adjacent high levels, the engine's No. 1 cylinder runs to the top dead center position, i.e. when at this time, the moment is the moment when the No. 1 cylinder runs to the top dead center. The above method calculates the moment when the engine's No. 1 cylinder runs to the top dead center.

[0077] In step S2, collect the crankshaft signal disk pulse signal simultaneously with the camshaft signal: During operation, the crankshaft position sensor continuously detects the state of the toothed ring of the crankshaft signal disk. When it approaches the tooth surface of the crankshaft signal disk, it outputs a 5V high level, and when it leaves the tooth surface of the crankshaft signal disk, it outputs a 0V low level. The data is recorded as a rectangular wave Q of 0 - 5V 曲 , and the system sampling rate is 30KHz, as Figure 3 shown.

[0078] In step S3, the engine crankshaft signal disk pulse signal Q is collected through the crankshaft position sensor. 曲 The moment when the first cylinder of the engine runs to the top dead center position is used as the initial moment of the engine crankshaft running angle signal. And the initial rotation angle value is used as the value α0 of the crankshaft rotation angle number at this moment. Each tooth of the crankshaft signal disk corresponds to the engine crankshaft running rotation angle, and the trigger moment of each rising edge is The corresponding crankshaft rotation angle is α n , which is recorded as an angle domain signal changing with time, that is Specifically, it includes the following steps:

[0079] Convert the crankshaft signal disk pulse signal into an angle signal changing with time: The main function of the crankshaft signal disk of an electronically controlled engine is to record the crankshaft rotation angle and cooperate with the camshaft signal for cylinder discrimination and ignition. It is designed with a structure of 58 teeth missing 2 teeth, that is, the crankshaft signal disk has 58 signal teeth, each tooth represents 6°, and 2 teeth are missing for cylinder discrimination. In the present invention, the crankshaft signal is borrowed to generate an angle signal. Each tooth from No. 1 to No. 57 is set as a 6° crankshaft rotation angle, and the 58th tooth is set as an 18° crankshaft rotation angle, and the angles corresponding to the two missing teeth are filled to generate a complete 360° per revolution.

[0080] During operation, the system records the high-level trigger moment of the crankshaft signal disk as That is Set the duration of adjacent two high levels as That is, the high-level duration is When the duration of adjacent two high levels is greater than 2 times the duration of the previous group of adjacent high levels, that is, when is satisfied, this signal is identified as a missing tooth signal, representing an 18° crankshaft rotation angle, and the other 57 uniform gears represent a 6° crankshaft rotation angle. The value of α is determined by the camshaft signal disk and the crankshaft signal disk tooth ring structure 初始角 = -33°.

[0081] The crankshaft rotation angles represented by successive triggers are α0 = -33°. Since there are 2 missing tooth signals on the crankshaft signal disk, the last tooth represents a crankshaft rotation angle of 18°, that is

[0082]

[0083] For example Figure 5 As shown, finally, the engine crankshaft running angle signal changing with time is obtained:

[0084] In step S4, the flywheel signal disk pulse signal Q is collected through the flywheel sensor. 飞 (t0, Q0), (t1, Q1),......(t l , Q l); Generate an angular displacement signal over time from the flywheel pulse signals (t0, Q0), (t1, Q1),......(t l , Q l ) through data analysis as follows: As Figure 4 shown, it specifically includes the following steps:

[0085] S4.1 Install a Hall speed sensor on the engine flywheel housing. The Hall speed sensor triggers a high level of 5V when approaching the tooth top of the flywheel signal disk and a low level of 0V when leaving the tooth top of the flywheel signal disk. When the engine is running, a set of rectangular waves Q 飞 with a system sampling rate of 30KHz is generated.

[0086] S4.2 Convert the rectangular wave signal into an angular velocity signal: Set the rising edge speed trigger mode, that is, the rectangular wave signal rises from 0V to 5V to trigger speed recording, and the moment is which is The engine angular velocity is the angular displacement per unit time, that is, ω = θ / Δ t = 360° / A*Δt, where A is the number of teeth on the flywheel signal. In this invention, the number of teeth is 100, that is, A = 100. Deduce The acceleration signal changing with time is obtained by this method, that is, (t0, ω0), (t1, ω1),......(t l , ω l ), as Figure 6 shown.

[0087] S4.3 Apply a high-pass 5Hz filter to the angular velocity signal ω l to extract its high-frequency component signal; Apply a high-pass 5Hz filter to the angular velocity signal ω l to filter out the stable component of the angular velocity, that is, the engine speed signal, and retain the high-frequency fluctuation component signal of the angular velocity As Figure 7 shown.

[0088] S4.4 Integrate the high-frequency fluctuation component of the angular velocity signal point by point to obtain the angular displacement signal

[0089] According to the following formula: where R is the resolution, taking R = 1. The angular displacement signal changing with time can be obtained by this method, that is, As Figure 8 shown.

[0090] In step S5, integrate the angle signal and the angular displacement signal at the same moment to obtain the angular displacement signal changing with the engine operation angle, that is, AsFigure 9 As shown, the physical vibration parameters for characterizing torsional vibration in engineering are angular displacement, angular velocity, and angular acceleration. In the automotive field, the angular displacement parameter is usually used to measure the torsional vibration of the engine shafting. Therefore, the torsional vibration signal varying with the engine operating angle can be obtained through the above method.

[0091] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. A method for detecting torsional vibration signals in the angular domain of a powertrain, characterized in that: It includes the following steps: Collect the engine camshaft signal disk pulse signal through a camshaft position sensor; Collect the engine crankshaft signal disk pulse signal through a crankshaft position sensor; Generate an engine crankshaft operating angle domain signal that changes over time based on the engine camshaft signal disk pulse signal and the engine crankshaft signal disk pulse signal; Collect the flywheel signal tooth pulse signal through a flywheel end sensor; generate a flywheel end angular displacement signal that changes over time based on the flywheel signal tooth pulse signal; Integrate the angle domain signals and angular displacement signals at the same moment in the engine crankshaft operating angle signal that changes over time and the angular displacement signal that changes over time to obtain a torsional vibration signal that changes with the engine operating angle; The process of generating an engine crankshaft operating angle domain signal that changes over time based on the engine camshaft signal disk pulse signal and the engine crankshaft signal disk pulse signal includes: Find the moment when the engine's No. 1 cylinder runs to the top dead center position according to the engine camshaft signal disk pulse signal, and define the crankshaft angle represented by the crankshaft signal corresponding to this moment as the initial angle. Determine the initial angle value according to the camshaft signal disk and the crankshaft signal disk gear ring structure; calculate the crankshaft angle corresponding to each crankshaft signal disk high-level trigger moment according to the initial angle of the crankshaft signal, the signal tooth distribution mode of the crankshaft signal disk, and the crankshaft signal disk high-level trigger moment, so as to obtain an engine crankshaft operating angle signal that changes over time.

2. The method for detecting torsional vibration signals in the power-train angle domain according to claim 1, characterized in that: The process of finding the moment when the engine's No. 1 cylinder runs to the top dead center position according to the engine camshaft signal disk pulse signal includes: The camshaft position sensor continuously detects the state of the camshaft signal disk, outputs a high level when facing the signal teeth of the camshaft signal disk, and outputs a low level when facing the space between two adjacent signal teeth of the camshaft signal disk; Record the high-level trigger moment; When the duration of a high level is less than 1 / 2 of the duration of the previous group of adjacent high levels compared to the previous high level, it is determined that the moment corresponding to this high level is the moment when the first cylinder of the engine reaches the top dead center position.

3. A method for detecting torsional vibration signals in the angle domain of a powertrain according to claim 2, characterized in that: The process of calculating the crankshaft angle corresponding to each crankshaft signal disk high-level trigger moment according to the initial angle of the crankshaft signal, the crankshaft angle distribution mode of the signal teeth of the crankshaft signal disk, and the crankshaft signal disk high-level trigger moment includes: The gear ring of the crankshaft signal disk is provided with a tooth missing area; the crankshaft position sensor continuously detects the state of the crankshaft signal disk, outputs a high level when facing the signal teeth of the crankshaft signal disk, and outputs a low level when facing two adjacent signal teeth of the crankshaft signal disk; The moment when the first cylinder of the engine runs to the top dead center position As the initial moment of the engine crankshaft running angle signal And take the initial rotation angle value as the value α0 of the crankshaft rotation angle number at this moment; starting from the initial moment, the high-level trigger moment of the subsequent recorded crankshaft signal disk is That is The crankshaft rotation angle corresponding to each trigger moment is (a0, a1, …… a n ); each trigger moment indicates reaching the corresponding signal tooth position; a n+1 = a n + A°; A represents The angle difference between the signal tooth reached at the moment and The signal tooth reached at the moment; assume that the duration of adjacent high and low levels is When a certain happens, the value of A is the crankshaft rotation angle corresponding to the tooth missing area; at other moments, the value of A is the crankshaft rotation angle corresponding to each signal tooth; The engine crankshaft running angle signal varying with time is expressed as 4. A method for detecting torsional vibration signals in the angle domain of a powertrain according to claim 1, characterized in that: The process of generating a flywheel end angular displacement signal that changes over time based on the flywheel signal tooth pulse signal includes: Record the change moments of the flywheel signal tooth pulse signal; calculate the angular velocity signal corresponding to each change moment according to the signal tooth distribution mode of the flywheel signal disk and the time difference between each change moment, and then obtain a flywheel end angular displacement signal that changes over time.

5. The method for detecting the torsional vibration signal in the angle domain of a power assembly according to claim 4, characterized in that: Install a Hall type speed sensor on the engine flywheel housing as the flywheel end sensor; the Hall type speed sensor triggers a high level when facing the signal teeth of the flywheel signal disk, and triggers a low level when facing the space between two adjacent signal teeth of the flywheel signal disk; when the engine is running, the Hall type speed sensor generates a group of rectangular wave signals; Record the moment of the rising edge of the rectangular wave signal That is And calculate the corresponding angular velocity ω at each moment ; l ; Wherein: B represents the number of teeth of the flywheel signal disk; Perform high-pass filtering on the angular velocity signal to retain the high-frequency fluctuation component signal of the angular velocity The high-frequency fluctuation component of the angular velocity signal Perform point-by-point integration to obtain the angular displacement signal Thus, an angular displacement signal that changes with time is obtained, that is 6. A powertrain angular domain torsional vibration signal detection device, characterized in that: It includes a signal acquisition system and a data processing system; the signal acquisition system includes a camshaft signal acquisition unit, a crankshaft signal acquisition unit, and a flywheel end signal acquisition unit; the data processing system is composed of an angular domain generation module, an angular velocity generation module, a torsional vibration generation module, and an angular domain torsional vibration generation module; The camshaft signal acquisition unit acquires the pulse signal of the engine camshaft signal disk; The crankshaft signal acquisition unit acquires the pulse signal of the engine crankshaft signal disk; The flywheel end signal acquisition unit acquires the pulse signal of the flywheel signal teeth; The angular domain generation module generates the engine crankshaft operating angular domain signal according to the crankshaft signal disk pulse signal and the crankshaft signal disk pulse signal, The angular velocity generation module generates the engine flywheel end angular velocity signal according to the flywheel signal tooth pulse signal, The torsional vibration generation module generates the engine flywheel end angular displacement signal according to the flywheel end angular velocity signal; The angular domain torsional vibration generation module integrates the engine crankshaft operating angular domain signal and the flywheel end angular displacement signal to generate the torsional vibration signal in the angular domain; The described camshaft signal acquisition unit includes a camshaft signal disk installed at the end of the camshaft and a camshaft position sensor installed on the cylinder head; the camshaft position sensor is arranged normally outside the camshaft signal disk, and there is a spacing between the sensing end of the camshaft position sensor and the tooth ring of the camshaft signal disk; the tooth ring of the camshaft signal disk is provided with a number of signal teeth, and the spacing between each signal tooth is the same, and the angle of one of the signal teeth is smaller than that of the other signal teeth, and the angles of the other signal teeth are the same; when the camshaft position sensor faces the signal teeth of the camshaft signal disk, it outputs a high level, and when it faces the space between two adjacent signal teeth of the camshaft signal disk, it outputs a low level; The described crankshaft signal acquisition unit includes a crankshaft signal disk installed outside the crankshaft damper and a crankshaft position sensor installed on the cylinder block; the crankshaft position sensor is arranged normally outside the crankshaft signal disk, and there is a spacing between the sensing end of the crankshaft position sensor and the tooth ring of the crankshaft signal disk; the tooth ring of the crankshaft signal disk is provided with a number of signal teeth, and the angle of each signal tooth is the same, and the spacing between two adjacent signal teeth is greater than that of the other signal teeth, and the spacing between the other signal teeth and the adjacent signal teeth is the same; when the crankshaft position sensor faces the signal teeth of the crankshaft signal disk, it outputs a high level, and when it faces two adjacent signal teeth of the crankshaft signal disk, it outputs a low level.

7. The torsional vibration signal detection device for a powertrain in an angular domain according to claim 6, characterized in that: The described flywheel end torsional vibration signal acquisition unit includes a flywheel signal disk installed outside the flywheel and a flywheel speed sensor installed on the flywheel housing; the flywheel speed sensor is arranged normally outside the flywheel signal disk, and there is a spacing between the sensing end of the flywheel speed sensor and the tooth ring of the flywheel signal disk; the gear of the flywheel signal disk has a number of evenly distributed signal teeth; when the flywheel speed sensor faces the signal teeth of the flywheel signal disk, it triggers a high level, and when it faces the space between two adjacent signal teeth of the flywheel signal disk, it triggers a low level.

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