Centrifugal pendulum damper vibration testing device and testing method

Abstract

This invention relates to a vibration testing device and method for a centrifugal pendulum vibration damper. The device includes: a servo motor, whose output shaft is connected to the input end of the vibration damper under test via an input flange, for simulating the power input and order torsional vibration excitation of an engine crankshaft; a hysteresis brake, whose input shaft is connected to the output end of the vibration damper under test via an output flange, capable of applying dynamic alternating load torque for braking output torque; a transparent observation window sealed by an acrylic plate on the primary flywheel of the centrifugal pendulum vibration damper; highly reflective reflective markers set on the flat, non-contact surfaces of the pendulum blocks and rollers; a laser Doppler vibration meter fixed to the outside of the primary flywheel of the centrifugal pendulum, with its optical path aligned with the reflective markers within the window; and a power control unit connected to the laser Doppler vibration meter and input / output torque and speed sensors for signal processing. This invention achieves non-contact measurement of the centrifugal pendulum's operating state, facilitating vibration damper performance verification and fault diagnosis.

Description

Technical Field

[0001] This invention relates to the field of rotating machinery vibration testing technology, specifically to a dynamic characteristic testing device for a centrifugal pendulum damper and a testing method based on non-contact measurement. Background Technology

[0002] Vibration and noise in automotive transmission systems are significant factors affecting overall vehicle performance. They not only reduce ride comfort but also exacerbate fatigue wear on transmission system components, shortening their lifespan. With the development of internal combustion engines towards smaller displacements and turbocharging, the torsional vibrations (especially second-order vibrations) generated by the engine crankshaft rotation are becoming increasingly prominent, placing higher demands on transmission system vibration damping technology.

[0003] Centrifugal pendulum vibration absorber (CPVA) is a type of tuned dynamic vibration absorber. It utilizes a mass block suspended around a rotational axis, driven by centrifugal force, to oscillate along a preset trajectory during rotation, generating a counter-torque to counteract torsional vibrations in the transmission system. This technology has expanded from early applications in reciprocating internal combustion engines in aviation to modern automotive transmission systems. During the research, optimization, and performance verification phases of CPVA, accurately obtaining the actual motion trajectory and relative motion parameters of the pendulum block and rollers under high-speed rotation is crucial for evaluating its vibration damping performance.

[0004] However, existing measurement techniques for the internal motion characteristics of CPVA still have limitations and cannot meet the testing requirements of high-performance vibration dampers. Conventional contact measurements (such as bonded strain gauges or accelerometers) increase the attached mass of the pendulum blocks, making the leads prone to detachment under high-speed centrifugal force, and can disrupt the dynamic balance of the CPVA itself, making it difficult to guarantee test accuracy and causing interference to moving parts. On the other hand, while simulation analysis can provide theoretical reference, it is difficult to accurately reproduce the dynamic characteristics when dealing with complex physical conditions such as lubricant splashing and thermomechanical coupling deformation inside the vibration damper.

[0005] In recent years, non-contact methods such as laser Doppler vibration measurement technology have been introduced into the field of precision measurement. However, when conducting actual tests on CPVA, existing non-contact optical measurement solutions face many challenges because the internal components are in a state of combined motion with the flywheel's revolution and their own oscillation, and are usually enclosed within a structural shell: First, due to limitations in the observation window and high-speed rotation, the optical signals acquired by the sensors are usually discontinuous and have blind spots; second, oil mist splashed in the sealed environment can easily cause optical path interference; and third, it is difficult to accurately calculate the relative vibration angular velocity between the pendulum and the roller directly from the composite motion linear velocity acquired by the sensor.

[0006] Therefore, there is a need in the field for a device and detection method that can overcome the limitations of closed rotating structures and optical interference under simulated actual excitation conditions, and realize online, real-time, high-precision and interference-free measurement of the internal moving parts of CPVA.

[0007] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this invention, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that the present invention does not possess the features of these prior art. On the contrary, the present invention already possesses all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a non-contact measurement method integrating a laser Doppler vibration meter, aiming to achieve comprehensive detection of the relative motion state of the CPVA pendulum block and roller.

[0009] This invention provides a vibration testing device for a centrifugal pendulum damper, used to test the dynamic characteristics of the centrifugal pendulum damper under test, comprising: A servo motor is connected to the primary flywheel of the centrifugal pendulum damper under test to simulate the power input and torsional vibration excitation of an engine. The hysteresis brake is connected to the secondary flywheel of the centrifugal pendulum damper under test and is used to apply load torque to the centrifugal pendulum damper under test. The primary flywheel of the centrifugal pendulum damper under test has an observation window sealed by a transparent plate, and the surfaces of the centrifugal pendulum blocks and rollers inside it are respectively equipped with reflective markings. The laser Doppler vibration meter is fixed to the outside of the primary flywheel. When the observation window rotates with the primary flywheel to the position of the laser Doppler vibration meter's optical path, the optical path passes through the observation window and illuminates the reflective mark. The power control unit is connected to the servo motor, hysteresis brake and laser Doppler vibration meter respectively. It is used to control the test conditions, synchronously collect data and acquire the system key phase signal. Based on the key phase signal and the order tracking algorithm, the discontinuous linear velocity signal caused by the rotation of the observation window is reconstructed into a continuous signal to evaluate the dynamic characteristics of the centrifugal pendulum vibration damper under test.

[0010] According to a preferred embodiment, the testing device of the present invention further includes: an input shaft torque and speed sensor disposed on the output shaft of the servo motor, and an output shaft torque and speed sensor disposed on the input shaft of the hysteresis brake; both the input shaft torque and speed sensor and the output shaft torque and speed sensor are communicatively connected to the power controller to provide key phase signals and speed and torque feedback.

[0011] According to a preferred embodiment, the side of the transparent plate facing the inside of the shock absorber is coated with an anti-fouling coating; the transparent plate is statically sealed to the primary flywheel by fasteners, silicone sealant, and elastic sealing gaskets sandwiched between the contact surfaces.

[0012] According to a preferred embodiment, the power controller has a built-in torsional vibration waveform generation module for outputting dynamic speed control commands containing specific-order fluctuations to the servo motor. ,in The target average speed, This represents the amplitude of the rotational speed fluctuation. To incentivize the order, The mean angular velocity.

[0013] According to a preferred embodiment, the reflective markings include reflective markings on the centrifugal pendulum block and reflective markings on the roller, which are respectively disposed on the non-contact surfaces of the centrifugal pendulum block and the roller, and are both reflective media.

[0014] A second aspect of the present invention provides a vibration testing method for a centrifugal pendulum damper, comprising the following steps: Step 1, Test conditions and excitation settings: The power control unit controls the servo motor to drive the centrifugal pendulum damper under test to rotate and superimpose torsional vibration excitation, while controlling the hysteresis brake to apply the set load torque; Step 2, Multi-parameter synchronous acquisition and signal reconstruction: The laser Doppler vibration meter acquires the linear velocity signal of the reflective marker; for the discontinuous linear velocity signal caused by the rotation of the observation window, the power control unit combines the key phase signal and uses the resampling and envelope fitting algorithm based on order tracking to reconstruct the discontinuous signal into a continuous signal, and eliminates the influence of the flywheel revolution through coordinate system transformation, and calculates the vibration angular velocity of the centrifugal pendulum block and the roller; Step 3, Data Processing and Characteristic Analysis: The power control unit filters the calculated vibration angular velocity, calculates the relative motion parameters between the centrifugal pendulum block and the roller, as well as the vibration isolation rate of the damper, and comprehensively evaluates the dynamic characteristics of the tested centrifugal pendulum damper.

[0015] According to a preferred embodiment, the specific method for coordinate system transformation in step 2 is as follows: Establish a fixed coordinate system O-XYZ for the laser Doppler vibration meter and a rotating coordinate system O-xyz that rotates synchronously with the primary flywheel, where the Z-axis is parallel to the flywheel rotation axis and is the laser incident direction; Let the real-time rotation angle of the flywheel be... The measured linear velocity of the reflective marker along the laser incident direction is: The radial distance from the reflective marker to the center of the flywheel's rotation is R, and the distance to the center of the oscillation is L; The angular velocity of the centrifugal pendulum block can be calculated iteratively using the following formula. : ; The angular velocity of the roller vibration is solved using the same coordinate system transformation algorithm.

[0016] According to a preferred embodiment, step 2, the resampling and envelope fitting algorithm based on order tracking specifically includes: The system uses the key phase signal as the trigger and phase reference, and maps the transient data points collected in each rotation cycle to the angular position in that cycle according to the timestamp, and extracts the points with the same phase to form a discrete signal; For missing data segments caused by optical blind spots, a cubic spline interpolation algorithm based on envelope fitting is used for interpolation filling. By using an equal-angle incremental resampling algorithm, discrete signals are converted into equally spaced signals in the time domain. Combined with the known angular velocity-time relationship, the signals are mapped back to the time domain to reconstruct continuous vibration angular velocity signals.

[0017] According to a preferred embodiment, the specific process of filtering the calculated vibration angular velocity in step 3 is as follows: Wavelet filtering algorithm is used to process the vibration angular velocity to remove noise components that do not include the damping frequency; The acquired speed and torque signals are filtered using a moving average filtering algorithm.

[0018] According to a preferred embodiment, the specific process for calculating the relative motion parameters and the vibration isolation rate of the damper in step 3 is as follows: The vibration angular velocity after filtering is integrated and differentiated to obtain the vibration angular displacement and vibration angular acceleration. The relative angular displacement, relative angular velocity and relative angular acceleration between the centrifugal pendulum block and the roller are quantified by the difference calculation. The Savitzky-Golay algorithm is used to extract the angular velocity trend term corresponding to the rotational speed signal and decompose it to obtain the angular velocity amplitude. The RMS value of the torsional vibration of the powertrain was obtained. The vibration isolation rate of the damper is calculated according to the following formula: ; in, This indicates the amplitude of the angular velocity at the input end of the centrifugal pendulum damper. This indicates the amplitude of the angular velocity at the output end of the centrifugal pendulum damper.

[0019] The present invention has the following advantages: 1. Non-contact measurement without interference: The use of laser Doppler vibration measurement technology in conjunction with reflective markings avoids interference from contact measurement on the movement trajectory of the centrifugal pendulum and roller. Combined with the dynamic sealing design of the acrylic transparent window, it ensures the stability of the optical path and does not affect the normal operation of the CPVA. The measurement process causes no wear to the measured component. 2. Precise capture of relative motion parameters: By synchronously acquiring the angular displacement signals of the centrifugal pendulum block and the roller, comprehensive quantification of relative angular displacement, relative angular velocity, and relative angular acceleration is achieved; 3. Simplified and easy to implement: No complex optical imaging system is required. Relying on sensors, the experimental environment requirements are reduced, and it can be directly applied to production line testing and after-sales maintenance scenarios. Attached Figure Description

[0020] Figure 1 A perspective view of a testing apparatus according to a preferred embodiment of the present invention; Figure 2 A front view of a testing apparatus according to a preferred embodiment of the present invention; Figure 3 A front view of a centrifugal pendulum damper according to a preferred embodiment of the present invention; Figure 4 An internal view of a centrifugal pendulum damper according to a preferred embodiment of the present invention.

[0021] List of reference numerals 1: Stand; 2: Movable base plate; 3: Servo motor; 4: First support; 5: Laser Doppler vibration meter support; 6: Laser Doppler vibration meter; 7: Input shaft torque and speed sensor; 8: Primary flywheel connecting flange; 9: Centrifugal pendulum vibration damper; 10: Secondary flywheel connecting flange; 11: Output shaft torque and speed sensor; 12: Second support; 13: Hysteresis brake; 14: Power controller; 15: Primary flywheel; 16: Transparent plate; 17: Bolt; 18: Centrifugal pendulum block; 19: Roller; 20: Reflective markings on centrifugal pendulum block; 21: Reflective markings on roller. Detailed Implementation

[0022] The following is a detailed explanation with reference to the accompanying drawings.

[0023] Figure 1 and Figure 2In the embodiment shown, a sliding groove is provided on the left half of the platform 1. The movable base plate 2 is set along the sliding groove to facilitate installation. The base of the servo motor 3 and the first bracket 4 are fixedly mounted on the movable base plate 2 by bolts 17. The first bracket 4 is located at the output shaft end of the servo motor 3. The base of the second bracket 12 and the hysteresis brake 13 are fixedly mounted on the right half of the platform 1 by bolts 17. The second bracket 12 is located at the input shaft end of the hysteresis brake 13. By adjusting the position of the movable base plate 2, the relative position and connection form of the testing equipment and the tested vibration damper are ensured to be reasonable.

[0024] The output shaft of the servo motor 3 is fixedly connected to the primary flywheel 15 of the damper under test through the primary flywheel connecting flange 8, thereby realizing the connection between the output shaft of the servo motor and the primary flywheel side of the damper under test. The servo motor 3 is used to simulate the power input and order torsional vibration excitation of the crankshaft end of the engine. An input shaft torque and speed sensor 7 is set on the output shaft of the servo motor 3, and the input torque and speed are obtained by the input shaft torque and speed sensor 7.

[0025] The laser Doppler vibration meter 6 detects the centrifugal pendulum damper 9, obtains relevant data, and transmits it to the power control unit 14 for data processing via a transmission line.

[0026] The hysteresis brake 13 has an output shaft torque and speed sensor 11 installed on its brake shaft. The output shaft torque and speed sensor 11 detects and obtains the speed torque, which can apply dynamic alternating load torque for braking output torque.

[0027] The centrifugal pendulum vibration damper 9 has its input shaft fixedly connected to the primary flywheel 15 of the vibration damper under test via the primary flywheel connecting flange 8, and its output shaft fixedly connected to the secondary flywheel of the vibration damper under test via the secondary flywheel connecting flange 10. An input shaft torque and speed sensor 7 is installed on the input shaft to detect and obtain the input torque and speed.

[0028] The power control unit 14 is used to set different working scenarios for the vibration damper under test, process the data detection signals of each sensor, and evaluate the characteristics of the vibration damper under test based on the data processing results.

[0029] The centrifugal pendulum vibration test device of this embodiment is suitable for dynamic characteristic testing of various automotive centrifugal pendulum vibration dampers (CPVA). It can synchronously collect and analyze the relative motion parameters of the centrifugal pendulum block 18 and the roller 19, as well as the input and output torque and speed of the damper. The test method is based on this device, achieving fully automated control and data processing, with high measurement accuracy and convenient operation. Figure 3 and Figure 4 The centrifugal pendulum vibration test device and test method of this embodiment are operated according to the following steps: I. Assembly and Pretreatment of the Testing Equipment (a) Overall assembly of the device 1. Basic support arrangement: Fix the test stand 1 on the horizontal test bench, ensuring that the horizontality error of the bottom surface of the test stand is ≤0.05mm / m. The movable base plate 2 is slidably connected to the guide rail of the test stand 1. The installation spacing can be adjusted according to the specifications of the centrifugal pendulum vibration damper 9 to adapt to the testing requirements of vibration dampers of different sizes.

[0030] 2. Power and Braking End Installation: The servo motor 3 is fixed to the movable base plate 2 via the first bracket 4. The output shaft of the servo motor 3 is rigidly connected to one end of the input shaft torque and speed sensor 7. The other end of the input shaft torque and speed sensor 7 is coaxially fixed to the primary flywheel 15 of the centrifugal pendulum damper 9 under test via the primary flywheel connecting flange 8. Anti-loosening adhesive is applied to the mating surface of the connecting flange to ensure that there is no gap in the transmission. The hysteresis brake 13 is fixed to the other side of the stand 1 via the second bracket 12. Its input shaft is rigidly connected to one end of the output shaft torque and speed sensor 11. The other end of the output shaft torque and speed sensor 11 is coaxially fixed to the secondary flywheel of the centrifugal pendulum damper 9 via the secondary flywheel connecting flange 10. The coaxiality error of the entire transmission chain is ≤0.02mm to avoid additional vibration interference during the rotation process.

[0031] 3. Vibration Measurement Unit Installation: The laser Doppler vibration meter 6 is fixed to the outside of the primary flywheel 15 of the centrifugal pendulum damper 9 via the laser Doppler vibration meter bracket 5. The spatial position of the bracket is adjusted so that the optical path of the laser Doppler vibration meter 6 passes perpendicularly through the transparent plate 16 on the primary flywheel 15. When the observation window rotates at high speed with the primary flywheel 15 through the optical path, the laser spot sequentially or separately illuminates the reflective markings 20 on the pendulum block and 21 on the roller, ensuring stable reflected light signals. The laser Doppler vibration meter 6 and its bracket 5 are fixed to the lower movable base plate 2. Its optical emission center is vertically lower than the center line of the main shaft, allowing the horizontally emitted optical path of the laser Doppler vibration meter 6 to pass unobstructed directly below the input shaft torque and speed sensor 7 and the flange 8, thus establishing a periodically aligned optical relationship with the observation port of the lower half of the primary flywheel 15 of the centrifugal pendulum damper 9.

[0032] 4. Control and data processing unit connection: The power control unit 14 establishes a two-way communication connection with the servo motor 3, hysteresis brake 13, input shaft torque and speed sensor 7, output shaft torque and speed sensor 11 and laser Doppler vibration meter 6 via industrial Ethernet. After connecting to a 220V industrial power supply, the communication status of each device is debugged to ensure that there is no packet loss in signal transmission and that the timestamp synchronization deviation is ≤1ms.

[0033] (II) Pretreatment of the centrifugal pendulum damper under test 1. Opening and sealing of observation window: A fan-shaped or partially arc-shaped observation window is opened in the non-stressed area of ​​the primary flywheel 15 of the centrifugal pendulum damper 9. Compared with the test bench based on the principle of surface scattering of the measured shaft disclosed in CN108303261A, this application solves the defect of the prior art that it cannot penetrate the fully enclosed shell to measure the motion state of the internal vibration damping components by opening an observation window with light transmission properties on the primary flywheel 15, and realizes online monitoring of the vibration absorption elements inside the centrifugal pendulum damper. The primary flywheel 15 has a circular body, an observation window opened in the non-stress area of ​​the body, and a transparent plate that seals the window. The window is covered by a transparent plate 16 made of transparent material (such as acrylic). The transparent plate and the primary flywheel 15 establish a static seal relationship through an elastic sealing gasket set between the contact surfaces, so that the transparent plate can maintain the integrity of the internal lubrication environment of the primary flywheel 15 even when subjected to centrifugal force. At the same time, the side of the transparent plate facing the inside of the damper is coated with an anti-fouling coating (such as an oleophobic coating) with oil droplet guiding ability, so that the oil mist splashed inside is deflected from the center of the optical path under the action of centrifugal force, ensuring the penetration of the laser signal. The transparent plate 16 has high light transmittance as well as good mechanical strength and rigidity. The contact surface between the transparent plate 16 and the primary flywheel 15 is covered with an elastic sealing gasket. The sealing connection is achieved by using high and low temperature resistant and oil-resistant silicone sealant and fasteners (such as bolts 17, or alternative connection methods such as snap-fit ​​connection and structural adhesive bonding). It ensures no leakage and no loosening within the working temperature range of 0-120℃. Moreover, the light transmittance of the transparent plate 16 is ≥92%, which does not affect the transmission of laser light path.

[0034] 2. Reflective Marking Application: High-reflectivity reflective media (such as reflective film or high-reflectivity coating) are applied to the flat, non-contact surfaces of the centrifugal pendulum block 18 and the roller 19 to form centrifugal pendulum block reflective marking 20 and roller reflective marking 21. The reflectivity of the reflective film or coating is ≥95%. The application or coating location avoids the moving contact area between the centrifugal pendulum block 18 and the roller 19. Strong double-sided adhesive or surface curing treatment is used for fixation to ensure that it does not fall off during rotation.

[0035] 3. Initial Zero-Position Calibration and Parameter Import: Before system startup, the initial zero-position calibration is completed by manual static rotation combined with the Z-phase zero-point pulse of the key phase sensor, that is, determining the initial rotation angle of the primary flywheel 15 of the centrifugal pendulum damper 9 at the zero point of time (t=0). and the initial angular displacement of the centrifugal pendulum block 18 All of these are preset known values ​​(e.g., defined as 0°) and used as the starting boundary conditions for subsequent iterative calculations; at the same time, the known structural parameters in the design drawings are imported into the power control machine 14, namely the radial distance R from the point where the reflective mark 20 of the centrifugal pendulum block is located to the center of rotation of the flywheel, and the distance L to the center of the swing.

[0036] II. Specific Steps for Vibration Testing of Centrifugal Pendulum Vibration Damper The testing method in this embodiment is based on the testing device assembled and debugged as described above. It follows three core steps: test condition setting → multi-parameter synchronous acquisition → data processing and relative motion analysis. The entire process is automated by the power control unit 14. The specific operation is as follows: Step 1: Test Condition Settings 1. Input the test target parameters in the operation interface of the power control unit 14. The target speed range is 500-3000r / min, the load type and load torque range is 0-50Nm, and set the engine order torsional vibration excitation parameters. The settings can be customized according to the actual application conditions of the vibration damper under test. 2. The power controller 14 sends a start command to the servo motor 3, which drives the centrifugal pendulum damper 9 under test to rotate via closed-loop frequency conversion control; the power controller 14 has a built-in torsional vibration waveform generation module, which can output speed control commands. ,in The target average speed, This represents the amplitude of the rotational speed fluctuation. To incentivize the order, To achieve the average angular velocity, the power controller 14 sends a dynamic speed control command with high-frequency order fluctuations to the servo motor 3. The servo motor 3 tracks the dynamic command through closed-loop vector control to reproduce the order torsional vibration of the engine crankshaft until the input speed detected by the input shaft torque speed sensor 7 stabilizes at the target speed. 3. The power controller 14 synchronously sends a load command to the hysteresis brake 13. Based on the torque obtained by the output shaft torque and speed sensor 11, the power controller 14 precisely controls the hysteresis brake 13 to apply the set load torque, thereby completing energy absorption. 4. After the speed of the servo motor 3 and the load torque of the hysteresis brake 13 both reach the set value and run stably for 30 seconds, the power control unit 14 automatically triggers the data acquisition command and enters the multi-parameter synchronous acquisition stage.

[0037] Step 2: Multi-parameter synchronous acquisition 1. After receiving the acquisition command, the laser Doppler vibration meter 6 synchronously acquires the vibration velocity signals of the centrifugal pendulum block reflective mark 20 and the roller reflective mark 21 at a sampling frequency of 1kHz. During the acquisition process, the system uses the key phase signal of the input shaft as the trigger and phase reference, and synchronously acquires the signals through phase triggering and linkage with the key phase signal. The power control unit 14 calculates the acquired linear velocity signal into the actual vibration angular velocity in real time through the following coordinate system transformation algorithm: Establish the fixed coordinate system O-XYZ of the laser vibration meter and the rotating coordinate system O-xyz that rotates synchronously with the primary flywheel 15, where the Z-axis is the laser incident direction and is parallel to the rotation axis of the primary flywheel 15, the Z-axis coincides with the rotation axis of the flywheel, and the X-axis points radially to the swing center of the centrifugal pendulum block 18 along the flywheel; let the real-time rotation angle of the flywheel be... ,in The real-time angular velocity of the flywheel is synchronously acquired by the input shaft torque and speed sensor; the angular displacement of the centrifugal pendulum block 18 relative to the flywheel is... The radial distance from the reflective mark 20 of the centrifugal pendulum block to the center of rotation of the flywheel is R, and the distance to the center of the swing is L. These are known structural parameters of the vibration damper under test.

[0038] The linear velocity of the reflective marker point along the laser incident direction, directly measured by the laser vibrometer, is: The radial distance from the reflective marker 20 of the centrifugal pendulum block to the center of rotation of the flywheel is R, and the distance to the center of the oscillation is L. The Z-coordinate of the reflective marker point in the fixed coordinate system is... Taking its derivative yields Through the formula: The angular velocity of the centrifugal pendulum block 18 was calculated iteratively. To eliminate the influence of the flywheel's revolution motion; the vibration angular velocity of roller 19 is solved using the same coordinate system transformation algorithm; and the electrical signal is transmitted in real time to the high-speed data acquisition module of the power control unit 14; in the specific iteration process, the system adopts a computational numerical solution method, which calculates the previous sampling time ( The updated angular displacement of the centrifugal pendulum block 18 has been determined. Substituting into the right side of the calculation formula, and combining it with the measured linear velocity at the current time (t)... The angular velocity of the centrifugal pendulum block 18 at the current moment is calculated. Then, the angular displacement value of the centrifugal pendulum block 18 at the current moment is updated by numerical integration. This allows for iterative solution; 2. The input shaft torque and speed sensor 7 and the output shaft torque and speed sensor 11 maintain a synchronized sampling frequency with the laser Doppler vibration meter 6, synchronously acquiring the rotational speed at the input end of the vibration damper. Torque Torque and output speed Torque The timestamp synchronization deviation of all acquired signals is ≤1ms; 3. The power controller 14 stores all the collected data in real time using comma-separated values ​​(CSV) format, which facilitates subsequent data analysis, export and reproduction. During the acquisition process, the power controller 14 monitors the signal quality in real time. If abnormalities such as excessive signal noise, packet loss or sensor disconnection occur, it will immediately issue an alarm and pause the acquisition. It will restart after the fault is diagnosed.

[0039] To address the signal discontinuity problem caused by optical blind spots, the power controller 14 executes a resampling and envelope fitting algorithm based on order tracking to reconstruct the discontinuous signal into a continuous signal. Regarding the centrifugal pendulum experimental setup mentioned in CN110274765A, which failed to solve the signal distortion problem caused by rotational obstruction, this application establishes a signal processing chain through the power controller, used to calculate the transformation of discontinuous signals into continuous dynamic characteristics: a key phase sensor, used to capture the angular reference zero point of the primary flywheel 15; a laser measurement module, used to extract the linear velocity of the reflective marker during the observation window's conduction period; and a reconstruction algorithm module, used to perform interpolation compensation during optical blind spots. In this process, when the observation window rotates with the primary flywheel 15 to the conducting phase of the vibration meter's optical path, the laser measurement module, guided by triggering conditions, synchronizes with the key phase signal to obtain transient linear velocities with clear phase meanings. When the primary flywheel 15 rotates to the blind zone phase where the housing blocks the optical path, the reconstruction algorithm module, constrained by known angular velocity trends, utilizes a cubic spline interpolation algorithm based on envelope fitting and predictions from historical data points. With the phase achieved after full-cycle data stitching, the power control unit performs differential calculations between the measured linear velocity signal and the flywheel's revolution angular velocity according to the coordinate system transformation formula, thereby calculating the true vibration velocity of the centrifugal pendulum block 18 after excluding the revolution background. This reconstruction algorithm module includes a timestamp mapping unit, an angle domain sampling unit, and an interpolation filling unit. The timestamp mapping unit and the angle domain sampling unit can establish a mapping relationship when the key phase signal is in a stable pulse state, normalizing discrete transient data points to specific angular positions within the same rotation cycle. This ensures the integrity of the reconstructed signal and avoids high-frequency harmonic interference caused by window discontinuities. The system uses the key phase signal of the input shaft as the trigger and phase reference, mapping the transient data points acquired by the laser in each rotation cycle to a precise angular position within that cycle based on their acquisition timestamps. Data points acquired at the same angular position in multiple consecutive rotation cycles are extracted. These "in-phase points" are arranged in chronological order, forming a discrete signal describing the change of that point with rotational speed. This process essentially achieves equivalent angular domain sampling of the vibration signal of the rotating component, compensating for the observation blind spot within a single cycle through multi-cycle data stitching. For missing data segments caused by optical blind spots, a cubic spline interpolation algorithm based on envelope fitting is used for smooth filling, i.e., using the fitted signal amplitude envelope as a constraint condition to ensure that the interpolated waveform still conforms to the physical trend even when the missing segment is long; then, an equal-angle incremental resampling algorithm is used to convert the above discrete signal, which is uniform in the angular domain but non-uniform in the time domain, into a completely uniform signal in the time domain. Finally, combined with the known angular velocity-time relationship (… This allows the angular domain signal to be remapped back to the time domain, thereby reconstructing the angular velocity of the centrifugal pendulum block 18, which is formally continuous and complete. The vibration angular velocity of roller 19 Signal.

[0040] Step 3: Data Processing and Relative Motion Analysis The power control unit 14 automatically preprocesses, calculates parameters, and analyzes relative motion characteristics of the acquired, stored, and reconstructed continuous raw data. It calculates the relative motion parameters between the centrifugal pendulum block 18 and the roller 19, and simultaneously analyzes the torsional vibration data at the input and output ends to calculate the vibration isolation rate of the damper, comprehensively evaluating the dynamic characteristics of the tested centrifugal pendulum damper 9. Specifically, this process is divided into three sub-steps, all calculations are completed in the data analysis module of the power control unit 14, and the results are displayed in real time in the form of curves and numerical reports. (1) Signal preprocessing The angular velocity of the reconstructed pendulum block was calculated. and roller vibration angular velocity A wavelet filtering algorithm based on the db4 wavelet basis is used for denoising. In the downstream stage of data processing, the wavelet filtering algorithm built into the power control unit performs denoising on the calculated vibration angular velocity. Preferably, the db4 wavelet basis and a 5-level decomposition structure are used to form a multi-scale analysis relationship with the original vibration signal. This allows noise components not containing the damping frequency to be stripped in the wavelet domain, ensuring that the final output vibration isolation rate evaluation index of the damper meets the expected peak signal-to-noise ratio. The db4 wavelet is chosen because its tight support is suitable for analyzing mechanical transient characteristics; the 5-level decomposition, at a sampling rate of 1kHz, can effectively separate the low-frequency true signal containing the target order vibration and damping frequency from the high-frequency detail signal of hundreds of Hz containing oil mist scattering and electrical noise. After removing the high-frequency noise, the reconstructed signal can, for example, ensure a peak signal-to-noise ratio ≥22dB after processing. The input and output speed and torque signals are smoothed using a moving average filtering algorithm. Preferably, the window size of the moving average filtering algorithm is set to 50ms to filter instantaneous fluctuations. This window size can cover the peaks of the entire speed range to smooth noise without causing distortion of low-frequency torsional vibration. The processed speed fluctuation amplitude is ≤0.5% and the torque fluctuation amplitude is ≤0.8%. The filtered signal completely retains the trend and characteristics of the original signal without distortion.

[0041] (2) Calculation of motion parameters of a single component The angular velocity of the pre-treated pendulum block and roller vibration angular velocity Perform definite integral operations, with the integration interval being the acquisition time domain and the initial integration value set to 0, to obtain the vibration angular displacement of the centrifugal pendulum block 18. Vibration angular displacement of roller 19 ; The angular velocities of the pre-processed pendulum block and roller were subjected to first-order central difference calculations with a difference step size of 1 ms to obtain the angular acceleration of the centrifugal pendulum block 18. Angular acceleration of the roller 19 During the calculation process, outliers that exceed the reasonable range are automatically removed to ensure parameter accuracy.

[0042] (3) Solving for relative motion parameters Based on the single-component motion parameters calculated above, the power control unit 14 quantifies the relative motion state between the centrifugal pendulum block 18 and the roller 19 through difference calculation. The specific calculation is as follows: The relative angular displacement between the centrifugal pendulum block 18 and the roller 19 is obtained by calculating the difference. : (1); Relative angular velocity : (2); Relative angular acceleration: (3); This allows us to quantify the relative motion state of the two.

[0043] (4) Vibration reduction effect data analysis The rotational speeds at the input and output ends of the centrifugal pendulum damper are collected by the input shaft torque and speed sensor 7 and the output shaft torque and speed sensor 11. and Based on the relationship between rotational speed and angular velocity: (4); In the formula, This indicates the rotational speed obtained from the speed and torque sensor. It represents angular velocity.

[0044] The Savitzky-Golay algorithm is used to obtain the measured angular velocity through least squares fitting and filtering smoothing. Trend items This effectively preserves the shape and feature points of the measured signal. The rotational speed obtained through testing on the test bench... Then, the angular velocity is obtained through equation (4). By performing trend decomposition, the amplitude of angular velocity can be obtained. .

[0045] Then, the root mean square (RMS) value of the torsional vibration of the powertrain is obtained: (6); In the formula, For speed amplitude, The number of signals.

[0046] Next, define the vibration isolation ratio. as follows: (7); in, This indicates the angular velocity amplitude at the primary flywheel 15 end of the centrifugal pendulum damper 9. This represents the amplitude of the angular velocity of the secondary flywheel of the centrifugal pendulum damper.

[0047] The power control unit 14 automatically calculates the above relative motion parameters, as well as the root mean square value and vibration isolation rate of the powertrain, and comprehensively analyzes the characteristics of the tested centrifugal pendulum damper 9 under the corresponding working conditions.

[0048] III. Implementation Effects of Testing Apparatus and Methods The test device in this embodiment has a small structural modification, requiring only a simple observation window to be opened on the primary flywheel 15 of the centrifugal pendulum damper 9 under test. The dynamic sealing design of the acrylic transparent plate does not affect the normal operation of the damper. Furthermore, the non-contact measurement method of the laser Doppler vibration meter avoids interference with the motion trajectory of the centrifugal pendulum block 18 and roller 19 by contact measurement, resulting in no wear and no additional load. The test method has a high sampling frequency, good data synchronization, and a timestamp deviation of ≤1ms. The combination algorithm of wavelet filtering and moving average filtering effectively removes noise, accurately captures the relative motion parameters of the centrifugal pendulum block 18 and roller 19, and can evaluate the vibration reduction performance of the centrifugal pendulum damper.

[0049] It should be noted that the specific embodiments described above are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this invention, and these solutions all fall within the scope of this invention and its protection. Those skilled in the art should understand that this specification and its accompanying drawings are illustrative and not intended to limit the scope of the claims. The scope of protection of this invention is defined by the claims and their equivalents. This specification contains multiple inventive concepts; terms such as "preferredly," "according to a preferred embodiment," or "optionally" indicate that the corresponding paragraph discloses an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept.

Claims

1. A vibration testing device for a centrifugal pendulum damper, used to test the dynamic characteristics of the centrifugal pendulum damper under test, characterized in that, include: The servo motor (3) is connected to the primary flywheel (15) of the centrifugal pendulum damper (9) under test, and is used to simulate the power input and torsional vibration excitation of the engine. The hysteresis brake (13) is connected to the secondary flywheel of the centrifugal pendulum damper (9) under test, and is used to apply load torque to the centrifugal pendulum damper (9) under test. The primary flywheel (15) of the centrifugal pendulum damper (9) under test has an observation window sealed by a transparent plate (16), and the surfaces of the centrifugal pendulum block (18) and roller (19) inside it are respectively provided with reflective markings. The laser Doppler vibration meter (6) is fixed on the outside of the primary flywheel (15). When the observation window rotates with the primary flywheel (15) to the position of the optical path of the laser Doppler vibration meter (6), the optical path passes through the observation window and illuminates the reflective mark. The power control unit (14) is connected to the servo motor (3), hysteresis brake (13) and laser Doppler vibration meter (6) respectively. It is used to control the test conditions, synchronously collect data and obtain the system key phase signal, and reconstruct the discontinuous linear velocity signal caused by the rotation of the observation window into a continuous signal based on the key phase signal and the order tracking algorithm, so as to evaluate the dynamic characteristics of the centrifugal pendulum damper (9) under test.

2. The vibration testing device for a centrifugal pendulum damper according to claim 1, characterized in that, Also includes: An input shaft torque and speed sensor (7) is installed on the output shaft of the servo motor (3), and an output shaft torque and speed sensor (11) is installed on the input shaft of the hysteresis brake (13). The input shaft torque and speed sensor (7) and the output shaft torque and speed sensor (11) are both connected to the power controller (14) for providing the key phase signal and speed and torque feedback.

3. The vibration testing device for a centrifugal pendulum damper according to claim 1, characterized in that, The transparent plate (16) is coated with an anti-fouling coating on the side facing the inside of the centrifugal pendulum damper (9); the transparent plate (16) is statically sealed to the primary flywheel (15) by fasteners, silicone sealant and elastic sealing gaskets sandwiched between the contact surfaces.

4. The vibration testing device for a centrifugal pendulum damper according to claim 1, characterized in that, The power control unit (14) has a built-in torsional vibration waveform generation module, which is used to output dynamic speed control commands containing specific order fluctuations to the servo motor (3). ,in The target average speed, This represents the amplitude of the rotational speed fluctuation. To incentivize the order, The mean angular velocity.

5. The vibration testing device for a centrifugal pendulum damper according to claim 1, characterized in that, The reflective markings include a centrifugal pendulum block reflective marking (20) and a roller reflective marking (21), which are respectively set on the non-contact surfaces of the centrifugal pendulum block (18) and the roller (19), and are both reflective media.

6. A vibration testing method for a centrifugal pendulum damper, implemented based on the centrifugal pendulum damper vibration testing device according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1, test conditions and excitation settings: The power controller (14) controls the servo motor (3) to drive the centrifugal pendulum damper (9) under test to rotate and superimpose torsional vibration excitation, while controlling the hysteresis brake (13) to apply the set load torque; Step 2, Multi-parameter synchronous acquisition and signal reconstruction: The laser Doppler vibrometer (6) acquires the linear velocity signal of the reflective mark; In response to the discontinuity of the linear velocity signal caused by the rotation of the observation window, the power controller (14) combines the key phase signal and uses the resampling and envelope fitting algorithm based on order tracking to reconstruct the discontinuous signal into a continuous signal. It also eliminates the influence of the flywheel revolution through coordinate system transformation and calculates the vibration angular velocity of the centrifugal pendulum block (18) and the roller (19). Step 3, data processing and characteristic analysis: The power control unit (14) filters the calculated vibration angular velocity, calculates the relative motion parameters of the centrifugal pendulum block (18) and the roller (19) and the vibration isolation rate of the damper, and comprehensively evaluates the dynamic characteristics of the centrifugal pendulum damper (9) under test.

7. The vibration testing method for a centrifugal pendulum damper according to claim 6, characterized in that, In step 2, the specific method for coordinate system transformation is as follows: Establish a fixed coordinate system O-XYZ for the laser Doppler vibration meter (6) and a rotating coordinate system O-xyz that rotates synchronously with the primary flywheel (15), wherein the Z-axis is parallel to the flywheel rotation axis and is the laser incident direction; Let the real-time rotation angle of the flywheel be... The measured linear velocity of the reflective marker along the laser incident direction is: The radial distance from the reflective marker to the center of the flywheel's rotation is R, and the distance to the center of the oscillation is L; The angular velocity of the centrifugal pendulum block (18) is calculated iteratively using the following formula. : ； The vibration angular velocity of the roller (19) is solved using the same coordinate system transformation algorithm.

8. The vibration testing method for a centrifugal pendulum damper according to claim 6, characterized in that, In step 2, the resampling and envelope fitting algorithm based on order tracking specifically includes: The system uses the key phase signal as the trigger and phase reference, maps the transient data points collected in each rotation cycle to the angular position in that cycle according to the timestamp, and extracts the points with the same phase to form a discrete signal; For missing data segments caused by optical blind spots, a cubic spline interpolation algorithm based on envelope fitting is used for interpolation filling. By using an equal-angle incremental resampling algorithm, discrete signals are converted into equally spaced signals in the time domain. Combined with the known angular velocity-time relationship, the signals are mapped back to the time domain to reconstruct continuous vibration angular velocity signals.

9. The vibration testing method for a centrifugal pendulum damper according to claim 6, characterized in that, The specific process of filtering the calculated vibration angular velocity in step 3 is as follows: The vibration angular velocity is processed using a wavelet filtering algorithm to remove noise components that do not include the damping frequency; The acquired speed and torque signals are filtered using a moving average filtering algorithm.

10. The vibration testing method for a centrifugal pendulum damper according to claim 6, characterized in that, The specific process for calculating the relative motion parameters and the vibration isolation rate of the damper in step 3 is as follows: The vibration angular velocity after filtering is integrated and differentiated to obtain the vibration angular displacement and vibration angular acceleration. The relative angular displacement, relative angular velocity and relative angular acceleration of the centrifugal pendulum block (18) and the roller (19) are quantified by the difference calculation. The Savitzky-Golay algorithm is used to extract the angular velocity trend term corresponding to the rotational speed signal and decompose it to obtain the angular velocity amplitude. The RMS value of the torsional vibration of the powertrain was obtained. The vibration isolation rate of the damper is calculated according to the following formula: ； in, This indicates the amplitude of the angular velocity at the input end of the centrifugal pendulum damper. This indicates the amplitude of the angular velocity at the output end of the centrifugal pendulum damper.

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