Method and device for determining acceleration filter frequency band of EMU frame

Abstract

The present invention discloses a method and device for determining an EMU frame acceleration filter band, wherein the method comprises: solving the frequencies corresponding to each low-order mode of the EMU bogie frame based on the EMU bogie frame low-order modal dynamics differential equation; collecting the vertical acceleration and lateral acceleration of the bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determining the main energy distribution frequency bands of the vertical acceleration signal and the main energy distribution frequency bands of the lateral acceleration signal of the bogie frame; and determining the EMU frame acceleration filter band based on the frequencies corresponding to each low-order mode of the EMU bogie frame and the main energy distribution frequency bands of the vertical acceleration signal and the main energy distribution frequency bands of the lateral acceleration signal of the EMU bogie frame. The present invention can reasonably and effectively determine the EMU frame acceleration filter band, providing reliable theoretical and data support for the subsequent use of frame acceleration to diagnose track mid-wave irregularities.

Description

Technical Field

[0001] The present invention relates to the technical field of high-speed railway maintenance engineering, and in particular to a method and device for determining an acceleration filter frequency band of an EMU frame. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. No statement herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] With the continuous advancement of China's high-speed rail technology in recent years, the operating speeds of in-service EMUs have further increased, reaching 350 km / h on some lines. This has placed even higher demands on EMU safety and ride comfort. The track system, as a key component of the track-vehicle coupling system, plays a crucial role in this regard: during EMU operation, track irregularities often act as an excitation source, affecting the EMU's operating state. Therefore, track irregularities are closely related to the EMU's vibration state. However, current management of track irregularities is primarily based on the "High-Speed ​​Railway Ballastless Track Maintenance Rules," which stipulate the use of peak and average management methods to manage track quality. However, in actual operation, there have been instances of uncomfortable rides, such as low-frequency periodic train sway, despite the track geometry amplitude remaining within limits. This is a typical example of poor wheel-rail matching parameters caused by poor track profile, which in turn leads to poor EMU operating posture. Therefore, using vehicle dynamic response to evaluate track service condition has become a new development trend and research hotspot.

[0004] Wheelsets, bogies, and car bodies are the three major components subject to forced vibration in EMUs. Under the influence of damping elements such as primary and secondary suspension springs, they exhibit different vibration characteristics. Wheelset vibration can reflect the high-frequency vibration state of the wheel-rail contact plane. Acceleration at the wheelset axlebox is often collected to approximate wheelset acceleration, and a relatively mature axlebox acceleration-based method for assessing short-wave track irregularities has been established. Car body acceleration signals, on the other hand, have a lower frequency, concentrated in the 0-10 Hz range, allowing for inversion of long-wave track irregularities. Furthermore, they are more easily correlated with passenger ride experience, leading to the use of car body acceleration to assess the lateral stability of vehicle systems. As a key vibrating component, current research on the bogie's vibration characteristics primarily focuses on fatigue strength, specifically estimating the bogie's safe operating life under actual operating conditions. However, research on low-frequency vibration characteristics, which reflect track input characteristics, is limited, and existing research is insufficiently comprehensive and cannot yet guide engineering applications.

[0005] As a complex, large and highly nonlinear mechanical vibration system, the EMU system's components will produce two responses during the vibration process. One part is the "follow-up" response caused by external excitation. This part of the response is mainly affected by the external excitation source and has a low frequency. Especially in the bogie and car body positions, there may be resonance between the external excitation input and the car body's own low-order modes. This part of the vibration can better reflect the external excitation properties; the other part is the local high-frequency elastic vibration caused by the influence of its own structure. This part of the vibration is closely related to the safe service life of the bogie.

[0006] Effectively extracting the low-frequency vibration signals of the frame that reflect the characteristics of track excitation is a scientific prerequisite for using frame acceleration to evaluate track mid-wave irregularities. Therefore, it is necessary and urgent to find a frame acceleration filter band selection method that can be used to analyze the low-frequency vibration characteristics of the frame. Summary of the Invention

[0007] An embodiment of the present invention provides a method for determining an EMU frame acceleration filter frequency band, for reasonably and effectively determining an EMU frame acceleration filter frequency band. The method includes:

[0008] The frequencies corresponding to the various low-order modes of the EMU bogie frame are solved based on the pre-established low-order modal dynamic differential equations of the EMU bogie frame in the longitudinal and horizontal planes; the low-order modal dynamic differential equations are established by taking into account the primary elastic suspension device on the wheelset and the secondary elastic suspension device on the bogie;

[0009] Collecting the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determining the main distribution frequency bands of the energy of the vertical acceleration signal and the main distribution frequency bands of the energy of the lateral acceleration signal of the EMU bogie frame;

[0010] The acceleration filtering frequency band of the EMU frame is determined according to the frequencies corresponding to the low-order modes of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame.

[0011] The embodiment of the present invention further provides a device for determining the acceleration filter frequency band of an EMU frame, for reasonably and effectively determining the acceleration filter frequency band of an EMU frame, the device comprising:

[0012] A low-order modal frequency determination unit is used to solve the frequencies corresponding to each low-order mode of the EMU bogie frame based on the low-order modal dynamics differential equations of the EMU bogie frame pre-established in the longitudinal and horizontal planes; the low-order modal dynamics differential equations are equations established by taking into account the primary elastic suspension device on the wheelset and the secondary elastic suspension device on the bogie;

[0013] The measured acceleration analysis unit is used to collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determine the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame;

[0014] The filter frequency band determination unit is used to determine the EMU frame acceleration filter frequency band according to the frequencies corresponding to each low-order mode of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame.

[0015] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0016] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0017] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0018] In an embodiment of the present invention, a scheme for determining the acceleration filter frequency band of an EMU frame is provided by: solving the frequencies corresponding to the various low-order modes of the EMU bogie frame according to the low-order modal dynamics differential equations of the EMU bogie frame pre-established in the longitudinal and horizontal planes; the low-order modal dynamics differential equations are equations established by taking into account the first elastic suspension device on the wheelset and the second elastic suspension device on the bogie; collecting the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed; , determine the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame; according to the frequencies corresponding to each low-order mode of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame, determine the EMU frame acceleration filtering band, which can reasonably and effectively determine the EMU frame acceleration filtering band, and provide reliable theoretical and data support for the subsequent use of frame acceleration to diagnose the wave irregularity of the track. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 This is a scene picture of the track plate warping in an embodiment of the present invention;

[0021] Figure 2 This is the original waveform diagram of the vertical acceleration of the frame in an embodiment of the present invention;

[0022] Figure 3 This is a waveform diagram of the vertical acceleration of the frame after filtering in an embodiment of the present invention;

[0023] Figure 4 Graph showing the root mean square value of vertical acceleration of the frame after filtering in an embodiment of the present invention;

[0024] Figure 5 This is a simplified vertical model diagram of an EMU in an embodiment of the present invention;

[0025] Figure 6a It is a horizontal plane projection diagram of a simplified transverse model diagram of an EMU in an embodiment of the present invention;

[0026] Figure 6b It is a longitudinal vertical plane projection diagram of the simplified transverse model diagram of the EMU in the embodiment of the present invention;

[0027] Figure 7 This is a diagram showing the results of the vertical acceleration power spectrum analysis of each section frame in an embodiment of the present invention;

[0028] Figure 8 This is a diagram showing the power spectrum analysis results of the lateral acceleration of each section frame in an embodiment of the present invention;

[0029] Figure 9 Schematic diagram of the flow of a method for determining an acceleration filter frequency band of an EMU frame according to an embodiment of the present invention;

[0030] Figure 10 Schematic diagram of the structure of the EMU frame acceleration filter frequency band determination device in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0032] The inventors discovered a technical problem: EMU bogies, as a unique mechanical structure, not only experience vertical and lateral displacement during motion, but also undergo localized high-frequency elastic deformation due to their inherent structural characteristics. This causes currently collected bogie accelerations to contain significant localized high-frequency vibration components, interfering with analysis of the bogie's low-frequency vibration characteristics. Consequently, direct data analysis to assess current track conditions is impossible.

[0033] Taking the above-mentioned technical problems into consideration, the inventors have proposed a scheme for determining the acceleration filter band of an EMU frame. This scheme is a scheme for selecting the acceleration filter band of an EMU frame for analyzing the low-frequency vibration characteristics of the frame and diagnosing track irregularities. The scheme clarifies the specific range of "low frequency" in the low-frequency vibration of the frame and the specific data characteristics of the measured frame acceleration signal, thereby determining a reasonable and effective filter band to effectively remove the portion that reflects the low-frequency vibration characteristics of the frame from the original signal. Utilizing the content of this scheme, we can better understand the low-frequency vibration characteristics of the frame during EMU operation and improve the scientificity and rationality of the subsequent use of the dynamic response of the frame to evaluate the service status of the track. This scheme clarifies the "low frequency" range in the low-frequency vibration characteristics of the frame and scientifically and effectively determines the corresponding frequencies of the low-order modes of the bogie frame. The following is a detailed introduction to the scheme for determining the acceleration filter band of an EMU frame.

[0034] Figure 9 FIG. 1 is a flow chart of a method for determining an acceleration filter frequency band of an EMU frame according to an embodiment of the present invention. Figure 9 As shown, the method includes the following steps:

[0035] Step 101: solving the frequencies corresponding to the various low-order modes of the EMU bogie frame based on pre-established low-order modal dynamic differential equations of the EMU bogie frame in the longitudinal and horizontal planes; the low-order modal dynamic differential equations are equations established taking into account the primary elastic suspension device on the wheelset and the secondary elastic suspension device on the bogie;

[0036] Step 102: collecting vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determining the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame;

[0037] Step 103: Determine the EMU frame acceleration filtering frequency band according to the frequencies corresponding to the low-order modes of the EMU bogie frame, and the main energy distribution frequency bands of the vertical acceleration signal and the lateral acceleration signal of the EMU bogie frame.

[0038] The method for determining the acceleration filter frequency band of the EMU frame provided by the embodiment of the present invention, when working: according to the low-order modal dynamics differential equations of the EMU bogie frame pre-established in the longitudinal vertical plane and the horizontal plane, the frequencies corresponding to the various low-order modes of the EMU bogie frame are solved; the low-order modal dynamics differential equations are equations established by considering the first elastic suspension device on the wheelset and the second elastic suspension device on the bogie; the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed are collected. The main energy distribution frequency bands of the vertical acceleration signal and the lateral acceleration signal of the EMU bogie frame are determined based on the frequencies corresponding to the various low-order modes of the EMU bogie frame, as well as the main energy distribution frequency bands of the vertical acceleration signal and the lateral acceleration signal of the EMU bogie frame. This method can reasonably and effectively determine the EMU frame acceleration filter band, providing reliable theoretical and data support for the subsequent use of frame acceleration to diagnose track mid-wave irregularities. The following is a detailed introduction to the EMU frame acceleration filter band determination method.

[0039] This embodiment of the present invention establishes a differential equation of motion for an EMU to derive a range of modal distributions that can reflect the EMU's rigid body. Combined with the actual collected frame acceleration signals, this method provides a filter band selection method for analyzing the low-frequency vibration characteristics of the EMU frame. Low-frequency vibration refers to the servoing motion of the frame as a rigid body under external excitation. The concept of low-frequency vibration is proposed to distinguish it from localized high-frequency elastic vibration. Analysis results indicate that the low-frequency vibration band generally corresponds to below 30Hz to 40Hz. The specific frequency varies depending on the EMU model, with some models falling below 30Hz and others below 40Hz. The method specifically includes selecting the filter band range and implementing the filtering of the frame acceleration signal. The goal is to increase the proportion of signals reflecting the current frame low-frequency vibration state in the measured signal, improve the accuracy of the frame low-frequency vibration analysis, and provide theoretical and data support for the subsequent diagnosis of track irregularities using frame acceleration. This is described in detail below.

[0040] This embodiment of the present invention studies the vertical and lateral accelerations of the EMU bogie frame, collected by acceleration sensors installed at the ends of the bogie frame. The filter band selection method for analyzing the low-frequency characteristics of the bogie frame consists of three main parts: the first part is to solve the vehicle system's natural modal frequencies based on vehicle system dynamics and free vibration theory; the second part is to analyze the measured bogie acceleration characteristics on a typical line; and the third part is to determine and implement the filter band.

[0041] Part 1: Solving the natural modal frequencies of the vehicle system based on vehicle system dynamics and free vibration theory, i.e., step 101 above.

[0042] At present, most EMUs in my country adopt a two-system suspension device. Therefore, the dynamic differential equation established in the embodiment of the present invention takes into account both the primary and secondary elastic suspension devices.

[0043] Since the low-order modes of motion of the bogie frame are manifested as frame heave, frame nod, frame yaw (lateral movement) and frame head shake, the embodiment of the present invention establishes motion equations in the longitudinal and horizontal planes respectively.

[0044] (1) Vertical plane

[0045] The 10-degree-of-freedom equation of the two-system suspension system is established. Therefore, the position of the system is determined by 10 generalized coordinates, namely the vertical displacement z of the vehicle body c and Nodding Corner Vertical displacement z of the front bogie frame b1 and Nodding Corner Vertical displacement z of the rear bogie frame b2 and Nodding Corner Vertical displacement z of the four wheelsets w1 、z w2 、z w3 、z w4 The simplified vertical model of the EMU is as follows: Figure 5 shown.

[0046] (a) Frame vibration:

[0047]

[0048] (b) Frame nodding vibration:

[0049]

[0050] Where J cy ——y-axis of the vehicle body passing through its center of mass c The moment of inertia of the shaft;

[0051] M c - vehicle body mass;

[0052] J by ——the y-axis of the bogie frame passing through its center of mass b The moment of inertia of the shaft;

[0053] M b — bogie frame quality;

[0054] C sz —Vertical damping of the secondary suspension on the bogie;

[0055] K sz —Vertical stiffness of the secondary suspension on the bogie;

[0056] C pz - vertical damping of the primary suspension on the wheelset;

[0057] K pz —vertical stiffness of the primary suspension on the wheelset;

[0058] l - half of the center distance between the two bogies (vehicle fixed distance);

[0059] l1——half of the bogie wheelbase.

[0060] (2) Horizontal plane

[0061] Considering only the lateral and yaw motions of each wheelset and the bogie frame, and ignoring the frame roll motion, the six-degree-of-freedom equations of the two-stage suspension system are established. Therefore, the system position is determined by six generalized coordinates: the bogie lateral displacement y b and the shaking angle ψ b ; lateral displacement of the front wheel pair y w1 and the shaking angle ψ w1 ; Lateral displacement y of rear wheel pair w2 and the shaking angle ψ w2 ; The simplified transverse model of the EMU is as follows Figure 6a and Figure 6b shown.

[0062] (c) Lateral vibration of the frame:

[0063]

[0064] (d) Frame shaking vibration:

[0065]

[0066] Where J bz - the z-axis of the bogie frame passing through its center of mass b The moment of inertia of the shaft;

[0067] M b — bogie frame quality;

[0068] K sx - longitudinal stiffness of the secondary suspension on the bogie;

[0069] K sy - lateral stiffness of the secondary suspension on the bogie;

[0070] C sx - longitudinal damping of the secondary suspension on the bogie;

[0071] C sy - lateral damping of the secondary suspension on the bogie;

[0072] K px - longitudinal stiffness of the primary suspension on the wheelset;

[0073] K py - lateral stiffness of the primary suspension on the wheelset;

[0074] C px - longitudinal damping of the primary suspension on the wheelset;

[0075] C py - lateral damping of the primary suspension on the wheelset;

[0076] b——half of the lateral distance between the two rolling circles of the wheelset;

[0077] b1——half of the lateral spacing of the primary suspension spring;

[0078] b2——half of the lateral spacing of the secondary suspension spring;

[0079] l1——half of the bogie wheelbase.

[0080] In theory, any mechanical system can be simplified into a mass-spring-damper vibration system, and railway vehicles are no exception. In this case, when external forces act, the system dynamics equation can be expressed as

[0081]

[0082] Where, M is the mass matrix of the vibration system;

[0083] C——damping matrix of vibration system;

[0084] K——vibration system stiffness matrix;

[0085] x——system response;

[0086] F——external incentives to the system;

[0087] The low-order modes of the structure are determined by the suspension parameters and are unaffected by external factors, representing inherent characteristics of the system. Therefore, in the derivation, the system is considered to be in a free vibration state. In this free vibration state, the external force is zero, i.e., F = 0. In actual engineering applications, EMUs are large and complex machines, and the structural damping of their components has little impact on the natural frequency and mode shape of the entire system. Therefore, the damping C is considered to be zero here. The system dynamics equation is then transformed into:

[0088]

[0089] The above equation is a second-order homogeneous linear equation with constant coefficients, and its solution can be expressed as

[0090] x=Asin(ωt+φ) (7)

[0091] Where, A is the free vibration amplitude;

[0092] ω——system natural frequency, in radians;

[0093] φ——phase angle.

[0094] Substituting formula (7) into formula (6) yields:

[0095] (K-ω 2 M)A=0 (8)

[0096] Where A is the amplitude matrix of the displacement of each point in the system.

[0097] In the undamped state, when the system is in free vibration, the amplitude of the displacement of each point in the system cannot be 0 at the same time. Therefore, in order for the above formula to be valid, only the determinant of the matrix in the brackets must be 0, that is,

[0098] |K-ω 2 M|=0 (9)

[0099] Solving the eigenvalue of formula (9), the result can be expressed as

[0100] {ω1,ω2,...,ω n}

[0101] With the help of formula (10)

[0102]

[0103] The natural frequencies of each order of the system in Hz can be obtained.

[0104] According to the vibration equations of the frame floating, nodding, lateral movement and shaking head, after rewriting the above equations into the style of formula (6), the corresponding frequencies of the bogie frame floating, nodding, lateral movement and shaking head modes can be obtained by combining formulas (7)(9)(10).

[0105] Calculation formula for the corresponding frequency of the frame suspension mode.

[0106] (1) Frequency of structure fluctuation:

[0107]

[0108] (2) Framework nodding frequency:

[0109]

[0110] (3) Frame yaw frequency:

[0111]

[0112] (4) Frame shaking frequency:

[0113]

[0114] The above four modes are the common low-order (suspension) modes of EMUs and their corresponding frequency solution formulas.

[0115] As shown in Table 1 below, the natural mode corresponding frequencies of CRH2 and CRH5 vehicles are calculated using the formula.

[0116] Table 1 Natural mode corresponding frequency / Hz

[0117] Modal CRH2 CRH5 Ups and downs 6.31 6.78 nod 9.31 8.55 Lateral movement 14.51 13.94 Shake your head 42.03 29.73

[0118] In existing technologies, the frame is prone to continuous, short-term, and unresolved snaking motion in the lateral direction. This is closely related to the bogie frame's lateral displacement modal frequency. Therefore, in many current standards, the frame's lateral displacement state is monitored by applying a 0.1-10 Hz bandpass filter to the frame's lateral acceleration to evaluate the vehicle system's motion stability during operation. Furthermore, according to the principle of mechanical system vibration, when the excitation source frequency is very close to the mechanical system's natural frequency, resonance will occur in the mechanical system. Therefore, when analyzing the low-frequency vibration characteristics of the frame, the vertical modes of floating and nodding should be considered, while the lateral modes should be focused on.

[0119] From the above, it can be seen that in one embodiment, the low-order modal dynamics differential equations of the EMU bogie frame may include: the EMU bogie frame floating and sinking modal vibration equation (the above formula (1)), the frame nodding modal vibration equation (the above formula (2)), the frame lateral displacement modal vibration equation (the above formula (3)) and the frame shaking modal vibration equation (the above formula (4));

[0120] The frequencies corresponding to the various low-order modes of the EMU bogie frame may include: the frequencies corresponding to the EMU bogie frame floating and sinking modes, the frequencies corresponding to the frame nodding modes, the frequencies corresponding to the frame lateral displacement modes, and the frequencies corresponding to the frame shaking modes.

[0121] Part 2: Analysis of measured acceleration characteristics of a typical line structure, i.e., step 102 above.

[0122] When establishing the vehicle system dynamics equation and combining it with the free vibration theory to derive the bogie suspension mode, the entire vehicle system is assumed to be in an undamped state. However, during actual operation, the vehicle system does have damping. Therefore, there is still a certain difference between the derived results and the actual bogie suspension modal frequency. It is necessary to combine the analysis results of the measured data to jointly determine the appropriate filtering frequency band.

[0123] As shown in Table 2 below, the elastic modal frequencies of a certain type of vehicle bogie are obtained by ANSYS simulation.

[0124] Table 2 Elastic modal frequencies of bogies obtained by simulation

[0125] Mode shape Frequency Hz Order Reverse torsion of the beams on both sides around the horizontal axis in the vertical direction 31.192 1st-order elasticity First-order bending of frame beams 51.204 2nd order elasticity Reverse shear of beams on both sides in the horizontal plane 64.677 3rd-order elasticity Reverse torsion of the beams on both sides around the horizontal axis 68.904 4th-order elasticity Same-direction shearing of beams on both sides in the horizontal plane 75.675 5th-order elasticity First-order bending of the beams on both sides in the vertical direction 83.185 6th-order elasticity

[0126] A random sampling method was used to select 7 straight sections for analysis when the EMU passed through a typical line (which could be a ballastless line with an EMU speed of 300 km / h). The specific information of the sections is shown in Table 3.

[0127] Table 3 Segment specific information

[0128]

[0129]

[0130] from Figure 7 The power spectrum analysis of the vertical acceleration of the bogie in each section shows that the energy of the vertical acceleration signal in each section is primarily concentrated in the 0-50 Hz range, consistent with existing literature analysis results. The vibration energy of the bogie at frequencies above 50 Hz is extremely low. Within the 0-50 Hz range, the signal energy is primarily concentrated in the 0-20 Hz range. Furthermore, the local peak around 30 Hz is associated with the first-order elastic mode of the bogie. This frequency is close to the first-order irregularity of the wheelset itself, indicating that the bogie's elastic vibration is not caused by track irregularities.

[0131] from Figure 8 The power spectrum analysis of the lateral acceleration of the frame in each section shows that the lateral acceleration energy of the frame in each section is distributed within the range of 0 to 100 Hz, with the energy primarily concentrated in three frequency bands: 1 to 13 Hz, 35 to 55 Hz, and 70 to 90 Hz. This result is consistent with existing literature analysis. The 35 to 55 Hz and 70 to 90 Hz frequency bands are associated with the high-order elastic modes of the frame (as shown in Table 2 above), primarily reflecting localized high-frequency elastic vibrations of the frame during EMU operation.

[0132] From the above, we can conclude that the energy of the vertical acceleration signal of the measured structure on a typical line is mainly distributed in the frequency band of 0-20 Hz; the energy of the lateral acceleration signal of the measured structure on a typical line is mainly distributed in the frequency bands of 1-13 Hz, 35-55 Hz, and 70-90 Hz. Among them, the 35-55 Hz and 70-90 Hz bands are strongly correlated with the elastic modes of the structure itself and belong to the category of high-frequency elastic vibration.

[0133] As can be seen from the above, in one embodiment, collecting the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a constant speed, and determining the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame may include:

[0134] Collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a constant speed;

[0135] According to the power spectrum analysis results of the vertical acceleration of the frame in each section, the main distribution frequency band of the vertical acceleration signal energy of the EMU bogie frame is determined;

[0136] According to the power spectrum analysis results of the lateral acceleration of the frame in each section, the main distribution frequency band of the lateral acceleration signal energy of the EMU bogie frame is determined.

[0137] Part 3: Determining and implementing the frame vibration acceleration filter frequency band, namely the above-mentioned step 103.

[0138] Combining the previously reported results of solving the bogie frame suspension modal natural frequencies using the Newton-Euler method to establish the vehicle system dynamics differential equations with the time-frequency domain analysis of the frame vibration acceleration collected on a typical test track, it is believed that the following aspects should be considered when selecting the frame vibration acceleration filter band:

[0139] (1) Contains low-order mode (suspension mode) frequencies that can easily cause vehicle system resonance;

[0140] (2) The selected frequency band can better reflect the input characteristics of track wave irregularities and the impact of track wave irregularities on the current frame motion state;

[0141] (3) The selected filter frequency band should adapt to the dynamic performance differences between different types of EMUs as much as possible.

[0142] Common track irregularities are categorized into three types based on wavelength: short-wave track irregularities (wavelengths under 1 meter), medium-wave track irregularities (wavelengths 1-30 meters), and long-wave track irregularities (30-150 meters). Currently, short-wave track irregularities are primarily identified using axlebox acceleration. Given that the high-frequency vibration components at the bogie are significantly reduced by the vibration filtering effect of the primary suspension springs, frame acceleration is more suitable for diagnosing medium-wave track defects.

[0143] For example, for high-speed trains operating at 250-300 km / h, the frequency range corresponding to the wavelength of medium-wave track irregularities is 2-80 Hz. However, common medium-wave track defects, such as track slab warping, have a relatively low frequency range, within 20 Hz.

[0144] The frequency band corresponding to the vehicle system's elastic modes, the measured frame acceleration energy distribution, the frequency band corresponding to the wavelength of track medium-wave irregularities, and the frequency distribution of common track medium-wave defects are considered, taking into account the differences in suspension parameters between different EMUs. To ensure the consistency of the current track service status using frame accelerations from different EMUs, it is recommended that when using frame acceleration to evaluate typical medium-wave track irregularities, the filter band for the frame vertical acceleration signal should be 0.1-25 Hz, and the filter band for the frame lateral acceleration signal should be 0.1-20 Hz.

[0145] The specific implementation of filtering adopts the joint method of Fourier transform and inverse Fourier transform. The specific process is as follows:

[0146] The frame acceleration signal is x i ,i=0,1,2,…,N-1, where N represents the number of sampling points. Perform discrete Fourier transform on the signal to obtain X(k) and the corresponding frequency f(k)

[0147]

[0148]

[0149] Where, F s ——Sampling frequency.

[0150] The lower limit frequency F of the filter band corresponding to the vertical and lateral acceleration of the frame l , upper limit frequency F h As shown in Table 4.

[0151] Table 4 Detailed parameters of filter frequency band Hz

[0152] <![CDATA[F l ]]> <![CDATA[F h ]]> Frame vertical acceleration 0.1 25 Frame lateral acceleration 0.1 20

[0153] According to the determined filtering range [F l ,F h ], determine the frequency f(k) in [F l ,F h Integers other than ]

[0154]

[0155] In the formula, [] is an integer.

[0156] Let the Fourier coefficient of the corresponding term be 0. Perform inverse Fourier transform according to the following formula to obtain the filtered frame acceleration signal

[0157]

[0158] From the above, it can be seen that determining the EMU frame acceleration filter band based on the corresponding frequencies of each low-order mode of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame can include determining the EMU frame acceleration filter band based on one or any combination of the following objectives:

[0159] Contains low-order modal frequencies that can easily cause vehicle system resonance;

[0160] Contains signal components corresponding to higher-order modal frequencies that are less than a preset ratio;

[0161] The selected filter frequency band reflects the input characteristics of the track wave irregularity and the impact of the track wave irregularity on the current frame motion state;

[0162] The selected filter frequency band is adapted to the dynamic performance differences between different types of EMUs.

[0163] As can be seen from the above, the EMU frame acceleration filter frequency bands determined in the embodiments of the present invention may include: a frame vertical filter frequency band range and a frame transverse filter frequency band range. Furthermore, in the embodiments of the present invention, low-order and high-order modes are distinguished by the minimum elastic modal frequency, which is generally distributed between 30 and 40 Hz, with the specific frequency depending on the vehicle model.

[0164] In addition, the inventors verified the beneficial technical effects of the embodiments of the present invention through experiments:

[0165] It is known that the track slab warping occurred in the section K438+180~K438+210 of the test line. The on-site situation is as follows: Figure 1 shown.

[0166] like Figure 2 The figure shows the raw waveform of the vertical acceleration of the frame, acquired through time sampling at a sampling frequency of 5000Hz. This waveform shows that within the frequency band of 0 to 2500Hz, the amplitude of the vertical acceleration of the frame is approximately ±2g. The figure shows that the raw waveform of the vertical acceleration of the frame in the section where track slab warping occurs does not differ significantly from that in other sections, and the vibration amplitude is distributed within the ±1g range, showing no obvious anomalies.

[0167] The vertical acceleration signal of the frame is filtered with a bandpass of 0.1 to 25 Hz, and the results are as follows: Figure 3 As shown. Figure 3 It can be seen that in the low frequency band, the vertical acceleration amplitude of the frame is less than 1g, which is quite different from the unfiltered state, indicating that the original signal contains a large amount of high-frequency vibration components. Figure 3It can be seen from the image that the vertical acceleration of the structure in the problem section has repeatedly experienced harmonic phenomena with amplitudes greater than 0.4g. No similar harmonic phenomena have occurred in other sections.

[0168] When the structure vibrates greatly, the acceleration signal will carry a lot of energy. At this time, the energy contained in the signal can be quantitatively described by calculating the mean square value. Figure 3 The signal shown is solved for its RMS value, and the result is as follows Figure 4 As shown in the figure, the RMS value corresponding to the problem section is larger than that of other sections, with an amplitude exceeding 0.4g. This shows that the filtered vertical acceleration of the frame can be matched to the existing problems of the track structure, and the filter frequency band selection is reasonable and effective.

[0169] The present invention also provides a device for determining the acceleration filter frequency band of an EMU frame, as described in the following embodiments. Because the principles underlying the problem solved by this device are similar to those of the method for determining the acceleration filter frequency band of an EMU frame, the implementation of this device can be found in the implementation of the method for determining the acceleration filter frequency band of an EMU frame, and any repetitions will not be repeated.

[0170] Figure 10 FIG. 1 is a schematic diagram of the structure of a device for determining an acceleration filter frequency band of an EMU frame according to an embodiment of the present invention. Figure 10 As shown, the device includes:

[0171] The low-order modal frequency determination unit 01 is used to solve the frequencies corresponding to the various low-order modes of the EMU bogie frame based on the low-order modal dynamics differential equations of the EMU bogie frame pre-established in the longitudinal and horizontal planes; the low-order modal dynamics differential equations are equations established by taking into account the primary elastic suspension device on the wheelset and the secondary elastic suspension device on the bogie;

[0172] The measured acceleration analysis unit 02 is used to collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determine the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame;

[0173] The filter frequency band determination unit 03 is used to determine the EMU frame acceleration filter frequency band according to the frequencies corresponding to the various low-order modes of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame.

[0174] In one embodiment, the EMU bogie frame low-order modal dynamics differential equations may include: EMU bogie frame floating and sinking modal vibration equations, frame nodding modal vibration equations, frame lateral displacement modal vibration equations, and frame head shaking modal vibration equations;

[0175] The frequencies corresponding to the various low-order modes of the EMU bogie frame may include: the frequencies corresponding to the EMU bogie frame floating and sinking modes, the frequencies corresponding to the frame nodding modes, the frequencies corresponding to the frame lateral displacement modes, and the frequencies corresponding to the frame shaking modes.

[0176] In one embodiment, the measured acceleration analysis unit may be specifically used to:

[0177] Collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a constant speed;

[0178] According to the power spectrum analysis results of the vertical acceleration of the frame in each section, the main distribution frequency band of the vertical acceleration signal energy of the EMU bogie frame is determined;

[0179] According to the power spectrum analysis results of the lateral acceleration of the frame in each section, the main distribution frequency band of the lateral acceleration signal energy of the EMU bogie frame is determined.

[0180] In one embodiment, the filtering frequency band determining unit may be specifically configured to determine the EMU frame acceleration filtering frequency band according to one or any combination of the following objectives:

[0181] Contains low-order modal frequencies that can easily cause vehicle system resonance;

[0182] The selected filter frequency band reflects the input characteristics of track medium wave irregularity and the impact of track medium wave irregularity on the current frame motion state;

[0183] The selected filter frequency band is adapted to the dynamic performance differences between different types of EMUs.

[0184] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0185] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0186] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0187] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for determining the acceleration filter frequency band of the EMU structure is implemented.

[0188] In an embodiment of the present invention, a scheme for determining the acceleration filter frequency band of an EMU frame is provided by: solving the frequencies corresponding to the various low-order modes of the EMU bogie frame according to the low-order modal dynamics differential equations of the EMU bogie frame pre-established in the longitudinal and horizontal planes; the low-order modal dynamics differential equations are equations established by taking into account the first elastic suspension device on the wheelset and the second elastic suspension device on the bogie; collecting the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed; , determine the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame; according to the frequencies corresponding to each low-order mode of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame, determine the EMU frame acceleration filtering band, which can reasonably and effectively determine the EMU frame acceleration filtering band, and provide reliable theoretical and data support for the subsequent use of frame acceleration to diagnose the wave irregularity of the track.

[0189] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0190] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0191] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0192] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0193] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining the acceleration filter frequency band of a train frame, characterized in that: include: The frequencies corresponding to the various low-order modes of the EMU bogie frame are solved based on the pre-established low-order modal dynamic differential equations of the EMU bogie frame in the longitudinal and horizontal planes; the low-order modal dynamic differential equations are established by taking into account the primary elastic suspension device on the wheelset and the secondary elastic suspension device on the bogie; Collecting the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determining the main distribution frequency bands of the energy of the vertical acceleration signal and the main distribution frequency bands of the energy of the lateral acceleration signal of the EMU bogie frame; The acceleration filtering frequency band of the EMU frame is determined according to the frequencies corresponding to the low-order modes of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame.

2. The method for determining the acceleration filter frequency band of a train frame according to claim 1, wherein: The low-order modal dynamics differential equations of the EMU bogie frame include: the EMU bogie frame floating and sinking modal vibration equation, the frame nodding modal vibration equation, the frame lateral displacement modal vibration equation and the frame shaking modal vibration equation; The frequencies corresponding to the various low-order modes of the EMU bogie frame include: the frequencies corresponding to the EMU bogie frame floating and sinking modes, the frequencies corresponding to the frame nodding modes, the frequencies corresponding to the frame lateral displacement modes, and the frequencies corresponding to the frame shaking modes.

3. The method for determining the acceleration filter frequency band of an EMU frame according to claim 1, wherein: The vertical acceleration and lateral acceleration of the EMU bogie frame are collected when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame are determined, including: Collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a constant speed; According to the power spectrum analysis results of the vertical acceleration of the frame in each section, the main distribution frequency band of the vertical acceleration signal energy of the EMU bogie frame is determined; According to the power spectrum analysis results of the lateral acceleration of the frame in each section, the main distribution frequency band of the lateral acceleration signal energy of the EMU bogie frame is determined.

4. The method for determining the acceleration filter frequency band of a train frame according to claim 1, wherein: The EMU frame acceleration filter band is determined based on the corresponding frequencies of each low-order mode of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame, including determining the EMU frame acceleration filter band based on one or any combination of the following objectives: Contains low-order modal frequencies that can easily cause vehicle system resonance; The selected filter frequency band reflects the input characteristics of track medium wave irregularity and the impact of track medium wave irregularity on the current frame motion state; The selected filter frequency band is adapted to the dynamic performance differences between different types of EMUs.

5. A device for determining the acceleration filter frequency band of a train frame, characterized in that: include: A low-order modal frequency determination unit is used to solve the frequencies corresponding to each low-order mode of the EMU bogie frame based on the low-order modal dynamics differential equations of the EMU bogie frame pre-established in the longitudinal and horizontal planes; the low-order modal dynamics differential equations are equations established by taking into account the primary elastic suspension device on the wheelset and the secondary elastic suspension device on the bogie; The measured acceleration analysis unit is used to collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a uniform speed, and determine the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame; The filter frequency band determination unit is used to determine the EMU frame acceleration filter frequency band according to the frequencies corresponding to each low-order mode of the EMU bogie frame, as well as the main distribution frequency bands of the vertical acceleration signal energy and the main distribution frequency bands of the lateral acceleration signal energy of the EMU bogie frame.

6. The device for determining the acceleration filter frequency band of a train frame according to claim 5, wherein: The measured acceleration analysis unit is specifically used for: Collect the vertical acceleration and lateral acceleration of the EMU bogie frame when the EMU passes through multiple straight sections of a preset typical line at a constant speed; According to the power spectrum analysis results of the vertical acceleration of the frame in each section, the main distribution frequency band of the vertical acceleration signal energy of the EMU bogie frame is determined; According to the power spectrum analysis results of the lateral acceleration of the frame in each section, the main distribution frequency band of the lateral acceleration signal energy of the EMU bogie frame is determined.

7. The device for determining the acceleration filter frequency band of a train frame according to claim 5, wherein: The filtering frequency band determining unit is specifically configured to determine the EMU frame acceleration filtering frequency band according to one or any combination of the following objectives: Contains low-order modal frequencies that can easily cause vehicle system resonance; The selected filter frequency band reflects the input characteristics of the track wave irregularity and the impact of the track wave irregularity on the current frame motion state; The selected filter frequency band is adapted to the dynamic performance differences between different types of EMUs.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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