A curve howling control method based on dithering force injection

Abstract

The present invention discloses a curve whistling control method based on dithering force injection, which relates to the field of rail transit vibration isolation technology. The method includes the following steps: S1, determining the curve whistling frequency by on-site testing method or simulation analysis method; S2, determining the dithering force application method according to the actual conditions on site, including application on the wheels and application on the rails; S3, determining the characteristics of the dithering force, including frequency, amplitude and waveform; S4, determining the layout of the dithering device, including the layout spacing and layout position of the dithering device; S5, selecting the dithering force application device according to the on-site conditions; S6, selecting a suitable installation method for installation based on the selected dithering force application device. The curve whistling control method based on dithering force injection proposed by the present invention does not require major changes to the original track and wheel structure, is simple to implement, and the equipment for applying the dithering force is relatively conventional. Compared with traditional whistling suppression methods, it is more stable and controllable, and has lower cost.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit vibration isolation, and in particular to a curve whistling control method based on dithering force injection. Background Art

[0002] When urban rail transit trains negotiate tight curves, high wheel-rail creep often causes a piercing noise known as "curve squeal." This noise, originating from self-excited vibrations between the wheels and rails, is characterized by a high pitch and high sound pressure level. This noise not only causes auditory discomfort but can also negatively impact the health of train operators and nearby residents.

[0003] To alleviate this problem, the industry has explored a variety of noise reduction strategies. In terms of track maintenance, the application of lubricants or friction modifiers is intended to reduce the friction coefficient, thereby reducing the creep force between the wheel and rail. However, although lubricants can effectively reduce friction, they may also lead to a decrease in traction performance; and although friction modifiers can adjust the friction characteristics, they are not enough to deal with the squeal problem caused by modal coupling. Another method is to implement damping measures on the wheels, such as using annular damping wheels or elastic wheels. These technologies suppress the vibration amplitude by increasing the damping effect of the wheels, thereby reducing the squeal. Despite this, the effectiveness of such solutions in actual applications is mixed, and there is a lack of a stable and reliable method to continuously and effectively control squeal.

[0004] In recent years, research has proposed a new approach based on dithering force control, theoretically exploring how to utilize specific forces to suppress curve squeal. However, further research is needed on the design principles and implementation paths for specific dithering forces. In summary, further exploration and development of more efficient and stable solutions are needed to completely resolve the curve squeal problem in urban rail transit. Summary of the Invention

[0005] The purpose of the present invention is to propose a curve howling control method based on shaking force injection, which adopts specific shaking force parameters and arrangement methods. By applying shaking force, the lateral vibration speed of the wheel is rapidly reduced. When the shaking force meets certain conditions, the howling phenomenon can be effectively eliminated.

[0006] To achieve the above objectives, the present invention proposes a curve howling control method based on dithering force injection, the specific steps of which are as follows:

[0007] Step S1, determining the curve whistling frequency by field testing or simulation analysis;

[0008] Step S2: determining the shaking force application method according to the actual conditions on site;

[0009] Step S3: determining the characteristics of the jitter force, including frequency, amplitude, and waveform;

[0010] Step S4: Determine the arrangement of the shaking devices, including the arrangement spacing and arrangement positions of the shaking devices;

[0011] Step S5: selecting a shaking force applying device;

[0012] Step S6: Install the shaking force applying device.

[0013] Preferably, in step S1, the field test method is to perform spectrum analysis based on vibration or noise results measured on site to determine the howling frequency.

[0014] Preferably, in step S1, the simulation analysis method is to establish a finite element model according to the vehicle profile, track parameters and friction coefficient, and determine the howling frequency through transient dynamics analysis or complex eigenvalue analysis.

[0015] Preferably, in step S2, the shaking force is applied by wheels and rails; wherein the shaking force is applied by rails in two ways:

[0016] Step S21: relying on the reaction force support device, one end of the shaking device is fixed to the reaction force device, and the other end contacts the rail head;

[0017] Step S22: The shaking device is directly fixed to the rail waist.

[0018] Preferably, in step S3, the axial modal frequencies of each pitch diameter of the wheel are obtained according to the results of the wheel modal analysis, and then the optimal frequency is determined according to the sensitivity of the wheel vibration insertion loss to the jitter force at different frequencies; the wheel vibration velocity insertion loss at different amplitudes is calculated and analyzed to determine the jitter force amplitude corresponding to the maximum insertion loss; the suppression effect of the three waveforms, square wave, sine wave and triangle wave, is calculated, and the optimal waveform is determined.

[0019] Preferably, in step S4, the arrangement position includes above the fastener and in the middle of the span.

[0020] Preferably, in step S5, a shaking force applying device is selected according to on-site conditions, and the shaking force applying device is a motor or a piezoelectric actuator.

[0021] Preferably, in step S6, when the motor is used as the shaking force applying device, the motor is fixed to the track bed by installing bolts; when the piezoelectric actuator is used as the shaking force applying device, the reaction force support device is installed by drilling holes on the track bed and the piezoelectric actuator is installed, or the piezoelectric actuator is directly fixed to the rail waist.

[0022] Therefore, the present invention proposes a curve howling control method based on jitter force injection, which has the following beneficial effects:

[0023] (1) The present invention proposes a curve whistling control method based on shaking force injection, which adopts specific shaking force parameters and arrangement methods. After the shaking force is applied, the lateral vibration speed of the wheel is rapidly reduced. When the shaking force meets certain conditions, the whistling phenomenon can be effectively eliminated.

[0024] (2) The present invention proposes a curve whistling control method based on dithering force injection, which does not require major changes to the original track and wheel structure and is easy to implement. The device for applying dithering force is relatively conventional, which is more stable and controllable than traditional whistling suppression methods and has lower cost.

[0025] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flowchart of the overall implementation of a curve howling control method based on jitter force injection according to the present invention;

[0027] Figure 2 This is a schematic diagram of frequency domain results of a curve howling control method based on jitter force injection according to the present invention;

[0028] Figure 3 Schematic diagram of equivalent damping ratio of a curve howling control method based on jitter force injection according to the present invention;

[0029] Figure 4 A schematic diagram of a method for applying a dithering force to a wheel in a curve squeal control method based on dithering force injection according to the present invention;

[0030] Figure 5 Schematic diagram of a rail vibration force application method for a curve squeal control method based on vibration force injection according to the present invention;

[0031] Figure 6 A schematic diagram of a method for applying dithering force to an A-type rail in a curve squeal control method based on dithering force injection according to the present invention;

[0032] Figure 7 A schematic diagram of a method for applying dithering force to a B-type rail in a curve squeal control method based on dithering force injection according to the present invention;

[0033] Figure 8 Schematic diagram of wheel axial modes and frequencies of a curve squeal control method based on jitter force injection according to the present invention;

[0034] Figure 9 A schematic diagram of wheel speed insertion loss under different frequencies and amplitudes of dithering forces in a curve squeal control method based on dithering force injection according to the present invention;

[0035] Figure 10Schematic diagram of insertion loss of different waveforms of a curve howling control method based on jitter force injection according to the present invention;

[0036] Figure 11 A schematic diagram of wheel speeds at different positions where dithering forces are applied in a curve squeal control method based on dithering force injection according to the present invention;

[0037] Figure 12 A schematic diagram of wheel speed change after applying a shaking force in a curve squeal control method based on shaking force injection according to the present invention;

[0038] Figure 13 Schematic diagram of rail displacement caused by jitter force in a curve squeal control method based on jitter force injection according to the present invention. DETAILED DESCRIPTION

[0039] To make the technical solutions, advantages, and purposes of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are part of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0041] like Figure 1 As shown, the present invention provides a curve howling control method based on jitter force injection, and the specific steps are as follows:

[0042] Step S1: Determine the howling frequency.

[0043] There are two ways to determine the howling frequency, as follows:

[0044] S11. On-site testing method: determine the howling frequency by performing spectrum analysis on the vibration or noise results measured on site. Figure 2 As shown, the results of wheel speed at frequency are given, and the whine frequency is determined to be 1017 Hz.

[0045] S12, simulation analysis method, according to the vehicle profile, track parameters and friction coefficient, establish a finite element model, and determine the howling frequency through transient dynamic analysis or complex eigenvalue analysis. Figure 3 As shown in the figure, the complex eigenvalue analysis results corresponding to a certain type of wheel. The three frequencies in the figure have negative values, which means that howling may occur at these three frequencies.

[0046] Step S2: Determine the shaking force application method according to the actual conditions on site.

[0047] like Figure 4 and Figure 5 As shown, the shaking force can be applied on the wheels or on the rails, which can be determined according to the actual situation on site. In this application, the method of applying the force on the rails is selected from the perspective of easy installation.

[0048] There are two ways to apply shaking force on the rails, such as Figure 6 As shown in FIG, a shaking force is applied to the A-type rail, which requires a reaction force support device. One end of the shaking device is fixed to the reaction force device, and the other end contacts the rail head. Figure 7 As shown, the shaking force is applied to the B-type rail, and the shaking device is directly fixed to the rail waist.

[0049] Step S3: Determine the characteristics of the jitter force, including frequency, amplitude, and waveform.

[0050] First, based on the results of wheel modal analysis, the axial modal frequencies of each wheel pitch diameter are obtained. The optimal frequency is then determined based on the sensitivity of the wheel vibration insertion loss to jitter forces at different frequencies. Furthermore, the wheel vibration velocity insertion loss at different amplitudes is calculated and analyzed to determine the jitter force amplitude corresponding to the maximum insertion loss. For three common waveforms—square, sine, and triangular—the suppression effects of each waveform are calculated, and the optimal waveform is determined.

[0051] like Figure 8 As shown in the figure, several axial modes that will not cause howling are given. The vibration frequencies are preset to these natural frequencies, and the wheel speed insertion loss at different vibration amplitudes at these frequencies is calculated. The calculation formula is as follows:

[0052]

[0053] like Figure 9 As shown in the figure, the load required for selecting a frequency of 2711Hz is smaller, and the optimal load is 6000N. After determining the frequency and amplitude, as shown in the figure, Figure 10 As shown in the figure, the insertion loss of different waveforms is given. It can be seen that the square wave has the best effect, so the square wave is selected.

[0054] Step S4: Determine the arrangement of the shaking device.

[0055] The layout method mainly includes the layout spacing and layout position of the dither device. The insertion loss of different layout spacings is shown in Table 1.

[0056] Table 1 Insertion loss of different arrangement spacing

[0057] spacing One span Second span Three spans Four spans Five spans Six spans Insertion loss -75 -55 -37 -20 -2 0

[0058] According to the results in the table, the layout spacing should not exceed 4 spans, otherwise the howling suppression effect will be poor.

[0059] There are two ways to arrange the position, one is above the fastener and the other is in the middle of the span. Figure 11 As shown in the figure, the simulation results of the wheel speed when the arrangement spacing is 5 spans are given. It is obvious that it is more advantageous to arrange it above the fastener.

[0060] Step S5, device selection. This application provides two ways to apply shaking force, including motors and piezoelectric actuators, which can be selected according to the on-site environment.

[0061] Step S6: Device Installation. Because the damping effect is very sensitive to load, it is crucial to secure the vibration device properly. Based on the device selected in step S5, if a motor is used, it can be secured to the track bed with mounting bolts. If a piezoelectric actuator is used, a reaction force support device can be drilled in the track bed and then the piezoelectric actuator can be installed, or the piezoelectric actuator can be directly secured to the rail waist.

[0062] like Figure 12 As shown in the figure, once the dithering force is applied, the lateral vibration velocity decreases rapidly. Ideally, the lateral vibration velocity of the wheel will eventually approach zero, indicating that the curve squeal phenomenon has disappeared. Furthermore, even if the dithering force design is not optimized, curve squeal may not be completely eliminated, but the wheel vibration can still be suppressed to a certain extent.

[0063] At the same time, the shaking device will cause the rail to move laterally. Figure 13 As shown in the figure, the lateral displacement of the rail caused by different amplitudes of shaking force (frequency 2711Hz) is given, and its maximum value does not exceed 0.006mm, which can be considered to have no impact on safety.

[0064] Therefore, the present invention provides a curve howling control method based on dithering force injection, which adopts specific dithering force parameters and arrangement methods. After applying dithering force, the lateral vibration speed of the wheel is rapidly reduced. When the dithering force meets certain conditions, the howling phenomenon can be effectively eliminated. At the same time, there is no need to make major changes to the original track and wheel structure. The implementation method is simple, and the device for applying dithering force is relatively conventional. Compared with traditional howling suppression methods, it is more stable and controllable, and has lower cost.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A curve howling control method based on jitter force injection, characterized in that: The specific steps are as follows: Step S1, determining the curve whistling frequency by field testing or simulation analysis; The field test method is to perform spectrum analysis based on the vibration or noise results measured on site to determine the howling frequency; The simulation analysis method is to establish a finite element model based on the vehicle profile, track parameters and friction coefficient, and determine the squeal frequency through transient dynamic analysis or complex eigenvalue analysis; Step S2: determining the shaking force application method according to the actual conditions on site; The shaking force is applied by wheels and rails; wherein the shaking force is applied by rails in a manner that the shaking device is directly fixed to the rail waist; Step S3: determining the characteristics of the jitter force, including frequency, amplitude, and waveform; Step S4: Determine the arrangement of the shaking devices, including the arrangement spacing and arrangement positions of the shaking devices; the arrangement spacing does not exceed 4 spans, and the arrangement positions include above the fasteners and in the middle of the span; Step S5: selecting a shaking force applying device; Step S6: installing the shaking force applying device; In step S3, the axial modal frequencies of each wheel pitch diameter are obtained based on the wheel modal analysis results. The optimal frequency is then determined based on the sensitivity of the wheel vibration insertion loss to the jitter force at different frequencies. The wheel vibration velocity insertion loss at different amplitudes is calculated and analyzed to determine the jitter force amplitude corresponding to the maximum insertion loss. The suppression effect of the square wave, sine wave, and triangle wave waveforms is calculated to determine the optimal waveform. In step S5, a shaking force applying device is selected according to the on-site conditions, and the shaking force applying device is a piezoelectric actuator.

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