Noise control method, suspension system and off-road vehicle

Abstract

The application discloses a noise control method, a suspension system and an off-road vehicle, and relates to the technical field of vehicle noise control, wherein the suspension system comprises a suspension structure, two hydraulic cylinders and two sound pressure sensors; the suspension structure has two cross beams extending in the horizontal direction and being spaced apart in the vertical direction, and two vertical columns extending in the vertical direction and being spaced apart in the horizontal direction, and the vertical columns are connected to the end portions of the same side of the two cross beams respectively; one end of the two hydraulic cylinders is connected to the same cross beam, and the other end is connected to the two vertical columns respectively; the two sound pressure sensors are arranged at the front and rear positions of the vehicle respectively; the noise control method comprises the following steps: when it is determined that the noise is generated by the suspension structure, the hydraulic cylinder pressure value is increased until the maximum noise received by the two sound pressure sensors is lower than a preset decibel value. The technical scheme provided by the application increases the hydraulic cylinder pressure value when it is determined that the noise is generated by the suspension structure, enhances the rigidity of the suspension structure, and thus has the technical effect of reducing the noise generated by the suspension structure.

Description

Technical Field

[0001] This invention relates to the field of vehicle noise control technology, and in particular to a noise control method, a suspension system, and an off-road vehicle. Background Technology

[0002] High-end off-road vehicles typically employ a body-on-frame construction. The front-end frame of the body-in-white is relatively far from the A-pillar cantilever. Due to the curvature of the wheel arches and the cross-section of the shotgun, the front-end frame often exhibits low modal characteristics, making reinforcement difficult. The adjacent first suspension mounting point is also affected, resulting in low dynamic stiffness that is difficult to improve, becoming a major risk factor for road noise in high-end off-road vehicles. Reinforcing the front-end frame is constrained by space and weight cost limitations, leading to unsatisfactory improvement results.

[0003] The road noise risk caused by the front end and the first suspension is difficult to solve in real vehicles, and the cost and time required to solve it have become a major challenge in the development of vehicle NVH. Summary of the Invention

[0004] The main objective of this invention is to provide a noise control method, a suspension system, and an off-road vehicle, particularly a noise control method designed to improve the noise problem caused by the suspension structure.

[0005] To achieve the above objectives, this invention proposes a noise control method applied to the suspension system of an off-road vehicle. The suspension system includes: a suspension structure, two hydraulic cylinders, and two sound pressure sensors. The suspension structure has two horizontally extending crossbeams spaced apart vertically, and two vertically extending columns spaced apart horizontally. The columns are respectively connected to the ends of the two crossbeams on the same side. One end of each hydraulic cylinder is connected to the same crossbeam, and the other end is connected to the two columns respectively. The two sound pressure sensors are respectively positioned at the front and rear seats of the vehicle.

[0006] The noise control method includes:

[0007] When it is determined that the noise is generated by the suspension structure, the pressure value of the hydraulic cylinder is increased until the maximum noise received by the two sound pressure sensors is lower than the preset decibel value.

[0008] In one embodiment, the suspension system further includes two acceleration sensors, which are spaced apart in the horizontal direction on the suspension structure;

[0009] Before the step of increasing the hydraulic cylinder pressure value until the maximum noise received by both sound pressure sensors is lower than the preset decibel value when it is determined that the noise is generated by the suspension structure, the method further includes:

[0010] Based on the noise received by the two sound pressure sensors, a noise curve is obtained, and the noise frequency is obtained from the noise curve;

[0011] The acceleration admittance curve is obtained from the acceleration sensor, and the excitation frequency is obtained from the acceleration admittance curve.

[0012] The noise frequency is compared with the excitation frequency;

[0013] If the difference between the noise frequency and the excitation frequency is within the rated range, then the noise is determined to be generated by the suspension structure.

[0014] If the difference between the noise frequency and the excitation frequency exceeds the rated range, it is determined that the noise is generated by other structures.

[0015] In one embodiment, the method further includes, prior to the step of obtaining a noise curve based on the noise received by the two sound pressure sensors and obtaining the noise frequency based on the noise curve:

[0016] Determine if noise is present.

[0017] In one embodiment, the step of determining whether noise exists includes:

[0018] The maximum decibel value received by the two sound pressure sensors is obtained respectively;

[0019] When one of the maximum decibel values ​​received by the two sound pressure sensors is greater than the preset decibel value, it is determined that there is noise at the corresponding sound pressure sensor.

[0020] When the maximum decibel value received by both sound pressure sensors is less than or equal to the preset decibel value, the sound system is determined to be normal.

[0021] In one embodiment, after determining that the noise is generated by the suspension structure, the step of increasing the hydraulic cylinder pressure until the maximum noise received by both sound pressure sensors is lower than a preset decibel value further includes:

[0022] The pressure of the pressure cylinder is adjusted based on the maximum acceleration value obtained from the two acceleration sensors.

[0023] In one embodiment, the step of adjusting the pressure of the pressure cylinder based on the maximum acceleration value obtained from the two acceleration sensors includes:

[0024] When the maximum acceleration value is greater than the preset acceleration value, the two hydraulic cylinders are configured to the first preset pressure value;

[0025] When the maximum acceleration value is less than or equal to the preset acceleration value, the two hydraulic cylinders are configured to the second preset pressure value;

[0026] Wherein, the first preset pressure value is greater than the second preset pressure value.

[0027] In one embodiment, the step of increasing the hydraulic cylinder pressure value until the maximum noise received by both sound pressure sensors is lower than a preset decibel value when it is determined that the noise is generated by the suspension structure includes:

[0028] The pressure values ​​of the two hydraulic cylinders are increased simultaneously, and the pressure values ​​of the two hydraulic cylinders are kept equal.

[0029] The present invention also proposes a suspension system comprising: a suspension structure, two hydraulic cylinders, two sound pressure sensors, and two acceleration sensors; the suspension structure having two horizontally extending crossbeams spaced apart in the vertical direction, and two vertically extending columns spaced apart in the horizontal direction, the columns being respectively connected to the ends of the two crossbeams on the same side; one end of each of the two hydraulic cylinders being connected to the same crossbeam, and the other end being respectively connected to the two columns; the two sound pressure sensors being respectively positioned at the front and rear seats of the vehicle; and the two acceleration sensors being horizontally spaced apart on the suspension structure.

[0030] In one embodiment, the suspension system further includes a control device, which is communicatively connected to the two sound pressure sensors, the two acceleration sensors, and electrically connected to the two hydraulic cylinders; the control device also includes a noise control program for the suspension system stored on the control device and executable on the control device, the noise control program being configured as steps of a noise control method.

[0031] The present invention also proposes an off-road vehicle, the off-road vehicle including a suspension system.

[0032] The technical solution of this invention adjusts the stiffness of the suspension structure by adjusting the pressure of the hydraulic cylinder. The greater the stiffness of the suspension structure, the less noise is generated, or the less noise is generated. Two sound pressure sensors are respectively set in the front and rear positions of the vehicle. When noise is detected in the front or rear positions of the vehicle, the stiffness of the suspension structure is adjusted by the hydraulic cylinder, thereby reducing the noise generated by the suspension structure. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. 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 the structures shown in these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a suspension system according to an embodiment of the present invention;

[0035] Figure 2 This is a flowchart illustrating the first embodiment of the noise control method provided by the present invention;

[0036] Figure 3 This is a flowchart illustrating a second embodiment of the noise control method provided by the present invention.

[0037] Figure 4 This is a flowchart illustrating the third embodiment of the noise control method provided by the present invention.

[0038] Figure 5 This is a flowchart illustrating the fourth embodiment of the noise control method provided by the present invention.

[0039] Figure 6 This is a flowchart illustrating the fifth embodiment of the noise control method provided by the present invention.

[0040] Figure 7 This is a flowchart illustrating the sixth embodiment of the noise control method provided by the present invention.

[0041] Figure 8 This is a flowchart illustrating the seventh embodiment of the noise control method provided by the present invention.

[0042] Explanation of icon numbers:

[0043] 100. Suspension system; 1. Suspension structure; 11. Crossbeam; 12. Column; 2. Hydraulic cylinder.

[0044] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0046] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0047] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0048] High-end off-road vehicles typically employ a body-on-frame construction, resulting in a long distance between the front-end frame and the A-pillar cantilever. Influenced by wheel arch curvature and shotgun cross-section, the front-end frame often exhibits low modal characteristics, making reinforcement difficult. The adjacent first mount point is also affected, exhibiting low dynamic stiffness that is difficult to improve, becoming a major risk point for road noise in high-end off-road vehicles. Reinforcing the front-end frame is constrained by space and weight cost limitations, resulting in unsatisfactory improvements. The road noise risks arising from the front end and the first mount are difficult to resolve in actual vehicles, and the high cost and long development cycle make them a major challenge in NVH development.

[0049] This invention proposes a noise control method.

[0050] Please see Figures 1 to 2 In one embodiment of the present invention, the noise control method is applied to an off-road vehicle suspension system 100. The suspension system 100 includes: a suspension structure 1, two hydraulic cylinders 2, and two sound pressure sensors. The suspension structure 1 has two horizontally extending crossbeams 11 spaced apart in the vertical direction, and two vertically extending columns 12 spaced apart in the horizontal direction. The columns 12 are respectively connected to the ends of the two crossbeams 11 on the same side. This is a suspension structure 1 in the prior art. Based on this, one end of the two hydraulic cylinders 2 is connected to the same crossbeam 11, and the other end is respectively connected to the two columns 12. The stiffness of the suspension structure 1 is adjusted by adjusting the pressure of the hydraulic cylinders 2. The greater the stiffness of the suspension structure 1, the less noise it generates, or the less noise it generates. The two sound pressure sensors are respectively set at the front and rear positions of the vehicle. When noise is detected at the front or rear positions of the vehicle, the stiffness of the suspension structure 1 is adjusted by the hydraulic cylinders 2. The technical solution of the present invention reduces the noise generated by the suspension structure 1 by increasing the pressure value of the hydraulic cylinder 2 when it is determined that the noise is generated by the suspension structure 1, thereby enhancing the rigidity of the suspension structure 1.

[0051] The noise control method steps for the suspension system 100 are as follows: Figure 2 , Figure 2 This is a flowchart illustrating a first embodiment of a noise control method according to the present invention.

[0052] The noise control method includes:

[0053] S3: When it is determined that the noise is generated by the suspension structure 1, the pressure value of the hydraulic cylinder 2 is increased until the maximum noise received by the two sound pressure sensors is lower than the preset decibel value.

[0054] As can be seen from the above steps, before adjusting the stiffness of the suspension structure by adjusting the pressure value of the hydraulic cylinder 2, sound can first be detected in the front and rear seats of the vehicle, and the sound is determined to be noise. Then the stiffness of the suspension structure is adjusted so that the maximum noise received by the sound pressure sensor is lower than the preset decibel value.

[0055] During vehicle operation, many transmission components are in motion, and the vehicle is also affected by road bumps, so the sources of noise are multifaceted. Noise will only be eliminated when the noise originates from the suspension structure 1 and is adjusted. Therefore, it is necessary to determine the source of the noise.

[0056] The noise control method steps for the suspension system 100 are as follows: Figure 3 , Figure 3 This is a flowchart illustrating a second embodiment of a noise control method according to the present invention.

[0057] The suspension system 100 also includes two acceleration sensors, which are spaced apart in the horizontal direction on the suspension structure 1;

[0058] Before the step of increasing the pressure of the hydraulic cylinder 2 until the maximum noise received by both sound pressure sensors is lower than the preset decibel value when it is determined that the noise is generated by the suspension structure 1, the method further includes:

[0059] S21: Obtain a noise curve based on the noise received by the two sound pressure sensors, and obtain the noise frequency based on the noise curve;

[0060] S22: Obtain the acceleration admittance curve from the acceleration sensor, and obtain the excitation frequency from the acceleration admittance curve;

[0061] S23: Compare the noise frequency with the excitation frequency;

[0062] S241: When the difference between the noise frequency and the excitation frequency is within the rated range, it is determined that the noise is generated by the suspension structure 1;

[0063] S242: When the difference between the noise frequency and the excitation frequency exceeds the rated range, it is determined that the noise is generated by other structures.

[0064] By comparing the noise frequency with the excitation frequency, it can be determined whether the noise source is generated by the suspension structure 1.

[0065] It is normal for vehicles to produce some sound during operation, but not all sounds are noise. Only when the sound exceeds a certain decibel level will it be considered noise.

[0066] The noise control method steps for the suspension system 100 are as follows: Figure 4 , Figure 4 This is a flowchart illustrating a third embodiment of a noise control method according to the present invention.

[0067] The procedure further includes, prior to the step of obtaining a noise curve based on the noise received by the two sound pressure sensors and obtaining the noise frequency based on the noise curve:

[0068] S1: Determine if noise is present.

[0069] The loudness of the same sound source heard from different locations inside a vehicle varies depending on the distance. Therefore, two sound pressure sensors are used to detect the loudness of the sound heard in the front and rear seats of the vehicle, respectively.

[0070] The noise control method steps for the suspension system 100 are as follows: Figure 5 , Figure 5 This is a flowchart illustrating the fourth embodiment of a noise control method according to the present invention.

[0071] The step of determining whether noise exists includes:

[0072] S11: Obtain the maximum decibel value received by the two sound pressure sensors respectively;

[0073] S121: When one of the maximum decibel values ​​received by the two sound pressure sensors is greater than the preset decibel value, it is determined that there is noise at the corresponding sound pressure sensor.

[0074] S122: When the maximum decibel value received by the two sound pressure sensors is less than or equal to the preset decibel value, the sound is determined to be normal.

[0075] When one of the two sound pressure sensors detects noise, the stiffness of the suspension structure needs to be adjusted.

[0076] Because the suspension structure 1 experiences different forces at different points during movement, multiple acceleration sensors are provided. In this embodiment, two are used. The greater the acceleration detected by the acceleration sensor, the greater the corresponding force and the more obvious the noise generated.

[0077] The noise control method steps for the suspension system 100 are as follows: Figure 6 , Figure 6 This is a flowchart illustrating the fifth embodiment of a noise control method according to the present invention.

[0078] After the step of increasing the pressure of the hydraulic cylinder 2 until the maximum noise received by both sound pressure sensors is lower than the preset decibel value when it is determined that the noise is generated by the suspension structure 1, the method further includes:

[0079] S31: Adjust the pressure of the pressure cylinder based on the maximum acceleration value obtained from the two acceleration sensors.

[0080] The noise control method steps for the suspension system 100 are as follows: Figure 7 , Figure 7 This is a flowchart illustrating the sixth embodiment of a noise control method according to the present invention.

[0081] Specifically, the step of adjusting the pressure of the pressure cylinder based on the maximum acceleration value obtained from the two acceleration sensors includes:

[0082] S311: When the maximum acceleration value is greater than the preset acceleration value, the two hydraulic cylinders 2 are configured to the first preset pressure value;

[0083] S312: When the maximum acceleration value is less than or equal to the preset acceleration value, the two hydraulic cylinders 2 are configured to the second preset pressure value;

[0084] Wherein, the first preset pressure value is greater than the second preset pressure value.

[0085] The preset acceleration value can be set to multiple values, that is, according to the maximum acceleration value at different gears, the hydraulic cylinder 2 is adjusted to different pressure values, and the suspension structure 1 is adjusted to different stiffness values.

[0086] Since two hydraulic cylinders 2 are installed on the suspension structure 1, in order to make the stiffness of the suspension structure 1 symmetrical and ensure the stability of the overall vehicle structure.

[0087] The noise control method steps for the suspension system 100 are as follows: Figure 8 , Figure 8 This is a flowchart illustrating the seventh embodiment of a noise control method according to the present invention.

[0088] The step of increasing the pressure of the hydraulic cylinder 2 until the maximum noise received by both sound pressure sensors is lower than a preset decibel value when it is determined that the noise is generated by the suspension structure 1 includes:

[0089] S32: Simultaneously increase the pressure values ​​of the two hydraulic cylinders 2, and keep the pressure values ​​of the two hydraulic cylinders 2 equal.

[0090] When the pressure values ​​of the two hydraulic cylinders 2 are adjusted synchronously and kept consistent, the structure has better stability.

[0091] The present invention also proposes a suspension system 100, which includes: a suspension structure 1, two hydraulic cylinders 2, two sound pressure sensors, and two acceleration sensors; the suspension structure 1 has two horizontally extending crossbeams 11 spaced apart in the vertical direction, and two vertically extending columns 12 spaced apart in the horizontal direction, the columns 12 being respectively connected to the ends of the two crossbeams 11 on the same side; one end of the two hydraulic cylinders 2 is connected to the same crossbeam 11, and the other end is respectively connected to the two columns 12; the two sound pressure sensors are respectively installed at the front and rear positions of the vehicle; the two acceleration sensors are spaced apart in the horizontal direction on the suspension structure 1.

[0092] The suspension system 100 also includes a control device, which is communicatively connected to the two sound pressure sensors, the two acceleration sensors, and electrically connected to the two hydraulic cylinders 2; the control device also includes a noise control program for the suspension system 100 stored on the control device and executable on the control device, the noise control program for the suspension system 100 being configured as steps of a noise control method.

[0093] The present invention also proposes an off-road vehicle, which includes a suspension system 100. The specific structure and control method of the suspension system 100 are as described in the above embodiments. Since the off-road vehicle adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0094] Existing off-road vehicles have multiple suspension structures 1. Modifications can be made to different suspension structures 1 based on the aforementioned suspension system, allowing for noise monitoring at various points along the vehicle's suspension structures 1. In particular, the first suspension structure at the front of the off-road vehicle, due to its long distance from the A-pillar cantilever, is often affected by the wheel arch curvature and shotgun cross-section, resulting in a low modal response of the front frame and making reinforcement difficult. The adjacent first suspension mounting point is also affected, exhibiting low dynamic stiffness that is difficult to improve, becoming a major risk point for road noise in high-end off-road vehicles. Modifications based on the aforementioned suspension system not only simplify the structure but also reduce modification costs, shorten the development cycle, and facilitate subsequent maintenance.

[0095] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A noise control method for use in an off-road vehicle suspension system, comprising: The suspension system comprises: a suspension structure having two horizontally extending beams spaced apart in the vertical direction and two vertically extending columns spaced apart in the horizontal direction, the columns being connected to the ends of the same side of the two beams respectively; two hydraulic cylinders, one end of the two hydraulic cylinders being connected to the same beam and the other end being connected to the two columns respectively; two sound pressure sensors arranged at the front and rear positions of the vehicle respectively; two acceleration sensors arranged in the horizontal direction on the suspension structure; The noise control method comprises: obtaining a noise curve according to the noise received by the two sound pressure sensors, and obtaining a noise frequency according to the noise curve; obtaining an acceleration admittance curve according to the acceleration sensors, and obtaining an excitation frequency according to the acceleration admittance curve; comparing the noise frequency with the excitation frequency; when the difference between the noise frequency and the excitation frequency is within a rated range, it is determined that the noise is generated by the suspension structure; when the difference between the noise frequency and the excitation frequency exceeds the rated range, it is determined that the noise is generated by other structures; when it is determined that the noise is generated by the suspension structure, the pressure value of the hydraulic cylinders is increased until the maximum noise received by the two sound pressure sensors is lower than a preset decibel value.

2. The noise control method of claim 1, wherein, Before the step of obtaining a noise curve according to the noise received by the two sound pressure sensors, and obtaining a noise frequency according to the noise curve, the method further comprises: determining whether there is noise.

3. The noise control method of claim 2, wherein, The step of determining whether there is noise comprises: obtaining the maximum decibel value received by the two sound pressure sensors respectively; when one of the maximum decibel values received by the two sound pressure sensors is greater than the preset decibel value, it is determined that there is noise at the corresponding sound pressure sensor; when both of the maximum decibel values received by the two sound pressure sensors are less than or equal to the preset decibel value, it is determined that the sound is normal sound.

4. The noise control method of claim 1, wherein, After the step of increasing the pressure value of the hydraulic cylinders when it is determined that the noise is generated by the suspension structure, until the maximum noise received by the two sound pressure sensors is lower than a preset decibel value, the method further comprises: adjusting the pressure of the hydraulic cylinders according to the maximum acceleration value obtained by the two acceleration sensors.

5. The noise control method of claim 4, wherein, The step of adjusting the pressure of the hydraulic cylinders according to the maximum acceleration value obtained by the two acceleration sensors comprises: when the maximum acceleration value is greater than a preset acceleration value, the two hydraulic cylinders are configured to a first preset pressure value; when the maximum acceleration value is less than or equal to a preset acceleration value, the two hydraulic cylinders are configured to a second preset pressure value; wherein the first preset pressure value is greater than the second preset pressure value.

6. The noise control method of claim 1, wherein, The step of increasing the pressure value of the hydraulic cylinders when it is determined that the noise is generated by the suspension structure, until the maximum noise received by the two sound pressure sensors is lower than a preset decibel value, comprises: synchronously increasing the pressure values of the two hydraulic cylinders and keeping the pressure values of the two hydraulic cylinders equivalent.

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