Steering system noise prediction method based on Block force method

Abstract

The invention belongs to the technical field of automobile steering system noise testing, and particularly relates to a steering system noise prediction method based on a Block force method, and the method comprises the steps: firstly building a steering system noise test board; the method comprises the following steps: arranging a three-way acceleration sensor at a connection point of a connection part of a steering system and a test bench to form a matrix measurement system, knocking at the connection point according to a preset direction, obtaining frequency response functions of all the connection points, and forming a frequency response function matrix; then, keeping the arrangement of the matrix measurement system unchanged, simulating road excitation through a vibration exciter, and recording actual operation condition response data at each connection point in an excitation state; based on the frequency response function matrix and the actual operation condition response data, calculating a Block form of a steering system connection point; and finally, on the basis of a frequency domain substructure method, in combination with a Block force of a steering system and a transfer function of the vehicle, predicting the noise level in the vehicle. The problem that a noise prediction result of a traditional steering system is low in accuracy in the prior art can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile steering system noise testing, and in particular relates to a steering system noise prediction method based on a blocked force method. Background Art

[0002] With the rapid development of the automotive industry, electric power steering systems have been widely used in the automotive field. The rapid development of pure electrification of vehicles and the increasing application of new energy vehicle component technologies have led to increasingly stringent evaluations of vehicle noise. As one of the most important sensory systems in a vehicle, the noise generated by the steering system during operation has a significant impact on in-vehicle comfort. The sources of steering system noise are complex and diverse, including friction in mechanical components, gear meshing, and flow noise in hydraulic components. To improve vehicle quality, accurately predicting the noise level of the steering system during bench testing is crucial.

[0003] Traditional steering system noise prediction methods are typically performed on a specific test bench. However, due to differences in stiffness and damping between the test bench and the actual vehicle, the test results cannot accurately reflect the steering system's noise performance on the actual vehicle. Furthermore, traditional methods struggle to obtain reliable predictions across a wide frequency band, with significant errors occurring in low-frequency bands.

[0004] Existing technologies typically use direct measurement methods to characterize steering system noise. However, due to the complex internal structure of steering systems and the difficulty in accurately describing the interactions between components, the accuracy and reliability of the predictions are significantly limited. Furthermore, traditional methods are limited by the stiffness of the mounting structure and perform poorly at low frequencies. To address these issues, a method is needed that can accurately characterize steering system noise sources and predict their noise performance under different vehicle assembly conditions. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a steering system noise prediction method based on a blocked force method, so as to solve the problem of low accuracy of traditional steering system noise prediction results in the prior art.

[0006] The basic solution provided by the present invention is a steering system noise prediction method based on a blocked force method, comprising:

[0007] S1: Build a steering system noise test bench including a steering system and a test bench;

[0008] S2: Three-axis acceleration sensors are placed at the connection points between the steering system and the test bench to form a matrix measurement system. The connection points are then struck in preset directions to obtain the frequency response functions of the connection points. The frequency response functions of all connection points are then recorded to form a frequency response function matrix.

[0009] S3: Maintaining the layout of the matrix measurement system unchanged, simulate road excitation using a vibrator, record the dynamic acceleration of the matrix measurement system at each connection point under excitation, and generate actual operating condition response data;

[0010] S4: Calculate the blocked force of the steering system connection point based on the frequency response function matrix and the actual operating condition response data;

[0011] S5: Predict the interior noise level based on the frequency domain substructuring method, combined with the blocked force of the steering system and the vehicle transfer function.

[0012] Furthermore, the steering system noise test bench includes a test bench, an exciter, a fixture and a torque device, wherein the exciter is used to simulate road excitation, the fixture is used to fix the steering system on the test bench, and the torque device is used to apply torque;

[0013] The rigidity of the clamp is higher than the vehicle side rigidity and lower than the steering rack side rigidity.

[0014] Furthermore, the S2 includes:

[0015] S2-1: Install two three-axis acceleration sensors at the connection point between the steering system and the test bench to form a matrix measurement system;

[0016] S2-2: Use the hammering method to strike the connection point in the X, Y, and Z directions to obtain the frequency response function;

[0017] S2-3: Record the frequency response functions between all connection points to form a frequency response function matrix.

[0018] Furthermore, the S3 includes:

[0019] S3-1: Maintaining the same arrangement of the three-axis accelerometers in the matrix measurement system, a load in the 0-40 Hz range was applied via the test bench shaker, with the primary excitation concentrated at 13-15 Hz. A sine wave was superimposed to simulate road excitation.

[0020] S3-2: Record the dynamic acceleration of each connection point under the excitation state at a preset sampling frequency to generate actual operating condition response data.

[0021] Furthermore, the Blocked force expression for calculating the steering system connection point in S4 is:

[0022]

[0023] Among them, [F b ] represents the Blocked force vector, represents the pseudo-inverse of the frequency response function matrix, [V] dyn represents the dynamic acceleration vector;

[0024] During the Blocked force calculation process, if the singular value is less than 100, ≤1% of the data points are deleted.

[0025] Further, the S5 includes:

[0026] S5-1: Calculate the contact force after the Blocked force conversion based on the frequency substructure method and the target receiving vehicle;

[0027] S5-2: Calculate the product of the contact force and the transfer function matrix of the target receiving vehicle to obtain the noise level of the target receiving vehicle.

[0028] An electronic device includes a processor and a memory, wherein the memory stores programs or instructions, and the processor executes any of the above-mentioned steering system noise prediction methods based on the blocked force method by calling the programs or instructions stored in the memory.

[0029] A computer-readable storage medium stores a program or instruction, wherein the program or instruction enables a computer to execute the steering system noise prediction method based on the blocked force method as described in any one of the above items.

[0030] The principles and advantages of the present invention are as follows: In the technical solution of this application, a transfer path analysis method based on the blocked force method is proposed, which can directly measure the equivalent force instead of the excitation source to analyze the structural vibration, and combine the frequency response function (FRF) to predict the noise transfer path, thereby achieving accurate noise prediction. Specifically, first, a steering system test bench that meets the test requirements is built. In the test bench, the steering system is fixed to the test bench through a fixture, and an exciter is used to apply an excitation force to the test bench to achieve real road excitation of the steering system. The torque device applies torque to the test bench.

[0031] Subsequently, three-axis acceleration sensors were arranged at the connection points between the steering system and the test bench to form a matrix measurement system. After the arrangement was completed, static and dynamic tests were carried out in sequence. The static test was to hammer all connection points in the X, Y, and Z directions to obtain the frequency response function matrix; the dynamic test was to keep the layout of the three-axis acceleration sensors in the matrix measurement system unchanged, simulate road excitation through the exciter, record the dynamic acceleration of all connection points under the excitation state, and form the actual operating condition response data.

[0032] After obtaining the frequency response function matrix and actual operating condition response data, the blocked force is calculated. Once the blocking force is calculated, the noise level inside the target vehicle is predicted based on the blocking force and the target vehicle's transfer function, using the frequency-domain substructuring method. The frequency-domain substructuring method can treat the steering system (source) and the vehicle (receiver) as independent substructures, characterizing their dynamic characteristics respectively. The blocked force is used to describe the source characteristics of the steering system and is independent of the receiver. Therefore, the blocked force method, combined with the acoustic transfer function of any vehicle, can effectively predict the contribution of the noise transfer path, and thus the noise level inside the vehicle.

[0033] Therefore, the advantage of this application is that the steering system noise prediction method generated based on the Blocked force method can independently characterize the noise characteristics of the steering system without relying on the vehicle environment, and has the advantages of high efficiency, low cost and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a flowchart of an embodiment of the present invention;

[0035] Figure 2 A logic block diagram of an embodiment of the present invention;

[0036] Figure 3 Schematic diagram of the structure based on the frequency domain substructure method in an embodiment of the present invention;

[0037] Figure 4 A schematic diagram of the electronic device structure. DETAILED DESCRIPTION

[0038] The following is further described in detail through specific implementation methods:

[0039] The symbols in the drawings of the specification include: electronic device 400 , processor 401 , memory 402 , input device 403 , and output device 404 .

[0040] Identifying vibration and noise source characteristics has always been a critical task in automotive development. Addressing the limitations of traditional path analysis in obtaining excitation, this application proposes a steering system noise prediction method based on the blocked force approach. Its core approach is to simplify complex excitation sources into equivalent blocked force combinations. This method, combined with the acoustic transfer characteristics of the test bench and the steering system mounting points, allows for direct calculation of radiated noise. The core innovation lies in characterizing the inherent characteristics of the noise source through the equivalent force at the connection point. This force remains constant across different receiving systems (e.g., different vehicle models). The basic principles are as follows:

[0041] 1. The transmission path between the noise source (steering system) and the receiving system (vehicle) can be described by a frequency response function;

[0042] 2. Blocked force is an independent property of the noise source and is not affected by the rigidity or damping of the receiving system.

[0043] Therefore, based on the above principle description, the embodiment is basically as shown in the attached Figure 1 and Figure 2 FIG. 1 shows a steering system noise prediction method based on a Blocked Force method, comprising:

[0044] S1: Build a steering system noise test bench including a steering system and a test bench; wherein, the steering system noise test bench includes a test bench, an exciter, a fixture and a torque device, the exciter is used to simulate road excitation, the fixture is used to fix the steering system on the test bench, and the torque device is used to apply torque. Its core function is to simulate the torque load under the dynamic working conditions of the actual vehicle, so as to reproduce the friction torque between the tire and the ground when the vehicle is driving, such as simulating the steering wheel return torque or the impact torque of bumpy roads. Secondly, by controlling the frequency and amplitude of the torque (such as 0-40Hz dynamic load, main frequency 13-15Hz), the vibration and noise characteristics of the steering system are stimulated to ensure that the test conditions are consistent with actual use.

[0045] The stiffness of the fixture is higher than the vehicle side stiffness and lower than the steering rack side stiffness, and the steering rack side belongs to the structure inside the vehicle; the stiffness design of the fixture in this application is, first, to avoid the deformation of the fixture itself interfering with the test. If the stiffness of the fixture is lower than the vehicle side stiffness, the fixture will produce significant deformation under dynamic load, resulting in distortion of the vibration response of the installation point and inability to accurately characterize the steering system characteristics; second, to prevent excessive constraint of the steering system. If the stiffness of the fixture is close to or higher than the steering rack side stiffness, it will suppress the natural vibration mode of the steering system and mask high-frequency noise (such as gear meshing noise).

[0046] S2: Three-axis acceleration sensors are placed at the connection points between the steering system and the test bench to form a matrix measurement system. The connection points are struck in preset directions to obtain the frequency response functions of the connection points. The frequency response functions of all connection points are recorded to form a frequency response function matrix. S2 includes:

[0047] S2-1: Install two three-axis acceleration sensors at the connection point between the steering system and the test bench to form a matrix measurement system;

[0048] S2-2: Use the hammering method to strike the connection point in the X, Y, and Z directions to obtain the frequency response function;

[0049] S2-3: Record the frequency response functions between all connection points to form a frequency response function matrix.

[0050] In this embodiment, there are two connection points between the steering system and the test bench, namely point A and point B. Two three-axis acceleration sensors are arranged near point A and point B respectively to form a matrix measurement system. The matrix measurement system constructed in this application has a size of 6×12, 6 degrees of freedom, and 4 three-axis acceleration sensors.

[0051] Based on the generated matrix measurement system, the inherent force of the steering system is measured on the test bench using the hammer method. This is a static test. Specifically, a nylon head hammer is used to strike the connection point in the X, Y, and Z directions to obtain the frequency response function. Specifically, the force applied by the nylon head hammer is recorded during the striking, and the test data of the three-axis acceleration sensor in the matrix measurement system at this time is obtained. Finally, the frequency response function during the static test is obtained based on the proportional relationship between the test data and the striking force. At the same time, the generated frequency response function is valid in the frequency band of 200-1500Hz, and the frequency resolution is not less than 1.25Hz. This requirement is mainly based on the principle of signal processing, that is, for high-frequency signals, the gear meshing harmonics can be distinguished; for low-frequency signals, the resonance peaks can be accurately identified to avoid spectrum leakage.

[0052] According to the above method, static tests are performed on all connection points in turn to obtain the frequency response functions of the three-axis acceleration sensors (X / Y / Z directions) at all connection points, and the frequency response function matrix is generated. The expression is:

[0053]

[0054] S3: Maintaining the layout of the matrix measurement system unchanged, simulate road excitation using a shaker, record the dynamic acceleration of the matrix measurement system at each connection point under excitation, and generate actual operating condition response data. S3 includes: S3-1: Maintaining the layout of the three-axis acceleration sensors in the matrix measurement system unchanged, apply a load in the range of 0-40Hz through the test bench shaker, with the main excitation concentrated in the range of 13-15Hz, and superimpose a sine wave to simulate road excitation;

[0055] S3-2: Record the dynamic acceleration of each connection point under the excitation state at a preset sampling frequency to generate actual operating condition response data;

[0056] In this embodiment, after the static test of the steering system test bench in S2, a dynamic test of the steering system test bench is performed. First, the arrangement of the three-axis acceleration sensors in the matrix measurement system constructed in S2 above is maintained unchanged, the vehicle speed (10-15 km / h) is simulated by the torque device of the test bench, and an exciting force is applied to the test bench through the exciter to simulate road excitation; the load generated by the applied exciting force ranges from 0 to 40 Hz, and the main excitation is concentrated at 13-15 Hz, with a superimposed sine wave; in this state, the dynamic acceleration of the three-axis acceleration sensors at each connection point under the excitation state is recorded at a sampling frequency of not less than 8 kHz to obtain the response data of the steering system under actual working conditions.

[0057] After obtaining the frequency response function matrix under the static test and the actual operating condition response data under the dynamic test, step S4 is executed: based on the frequency response function matrix and the actual operating condition response data, the blocked force of the steering system connection point is calculated;

[0058] The Blocked force expression is:

[0059]

[0060] Among them, [F b ] represents the Blocked force vector, represents the pseudo-inverse of the frequency response function matrix, [V] dyn represents the dynamic acceleration vector;

[0061] In solving the above Blocked force, the matrix inversion method is used to ensure that the singular value is less than 100 and at most 1% of the data points are deleted.

[0062] Finally, based on the blocked force calculated above, noise prediction is performed. Specifically, S5 predicts the interior noise level based on the frequency domain substructuring method, combining the blocked force of the steering system and the vehicle transfer function. S5 includes:

[0063] S5-1: Calculate the contact force after the Blocked force conversion based on the frequency substructure method and the target receiving vehicle;

[0064] S5-2: Calculate the product of the contact force and the transfer function matrix of the target receiving vehicle to obtain the noise level of the target receiving vehicle.

[0065] In this embodiment, if Figure 3 As shown, the physical model on the left represents source A, which is the steering system. The excitation source acts on point 1 and is connected to the FBS structure in the middle, which is the frequency substructure, through point 2. The right side includes receiving vehicles B and C. Both receiving vehicles B and C receive data transmitted by FBS through point 3, and then receive noise through point 5, and analyze the noise level.

[0066] Therefore, based on the above physical model principles, the contact force is first calculated according to the blocked force, and the expression is:

[0067]

[0068] in represents the impedance matrix of source A, represents the impedance matrix of the receiving vehicle B, K -1 Represents the inverse matrix of the soft connection, which can reflect the flexible characteristics of the frequency domain substructure connection. Indicates the blocked force at the location of excitation source A.

[0069] The contact force is calculated Then, the noise signal of the receiving vehicle is predicted by multiplying the transfer function matrix of the receiving vehicle with the contact force. Taking the receiving vehicle B as an example, it is calculated by the following expression:

[0070]

[0071] in, is the transfer function matrix of the receiving vehicle B, and the contact force After multiplication, the noise signal at point 5 of receiving vehicle B is obtained

[0072] In addition, in order to ensure the accuracy of the noise level predicted by the technical solution of this application, the measured noise is compared with the predicted noise for verification; at the same time, the calculated Blocked force data is transmitted to different receiving vehicles, such as Figure 3 The receiver vehicle C is shown to predict the noise performance of the steering system on different vehicles.

[0073] In another embodiment of this embodiment, the electronic device for noise prediction is protected. Specifically, Figure 4 As shown, an electronic device is also included, and the electronic device 400 includes one or more processors 401 and a memory 402.

[0074] The processor 401 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 400 to perform desired functions.

[0075] The memory 402 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 401 may execute the program instructions to implement the steering system noise prediction method based on the blocked force method of any embodiment of the present invention described above and / or other desired functions. Various contents such as initial external parameters, thresholds, etc. may also be stored in the computer-readable storage medium.

[0076] In one example, electronic device 400 may further include an input device 403 and an output device 404, which are interconnected via a bus system and / or other connection mechanisms (not shown). Input device 403 may include, for example, a keyboard, a mouse, etc. Output device 404 may output various information to the outside, including warning information, braking force, etc. Output device 404 may include, for example, a display, a speaker, a printer, a communication network, and remote output devices connected thereto.

[0077] Of course, to simplify, Figure 4 Only some of the components related to the present invention in the electronic device 400 are shown, and components such as buses, input / output interfaces, etc. are omitted. In addition, the electronic device 400 may further include any other appropriate components according to specific application scenarios.

[0078] In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, cause the processor to perform the steps of a steering system noise prediction method based on a blocked force method provided by any embodiment of the present invention.

[0079] The computer program product may be written in any combination of one or more programming languages to implement the operations of embodiments of the present invention, including object-oriented programming languages such as Java, C++, and conventional procedural programming languages such as C or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's computing device, as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0080] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, causes the processor to execute the steps of a steering system noise prediction method based on a blocked force method provided in any embodiment of the present invention.

[0081] The computer-readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can, for example, include but is not limited to a system, device or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0082] The above are only embodiments of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme are not described in detail here. Ordinary technicians in the field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A steering system noise prediction method based on a blocked force method, characterized by: include: S1: Build a steering system noise test bench including a steering system and a test bench; S2: Three-axis acceleration sensors are placed at the connection points between the steering system and the test bench to form a matrix measurement system. The connection points are then struck in preset directions to obtain the frequency response functions of the connection points. The frequency response functions of all connection points are then recorded to form a frequency response function matrix. S3: Maintaining the layout of the matrix measurement system unchanged, simulate road excitation using a vibrator, record the dynamic acceleration of the matrix measurement system at each connection point under excitation, and generate actual operating condition response data; S4: Calculate the blocked force of the steering system connection point based on the frequency response function matrix and the actual operating condition response data; S5: Predict the interior noise level based on the frequency domain substructuring method, combined with the blocked force of the steering system and the vehicle transfer function.

2. The method for predicting steering system noise based on the Blocked Force method according to claim 1, characterized in that: The steering system noise test bench includes a test bench, an exciter, a fixture and a torque device, wherein the exciter is used to simulate road excitation, the fixture is used to fix the steering system on the test bench, and the torque device is used to apply torque; The rigidity of the clamp is higher than the vehicle side rigidity and lower than the steering rack side rigidity.

3. The steering system noise prediction method based on the blocked force method according to claim 1, characterized in that: The S2 includes: S2-1: Install two three-axis acceleration sensors at the connection point between the steering system and the test bench to form a matrix measurement system; S2-2: Use the hammering method to strike the connection point in the X, Y, and Z directions to obtain the frequency response function; S2-3: Record the frequency response functions between all connection points to form a frequency response function matrix.

4. The method for predicting steering system noise based on the Blocked Force method according to claim 3, characterized in that: The S3 includes: S3-1: Maintaining the same arrangement of the three-axis accelerometers in the matrix measurement system, a load in the 0-40 Hz range was applied via the test bench shaker, with the primary excitation concentrated at 13-15 Hz. A sine wave was superimposed to simulate road excitation. S3-2: Record the dynamic acceleration of each connection point under the excitation state at a preset sampling frequency to generate actual operating condition response data.

5. The method for predicting steering system noise based on the Blocked Force method according to claim 1, characterized in that: The Blocked force expression for calculating the steering system connection point in S4 is: Among them, [F b ] represents the Blocked force vector, represents the pseudo-inverse of the frequency response function matrix, [V] dyn represents the dynamic acceleration vector; During the Blocked force calculation process, if the singular value is less than 100, ≤1% of the data points are deleted.

6. The method for predicting steering system noise based on the Blocked Force method according to claim 5, characterized in that: The S5 includes: S5-1: Calculate the contact force after the Blocked force conversion based on the frequency substructure method and the target receiving vehicle; S5-2: Calculate the product of the contact force and the transfer function matrix of the target receiving vehicle to obtain the noise level of the target receiving vehicle.

7. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a program or instruction, and the processor executes the steering system noise prediction method based on the blocked force method according to any one of claims 1 to 6 by calling the program or instruction stored in the memory.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program or instruction, and the program or instruction enables a computer to execute the steering system noise prediction method based on the blocked force method as described in any one of claims 1 to 6.

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