A vehicle low-frequency vertical vibration comfort evaluation system and method

Abstract

The present invention discloses a vehicle low-frequency vertical vibration comfort evaluation system and method. The system comprises: obtaining a first functional relationship between road excitation frequency and user scenario based on the vehicle speed and mileage distribution ratios of various levels of roads; obtaining a second functional relationship between the vibration frequency and amplitude magnification factor of the suspension system based on a four-channel endurance test bench; obtaining a vibration frequency-vibration comfort evaluation curve based on the first functional relationship between the road excitation frequency and user scenario and the second functional relationship between the vibration frequency and amplitude magnification factor of the suspension system, and accumulating the amplitude within a set frequency range in the curve to obtain a vehicle low-frequency vertical vibration comfort evaluation index. The present invention comprehensively considers road frequency, vehicle suspension vibration transmission, and human body vibration frequency to evaluate the vehicle's low-frequency vibration comfort level in most user usage scenarios, which is more in line with the user's actual situation, more scientific, and more conducive to guiding vehicle design and development.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle comfort evaluation, and in particular relates to a vehicle low-frequency vertical vibration comfort evaluation system and method. Background Art

[0002] Low-frequency vertical vibration comfort refers to the surging and bumpy sensations transmitted from the suspension system (springs and shock absorbers) to the vehicle body under random road excitations of 0.5-5Hz. Poorly designed low-frequency vibration comfort can easily cause motion sickness and vomiting in passengers. Generally speaking, a vehicle's low-frequency vibration comfort is determined after the spring and shock absorber design is complete. Therefore, optimizing the design parameters of the suspension springs and shock absorbers in the early stages of the design process to improve the vehicle's low-frequency vibration comfort is a key technology for OEMs.

[0003] One existing technique involves the vehicle ride comfort test specified in GBT4970-2009, a test method for motor vehicle ride comfort. This method uses the root mean square (RMS) value of the combined weighted acceleration above the seat cushion, seat back, and footrest to assess subjective human comfort. However, this method's results are highly dependent on the quality of the test road and the test vehicle speed, and cannot accurately reflect user experience.

[0004] A second existing technique involves measuring the vibration transfer characteristics of a vehicle's suspension system using a frequency sweep on a vibration test bench. The vibrations are then frequency-weighted based on the human body's sensitivity to vibration frequency, resulting in a root mean square (RMS) acceleration value to evaluate the vehicle's ride comfort. This method accurately assesses the vibration transfer characteristics of the vehicle's suspension system itself. However, since the vehicle is traveling on a road, it cannot reflect the vibration response of the vehicle on different roads. Furthermore, by adjusting the stiffness and damping coefficient of the suspension springs, the suspension's frequency offset and amplitude amplification factor are optimized. This results in a vehicle's ride comfort that meets the needs of most users. Summary of the Invention

[0005] In order to more accurately evaluate the low-frequency vertical vibration comfort of a vehicle, the present invention proposes a vehicle low-frequency vertical vibration comfort evaluation system and method.

[0006] A vehicle low-frequency vertical vibration comfort evaluation system for achieving one of the objectives of the present invention includes:

[0007] A user scenario function acquisition module is used to obtain a first functional relationship between road stimulus frequency and user scenario based on vehicle speeds and mileage distribution ratios of various levels of roads;

[0008] Vehicle suspension vibration transfer function acquisition module: used to obtain the second functional relationship between the vibration frequency and amplitude amplification factor of the suspension system based on a four-channel endurance test bench;

[0009] The comfort calculation module is configured to generate a vibration frequency-comfort evaluation curve based on a first functional relationship between the road excitation frequency and the user scenario and a second functional relationship between the suspension system's vibration frequency and the amplitude amplification factor. The module then accumulates the amplitudes within a set frequency range within the curve to obtain a vehicle low-frequency vertical vibration comfort evaluation index. The comfort index is used to evaluate the vehicle's low-frequency vertical vibration comfort, with smaller values ​​representing greater comfort.

[0010] Furthermore, in the comfort calculation module, the first functional relationship between the road excitation frequency and the user scenario is multiplied by the second functional relationship to obtain a vibration frequency-vibration comfort evaluation curve.

[0011] Furthermore, in the user scenario function acquisition module, a method for calculating the first functional relationship between the road stimulus frequency and the user scenario includes:

[0012] In the user scenario function acquisition module, a method for acquiring a first functional relationship between the road stimulus frequency and the user scenario includes:

[0013] Calculate the road excitation frequencies corresponding to various roads according to the road wavelength range; the calculation method includes: setting the vehicle speed of each road to [v1, v2, v3, ..., v m-1 、v m ], set the road wavelength range to [λ1, λ2, λ3, ..., λ n-1 ,λ n ]; vehicle speed is v i The road corresponds to a certain road wavelength λ j The road excitation frequency is v i / λ j For example, the road excitation frequencies corresponding to the road speed v1 are v1 / λ1, v1 / λ2, ..., v1 / λ n-1 、v1 / λ n ; The road excitation frequencies corresponding to the road with a vehicle speed of v2 are v2 / λ1, v2 / λ2, ..., v2 / λ n-1 、v2 / λ n .

[0014] The road excitation frequency within the set range is divided into multiple intervals to obtain multiple road excitation frequency intervals, and the total number of occurrences of each road excitation frequency interval on each road is counted as the number of excitations; for example: all road excitation frequencies corresponding to all roads falling within the set range are divided into multiple intervals to obtain multiple road excitation frequency intervals: [f 11 ,f 12 ],[f 21 ,f 22 ],[f 31 ,f32 ],[f 41 ,f 42 ]……; Count the total number of each road excitation frequency interval that appears on each road as the number of excitations, that is, assuming that the road excitation frequencies corresponding to the vehicle speed v1 are v1 / λ1, v1 / λ2, …, v1 / λ n-1 、v1 / λ n ;Statistics v1 / λ1, v1 / λ2,…, v1 / λ n-1 、v1 / λ n The n values ​​fall into each road excitation frequency interval [f 11 ,f 12 ],[f 21 ,f 22 ],[f 31 ,f 32 ],[f 41 ,f 42 ]...; the road excitation frequencies corresponding to the road with a vehicle speed of v2 are v2 / λ1, v2 / λ2,..., v2 / λ n-1 、v2 / λ n The n values ​​in fall into each road excitation frequency interval [f 11 ,f 12 ],[f 21 ,f 22 ],[f 31 ,f 32 ],[f 41 ,f 42 ]……; and so on, no longer repeat.

[0015] According to the total number and the mileage distribution ratio of each level of road, the weighted cumulative value of the number of excitations for each road excitation frequency interval corresponding to each level of road is obtained; for example, the road with a vehicle speed of v1 corresponds to n1 road excitation frequencies (f1~f n1 ) falls into the road excitation frequency range [f 11 ,f 12 ] is N1 times; assuming that the mileage of the road with a speed of v1 is p1, the road excitation frequency interval [f 11 ,f 12 ]The weighted cumulative value of the number of excitations corresponding to the road with a vehicle speed of v1 is equal to N1×p1.

[0016] The weighted cumulative values ​​of the number of excitations for each level of road in each road excitation frequency interval are summed to obtain the user scenario weight corresponding to each road excitation frequency interval; for example: Assuming that the road excitation frequency interval [f 11 ,f 12] The weighted cumulative value of the number of excitations corresponding to the road with a vehicle speed of v1 is equal to N1×p1; the road excitation frequency interval [f 11 ,f 12 ] The weighted cumulative value of the number of excitations for a road with a vehicle speed of v2 is equal to N2×p2; the road excitation frequency interval [f 11 ,f 12 The sum of the weighted cumulative values ​​of the number of excitations of all roads corresponding to ] is N1×p1+N2×p2+… and the resulting sum is the road excitation frequency interval [f 11 ,f 12 ] corresponding to the user scenario weight; preferably, the road excitation frequency interval [f 11 ,f 12 ].

[0017] A fitting calculation is performed based on each road excitation frequency interval and the corresponding user scenario weight to obtain a fitting relationship between the road excitation frequency and the user scenario weight. The fitting relationship is the first functional relationship between the road excitation frequency and the user scenario.

[0018] Furthermore, the method for obtaining the weighted value of the road excitation frequency statistics includes:

[0019] The weighted value of the road excitation frequency statistics = the total number of road excitation frequency intervals that appear on roads of this level × the mileage distribution ratio of roads of this level.

[0020] Furthermore, when performing fitting calculation based on the excitation frequency of each road segment and the corresponding user scenario weight, it also includes: taking the mean or arithmetic midpoint of the excitation frequency of each road segment as the value of the road excitation frequency during fitting.

[0021] Furthermore, the method for obtaining the user scenario weight corresponding to each road excitation frequency interval includes:

[0022]

[0023] where value i,j V represents the weighted value of the number of times the jth road excitation frequency interval corresponds to the i-th road grade; j represents the user scenario weight corresponding to the j-th road excitation frequency.

[0024] Furthermore, the method for calculating and obtaining the second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system includes:

[0025] Set the sine sweep frequency of the four-channel test bench to the first setting range; set the sweep rate to the first rate value;

[0026] Calculate the corresponding relationship between each set vertical vibration frequency and the four-channel test bench vibration acceleration according to the set sinusoidal sweep frequency and the set vibration amplitude;

[0027] Measure and obtain the corresponding relationship between each set vertical vibration frequency and the vibration acceleration of the vehicle lifting point;

[0028] The corresponding relationship between each vertical vibration frequency and the vibration acceleration of the four-channel test bench and the corresponding relationship between each vertical vibration frequency and the vibration acceleration of the vehicle lifting point are calculated to obtain a second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system.

[0029] Furthermore, the second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system = the corresponding relationship between the vibration acceleration of the four-channel test bench and the vibration frequency / the corresponding relationship between the vibration acceleration of the vehicle lifting point and the vibration frequency.

[0030] Furthermore, it also includes a comfort evaluation optimization module: used to obtain a third functional relationship between the vertical vibration frequency and the human perception value; according to the first functional relationship, the second functional relationship and the third functional relationship, an optimized vehicle frequency-vibration comfort evaluation curve is obtained, and the amplitude of the set frequency range in the curve is accumulated to obtain an optimized vehicle low-frequency vertical vibration comfort evaluation index.

[0031] In the comfort evaluation optimization module, the first functional relationship between the road excitation frequency and the user scenario is multiplied by the second functional relationship and the third functional relationship to obtain an optimized vibration frequency-vibration comfort evaluation curve.

[0032] The third functional relationship includes:

[0033]

[0034] Where:

[0035] y3(f) is the human perception value; f represents the vertical vibration frequency.

[0036] A method for evaluating vehicle low-frequency vertical vibration comfort to achieve the second objective of the present invention includes:

[0037] The first functional relationship between the road excitation frequency and the user scenario is obtained based on the vehicle speeds and mileage distribution ratios of various levels of roads;

[0038] The second functional relationship between the vibration frequency and amplitude amplification factor of the suspension system is obtained based on a four-channel endurance test bench;

[0039] Based on the first functional relationship and the second functional relationship, a vibration frequency-vibration comfort evaluation curve is obtained, and the amplitude of a set frequency range in the curve is accumulated to obtain a vehicle low-frequency vertical vibration comfort evaluation index. The comfort index is used to evaluate the low-frequency vertical vibration comfort of the vehicle, and a smaller value indicates better comfort.

[0040] The beneficial effects of the present invention include:

[0041] This method first studies road mileage and road grade, as well as user vehicle usage scenarios, to develop a first functional relationship between road excitation frequency and user scenario. It then measures the vibration transmission of the vehicle suspension system on a four-channel endurance test bench, forming a second functional relationship. Finally, it analyzes the human body's response to vibration frequency to develop a third functional relationship, a vehicle low-frequency vertical vibration comfort index that takes into account road frequency, vehicle suspension vibration transmission, and human vibration frequency. This index can be used to evaluate a vehicle's low-frequency vibration comfort level in most user scenarios, better reflecting actual user experience, providing a more scientific and helpful guide for vehicle design and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the framework of the system of the present invention;

[0043] Figure 2 This is a schematic diagram of the four-channel bench test of the present invention;

[0044] Figure 3 It is a schematic diagram of the vibration frequency-vibration comfort evaluation curve of the present invention. DETAILED DESCRIPTION

[0045] The following detailed description is intended to explain the technical solutions of the present invention claims, so that those skilled in the art can understand the present claims. The scope of protection of the present invention is not limited to the specific implementation structures described below. Any implementation schemes created by those skilled in the art that incorporate the technical solutions of the present invention claims but differ from the following detailed descriptions are also within the scope of protection of the present invention.

[0046] Road spatial frequency refers to the number of fluctuations in road surface roughness within a unit distance, usually measured as "several wavelengths per meter length", with the unit of (1 / m). It is the reciprocal of the road wavelength. The road wavelength (λ) represents the minimum distance of the periodically repeated parts of these fluctuations or unevenness, usually measured in meters (m), reflecting the degree of unevenness of the road surface on a spatial scale. In the fields of road engineering, vehicle dynamics, and road wear research, road spatial frequency is an important parameter used to evaluate the driving quality of the road surface, the smoothness of vehicle driving, and the wear effect on vehicle components. The low-frequency vibration comfort of the vehicle is closely related to the road spatial frequency itself, so the embodiment of the present invention combines the vehicle driving road to evaluate the low-frequency vibration comfort of the vehicle. Studies have shown that the road spatial frequency distribution of different road grades is 0.01 to 10; the design speed and user driving evaluation speed of different road grades are shown in Table 1 below.

[0047] Table 1

[0048]

[0049] Example 1

[0050] A vehicle low-frequency vertical vibration comfort evaluation system, comprising:

[0051] A user scenario function acquisition module is configured to obtain a first functional relationship between road excitation frequency and user scenario based on vehicle speeds and mileage distribution ratios of various road levels. The various road levels are shown in Table 1 and are divided into five levels in this embodiment.

[0052] Vehicle suspension vibration transfer function acquisition module: used to obtain the second functional relationship between the vibration frequency and amplitude amplification factor of the suspension system based on a four-channel endurance test bench;

[0053] Comfort calculation module: used to obtain a vibration frequency-vibration comfort evaluation curve based on a first functional relationship between the road excitation frequency and the user scenario and a second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system, and to accumulate the amplitude within a set frequency range in the curve to obtain a vehicle low-frequency vertical vibration comfort evaluation index.

[0054] In some embodiments, in the user scenario function acquisition module, a method for acquiring a first functional relationship between road stimulus frequency and user scenario includes:

[0055] 1.1. Calculating the road excitation frequencies corresponding to various road types based on the road wavelength range. In this embodiment, the road excitation frequencies corresponding to various road grades at various road wavelengths are calculated based on the formula: Road Excitation Frequency (Hz) = Vehicle Speed ​​(m / s) / Road Wavelength (m). Table 2 below shows that the road excitation frequencies corresponding to various road grades at various road wavelengths are obtained. In this embodiment, the vehicle speed is the average speed for each road grade. The road wavelength range is 0.1 m to 100 m. It can be seen that faster vehicle speeds generate higher vibration frequencies for the same road surface roughness. The shorter the road wavelength for the road surface roughness, that is, the more uneven the road surface, the higher the vibration frequency generated.

[0056] Table 2

[0057]

[0058]

[0059] 1.2. Divide the road excitation frequency within the set range into multiple intervals to obtain multiple road excitation frequency intervals, and count the total number of road excitation frequencies belonging to each road excitation frequency interval for each level of road as the number of excitations;

[0060] Specifically, as shown in Table 3, the road excitation frequency within the set range in Table 2 ([0.45 Hz, 5.05 Hz] in this embodiment) is divided into multiple intervals, and the number of each road excitation frequency falling into each road excitation frequency interval under each road grade in Table 2 is counted. For example, the second column in Table 2 shows the road excitation frequencies corresponding to the road of 30 km / h. The statistical results are shown in Table 3. It can be seen that there are 34 road excitation frequency values ​​(values ​​in the second column of Table 2) for Class 4 roads with an average speed of 30 km / h that belong to or fall into the road excitation frequency interval of [0.45 Hz to 0.54 Hz); there are 50 road excitation frequency values ​​(values ​​in the third column of Table 2) for Class 3 roads with an average speed of 45 km / h that belong to or fall into the excitation frequency interval of [0.55 Hz to 0.64 Hz).

[0061] Table 3

[0062]

[0063]

[0064] 1.3. Based on the total number and the mileage distribution percentage of each road grade, a weighted cumulative value of the number of excitations for each road grade corresponding to each road excitation frequency interval is obtained. The mileage distribution percentage for each road grade is shown in Table 4 below. The statistical data in this embodiment is the mileage distribution percentage for each road grade nationwide.

[0065] Table 4

[0066]

[0067] 1.4. Sum the weighted cumulative values ​​of the number of excitations for each road excitation frequency interval corresponding to each level of road to obtain a user scenario weight corresponding to each road excitation frequency interval; preferably, the method for calculating the user scenario weight includes:

[0068]

[0069] where value i,j V represents the weighted value of the number of times the jth road excitation frequency interval corresponds to the i-th road grade; j represents the user scenario weight corresponding to the j-th road excitation frequency or road excitation frequency interval, which is the cumulative number of excitations in Table 5 in this embodiment.

[0070] The statistics of the number of road excitation frequencies at different road segments are multiplied by the proportion of the corresponding road mileage distribution to obtain the weighted value of the road excitation frequency statistics. The weighted sum of the road excitation frequency statistics for all road levels corresponding to each road excitation frequency segment is then calculated to obtain the cumulative number of excitations, which is the user scenario weight of the road excitation frequency segment. It should be noted that for ease of fitting, the arithmetic midpoint of each road excitation frequency interval is used as the road excitation frequency in subsequent fitting calculations, thereby obtaining a series of data pairs of road excitation frequencies and user scenario weights as shown in Table 5 below: the road excitation frequency in the first column and the cumulative number of excitations in the last column. For example, when the vehicle speed is 30 km / h, the cumulative number of excitations corresponding to the road excitation frequency of 0.5 Hz is 34.0, which corresponds to the value of 30 km / h in Table 3 and the road excitation frequency interval of [0.45, 0.55) × the road mileage proportion of Class 4 roads with an average speed of 30 km / h in Table 4, 0.736, that is, 34.0 × 0.736 ≈ 25.0.

[0071] Table 5

[0072]

[0073]

[0074]

[0075] 1.5. Perform fitting calculations based on each road excitation frequency interval and the corresponding user scenario weight to obtain a fitting relationship between the road excitation frequency and the user scenario weight. The fitting relationship is the first functional relationship between the road excitation frequency and the user scenario.

[0076] In this embodiment, a fitting function is performed based on a data set of a series of road excitation frequencies and cumulative excitation times shown in Table 5 to obtain a fitting function of the road excitation frequency and the user scenario weight (or cumulative excitation times). That is, the cumulative excitation times is the user scenario weight determined based on the road excitation frequency.

[0077] In this embodiment, the first functional relationship y1(f) between the final road excitation frequency and the user scenario is:

[0078] y1(f)=10.606f -2.14

[0079] Where y1(f) represents the user scenario weight, and f represents the road stimulus frequency.

[0080] In the above system, a method for obtaining the second functional relationship y2(f) between the vibration frequency and the amplitude amplification factor of the suspension system includes:

[0081] 2.1. Calculate the corresponding relationship between each set vertical vibration frequency (0.5 Hz to 5 Hz in this embodiment) and the four-channel test bench vibration acceleration based on the set sinusoidal sweep frequency and the set vibration amplitude;

[0082] like Figure 2 The four-channel test bench is shown, and the parameters are set as follows: the sine sweep frequency is set to 0.5Hz-5Hz; the sweep rate is set to 0.05Hz / s (preferably the amplitude +-A = 15mm);

[0083] 2.2. Calculate the corresponding relationship between each set vertical vibration frequency and the four-channel test bench vibration acceleration based on the set sinusoidal sweep frequency and the set vibration amplitude;

[0084] Due to the displacement of the four-channel gantry Where A is the vibration amplitude; ω is the circular frequency of vibration; is the phase of vibration; t is time; take the second derivative of displacement to get the vibration acceleration of the four-channel test bench ω=2πf;

[0085] In this embodiment, the vertical vibration frequency f = 0.5 Hz to 5 Hz; Since the vibration amplitude in the spectrum is expressed as a peak value, the vibration amplitude A needs to be divided by the square root of 2 to convert it into an effective value during calculation;

[0086] The corresponding relationship between the final vertical vibration frequency and the four-channel test bench vibration acceleration a1(f) is: a1(f)=A×ω 2 =A×(2πf) 2 ; a1(f) represents the acceleration of the four-channel rig when the vertical vibration frequency is f.

[0087] The technical effect of the above-mentioned theoretical calculation of the acceleration of the four-channel test bench during vibration is that the measurement of the four-channel vibration can be omitted, and there is no need to arrange acceleration sensors on the four-channel test bench for measurement;

[0088] 2.3. Measure and obtain the corresponding relationship between each set vertical vibration frequency and the vibration acceleration of the vehicle lifting point: a2(f) = H(f);

[0089] 2.4. Calculate the corresponding relationship between each vertical vibration frequency and the four-channel test bench vibration acceleration, and the corresponding relationship between each vertical vibration frequency and the vehicle lifting point vibration acceleration to obtain the second functional relationship y2(f) between the vibration frequency and the amplitude amplification factor of the suspension system.

[0090] The second functional relationship between the vibration frequency and amplitude amplification coefficient of the final suspension system is y2(f) = vehicle lifting point vibration acceleration at frequency f / four-channel test bench vibration acceleration at frequency f, that is: y2(f) = a2(f) / a1(f); according to this formula, the amplitude amplification coefficient corresponding to each vibration frequency can be obtained.

[0091] In certain embodiments, the vibration frequency-vibration comfort evaluation curve represents the corresponding relationship between vibration frequency and vibration comfort, expressed as K1(f) = y1(f) × y2(f). y1(f) represents a first functional relationship between the road excitation frequency and the user scenario; y2(f) represents a second functional relationship between the suspension system's vibration frequency and the amplitude amplification factor. During the calculation process, the road excitation frequency and the suspension system's vibration frequency are uniformly represented as vibration frequency in the curve.

[0092] In some embodiments, a comfort evaluation optimization module is also included: used to obtain a third functional relationship between the vertical vibration frequency and the human perception value; based on the first functional relationship, the second functional relationship and the third functional relationship, an optimized vehicle frequency-vibration comfort evaluation curve is obtained, and the amplitude of the set frequency range in the curve is accumulated to obtain an optimized vehicle low-frequency vertical vibration comfort evaluation index.

[0093] In some embodiments, the third functional relationship y3 is expressed as follows:

[0094]

[0095] Finally, the expression of the optimized vehicle low-frequency vertical vibration comfort curve is K2(f)=y1(f)×y2(f)×y3(f).

[0096] In this embodiment, two vehicles are selected to calculate the comfort evaluation index. The results are shown in Table 6 below. The corresponding optimized vehicle frequency-vibration comfort evaluation curve is shown in Table 6. Figure 3shown.

[0097] Table 6

[0098]

[0099]

[0100] As shown in Table 7 below, the evaluation index of vehicle A is greater than that of vehicle B. The final result is that the comfort of vehicle B is better than that of vehicle A.

[0101] Table 7

[0102]

[0103] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0104] Example 2

[0105] A method for evaluating the comfort of low-frequency vertical vibration of a vehicle, comprising:

[0106] The first functional relationship between the road excitation frequency and the user scenario is obtained based on the vehicle speeds and mileage distribution ratios of various levels of roads;

[0107] The second functional relationship between the vibration frequency and amplitude amplification factor of the suspension system is obtained based on a four-channel endurance test bench;

[0108] Based on the first functional relationship and the second functional relationship, a vibration frequency-vibration comfort evaluation curve is obtained, and the amplitude of a set frequency range in the curve is accumulated to obtain a vehicle low-frequency vertical vibration comfort evaluation index. The comfort index is used to evaluate the low-frequency vertical vibration comfort of the vehicle, and a smaller value indicates better comfort.

[0109] Example 3

[0110] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. The computer program includes program instructions. When the program instructions are executed by a processor, the steps of the method of the present invention are implemented, which will not be described in detail here.

[0111] The computer-readable storage medium may be the data transmission device provided in any of the aforementioned embodiments or an internal storage unit of a computer device, such as a hard disk or memory of the computer device. The computer-readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., provided on the computer device.

[0112] Furthermore, the computer-readable storage medium may include both an internal storage unit of the computer device and an external storage device. The computer-readable storage medium is used to store the computer program and other programs and data required by the computer device. The computer-readable storage medium may also be used to temporarily store data to be output or that has been output.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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 The steps for the function specified in one or more boxes.

[0117] Example 4

[0118] A computer program product includes a computer program / instruction, which implements the steps of the vehicle low-frequency vertical vibration comfort evaluation method when executed by a processor.

[0119] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A vehicle low-frequency vertical vibration comfort evaluation system, characterized in that: include: A user scenario function acquisition module is used to obtain a first functional relationship between road stimulus frequency and user scenario based on vehicle speeds and mileage distribution ratios of various levels of roads; Vehicle suspension vibration transfer function acquisition module: used to obtain the second functional relationship between the vibration frequency and amplitude amplification factor of the suspension system based on a four-channel endurance test bench; Comfort calculation module: used to obtain a vibration frequency-vibration comfort evaluation curve based on the first functional relationship and the second functional relationship, and accumulate the amplitude within a set frequency range in the curve to obtain a vehicle low-frequency vertical vibration comfort evaluation index; In the user scenario function acquisition module, the method for acquiring the first functional relationship includes: Calculate the road excitation frequencies corresponding to various levels of roads based on the road wavelength range; Dividing the road excitation frequency within a set range into multiple intervals to obtain multiple road excitation frequency intervals, and counting the total number of road excitation frequencies belonging to each road excitation frequency interval for each level of road; Obtaining a weighted cumulative value of the number of excitations for each road level in each road excitation frequency interval according to the total number and the mileage distribution ratio of each level of road; Summing up the weighted cumulative values ​​of the number of excitations for each road excitation frequency interval corresponding to each level of road, to obtain the user scenario weight corresponding to each road excitation frequency interval; Perform fitting calculations based on each road excitation frequency interval and the corresponding user scenario weight to obtain a fitting relationship between the road excitation frequency and the user scenario weight. The fitting relationship is the first functional relationship between the road excitation frequency and the user scenario. The method for obtaining the second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system includes: Calculate the corresponding relationship between each set vertical vibration frequency and the four-channel test bench vibration acceleration according to the set sinusoidal sweep frequency and the set vibration amplitude; Measure and obtain the corresponding relationship between each set vertical vibration frequency and the vibration acceleration of the vehicle lifting point; The corresponding relationship between each vertical vibration frequency and the vibration acceleration of the four-channel test bench and the corresponding relationship between each vertical vibration frequency and the vibration acceleration of the vehicle lifting point are calculated to obtain a second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system.

2. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 1, characterized in that: The method for obtaining the weighted cumulative value of the number of excitations for each road excitation frequency interval corresponding to each level of road includes: The weighted cumulative value of the number of road excitations = the total number of road excitation frequency intervals that appear on roads of this level × the mileage distribution ratio of roads of this level.

3. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 1, characterized in that: When performing fitting calculation based on the excitation frequency of each road segment and the corresponding user scenario weight, the method further includes taking the mean or arithmetic midpoint of the excitation frequency of each road segment as the value of the road excitation frequency during fitting.

4. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 1, characterized in that: The second functional relationship between the vibration frequency and the amplitude amplification factor of the suspension system is equal to the corresponding relationship between the vertical vibration frequency and the four-channel test bench vibration acceleration divided by the corresponding relationship between the vertical vibration frequency and the vehicle lifting point vibration acceleration.

5. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 1, characterized in that: It also includes a comfort evaluation optimization module: used to obtain a third functional relationship between the vertical vibration frequency and the human perception value; based on the first functional relationship, the second functional relationship and the third functional relationship, an optimized vehicle frequency-vibration comfort evaluation curve is obtained, and the amplitude of the set frequency range in the curve is accumulated to obtain an optimized vehicle low-frequency vertical vibration comfort evaluation index.

6. A vehicle low-frequency vertical vibration comfort evaluation method according to the system of claim 1, characterized in that: include: The first functional relationship between the road excitation frequency and the user scenario is obtained based on the vehicle speeds and mileage distribution ratios of various levels of roads; The second functional relationship between the vibration frequency and amplitude amplification factor of the suspension system is obtained based on a four-channel endurance test bench; A vibration frequency-vibration comfort evaluation curve is obtained according to the first functional relationship and the second functional relationship, and the amplitude of a set frequency range in the curve is accumulated to obtain a vehicle low-frequency vertical vibration comfort evaluation index.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the vehicle low-frequency vertical vibration comfort evaluation method as claimed in claim 6 are implemented.

8. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the vehicle low-frequency vertical vibration comfort evaluation method described in claim 6 are implemented.

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