Vehicle low-frequency vertical vibration comfort evaluation system and method

Abstract

The invention discloses a vehicle low-frequency vertical vibration comfort evaluation system and method. Comprising the following steps: obtaining a first function relation between a road excitation frequency and a user scene according to vehicle speeds and mileage distribution proportions of various grades of roads; acquiring a second function relation between the vibration frequency and the amplitude amplification coefficient of the suspension system based on the four-channel durable rack; and according to the first function relation between the road excitation frequency and the user scene and the second function relation between the vibration frequency of the suspension system and the amplitude amplification coefficient, a vibration frequency-vibration comfort evaluation curve is obtained, amplitude accumulation is carried out on a set frequency range in the curve, and a vehicle low-frequency vertical vibration comfort evaluation index is obtained. According to the method, the low-frequency vibration comfort level of the vehicle in most user use scenes is evaluated by integrating the road frequency, the vehicle suspension vibration transmission and the human body vibration frequency, and the method is more in line with the actual conditions of users, is more scientific and is more beneficial to guiding the design and development work of the vehicle.

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 bumping sensation transmitted to the vehicle body by the suspension system (springs and shock absorbers) under random road excitation of 0.5-5Hz. If the low-frequency vibration comfort of the vehicle is not designed well, it is easy to make passengers feel motion sickness and vomit. Generally speaking, the low-frequency vibration comfort of the vehicle is determined after the design of the springs and shock absorbers is completed. Therefore, how to optimize the design parameters of the suspension springs and shock absorbers in the early stage of design and improve the low-frequency vibration comfort of the vehicle is one of the key technologies of the OEM.

[0003] One of the existing technologies is the vehicle ride comfort test specified in GBT4970-2009 Automobile Ride Comfort Test Method, which uses the root mean square value of the total weighted acceleration above the seat cushion, the seat back and the foot support surface to evaluate the subjective feeling of human comfort. However, the measurement results of this method are closely related to the quality of the test road and the test vehicle speed, and cannot accurately express the user's usage scenario.

[0004] The second prior art is to measure the vibration transfer characteristics of the vehicle suspension system by frequency sweeping on a vibration test bench, and perform frequency-weighted calculation on the vibration according to the sensitivity of the human body to the vibration frequency, and obtain the root mean square value of acceleration to evaluate the ride comfort of the vehicle. It can accurately evaluate the transmission characteristics of the vehicle suspension system itself to vibration. However, the vehicle is traveling on the road, and it cannot reflect the vibration response of the vehicle when traveling on different roads. Then, by adjusting the stiffness and damping coefficient of the suspension spring, the frequency deviation characteristics and amplitude amplification coefficient of the suspension are optimized. In this way, the ride comfort performance of the vehicle is achieved to meet 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 system and method for evaluating the low-frequency vertical vibration comfort of a vehicle.

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

[0007] User scenario function acquisition module: used to obtain a first functional relationship between road excitation frequency and user scenario according to vehicle speeds of various levels of roads 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] Comfort calculation module: used to obtain a vibration frequency-vibration comfort evaluation curve based on the first functional relationship between the road excitation frequency and the user scenario and the second functional relationship between the vibration frequency and the amplitude magnification factor of the suspension system, and to accumulate the amplitude of the set frequency range in the curve to obtain the 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 the smaller the value, the better the 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 a first functional relationship between the road excitation 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 excitation 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 [v 1 , v 2 , v 3 , ..., v m-1 、v m ], set the road wavelength range to [λ 1 ,λ 2 ,λ 3 , ..., λ n-1 , n ]; the 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 vehicle speed is v 1 The road excitation frequencies corresponding to the roads are v 1 / λ 1 、v 1 / λ 2 ,……,v 1 / λ n-1 、v 1 / λ n ; The vehicle speed is v 2 The road excitation frequencies corresponding to the roads are v 2 / λ 1 、v 2 / λ 2 ,……,v 2 / λ n-1 、v 2 / λn .

[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 ,f 32 ],[f 41 ,f 42 ]……; Count the total number of times each road excitation frequency interval appears on each road as the number of excitations, that is, assuming the vehicle speed is v 1 The road excitation frequencies corresponding to the roads are v 1 / λ 1 、v 1 / λ 2 ,……,v 1 / λ n-1 、v 1 / λ n ; Statistics v 1 / λ 1 、v 1 / λ 2 ,……,v 1 / λ n-1 、v 1 / 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 speed is v 2 The road excitation frequencies corresponding to the roads are v 2 / λ 1 、v 2 / λ 2 ,……,v 2 / λ n-1 、v 2 / λ n The n values ​​in fall into each road excitation frequency interval [f 11 ,f 12 ],[f 21 ,f 22 ],[f 31 ,f32 ],[f 41 ,f 42 ]… and so on, no more details.

[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 of each road excitation frequency interval corresponding to each level of road is obtained; for example: the vehicle speed is v 1 The road corresponds to the set range n 1 The road excitation frequency (f 1 ~f n1 ) falls into the road excitation frequency interval [f 11 ,f 12 ] is N1 times; assuming the vehicle speed is v 1 The mileage of roads is p 1 , then the road excitation frequency interval [f 11 ,f 12 ] corresponds to the vehicle speed v 1 The weighted cumulative value of the number of excitations on the road is equal to N1×p 1 .

[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; an example is as follows: Assuming that the road excitation frequency interval [f 11 ,f 12 ] corresponds to the vehicle speed v 1 The weighted cumulative value of the number of excitations on the road is equal to N1×p 1 ;Road excitation frequency range [f 11 ,f 12 ] corresponds to the vehicle speed v 2 The weighted cumulative value of the number of excitations on the road is equal to N2×p 2 ; Set the road excitation frequency interval [f 11 ,f 12 The weighted cumulative value of the number of excitations for all roads corresponding to ] is summed up to N1×p 1 +N2×p 2 + ... the sum obtained 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 according to 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, and 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 times the road excitation frequency interval appears on roads of this level × the mileage distribution ratio of roads of this level.

[0020] Furthermore, when performing fitting calculation according to the excitation frequency of each road section and the corresponding user scenario weight, it also includes: taking the mean value or arithmetic midpoint of the excitation frequency of each road section 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 frequency statistics corresponding to the jth road excitation frequency interval corresponding 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 magnification 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 sine sweep frequency and the set vibration amplitude;

[0027] The corresponding relationship between each set vertical vibration frequency and the vibration acceleration of the vehicle lifting point is measured;

[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 magnification 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] y 3 (f) is the human perception value; f represents the vertical vibration frequency.

[0036] A vehicle low-frequency vertical vibration comfort evaluation method for achieving the second objective of the present invention comprises:

[0037] According to the vehicle speeds of various levels of roads and the mileage distribution ratios of various levels of roads, a first functional relationship between the road excitation frequency and the user scenario is obtained;

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

[0039] According to the first functional relationship and the second functional relationship, a vibration frequency-vibration comfort evaluation curve is obtained, and the amplitude of the 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 vehicle low-frequency vertical vibration comfort, and the smaller the value, the better the comfort.

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

[0041] The present invention first studies the road mileage level and road level, and summarizes the first functional relationship of the road excitation frequency-user scenario function based on the user vehicle usage scenario, then measures the second functional relationship of the vibration transmission of the vehicle suspension system on a four-channel endurance test bench, and finally analyzes the third functional relationship of the human body to the vibration frequency, and obtains the vehicle low-frequency vertical vibration comfort index that takes into account the road frequency, vehicle suspension vibration transmission, and human body vibration frequency. This index can be used to evaluate the vehicle low-frequency vibration comfort level in most user usage scenarios, which is more in line with the actual user situation, more scientific, and more conducive to guiding the design and development of vehicles. 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 is a schematic diagram of a four-channel bench test according to 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 specific implementations are used to explain the technical solutions of the claims of the present invention so that those skilled in the art can understand the claims. The protection scope of the present invention is not limited to the following specific implementation structures. The technical solutions of the claims of the present invention made by those skilled in the art but different from the following specific implementations are also within the protection scope 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", and the unit is (1 / m). It is the reciprocal of the road wavelength. The road wavelength (λ) represents the minimum distance of the periodically repeated part 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, 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 roads of different 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 used to obtain a first functional relationship between the road excitation frequency and the user scenario according to the vehicle speeds of various levels of roads and the mileage distribution ratios of various levels of roads; the various levels of roads are shown in Table 1, and in this embodiment, the roads are divided into 5 levels;

[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 according to 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 low-frequency vertical vibration comfort evaluation index of the vehicle.

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

[0055] 1.1. Calculate the road excitation frequencies corresponding to various roads according to the road wavelength range; in this embodiment, according to road excitation frequency (Hz) = vehicle speed (m / s) / road wavelength (m); obtain the road excitation frequencies corresponding to various levels of roads under various road wavelengths as shown in Table 2 below. In this embodiment, the vehicle speed is the average vehicle speed under each level of road, and the road wavelength range is 0.1m to 100m; it can be seen that the faster the vehicle speed, the higher the vibration frequency generated under the same road surface roughness; the shorter the road wavelength of 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 of each level of road belonging to each road excitation frequency interval as the number of excitations;

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

[0061] Table 3

[0062]

[0063]

[0064] 1.3. 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; the mileage distribution ratio of each road level is shown in Table 4 below, and the statistical data of this embodiment is the mileage distribution ratio of each road level nationwide;

[0065] Table 4

[0066]

[0067] 1.4. Sum the weighted cumulative values ​​of the number of excitations for each level of road in each road excitation frequency interval to obtain the 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 frequency statistics corresponding to the jth road excitation frequency interval corresponding 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 excitation frequencies of different roads are multiplied by the proportion of the corresponding road mileage distribution to obtain the weighted value of the road excitation frequency statistics; then the weighted sum of the road excitation frequency statistics of all road levels corresponding to each section of the road excitation frequency is calculated to obtain the cumulative value of the number of excitations, which is the user scenario weight of the road excitation frequency; it should be noted that, for the convenience of fitting, the arithmetic midpoint of the excitation frequency interval of each section of the road is used as the road excitation frequency in the subsequent fitting calculation, and then a series of data pairs of road excitation frequencies and user scenario weights are obtained 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 30km / h, the cumulative value of the excitation number when the corresponding road excitation frequency is 0.5Hz is the value corresponding to the vehicle speed of 30km / h and the road excitation frequency interval of [0.45,0.55) in Table 3, 34.0×the road mileage proportion of Class 4 roads with an average speed of 30km / 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 calculation according to 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, wherein the fitting relationship is the first functional relationship between the road excitation frequency and the user scenario;

[0076] In this embodiment, a fitting function of the road excitation frequency and the user scenario weight (or the cumulative value of the number of excitations) is obtained based on a data set of a series of road excitation frequencies and cumulative values ​​of the number of excitations shown in Table 5, that is, the cumulative value of the number of excitations is the user scenario weight determined according to the road excitation frequency.

[0077] In this embodiment, the first functional relationship between the final road excitation frequency and the user scenario is y 1 (f) is:

[0078] y 1 (f) = 10.606f -2.14

[0079] In the formula, y 1 (f) represents the user scenario weight, and f represents the road stimulus frequency.

[0080] In the above system, the second functional relationship y between the vibration frequency and the amplitude magnification factor of the suspension system is obtained: 2The method of (f) comprises:

[0081] 2.1. Calculate the corresponding relationship between each set vertical vibration frequency (0.5 Hz-5 Hz in this embodiment) and the vibration acceleration of the four-channel test bench according to 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 vibration acceleration of the four-channel test bench according to 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; the displacement is secondarily differentiated to obtain the vibration acceleration of the four-channel test bench ω=2πf;

[0085] In this embodiment, the vertical vibration frequency f = 0.5 Hz ~ 5 Hz; Since the vibration amplitude in the spectrum is represented by the 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 vibration acceleration of the four-channel test bench a 1 (f) is: a 1 (f) = A × ω 2 =A×(2πf) 2 ; a 1 (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 an acceleration sensor on the four-channel test bench for measurement;

[0088] 2.3. Measure and obtain the corresponding relationship a between each set vertical vibration frequency and the vibration acceleration of the vehicle lifting point 2 (f) = H(f);

[0089] 2.4. Calculate 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 to obtain the second functional relationship y between the vibration frequency and the amplitude magnification factor of the suspension system 2 (f).

[0090] The second functional relationship between the vibration frequency and amplitude magnification factor of the final suspension system is y 2 (f) = vehicle lifting point vibration acceleration at frequency f / four-channel test bench vibration acceleration at frequency f, that is: y 2 (f) = a 2 (f) / a 1 (f); According to this formula, the amplitude amplification factor corresponding to each vibration frequency can be obtained.

[0091] In some embodiments, the vibration frequency-vibration comfort evaluation curve represents the corresponding relationship between vibration frequency and vibration comfort, and the expression is K 1 (f) = y 1 (f)×y 2 (f);y 1 (f) represents the first functional relationship between the road excitation frequency and the user scenario; y 2 (f) represents the second functional relationship between the vibration frequency of the suspension system and the amplitude magnification factor. During the calculation process, the road excitation frequency and the vibration frequency of the suspension system are uniformly represented as the 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; 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.

[0093] In some embodiments, the third functional relationship y 3 The expression is as follows:

[0094]

[0095] Finally, the expression of the optimized vehicle low-frequency vertical vibration comfort curve K 2 (f) = y 1 (f)×y 2 (f)×y 3 (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 as follows: Figure 3 shown.

[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, and 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 order of execution of the steps in the above embodiment does not necessarily 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 embodiment of the present invention.

[0104] Example 2

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

[0106] According to the vehicle speeds of various levels of roads and the mileage distribution ratios of various levels of roads, a first functional relationship between the road excitation frequency and the user scenario is obtained;

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

[0108] According to the first functional relationship and the second functional relationship, a vibration frequency-vibration comfort evaluation curve is obtained, and the amplitude of the 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 vehicle low-frequency vertical vibration comfort, and the smaller the value, the better the comfort.

[0109] Example 3

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

[0111] The computer-readable storage medium may be the data transmission device provided in any of the aforementioned embodiments or the internal storage unit of the computer device, such as the 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 memory card (smartmedia card, SMC), a secure digital (secure digital, SD) card, a flash card (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 has been output.

[0113] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, 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 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 flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, 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 flowchart and / or block diagram. 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 capable of directing a computer or other programmable data processing device to operate 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 A 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 operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0117] Example 4

[0118] A computer program product comprises a computer program / instruction, wherein when the computer program / instruction is executed by a processor, the steps of the vehicle low-frequency vertical vibration comfort evaluation method are implemented.

[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: User scenario function acquisition module: used to obtain a first functional relationship between road excitation frequency and user scenario according to vehicle speeds of various levels of roads 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 according to the first functional relationship and the second functional relationship, accumulate the amplitude of a set frequency range in the curve, and obtain a vehicle low-frequency vertical vibration comfort evaluation index.

2. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 1, characterized in that: 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 according to 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 of each grade of road belonging to each road excitation frequency interval; According to the total number and the mileage distribution ratio of each level of roads, a weighted cumulative value of the number of excitations for each road excitation frequency interval corresponding to each level of roads is obtained; The weighted cumulative values ​​of the number of excitations for each road level corresponding to each road excitation frequency interval are summed to obtain the user scenario weight corresponding to each road excitation frequency interval; A fitting calculation is performed according to 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, and the fitting relationship is the first functional relationship between the road excitation frequency and the user scenario.

3. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 2, 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 excitation times = the total number of times the road excitation frequency interval appears on roads of this level × the mileage distribution ratio of roads of this level.

4. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 2, characterized in that: When performing fitting calculation according to the excitation frequency of each road section and the corresponding user scenario weight, it also includes: taking the mean value or arithmetic midpoint of the excitation frequency of each road section as the value of the road excitation frequency during fitting.

5. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 1, characterized in that: The method for obtaining the second functional relationship between the vibration frequency and the amplitude magnification 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 sine sweep frequency and the set vibration amplitude; The corresponding relationship between each set vertical vibration frequency and the vibration acceleration of the vehicle lifting point is measured; 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.

6. The vehicle low-frequency vertical vibration comfort evaluation system according to claim 5, characterized in that: The second functional relationship between the vibration frequency and the amplitude magnification factor of the suspension system is equal to the corresponding relationship between the vertical vibration frequency and the vibration acceleration of the four-channel test bench divided by the corresponding relationship between the vertical vibration frequency and the vibration acceleration of the vehicle lifting point.

7. 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; 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.

8. A method for evaluating the comfort of low-frequency vertical vibration of a vehicle, characterized in that: include: According to the vehicle speeds of various levels of roads and the mileage distribution ratios of various levels of roads, a first functional relationship between the road excitation frequency and the user scenario is obtained; The second functional relationship between the vibration frequency and the amplitude magnification factor of the suspension system is obtained based on a four-channel endurance test bench; According to 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.

9. 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 8 are implemented.

10. 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 8 are implemented.

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