Method, device, equipment and storage medium for indirectly testing leaf spring stiffness

Abstract

The present invention discloses a method, device, equipment, and storage medium for indirectly testing the stiffness of a leaf spring, relating to the field of leaf spring testing technology. The method includes installing acceleration sensors above and below the leaf spring to be tested, and driving all wheels of the vehicle to drop simultaneously from a platform of the same style; fitting the free vibration attenuation curve of the sprung object based on the relative acceleration between the accelerations recorded by the two acceleration sensors; and obtaining the stiffness of the leaf spring to be tested based on the time interval between the first and second times the leaf spring is in a compressed state in the free vibration attenuation curve of the sprung object, as well as the sprung mass of the leaf spring to be tested. The present application links the stiffness of the leaf spring in a dynamic state of the entire vehicle with the stiffness of the leaf spring in a static state of the entire vehicle. By measuring under the conditions of the entire vehicle, the theoretical stiffness of the leaf spring can be measured without disassembling the leaf spring, thereby reducing labor and disassembly time.

Description

Technical Field

[0001] The present application relates to the field of leaf spring testing technology, and in particular to a method, device, equipment and storage medium for indirectly testing the stiffness of a leaf spring. Background Art

[0002] At present, the mainstream elastic element of commercial vehicle suspension is leaf spring. The stiffness of leaf spring affects the ride and handling performance of the whole vehicle. The stiffness of leaf spring is an important parameter in the development of suspension and whole vehicle. The existing leaf spring stiffness test method is to obtain it through bench testing of single product. It is applicable in forward development and is suitable for obtaining the theoretical stiffness value of leaf spring. However, there are the following problems: (1) Bench testing is time-consuming and labor-intensive and often difficult to implement in reverse development; (2) Although bench testing can accurately represent the stiffness of a single product, it cannot show its actual stiffness on the whole vehicle.

[0003] It can be seen that the existing leaf spring test analysis still focuses on the stiffness of a single leaf spring, and has the inherent disadvantage of not being able to fully characterize the stiffness of the entire vehicle, that is, it does not link the stiffness of a single leaf spring with the leaf spring under the entire vehicle. Summary of the Invention

[0004] The present application provides a method, device, equipment and storage medium for indirectly testing the stiffness of a leaf spring, which links the stiffness of the leaf spring in the dynamic state of the whole vehicle with the stiffness of the leaf spring in the static state of the whole vehicle. By measuring under the conditions of the whole vehicle, the theoretical stiffness of the leaf spring can be measured without disassembling the leaf spring, thereby reducing labor and disassembly time.

[0005] In a first aspect, an embodiment of the present application provides a method for indirectly testing the stiffness of a leaf spring, the method comprising:

[0006] Acceleration sensors are placed above and below the leaf spring to be tested, and all wheels of the vehicle are driven to fall from the same type of platform at the same time;

[0007] Based on the relative acceleration recorded by the two acceleration sensors, the free vibration attenuation curve of the sprung object is fitted;

[0008] The stiffness of the leaf spring to be tested is obtained based on the time intervals between the first and second times the leaf spring is in the compression state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested.

[0009] In combination with the first aspect, in one embodiment, the acceleration sensors are provided above and below the leaf spring to be tested, specifically including:

[0010] An acceleration sensor is arranged on the vehicle frame above the leaf spring to be tested, and an acceleration sensor is arranged below the leaf spring to be tested;

[0011] A platform of the same style is placed in front of each axle of the vehicle, and the platform is a wedge-shaped convex block structure.

[0012] In combination with the first aspect, in one embodiment, driving all wheels of the vehicle to fall from the same type of platform simultaneously specifically includes:

[0013] Drive the vehicle's wheels onto the platform, brake the vehicle, put it in neutral, and stop the power;

[0014] Release the brakes of the vehicle, and the vehicle moves along the upper surface of the platform under the action of gravity, and all the wheels of the vehicle fall off the platform at the same time;

[0015] The acceleration sensors above and below the leaf spring to be tested record the acceleration data from the start of the fall to the stop of the vehicle.

[0016] In conjunction with the first aspect, in one embodiment, fitting the free vibration attenuation curve of the sprung object based on the relative acceleration recorded by the two acceleration sensors specifically includes:

[0017] Calculating the relative acceleration between the acceleration recorded by the acceleration sensor above the leaf spring to be tested and the acceleration recorded by the acceleration sensor below the leaf spring to be tested;

[0018] The relative acceleration is low-pass filtered based on a set cutoff frequency, and a curve fitting between acceleration and time is performed based on the relative acceleration after the low-pass filtering to obtain a free vibration attenuation curve of the sprung object.

[0019] In conjunction with the first aspect, in one embodiment, obtaining the stiffness of the leaf spring to be tested based on the time intervals between the first and second times the leaf spring is in the compressed state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested specifically includes:

[0020] Obtaining the time interval between the first time the leaf spring is in a compressed state and the second time the leaf spring is in a compressed state in a free vibration attenuation curve of the sprung object;

[0021] A frequency is obtained based on the time interval, and the stiffness of the leaf spring to be tested is calculated according to the frequency and the sprung mass of the leaf spring to be tested.

[0022] In conjunction with the first aspect, in one embodiment, calculating the stiffness of the leaf spring to be tested specifically includes:

[0023]

[0024] Among them, C represents the stiffness of the leaf spring to be tested, that is, the stiffness of the leaf spring under the dynamic state of the whole vehicle, f represents the frequency, T represents the time interval between the first compression state and the second compression state of the leaf spring in the free vibration attenuation curve of the sprung object, and P represents the sprung mass of the leaf spring to be tested.

[0025] In conjunction with the first aspect, in one embodiment, the stiffness of the leaf spring to be tested in the static state of the vehicle is calculated as follows:

[0026]

[0027] Where C1 represents the stiffness of the leaf spring to be tested when the vehicle is at rest, and k represents the adjustment coefficient, which is calculated based on the stiffness of the leaf spring of a similar vehicle in both the static and dynamic states.

[0028] In a second aspect, an embodiment of the present application provides a device for indirectly testing the stiffness of a leaf spring, the device comprising:

[0029] A setting module is used to set acceleration sensors above and below the leaf spring to be tested, and drive all wheels of the vehicle to fall from the same type of platform at the same time;

[0030] a fitting module for fitting a free vibration attenuation curve of the sprung object based on the relative acceleration between the accelerations recorded by the two acceleration sensors;

[0031] The execution module is used to obtain the stiffness of the leaf spring to be tested according to the time intervals between the first and second times when the leaf spring is in the compression state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested.

[0032] In a third aspect, an embodiment of the present application provides a device for indirectly testing the stiffness of a leaf spring, wherein the device for indirectly testing the stiffness of a leaf spring comprises a processor, a memory, and a program for indirectly testing the stiffness of a leaf spring stored in the memory and executable by the processor, wherein when the program for indirectly testing the stiffness of a leaf spring is executed by the processor, the steps of the method for indirectly testing the stiffness of a leaf spring described above are implemented.

[0033] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which is stored a program for indirectly testing the stiffness of a leaf spring. When the program for indirectly testing the stiffness of a leaf spring is executed by a processor, the steps of the above-mentioned method for indirectly testing the stiffness of a leaf spring are implemented.

[0034] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0035] By linking the leaf spring stiffness of the entire vehicle in a dynamic state with the leaf spring stiffness of the entire vehicle in a static state, and measuring it under the conditions of the entire vehicle, the theoretical stiffness of the leaf spring can be measured without disassembling the leaf spring, thus reducing labor and disassembly time. This has certain guiding significance for the development of leaf springs, suspensions, and even entire vehicles, and there is no need to increase the number of subsequent tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic flow chart of the method for indirectly testing the stiffness of a leaf spring according to the present application;

[0037] Figure 2 It is a structural diagram of the platform;

[0038] Figure 3 It is a schematic diagram of the free vibration attenuation curve of the leaf spring;

[0039] Figure 4 Schematic diagram of the functional modules of the device for indirectly testing the stiffness of a leaf spring in this application;

[0040] Figure 5 Schematic diagram of the hardware structure of the device for indirectly testing the stiffness of leaf springs in this application. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0043] On the first aspect, the embodiments of the present application provide a method for indirectly testing the stiffness of a leaf spring. By measuring under the conditions of a whole vehicle, the stiffness of the leaf spring can be measured without disassembling the leaf spring, thereby reducing labor and disassembly time. The theoretical stiffness value of the leaf spring can be indirectly obtained through the stiffness value under the whole vehicle, that is, the stiffness value under the whole vehicle (complex coupling system) and the corresponding theoretical stiffness value (the stiffness value calculated by the leaf spring theory or the leaf spring stiffness test value under a single-body test bench) are obtained at the same time, which has certain guiding significance for the development of leaf springs, suspensions and even whole vehicles.

[0044] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the method for indirectly testing the leaf spring stiffness in this application. Figure 1As shown, the indirect methods for testing leaf spring stiffness include:

[0045] S1: Acceleration sensors are installed above and below the leaf spring to be tested, and all wheels of the vehicle are driven to fall from the same type of platform at the same time;

[0046] S2: Based on the relative acceleration between the accelerations recorded by the two accelerometers, the free vibration attenuation curve of the sprung object is fitted;

[0047] S3: Obtaining the stiffness of the leaf spring to be tested based on the time intervals between the first and second times the leaf spring is in the compression state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested.

[0048] Furthermore, in one embodiment, acceleration sensors are provided above and below the leaf spring to be tested, specifically including:

[0049] S101: installing an acceleration sensor on the vehicle frame above the leaf spring to be tested, and installing an acceleration sensor below the leaf spring to be tested;

[0050] Specifically, for the axle where the leaf spring to be tested is located, an acceleration sensor is installed at a corresponding position on the frame above it, and an acceleration sensor is also installed at a corresponding position below it (such as on the axle or the rim).

[0051] S102: A platform of the same type is placed in front of each axle of the vehicle, wherein the platform is a wedge-shaped convex block structure.

[0052] For the specific structure of the platform, see Figure 2 As shown, it is a rigid, hard wedge-shaped protrusion or other similar device (such as hardwood). The height H of the platform is 80mm~85mm, and the lateral width of the platform should ensure that all the wheels of a single axle can be placed on it. At the same time, the top surface of the platform has a certain angle, so that the wheels of the vehicle can move on the top surface of the platform and fall from the platform under the action of gravity.

[0053] For example, a vehicle includes two axles, namely a front axle and a rear axle. It is necessary to place a platform in front of the front axle and a platform in front of the rear axle. During subsequent testing, all wheels of the front axle are driven onto the platform in front of it, and all wheels of the front axle are also driven onto the platform in front of it.

[0054] Furthermore, in one embodiment, driving all wheels of the vehicle to fall from the same type of platform simultaneously includes:

[0055] S111: driving the wheels of the vehicle onto the platform, braking the vehicle, shifting the vehicle into neutral, and stopping the power;

[0056] Specifically, the wheels of each axle of the vehicle to be tested are driven onto the platform, and then the vehicle is braked, shifted into neutral, and the engine (or motor) is stopped. It should be noted that in order to ensure that multiple axles fall simultaneously and reduce the frequency deviation measurement error caused by the coupling of multiple systems in the vehicle, the wheels of all axles must be stopped on the platform;

[0057] S112: releasing the brakes of the vehicle, causing the vehicle to move along the upper surface of the platform under the action of gravity, and all wheels of the vehicle to fall off the platform simultaneously;

[0058] S113: The acceleration sensors above and below the leaf spring to be tested record acceleration data from the start of the fall to the stop of the vehicle.

[0059] Specifically, after the vehicle brakes are released, the vehicle moves along the upper surface of the platform under the action of gravity, and all the wheels of the vehicle fall from the platform at the same time. When the wheels officially fall from the platform, the acceleration sensor starts to record acceleration data. When the vehicle stops, the acceleration sensor stops recording acceleration data.

[0060] Furthermore, in one embodiment, fitting a free vibration attenuation curve of the sprung object based on the relative acceleration recorded by the two acceleration sensors specifically includes:

[0061] S201: Calculating the relative acceleration between the acceleration recorded by the acceleration sensor above the leaf spring to be tested and the acceleration recorded by the acceleration sensor below the leaf spring to be tested;

[0062] S202: Low-pass filtering the relative acceleration based on a set cutoff frequency, and fitting an acceleration-time curve based on the low-pass filtered relative acceleration to obtain a free vibration attenuation curve of the sprung object.

[0063] Specifically, a computer is used to calculate the relative acceleration between the accelerations recorded by the two accelerometers at the leaf spring under test. This relative acceleration is then low-pass filtered with a cutoff frequency of 5 Hz. The free vibration attenuation curve of the sprung object is then fitted. This curve should be complete and free of anomalies. The sprung object is the object supported by the leaf spring.

[0064] Furthermore, in one embodiment, the stiffness of the leaf spring to be tested is obtained based on the time interval between the first and second times the leaf spring is in the compressed state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested, specifically including:

[0065] S301: Obtaining, in a free vibration attenuation curve of a sprung object, a time interval between when a leaf spring is in a compressed state for the first time and when the leaf spring is in a compressed state for the second time;

[0066] By reading the time when the leaf spring is in the compression state for the first time and the time when the leaf spring is in the compression state for the second time in the free vibration attenuation curve of the sprung object, the time interval between the two times is obtained;

[0067] S302: Obtain a frequency based on the time interval, and calculate the stiffness of the leaf spring to be tested according to the frequency and the sprung mass of the leaf spring to be tested.

[0068] In this application, the calculation of the leaf spring stiffness to be tested specifically includes:

[0069]

[0070] Where, C represents the stiffness of the leaf spring to be tested. The stiffness C calculated at this time is the leaf spring stiffness of the vehicle in a dynamic state (i.e., the test stiffness), and f represents the frequency. T represents the time interval between the first and second compression states of the leaf spring in the free vibration attenuation curve of the sprung object, and P represents the sprung mass of the leaf spring under test, i.e., the mass of the sprung object.

[0071] Furthermore, the stiffness of the leaf spring to be tested in the static state of the vehicle is calculated as follows:

[0072]

[0073] Among them, C1 represents the stiffness of the leaf spring to be tested in the static state of the vehicle, that is, the theoretical stiffness of the leaf spring (i.e., static stiffness); k represents the adjustment coefficient, which is calculated based on the leaf spring stiffness of the vehicle in the static state and the leaf spring stiffness of the vehicle in the dynamic state of a similar vehicle model. Specifically, the adjustment coefficient k can be obtained by calculating the ratio between the static stiffness of a similar vehicle model (same number of axles, same series) and the test stiffness, and the adjustment coefficient k is a fixed value.

[0074] The following is a detailed description of the implementation principle of the method for indirectly testing the leaf spring stiffness described in this application.

[0075] Regarding the sensor setup, an acceleration sensor is placed on the vehicle's upper suspension (above the suspension, for example, directly above the corresponding axle), and an acceleration sensor is placed on the vehicle's lower suspension (below the suspension). Regarding the setup of the platform (or test device), its structural style is as follows: Figure 2 As shown, it is a rigid, hard wedge-shaped protrusion or other similar device (such as hardwood). The height H of the platform is 80mm~85mm. A platform is arranged in front of each axle, and the lateral width of the platform should ensure that all the wheels of a single axle can be placed on it.

[0076] Drive the vehicle's wheels onto the platform, brake the vehicle, shift it into neutral, stop the power, release the brakes, and the vehicle moves along the upper surface of the platform under the action of gravity. All the vehicle's wheels fall from the platform at the same time, and the rear ends of the wheels touch the platform after they start to fall. The acceleration sensor records the acceleration data from the start of the fall to the vehicle coming to a standstill.

[0077] Of course, in actual applications, in addition to the above-mentioned rolling method, the vehicle's free vibration attenuation method can also adopt the dropping method, the pulling-down method, etc., but it is necessary to ensure that all axles fall at the same time.

[0078] The following analysis shows that when a vehicle falls from a hardwood (or other rigid device), its motion can be approximated as a free-damping vibration, and the displacement x of its motion can be expressed as:

[0079]

[0080] Since displacement is not easy to measure during the test, the acceleration expression is derived by taking the second-order derivative, which is:

[0081]

[0082] Where a represents acceleration, which is the second derivative of x, ω d , ω represents the intermediate quantity, ξ represents the damping ratio, represents the initial phase, γ represents the intermediate quantity, γ=sin -1 ξ is used to represent the phase change caused by the derivation process, C represents the stiffness of the vibration system (for this application, that is, the stiffness of the leaf spring in the suspension), and m represents the mass of the vibrating object (for the vehicle system of this application, that is, the mass of the sprung object).

[0083] The free vibration attenuation curve of a sprung object is as follows: Figure 3 As shown, the abscissa represents time t, the ordinate represents acceleration a, A1 represents the peak value when the leaf spring is in compression for the first time in the free vibration attenuation curve, A2 represents the peak value when the leaf spring is in compression for the second time in the free vibration attenuation curve, and T represents the time interval when the leaf spring is in compression for the first time and when the leaf spring is in compression for the second time in the free vibration attenuation curve.

[0084] The following conclusions can be drawn from the above theory:

[0085] 1.ω d It can be indirectly obtained by measuring the time interval T when the leaf spring is in the compression state for the first time and the second time in the free vibration attenuation curve, that is,

[0086] 2. The damping ratio can also be obtained indirectly by measuring the size of A1 and A2 in the curve, that is,

[0087] 3. Then we can get In the approximate case (ignoring the damping size), ω d ≈ω(The following derivations are based on ω d ≈ω proceed).

[0088] On the other hand, according to the suspension theory, ω is further deduced:

[0089]

[0090] Therefore, the final frequency Wherein, P represents the gravity of the vibrating object (for the present application, that is, the sprung mass of the leaf spring, that is, the mass of the sprung object), and g represents the acceleration due to gravity.

[0091] Based on the above analysis, the magnitude of the frequency f can be obtained, that is, The size of the test stage, that is, It should be noted that this test stiffness is considered to be the stiffness of the vehicle under dynamic conditions, which is different from the static stiffness C during forward development. 静 There are differences. In order to further obtain the static stiffness, it can be indirectly obtained through the static stiffness and test stiffness of existing similar models. The ratio between the test stiffness and static stiffness of existing similar models is approximately equal to the ratio between the test stiffness and static stiffness of the current vehicle to be tested. After data accumulation, the ratio between the test stiffness and static stiffness of different models is a known value, which can be recorded as k. In summary, the theoretical stiffness (static stiffness) of the leaf spring can be obtained, that is, Among them, C1 is C 静 .

[0092] In order to obtain the value of k under different strains, a certain amount of sample and quantity accumulation is needed in the early stage, and the values ​​of k corresponding to different strains and different numbers of axes are accumulated. Without loss of generality, it is recommended to accumulate 2 to 3 sample data for each subcategory, and take the average value to record as the size of k.

[0093] The method for indirectly testing the stiffness of a leaf spring in an embodiment of the present application links the stiffness of a leaf spring in a dynamic state of the entire vehicle with the stiffness of a leaf spring in a static state of the entire vehicle. By measuring under the conditions of the entire vehicle, the theoretical stiffness of the leaf spring can be measured without disassembling the leaf spring, thereby reducing labor and disassembly time. This method has certain guiding significance for the development of leaf springs, suspensions, and even entire vehicles, and there is no need to increase the number of additional tests subsequently.

[0094] In a second aspect, an embodiment of the present application also provides a device for indirectly testing the stiffness of a leaf spring.

[0095] In one embodiment, referring to Figure 4 , Figure 4 This is a functional module diagram of the device for indirectly testing the leaf spring stiffness in this application. Figure 4 As shown, the device for indirectly testing the stiffness of a leaf spring includes: a setting module, a fitting module, and an execution module.

[0096] The setup module is used to place acceleration sensors above and below the leaf spring to be tested, and drive all wheels of the vehicle to drop simultaneously from the same type of platform; the fitting module is used to fit the free vibration attenuation curve of the sprung object based on the relative acceleration between the accelerations recorded by the two acceleration sensors; and the execution module is used to obtain the stiffness of the leaf spring to be tested based on the time interval between the first and second times the leaf spring is in the compression state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested.

[0097] In this application, the acceleration sensors are provided above and below the leaf spring to be tested, specifically including:

[0098] An acceleration sensor is arranged on the vehicle frame above the leaf spring to be tested, and an acceleration sensor is arranged below the leaf spring to be tested;

[0099] A platform of the same style is placed in front of each axle of the vehicle, and the platform is a wedge-shaped convex block structure.

[0100] In the present application, the method of driving all wheels of the vehicle to fall from the same style platform at the same time specifically includes:

[0101] Drive the vehicle's wheels onto the platform, brake the vehicle, put it in neutral, and stop the power;

[0102] Release the brakes of the vehicle, and the vehicle moves along the upper surface of the platform under the action of gravity, and all the wheels of the vehicle fall off the platform at the same time;

[0103] The acceleration sensors above and below the leaf spring to be tested record the acceleration data from the start of the fall to the stop of the vehicle.

[0104] In this application, the free vibration attenuation curve of the sprung object is obtained by fitting the relative acceleration between the accelerations recorded by the two acceleration sensors, which specifically includes:

[0105] Calculating the relative acceleration between the acceleration recorded by the acceleration sensor above the leaf spring to be tested and the acceleration recorded by the acceleration sensor below the leaf spring to be tested;

[0106] The relative acceleration is low-pass filtered based on a set cutoff frequency, and a curve fitting between acceleration and time is performed based on the relative acceleration after the low-pass filtering to obtain a free vibration attenuation curve of the sprung object.

[0107] In the present application, obtaining the stiffness of the leaf spring to be tested based on the time intervals between the first and second times the leaf spring is in the compressed state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested specifically includes:

[0108] Obtaining the time interval between the first time the leaf spring is in a compressed state and the second time the leaf spring is in a compressed state in a free vibration attenuation curve of the sprung object;

[0109] A frequency is obtained based on the time interval, and the stiffness of the leaf spring to be tested is calculated according to the frequency and the sprung mass of the leaf spring to be tested.

[0110] In a third aspect, an embodiment of the present application provides a device for indirectly testing the stiffness of a leaf spring. The device for indirectly testing the stiffness of a leaf spring may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0111] Reference Figure 5 , Figure 5 Schematic diagram of the hardware structure of the device for indirectly testing the stiffness of a leaf spring involved in the embodiment of the present application. In the embodiment of the present application, the device for indirectly testing the stiffness of a leaf spring may include a processor, a memory, a communication interface, and a communication bus.

[0112] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0113] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the indirect leaf spring stiffness testing device, as well as interfaces used to interconnect the indirect leaf spring stiffness testing device with other devices (e.g., other computing devices or user devices). Physical interfaces can include Ethernet, fiber optic, or ATM interfaces; user devices can include displays, keyboards, and other devices.

[0114] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0115] The processor may be a general-purpose processor that can call a program for indirectly testing the leaf spring stiffness stored in a memory and execute the method for indirectly testing the leaf spring stiffness provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the program for indirectly testing the leaf spring stiffness is called can be referenced to the various embodiments of the method for indirectly testing the leaf spring stiffness provided in the present application and will not be further described here.

[0116] Those skilled in the art will understand that Figure 5 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0117] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0118] The computer-readable storage medium of the present application stores a program for indirectly testing the stiffness of a leaf spring, wherein when the program for indirectly testing the stiffness of a leaf spring is executed by a processor, the steps of the method for indirectly testing the stiffness of a leaf spring as described above are implemented.

[0119] Among them, the method implemented when the program for indirectly testing the stiffness of the leaf spring is executed can refer to the various embodiments of the method for indirectly testing the stiffness of the leaf spring in this application, and will not be repeated here.

[0120] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0121] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0122] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0123] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0124] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0125] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for indirectly testing the stiffness of a leaf spring, characterized in that: The method for indirectly testing the leaf spring stiffness includes: Acceleration sensors are placed above and below the leaf spring to be tested, and all wheels of the vehicle are driven to fall from the same type of platform at the same time; Based on the relative acceleration recorded by the two acceleration sensors, the free vibration attenuation curve of the sprung object is fitted; The stiffness of the leaf spring to be tested is obtained based on the time interval between the first and second times the leaf spring is in the compression state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested.

2. A method for indirectly testing leaf spring stiffness according to claim 1, characterized in that: The acceleration sensors are arranged above and below the leaf spring to be tested, specifically comprising: An acceleration sensor is arranged on the vehicle frame above the leaf spring to be tested, and an acceleration sensor is arranged below the leaf spring to be tested; A platform of the same style is placed in front of each axle of the vehicle, and the platform is a wedge-shaped convex block structure.

3. A method for indirectly testing leaf spring stiffness according to claim 2, characterized in that: The method of causing all wheels of the vehicle to fall simultaneously from the same type of platform specifically includes: Drive the vehicle's wheels onto the platform, brake the vehicle, put it in neutral, and stop the power; Release the brakes of the vehicle, and the vehicle moves along the upper surface of the platform under the action of gravity, and all the wheels of the vehicle fall off the platform at the same time; The acceleration sensors above and below the leaf spring to be tested record the acceleration data from the start of the fall to the stop of the vehicle.

4. A method for indirectly testing leaf spring stiffness according to claim 1, characterized in that: The fitting of the free vibration attenuation curve of the sprung object based on the relative acceleration between the accelerations recorded by the two acceleration sensors specifically includes: Calculating the relative acceleration between the acceleration recorded by the acceleration sensor above the leaf spring to be tested and the acceleration recorded by the acceleration sensor below the leaf spring to be tested; The relative acceleration is low-pass filtered based on a set cutoff frequency, and a curve fitting between acceleration and time is performed based on the relative acceleration after the low-pass filtering to obtain a free vibration attenuation curve of the sprung object.

5. The method for indirectly testing the stiffness of a leaf spring according to claim 1, wherein: Obtaining the stiffness of the leaf spring to be tested based on the time intervals between the first and second times the leaf spring is in the compressed state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested specifically includes: Obtaining the time interval between the first time the leaf spring is in a compressed state and the second time the leaf spring is in a compressed state in a free vibration attenuation curve of the sprung object; A frequency is obtained based on the time interval, and the stiffness of the leaf spring to be tested is calculated according to the frequency and the sprung mass of the leaf spring to be tested.

6. A method for indirectly testing leaf spring stiffness according to claim 5, characterized in that: The calculation of the leaf spring stiffness to be tested includes: Among them, C represents the stiffness of the leaf spring to be tested, that is, the stiffness of the leaf spring under the dynamic state of the whole vehicle, f represents the frequency, T represents the time interval between the first compression state and the second compression state of the leaf spring in the free vibration attenuation curve of the sprung object, and P represents the sprung mass of the leaf spring to be tested.

7. A method for indirectly testing leaf spring stiffness according to claim 6, characterized in that: The stiffness of the leaf spring to be tested in the static state of the vehicle is calculated as follows: Where C1 represents the stiffness of the leaf spring to be tested when the vehicle is at rest, and k represents the adjustment coefficient, which is calculated based on the stiffness of the leaf spring of a similar vehicle in both the static and dynamic states.

8. A device for indirectly testing the stiffness of a leaf spring, characterized in that: The device for indirectly testing the leaf spring stiffness comprises: A setting module is used to set acceleration sensors above and below the leaf spring to be tested, and drive all wheels of the vehicle to fall from the same type of platform at the same time; a fitting module for fitting a free vibration attenuation curve of the sprung object based on the relative acceleration between the accelerations recorded by the two acceleration sensors; The execution module is used to obtain the stiffness of the leaf spring to be tested according to the time intervals between the first and second times when the leaf spring is in the compression state in the free vibration attenuation curve of the sprung object and the sprung mass of the leaf spring to be tested.

9. A device for indirectly testing the stiffness of a leaf spring, characterized in that: The device for indirectly testing the stiffness of a leaf spring includes a processor, a memory, and a program for indirectly testing the stiffness of a leaf spring stored in the memory and executable by the processor, wherein when the program for indirectly testing the stiffness of a leaf spring is executed by the processor, the steps of the method for indirectly testing the stiffness of a leaf spring as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program for indirectly testing the stiffness of a leaf spring, wherein when the program for indirectly testing the stiffness of a leaf spring is executed by a processor, the steps of the method for indirectly testing the stiffness of a leaf spring according to any one of claims 1 to 7 are implemented.

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