Method, device and related equipment for measuring moment of inertia of sprung mass of tractor

Abstract

The present application relates to the technical field of vehicle testing, and particularly to a method and device for measuring the moment of inertia of the sprung mass of a tractor, and related equipment; the method is applied to a tractor, a balanced suspension is provided on the tractor, and the sprung mass of the tractor can perform pitching vibration around the suspension spindle of the balanced suspension; the method includes: determining the leaf spring stiffness of the leaf springs on the tractor by moving the cab of the tractor; determining the vibration frequency of the sprung mass by vibrating the cab; wherein, the vibration frequency of the sprung mass is the degree of vibration when the sprung mass rotates around the axis of the balanced suspension spindle; determining the moment of inertia of the sprung mass of the tractor according to the leaf spring stiffness and the vibration frequency; the present application can solve the technical problem that the existing estimation method for the moment of inertia has a large error in the prior art.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle testing, and particularly relates to a method, device and related equipment for measuring the moment of inertia of the sprung mass of a tractor. Background Art

[0002] In the process of designing and evaluating the performance of a towing vehicle (truck), it is necessary to determine the moment of inertia of the sprung mass of the loaded vehicle about the axis of the balance suspension spindle through experimental measurement or numerical simulation. Among them, the sprung mass generally refers to the sum of parts including the frame, body, engine, transmission system, as well as passengers and cargo in the loaded vehicle. The moment of inertia is a measure of the difficulty for the loaded vehicle to resist changing its rotational state.

[0003] In the existing technical solutions for measuring the moment of inertia of the sprung mass of a loaded vehicle about the axis of the balance suspension spindle, it is usually measured by the simulation method, that is, by fixing the sprung mass at one end of a torsion pendulum and making it freely rotate about the axis of the balance suspension spindle, and then measuring the period of the torsion pendulum. According to the period of the torsion pendulum and the relevant parameters of the torsion pendulum device (such as the moment of inertia of the torsion pendulum, the sprung mass, the length of the torsion pendulum, etc.), the moment of inertia of the sprung mass is approximately estimated.

[0004] According to actual experience, it can be known that the above-mentioned estimation method for the moment of inertia has the disadvantage of large errors. Summary of the Invention

[0005] In view of this, the purpose of the present application is to provide a method, device and related equipment for measuring the moment of inertia of the sprung mass of a tractor, so as to solve the technical problem that the existing estimation method for the moment of inertia has the disadvantage of large errors.

[0006] In a first aspect, the present application provides a method for measuring the moment of inertia of the sprung mass of a tractor, which is applied to a tractor. A balance suspension is provided on the tractor, and the sprung mass of the tractor can perform pitching vibration around the suspension spindle of the balance suspension. The method includes:

[0007] Determine the leaf spring stiffness of the leaf springs on the tractor by moving the cab of the tractor.

[0008] Determine the vibration frequency of the sprung mass by vibrating the cab.

[0009] Wherein, the vibration frequency of the sprung mass is the degree of vibration when the sprung mass rotates around the axis of the balance suspension spindle.

[0010] Determine the moment of inertia of the sprung mass of the tractor according to the leaf spring stiffness and the vibration frequency.

[0011] Second aspect, the present application provides a device for measuring the moment of inertia of the suspended mass of a tractor, which is applied to a tractor. A balance suspension is provided on the tractor, and the suspended mass of the tractor can perform pitching vibration around the suspension spindle of the balance suspension; the device includes: a stiffness measurement module, a frequency measurement module, and an inertia measurement module;

[0012] The stiffness measurement module is used to determine the leaf spring stiffness of the leaf spring on the tractor by the movement of the tractor head on the tractor;

[0013] The frequency measurement module is used to determine the vibration frequency of the suspended mass by the vibration of the tractor head; wherein, the vibration frequency of the suspended mass is the degree of vibration when the suspended mass rotates around the axis of the balance suspension spindle;

[0014] The inertia measurement module is used to determine the moment of inertia of the suspended mass of the tractor according to the leaf spring stiffness and the vibration frequency.

[0015] Third aspect, the present application provides an electronic device, which includes a processor and a memory. The memory is used to store application programs, and the processor runs or executes the software programs stored in the memory to enable the electronic device to implement the above-mentioned method for measuring the moment of inertia of the suspended mass of the tractor.

[0016] Fourth aspect, the present application provides a computer-readable storage medium, which is used to store program codes executed by a processor, and the program codes are used to implement the above-mentioned method for measuring the moment of inertia of the suspended mass of the tractor.

[0017] Fifth aspect, the present application provides a computer program product, which contains computer instructions. When the computer instructions run on an electronic device, the electronic device is enabled to implement the above-mentioned method for measuring the moment of inertia of the suspended mass of the tractor.

[0018] Beneficial effects:

[0019] The present application provides a method for measuring the moment of inertia of the suspended mass of a tractor. The method includes: determining the leaf spring stiffness of the leaf spring on the tractor by the movement of the tractor head on the tractor; determining the vibration frequency of the suspended mass by the vibration of the tractor head; wherein, the vibration frequency of the suspended mass is the degree of vibration when the suspended mass rotates around the axis of the balance suspension spindle; determining the moment of inertia of the suspended mass of the tractor according to the leaf spring stiffness and the vibration frequency;

[0020] In summary, different from the prior art which adopts an estimation method, the present application first directly measures the load-bearing and deformation relationship of the leaf spring on the tractor through the movement of the vehicle head, thereby determining the stiffness of the leaf spring, avoiding the errors caused by estimation, and ensuring the accuracy of the leaf spring stiffness data. In addition, the present application measures the vibration frequency when the suspension mass pitches around the axis of the balance suspension spindle on the tractor, and ensures the accuracy of the vibration frequency data through direct measurement. In addition, after obtaining the leaf spring stiffness and vibration frequency, the present application can calculate the moment of inertia of the tractor suspension mass around the axis of the balance suspension spindle according to the leaf spring stiffness and vibration frequency. Due to the accuracy of the first two measurements, the finally calculated moment of inertia also has a high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. The following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic flow chart of a method for measuring the moment of inertia of a tractor suspension mass provided by an embodiment of the present application;

[0023] Figure 2 It is a schematic structural diagram of a tractor provided by an embodiment of the present application;

[0024] Figure 3 It is a schematic diagram of the stress-strain curve of a leaf spring provided by an embodiment of the present application;

[0025] Figure 4 It is a schematic diagram of the vibration spectrum curve of a suspension mass provided by an embodiment of the present application;

[0026] Figure 5 It is a schematic structural diagram of a device for measuring the moment of inertia of a tractor suspension mass provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In vehicle design and performance evaluation, in many cases, it is necessary to determine the moment of inertia of the suspension mass around the axis of the balance suspension spindle through experimental measurement or numerical simulation. Among them, the moment of inertia, also known as the moment of inertia, is a physical quantity that describes the inertial characteristics of a rigid body rotating around an axis and is used to measure the degree of difficulty of an object to resist changing its rotational state. The size of the moment of inertia is closely related to the shape of the object, the mass distribution, and the position of the rotation axis.

[0028] In actual operation, most of the existing technical solutions for measuring the moment of inertia of the suspended mass of a freight vehicle adopt the simulation method, that is, fixing the suspended mass at one end of the torsion pendulum to make it rotate freely, and estimating the moment of inertia by measuring the torsion pendulum period and combining the parameters of the torsion pendulum device. However, this method has the disadvantage of large errors.

[0029] To solve the above technical problems, the present application provides a solution for measuring the moment of inertia of the suspended mass of a tractor. The technical solution first determines the stiffness of the leaf spring by the movement of the tractor's cab, and then accurately measures the leaf spring stiffness to provide basic data for subsequent calculation of the moment of inertia of the suspended mass. In addition, the technical solution also determines the vibration frequency of the suspended mass by the vibration of the cab. This vibration frequency can indicate the vibration degree of the suspended mass when rotating around the axis of the balance suspension axle, directly reflecting the dynamic characteristics of the suspended mass. Accurately measuring the vibration frequency is a key step in calculating the moment of inertia because it is directly related to the moment of inertia of the suspended mass. Finally, the moment of inertia is calculated by combining the leaf spring stiffness and the vibration frequency. Since this technical solution is actually measured on the tractor without measuring the suspended mass, this technical solution completely avoids the error sources in the traditional simulation method, thereby improving the accuracy of the moment of inertia measurement.

[0030] In summary, since the technical solution accurately measures the leaf spring stiffness and the vibration frequency of the suspended mass and combines these two to calculate the moment of inertia, it can effectively solve the problem of large errors in measuring the moment of inertia of the suspended mass of a freight vehicle in the prior art.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0032] First, the present application provides a method for measuring the moment of inertia of the suspended mass of a tractor, which is applied to a tractor. A balance suspension is provided on the tractor, and the suspended mass of the tractor can perform pitching vibration around the suspension axle of the balance suspension; as Figure 1 shown, Figure 1 is a schematic flow chart of the method for measuring the moment of inertia of the suspended mass of a tractor provided by an embodiment of the present application. The method includes: S110~S130, details are as follows:

[0033] S110: Determine the leaf spring stiffness of the leaf spring on the tractor by the movement of the cab on the tractor.

[0034] Specifically, as Figure 2 shown, Figure 2This is a schematic diagram of the structure of a tractor provided in an embodiment of the present application. The leaf spring used in the embodiment of the present application for measuring the moment of inertia of the suspended mass is a leaf spring under the front of the vehicle.

[0035] In this step, the leaf spring is deformed by controlling the front of the tractor to move. The leaf spring stiffness is calculated by measuring the stress or strain of the leaf spring under a specific deformation and combining the material properties and geometric dimensions of the leaf spring. The leaf spring stiffness is an important parameter of the suspended mass and has a direct impact on the vibration characteristics of the suspended mass. Therefore, accurate measurement of the leaf spring stiffness is the basis for the subsequent calculation of the moment of inertia.

[0036] In one implementation, S110 includes: Step (1) to Step (3), the details of which are as follows:

[0037] Step (1): Control the front end of the stationary tractor to lift it from its current position to a preset height.

[0038] Specifically, before performing the lifting operation, it is necessary to confirm that the tractor has completely stopped and is in a stable parking state. This can be achieved by checking whether the vehicle's brake system is reliably locked and whether there is sufficient support around the vehicle to prevent it from moving accidentally. To ensure safety, obvious warning signs should also be set up around the lifting area, and non-operating personnel should be prohibited from entering to prevent accidents. In actual operation, it is necessary to select a gantry truck or other lifting equipment that can safely and stably lift the front of the vehicle. The selection of lifting equipment should be based on the weight of the tractor, the front structure, and the requirements of the lifting height. Before using the lifting equipment, it should be fully inspected to ensure that all components (such as hooks, wire ropes, brake systems, etc.) are in good condition and meet safety standards.

[0039] The preset height should be precisely determined based on the structural characteristics of the tractor, the location of the leaf springs and the convenience of measurement. Generally, this height should be high enough to clearly observe the deformation of the leaf springs and facilitate relevant measurements or evaluations. When setting the preset height, the bearing capacity of the suspension mass and the safety of other components must be fully considered. Excessive lifting may cause damage to the suspension mass or other components, so ensure that the lifting height is within a safe range.

[0040] During the lifting process, the front of the vehicle should be lifted slowly and steadily to avoid sudden acceleration or deceleration that may cause vehicle shaking or component damage. When the front of the vehicle is lifted to a height close to the preset height, the position and height of the lifting equipment should be adjusted with special care to ensure that the front of the vehicle can stay accurately and stably at the preset position.

[0041] After the tractor head is safely lifted to the preset height, the suspension mass of the tractor should be slowly rotated around the suspension spindle of the balanced suspension. During the rotation process, the deformation of the leaf spring should be closely observed. The leaf spring will undergo a certain degree of tensile or compressive deformation, which is a normal physical phenomenon. However, it should be ensured that the deformation is within the elastic working range to avoid plastic deformation or damage caused by exceeding the elastic limit of the material.

[0042] In actual operation, if it is found that the deformation of the leaf spring is abnormal or exceeds the expected range, the rotation should be stopped immediately and the cause should be checked. If necessary, the lifting height should be adjusted or other measures should be taken to ensure the accuracy and safety of the measurement.

[0043] To sum up, step (1) is an important link in the process of measuring the moment of inertia of the suspension mass of the tractor. It is necessary to strictly control the operation process to ensure that the tractor is in a stationary and stable state, select appropriate lifting equipment, accurately determine the preset height and closely observe the deformation of the leaf spring. Through the above measures, the accuracy and safety of the measurement can be ensured, providing reliable data support for the subsequent process of measuring the moment of inertia of the suspension mass.

[0044] Step (2): Control the tractor head to move downward from the preset height at the preset speed and measure the deformation amount of the leaf spring in the vertical direction and the bearing weight of the leaf spring during the movement.

[0045] Specifically, during the execution of step (2), it is necessary to ensure that the lifting equipment can lower the tractor head smoothly and controllably. At the same time, instruments for measuring the deformation amount and bearing weight of the leaf spring, such as an electronic scale and a height gauge, need to be prepared. Among them, the electronic scale can be set on the lower side of the middle part of the leaf spring, and a bracket can also be set between the electronic scale and the plate.

[0046] In actual operation, as the tractor head descends, due to the gradually increasing pressure on the leaf spring, the deformation amount and the bearing weight gradually increase. During the above process, the electronic scale and the height gauge will record data such as the deformation amount and the bearing weight of the leaf spring in real time.

[0047] It should be emphasized that the selection of the preset speed should consider the deformation speed of the leaf spring and the measurement accuracy. Usually, a slower speed is selected to ensure the accuracy of the measured data. Among them, the preset speed can be calculated by establishing a physical model of the suspension mass of the tractor and using the dynamic equation. This method requires accurate understanding of the physical parameters of the system, such as mass, stiffness, damping, etc. In addition, an empirical formula between the preset speed and other physical quantities (such as vibration frequency, stiffness, etc.) can also be fitted through a large amount of experimental data. This method depends on the accuracy and comprehensiveness of the experimental data. In addition, historical data can also be collected and analyzed to find the optimal value or range of the preset speed.

[0048] Through step (2), the bearing weight data of the leaf spring under different deformation states can be obtained, which provides reliable experimental data for the subsequent calculation of the leaf spring stiffness. In actual operation, step (2) is also helpful to evaluate the performance and stability of the leaf spring under different working conditions.

[0049] Step (3): Determine the leaf spring stiffness of the leaf spring based on the deformation and the load-bearing capacity.

[0050] Specifically, in the embodiments of the present application, the leaf spring stiffness is a physical quantity that describes the leaf spring's ability to resist deformation under force, and is usually expressed as the amount of deformation produced by the leaf spring per unit length when subjected to a unit force. The greater the stiffness, the smaller the leaf spring's deformation when subjected to force, and the stronger its ability to resist deformation.

[0051] In the embodiment of the present application, the deformation of the leaf spring under different loads is obtained by experimental measurement, and the stress-strain curve of the leaf spring can be drawn. Figure 3 As shown, Figure 3 A schematic diagram of a stress-strain curve of a leaf spring provided in an embodiment of the present application, Figure 3 The horizontal axis represents the deformation variable. Figure 3 The vertical axis represents the load-bearing capacity. The curve reflects the relationship between stress and strain of the leaf spring during the force-bearing process and is an important basis for evaluating the performance of the leaf spring.

[0052] The drawing of stress-strain curve requires accurate experimental data, including the load and the corresponding deformation. Through the precise measurement of the experimental equipment, the above data can be obtained and the curve can be drawn. After the stress-strain curve is obtained, the curve can be processed by linear regression analysis or other mathematical methods to calculate the stiffness of the leaf spring.

[0053] Linear regression analysis is a commonly used mathematical method that can approximate the stress-strain curve by fitting a straight line to obtain the stiffness value of the leaf spring. In addition to linear regression analysis, other mathematical methods such as polynomial fitting and exponential fitting can also be considered. The most appropriate method can be selected according to the specific situation of the experimental data.

[0054] Among them, the leaf spring stiffness The calculation formula is as follows:

[0055] ;

[0056] in, The stress-strain curve The slope of a data set; the data set can be any two data points in the stress-strain curve; Indicates the total number of data groups.

[0057] In actual operation, it is necessary to conduct a detailed analysis and processing of the experimental data. This includes steps such as data cleaning, denoising, and normalization to ensure the accuracy and reliability of the data. By analyzing the experimental data, the deformation amount of the leaf spring under different load weights can be obtained, and then the stiffness value of the leaf spring can be calculated. The stiffness values in different deformation states can also be compared to evaluate the stiffness and elastic performance of the leaf spring.

[0058] The stiffness value of the leaf spring obtained through step (3) is an important parameter for subsequent calculation of the moment of inertia of the suspension mass of the tractor around the axis of the balance suspension spindle. The calculation of the moment of inertia needs to consider the rigidity and mass distribution of the suspension mass, and the leaf spring stiffness is one of the key factors.

[0059] In addition, the leaf spring stiffness also provides an important basis for the design, optimization, and simulation analysis of the tractor suspension mass. When designing the suspension mass, it is necessary to select an appropriate leaf spring stiffness according to factors such as the driving conditions and load requirements of the vehicle to ensure the performance and reliability of the suspension mass.

[0060] In the optimization and simulation analysis, the leaf spring stiffness is also an important input parameter. By adjusting the leaf spring stiffness value, the performance of different suspension masses can be simulated, providing strong support for the design and improvement of the vehicle.

[0061] In summary, step (3) is a key link for evaluating the performance of the leaf spring, optimizing the design of the suspension mass, and calculating the moment of inertia. Through accurate experimental measurement and data analysis, the stiffness value of the leaf spring can be obtained, providing an important parameter basis for subsequent calculations and analyses.

[0062] In summary, through the detailed operations of steps (1) to (3), the stiffness of the leaf spring on the tractor can be accurately measured, providing reliable experimental data and a theoretical basis for subsequent calculation of the moment of inertia. This method not only improves the accuracy of the measurement but also provides strong support for the design and optimization of the tractor suspension mass.

[0063] In one implementation, before S110, the method further includes: steps (4) to (6), details are as follows:

[0064] Step (4): Predict the mass of the suspension mass to obtain the predicted mass.

[0065] Specifically, in the embodiment of the present application, during the measurement of the moment of inertia of the tractor suspension mass, in order to more accurately determine the stiffness of the leaf spring, it is necessary to predict the suspension mass before the measurement and adjust the measurement parameters according to the prediction results, such as the preset height.

[0066] In actual operation, basic information of the tractor is collected, including but not limited to historical data of the vehicle such as the model. Based on the historical data, a correlation model between the suspension quality and factors such as the model and configuration is established. Through this model, the suspension quality of the tractor can be predicted according to the configuration of the current tractor; the historical data refers to the historical suspension quality and historical preset height of the tractor.

[0067] In addition, the suspension mass can be estimated by combining the structural characteristics of the tractor with the principles of physics. For example, the approximate value of the suspension mass can be calculated based on factors such as the total mass of the vehicle, the distribution of the front and rear axle loads, and the geometric dimensions of the suspension mass.

[0068] For example, suppose the model and suspension configuration of the tractor are known. By consulting the data provided by the manufacturer, it is known that the suspension mass of this model with similar configuration is about 5 tons. At the same time, according to the physical model estimation, the suspension mass of this model is also about 5 tons. Therefore, it can be predicted that the current tractor suspension mass is 5 tons.

[0069] Step (5): According to the predicted quality, determine the current quality level to which the predicted quality belongs from a plurality of candidate quality levels.

[0070] Specifically, in the embodiment of the present application, the tractor suspension mass is divided into a plurality of mass gears according to the possible range of the tractor suspension mass. For example, it can be set to gears such as less than 3 tons, 3-5 tons, 5-7 tons, and more than 7 tons. The predicted mass is matched with the divided mass gears to determine the current mass gear to which the predicted mass belongs. Now, taking the predicted mass of 5 tons as an example, in the divided mass gears, 5 tons belongs to the gear range of 5-7 tons, so it can be determined that the current mass gear of the suspension mass is 5-7 tons.

[0071] In actual operation, accurate determination of the division intervals can be used to more accurately control vehicle performance, optimize suspension quality design, or meet different transportation needs. Therefore, it is necessary to formulate the division criteria as accurately as possible to ensure that the interval division meets actual needs. First, it is necessary to analyze the overall range of the suspension quality of tractors corresponding to different models in daily situations, usually including the quality of the vehicle when it is unloaded, the quality when it is fully loaded, and possible overload conditions. By analyzing the quality range, the number and approximate range of the intervals can be preliminarily determined.

[0072] After initially determining the number and approximate range of intervals, specific classification criteria can be formulated according to the mass range. The above criteria can be specific numerical values based on weight, or can be based on a certain ratio or relative value. For example, the mass range can be equally divided into several intervals, or the classification criteria can be formulated according to factors such as the designed load of the tractor and the actual usage scenario; when formulating the classification criteria, the convenience and operability in actual application also need to be considered. The number of intervals should not be too many or too few. Too many will increase the management difficulty, and too few may not meet the actual needs; the range of intervals should cover all possible situations of the suspension mass of the tractor as much as possible to ensure that each mass value can find a corresponding interval.

[0073] After formulating the classification criteria, verification and adjustment are required. The suspension mass of the tractor can be actually measured and compared with the divided intervals to verify the rationality and accuracy of the intervals. If it is found that there are unreasonable or inaccurate parts in the interval division, timely adjustment and optimization are needed.

[0074] Step (6): Determine the preset height of the suspension mass according to the correspondence between the mass gear and the preset height and the current mass gear.

[0075] Specifically, based on experimental experience and theoretical analysis, establish the correspondence between the mass gear and the preset height. This correspondence can be determined according to the characteristics of the suspension mass and the measurement requirements. According to the current mass gear and the established correspondence, determine the preset height applicable to the suspension mass.

[0076] For example, assume that in the experiment, the following correspondence between the mass gear and the preset height has been established: below 3 tons corresponds to preset height A, 3 - 5 tons corresponds to preset height B, 5 - 7 tons corresponds to preset height C, and above 7 tons corresponds to preset height D. Since the current mass gear of the suspension mass is 5 - 7 tons, the preset height can be determined as C.

[0077] Through the operations of steps (4) to (6), the measurement parameters (such as the preset height) can be adjusted according to the prediction result of the suspension mass of the tractor, so as to measure the stiffness of the leaf spring more accurately and provide reliable data support for the subsequent calculation of the moment of inertia. This method not only improves the accuracy of the measurement, but also enhances the flexibility and applicability of the measurement.

[0078] S120: Determine the vibration frequency of the suspension mass through the vibration of the vehicle head;

[0079] Among them, the vibration frequency of the suspension mass is the degree of vibration when the suspension mass rotates around the axis of the balance suspension spindle.

[0080] Specifically, in this step, the vibration of the tractor head is controlled, which in turn drives the sprung mass to rotate around the axis of the balance suspension spindle. Measuring devices such as vibration sensors or accelerometers are used to collect the vibration signals of the sprung mass in real time. By performing spectral analysis on the vibration signals, the vibration frequency of the sprung mass is extracted. The vibration frequency reflects the degree of vibration of the sprung mass during rotation and is a key parameter for calculating the moment of inertia.

[0081] In one implementation, S120 includes steps (7) to (8), details are as follows:

[0082] Step (7): Control the tractor head in a stationary state to vibrate, so that the sprung mass vibrates within a preset amplitude and measure the vibration data of the sprung mass during the vibration process.

[0083] Specifically, during the execution of step (7), the tractor is placed in a stationary state to ensure vehicle stability; in actual operation, a hydraulic or electric device is used to control the up-and-down vibration of the tractor head, and the vibration amplitude is set according to the preset amplitude. During the vibration process, a vibration sensor or accelerometer is installed on the bottom side of the tractor head to collect vibration data in real time.

[0084] For example, when the tractor is in an unloaded state, the preset amplitude can be 5 cm. The tractor head is controlled to vibrate up and down in the form of a sine wave with a frequency of 1 Hz by a control device. The vibration sensor records the acceleration change of the sprung mass in real time; when the tractor is fully loaded, the preset amplitude can be 11 cm.

[0085] Step (8): Determine the vibration frequency of the sprung mass in the vertical direction according to the vibration data.

[0086] Specifically, the collected vibration data is preprocessed to remove noise and outliers. Spectral analysis methods such as Fast Fourier Transform (FFT) are used to process the vibration data to obtain a vibration spectrum curve, as Figure 4 shown, Figure 4 is a schematic diagram of the vibration spectrum curve of the sprung mass provided by the embodiment of the present application. The main vibration frequency peak is determined in the vibration spectrum curve, which is the vibration frequency of the sprung mass in the vertical direction.

[0087] In actual operation, the collected acceleration data is processed by FFT (Fast Fourier Transform), and a vibration spectrum curve is obtained. In the spectrum curve, the main vibration frequency peak appears at 2.5 Hz, so the vibration frequency of the sprung mass is determined to be 2.5 Hz.

[0088] Among them, the vibration frequency The calculation formula is as follows:

[0089] ; ;

[0090] In the formula, represents the vibration period of the tractor's suspended mass; represents the period of the th data group of the vibration frequency spectrum curve; represents the total number of data groups; the data group can be the time interval between two adjacent wave peaks and wave valleys in the vibration frequency spectrum curve.

[0091] In one implementation, before S120, the method further includes: steps (9) to (11), details are as follows:

[0092] Step (9): Predict the predicted mass for the suspended mass.

[0093] Step (10): Determine the current mass gear to which the predicted mass belongs among multiple alternative mass gears according to the predicted mass.

[0094] Specifically, the content of steps (9) to (10) can refer to the description content of steps (4) to (5).

[0095] Step (11): Determine the preset amplitude of the suspended mass according to the correspondence between the mass gear and the preset amplitude and the current mass gear.

[0096] Specifically, the mass gear is a classification index describing the mass borne by the suspended mass, usually divided according to the vehicle's load or the designed load-bearing capacity of the suspended mass. The preset amplitude refers to the vibration amplitude that the suspended mass is expected to reach under specific excitation. The size of the amplitude directly affects the driving smoothness, riding comfort, and durability of the suspended mass of the vehicle.

[0097] Establishing the correspondence between the mass gear and the preset amplitude is to ensure that the suspended mass can maintain appropriate vibration characteristics at different mass gears, neither vibrating excessively nor being too rigid. When establishing the correspondence between the mass gear and the preset amplitude, the principle of "the lower the mass gear, the larger the preset amplitude; the higher the mass gear, the smaller the preset amplitude" is usually followed. This is because when the mass borne by the suspended mass is small, in order to maintain sufficient sensitivity and responsiveness, a larger amplitude needs to be set to ensure that the suspended mass can effectively absorb and buffer vibrations. And when the mass borne by the suspended mass is large, in order to maintain the stability and safety of the vehicle, the amplitude needs to be reduced to avoid excessive vibration and damage to the suspended mass.

[0098] In actual operation, first, it is necessary to accurately obtain the mass borne by the suspended mass through sensors or other measuring devices and determine the current mass range according to the preset mass range division standard. After determining the current mass range, the corresponding preset amplitude can be found according to the previously established corresponding relationship. For example, if the current mass range is 2 - 4 tons, then according to the corresponding relationship, the preset amplitude should be 5 cm.

[0099] The determined preset amplitude will be used as a reference standard in the performance test, optimization, and actual control of the suspended mass. In the performance test, the performance of the suspended mass can be evaluated by comparing the difference between the actual amplitude and the preset amplitude to see if it meets the design requirements. During the optimization process, the preset amplitude can be adjusted according to actual needs to optimize the vibration characteristics of the suspended mass. In actual control, the preset amplitude can be used as a control target, and the amplitude can be precisely controlled by adjusting the parameters of the suspended mass (such as damping force, stiffness, etc.).

[0100] For example, different suspended masses correspond to different mass ranges, and each mass range corresponds to a preset amplitude. When the vehicle is unloaded (low mass range), the preset amplitude of the suspended mass is set to a larger value (such as 5 cm) to ensure better ride comfort and driving stability when the vehicle encounters bumpy roads. When the vehicle is fully loaded (high mass range), the preset amplitude of the suspended mass is set to a smaller value (such as 2 cm) to avoid damage to the vehicle and goods caused by excessive vibration.

[0101] In summary, step (11) provides an important reference standard for the performance test, optimization, and actual control of the suspended mass by establishing the corresponding relationship between the mass range and the preset amplitude and determining the preset amplitude applicable to the suspended mass according to the current mass range.

[0102] S130: Determine the moment of inertia of the tractor's suspended mass according to the leaf spring stiffness and vibration frequency.

[0103] Specifically, in this step, the moment of inertia of the suspended mass is calculated by combining the previously measured leaf spring stiffness and the vibration frequency of the suspended mass, using the dynamic equation or empirical formula. The dynamic equation can be established based on the physical model and mechanical principles of the suspended mass, and the empirical formula can be obtained by fitting experimental data. By substituting the measured leaf spring stiffness and vibration frequency into the equation or formula, the moment of inertia of the suspended mass is solved.

[0104] In one implementation, S130 includes: step (12), details are as follows:

[0105] Step (12): Determine the moment of inertia of the suspended mass according to the leaf spring stiffness, vibration frequency, and moment of inertia calculation formula;

[0106] Among them, the formula for calculating the moment of inertia is as follows:

[0107]

[0108] In the formula, represents the sprung mass of the tractor; represents the distance between the longitudinal center point of the leaf spring and the axis center of the balance suspension spindle; represents the leaf spring stiffness; represents the vibration frequency.

[0109] Specifically, during the execution of step (12), it is necessary to ensure that the leaf spring stiffness , the vibration frequency and the distance between the longitudinal center point of the leaf spring and the axis center of the balance suspension spindle have been accurately measured and recorded. In actual operation, after the calculation is completed, it is necessary to check the result to determine whether it is reasonable and conforms to physical reality.

[0110] If the result is abnormal, such as the moment of inertia being too large or too small, the accuracy of the measured data and the correctness of the formula application should be checked. Possible reasons include measurement errors, data recording errors, or improper use of the formula, etc. If an abnormal result is found, the accuracy of the measured data should be checked first. It can be verified by repeated measurements, using different measurement devices or methods.

[0111] The determined moment of inertia will be an important parameter for the dynamic analysis of the sprung mass, and can be used to evaluate the stability, responsiveness of the sprung mass and optimize the design of the sprung mass. In vehicle dynamics simulation, sprung mass tuning, and vehicle performance evaluation, the moment of inertia is an indispensable parameter.

[0112] In actual operation, the formula for calculating the moment of inertia provided in the embodiment of the present application is determined based on writing the rotational differential equation for the spindle, and the derivation process is as follows:

[0113] Among them, the rotational differential equation is as follows:

[0114] ;

[0115] Performing deformation processing on the above equation yields the following formula:

[0116] ;

[0117] Let in the above formula, then according to the differential equation theory is the vibration frequency, and the formula for calculating the moment of inertia can be obtained.

[0118] In summary, in the embodiment of the present application, the load-bearing and deformation relationship of the leaf spring is directly measured on the tractor by moving the head of the vehicle first, so as to determine the stiffness of the leaf spring, avoiding errors caused by estimation and ensuring the accuracy of the leaf spring stiffness data. In addition, in the embodiment of the present application, the vibration frequency of the suspension mass during pitching vibration around the axis of the balance suspension spindle is measured on the tractor. By means of direct measurement, the accuracy of the vibration frequency data is ensured. In addition, after obtaining the leaf spring stiffness and vibration frequency, the embodiment of the present application can calculate the moment of inertia of the tractor suspension mass around the axis of the balance suspension spindle according to the leaf spring stiffness and vibration frequency. Due to the accuracy of the first two measurements, the finally calculated moment of inertia also has a high accuracy.

[0119] It should be emphasized that since the embodiment of the present application directly measures the leaf spring stiffness and the vibration frequency of the suspension mass, avoiding the errors brought by the estimation method in the prior art, it can significantly improve the measurement accuracy of the moment of inertia. In addition, since the measurement method provided by the embodiment of the present application is applicable to various types of tractors and is not limited by the specific structure or configuration of the vehicle, it has strong versatility and adaptability. In addition, the measurement tools and operation steps required by the embodiment of the present application are relatively simple and are easy to implement in the laboratory or on-site, reducing the measurement cost and time cost. Therefore, it has broad application prospects and practical value.

[0120] In a second aspect, the present application provides a device for measuring the moment of inertia of a tractor suspension mass, which is applied to a tractor. A balance suspension is provided on the tractor, and the tractor suspension mass can perform pitching vibration around the suspension spindle of the balance suspension; as Figure 5 shown, Figure 5 is a schematic structural diagram of the device for measuring the moment of inertia of a tractor suspension mass provided by an embodiment of the present application. The device includes: a stiffness measurement module 210, a frequency measurement module 220, and an inertia measurement module 230;

[0121] The stiffness measurement module 210 is used to determine the leaf spring stiffness of the leaf spring on the tractor by moving the head of the tractor.

[0122] The frequency measurement module 220 is used to determine the vibration frequency of the suspension mass by the vibration of the head. Wherein, the vibration frequency of the suspension mass is the degree of vibration when the suspension mass rotates around the axis of the balance suspension spindle;

[0123] The inertia measurement module 230 is used to determine the moment of inertia of the tractor suspension mass according to the leaf spring stiffness and the vibration frequency.

[0124] In one implementation, the stiffness measurement module 210 is further used to control the head of the stationary tractor to be lifted from the current position to a preset height;

[0125] The stiffness measurement module 210 is further configured to control the vehicle head to move downward from a preset height at a preset speed and measure the deformation of the leaf spring in the vertical direction and the load-bearing capacity of the leaf spring during the movement;

[0126] The stiffness measurement module 210 is further configured to determine the leaf spring stiffness of the leaf spring according to the deformation and the load-bearing capacity.

[0127] In one embodiment, the stiffness measurement module 210 is further configured to predict the suspended mass to obtain a predicted mass;

[0128] The stiffness measurement module 210 is further configured to determine the current mass range to which the predicted mass belongs among multiple alternative mass ranges according to the predicted mass;

[0129] The stiffness measurement module 210 is further configured to determine the preset height of the suspended mass according to the correspondence between the mass range and the preset height and the current mass range.

[0130] In one embodiment, the frequency measurement module 220 is further configured to control the vehicle head of the stationary tractor to vibrate, so that the suspended mass vibrates within a preset amplitude and measure the vibration data of the suspended mass during the vibration;

[0131] The frequency measurement module 220 is further configured to determine the vibration frequency of the suspended mass in the vertical direction according to the vibration data.

[0132] In one embodiment, the frequency measurement module 220 is further configured to predict the suspended mass to obtain a predicted mass;

[0133] The frequency measurement module 220 is further configured to determine the current mass range to which the predicted mass belongs among multiple alternative mass ranges according to the predicted mass;

[0134] The frequency measurement module 220 is further configured to determine the preset amplitude of the suspended mass according to the correspondence between the mass range and the preset amplitude and the current mass range.

[0135] In one embodiment, the inertia measurement module 230 is further configured to determine the moment of inertia of the suspended mass according to the leaf spring stiffness, the vibration frequency, and the moment of inertia calculation formula; the moment of inertia calculation formula is as follows:

[0136]

[0137] In the formula, represents the suspended mass of the tractor;

[0138] represents the distance between the longitudinal center point of the leaf spring and the axis center of the balance suspension spindle;

[0139] represents the stiffness of the leaf spring; represents the vibration frequency.

[0140] Thirdly, the present application further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of S110 - S130 provided in the above - mentioned embodiments are implemented.

[0141] Fourthly, the present application further provides a computer - readable storage medium. A computer program is stored on the computer - readable storage medium. When the computer program is run by a processor, the steps of S110 - S130 in the above - mentioned embodiments are executed.

[0142] Fifthly, the computer program product provided by the present application includes a computer - readable storage medium storing program code. The instructions included in the program code can be used to execute the methods in the foregoing method embodiments. For specific implementation, reference can be made to the steps of S110 - S130 in the method embodiments, which will not be elaborated herein.

[0143] In the embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some communication interfaces. The indirect couplings or communication connections of the devices or units can be electrical, mechanical, or other forms.

[0144] In addition, the units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or can also be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0145] Furthermore, in each embodiment of the present application, the functional modules can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0146] It should be noted that if a function is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0147] In this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0148] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for measuring the moment of inertia of the suspended mass of a tractor, characterized in that: Applied to a tractor, the tractor is provided with a balancing suspension, and the tractor suspension mass can perform pitch vibration around the suspension spindle of the balancing suspension; the method comprises: Determining the leaf spring stiffness of the leaf spring on the tractor by moving the head of the tractor; Determining the vibration frequency of the suspended mass by the vibration of the front of the vehicle; The vibration frequency of the suspended mass is the vibration degree of the suspended mass when it rotates around the axis of the balance suspension spindle; determining the moment of inertia of the suspended mass of the tractor vehicle based on the leaf spring stiffness and the vibration frequency; The method of determining the leaf spring stiffness of the leaf spring on the tractor by moving the head of the tractor comprises: Controlling the front of the tractor in a stationary state to lift it from a current position to a preset height; Controlling the vehicle head to move downward from the preset height at a preset speed and measuring the deformation amount of the leaf spring in the vertical direction and the bearing weight of the leaf spring during the movement; Determining the leaf spring stiffness of the leaf spring according to the deformation amount and the load-bearing weight; Determining the vibration frequency of the suspended mass by the vibration of the vehicle head includes: Controlling the front of the tractor in a stationary state to vibrate so that the suspended mass vibrates within a preset amplitude and measuring vibration data of the suspended mass during the vibration process; determining a vibration frequency of the suspended mass in a vertical direction according to the vibration data; Determining the moment of inertia of the tractor suspension mass according to the leaf spring stiffness and the vibration frequency includes: The moment of inertia of the suspended mass is determined according to the leaf spring stiffness, the vibration frequency and the moment of inertia calculation formula; wherein the moment of inertia calculation formula is as follows: In the formula, represents the suspended mass of the tractor; Indicates the distance between the longitudinal center point of the leaf spring and the axis center of the balancing suspension spindle; represents the leaf spring stiffness; represents the vibration frequency.

2. The method according to claim 1, characterized in that Before determining the leaf spring stiffness of the leaf spring on the tractor by moving the head of the tractor, the method further comprises: Predicting the suspension mass to obtain a predicted mass; According to the predicted quality, determining a current quality level to which the predicted quality belongs among a plurality of alternative quality levels; The preset height of the suspended mass is determined according to the corresponding relationship between the mass level and the preset height and the current mass level.

3. The method according to claim 1, characterized in that Before determining the vibration frequency of the suspended mass by the vibration of the vehicle head, the method further includes: Predicting the suspension mass to obtain a predicted mass; According to the predicted quality, determining a current quality level to which the predicted quality belongs among a plurality of alternative quality levels; The preset amplitude of the suspended mass is determined according to the corresponding relationship between the mass gear and the preset amplitude and the current mass gear.

4. A device for measuring the moment of inertia of a tractor suspension mass, characterized in that: The method for implementing claim 1 is applied to a tractor, wherein the tractor is provided with a balancing suspension, and the tractor suspension mass can perform pitch vibration around the suspension spindle of the balancing suspension; the device comprises: a stiffness measurement module, a frequency measurement module and an inertia measurement module; The stiffness determination module is used to determine the leaf spring stiffness of the leaf spring on the tractor by moving the head of the tractor; The frequency determination module is used to determine the vibration frequency of the suspended mass through the vibration of the vehicle head; wherein the vibration frequency of the suspended mass is the vibration degree of the suspended mass when it rotates around the axis of the balance suspension spindle; The inertia determination module is used to determine the rotational inertia of the suspended mass of the tractor according to the leaf spring stiffness and the vibration frequency.

5. An electronic device, characterized in that: The electronic device comprises a processor and a memory, wherein the memory is used to store an application program, and the processor runs or executes the application program stored in the memory so that the electronic device implements the method for measuring the moment of inertia of the suspension mass of a tractor according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes executed by a processor, and the program codes are used to implement the method for measuring the moment of inertia of the suspended mass of a tractor according to any one of claims 1 to 3.

7. A computer program product, characterized in that The computer program product comprises computer instructions. When the computer instructions are run on an electronic device, the electronic device implements the method for measuring the moment of inertia of the suspended mass of a tractor vehicle according to any one of claims 1 to 3.

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