Method, system and equipment for calculating tire static load radius of empty lorry and medium

Abstract

The invention provides a method, a system, equipment and a medium for calculating the static load radius of a tire when a lorry is empty, and belongs to the technical field of automobile manufacturing and inspection. According to the influence degree of the change of each influence factor on the no-load radius of the tire, screening out influence factors required by calculation of the no-load radius of the tire; establishing a tire no-load radius calculation formula by using each influence factor; parameter values of all the influence factors are obtained and input into a tire no-load radius calculation formula, and a tire no-load radius calculation value is obtained; and verifying the accuracy of the tire no-load radius calculation value. According to the method, factors such as the outer diameter of the tire, the internal air pressure, the vehicle load and the radial rigidity are comprehensively considered, a function formula is established, the no-load radius of the tire is rapidly calculated, and the accuracy is verified through measured data.

Description

Background Art

[0002] The height of the vehicle affects driving stability, the vehicle's performance in passing various terrains, and the vehicle's fuel economy. It is an important measure of vehicle compliance and safety. Therefore, in the vehicle registration and factory inspection process of heavy-duty trucks, the accuracy requirements for the vehicle height are very high. However, the accurate calculation of the vehicle height depends on the key parameter of the tire's unloaded radius.

[0003] The unloaded radius of a tire is the radius of the tire when it is not subject to additional load. It is a complex and variable physical quantity that is affected by multiple factors such as the tire's outer diameter, internal air pressure, load, and the radial stiffness of the tire material itself. The interaction of these factors leads to the complexity and uncertainty of the tire's unloaded radius measurement calculation. Traditional tire unloaded radius measurement methods, such as direct measurement method and air pressure adjustment method, are not only cumbersome, time-consuming and labor-intensive, but the measurement accuracy is often restricted by multiple factors such as the operator's technical level, measurement tool performance, and environmental conditions. In addition, tires of different models and specifications have differences in structure and material, making it difficult for traditional measurement methods to be uniformly applied to various tires.

[0004] This is a shortcoming of the prior art. Therefore, in view of the above-mentioned defects in the prior art, it is very necessary to provide a method, system, equipment and medium for calculating the static load radius of the tire of a truck when it is empty. Summary of the invention

[0005] In view of the defects that the unloaded radius of the tire in the prior art is a key parameter for calculating the height of the entire vehicle, there are calculation complexity and uncertainty due to many influencing factors, the traditional measurement method is cumbersome to operate, and is restricted by multiple factors and is difficult to be uniformly applied to various tires. The present invention provides a calculation method, system, equipment and medium for the static load radius of the tire of a truck when it is empty to solve the above technical problems.

[0006] In a first aspect, the present invention provides a method for calculating the static load radius of a tire of an empty truck, comprising the following steps: S1. Obtain the influencing factors of the tire unloaded radius, and select the influencing factors required for calculating the tire unloaded radius according to the degree of influence of the changes of each influencing factor on the tire unloaded radius; S2. Use various influencing factors to establish a tire unloaded radius calculation formula; S3. Obtain the parameter values ​​of each influencing factor and input them into the tire unloaded radius calculation formula to obtain the calculated value of the tire unloaded radius; S4. Verify the accuracy of the calculated value of the tire unloaded radius. Furthermore, the specific steps of step S1 are as follows: S11. Obtaining factors affecting the tire's unloaded radius, the factors including the tire's outer diameter, static load radius, air pressure, tire load, and radial stiffness of the tire; S12. Determine the upper and lower limits of the fluctuation range of each influencing factor; S13. Identify an influencing factor; S14. Control the influencing factors of positioning to change within the upper and lower limits of the fluctuation range, and control the remaining influencing factors to remain unchanged, and measure the maximum change in the tire unloaded radius during the change of the influencing factors of positioning; S15. Identify whether the maximum change in tire unloaded radius exceeds a set change threshold; If yes, go to step S16; If not, the factors affecting positioning are taken as influencing factors; S16. Determine whether all influencing factors have been located; If yes, go to step S17; If not, locate the next influencing factor and return to step S14; S17. Determine the obtained influencing factors, wherein the influencing factors include the outer diameter of the tire, the static load radius, the air pressure, the radial stiffness, and the tire load.

[0007] Furthermore, the specific steps of step S2 are as follows: S21. Set the tire outer diameter d, tire standard load g1, and tire static load r in the truck tire standard. f ; S22. Set the maximum tire load g for vehicles of the same series but different models when empty max and the minimum tire load when the vehicle is empty (g) min ; S23. Calculate the radial stiffness of the tire under standard conditions and use it as the standard stiffness z1, obtain the minimum stiffness z2 of tires from different manufacturers, and then calculate the maximum load g of the tire when the vehicle is empty based on the standard stiffness z1, the minimum stiffness z2, and the maximum load g of the tire when the vehicle is empty. max and the minimum tire load when the vehicle is empty (g) min Construct an expression for the stiffness compensation coefficient k; S24. Calculate the tire sinking amount under the standard state unit load as the unit sinking amount h0; S25. Based on the unit sinking h0 and the actual tire load g when the vehicle is empty act Calculate the tire sinking amount h under time load when the vehicle is empty act ; S26. According to the actual sinking amount h act The general formula of tire unloaded radius is constructed by using the stiffness compensation coefficient k; S27. Use the general formula for tire unloaded radius to calculate the maximum tire load (g) when the vehicle is unloadedmax The corresponding minimum no-load radius r min , and use the general formula for tire unloaded radius to calculate the minimum tire load g when the vehicle is unloaded min The corresponding maximum no-load radius r max ; S28. Use the maximum empty radius r max and the minimum no-load radius r min Calculate the mean value r of the unloaded radius to obtain the calculation formula for the tire unloaded radius, and then set the tolerance of the tire unloaded radius based on the differences between different models of vehicles in the same series.

[0008] Furthermore, the specific steps of step S23 are as follows: S231. Obtain the expression of the force and the displacement distance under the standard tire load; S232. Construct a radial stiffness expression according to the force expression and the displacement distance expression, and calculate the radial stiffness of the tire under the standard state according to the standard tire load g1 and the displacement distance under the standard tire load to obtain the standard stiffness z1; S233 obtains the stiffness of tires from different manufacturers and finds the minimum stiffness z2; S234. Maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min Calculate the tire sinking amount when the standard stiffness is z1 as the standard sinking amount; S235. Maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min Calculate the tire sinking amount when the minimum stiffness z2 is reached as the minimum sinking amount; S236. The difference between the standard sinking amount and the minimum sinking amount is used as the stiffness compensation coefficient k, and the standard stiffness z1, the minimum stiffness z2, and the maximum tire load g when the vehicle is empty are obtained. max and the minimum tire load when the vehicle is empty (g) min Expression that characterizes the stiffness coefficient k.

[0009] Furthermore, the tolerance of the tire unloaded radius set in step S28 is ±15 mm.

[0010] Furthermore, the specific steps of step S3 are as follows: S31. Collect the minimum load of a single tire when the guide wheel of the type of vehicle to be inspected is empty as the minimum tire load when the vehicle is empty. min , and the maximum load of a single tire as the maximum tire load when the vehicle is empty g max ; S32. Compare the standard stiffness z1 with the minimum stiffness z2; If z1>z2, the stiffness coefficient k=0, and the process goes to step S33; If z1≤z2, go to step S32; S32. Based on the standard stiffness z1, minimum stiffness z2, and maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min , and use the expression of stiffness coefficient k to calculate the stiffness coefficient k; S33. Based on the tire outer diameter d, tire static load r f , Standard tire load g1, Maximum tire load when the vehicle is empty g max , Minimum tire load when empty g min和 The stiffness compensation coefficient k is used, and the tire unloaded radius calculation formula is used to calculate the tire unloaded radius mean r; S34. Introducing a set tolerance into the tire unloaded radius mean r to obtain a calculated value of the tire unloaded radius of the type of vehicle to be inspected.

[0011] Furthermore, the specific steps of step S4 are as follows: S41. Obtain tire unloaded radius test value from tire radial stiffness test report of different tire manufacturers of vehicles of different types to be tested; S42. Verify whether the tire unloaded radius detection value of each manufacturer is within the tolerance range of the tire unloaded radius calculation value; S43. Calculate the vehicle height based on the calculated value of the tire unloaded radius, and compare the calculated vehicle height with the announced value of the vehicle height to verify the accuracy of the tire unloaded radius calculation.

[0012] In a second aspect, the present invention provides a system for calculating the static load radius of a tire of an empty truck, comprising: The influencing factor screening module is used to obtain the influencing factors of the tire unloaded radius, and screen out the influencing factors required for calculating the tire unloaded radius according to the degree of influence of the changes of each influencing factor on the tire unloaded radius; A calculation formula building module is used to establish a tire unloaded radius calculation formula using various influencing factors; The no-load radius calculation module is used to obtain the parameter value of each influencing factor and input it into the tire no-load radius calculation formula to obtain the tire no-load radius calculation value; The calculation accuracy verification module is used to verify the accuracy of the calculated value of the tire unloaded radius.

[0013] In a third aspect, the present invention provides an electronic device, including a processor and a memory; The memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the electronic device executes the method described in the first aspect above.

[0014] In a fourth aspect, the present invention provides a storage medium, The storage medium stores instructions, which, when executed on a computer, enable the computer to execute the method described in the first aspect.

[0015] The beneficial effects of the present invention are: The present invention provides a method, system, device and medium for calculating the static load radius of a tire of an empty truck. By comprehensively considering factors such as the tire outer diameter, internal air pressure, vehicle load and radial stiffness, a function formula is established to achieve rapid calculation of the tire's unloaded radius, and the accuracy is verified by actual measured data.

[0016] It can be seen that compared with the prior art, the present invention has outstanding substantive features and significant progress, and the beneficial effects of its implementation are also obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 The present invention is a flow chart of a method for calculating the static load radius of a tire of an empty truck.

[0019] Figure 2 It is a schematic diagram of a calculation system of the static load radius of tires of an empty truck according to the present invention.

[0020] Figure 3 It is a schematic diagram of comparison between the calculated value of the tire unloaded radius of the type of vehicle to be inspected according to the present invention and the measured data of various tire manufacturers. DETAILED DESCRIPTION

[0021] The method for calculating the static load radius of the tire of a truck when it is empty can be applied to one or more electronic devices, wherein the electronic device is an electronic device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to a microprocessor, an application specific integrated circuit (ASIC), a programmable gate array (FPGA), a digital processor (DSP), an embedded device, etc.

[0022] An electronic device may be any electronic product that can interact with a user, such as a personal computer, a tablet computer, a smart phone, a personal digital assistant (PDA), an interactive network television (IPTV), etc. The network in which the electronic device is located includes but is not limited to the Internet, a wide area network, a metropolitan area network, a local area network, a virtual private network (VPN), etc.

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0024] See also Figure 1 The figure shows a specific implementation of a method for calculating the static load radius of a tire of an empty truck, comprising the following steps: S1. Obtain the influencing factors of the tire unloaded radius, and select the influencing factors required for calculating the tire unloaded radius according to the degree of influence of the changes of each influencing factor on the tire unloaded radius; S2. Use various influencing factors to establish a tire unloaded radius calculation formula; S3. Obtain the parameter values ​​of each influencing factor and input them into the tire unloaded radius calculation formula to obtain the calculated value of the tire unloaded radius; S4. Verify the accuracy of the calculated value of the tire unloaded radius.

[0025] In this embodiment, the specific steps of step S1 are as follows: S11. Obtaining factors affecting the tire's unloaded radius, the factors including the tire's outer diameter, static load radius, air pressure, tire load, and radial stiffness of the tire; S12. Determine the upper and lower limits of the fluctuation range of each influencing factor; S13. Identify an influencing factor; S14. Control the influencing factors of positioning to change within the upper and lower limits of the fluctuation range, and control the remaining influencing factors to remain unchanged, and measure the maximum change in the tire unloaded radius during the change of the influencing factors of positioning; S15. Identify whether the maximum change in tire unloaded radius exceeds a set change threshold; If yes, go to step S16; If not, the factors affecting positioning are taken as influencing factors; S16. Determine whether all influencing factors have been located; If yes, go to step S17; If not, locate the next influencing factor and return to step S14; S17. Determine the influencing factors obtained, wherein the influencing factors include the outer diameter of the tire, the static load radius, the air pressure, the radial stiffness, and the tire load; It should be noted that through analysis, since the vehicle tires are inflated with standard air pressure, the pressure fluctuation is generally 0% to +5%. Taking the 12R22.5 tire as an example, the pressure fluctuation is +5%, and the tire unloaded radius increases by about 1mm. Therefore, the air pressure has little effect on the tire unloaded radius, while the tire's outer diameter, static load radius, radial stiffness, tire load, etc. have a greater impact on the tire unloaded radius. The specific steps of step S2 are as follows: S21. Set the tire outer diameter d, tire standard load g1, and tire static load r in the truck tire standard. f ; S22. Set the maximum tire load g for vehicles of the same series but different models when empty max and the minimum tire load when the vehicle is empty (g) min ; S23. Calculate the radial stiffness of the tire under standard conditions and use it as the standard stiffness z1, obtain the minimum stiffness z2 of tires from different manufacturers, and then calculate the maximum load g of the tire when the vehicle is empty based on the standard stiffness z1, the minimum stiffness z2, and the maximum load g of the tire when the vehicle is empty. max and the minimum tire load when the vehicle is empty (g) min Construct an expression for the stiffness compensation coefficient k; The specific steps of step S23 are as follows: S231. Obtain the expression of the force and the displacement distance under the standard tire load; The expression of the force F is as follows: F = g1 × g Among them, F is the force, the unit is N; g1 is the standard load of the tire, the unit is kg; g is the acceleration of gravity, the unit is m / s 2 Here the gravitational acceleration is 10 m / s 2 , then the force can be expressed as F = g1×10; The expression s for the displacement distance under the standard tire load is as follows: ; S232. Construct a radial stiffness expression according to the force expression and the displacement distance expression, and calculate the radial stiffness of the tire under the standard state according to the standard tire load g1 and the displacement distance under the standard tire load to obtain the standard stiffness z1; The radial stiffness expression is as follows: Radial stiffness = force / displacement distance, unit is N / mm; The standard stiffness ; S233 obtains the stiffness of tires from different manufacturers and finds the minimum stiffness z2; S234. Maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min Calculate the tire sinking amount when the standard stiffness is z1 as the standard sinking amount; The standard sinking h1 expression is as follows: ; S235. Maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min Calculate the tire sinking amount when the minimum stiffness z2 is reached as the minimum sinking amount; The minimum sinking amount h2 is expressed as follows: ; S236. The difference between the standard sinking amount and the minimum sinking amount is used as the stiffness compensation coefficient k, and the standard stiffness z1, the minimum stiffness z2, and the maximum tire load g when the vehicle is empty are obtained. max and the minimum tire load when the vehicle is empty (g) min The expression for the stiffness coefficient k is characterized; The expression of stiffness coefficient k is as follows: ; S24. Calculate the tire sinking amount under the standard state unit load as the unit sinking amount h0; The expression of unit subsidence h0 is as follows: ; Among them, the tire outer diameter d, tire standard load g1, tire static load r f ; S25. Based on the unit sinking h0 and the actual tire load g when the vehicle is empty act Calculate the tire sinking amount h under time load when the vehicle is empty act ; ; S26. According to the actual sinking amount h act The general formula of tire unloaded radius is constructed by using the stiffness compensation coefficient k; The general formula for the tire unloaded radius is as follows: ; S27. Use the general formula for tire unloaded radius to calculate the maximum tire load (g) when the vehicle is unloaded max The corresponding minimum no-load radius rmin , and use the general formula for tire unloaded radius to calculate the minimum tire load g when the vehicle is unloaded min The corresponding maximum no-load radius r max ; Maximum no-load radius r max The expression is as follows: ; Minimum no-load radius r min The expression is as follows: ; S28. Use the maximum empty radius r max and the minimum no-load radius r min Calculate the mean value r of the tire's unloaded radius to obtain the calculation formula for the tire's unloaded radius, and then set the tolerance of the tire's unloaded radius based on the differences between different models of vehicles in the same series; the tolerance of the tire's unloaded radius is set to ±15mm;

[0026] The specific steps of step S3 are as follows: S31. Collect the minimum load of a single tire when the guide wheel of the type of vehicle to be inspected is empty as the minimum tire load when the vehicle is empty. min , and the maximum load of a single tire as the maximum tire load when the vehicle is empty g max ; S32. Compare the standard stiffness z1 with the minimum stiffness z2; If z1>z2, the stiffness coefficient k=0, and the process goes to step S33; If z1≤z2, go to step S32; S32. Based on the standard stiffness z1, minimum stiffness z2, and maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min , and use the expression of stiffness coefficient k to calculate the stiffness coefficient k; S33. Based on the tire outer diameter d, tire static load r f , Standard tire load g1, Maximum tire load when the vehicle is empty g max , Minimum tire load when empty g min和 The stiffness compensation coefficient k is used, and the tire unloaded radius calculation formula is used to calculate the tire unloaded radius mean r; S34. The tire unloaded radius mean r is introduced with a set tolerance to obtain a calculated value of the tire unloaded radius of the type of vehicle to be inspected; The specific steps of step S4 are as follows: S41. Obtain tire unloaded radius test value from tire radial stiffness test report of different tire manufacturers of vehicles of different types to be tested; S42. Verify whether the tire unloaded radius detection value of each manufacturer is within the tolerance range of the tire unloaded radius calculation value; Compare and analyze the tire radius calculated by this application with the measured data in the radial stiffness test report provided by the tire manufacturer, such as Figure 3 As described above, it can be seen that the tire data of a, b, c, d, e, and f of different tire manufacturers with the same specification are all within the upper and lower limits of the calculation, and the error between the calculated results and the measured data is within an acceptable range, which verifies the accuracy and reliability of the method; S43. Calculate the vehicle height based on the tire unloaded radius calculation value, and compare the calculated vehicle height with the vehicle height announcement value to verify the accuracy of the tire unloaded radius calculation; For example, the theoretically calculated vehicle height is 3950±20mm, which is within the range of the announced vehicle height of 3960±1%mm, thereby confirming the effectiveness and practicality of the method of the present application in actual applications.

[0027] It should be understood that the order of execution of the steps in the above embodiment does not mean that the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0028] The following is an embodiment of a system for calculating the static load radius of a tire of an empty truck provided by an embodiment of the present disclosure. This system and the systems for calculating the static load radius of a tire of an empty truck in the above-mentioned embodiments belong to the same inventive concept. For details not fully described in the embodiment of the system for calculating the static load radius of a tire of an empty truck, reference can be made to the embodiment of the method for calculating the static load radius of a tire of an empty truck in the above-mentioned embodiment.

[0029] like Figure 2 As shown, the system includes: The influencing factor screening module is used to obtain the influencing factors of the tire unloaded radius, and screen out the influencing factors required for calculating the tire unloaded radius according to the degree of influence of the changes of each influencing factor on the tire unloaded radius; A calculation formula building module is used to establish a tire unloaded radius calculation formula using various influencing factors; The no-load radius calculation module is used to obtain the parameter value of each influencing factor and input it into the tire no-load radius calculation formula to obtain the tire no-load radius calculation value; The calculation accuracy verification module is used to verify the accuracy of the calculated value of the tire unloaded radius.

[0030] The method for calculating the static load radius of the tire of a truck when it is empty provided by the present invention is a combination of the modules and algorithm steps of each example described in the embodiments disclosed herein, and can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0031] Those skilled in the art will appreciate that the various aspects of the method for calculating the static load radius of the tire of a truck when it is empty provided by the present invention can be implemented as a system, method or program product. Therefore, various aspects of the present disclosure can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software aspects, which can be collectively referred to as "circuit", "module" or "system" herein.

[0032] In the non-transitory computer-readable storage medium storing the calculation method of the static load radius of the tire when the truck is empty, it can be, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0033] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A method for calculating the static load radius of a tire of an empty truck, characterized in that: The steps include: S1. Obtain the influencing factors of the tire unloaded radius, and select the influencing factors required for calculating the tire unloaded radius according to the degree of influence of the changes of each influencing factor on the tire unloaded radius; S2. Use various influencing factors to establish a tire unloaded radius calculation formula; S3. Obtain the parameter values ​​of each influencing factor and input them into the tire unloaded radius calculation formula to obtain the calculated value of the tire unloaded radius; S4. Verify the accuracy of the calculated value of the tire unloaded radius.

2. The method for calculating the static load radius of the tire of an empty truck according to claim 1, characterized in that: The specific steps of step S1 are as follows: S11. Obtaining factors affecting the tire's unloaded radius, the factors including the tire's outer diameter, static load radius, air pressure, tire load, and radial stiffness of the tire; S12. Determine the upper and lower limits of the fluctuation range of each influencing factor; S13. Identify an influencing factor; S14. Control the influencing factors of positioning to change within the upper and lower limits of the fluctuation range, and control the remaining influencing factors to remain unchanged, and measure the maximum change in the tire unloaded radius during the change of the influencing factors of positioning; S15. Identify whether the maximum change in tire unloaded radius exceeds a set change threshold; If yes, go to step S16; If not, the factors affecting positioning are taken as influencing factors; S16. Determine whether all influencing factors have been located; If yes, go to step S17; If not, locate the next influencing factor and return to step S14; S17. Determine the obtained influencing factors, wherein the influencing factors include the outer diameter of the tire, the static load radius, the air pressure, the radial stiffness, and the tire load.

3. The method for calculating the static load radius of the tire of an empty truck according to claim 2, characterized in that: The specific steps of step S2 are as follows: S21. Set the tire outer diameter d, tire standard load g1, and tire static load r in the truck tire standard. f ; S22. Set the maximum tire load g for vehicles of the same series but different models when empty max and the minimum tire load when the vehicle is empty (g) min ; S23. Calculate the radial stiffness of the tire under standard conditions and use it as the standard stiffness z1, obtain the minimum stiffness z2 of tires from different manufacturers, and then calculate the maximum load g of the tire when the vehicle is empty based on the standard stiffness z1, the minimum stiffness z2, and the maximum load g of the tire when the vehicle is empty. max and the minimum tire load when the vehicle is empty (g) min Construct an expression for the stiffness compensation coefficient k; S24. Calculate the tire sinking amount under the standard state unit load as the unit sinking amount h0; S25. Based on the unit sinking h0 and the actual tire load g when the vehicle is empty act Calculate the tire sinking amount h under time load when the vehicle is empty act ; S26. According to the actual sinking amount h act The general formula of tire unloaded radius is constructed by using the stiffness compensation coefficient k; S27. Use the general formula for tire unloaded radius to calculate the maximum tire load (g) when the vehicle is unloaded max The corresponding minimum no-load radius r min , and use the general formula for tire unloaded radius to calculate the minimum tire load g when the vehicle is unloaded min The corresponding maximum no-load radius r max ; S28. Use the maximum empty radius r max and the minimum no-load radius r min Calculate the mean value r of the unloaded radius to obtain the calculation formula for the tire unloaded radius, and then set the tolerance of the tire unloaded radius based on the differences between different models of vehicles in the same series.

4. The method for calculating the static load radius of the tire of an empty truck according to claim 3, characterized in that: The specific steps of step S23 are as follows: S231. Obtain the expression of the force and the displacement distance under the standard tire load; S232. Construct a radial stiffness expression according to the force expression and the displacement distance expression, and calculate the radial stiffness of the tire under the standard state according to the standard tire load g1 and the displacement distance under the standard tire load to obtain the standard stiffness z1; S233 obtains the stiffness of tires from different manufacturers and finds the minimum stiffness z2; S234. Maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min Calculate the tire sinking amount when the standard stiffness is z1 as the standard sinking amount; S235. Maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min Calculate the tire sinking amount when the minimum stiffness z2 is reached as the minimum sinking amount; S236. The difference between the standard sinking amount and the minimum sinking amount is used as the stiffness compensation coefficient k, and the standard stiffness z1, the minimum stiffness z2, and the maximum tire load g when the vehicle is empty are obtained. max and the minimum tire load when the vehicle is empty (g) min Expression that characterizes the stiffness coefficient k.

5. The method for calculating the static load radius of the tire of an empty truck according to claim 3, characterized in that: The tolerance of the tire unloaded radius set in step S28 is ±15 mm.

6. The method for calculating the static load radius of the tire of an empty truck according to claim 3, characterized in that: The specific steps of step S3 are as follows: S31. Collect the minimum load of a single tire when the guide wheel of the type of vehicle to be inspected is empty as the minimum tire load when the vehicle is empty. min , and the maximum load of a single tire as the maximum tire load when the vehicle is empty g max ; S32. Compare the standard stiffness z1 with the minimum stiffness z2; If z1>z2, the stiffness coefficient k=0, and the process goes to step S33; If z1≤z2, go to step S32; S32. Based on the standard stiffness z1, minimum stiffness z2, and maximum tire load g when the vehicle is empty max and the minimum tire load when the vehicle is empty (g) min , and use the expression of stiffness coefficient k to calculate the stiffness coefficient k; S33. Based on the tire outer diameter d, tire static load r f , Standard tire load g1, Maximum tire load when the vehicle is empty g max , Minimum tire load when empty g min和 The stiffness compensation coefficient k is used, and the tire unloaded radius calculation formula is used to calculate the tire unloaded radius mean r; S34. Introducing a set tolerance into the tire unloaded radius mean r to obtain a calculated value of the tire unloaded radius of the type of vehicle to be inspected.

7. The method for calculating the static load radius of the tire of an empty truck according to claim 6, characterized in that: The specific steps of step S4 are as follows: S41. Obtain tire unloaded radius test value from tire radial stiffness test report of different tire manufacturers of vehicles of different types to be tested; S42. Verify whether the tire unloaded radius detection value of each manufacturer is within the tolerance range of the tire unloaded radius calculation value; S43. Calculate the vehicle height based on the calculated value of the tire unloaded radius, and compare the calculated vehicle height with the announced value of the vehicle height to verify the accuracy of the tire unloaded radius calculation.

8. A system for calculating the static load radius of tires of an empty truck, characterized in that: include: The influencing factor screening module is used to obtain the influencing factors of the tire unloaded radius, and screen out the influencing factors required for calculating the tire unloaded radius according to the degree of influence of the changes of each influencing factor on the tire unloaded radius; A calculation formula building module is used to establish a tire unloaded radius calculation formula using various influencing factors; The no-load radius calculation module is used to obtain the parameter value of each influencing factor and input it into the tire no-load radius calculation formula to obtain the tire no-load radius calculation value; The calculation accuracy verification module is used to verify the accuracy of the calculated value of the tire unloaded radius.

9. An electronic device, characterized in that: including a processor and a memory; The memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the electronic device executes the method described in any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores instructions, which, when executed on a computer, enable the computer to execute the method described in any one of claims 1 to 7.

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