Lifting force control method of climbing robot based on finite element simulation

Abstract

The present invention discloses a lifting force control method for a climbing robot based on finite element simulation, and the present invention relates to the technical field of engineering machinery data processing. The method comprises the following steps: The method establishes a finite element simulation model of the climbing robot to obtain the geometric characteristics of the upward transmission gear, including the number of teeth, pressure angle, root curvature radius, root height, tooth width and material characteristics such as elastic modulus and Poisson's ratio. The gear operation under load is simulated, and the torque data is obtained to determine the modulus and calculate the root stress. The root stress is corrected in combination with the vibration characteristics and the surface temperature to obtain an accurate value. The roughness is calculated by the surface height difference, and the friction coefficient is corrected in combination with the ambient humidity and the inclination angle to calculate the friction force. Finally, the real-time lifting force control coefficient is calculated according to the friction force, the precise root stress and the gravity, and the lifting force is dynamically corrected to achieve accurate control of the lifting force of the climbing robot.

Description

Technical Field

[0001] The invention relates to the technical field of engineering machinery data processing, and in particular to a climbing robot lifting force control method based on finite element simulation. Background Art

[0002] Climbing robots have become an important tool in modern industry and infrastructure maintenance, especially in high-risk environments such as the inspection and maintenance of transmission towers. These robots can effectively reduce manpower requirements and risks. However, the complex structure and environmental conditions of transmission towers pose severe challenges to the design and control of climbing robots. Traditional climbing robot control methods mainly rely on preset fixed parameters and simple physical models to calculate the lifting force. However, these methods often appear to be unable to cope with complex environmental changes, such as different surface roughness, ambient humidity, and tilt angles. This leads to problems such as excessive energy consumption, unstable climbing, and even failure of climbing robots during operation, which seriously affects the efficiency and safety of work.

[0003] Finite element analysis (FEA) is a powerful simulation tool that can simulate the stress and deformation of complex structures under different loads and boundary conditions. By performing finite element simulation on climbing robots, especially their key components such as the upward transmission gear, we can more accurately understand their mechanical behavior in the actual operating environment. This technology can provide detailed stress distribution, deformation patterns, and potential failure forms, allowing us to better optimize the design and control strategy. However, although finite element simulation can provide accurate models in theory, in practice, how to effectively combine simulation results with real-time control strategies is still a problem that needs to be solved.

[0004] In addition, the influence of the surface characteristics (such as roughness) of the transmission tower and environmental conditions (such as humidity and temperature) on the friction coefficient also brings additional complexity to the precise control of the lifting force. Traditional methods often ignore the combined influence of these nonlinear factors, resulting in inflexible control strategies that cannot adapt to the dynamically changing actual environment. Therefore, developing a lifting force control method for climbing robots based on finite element simulation to dynamically adapt to complex environmental changes has become an important topic in the current technical field.

[0005] In the prior art, the publication number CN114139419B discloses a method for calculating the lifting force and horizontal force of a belt conveyor based on finite element simulation. By considering the influence of the track itself, the influence of the bracket stiffness on the lifting force and horizontal force is also considered by creating a bracket finite element model. The stress distribution of the belt conveyor bracket, sleeper and track can be effectively evaluated: the bracket, sleeper and track are actually created through the finite element model, and the effective combination of load conditions can analyze the stress situation under the combined action of the lifting force and horizontal force. The lifting force and horizontal force required for the belt conveyor to be relocated can be easily calculated to achieve rapid selection of the relocation machine, and the stress distribution of the belt conveyor bracket, sleeper and track can be effectively evaluated to achieve structural optimization design. However, in this scheme, in actual applications, the model may ignore some actual situations, such as nonlinear behavior of materials, contact mechanics, dynamic effects, etc. These assumptions may lead to insufficient adaptability of the model to complex working conditions. At the same time, during operation, it will be affected by dynamic loads, such as vibration loads, etc., and relying solely on static models may not accurately predict the mechanical behavior under dynamic conditions. At the same time, the impact of environmental factors is not taken into account, which reduces the accuracy and effectiveness of regulatory information.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0007] The purpose of the present invention is to provide a climbing robot lifting force control method based on finite element simulation to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A climbing robot lifting force control method based on finite element simulation, the specific steps include:

[0010] Collecting geometric characteristic parameters of the climbing robot's upward transmission gear, establishing a finite element simulation model of the climbing robot based on the geometric characteristic parameters, obtaining material characteristic parameters of the climbing robot's upward transmission gear, and inputting the material characteristic parameters into the finite element simulation model, wherein the geometric characteristic parameters of the upward transmission gear include the number of teeth, pressure angle, tooth root curvature radius, tooth root height and tooth width, and the material characteristic parameters include elastic modulus and Poisson's ratio;

[0011] Based on the finite element simulation model of the climbing robot, the operation of the upward transmission gear of the climbing robot under load is simulated to obtain the torque data of the upward transmission gear. The modulus of the upward transmission gear is determined by combining the torque data with the geometric characteristic parameters of the upward transmission gear.

[0012] Based on the determined modulus of the upward transmission gear, the tooth root stress of the upward transmission gear is calculated, and at the same time, the vibration characteristic parameters of the upward transmission gear when the climbing robot is running are collected, and the vibration load is calculated based on the vibration characteristic parameters. According to the vibration load and the surface temperature of the transmission gear, the tooth root stress is corrected to obtain the accurate tooth root stress, and the vibration characteristic parameters include vibration amplitude and vibration frequency;

[0013] The surface roughness of the climbed device is obtained based on the surface roughness measuring equipment. The friction coefficient is corrected by combining the surface roughness with the ambient humidity and the climbing inclination angle to obtain the precise friction coefficient, and the friction force is calculated based on the precise friction coefficient.

[0014] According to the friction force, precise tooth root stress and the load's own gravity, the real-time lifting force control coefficient of the climbing robot is calculated. The currently applied lifting force is corrected by the real-time lifting force control coefficient to complete the dynamic control of the climbing robot's lifting force.

[0015] Furthermore, a finite element simulation model is established, which specifically includes the following steps: determining the shape structure of the uplink transmission gear according to the geometric characteristic parameters of the uplink transmission gear; creating a finite element simulation model of the climbing robot in combination with the other surface parameters of the climbing robot, meshing the gear model, selecting the mesh unit type and size, and ensuring that the mesh density is highest in the root area of ​​the gear; defining the material properties of the uplink transmission gear, including elastic modulus and Poisson's ratio, which are used to obtain the initial friction coefficient based on the material property parameters.

[0016] Furthermore, based on the finite element simulation model of the climbing robot, the operation of the upward transmission gear of the climbing robot under load is simulated to obtain the torque data of the upward transmission gear. Specifically, in the simulation, the grid force in the gear contact area is extracted, the distribution of the grid force is analyzed, and the effective torque received by the upward transmission gear is obtained, and the effective torque is used as the torque of the upward transmission gear.

[0017] The modulus of the upward transmission gear is determined by combining the torque data with the geometric characteristic parameters of the upward transmission gear. The formula for calculating the modulus of the upward transmission gear is:

[0018] ;

[0019] In the formula, is the module of the upward transmission gear, is the torque on the transmission gear, is the number of teeth of the upward transmission gear, is the tooth width coefficient, is the allowable bending stress;

[0020] The tooth width coefficient The calculation is based on the formula:

[0021] ;

[0022] In the formula, is the tooth width of the upward transmission gear.

[0023] Further, based on the determined module of the upward transmission gear, the tooth root stress of the upward transmission gear is calculated, wherein the formula for calculating the tooth root stress of the upward transmission gear is:

[0024] ;

[0025] In the formula, is the tooth root stress of the upward transmission gear, is the load gravity, is the tooth shape coefficient when the load acts on the tooth top, is the stress correction factor when the load acts on the tooth top, The coincidence factor calculated for flexural strength;

[0026] The formula for calculating load gravity is:

[0027] ;

[0028] In the formula, is the weight of the climbing robot equipment, is the load weight, is the acceleration due to gravity;

[0029] Tooth shape coefficient when the load acts on the tooth top The calculation is based on the formula:

[0030] ;

[0031] In the formula, is the pressure angle of the upward transmission gear;

[0032] Stress correction factor when the load acts on the tooth top The specific expression formula is:

[0033] ;

[0034] In the formula, is the tooth root height of the upward transmission gear, is the root curvature radius of the upward transmission gear;

[0035] The formula for calculating the overlap coefficient of the bending strength calculation is:

[0036] ;

[0037] in, is the end face overlap of the equivalent gear, and the specific formula is:

[0038] ;

[0039] In the formula, is the axial contact of the gears, is the helix angle of the gear.

[0040] Furthermore, the vibration characteristic parameters of the upward transmission gear of the climbing robot are collected at the same time when the climbing robot is running, and the vibration load is calculated based on the vibration characteristic parameters, wherein the specific formula for calculating the vibration load is:

[0041] ;

[0042] In the formula, is the vibration load at time t, is the vibration acceleration at time t, where the formula for calculating the vibration acceleration is:

[0043] ;

[0044] In the formula, is the vibration amplitude of the whole mechanism at time t during the climbing process of the climbing robot, is the vibration frequency of the whole mechanism at time t during the climbing process of the climbing robot, and t is the time variable during the climbing process of the climbing robot;

[0045] The vibration load is calculated based on the vibration characteristic parameters. According to the vibration load and the surface temperature of the transmission gear, the tooth root stress is corrected to obtain the accurate tooth root stress. The specific formula for obtaining the accurate tooth root stress is:

[0046] ;

[0047] In the formula, is the exact tooth root stress at time t, is the surface temperature of the transmission gear at time t, is the reference temperature of the transmission gear surface, and are the weight coefficients of the transmission gear surface temperature and vibration load, respectively, where and and Both are greater than 0.

[0048] Furthermore, the surface roughness measuring device uses a stylus profilometer, randomly selects multiple sampling areas from the surface of the climbed device used for climbing by the climbing robot, uses the stylus profilometer to measure and analyze the sampling areas to obtain the surface roughness of each sampling area, and calculates the average surface roughness of all sampling areas, and uses this average as the surface roughness of the climbed device. The calculation formula is as follows:

[0049] ;

[0050] ;

[0051] In the formula, represents the sampling length of the stylus profilometer in the kth sampling area, k is the index of the sampling area, and , K is the number of sampling areas, is the height of the x-th sampling point within the sampling length of the k-th sampling area from the center line, x is the coordinate of the sampling point within the sampling length, is the surface roughness of the kth sampling area, is the surface roughness of the climbing device, the center line and The data is obtained by processing the built-in software of the stylus profilometer;

[0052] The friction coefficient is corrected by combining the surface roughness, ambient humidity and climbing inclination angle to obtain the precise friction coefficient. The friction force is calculated based on the precise friction coefficient. The formula for calculating the precise friction coefficient is:

[0053] ;

[0054] In the formula, represents the exact friction coefficient at time t, is the initial friction coefficient, is the ambient humidity at time t, Tilt angle for climbing;

[0055] The friction force is calculated based on the exact friction coefficient, where the friction force is calculated based on the formula:

[0056] ;

[0057] In the formula, is the friction force at time t, and They represent the climbing robot equipment weight and load weight respectively.

[0058] Furthermore, according to the friction force, the precise tooth root stress and the load's own gravity, the real-time lifting force control coefficient of the climbing robot is calculated, wherein the formula for calculating the real-time lifting force control coefficient of the climbing robot is:

[0059] ;

[0060] In the formula, is the lifting force control coefficient of the climbing robot at time t, is the exact tooth root stress at time t, represents the load gravity, is the set tooth root stress threshold, where , and are the weight coefficients of precise tooth root stress, friction force and load gravity, and , and Both are greater than 0.

[0061] Furthermore, the currently applied lifting force is corrected by the real-time lifting force control coefficient, wherein the specific lifting force correction formula is:

[0062] ;

[0063] In the formula, for The climbing robot's lifting force at all times, is the lifting force applied at time t.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] Firstly, an accurate finite element model was established by collecting the geometric and material characteristics of the climbing robot's uplink transmission gear. The model can truly reproduce the mechanical behavior of the gear under different load conditions, providing a reliable theoretical basis for the optimization of lifting force. Secondly, the torque data and tooth root stress of the uplink transmission gear were obtained through the computational analysis of the simulation model. On this basis, the tooth root stress was dynamically corrected in combination with the real-time collected vibration characteristic parameters and surface temperature. The accuracy of the tooth root stress calculation was improved, and more reliable basic data was provided for lifting force control. In addition, the dynamic changes of the surface characteristics of the transmission tower were also considered. The surface roughness was calculated by accurately measuring the height difference of the sample length of the climbing surface, and the friction coefficient was corrected in combination with the ambient humidity and the climbing inclination angle. Such processing ensures the accuracy of the friction calculation, enabling the climbing robot to maintain a stable climbing state in a complex and changing environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION

[0067] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0068] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0069] Example:

[0070] See also Figure 1 , the present invention provides a technical solution:

[0071] A climbing robot lifting force control method based on finite element simulation, the specific steps include:

[0072] Step 1: Collect the geometric characteristic parameters of the climbing robot's up transmission gear, establish a finite element simulation model of the climbing robot based on the geometric characteristic parameters, obtain the material characteristic parameters of the climbing robot's up transmission gear, and input the material characteristic parameters into the finite element simulation model. The geometric characteristic parameters of the up transmission gear include the number of teeth, pressure angle, tooth root curvature radius, tooth root height and tooth width, and the material characteristic parameters include elastic modulus and Poisson's ratio.

[0073] Measure the total number of teeth on the gear. The number of teeth affects the transmission ratio and meshing characteristics of the gear. Use an angle measuring tool or a gear gauge to measure the pressure angle of the gear, which is an important parameter of the gear tooth profile and affects the meshing efficiency. Measure the width of the gear teeth. Usually use a caliper or a coordinate measuring machine (CMM) to obtain accurate data. The root curvature radius and root height are often obtained according to the gear standardized design manual. Many gear manufacturers or standardization organizations (such as AGMA, ISO, etc.) provide special calculation tools and data tables to help designers obtain parameters such as the root curvature radius and root height.

[0074] A finite element simulation model is established, and the specific steps included are: determining the shape structure of the uplink transmission gear according to the geometric characteristic parameters of the uplink transmission gear; creating a finite element simulation model of the climbing robot in combination with the remaining surface parameters of the climbing robot, meshing the gear model, selecting the mesh unit type and size, and ensuring that the mesh density is highest in the root area of ​​the gear; defining the material properties of the uplink transmission gear, including elastic modulus and Poisson's ratio, for obtaining the initial friction coefficient according to the material property parameters, wherein the remaining surface parameters of the climbing robot include characteristic parameters of the overall structure of the climbing robot, such as overall size, shape, etc.

[0075] Use CAD software (such as SolidWorks, AutoCAD or Fusion 360) to create a 3D model of the gear based on the measured geometric parameters. Import the created CAD model into finite element analysis software (such as ANSYS, Abaqus or COMSOL). Mesh the gear model. Choose the appropriate element type and size, and ensure a high mesh density in critical areas of the gear (such as the tooth root and meshing area) to improve the accuracy of the analysis. The elastic modulus and Poisson's ratio can usually be obtained from the technical specifications provided by the material supplier or determined by laboratory material testing. In the finite element software, define the material properties of the gear and enter the elastic modulus and Poisson's ratio. These parameters will be used to simulate the elastic behavior of the material under load.

[0076] Step 2: Based on the finite element simulation model of the climbing robot, simulate the operation of the upward transmission gear of the climbing robot under load, obtain the torque data of the upward transmission gear, and determine the modulus of the upward transmission gear through the torque data combined with the geometric characteristic parameters of the upward transmission gear.

[0077] Based on the finite element simulation model of the climbing robot, the operation of the upward transmission gear of the climbing robot under load is simulated to obtain the torque data of the upward transmission gear. Specifically, in the simulation, the grid force in the gear contact area is extracted, the distribution of the grid force is analyzed, and the effective torque on the upward transmission gear is obtained. The effective torque is used as the torque of the upward transmission gear.

[0078] The modulus of the upward transmission gear is determined by combining the torque data with the geometric characteristic parameters of the upward transmission gear. The formula for calculating the modulus of the upward transmission gear is:

[0079] ;

[0080] In the formula, is the module of the upward transmission gear, is the torque on the transmission gear, is the number of teeth of the upward transmission gear, is the tooth width coefficient, is the allowable bending stress;

[0081] The allowable bending stress It is determined by the foundation allowable bending stress and the working environment, and the specific formula is:

[0082] ;

[0083] In the formula, For the basic allowable bending stress, refer to the data in some engineering material manuals or standard manuals. These manuals usually provide recommended values ​​of bending strength, yield strength and allowable stress for different materials (such as steel, aluminum, concrete, etc.). is the temperature correction constant, is the surface temperature of the transmission gear at time t, The reference temperature of the transmission gear surface is generally 25 Up to 40 , where the temperature correction constant is The accuracy can be obtained by referring to the experience manual, and the general range is between 0.02 and 0.1.

[0084] The tooth width coefficient The calculation is based on the formula:

[0085] ;

[0086] In the formula, is the tooth width of the upward transmission gear.

[0087] Step 3: Based on the determined modulus of the upward transmission gear, the tooth root stress of the upward transmission gear is calculated, and at the same time, the vibration characteristic parameters of the upward transmission gear when the climbing robot is running are collected, and the vibration load is calculated based on the vibration characteristic parameters. According to the vibration load and the surface temperature of the transmission gear, the tooth root stress is corrected to obtain the accurate tooth root stress. The vibration characteristic parameters include vibration amplitude and vibration frequency.

[0088] Based on the determined module of the uplink transmission gear, the tooth root stress of the uplink transmission gear is calculated, wherein the formula for calculating the tooth root stress of the uplink transmission gear is:

[0089] ;

[0090] In the formula, is the tooth root stress of the upward transmission gear, is the load gravity, is the tooth shape coefficient when the load acts on the tooth top, is the stress correction factor when the load acts on the tooth top, The coincidence factor calculated for flexural strength;

[0091] The formula for calculating load gravity is:

[0092] ;

[0093] In the formula, is the weight of the climbing robot equipment, is the load weight, is the acceleration due to gravity;

[0094] Tooth shape coefficient when the load acts on the tooth top The calculation is based on the formula:

[0095] ;

[0096] In the formula, is the pressure angle of the upward transmission gear;

[0097] Stress correction factor when the load acts on the tooth top The specific expression formula is:

[0098] ;

[0099] In the formula, is the tooth root height of the upward transmission gear, is the root curvature radius of the upward transmission gear;

[0100] The radius of curvature is increased It reduces stress concentration because it distributes the stress more evenly. A larger radius of curvature means a larger arc transition at the root of the tooth, which helps to reduce the stress concentration effect. Increasing the root height can enhance the overall strength of the gear because it provides more material to bear the applied load. A larger root height also helps to reduce the stress concentration effect, so the radius of curvature and root height are Indicates the stress correction factor when the load acts on the tooth top Inversely proportional;

[0101] Wider tooth surfaces can better distribute stress because a larger contact area can reduce the stress per unit area, so the tooth width Stress correction factor when the load acts on the tooth top Inversely proportional, through Reflects the ratio of the tooth width to the module. A higher ratio indicates that the width of the tooth is larger relative to the other dimensions, which generally helps reduce stress concentrations.

[0102] The formula for calculating the overlap coefficient of the bending strength calculation is:

[0103] ;

[0104] in, is the end face overlap of the equivalent gear, and the specific formula is:

[0105] ;

[0106] In the formula, is the axial contact of the gears, is the helix angle of the gear.

[0107] The helix angle It is the inclination angle of the gear tooth line relative to the gear axis. Usually, this angle is determined during gear design and manufacturing and can be directly obtained from the gear design drawings or technical specifications. It refers to the number of teeth or tooth length meshing along the axial direction of the gear during the gear meshing process. It can be calculated by the circular pitch of the gear (the tooth pitch along the meshing direction). The specific calculation method is a conventional technical means and will not be elaborated here.

[0108] At the same time, the vibration characteristic parameters of the upward transmission gear when the climbing robot is running are collected, and the vibration load is calculated based on the vibration characteristic parameters. The specific formula for calculating the vibration load is:

[0109] ;

[0110] In the formula, is the vibration load at time t, is the vibration acceleration at time t, where the formula for calculating the vibration acceleration is:

[0111] ;

[0112] In the formula, is the vibration amplitude of the whole mechanism at time t during the climbing process of the climbing robot, is the vibration frequency of the whole mechanism at time t during the climbing process of the climbing robot, and t is the time variable during the climbing process of the climbing robot.

[0113] The vibration load is calculated based on the vibration characteristic parameters. According to the vibration load and the surface temperature of the transmission gear, the tooth root stress is corrected to obtain the accurate tooth root stress. The specific formula for obtaining the accurate tooth root stress is:

[0114] ;

[0115] In the formula, is the exact tooth root stress at time t, is the surface temperature of the transmission gear at time t, is the reference temperature of the transmission gear surface, and are the weight coefficients of the transmission gear surface temperature and vibration load, respectively, where and and Both are greater than 0.

[0116] Among them, greater vibration and shock loads, which can cause stress concentration and fatigue, is the vibration load at time t. The larger its value is, the greater the vibration amplitude and vibration frequency is. and Proportional, through The nonlinear effect of vibration load on the precise tooth root stress is described, indicating that when the vibration load increases to a certain extent, the effect on the precise tooth root stress gradually weakens.

[0117] High temperature may reduce the strength of the material, causing the root stress to increase under the same load. Under high temperature conditions, the yield strength of the material usually decreases. This means that the material will undergo plastic deformation under lower stress conditions. Therefore, under the same load, the gear is more likely to deform or be damaged. The hardness and toughness of the material at high temperature may decrease, affecting the ability to resist fatigue and vibration loads. This change will increase the possibility of cracks or fractures in the root area during operation. Therefore, the surface temperature of the transmission gear is proportional to the precise root stress, which can be measured by Indicates the significant effect of temperature on the exact tooth root stress when the surface temperature exceeds the reference temperature.

[0118] Since vibration is inevitable during movement and has a direct impact on the precise tooth root stress, the setting and and Both are greater than 0.

[0119] Step 4: Obtain the surface roughness of the climbed device based on the surface roughness measuring equipment, correct the friction coefficient through the surface roughness, combined with the ambient humidity and the climbing inclination angle, obtain the precise friction coefficient, and calculate the friction force based on the precise friction coefficient.

[0120] The surface roughness measuring device uses a stylus profilometer, randomly selects multiple sampling areas from the surface of the climbed device used for climbing by the climbing robot, uses the stylus profilometer to measure and analyze the sampling areas to obtain the surface roughness of each sampling area, and calculates the average surface roughness of all sampling areas. This average is used as the surface roughness of the climbed device. The calculation formula is as follows:

[0121] ;

[0122] ;

[0123] In the formula, represents the sampling length of the stylus profilometer in the kth sampling area, k is the index of the sampling area, and , K is the number of sampling areas, is the height of the x-th sampling point within the sampling length of the k-th sampling area from the center line, x is the coordinate of the sampling point within the sampling length, is the surface roughness of the kth sampling area, is the surface roughness of the climbing device, the center line and The data is obtained through the built-in software of the stylus profilometer.

[0124] The friction coefficient is corrected by combining the surface roughness, ambient humidity and climbing inclination angle to obtain the precise friction coefficient. The friction force is calculated based on the precise friction coefficient. The formula for calculating the precise friction coefficient is:

[0125] ;

[0126] In the formula, represents the exact friction coefficient at time t, is the initial friction coefficient, is the ambient humidity at time t, Tilt angle for climbing;

[0127] The surface roughness has a significant effect on the friction coefficient. Rough surfaces generally increase friction, so the surface roughness of the climbing device is proportional to the exact friction coefficient, but too rough a surface may cause unstable sliding. A logarithmic function can be used to smooth out this effect.

[0128] Humidity can change the adhesion characteristics of the contact surface and affect the friction coefficient. Increased humidity may lead to a lubrication effect, which reduces the friction coefficient. Therefore, the ambient humidity is inversely proportional to the exact friction coefficient, which will be set in the denominator to represent the inverse relationship.

[0129] The tilt angle affects the distribution of the normal force and thus the friction. A nonlinear trigonometric function (such as the tangent function) Used to express the effect of inclination angle on the friction coefficient.

[0130] The friction force is calculated based on the exact friction coefficient, where the friction force is calculated based on the formula:

[0131] ;

[0132] In the formula, is the friction force at time t, and They represent the climbing robot equipment weight and load weight respectively.

[0133] Step 5: Based on the friction force, precise tooth root stress and the load's own gravity, the real-time lifting force control coefficient of the climbing robot is calculated. The currently applied lifting force is corrected by the real-time lifting force control coefficient to complete the dynamic control of the climbing robot's lifting force.

[0134] According to the friction force, precise tooth root stress and the load's own gravity, the real-time lifting force control coefficient of the climbing robot is calculated. The formula for calculating the real-time lifting force control coefficient of the climbing robot is:

[0135] ;

[0136] In the formula, is the lifting force control coefficient of the climbing robot at time t, is the exact tooth root stress at time t, represents the load gravity, is the set tooth root stress threshold, where , and are the weight coefficients of precise tooth root stress, friction force and load gravity, and , and Both are greater than 0.

[0137] The currently applied lifting force is corrected by the real-time lifting force control coefficient, wherein the specific lifting force correction formula is:

[0138] ;

[0139] In the formula, for The climbing robot's lifting force at all times, is the lifting force applied at time t.

[0140] By setting the tooth root stress threshold Indicates when Exceed After that, the lifting force control coefficient If it is a negative number, the lifting force should be reduced to ensure safety. The tooth root stress threshold It can be set according to the characteristic parameters of the material combined with expert experience.

[0141] At the same time, the greater the friction and load gravity, the greater the lifting force should be to ensure that the climbing robot can complete the rising work requirements. and Make the lifting force control coefficient increase more smoothly.

[0142] Since the precise tooth root stress is related to safety, the weight coefficient of the precise tooth root stress is the largest. At the same time, since the load gravity changes less during the ascent stage and can generally be determined at the start, the weight coefficient of the load gravity is the smallest. The final setting is and , and Both are greater than 0.

[0143] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0144] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0145] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0146] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A climbing robot lifting force control method based on finite element simulation, characterized in that: The specific steps include: Collecting geometric characteristic parameters of the climbing robot's upward transmission gear, establishing a finite element simulation model of the climbing robot based on the geometric characteristic parameters, obtaining material characteristic parameters of the climbing robot's upward transmission gear, and inputting the material characteristic parameters into the finite element simulation model, wherein the geometric characteristic parameters of the upward transmission gear include the number of teeth, pressure angle, tooth root curvature radius, tooth root height and tooth width, and the material characteristic parameters include elastic modulus and Poisson's ratio; Based on the finite element simulation model of the climbing robot, the operation of the upward transmission gear of the climbing robot under load is simulated to obtain the torque data of the upward transmission gear. The modulus of the upward transmission gear is determined by combining the torque data with the geometric characteristic parameters of the upward transmission gear. Based on the determined modulus of the upward transmission gear, the tooth root stress of the upward transmission gear is calculated, and at the same time, the vibration characteristic parameters of the upward transmission gear when the climbing robot is running are collected, and the vibration load is calculated based on the vibration characteristic parameters. According to the vibration load and the surface temperature of the transmission gear, the tooth root stress is corrected to obtain the accurate tooth root stress, and the vibration characteristic parameters include vibration amplitude and vibration frequency; The surface roughness of the climbed device is obtained based on the surface roughness measuring equipment. The friction coefficient is corrected by combining the surface roughness with the ambient humidity and the climbing inclination angle to obtain the precise friction coefficient, and the friction force is calculated based on the precise friction coefficient. The surface roughness measuring device uses a stylus profilometer, randomly selects multiple sampling areas from the surface of the climbed device used for climbing by the climbing robot, uses the stylus profilometer to measure and analyze the sampling areas to obtain the surface roughness of each sampling area, and calculates the average surface roughness of all sampling areas. This average is used as the surface roughness of the climbed device. The calculation formula is as follows: Where, L k represents the sampling length of the stylus profilometer in the kth sampling area, k is the index of the sampling area, and k∈[1,K], K is the number of sampling areas, D(x) k is the height of the x-th sampling point within the sampling length of the k-th sampling area from the center line, x is the coordinate of the sampling point within the sampling length, Ra k is the surface roughness of the kth sampling area, Ra is the surface roughness of the climbing device, the center line and D(x) k The data is obtained by processing the built-in software of the stylus profilometer; The friction coefficient is corrected by combining the surface roughness, ambient humidity and climbing inclination angle to obtain the precise friction coefficient. The friction force is calculated based on the precise friction coefficient. The formula for calculating the precise friction coefficient is: Where μ′(t) represents the exact friction coefficient at time t, μ0 is the initial friction coefficient, RH(t) is the ambient humidity at time t, and θ is the climbing inclination angle; The friction force is calculated based on the exact friction coefficient, where the friction force is calculated based on the formula: F fri (t)=μ′(t)*(M1+M2) In the formula, F fri (t) is the friction force at time t, M1 and M2 represent the weight of the climbing robot equipment and the load weight, respectively; According to the friction force, precise tooth root stress and the load's own gravity, the real-time lifting force control coefficient of the climbing robot is calculated, and the currently applied lifting force is corrected by the real-time lifting force control coefficient to complete the dynamic control of the climbing robot's lifting force; According to the friction force, precise tooth root stress and the load's own gravity, the real-time lifting force control coefficient of the climbing robot is calculated. The formula for calculating the real-time lifting force control coefficient of the climbing robot is: Where XS(t) is the lifting force control coefficient of the climbing robot at time t, σ F0 ′(t) is the exact tooth root stress at time t, F M represents the load gravity, yz is the set tooth root stress threshold, where ω1, ω2 and ω3 are the weight coefficients of the precise tooth root stress, friction force and load gravity, respectively, ω1≥ω2>ω3 and ω1, ω2 and ω3 are all greater than 0.

2. The method for controlling the lifting force of a climbing robot based on finite element simulation according to claim 1 is characterized in that: A finite element simulation model is established, and the specific steps included are: determining the shape structure of the uplink transmission gear according to the geometric characteristic parameters of the uplink transmission gear; creating a finite element simulation model of the climbing robot in combination with the other surface parameters of the climbing robot, meshing the gear model, selecting the mesh unit type and size, and ensuring that the mesh density is highest in the root area of ​​the gear; defining the material properties of the uplink transmission gear, including elastic modulus and Poisson's ratio, which are used to obtain the initial friction coefficient according to the material property parameters.

3. The method for controlling the lifting force of a climbing robot based on finite element simulation according to claim 2 is characterized in that: Based on the finite element simulation model of the climbing robot, the operation of the upward transmission gear of the climbing robot under load is simulated to obtain the torque data of the upward transmission gear. Specifically, in the simulation, the grid force in the gear contact area is extracted, the distribution of the grid force is analyzed, and the effective torque on the upward transmission gear is obtained. The effective torque is used as the torque of the upward transmission gear. The modulus of the upward transmission gear is determined by combining the torque data with the geometric characteristic parameters of the upward transmission gear. The formula for calculating the modulus of the upward transmission gear is: In the formula, m is the module of the upward transmission gear, G is the torque on the transmission gear, and Z is the number of teeth of the upward transmission gear. is the tooth width coefficient, σ F is the allowable bending stress; The tooth width coefficient The calculation is based on the formula: Where b is the tooth width of the upward transmission gear.

4. The method for controlling the lifting force of a climbing robot based on finite element simulation according to claim 3 is characterized in that: Based on the determined module of the uplink transmission gear, the tooth root stress of the uplink transmission gear is calculated, wherein the formula for calculating the tooth root stress of the uplink transmission gear is: In the formula, σ F0 is the tooth root stress of the upward transmission gear, F M is the load gravity, Y Fa Y is the tooth shape coefficient when the load acts on the tooth top, Sa is the stress correction factor when the load acts on the tooth top, Y ε The coincidence factor calculated for flexural strength; The formula for calculating load gravity is: F M =(m1+m2)*g In the formula, m1 is the weight of the climbing robot equipment, m2 is the load weight, and g is the acceleration of gravity; When the load acts on the tooth top, the tooth shape coefficient Y Fa The calculation is based on the formula: Where α is the pressure angle of the upward transmission gear; The stress correction factor Y when the load acts on the tooth top Sa The specific expression formula is: Where h is the tooth root height of the upward transmission gear, and ρ is the tooth root curvature radius of the upward transmission gear; The formula for calculating the overlap coefficient of the bending strength calculation is: Among them, ε an is the end face overlap of the equivalent gear, and the specific formula is: In the formula, ε a is the axial contact of the gear, β c is the helix angle of the gear.

5. The method for controlling the lifting force of a climbing robot based on finite element simulation according to claim 4 is characterized in that: At the same time, the vibration characteristic parameters of the upward transmission gear when the climbing robot is running are collected, and the vibration load is calculated based on the vibration characteristic parameters. The specific formula for calculating the vibration load is: F dyn (t)=(M1+M2)*a rms (t) In the formula, F dyn (t) is the vibration load at time t, a rms (t) is the vibration acceleration at time t, where the formula for calculating the vibration acceleration is: a rms (t)=A(t)*{2πf(t)} 2 *cos(2πf(t)) Where A(t) is the vibration amplitude of the whole mechanism at time t during the climbing process of the climbing robot, f(t) is the vibration frequency of the whole mechanism at time t during the climbing process of the climbing robot, and t is the time variable during the climbing process of the climbing robot; The vibration load is calculated based on the vibration characteristic parameters. According to the vibration load and the surface temperature of the transmission gear, the tooth root stress is corrected to obtain the accurate tooth root stress. The specific formula for obtaining the accurate tooth root stress is: where, σ F0 ′(t) is the exact tooth root stress at time t, T(t) is the surface temperature of the transmission gear at time t, T0 is the reference surface temperature of the transmission gear, and k1 and k2 are the weight coefficients of the surface temperature and vibration load of the transmission gear, respectively, where k1 < k2 and both k1 and k2 are greater than 0.

6. The method for controlling the lifting force of a climbing robot based on finite element simulation according to claim 5 is characterized in that: The currently applied lifting force is corrected by the real-time lifting force control coefficient, wherein the specific lifting force correction formula is: F ts (t+1)=F ts (t)*(1+XS(t)) In the formula, F ts (t+1) is the lifting force of the climbing robot at time t+1, F ts (t) is the lifting force applied at time t.

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