NW type compound planetary gear train transmission efficiency optimization method and device based on intelligent optimization, electronic equipment and storage medium

Abstract

The invention provides an NW type compound planetary gear train transmission efficiency optimization method and device based on intelligent optimization, electronic equipment and a storage medium. The method comprises the steps that multiple sets of initial tooth profile modification parameters are obtained, and the initial tooth profile modification parameters are used for modifying a gear in an NW type compound planetary gear train; according to the multiple sets of initial tooth profile modification parameters, calculation is carried out, the fitness value of each set of initial tooth profile modification parameters is obtained, and the fitness values are used for representing the quality degree of the corresponding initial tooth profile modification parameters; the multiple sets of initial tooth profile modification parameters are subjected to iterative calculation through an intelligent optimization algorithm, target tooth profile modification parameters are obtained, the target tooth profile modification parameters are tooth profile modification parameters meeting preset conditions, the intelligent optimization algorithm comprises a multi-target genetic algorithm, and the preset conditions are used for indicating the transmission efficiency and friction loss of the gear; and adjusting the tooth profile of the gear in the NW type compound planetary gear train by adopting the target tooth profile modification parameter. The transmission efficiency of the NW type compound planetary gear train can be improved.

Description

Technical Field

[0001] The present application relates to the field of mechanics, and in particular to a method, device, electronic device and storage medium for optimizing the transmission efficiency of a NW-type composite planetary gear train based on intelligent optimization. Background Art

[0002] The NW type compound planetary gear train has the phenomenon of alternating single and double teeth meshing, which causes a sudden change in the load distribution of the gears at different time points, easily leading to local stress concentration and increased impact load, thereby affecting the transmission smoothness and gear life. When the traditional power method calculates the gear transmission efficiency, it is usually assumed that the load distribution is uniform, and the problem of sudden load changes in actual operation is not fully considered. Therefore, when designing the tooth shape of the NW type compound planetary gear train, it is impossible to perform targeted optimization according to the meshing characteristics of the NW type compound planetary gear train, resulting in a low transmission efficiency of the NW type compound planetary gear train. Summary of the invention

[0003] The main purpose of the embodiments of the present application is to propose a method, device, electronic device and storage medium for optimizing the transmission efficiency of a NW type compound planetary gear train based on intelligent optimization, aiming to solve the problem of low transmission efficiency of the existing NW type compound planetary gear train.

[0004] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application proposes a method for optimizing the transmission efficiency of a NW type compound planetary gear train based on intelligent optimization, the method comprising: Acquire multiple sets of initial tooth profile modification parameters, where the initial tooth profile modification parameters are used to modify the gears in the NW type compound planetary gear train; Calculating according to the multiple groups of initial tooth profile modification parameters to obtain a fitness value of each group of initial tooth profile modification parameters, wherein the fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters; Iteratively calculating multiple groups of the initial tooth profile modification parameters through an intelligent optimization algorithm to obtain target tooth profile modification parameters, wherein the target tooth profile modification parameters are tooth profile modification parameters that meet preset conditions, wherein the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the preset conditions are used to indicate the transmission efficiency and friction loss of the gear; The target tooth profile modification parameters are used to adjust the tooth profile of the gear in the NW type compound planetary gear train.

[0005] In some embodiments, the calculation is performed based on the multiple groups of initial tooth profile modification parameters to obtain the fitness value of each group of initial tooth profile modification parameters, including: Calculate each group of the initial tooth profile modification parameters by using a rolling friction force calculation equation to obtain the friction loss of each group of the tooth profile modification parameters, wherein the rolling friction force calculation equation is used to calculate the friction loss of the gear; Calculating each set of initial tooth profile modification parameters by using an instantaneous transmission efficiency calculation equation to obtain the transmission efficiency of each set of the tooth profile modification parameters, wherein the instantaneous transmission efficiency calculation equation is used to calculate the transmission efficiency of the gear; According to the friction loss and transmission efficiency of each group of the tooth profile modification parameters, the fitness value of each group of the initial tooth profile modification parameters is obtained.

[0006] In some embodiments, the NW type compound planetary gear train includes a driving gear and a driven gear; The rolling friction force calculation equation is constructed based on the rolling friction coefficient and the load force, and the load force is determined based on the load distribution of the NW type compound planetary gear train; Wherein, the rolling friction coefficient is calculated according to the following steps: Calculating according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain a coefficient of recovery, wherein the coefficient of recovery is used to characterize the ability of the gear material to recover to its original shape after being deformed by force; The elastic hysteresis coefficient is calculated according to the load force, the comprehensive curvature radius, the recovery coefficient, the axial length of the cylinder and the pressure angle, wherein the comprehensive curvature radius is determined according to the curvature radius of the driving wheel and the curvature radius of the driven wheel, and the elastic hysteresis coefficient is used to characterize the delay phenomenon when the gear returns to its original state after being deformed by force; The rolling friction coefficient is obtained by calculation based on the restitution coefficient, the elastic hysteresis coefficient, the comprehensive curvature radius and the axial length of the cylinder.

[0007] In some embodiments, the geometric parameters of the driving wheel include the elastic modulus of the driving wheel and the Poisson's ratio of the driving wheel, and the geometric parameters of the driven wheel include the elastic modulus of the driven wheel and the Poisson's ratio of the driven wheel; The calculation is performed according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain the restitution coefficient, including: Taking the ratio of the elastic modulus of the driving wheel to the Poisson's ratio of the driving wheel as the first value; taking the ratio of the elastic modulus of the driven wheel to the Poisson's ratio of the driven wheel as the second value; The sum of the first value and the second value is taken as the third value; The restoration coefficient is obtained according to the product of the third value and the preset first coefficient.

[0008] In some embodiments, the elastic hysteresis coefficient is calculated according to the load force, the comprehensive curvature radius, the restitution coefficient, the axial length of the cylinder and the pressure angle, and includes: taking the ratio of the tangent function of the pressure angle to the restitution coefficient as a fourth value; The product of the comprehensive curvature radius and the axial length of the cylinder is taken as the fifth value; The ratio of the fifth value to the load force is used as a sixth value; The elastic hysteresis coefficient is obtained by calculating according to the fourth value and the sixth value.

[0009] In some embodiments, the instantaneous transfer efficiency calculation equation is obtained according to the following steps: According to the output power and input power of the NW type compound planetary gear train, an initial instantaneous transmission efficiency calculation equation is constructed; The initial instantaneous transmission efficiency calculation equation is adjusted according to the single-double teeth alternately meshing phenomenon and the rolling friction coefficient when the NW type compound planetary gear train is running, so as to obtain the instantaneous transmission efficiency calculation equation.

[0010] In some embodiments, the comprehensive radius of curvature is calculated according to the following steps: The product of the pressure angle and the pitch circle diameter of the driving wheel is used as the seventh value; Multiplying the second preset coefficient by the seventh value to obtain the curvature radius of the driving wheel; The ratio of the number of teeth of the driving wheel to the number of teeth of the driven wheel is used as the eighth value; taking the difference between the eighth value and the second preset coefficient as the ninth value; Multiplying the seventh value by the ninth value to obtain the curvature radius of the driven wheel; Adding the reciprocal of the curvature radius of the driving wheel and the reciprocal of the curvature radius of the driven wheel to obtain the comprehensive curvature radius; The inverse of the curvature radius of the driving wheel is added to the inverse of the curvature radius of the driven wheel to obtain the comprehensive curvature radius.

[0011] To achieve the above-mentioned purpose, a second aspect of the embodiment of the present application proposes a NW type compound planetary gear train transmission efficiency optimization device based on intelligent optimization, the device comprising: An acquisition module, used for acquiring a plurality of sets of initial tooth profile modification parameters, wherein the initial tooth profile modification parameters are used for modifying the gears in the NW type compound planetary gear train; A calculation module, used for performing calculations based on the multiple groups of initial tooth profile modification parameters to obtain a fitness value of each group of initial tooth profile modification parameters, wherein the fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters; An iteration module, used for iteratively calculating the multiple groups of initial tooth profile modification parameters through an intelligent optimization algorithm to obtain target tooth profile modification parameters, wherein the target tooth profile modification parameters are tooth profile modification parameters that meet preset conditions, wherein the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the preset conditions are used to indicate the transmission efficiency and friction loss of the gear; An adjustment module is used to adjust the tooth profile of the gear in the NW type compound planetary gear train by using the target tooth profile modification parameter.

[0012] To achieve the above-mentioned purpose, the third aspect of an embodiment of the present application proposes an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the NW-type compound planetary gear system transmission efficiency optimization method based on intelligent optimization as described in the first aspect above.

[0013] To achieve the above-mentioned purpose, the fourth aspect of an embodiment of the present application proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the NW-type compound planetary gear system transmission efficiency optimization method based on intelligent optimization described in the first aspect above.

[0014] The present application proposes a method, device, electronic device and storage medium for optimizing the transmission efficiency of a NW type compound planetary gear train based on intelligent optimization. By obtaining multiple groups of initial tooth profile modification parameters, the fitness value of each group of initial tooth profile modification parameters is calculated, and the transmission efficiency and friction loss of each group of initial tooth profile modification parameters are comprehensively considered through the fitness value. The multiple groups of initial tooth profile modification parameters are iteratively calculated through an intelligent optimization algorithm until preset conditions are met, and the iteration is stopped to obtain target tooth profile modification parameters. The optimal solution of the tooth profile modification parameters when taking into account transmission efficiency and friction loss is determined through an intelligent optimization algorithm, and the profile of the gears in the NW type compound planetary gear train is adjusted through the target tooth profile modification parameters to obtain a NW type compound planetary gear train with better transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of a method for optimizing the transmission efficiency of a NW type composite planetary gear train based on intelligent optimization provided in an embodiment of the present application; Figure 2 It is a schematic diagram of a model of an NW type compound planetary gear train provided in an embodiment of the present application; Figure 3 Schematic diagram of the phenomenon of alternating meshing of single and double teeth in the NW type compound planetary gear train provided in the embodiment of the present application; Figure 4 It is a structural schematic diagram of a NW type composite planetary gear train transmission efficiency optimization device based on intelligent optimization provided in an embodiment of the present application; Figure 5 It is a schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] It should be noted that, although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0019] The NW type compound planetary gear train has the phenomenon of alternating single and double teeth meshing, which causes a sudden change in the load distribution of the gears at different time points, easily leading to local stress concentration and increased impact load, thereby affecting the transmission smoothness and gear life. When the traditional power method calculates the gear transmission efficiency, it is usually assumed that the load distribution is uniform, and the problem of sudden load changes in actual operation is not fully considered. Therefore, when designing the tooth shape of the NW type compound planetary gear train, it is impossible to perform targeted optimization according to the meshing characteristics of the NW type compound planetary gear train, resulting in a low transmission efficiency of the NW type compound planetary gear train.

[0020] Based on this, the embodiments of the present application provide a method, device, electronic device and storage medium for optimizing the transmission efficiency of a NW-type compound planetary gear train based on intelligent optimization, aiming to solve the problem of low transmission efficiency of the existing NW-type compound planetary gear train.

[0021] The embodiments of the present application provide a method, device, electronic device and storage medium for optimizing the transmission efficiency of a NW-type compound planetary gear train based on intelligent optimization, which are specifically illustrated through the following embodiments. First, a method for optimizing the transmission efficiency of a NW-type compound planetary gear train based on intelligent optimization in the embodiments of the present application is described.

[0022] The embodiments of the present application can acquire and process relevant data based on artificial intelligence technology. Artificial Intelligence (AI) is the theory, method, technology and application system that uses digital computers or machines controlled by digital computers to simulate, extend and expand human intelligence, perceive the environment, acquire knowledge and use knowledge to obtain the best results.

[0023] AI basic technologies generally include sensors, dedicated AI chips, cloud computing, distributed storage, big data processing technology, operation / interaction systems, mechatronics, etc. AI software technologies mainly include computer vision technology, robotics technology, biometrics technology, speech processing technology, natural language processing technology, and machine learning / deep learning.

[0024] The embodiment of the present application provides a method for optimizing the transmission efficiency of a NW-type composite planetary gear train based on intelligent optimization, which relates to the field of machinery. The embodiment of the present application provides a method for optimizing the transmission efficiency of a NW-type composite planetary gear train based on intelligent optimization, which can be applied to a terminal, or to a server side, or it can be software running in a terminal or a server side. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, etc.; the server side can be configured as an independent physical server, or it can be configured as a server cluster or a distributed system composed of multiple physical servers, or it can be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms; the software can be an application that implements a method for optimizing the transmission efficiency of a NW-type composite planetary gear train based on intelligent optimization, etc., but is not limited to the above forms.

[0025] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0026] It should be noted that in each specific implementation of the present application, when it comes to the need to perform relevant processing based on data related to user identity or characteristics such as user information, user behavior data, user historical data, and user location information, the user's permission or consent will be obtained first, and the collection, use, and processing of these data will comply with relevant laws, regulations, and standards. In addition, when the embodiment of the present application needs to obtain the user's sensitive personal information, the user's separate permission or consent will be obtained through a pop-up window or by jumping to a confirmation page. After clearly obtaining the user's separate permission or consent, the necessary user-related data for the normal operation of the embodiment of the present application will be obtained.

[0027] Figure 1 This is a flow chart of a method for optimizing the transmission efficiency of a NW type composite planetary gear train based on intelligent optimization provided in an embodiment of the present application. Figure 1 A method for optimizing transmission efficiency of a NW-type composite planetary gear train based on intelligent optimization provided in an embodiment of the present application may include but is not limited to steps S101 to S104.

[0028] Step S101, obtaining a plurality of sets of initial tooth profile modification parameters, wherein the initial tooth profile modification parameters are used to modify the gears in the NW type compound planetary gear train.

[0029] In this step, each set of initial tooth profile modification parameters may be randomly generated or may be historical tooth profile modification parameters, which are not limited here. Each set of initial tooth profile modification parameters includes but is not limited to a maximum modification amount, a modification length, and a modification curve.

[0030] In this implementation, if Figure 2 As shown, the NW type compound planetary gear train includes an upper first-level planetary gear and a sun gear to form a gear pair, a lower first-level planetary gear and a sun gear to form a gear pair, the upper and lower first-level planetary gears are respectively connected to the secondary planetary gears, and the upper and lower secondary planetary gears and the fixed gear ring form a gear pair. (Definition of gear pair: the basic structure composed of two meshing gears) Step S102, performing calculations based on the multiple groups of initial tooth profile modification parameters to obtain a fitness value of each group of initial tooth profile modification parameters, wherein the fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters.

[0031] In this step, a corresponding gear tooth profile model is generated according to each set of initial tooth profile modification parameters, and the fitness value of the gear tooth profile model corresponding to each set of initial tooth profile modification parameters is calculated, and the fitness value of the gear tooth profile model is used as the fitness value of the corresponding initial tooth profile modification parameters.

[0032] Furthermore, a fitness value calculation function is established according to actual needs, and the fitness value of each gear tooth profile model is calculated by a preset fitness calculation function. The fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters.

[0033] In some implementations, after obtaining the fitness value corresponding to each set of initial tooth profile modification parameters, the initial tooth profile modification parameters are sorted according to the fitness value corresponding to each set of initial tooth profile modification parameters to improve the iteration efficiency of the intelligent optimization method.

[0034] Exemplarily, a fitness value calculation function is established according to the transmission efficiency and friction loss of the gear, and the fitness value calculation function can be expressed by the following formula 1: Fitness = a*A+b*B+U(1); In the formula, Fitness represents the fitness value, a represents the weight corresponding to the transmission efficiency, b represents the weight corresponding to the friction loss, A represents the transmission efficiency, B represents the friction loss, and U represents the penalty term.

[0035] Among them, the weight corresponding to the transmission efficiency, the weight corresponding to the friction loss and the penalty item can be set according to the actual situation. The penalty item is used to deal with the problem of parameter out-of-bounds, such as increasing the fitness value when the shaping amount exceeds the allowable range.

[0036] Step S103, iteratively calculating the multiple groups of initial tooth profile modification parameters through an intelligent optimization algorithm to obtain target tooth profile modification parameters, wherein the target tooth profile modification parameters are tooth profile modification parameters that meet preset conditions, and the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the preset conditions are used to indicate the transmission efficiency and friction loss of the gear.

[0037] In this step, the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the iterative optimization process of the multi-objective genetic algorithm is as follows: obtain multiple groups of initial tooth shape modification parameters as the initial population, and each group of initial tooth shape modification parameters as an individual; calculate the fitness value of each group of initial tooth shape modification parameters; sort the individuals in the population according to the Pareto dominance relationship, and determine the non-dominated solution sets of different levels, wherein the dominance relationship means that one solution is superior to another solution in all objectives, and the individuals in the population are divided into different front ends in the non-dominated solution set, and the first front end contains all non-dominated solutions; calculate the crowding degree of the individuals in each front end; use binary tournament selection to select parent individuals, and generate a new generation of solutions by simulating binary crossover and polynomial mutation; if the objective function converges to a stable Pareto solution set, output the target tooth shape modification parameters.

[0038] It should be noted that the objective function can be set according to actual conditions and is not limited here.

[0039] Step S104: using the target tooth profile modification parameters to adjust the tooth profile of the gear in the NW type compound planetary gear train.

[0040] In this step, the target tooth profile modification parameters include but are not limited to the rolling angle of the wheel in the modification section, the rolling angle at the starting point of the wheel modification, the rolling angle at the starting point of the wheel modification, the modification power index, the maximum modification amount and the modification length.

[0041] Furthermore, the shaping curve is determined by the rolling angle of the wheel in the shaping section, the rolling angle at the starting point of the wheel shaping, the rolling angle at the starting point of the wheel shaping, the shaping power index and the maximum shaping amount.

[0042] It should be noted that the small gear is the gear with the smaller number of teeth in the gear pair.

[0043] Specifically, the shaping curve can be expressed by the following formula 2: (2); In the formula, represents the shaping curve, Indicates the rolling angle of the small wheel in the shaping section, Indicates the maximum amount of shaping, represents the rolling angle at the starting point of the wheel modification, represents the rolling angle at the end point of the wheel shaping, Represents the shaping power exponent.

[0044] In the NW type compound planetary gear system, due to the alternating meshing of single and double teeth, in the single-tooth meshing area, the load is completely borne by one pair of teeth, while in the double-tooth meshing area, the load is shared by two pairs of teeth. Since the load in the single-tooth meshing area is significantly higher than that in the double-tooth meshing area, it is easy to cause excessive stress on the local tooth surface, aggravating fatigue damage, and the load distribution during the gear meshing process shows periodic changes.

[0045] In this implementation, the tooth profile of the gear in the NW type compound planetary gear train is adjusted and modified according to the modification curve, the maximum modification amount and the modification length, so as to optimize the contact state of the gear in the NW type compound planetary gear train, improve the uniformity of load distribution in the entire meshing process, reduce the local stress concentration effect, and thus improve the fatigue life and transmission efficiency of the NW type compound planetary gear train, wherein the tooth profile modification is to remove a part of the material that interferes from the tooth surface along the tooth height direction, thereby changing the shape of the tooth profile and the load distribution.

[0046] In this implementation, multiple groups of initial tooth profile modification parameters are obtained, the fitness value of each group of initial tooth profile modification parameters is calculated, the transmission efficiency and friction loss of each group of initial tooth profile modification parameters are comprehensively considered through the fitness value, the multiple groups of initial tooth profile modification parameters are iteratively calculated through an intelligent optimization algorithm until the preset conditions are met, and the iteration is stopped to obtain the target tooth profile modification parameters, the intelligent optimization algorithm is used to determine the optimal solution of the tooth profile modification parameters when taking into account the transmission efficiency and friction loss, and the profile of the gears in the NW type compound planetary gear train is adjusted according to the target tooth profile modification parameters to obtain an NW type compound planetary gear train with better transmission efficiency.

[0047] In some embodiments, the calculation in step S102 is performed based on the multiple groups of initial tooth profile modification parameters to obtain the fitness value of each group of initial tooth profile modification parameters, which may include but is not limited to steps S1021 to S1023.

[0048] Step S1021, calculating each group of the initial tooth profile modification parameters by using a rolling friction force calculation equation to obtain the friction loss of each group of the tooth profile modification parameters, wherein the rolling friction force calculation equation is used to calculate the friction loss of the gear.

[0049] Step S1022, calculating each set of initial tooth profile modification parameters by using an instantaneous transmission efficiency calculation equation to obtain the transmission efficiency of each set of the tooth profile modification parameters, wherein the instantaneous transmission efficiency calculation equation is used to calculate the transmission efficiency of the gear.

[0050] Step S1023: obtaining the fitness value of each group of the initial tooth profile modification parameters according to the friction loss and transmission efficiency of each group of the tooth profile modification parameters.

[0051] In this implementation, the rolling friction force calculation equation and the instantaneous efficiency calculation equation can be set according to actual conditions and are not limited here. For example, the rolling friction force calculation equation can use the elastic hydrodynamic lubrication (EHL) equation, and the instantaneous efficiency calculation equation can use the ratio of the output power to the input power of the NW type compound planetary gear train.

[0052] In the present implementation, a fitness value calculation function is pre-set. The setting method of the fitness value calculation function can be found in the record in step S102 and will not be elaborated here. According to each set of initial tooth profile modification parameters, a corresponding gear tooth profile model is generated, and the rolling friction loss of the gear tooth profile model corresponding to each set of initial tooth profile modification parameters is calculated by the rolling friction force calculation equation, and the rolling friction loss of the gear tooth profile model is used as the rolling friction loss of the corresponding initial tooth profile modification parameters. The transmission efficiency of the gear tooth profile model corresponding to each set of initial tooth profile modification parameters is calculated by the instantaneous transmission efficiency calculation equation, and the transmission efficiency of the gear tooth profile model is used as the transmission efficiency of the corresponding initial tooth profile modification parameters. The rolling friction loss and transmission efficiency corresponding to each set of initial tooth profile modification parameters are substituted into the preset fitness value calculation function to obtain the fitness value of each set of initial tooth profile modification parameters.

[0053] In this embodiment, the friction loss and transmission efficiency of the NW type compound planetary gear system are accurately calculated by the rolling friction force calculation equation and the instantaneous efficiency calculation equation, so as to accurately calculate the fitness value of each set of initial tooth profile modification parameters, so as to facilitate the subsequent iteration of tooth profile modification parameters that better meet actual needs.

[0054] In some embodiments, the rolling friction force calculation equation is constructed based on the rolling friction coefficient and the load force, and the load force is determined based on the load distribution of the NW type compound planetary gear train.

[0055] Furthermore, based on the influence of tooth surface error on the load distribution coefficient, a deformation coordination equation is established to determine the load distribution coefficient at the meshing position, and the load distribution is determined according to the load distribution coefficient to obtain the load force.

[0056] Furthermore, the deformation coordination equation can be expressed by the following equation 3: (3); In the formula, represents the gear transmission flexibility matrix, which is used to describe the local deformation effect of the contact point; Represents the overall deformation flexibility matrix of the gear, which is used to describe the elastic deformation effect of the gear at different meshing points; The flexibility matrix represents the effect of tooth profile modification on deformation; represents the deformation flexibility matrix after considering the error; Represents the identity matrix.

[0057] Furthermore, the load vector at the meshing point can be expressed by the following equation 4: (4); In the formula, Represents the load vector at the meshing point.

[0058] The gap vector can be expressed by the following equation 5: (5); In the formula, represents the gap vector.

[0059] Among them, Gap at meshing point It can be calculated by the following formula 6: (6); In the formula, Indicates The gap between the meshing points, Indicates the gear separation distance, used to describe the early engagement and delayed engagement of the loaded gear. Indicates the tooth surface error correction amount.

[0060] Furthermore, the initial contact force and iteration conditions are set. Specifically, in the solution process, in order to simplify the initial state and facilitate the subsequent iterative solution, it is assumed that the contact forces borne by all potential meshing points are equal at the beginning, that is, the load of each meshing point is evenly distributed. The initial contact force can be expressed by the following formula 7; according to the overall force balance, the sum of the meshing forces on all potential meshing points must be equal to the total load of the system: , thus obtaining the iteration condition, which can be expressed by the following formula 8: (7); (8); Combining the above equations 3 to 8, the final load distribution coefficient can be obtained, and the load distribution coefficient can be expressed by the following equation 9: (9); In the formula, It represents the load distribution coefficient, which indicates the proportion of the load at a certain meshing point to the total load. represents the total load, Indicates The meshing force at each meshing point.

[0061] By constructing the deformation coordination equation, setting the initial load, introducing the meshing clearance and error influence, and satisfying the total load balance constraint, the actual force of each meshing point can be solved, and then the load distribution coefficient can be determined. Among them, the rolling friction coefficient is calculated according to the following steps S201 to S203: Step S201, calculating according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain a coefficient of restitution, wherein the coefficient of restitution is used to characterize the ability of the gear material to recover to its original state after being deformed by force; Step S202, calculating according to the load force, the comprehensive radius of curvature, the coefficient of restitution, the axial length of the cylinder and the pressure angle to obtain an elastic hysteresis coefficient, wherein the comprehensive radius of curvature is determined according to the curvature radius of the driving wheel and the curvature radius of the driven wheel, and the elastic hysteresis coefficient is used to characterize the delay phenomenon when the gear returns to its original state after being deformed by force; Step S203, calculating according to the restitution coefficient, the elastic hysteresis coefficient, the comprehensive curvature radius and the axial length of the cylinder to obtain the rolling friction coefficient.

[0062] In this implementation, each gear pair in the NW type compound planetary gear train includes a driving wheel and a driven wheel. The rolling friction coefficient can be multiplied by the load force to obtain the rolling friction force. The rolling friction force calculation equation can be expressed by the following formula 10: (10); In the formula, is the rolling friction, is the rolling friction coefficient, Indicates the load force.

[0063] According to the change of gear load distribution coefficient, the load distribution in the gear contact area is determined to obtain the change of normal load when single and double teeth are alternating. Considering the material properties of the gear, the recovery coefficient k and elastic hysteresis loss coefficient ξ are calculated to obtain the dynamic rolling friction coefficient.

[0064] Specifically, the rolling friction coefficient can be calculated by the following formula 11: (11); In the formula, is the rolling friction coefficient, represents the tangential force, represents the normal force, represents the elastic hysteresis coefficient, represents the half width of the contact area, represents the integrated curvature radius, represents the load force, represents the elastic modulus, Represents the coefficient of restitution.

[0065] In this embodiment, the dynamic friction coefficient equation is constructed by combining the tooth surface lubrication characteristics and elastohydrodynamic lubrication theory, which can more accurately reflect the actual operating state of the gear, improve the accuracy of transmission efficiency calculation, and provide more reliable theoretical support for tooth profile optimization design.

[0066] In some implementations, the calculation in step S201 based on the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain the restitution coefficient may include but is not limited to steps S2011 to S2014.

[0067] Step S2011: taking the ratio of the elastic modulus of the driving wheel to the Poisson's ratio of the driving wheel as the first value.

[0068] Step S2012: taking the ratio of the elastic modulus of the driven wheel to the Poisson's ratio of the driven wheel as the second value.

[0069] Step S2013: taking the sum of the first value and the second value as the third value.

[0070] Step S2014: Obtain the restoration coefficient according to the product of the third value and the preset first coefficient.

[0071] Specifically, the recovery coefficient can be calculated by the following formula 12: (12); In the formula, represents the coefficient of restitution, represents the elastic modulus of the driving wheel, represents the elastic modulus of the driven wheel, represents the Poisson's ratio of the driving wheel, represents the Poisson's ratio of the driven wheel.

[0072] in, Recorded as the first value, Recorded as the second value, The third value is It is recorded as the first coefficient.

[0073] In some embodiments, the elastic hysteresis coefficient is calculated according to the load force, the comprehensive curvature radius, the restitution coefficient, the axial length of the cylinder and the pressure angle in step S202 to obtain the elastic hysteresis coefficient, which may include but is not limited to steps S2021 to S2024.

[0074] Step S2021: taking the ratio of the tangent value of the pressure angle to the coefficient of restitution as the fourth value.

[0075] Step S2022: taking the product of the comprehensive curvature radius and the axial length of the cylinder as the fifth value.

[0076] Step S2023: taking the ratio of the fifth value to the load force as the sixth value.

[0077] Step S2024: Calculate according to the fourth value and the sixth value to obtain the elastic hysteresis coefficient.

[0078] Specifically, the elastic hysteresis loss coefficient can be calculated by the following formula 13: (13); In the formula, represents the elastic hysteresis loss coefficient, represents the pressure angle, represents the integrated curvature radius, represents the axial length of the cylinder, Indicates the load force.

[0079] in, Recorded as the fourth value, Recorded as the fifth value, Recorded as the sixth value.

[0080] It should be noted that, under normal circumstances, two gears can only mesh with each other when the pressure angles are the same, so when calculating, it is not distinguished whether the pressure angle belongs to the driving wheel or the driven wheel.

[0081] In some embodiments, the instantaneous transfer efficiency calculation equation is obtained according to the following steps S301 to S302: Step S301, constructing an initial instantaneous transfer efficiency calculation equation according to the output power and input power of the NW type compound planetary gear train; Step S302: adjusting the initial instantaneous transmission efficiency calculation equation according to the single- and double-tooth alternating meshing phenomenon and the rolling friction coefficient when the NW type compound planetary gear train is running, to obtain an instantaneous transmission efficiency calculation equation.

[0082] like Figure 3 As shown in the figure, in the NW type compound planetary gear system, in order to ensure the continuity of the fixed transmission ratio transmission of the gears, the meshing line length must be greater than or equal to the base circle pitch to ensure that when the first pair of teeth separates, the second pair of teeth has entered into meshing. In the transmission process, the low overlap gears will have single-tooth meshing areas and double-tooth meshing areas, that is, the single and double teeth are alternately meshed.

[0083] The gear is in front of the node P and after node P Meshing at the meshing point For analysis, assume that the tangential speeds of the driving wheel and the driven wheel at this point are and , It can be expressed by the following formula 14: It can be expressed by the following formula 15: (14); (15); In the formula, represents the tangential speed of the driving wheel at the meshing point, represents the tangential speed of the driven gear at the meshing point, represents the base circle radius of the driving wheel, represents the base circle radius of the driven wheel, represents the pressure angle of the driving wheel, represents the pressure angle of the driven wheel, represents the driving wheel angle, Indicates meshing point With meshing point The distance Indicates meshing point With meshing point The distance Indicates the driven wheel rotation angle.

[0084] According to the definition of instantaneous efficiency, that is, the ratio of output power to input power, the initial instantaneous transfer efficiency calculation equation is constructed. The initial instantaneous transfer efficiency calculation equation can be expressed by the following equation 16: (16); In the formula, represents the instantaneous transfer efficiency, represents the input torque, represents the output torque, represents the driving wheel angle, represents the driven wheel rotation angle, represents the base circle radius of the driving wheel, Indicates the base circle radius of the driven wheel.

[0085] In order to ensure the continuity of the fixed transmission ratio of the gears, the continuous transmission condition must be met when the gears are meshing. The meshing line length is greater than or equal to the base circle pitch, that is, the gear overlap is ≥1. When the gears are actually meshing, the alternating meshing phenomenon of single and double teeth and rolling friction must also be considered. In order to facilitate subsequent analysis, the two sets of gear pairs in the NW type compound planetary gear train, one set of gear pairs is defined as the main meshing tooth pair, and the other set is the secondary meshing tooth pair. It is not limited here to which specific gear pair the main meshing tooth pair and the secondary meshing tooth pair are.

[0086] Specifically, when the main meshing tooth pair is at the meshing point , the secondary meshing tooth pair is at the meshing point When , the corresponding torque equation can be expressed by the following equations 17 and 18: (17); (18); In the formula, represents the base circle radius of the driving wheel, represents the base circle radius of the driven wheel, represents the normal load at the first meshing point, represents the normal load at the second meshing point, Indicates the meshing point K and meshing point The distance between represents the base circle pitch, represents the sliding friction coefficient of the driving wheel, represents the sliding friction coefficient of the driven wheel, Indicates meshing point and meshing point The distance between represents the radial force component at the first meshing point, Represents the radial component of the second meshing point.

[0087] It should be noted that the sliding friction coefficient can be set according to actual conditions and is not limited here; in general, the sliding friction coefficient takes a value between 0.03 and 0.07.

[0088] Among them, the base circle pitch It can be calculated by the following formula 19: (19); In the formula, represents the base circle pitch, represents the modulus, Represents the pressure angle.

[0089] Combining the above equations 16, 17, and 18, the instantaneous transfer efficiency here can be expressed by the following equation 20: (20); In the formula, represents the rotation angle of the driving wheel, represents the rotation angle of the driven wheel, and N represents the normal load ratio of the driving wheel and the driven wheel, that is, N= .

[0090] Among them, the rotation angle of the driven wheel It can be calculated by the following formula 21: (twenty one); When the main meshing teeth are at the meshing point , the secondary meshing tooth pair is at the meshing point When , the corresponding torque equation can be expressed by the following equations 22 and 23: (twenty two); (twenty three); Combining the above equations 16, 22, and 23, the instantaneous transfer efficiency here can be expressed by the following equation 24: (twenty four); Combining the above equations 20 and 24, and based on the rolling friction and the phenomenon of alternating meshing of single and double teeth, the calculation equation for the instantaneous transmission efficiency of the NW compound planetary gear train can be derived. The calculation equation for the instantaneous transmission efficiency of the NW compound planetary gear train can be expressed by the following equation 25: (25); In the formula, represents the rolling friction coefficient of the driving wheel, represents the rolling friction coefficient of the driven wheel, It represents the distance from the meshing point to the node. represents the distance from the engagement point to the node, Represents the pressure angle.

[0091] It should be noted that the node is the intersection of the common normal line of the tooth profile contact point and the center line.

[0092] Among them, the meshing point to the node It can be calculated by the following formula 26: (26); Distance from the engagement point to the node It can be calculated by the following formula 27: (27); In this embodiment, based on the single-double tooth meshing phenomenon and the rolling friction coefficient of the NW compound planetary gear train, an instantaneous transmission efficiency calculation equation is constructed to improve the accuracy of calculating the instantaneous transmission efficiency.

[0093] In some other implementations, the above equation 25 may be used as the objective function in step S103.

[0094] In some embodiments, the comprehensive curvature radius is calculated according to the following steps S401 to S406: Step S401, taking the product of the pressure angle and the pitch circle diameter of the driving wheel as the seventh value; Step S402, multiplying the second preset coefficient by the seventh value to obtain the curvature radius of the driving wheel; Step S403, taking the ratio of the number of teeth of the driving wheel to the number of teeth of the driven wheel as the eighth value; Step S404: taking the difference between the eighth value and the second preset coefficient as the ninth value; Step S405, multiplying the seventh value by the ninth value to obtain the curvature radius of the driven wheel; Step S406: Add the inverse of the radius of curvature of the driving wheel and the inverse of the radius of curvature of the driven wheel to obtain the comprehensive radius of curvature.

[0095] Specifically, the curvature radius of the driving wheel at the meshing point can be calculated by the following formula 28: (28); In the formula, It represents the radius of curvature of the driving wheel at the meshing point. represents the dimensionless parameter on the meshing line, Indicates the pitch circle diameter of the driving wheel, Represents the pressure angle.

[0096] The radius of curvature of the driven gear at the meshing point can be calculated by the following formula 29: (29); In the formula, Indicates the transmission ratio, It is equal to the ratio of the number of teeth on the driving wheel to the number of teeth on the driven wheel.

[0097] Furthermore, when the meshing line is at the tangent point with the base circle of the driving wheel, the dimensionless parameter is equal to 1.

[0098] Furthermore, at the lower boundary point of the contact trajectory, the lower boundary point of the contact trajectory is the lowest point in the tooth surface contact trajectory, that is, the position where the tooth surface begins to contact during the meshing process. The dimensionless parameter It can be calculated by the following formula 30: (30); In the formula, Indicates the number of teeth on the driving wheel. Indicates the number of teeth on the driven wheel, It represents the pressure angle of the driven gear tooth top circle, Represents the pressure angle.

[0099] in, It can be calculated by the following formula 31: (31); Furthermore, at the upper boundary point of the contact trajectory, the upper boundary point of the contact trajectory is the highest point in the tooth surface contact trajectory, that is, the position where the tooth surface contact ends during the meshing process. The dimensionless parameter It can be calculated by the following formula 32: (32); In the formula, It represents the pressure angle of the top circle of the driving gear tooth. Represents the pressure angle.

[0100] in, It can be calculated by the following formula 33: (33); In the formula, represents the diameter of the tooth tip circle, Indicates the pitch circle diameter of the driving wheel, Represents the pressure angle.

[0101] It should be noted that Recorded as the seventh value, Recorded as the eighth value, Recorded as the ninth value, It is recorded as the second preset coefficient.

[0102] In this embodiment, since the comprehensive curvature radius determines the characteristics of the tooth surface rolling friction, the larger the curvature radius, the more uniform the contact pressure distribution. The calculation accuracy of the rolling friction force and the instantaneous efficiency is improved by accurately calculating the comprehensive curvature radius.

[0103] Figure 4 This is a schematic diagram of the structure of the NW type composite planetary gear train transmission efficiency optimization device based on intelligent optimization provided in the embodiment of the present application. Figure 4 The embodiment of the present application further provides a NW type compound planetary gear train transmission efficiency optimization device 800 based on intelligent optimization, which can realize the above-mentioned NW type compound planetary gear train transmission efficiency optimization method based on intelligent optimization. The NW type compound planetary gear train transmission efficiency optimization device 800 based on intelligent optimization includes: An acquisition module 801 is used to acquire multiple sets of initial tooth profile modification parameters, where the initial tooth profile modification parameters are used to modify the gears in the NW type compound planetary gear train; A calculation module 802, configured to perform calculations based on the multiple groups of initial tooth profile modification parameters to obtain a fitness value of each group of initial tooth profile modification parameters, wherein the fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters; An iteration module 803 is used to iteratively calculate the multiple groups of initial tooth profile modification parameters through an intelligent optimization algorithm to obtain target tooth profile modification parameters, wherein the target tooth profile modification parameters are tooth profile modification parameters that meet preset conditions, wherein the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the preset conditions are used to indicate the transmission efficiency and friction loss of the gear; The adjustment module 804 is used to adjust the tooth profile of the gear in the NW type compound planetary gear train by using the target tooth profile modification parameter.

[0104] In some implementations, the computing module 802 includes: A first calculation submodule is used to calculate each group of the initial tooth profile modification parameters by a rolling friction force calculation equation to obtain the friction loss of each group of the tooth profile modification parameters, wherein the rolling friction force calculation equation is used to calculate the friction loss of the gear; A second calculation submodule is used to calculate each set of initial tooth profile modification parameters by using an instantaneous transmission efficiency calculation equation to obtain the transmission efficiency of each set of the tooth profile modification parameters, wherein the instantaneous transmission efficiency calculation equation is used to calculate the transmission efficiency of the gear; The third calculation submodule is used to obtain the fitness value of each group of the initial tooth profile modification parameters according to the friction loss and transmission efficiency of each group of the tooth profile modification parameters.

[0105] In some embodiments, the NW type compound planetary gear train includes a driving gear and a driven gear; The rolling friction force calculation equation is constructed based on the rolling friction coefficient and the load force, and the load force is determined based on the load distribution of the NW type compound planetary gear train; Wherein, the rolling friction coefficient is calculated according to the following steps: Calculating according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain a coefficient of recovery, wherein the coefficient of recovery is used to characterize the ability of the gear material to recover to its original shape after being deformed by force; The elastic hysteresis coefficient is calculated according to the load force, the comprehensive curvature radius, the recovery coefficient, the axial length of the cylinder and the pressure angle, wherein the comprehensive curvature radius is determined according to the curvature radius of the driving wheel and the curvature radius of the driven wheel, and the elastic hysteresis coefficient is used to characterize the delay phenomenon when the gear returns to its original state after being deformed by force; The rolling friction coefficient is obtained by calculation based on the restitution coefficient, the elastic hysteresis coefficient, the comprehensive curvature radius and the axial length of the cylinder.

[0106] In some embodiments, the geometric parameters of the driving wheel include the elastic modulus of the driving wheel and the Poisson's ratio of the driving wheel, and the geometric parameters of the driven wheel include the elastic modulus of the driven wheel and the Poisson's ratio of the driven wheel; The calculation is performed according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain the restitution coefficient, including: Taking the ratio of the elastic modulus of the driving wheel to the Poisson's ratio of the driving wheel as the first value; taking the ratio of the elastic modulus of the driven wheel to the Poisson's ratio of the driven wheel as the second value; The sum of the first value and the second value is taken as the third value; The restoration coefficient is obtained according to the product of the third value and the preset first coefficient.

[0107] In some embodiments, the elastic hysteresis coefficient is calculated according to the load force, the comprehensive curvature radius, the restitution coefficient, the axial length of the cylinder and the pressure angle, and includes: taking the ratio of the tangent value of the pressure angle to the restitution coefficient as the fourth value; The product of the comprehensive curvature radius and the axial length of the cylinder is taken as the fifth value; The ratio of the fifth value to the load force is used as a sixth value; The elastic hysteresis coefficient is obtained by calculating according to the fourth value and the sixth value.

[0108] In some embodiments, the instantaneous transfer efficiency calculation equation is obtained according to the following steps: According to the output power and input power of the NW type compound planetary gear train, an initial instantaneous transmission efficiency calculation equation is constructed; The initial instantaneous transmission efficiency calculation equation is adjusted according to the phenomenon of alternating meshing of single and double teeth during operation of the NW type compound planetary gear train and the rolling friction coefficient to obtain the instantaneous transmission efficiency calculation equation.

[0109] In some embodiments, the comprehensive radius of curvature is calculated according to the following steps: The product of the rolling angle of the driving wheel and the pitch circle diameter of the driving wheel is taken as the seventh value; Multiplying the first value by the second preset coefficient to obtain the curvature radius of the driving wheel; The product of the rolling angle of the driven wheel and the pitch circle diameter of the driven wheel is taken as the eighth value; The ratio of the number of teeth of the driving wheel to the number of teeth of the driven wheel is used as the ninth value; taking the difference between the ninth value and the second preset coefficient as the tenth value; multiplying the eighth value by the tenth value to obtain the curvature radius of the driven wheel; The inverse of the curvature radius of the driving wheel is added to the inverse of the curvature radius of the driven wheel to obtain the comprehensive curvature radius.

[0110] The specific implementation of the NW type compound planetary gear train transmission efficiency optimization device 800 based on intelligent optimization is basically the same as the specific implementation of the above-mentioned NW type compound planetary gear train transmission efficiency optimization method based on intelligent optimization, and will not be repeated here.

[0111] The embodiment of the present application also provides an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the above-mentioned NW type composite planetary gear transmission efficiency optimization method based on intelligent optimization when executing the computer program. The electronic device can be any intelligent terminal including a desktop computer, a tablet computer, a mobile phone, and a car computer.

[0112] See also Figure 5 , Figure 5 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application, wherein the electronic device includes: The processor 901 may be implemented by a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application; The memory 902 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 902 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 902, and the processor 901 calls and executes the NW type compound planetary gear transmission efficiency optimization method based on intelligent optimization in the embodiment of this application; Input / output interface 903, used to implement information input and output; Communication interface 904, used to realize communication interaction between the device and other devices, which can be realized through wired mode (such as USB, network cable, etc.) or wireless mode (such as mobile network, WIFI, Bluetooth, etc.); A bus 905 that transmits information between various components of the device (e.g., the processor 901, the memory 902, the input / output interface 903, and the communication interface 904); The processor 901 , the memory 902 , the input / output interface 903 and the communication interface 904 are connected to each other in communication within the device via a bus 905 .

[0113] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned NW type compound planetary gear train transmission efficiency optimization method based on intelligent optimization.

[0114] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0115] The transmission efficiency optimization method of a NW type compound planetary gear train based on intelligent optimization provided in an embodiment of the present application obtains multiple groups of initial tooth profile modification parameters, calculates the fitness value of each group of initial tooth profile modification parameters, comprehensively considers the transmission efficiency and friction loss of each group of initial tooth profile modification parameters through the fitness value, iteratively calculates the multiple groups of initial tooth profile modification parameters through an intelligent optimization algorithm until preset conditions are met, and stops iteration to obtain target tooth profile modification parameters, determines the optimal solution of the tooth profile modification parameters when taking into account transmission efficiency and friction loss through an intelligent optimization algorithm, and adjusts the profile of the gears in the NW type compound planetary gear train through the target tooth profile modification parameters to obtain a NW type compound planetary gear train with better transmission efficiency.

[0116] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0117] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0118] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0119] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0120] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0121] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0122] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as 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 mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0123] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they 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.

[0124] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0125] If the integrated unit is implemented in the form of a software functional unit 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, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including multiple instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store programs.

[0126] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A method for optimizing transmission efficiency of a NW type composite planetary gear train based on intelligent optimization, characterized in that: The method comprises: Acquire multiple sets of initial tooth profile modification parameters, where the initial tooth profile modification parameters are used to modify the gears in the NW type compound planetary gear train; Calculating according to the multiple groups of initial tooth profile modification parameters to obtain a fitness value of each group of initial tooth profile modification parameters, wherein the fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters; Iteratively calculating multiple groups of the initial tooth profile modification parameters through an intelligent optimization algorithm to obtain target tooth profile modification parameters, wherein the target tooth profile modification parameters are tooth profile modification parameters that meet preset conditions, wherein the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the preset conditions are used to indicate the transmission efficiency and friction loss of the gear; The target tooth profile modification parameters are used to adjust the tooth profile of the gear in the NW type compound planetary gear train.

2. The method according to claim 1, characterized in that The step of calculating according to the multiple groups of initial tooth profile modification parameters to obtain the fitness value of each group of initial tooth profile modification parameters includes: Calculate each group of the initial tooth profile modification parameters by using a rolling friction force calculation equation to obtain the friction loss of each group of the tooth profile modification parameters, wherein the rolling friction force calculation equation is used to calculate the friction loss of the gear; Calculating each set of initial tooth profile modification parameters by using an instantaneous transmission efficiency calculation equation to obtain the transmission efficiency of each set of the tooth profile modification parameters, wherein the instantaneous transmission efficiency calculation equation is used to calculate the transmission efficiency of the gear; According to the friction loss and transmission efficiency of each group of the tooth profile modification parameters, the fitness value of each group of the initial tooth profile modification parameters is obtained.

3. The method according to claim 2, characterized in that The NW type compound planetary gear train includes a driving wheel and a driven wheel; The rolling friction force calculation equation is constructed based on the rolling friction coefficient and the load force, and the load force is determined based on the load distribution of the NW type compound planetary gear train; Wherein, the rolling friction coefficient is calculated according to the following steps: Calculating according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain a coefficient of recovery, wherein the coefficient of recovery is used to characterize the ability of the gear material to recover to its original shape after being deformed by force; The elastic hysteresis coefficient is calculated according to the load force, the comprehensive curvature radius, the recovery coefficient, the axial length of the cylinder and the pressure angle, wherein the comprehensive curvature radius is determined according to the curvature radius of the driving wheel and the curvature radius of the driven wheel, and the elastic hysteresis coefficient is used to characterize the delay phenomenon when the gear returns to its original state after being deformed by force; The rolling friction coefficient is obtained by calculation based on the restitution coefficient, the elastic hysteresis coefficient, the comprehensive curvature radius and the axial length of the cylinder.

4. The method according to claim 3, characterized in that The geometric parameters of the driving wheel include the elastic modulus of the driving wheel and the Poisson's ratio of the driving wheel, and the geometric parameters of the driven wheel include the elastic modulus of the driven wheel and the Poisson's ratio of the driven wheel; The calculation is performed according to the geometric parameters of the driving wheel and the geometric parameters of the driven wheel to obtain the restitution coefficient, including: Taking the ratio of the elastic modulus of the driving wheel to the Poisson's ratio of the driving wheel as the first value; taking the ratio of the elastic modulus of the driven wheel to the Poisson's ratio of the driven wheel as the second value; The sum of the first value and the second value is taken as the third value; The restoration coefficient is obtained according to the product of the third value and the preset first coefficient.

5. The method according to claim 3, characterized in that: The elastic hysteresis coefficient is obtained by calculating according to the load force, the comprehensive curvature radius, the restitution coefficient, the axial length of the cylinder and the pressure angle, including: taking the ratio of the tangent function of the pressure angle to the restitution coefficient as a fourth value; The product of the comprehensive curvature radius and the axial length of the cylinder is taken as the fifth value; The ratio of the fifth value to the load force is used as a sixth value; The elastic hysteresis coefficient is obtained by calculating according to the fourth value and the sixth value.

6. The method according to claim 3, characterized in that The instantaneous transfer efficiency calculation equation is obtained according to the following steps: According to the output power and input power of the NW type compound planetary gear train, an initial instantaneous transmission efficiency calculation equation is constructed; The initial instantaneous transmission efficiency calculation equation is adjusted according to the single-double teeth alternately meshing phenomenon and the rolling friction coefficient when the NW type compound planetary gear train is running, so as to obtain the instantaneous transmission efficiency calculation equation.

7. The method according to claim 3, characterized in that The comprehensive curvature radius is calculated according to the following steps: The product of the pressure angle and the pitch circle diameter of the driving wheel is used as the seventh value; Multiplying the second preset coefficient by the seventh value to obtain the curvature radius of the driving wheel; The ratio of the number of teeth of the driving wheel to the number of teeth of the driven wheel is used as the eighth value; taking the difference between the eighth value and the second preset coefficient as the ninth value; Multiplying the seventh value by the ninth value to obtain the curvature radius of the driven wheel; The inverse of the curvature radius of the driving wheel is added to the inverse of the curvature radius of the driven wheel to obtain the comprehensive curvature radius.

8. A NW type composite planetary gear train transmission efficiency optimization device based on intelligent optimization, characterized in that: The device comprises: An acquisition module, used for acquiring a plurality of sets of initial tooth profile modification parameters, wherein the initial tooth profile modification parameters are used for modifying the gears in the NW type compound planetary gear train; A calculation module, used for performing calculations based on the multiple groups of initial tooth profile modification parameters to obtain a fitness value of each group of initial tooth profile modification parameters, wherein the fitness value is used to characterize the quality of the corresponding initial tooth profile modification parameters; An iteration module, used for iteratively calculating the multiple groups of initial tooth profile modification parameters through an intelligent optimization algorithm to obtain target tooth profile modification parameters, wherein the target tooth profile modification parameters are tooth profile modification parameters that meet preset conditions, wherein the intelligent optimization algorithm includes a multi-objective genetic algorithm, and the preset conditions are used to indicate the transmission efficiency and friction loss of the gear; An adjustment module is used to adjust the tooth profile of the gear in the NW type compound planetary gear train by using the target tooth profile modification parameter.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the NW type compound planetary gear transmission efficiency optimization method based on intelligent optimization as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for optimizing the transmission efficiency of a NW-type compound planetary gear train based on intelligent optimization according to any one of claims 1 to 7 is implemented.

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