A method, system and application for evaluating the motion accuracy retention of a mechanical transmission system

Abstract

The present invention belongs to the technical field of motion accuracy design and analysis of mechanical transmission systems, and provides a method, system, and application for evaluating the motion accuracy retention of mechanical transmission systems. The method includes structurally decomposing the mechanical transmission system based on meta-action theory to obtain multiple meta-action units; constructing a motion error calculation model based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the meta-action units, and using the model to determine the initial motion error, maximum allowable motion error, and time-varying motion error of the mechanical transmission system; constructing a motion accuracy margin calculation model for the mechanical transmission system based on the initial motion error and maximum allowable motion error; and constructing a motion accuracy retention calculation model for the mechanical transmission system using the motion accuracy margin calculation model, the initial motion error, and the time-varying motion error, and using the model to evaluate the motion accuracy retention of the mechanical transmission system. The present invention can quantitatively evaluate the motion accuracy retention of a mechanical transmission system.

Description

Technical Field

[0001] The present application relates to the technical field of motion accuracy design and analysis of mechanical transmission systems, and in particular to a method, system, and application for evaluating the retention of motion accuracy of mechanical transmission systems. Background Art

[0002] Kinematic accuracy retention is a key performance indicator of mechanical transmission systems, describing their ability to maintain designed motion accuracy. Mechanical transmission systems are also crucial components of high-end CNC equipment, such as high-precision machine tools. Their kinematic accuracy retention determines the overall system's accuracy lifespan. However, mechanical transmission systems suffer from numerous sources of kinematic error, unclear error transmission mechanisms, and complex transmission processes, making accuracy retention assessment difficult.

[0003] At present, there are few studies on the evaluation of motion accuracy retention of mechanical transmission systems at home and abroad. In 2022, Zhang Shengyong et al. from Chongqing University published an article entitled "Quantitative Evaluation of Accuracy Retention and Analysis of Accuracy Degradation Mechanism" in the 58th volume of the 7th issue of the Journal of Mechanical Engineering. They analyzed the accuracy degradation mechanism of the meta-action unit and proposed a quantitative evaluation method for meta-action accuracy retention that combines the accuracy degradation rate and accuracy life. In 2023, Ran Yan et al. from Chongqing University published an article entitled "Motion Error Transmission and Comprehensive Precision Modeling of Meta-Action Chain of CNC Machine Tools" in the 59th volume of the 23rd issue of the Journal of Mechanical Engineering. They analyzed the motion error transmission process of the mechanical transmission system and established a motion accuracy model. In 2023, Wang Yongqing et al. from Dalian University of Technology disclosed a static and dynamic comprehensive evaluation method for the accuracy retention of CNC machine tools in patent CN117521513A, which comprehensively evaluated the accuracy retention capability of CNC machine tools from the dimensions of service conditions, accuracy degradation process and accuracy degradation results.

[0004] Based on the meta-motion theory and analysis methods, it is known that the structural decomposition of high-end CNC equipment such as CNC machine tools can be divided into three levels: the entire machine system - the meta-motion chain (mechanical transmission system) - the meta-motion. Based on this, Zhang Shengyong of Chongqing University pointed out in his paper "Research on the Precision Retention Technology of Mechanical Meta-motion Units": Based on the meta-motion theory of mechanical transmission systems, the elements that form the meta-motion accuracy during the processing, assembly, and service of the meta-motion unit are identified and extracted, and then an analysis method for the formation and degradation mechanism of meta-motion accuracy is proposed. Finally, through in-depth research on the laws of meta-motion accuracy degradation, a quantitative evaluation index for accuracy retention is established. The paper establishes a mathematical model for the motion error of mechanical meta-motions that takes into account the geometric errors of the meta-motion unit components, the assembly errors of the meta-motion unit, and the input errors of the meta-motion. The motion errors of the mechanical transmission system are mainly composed of three parts: input error, assembly error, and geometric error of the output component. The paper also points out the degradation mechanisms of meta-motion accuracy under the influence of five typical types of accuracy degradation causes: impurities, corrosion, wear, deformation, and aging.

[0005] However, the meta-action unit is the underlying foundation of the mechanical transmission system, and quantitative evaluation methods for its precision retention cannot accurately assess the motion errors of the upper-level logical meta-action chain. An analysis of existing precision retention evaluation techniques reveals that these methods primarily focus on the meta-action unit and CNC machine tool levels, lacking a motion precision retention evaluation method for the mechanical transmission system level (meta-action chain). Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method, system and application for evaluating the motion accuracy retention of a mechanical transmission system, which can perform quantitative evaluation on the motion accuracy retention of a mechanical transmission system.

[0007] To achieve the above-mentioned and related purposes, the present invention adopts the following technical solutions:

[0008] A first aspect of the present invention provides a method for evaluating the kinematic accuracy retention of a mechanical transmission system, comprising the following steps:

[0009] S1. Based on the meta-action theory, the mechanical transmission system is decomposed to obtain multiple meta-action units;

[0010] S2. Construct a motion error calculation model for the mechanical transmission system based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion units;

[0011] S3. Determine the initial motion error, maximum allowable motion error, and time-varying motion error of the mechanical transmission system using the motion error calculation model;

[0012] S4. Construct a motion accuracy margin calculation model for the mechanical transmission system based on the initial motion error and the maximum allowable motion error;

[0013] S5. Use the motion accuracy margin calculation model, initial motion error, and time-varying motion error to construct a motion accuracy retention calculation model for the mechanical transmission system, and evaluate the motion accuracy retention of the mechanical transmission system based on the motion accuracy retention calculation model.

[0014] According to the above technical means, the present invention is based on the meta-motion theory and starts from the formation and transmission process of the motion error of the mechanical transmission system to establish a motion error calculation model. Based on this basic model, combined with the initial motion error, maximum allowable error and time-varying motion error, the motion retention model of the mechanical transmission system is analyzed and established, and the motion accuracy retention is quantitatively evaluated.

[0015] Furthermore, the precision degradation data of the meta-action unit in step S2 includes looseness data, wear data, deformation data and aging data of parts in two adjacent meta-action units.

[0016] Furthermore, the initial motion error in step S3 is positively correlated with the machining error of the parts in the meta-action unit and the assembly error of the meta-action unit.

[0017] Furthermore, constructing a motion error calculation model of the mechanical transmission system in step S2 includes:

[0018] Based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion units, the time-varying characteristic quantities and their degradation rates, as well as the characteristic quantities that do not vary with time, of two adjacent elementary motion units are analyzed to determine the motion error of the kinematic pair consisting of the power output and power input components of the two adjacent elementary motion units.

[0019] The transmission ratio of the kinematic pair consisting of the power output and power input parts of two adjacent elementary action units is obtained, and a kinematic error calculation model of the mechanical transmission system is constructed based on the kinematic error and transmission ratio of the kinematic pair.

[0020] Furthermore, the construction of the motion accuracy margin calculation model of the mechanical transmission system in step S4 includes:

[0021] A motion accuracy margin of the mechanical transmission system is determined, wherein the motion accuracy margin is the difference between the maximum motion error and the initial motion error.

[0022] Furthermore, in step S5, the motion accuracy maintenance calculation model of the mechanical transmission system is constructed, including:

[0023] Determining a degradation amount of motion accuracy of the mechanical transmission system, wherein the degradation amount is the difference between the motion error at any moment and the initial motion error;

[0024] Determining a motion accuracy margin residual value of the mechanical transmission system based on the motion accuracy margin and the degradation amount, wherein the motion accuracy margin residual value is a difference between the motion accuracy margin and the degradation amount;

[0025] Based on the motion accuracy margin remaining value and the motion accuracy margin, a motion accuracy retention degree of the mechanical transmission system is determined, wherein the motion accuracy retention degree is a ratio of the motion accuracy margin remaining value to the motion accuracy margin.

[0026] A second aspect of the present invention provides a system for evaluating the motion accuracy retention of a mechanical transmission system, comprising:

[0027] Decomposition module, used to decompose the structure of the mechanical transmission system based on the meta-action theory to obtain multiple meta-action units;

[0028] The first modeling module is used to construct a motion error calculation model of the mechanical transmission system based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion unit;

[0029] an error determination module, for determining an initial motion error, a maximum allowable motion error, and a time-varying motion error of a mechanical transmission system using a motion error calculation model;

[0030] The second modeling module is used to construct a motion accuracy margin calculation model of the mechanical transmission system based on the initial motion error and the maximum allowable motion error;

[0031] The evaluation module is used to construct a motion accuracy retention calculation model of the mechanical transmission system by using the motion accuracy margin calculation model, the initial motion error and the time-varying motion error, and to evaluate the motion accuracy retention of the mechanical transmission system based on the motion accuracy retention calculation model.

[0032] Furthermore, it also includes an acquisition module for acquiring precision degradation data of the meta-action unit, and the precision degradation data includes looseness data, wear data, deformation data and aging data of parts in two adjacent meta-action units.

[0033] A third aspect of the present invention provides a computer-readable storage medium having computer-readable instructions stored thereon. When the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the above-mentioned method for evaluating the motion accuracy retention of a mechanical transmission system.

[0034] The fourth aspect of the present invention provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that when the processor executes the computer program, the steps of the above-mentioned method for evaluating the motion accuracy retention of a mechanical transmission system are implemented.

[0035] The beneficial technical effects of the present invention are:

[0036] The present invention uses the meta-action theory to decompose the structure of the mechanical transmission system to obtain the meta-action unit. Taking the meta-action as the minimum analysis unit and based on the precision degradation data of the meta-action unit, the formation mechanism of the motion error of the kinematic pairs of two adjacent meta-action units is analyzed, and a motion error calculation model of the mechanical transmission system is established based on this.

[0037] The present invention then uses a kinematic error calculation model to determine the initial kinematic error, maximum allowable kinematic error, and time-varying kinematic error of the mechanical transmission system. Based on this error data, a kinematic accuracy retention calculation model is constructed for the mechanical transmission system, and the accuracy of the mechanical transmission system is evaluated based on the kinematic accuracy retention calculation model. The present method is suitable for calculating kinematic accuracy retention of mechanical transmission systems during the design phase, as well as for analyzing and evaluating the accuracy of mechanical transmission systems.

[0038] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and it is possible for a person of ordinary skill in the art to derive other drawings based on these drawings without inventive effort. In the accompanying drawings:

[0040] Figure 1 This is a flow chart of a method for evaluating the motion accuracy retention of a mechanical transmission system according to an embodiment of the present application;

[0041] Figure 2 This is a flowchart of an analysis method for evaluating the motion accuracy retention of a mechanical transmission system according to one embodiment of the present application;

[0042] Figure 3 This is a framework diagram of a system for evaluating the motion accuracy retention of a mechanical transmission system according to one embodiment of the present application;

[0043] Figure 4 This is a structural diagram of a CNC turntable system according to an embodiment of the present application;

[0044] Figure 5 This is an exploded view of the structure of a CNC turntable system according to one embodiment of the present application;

[0045] Figure 6 This is a power transmission diagram of a CNC turntable system according to an embodiment of the present application;

[0046] Figure 7 A schematic structural diagram of a computer system suitable for a computer device according to an embodiment of the present application is shown.

[0047] Reference numerals

[0048] 1: Base; 2: Turbine; 3: Spindle; 4: Workbench; 5: Bearing; 6: Piston; 7: Brake plate; 8: Worm; 9: Intermediate gear; 10: Support plate; 11: Motor gear; 12: Motor shaft; 13: Coupling; 14: Motor; 15: Sensor; 16: Solenoid valve. DETAILED DESCRIPTION

[0049] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention pertains. It should be understood that certain features of the present invention (described in the context of separate embodiments for clarity) may also be provided in combination in a single embodiment. On the contrary, a plurality of features of the present invention (described in the context of a single embodiment for brevity) may also be provided separately or in any suitable combination or in any other described embodiment of the present invention when appropriate. Certain features described in the context of various embodiments will not be considered as essential features of those embodiments unless the embodiment is inoperable without those elements. The present invention will be further described below by specific examples, but it should be noted that the specific process conditions and results described in the embodiments of the present invention are only used to illustrate the present invention and cannot limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and substance of the present invention should be included within the scope of protection of the present invention.

[0050] like Figure 1 As shown, the present invention provides a method for evaluating the motion accuracy retention of a mechanical transmission system, comprising the following steps:

[0051] S1. Based on the meta-action theory, the mechanical transmission system is structurally decomposed to obtain multiple meta-action units.

[0052] In this step, the mechanical transmission system is structurally decomposed using the meta-action theory, and the meta-action units obtained by decomposition are numbered in sequence according to the transmission direction of motion and power in the mechanical transmission system. For example, the meta-action units are numbered 1, 2, 3... to n, where n is a positive integer.

[0053] S2. Based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion unit, a motion error calculation model of the mechanical transmission system is constructed.

[0054] In this step, the precision degradation data of the meta-action units includes looseness data, wear data, deformation data, and aging data of the parts in two adjacent meta-action units. Specifically, the precision degradation data of this application is derived from the testing, use, and maintenance data of mechanical transmission systems or other mechanical products during actual operation. The above data can be selected and used from the enterprise or database.

[0055] In this step, the motion error generated by the upstream motion pair of the present application is affected by the transmission ratio of the downstream motion pair, and is finally accumulated to form the motion error of the mechanical transmission system.

[0056] Furthermore, the modeling process of this step is as follows: based on the motion error transmission mechanism of the mechanical transmission system and based on the accuracy degradation data of the elementary action units, the time-varying characteristic quantities and their degradation rates of two adjacent elementary action units, as well as the characteristic quantities that do not vary with time, are analyzed to determine the motion error of the kinematic pair consisting of the power output and power input components of the two adjacent elementary action units;

[0057] The transmission ratio of the kinematic pair consisting of the power output and power input parts of two adjacent elementary action units is obtained, and a kinematic error calculation model of the mechanical transmission system is constructed based on the kinematic error and transmission ratio of the kinematic pair.

[0058] Furthermore, since the motion error of the kinematic pair composed of the power output and power input parts of two adjacent elementary action units comes from the accuracy degradation data of the relevant parts in the adjacent elementary action units, then at any time t, the motion error ψ of the kinematic pair composed of the power output and power input parts of the two adjacent elementary action units is m-1,m The expression 1 is as follows:

[0059] ψ m-1,m =ψ[α m ,β m (t),α m-1 ,β m-1 (t)] (Equation 1)

[0060] In formula 1, ψ m-1,m Represents the motion error of the kinematic pair consisting of the power output component of the m-1th elementary action unit and the power input component of the mth elementary action unit;

[0061] α m Indicates the characteristic quantity that does not change with time in the power input component of the m-th element action unit during the calculation of the motion error of the motion pair;

[0062] α m-1 Indicates the characteristic quantity of the power output component of the m-1th element action unit that does not change with time during the calculation of the motion error of the motion pair;

[0063] β m (t) represents the characteristic quantity of the power input component of the m-th element action unit that changes with time during the calculation of the motion error of the motion pair;

[0064] β m-1 (t) represents the characteristic quantity of the power output component of the m-1th element action unit that changes with time during the calculation of the motion error of the motion pair.

[0065] Among them, if the power input component of the m-th element action unit contains k time-invariant feature quantities, and the power output component of the m-1-th element action unit contains h time-invariant feature quantities, then αm Satisfies the following expression 2, α m-1 The following expression 3 is satisfied:

[0066] α m =(α m,1 ,α m,2 ,......,α m,k ) (Formula 2)

[0067] α m-1 =(α m-1,1 ,α m-1,2 ,......,α m-1,h ) (Formula 3)

[0068] If the power input of the m-th element action unit contains p time-varying feature quantities, and the power output of the m-1-th element action unit contains q time-varying feature quantities, then β m (t) satisfies the following expression 4, β m-1 (t) satisfies the following Expression 5:

[0069]

[0070] In formula 4, represents the initial value of the p-th time-varying characteristic quantity in the power input component of the m-th element action unit; β m,p ·t represents the degradation rate of the pth time-varying characteristic quantity in the power input component of the mth element action unit.

[0071] In formula 5, represents the initial value of the qth time-varying characteristic quantity in the power output component of the m-1th element action unit; β m-1,q ·t represents the degradation rate of the qth characteristic quantity in the power output component of the m-1th element motion unit that changes with time.

[0072] Furthermore, based on the above equations 1 to 5, the motion error calculation model of the mechanical transmission system has the motion error ψ MTS The calculation expression 6 is as follows:

[0073]

[0074] In formula 6, when j=m, i j+1,j It represents the transmission ratio of the kinematic pair composed of the output input member of the m-th element action unit and the input and output member of the m-1-th element action unit; n represents the number of element action units included in the mechanical transmission system.

[0075] Furthermore, based on Equation 6, at any time t, the time-varying motion error ψ of the motion error calculation model of the mechanical transmission system is MTS(t) Calculate Expression 7 as follows:

[0076]

[0077] S3. Use the motion error calculation model to determine the initial motion error, maximum allowable motion error, and time-varying motion error of the mechanical transmission system.

[0078] In this step, the motion error of the kinematic pair is only related to the two adjacent meta-action units and internal parts, and the assembly and analysis processes of any two meta-action units are independent of each other. The characteristic quantity in each meta-action unit only affects the power input and power output parts of the meta-action unit.

[0079] In this step, the initial motion error is positively correlated with the machining error of the parts in the meta-motion unit and the assembly error of the meta-motion unit. The larger the machining error and assembly error, the larger the initial motion error. The maximum allowable error is determined by the design requirements of the mechanical transmission system.

[0080] Furthermore, based on the motion error calculation model, the initial motion error of this application is The maximum permissible motion error is [ψ MTS ].

[0081] S4. Based on the initial motion error and the maximum allowable motion error, a motion accuracy margin calculation model for the mechanical transmission system is constructed.

[0082] In this step, the modeling process includes: determining the motion accuracy margin of the mechanical transmission system, wherein the motion accuracy margin is the difference between the maximum motion error and the initial motion error.

[0083] Furthermore, the motion accuracy margin in the motion accuracy margin calculation model of the mechanical transmission system is The calculation expression 8 is as follows:

[0084]

[0085] S5. Use the motion accuracy margin calculation model, initial motion error, and time-varying motion error to construct a motion accuracy retention calculation model for the mechanical transmission system, and evaluate the motion accuracy retention of the mechanical transmission system based on the motion accuracy retention calculation model.

[0086] In this step, the modeling process is as follows:

[0087] Determining a degradation amount of motion accuracy of the mechanical transmission system, wherein the degradation amount is the difference between the motion error at any moment and the initial motion error;

[0088] Determining a motion accuracy margin residual value of the mechanical transmission system based on the motion accuracy margin and the degradation amount, wherein the motion accuracy margin residual value is a difference between the motion accuracy margin and the degradation amount;

[0089] Based on the motion accuracy margin remaining value and the motion accuracy margin, a motion accuracy retention degree of the mechanical transmission system is determined, wherein the motion accuracy retention degree is a ratio of the motion accuracy margin remaining value to the motion accuracy margin.

[0090] Furthermore, at any time t, the motion accuracy retention calculation model of the mechanical transmission system has the motion retention AR MTS The calculation expression 9 of (t) is as follows:

[0091]

[0092] In formula 9, Indicates the degradation of the motion accuracy of the mechanical transmission system; Indicates the residual value of the motion accuracy margin of the mechanical transmission system.

[0093] Furthermore, Figure 2 As shown, the analysis process of the method for evaluating the motion accuracy retention of the mechanical transmission system of this application is as follows:

[0094] This application first uses the meta-action theory to decompose the structure of the mechanical transmission system to obtain meta-action units, and then numbers the meta-action units according to the transmission direction of the power transmission process of the mechanical transmission system;

[0095] Then, based on the accuracy degradation data of the elementary action units, the transmission ratio of the kinematic pairs consisting of the power output and power input parts of two adjacent elementary action units, and the kinematic errors of the kinematic pairs, a time-varying kinematic error model of the kinematic pairs between the elementary action units (as shown in Equations 1 to 5) and a kinematic error model of the mechanical transmission system (as shown in Equation 6) are established. Furthermore, a time-varying kinematic error model of the mechanical transmission system (as shown in Equation 7) is established through the kinematic pair time-varying kinematic error model and the kinematic error model.

[0096] Based on the time-varying motion error model of the mechanical transmission system, the initial motion error and the maximum allowable motion error of the mechanical transmission system are obtained, thereby determining the motion accuracy margin of the mechanical transmission system (as shown in Equation 8);

[0097] Finally, based on the motion accuracy margin of the mechanical transmission system, the time-varying motion accuracy retention of the mechanical transmission system is calculated (as shown in Equation 9), and the motion accuracy retention evaluation of the mechanical transmission system is completed based on the motion accuracy retention.

[0098] like Figure 3 As shown, the present invention also provides a mechanical transmission system motion accuracy retention evaluation system, comprising:

[0099] A decomposition module 100 is used to decompose the structure of the mechanical transmission system based on the meta-action theory to obtain multiple meta-action units;

[0100] A first modeling module 200 is used to construct a motion error calculation model of the mechanical transmission system based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion units;

[0101] an error determination module 300 for determining an initial motion error, a maximum allowable motion error, and a time-varying motion error of the mechanical transmission system using a motion error calculation model;

[0102] The second modeling module 400 is used to construct a motion accuracy margin calculation model of the mechanical transmission system based on the initial motion error and the maximum allowable motion error;

[0103] The evaluation module 500 is used to construct a motion accuracy retention calculation model of the mechanical transmission system using the motion accuracy margin calculation model, the initial motion error and the time-varying motion error, and evaluate the motion accuracy retention of the mechanical transmission system based on the motion accuracy retention calculation model.

[0104] Furthermore, the system also includes an acquisition module for acquiring precision degradation data of the meta-action unit, and the precision degradation data includes looseness data, wear data, deformation data and aging data of parts in two adjacent meta-action units.

[0105] Furthermore, this application provides the following specific implementation methods to further illustrate the above evaluation method.

[0106] like Figure 4 As shown, the mechanical transmission system of this embodiment is a CNC turntable system, which includes the following components: base 1, turbine 2, main shaft 3, worktable 4, bearing 5, piston 6, brake pad 7, worm 8, intermediate gear 9, support plate 10, motor gear 11, motor shaft 12, coupling 13, motor 14, sensor 15, and solenoid valve 16.

[0107] Furthermore, according to the functions and characteristics of the CNC turntable system, the CNC turntable system is decomposed using the meta-action theory to obtain three meta-action units. Figure 5 and Figure 6 As shown in the figure, according to the transmission direction of motion and power in the CNC turntable system, the three meta-action units obtained by decomposition are numbered in sequence, with number A1 being the motor gear rotation meta-action unit, A2 being the worm rotation meta-action unit, and A3 being the worktable rotation meta-action unit.

[0108] Furthermore, at any time t, the motion error calculation expressions of the gear pair composed of the power output of the A1 motor gear rotating element action unit and the power input of the A2 worm rotating element action unit, and the worm gear pair composed of the power output of the A2 worm rotating element action unit and the power input of the A3 worktable rotating element action unit are calculated. Among them, the expression 10 of the gear pair composed of the A1 power output and the A2 power input at time t is as follows:

[0109] Ψ 1,2 =ψ[α1,β1(t),α2,β2(t)] (Formula 10)

[0110] In formula 10, ψ 1,2 Represents the motion error of the kinematic pair consisting of the power output component A1 and the power input component A2;

[0111] α2 represents the characteristic quantity of the power input component of A2 that does not change with time during the calculation of the motion error of the kinematic pair;

[0112] α1 represents the characteristic quantity of the power output component of A1 that does not change with time during the calculation of the motion error of the kinematic pair;

[0113] β2(t) represents the characteristic quantity of the power input component of A2 that changes with time during the calculation of the motion error of the kinematic pair;

[0114] β1(t) represents the characteristic quantity of the power output component of A1 that changes with time during the calculation of the motion error of the kinematic pair.

[0115] Among them, the power input component of A2 contains three feature quantities that do not change with time, and the power output component of A1 contains three feature quantities that do not change with time. Then α2 satisfies the following expression 11, and α1 satisfies the following expression 12:

[0116] α2=(α 2,1 ,α 2,2 ,α 2,3 ) (Formula 11)

[0117] α1=(α 1,1 ,α 1,2 ,α 1,3 ) (Formula 12)

[0118] In formula 11, α 2,1 Represents the tangential comprehensive error of the intermediate gear, α 2,2 Indicates the comprehensive tangential error between the teeth of the intermediate gear; α 2,3 Indicates the runout error of the shaft diameter where the intermediate gear is installed.

[0119] In formula 12, α 1,1 Represents the tangential comprehensive error of the motor gear, α1,2 Indicates the combined tangential error between the motor gear teeth, α 1,3 Indicates the runout error of the shaft diameter where the electrode gear is installed.

[0120] The power input component of A2 contains three time-varying feature quantities, and the power output component of A1 contains two time-varying feature quantities. Then β2(t) satisfies the following expression 13, and β1(t) satisfies the following expression 14:

[0121]

[0122] In formula 13, Represents the time-varying clearance error between the intermediate gear hole and the shaft; Represents the time-varying radial wear error of the needle roller bearing; Represents the time-varying clearance error of the worm shaft hole.

[0123] In formula 14, Indicates the time-varying clearance error between the motor gear hole and the shaft; Represents the time-varying radial wear error of a deep groove ball bearing.

[0124] Furthermore, at any time t, the motion error calculation expression 15 of the worm gear pair composed of the power output component of the A2 worm rotating element action unit and the power input component of the A3 worktable rotating element action unit is as follows:

[0125] Ψ 2,3 =ψ[α2,β2(t),α3,β3(t)] (Formula 15)

[0126] In formula 15, Ψ 2,3 Represents the motion error of the kinematic pair composed of the power output component A2 and the power input component A3;

[0127] α3 represents the characteristic quantity of the power input component of A3 that does not change with time during the calculation of the motion error of the kinematic pair;

[0128] α2 represents the characteristic quantity of the power output component of A2 that does not change with time during the calculation of the motion error of the kinematic pair;

[0129] β3(t) represents the characteristic quantity of the power input component of A3 that changes with time during the calculation of the motion error of the kinematic pair;

[0130] β2(t) represents the characteristic quantity of the power output component of A2 that changes with time during the calculation of the motion error of the kinematic pair.

[0131] Wherein, α3 satisfies the following expression 16, and α2 satisfies the following expression 17:

[0132] α3=(α3,1 ,α 3,2 ) (Equation 16)

[0133] α2=(α 2,4 ,α 2,5 ) (Equation 17)

[0134] In formula 16, α 3,1 Represents the tangential comprehensive error of the worm gear, α 3,2 Indicates the eccentricity error of the worm gear shaft.

[0135] In formula 17, α 2,4 represents the worm helix error, α 2,5 Indicates the eccentricity error of the worm shaft.

[0136] Where β3(t) satisfies the following expression 18, and β2(t) satisfies the following expression 19:

[0137]

[0138] In formula 18, Represents the time-varying clearance error of the worm gear shaft hole; Represents the time-varying radial wear error of the bearing.

[0139] In formula 19, Represents the time-varying radial wear error of the needle roller bearing; Represents the time-varying clearance error of the worm shaft hole; Indicates the time-varying tooth profile error caused by worm tooth surface wear.

[0140] Furthermore, based on Equations 11 to 19, at any time t, the time-varying motion error ψ of the motion error calculation model of the CNC turntable system is RTS (t) Calculation expression 20 is as follows:

[0141]

[0142] Furthermore, at any time t, the calculation expression 21 for the motion accuracy maintenance degree of the CNC turntable system is as follows:

[0143]

[0144] In formula 21, Indicates the initial rotation error of the CNC turntable system; Indicates the degradation of the rotation accuracy of the CNC turntable system; Indicates the residual value of the rotation accuracy margin of the CNC rotary table system; Indicates the rotation accuracy margin of the CNC turntable system.

[0145] Furthermore, this embodiment quantitatively evaluates the motion accuracy retention of the CNC turntable system based on Formula 21.

[0146] It should be noted that the mechanical transmission system motion accuracy retention assessment system provided in the above embodiment and the mechanical transmission system motion accuracy retention assessment method provided in the above embodiment are based on the same concept. The specific manner in which each module and unit performs operations has been described in detail in the method embodiment and will not be repeated here. In actual applications, the mechanical transmission system motion accuracy retention assessment system provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the system into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0147] An embodiment of the present application also provides a computer device, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the computer device implements the method for evaluating the motion accuracy retention of a mechanical transmission system provided in the above-mentioned embodiments.

[0148] Figure 7 The following is a schematic diagram showing the structure of a computer system suitable for a computer device according to an embodiment of the present application. Figure 7 The computer system 700 of the electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0149] like Figure 7As shown, computer system 700 includes a central processing unit (CPU) 701, which can perform various appropriate actions and processes according to programs stored in read-only memory (ROM) 702 or programs loaded from storage unit 708 into random access memory (RAM) 703, such as executing the methods described in the above embodiments. RAM 703 also stores various programs and data required for system operation. CPU 701, ROM 702, and RAM 703 are connected to each other via bus 704. An input / output (I / O) interface 705 is also connected to bus 704. The following components are connected to I / O interface 705: an input section 706 including a keyboard, mouse, etc.; an output section 707 including a cathode ray tube (CRT), liquid crystal display (LCD), speakers, etc.; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN (local area network) card or modem. Communication section 709 performs communication processing via a network such as the Internet. A driver 710 is also connected to I / O interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like, is mounted on the drive 710 as needed, so that a computer program read therefrom is installed into the storage portion 708 as needed.

[0150] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer tool program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 709, and / or installed from the removable medium 711. When the computer program is executed by the central processing unit (CPU) 701, the various functions defined in the system of the present application are executed.

[0151] It should be noted that the computer-readable medium described in the embodiments of this application may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may, for example, be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory, read-only memory, erasable programmable read-only memory, flash memory, optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination thereof. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying a computer-readable computer program. This propagated data signal may take a variety of forms, including, but not limited to, an electromagnetic signal, an optical signal, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transfer a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. The computer program embodied on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, etc., or any suitable combination of the foregoing.

[0152] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. Among them, each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0153] The units involved in the embodiments described in this application can be implemented by tools or hardware, and the units described can also be set in a processor. In some cases, the names of these units do not constitute limitations on the units themselves.

[0154] Another aspect of the present application provides a computer-readable storage medium having a computer program stored thereon. When executed by a computer processor, the computer program causes the computer to perform the aforementioned method for evaluating the kinematic accuracy retention of a mechanical transmission system. The computer-readable storage medium may be included in the computer device described in the above embodiments, or may exist independently and not be incorporated into the computer device.

[0155] Another aspect of the present application provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method for evaluating the kinematic accuracy retention of a mechanical transmission system provided in each of the above embodiments.

[0156] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for evaluating the motion accuracy retention of a mechanical transmission system, characterized in that: The steps include: S1. Based on the meta-action theory, the mechanical transmission system is decomposed to obtain multiple meta-action units; S2. Construct a motion error calculation model for the mechanical transmission system based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion units; Constructing a motion error calculation model for a mechanical transmission system includes: Based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion units, the time-varying characteristic quantities and their degradation rates, as well as the characteristic quantities that do not vary with time, of two adjacent elementary motion units are analyzed to determine the motion error of the kinematic pair consisting of the power output and power input components of the two adjacent elementary motion units. Obtaining the transmission ratio of the kinematic pair consisting of the power output and power input components of two adjacent elementary action units, and constructing a kinematic error calculation model of the mechanical transmission system based on the kinematic error and transmission ratio of the kinematic pair; S3. Determine the initial motion error, maximum allowable motion error, and time-varying motion error of the mechanical transmission system using the motion error calculation model; S4. Construct a motion accuracy margin calculation model for the mechanical transmission system based on the initial motion error and the maximum allowable motion error; The calculation model of motion accuracy margin of mechanical transmission system includes: Determining a kinematic accuracy margin of the mechanical transmission system, wherein the kinematic accuracy margin is the difference between a maximum kinematic error and an initial kinematic error; S5. Use the motion accuracy margin calculation model, initial motion error, and time-varying motion error to construct a motion accuracy retention calculation model for the mechanical transmission system. Based on the motion accuracy retention calculation model, evaluate the motion accuracy retention of the mechanical transmission system. The calculation model for the motion accuracy retention of a mechanical transmission system includes: Determining a degradation amount of motion accuracy of the mechanical transmission system, wherein the degradation amount is the difference between the motion error at any moment and the initial motion error; Determining a motion accuracy margin residual value of the mechanical transmission system based on the motion accuracy margin and the degradation amount, wherein the motion accuracy margin residual value is a difference between the motion accuracy margin and the degradation amount; Based on the motion accuracy margin remaining value and the motion accuracy margin, a motion accuracy retention degree of the mechanical transmission system is determined, wherein the motion accuracy retention degree is a ratio of the motion accuracy margin remaining value to the motion accuracy margin.

2. The evaluation method according to claim 1, wherein: The precision degradation data of the meta-action unit in step S2 includes looseness data, wear data, deformation data and aging data of parts in two adjacent meta-action units.

3. The evaluation method according to claim 1 or 2, characterized in that: The initial motion error in step S3 is positively correlated with the machining error of the parts in the meta-action unit and the assembly error of the meta-action unit.

4. A mechanical transmission system motion accuracy retention evaluation system, characterized in that: include: Decomposition module, used to decompose the structure of the mechanical transmission system based on the meta-action theory to obtain multiple meta-action units; The first modeling module is used to construct a motion error calculation model of the mechanical transmission system based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion unit; Constructing a motion error calculation model for a mechanical transmission system includes: Based on the motion error transmission mechanism of the mechanical transmission system and the accuracy degradation data of the elementary motion units, the time-varying characteristic quantities and their degradation rates, as well as the characteristic quantities that do not vary with time, of two adjacent elementary motion units are analyzed to determine the motion error of the kinematic pair consisting of the power output and power input components of the two adjacent elementary motion units. Obtaining the transmission ratio of the kinematic pair consisting of the power output and power input components of two adjacent elementary action units, and constructing a kinematic error calculation model of the mechanical transmission system based on the kinematic error and transmission ratio of the kinematic pair; an error determination module, for determining an initial motion error, a maximum allowable motion error, and a time-varying motion error of a mechanical transmission system using a motion error calculation model; The second modeling module is used to construct a motion accuracy margin calculation model of the mechanical transmission system based on the initial motion error and the maximum allowable motion error; The calculation model of motion accuracy margin of mechanical transmission system includes: Determining a kinematic accuracy margin of the mechanical transmission system, wherein the kinematic accuracy margin is the difference between a maximum kinematic error and an initial kinematic error; An evaluation module is used to construct a motion accuracy retention calculation model of the mechanical transmission system using a motion accuracy margin calculation model, an initial motion error, and a time-varying motion error, and to evaluate the motion accuracy retention of the mechanical transmission system based on the motion accuracy retention calculation model; The calculation model for the motion accuracy retention of a mechanical transmission system includes: Determining a degradation amount of motion accuracy of the mechanical transmission system, wherein the degradation amount is the difference between the motion error at any moment and the initial motion error; Determining a motion accuracy margin residual value of the mechanical transmission system based on the motion accuracy margin and the degradation amount, wherein the motion accuracy margin residual value is a difference between the motion accuracy margin and the degradation amount; Based on the motion accuracy margin remaining value and the motion accuracy margin, a motion accuracy retention degree of the mechanical transmission system is determined, wherein the motion accuracy retention degree is a ratio of the motion accuracy margin remaining value to the motion accuracy margin.

5. The evaluation system according to claim 4, wherein: It also includes an acquisition module for acquiring precision degradation data of the meta-action unit, where the precision degradation data includes looseness data, wear data, deformation data and aging data of parts in two adjacent meta-action units.

6. A computer-readable storage medium, characterized in that Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the method for evaluating the kinematic accuracy retention of a mechanical transmission system according to any one of claims 1 to 3.

7. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for evaluating the motion accuracy retention of a mechanical transmission system according to any one of claims 1 to 3 when executing the computer program.

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