Topological structure parameter optimization method and system for ultra-precise vertical five-axis machining center

Abstract

The invention provides a topological structure parameter optimization method and system for an ultra-precise vertical five-axis machining center, and the method comprises the steps: enabling each structural part in a to-be-optimized machine tool to be equivalent to a corresponding rigid hollow cuboid, and constructing a dynamic matrix corresponding to the rigid hollow cuboid; constructing a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joint parts among the sub-structural parts based on the connection relationship among the sub-structural parts in each structural part; based on a Lagrange equation, obtaining a target structure dynamic matrix according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; according to the series kinematic chain, the degree of freedom of connection points between the substructural parts is determined; according to the target structure dynamic matrix and the degree of freedom of the connection points, a kinetic equation of the ultra-precise vertical five-axis machining center is constructed, kinetic simulation is conducted according to the to-be-optimized topological structure parameters of the to-be-optimized machine tool, and a kinetic parameter optimization result is obtained. According to the invention, the ultra-precise vertical five-axis machining center has higher machining precision.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool equipment design and manufacturing, and in particular to a method and system for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center. Background Art

[0002] Ultra-precision vertical five-axis machining centers are indispensable core equipment in many high-tech fields. They are widely used in laser nuclear fusion research, aerospace technology, biomedical equipment manufacturing, optical mold processing and other industries. They can not only meet the needs of precision and ultra-precision machining, but also efficiently complete the drilling of tiny holes. They are an important force in promoting scientific and technological progress and industrial upgrading.

[0003] In terms of technology accumulation, the ultra-precision vertical five-axis machining center has made significant progress in many key technical fields, including hydrostatic drive design, which ensures the stability and efficiency of the equipment during operation; bed structure design, which ensures the high rigidity and durability of the machine tool; and constant temperature management and cooling system, which effectively controls thermal deformation during processing and improves processing accuracy. In addition, the advanced CNC system also provides a solid foundation for the automation and intelligence of the equipment.

[0004] However, in the frontier exploration of machine tool equipment design, there are still bottlenecks that need to be further broken through. In particular, the current challenges are particularly prominent in determining the optimal configuration of machine tool equipment and optimizing its topological structure parameters. In order to meet the stringent requirements of high acceleration and high precision, the overall structural design of machine tool equipment and the parameter configuration of each component require more sophisticated calculation and optimization, which is not only related to the processing performance and stability of the equipment, but also directly affects the quality and competitiveness of its final product. Therefore, there is an urgent need for a topological structure parameter optimization method and system for ultra-precision vertical five-axis machining centers to solve the above problems. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method and system for optimizing the topological structure parameters of an ultra-precision vertical five-axis machining center.

[0006] The present invention provides a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center, comprising: Each structural part in the machine tool to be optimized is equivalent to a corresponding rigid hollow cuboid, and the center of mass of the rigid hollow cuboid is used as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; Based on the connection relationship between the sub-structures in each of the structural parts of the machine tool to be optimized, a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structures in each of the structural parts are constructed, wherein the flexible joints are flexible connection sub-structures with six degrees of freedom in space; Based on the Lagrange equation, the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized is calculated according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; Determining the degrees of freedom of connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members; According to the target structure dynamic matrix and the connection point degrees of freedom, the dynamic equation of the ultra-precision vertical five-axis machining center is constructed, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, dynamic simulation is performed according to the topological structure parameters to be optimized of the machine tool to be optimized, and the dynamic parameter optimization results corresponding to the machine tool to be optimized are obtained.

[0007] According to a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention, the method further comprises: According to the movement mode and structural component composition information of each of the structural components in the machine tool to be optimized, the sub-structural components in each of the structural components in the machine tool to be optimized are divided into fixed sub-structural components and feed shaft sub-structural components, wherein the fixed sub-structural components are sub-structural components in the machine tool to be optimized where no feed motion occurs; and the feed shaft sub-structural components include moving sub-structural components and feed transmission sub-structural components.

[0008] According to a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention, the centroid of the rigid hollow cuboid is used as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, including: Taking the center of mass of the rigid hollow cuboid as the origin, constructing a local coordinate system corresponding to the rigid hollow cuboid; Based on the local coordinate system, the dynamic matrix corresponding to the rigid hollow cuboid is constructed according to the mass information and moment of inertia of the rigid hollow cuboid, wherein the mass information is calculated based on the mass information of the solid outer cuboid and the mass information of the hollow inner cavity cuboid of the rigid hollow cuboid; and the moment of inertia is calculated based on the moment of inertia information of the solid outer cuboid and the moment of inertia information of the hollow inner cavity cuboid of the rigid hollow cuboid.

[0009] According to a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention, based on the connection relationship between the sub-structures in each of the structural parts of the machine tool to be optimized, a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structures in each of the structural parts are constructed, including: Determining the flexible joints between the sub-structures in each of the structural members of the machine tool to be optimized based on the connection relationship between the sub-structures in each of the structural members; The flexible joint is equivalent to a six-way flexible connection substructure, wherein the six-way flexible connection substructure is composed of a six-degree-of-freedom spring damping unit, a first connection node and a second connection node; the first connection node and the second connection node are massless nodes, and the mass matrix corresponding to the six-way flexible connection substructure is a 12th-order zero matrix; The stiffness matrix and the damping matrix are constructed based on the translational stiffness, rotational stiffness, translational damping and rotational damping corresponding to the six-degree-of-freedom spring-damper unit.

[0010] According to a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention, the target structural dynamic matrix corresponding to each structural component of the machine tool to be optimized is calculated based on the Lagrange equation according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix, including: Obtaining the generalized coordinates corresponding to the flexible joint in a twelve-degree-of-freedom dynamic system; Based on the Lagrange equation, according to the deformation of the six-degree-of-freedom spring damping unit and the generalized coordinates, respectively calculate the target dynamic matrix corresponding to the dynamic matrix in the twelve-degree-of-freedom power system, the target mass matrix corresponding to the mass matrix in the twelve-degree-of-freedom power system, the target stiffness matrix corresponding to the stiffness matrix in the twelve-degree-of-freedom power system, and the target damping matrix corresponding to the damping matrix in the twelve-degree-of-freedom power system; The target structural dynamic matrix is ​​obtained according to the target dynamic matrix, the target mass matrix, the target stiffness matrix and the target damping matrix.

[0011] According to a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention, the degree of freedom of connection points between the sub-structures in each of the structural parts is determined according to the serial kinematic chain formed by the sub-structures in each of the structural parts, including: Acquire motion trajectory information of connection points between the sub-structures in the serial kinematic chain in the global coordinate system of the machine tool to be optimized; Based on the preset topological relationship sequence numbers of the sub-structures in the machine tool to be optimized, determining the target sub-structure and the rigid body degrees of freedom corresponding to the target sub-structure; wherein the target sub-structure is the first k sub-structures selected in ascending order based on the preset topological relationship sequence numbers; A relationship matrix between the rigid body degrees of freedom corresponding to the target sub-structure and the motion trajectory information is constructed, and the degrees of freedom of the connection points between the sub-structures in each of the structures are determined according to the rigid body degrees of freedom corresponding to the target sub-structure and the relationship matrix.

[0012] According to a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention, the dynamic equation of the ultra-precision vertical five-axis machining center is constructed according to the target structure dynamic matrix and the connection point degrees of freedom, including: Based on the displacement coordination and force balance conditions, according to the connection relationship between the various structural parts, the various target dynamic matrices are connected through the connection matrix to obtain the connected target dynamic matrix; the various target mass matrices are connected through the connection matrix to obtain the connected target mass matrix; the various target stiffness matrices are connected through the connection matrix to obtain the connected target stiffness matrix; the various target damping matrices are connected through the connection matrix to obtain the connected target damping matrix; The dynamic equation of the ultra-precision vertical five-axis machining center is constructed according to the target dynamic matrix after connection, the target mass matrix after connection, the target stiffness matrix after connection, the target damping matrix after connection and the degree of freedom of the connection point; The method further comprises: The oil film joint portion between the guide rail and the slider is equivalent to a one-way spring damping unit, and a first stiffness value is obtained according to the one-way spring damping unit and historical test data; Equivalently treating the contact parts between the machine tool bed, the column and the crossbeam as a three-way spring unit, and obtaining a second stiffness value according to the three-way spring unit and the historical test data; Calculating a third stiffness value based on mass information of a machine tool component supported by the air-floating vibration isolation unit and a natural frequency of the air-floating vibration isolation unit; Equivalently converting the cross roller bearing between the machine tool cradle and the machine tool turntable into a six-way spring unit, and acquiring a fourth stiffness value according to the six-way spring unit and the historical test data; The topological structure parameters to be optimized of the machine tool to be optimized are constructed according to the mass information and the moment of inertia of the rigid hollow cuboid, and the first stiffness value, the second stiffness value, the third stiffness value, and the fourth stiffness value.

[0013] The present invention also provides a topological structure parameter optimization system for an ultra-precision vertical five-axis machining center, comprising: The first processing module is used to convert each structural member in the machine tool to be optimized into a corresponding rigid hollow cuboid, and use the center of mass of the rigid hollow cuboid as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; A second processing module is used to construct a mass matrix, a stiffness matrix and a damping matrix corresponding to a flexible joint between the substructures in each of the structural parts of the machine tool to be optimized based on the connection relationship between the substructures in each of the structural parts, wherein the flexible joint is a flexible connection substructure with six degrees of freedom in space; A structural dynamic matrix calculation module, used for calculating the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized based on the Lagrange equation, according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; A third processing module is used to determine the degree of freedom of the connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members; A dynamics simulation processing module is used to construct a dynamics equation of an ultra-precision vertical five-axis machining center according to the target structure dynamic matrix and the connection point degrees of freedom, and based on the dynamics equation of the ultra-precision vertical five-axis machining center, perform dynamics simulation according to the topological structure parameters to be optimized of the machine tool to be optimized, so as to obtain the dynamics parameter optimization results corresponding to the machine tool to be optimized.

[0014] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for optimizing the topological structure parameters of an ultra-precision vertical five-axis machining center as described in any one of the above-mentioned methods is implemented.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center as described in any one of the above.

[0016] The topological structure parameter optimization method and system of the ultra-precision vertical five-axis machining center provided by the present invention establish a whole-machine multi-rigid body dynamic model of the ultra-precision vertical five-axis machining center with a fixed beam structure, and use the mass of structural parts, the center of mass position of structural parts and the stiffness of the joint of the guide rail and slider as the topological structure parameters to be optimized of the machine tool, thereby optimizing the ultra-precision vertical five-axis machining center with a fixed beam structure, providing a guarantee for the successful development of high-performance machine tools, and making the ultra-precision vertical five-axis machining center have higher machining accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 A schematic flow chart of a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention; Figure 2 A schematic diagram of a rigid hollow cuboid with six degrees of freedom in space provided by the present invention; Figure 3 A schematic diagram of the classification of machine tool structure types provided by the present invention; Figure 4 A schematic diagram of a six-way flexible connection substructure provided by the present invention; Figure 5 Schematic diagram of structural parts of axes in different directions provided by the present invention; Figure 6 A schematic diagram of an equivalent hollow cuboid of an X-axis motion structural member provided by the present invention; Figure 7 A schematic diagram of the relative positions of various structural components provided by the present invention; Figure 8 A schematic structural diagram of a hollow cuboid provided by the present invention; Fig. 9 A schematic structural diagram of a one-way spring damping unit provided by the present invention; Fig.10 A schematic structural diagram of a three-way spring unit provided by the present invention; Fig.11 A schematic diagram of the structure of a topological structure parameter optimization system for an ultra-precision vertical five-axis machining center provided by the present invention; Fig.12 This is a schematic structural diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Figure 1A schematic diagram of a process flow of a topological structure parameter optimization method for an ultra-precision vertical five-axis machining center provided by the present invention, such as Figure 1 As shown, the present invention provides a method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center, comprising: Step 101, equate each structural part in the machine tool to be optimized to a corresponding rigid hollow cuboid, and use the center of mass of the rigid hollow cuboid as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space.

[0021] In the present invention, in order to simplify and model the complex mechanical structure, a preset equivalent model is used to simplify the complex structural parts into geometric shapes that are easy to calculate and analyze. For the machine tool to be optimized, each structural part in the machine tool (such as the bed, column and workbench, etc.) can be equivalent to a corresponding rigid hollow cuboid. When these rigid hollow cuboids are subjected to force, these cuboids will not deform, that is, their shape and size remain unchanged. Figure 2 Schematic diagram of a rigid hollow cuboid with six degrees of freedom in space provided by the present invention. The present invention converts each structural member in the machine tool to be optimized into a corresponding rigid hollow cuboid. Figure 2 shown.

[0022] In the present invention, the setting of the cuboid being "hollow" is to be closer to reality, because many machine tool structural parts may contain cavities, channels or other non-solid parts inside, which have a certain impact on the overall dynamic performance. By considering the structural part as a hollow cuboid, the present invention can more accurately simulate its physical properties such as mass and moment of inertia.

[0023] Furthermore, in order to perform dynamic performance analysis, the present invention constructs dynamic matrices for these rigid hollow cuboids to describe the motion state of the object in space, including position, velocity, acceleration, etc. For a rigid hollow cuboid with six degrees of freedom in space, its dynamic matrix will contain six independent degrees of freedom: three translational degrees of freedom and three rotational degrees of freedom.

[0024] When constructing the dynamic matrix, the present invention uses the center of mass of each rigid hollow cuboid as the origin. The center of mass is the geometric center of the mass of the object and is also the balance point of the object's movement in space. Constructing the dynamic matrix with the center of mass as the origin can simplify the calculation process and make the result more accurate.

[0025] Step 102, based on the connection relationship between the sub-structures in each of the structural parts of the machine tool to be optimized, construct a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structures in each of the structural parts, wherein the flexible joints are flexible connection sub-structures with six degrees of freedom in space.

[0026] In the present invention, machine tool structural parts are the various large components that constitute the overall frame and support system of the machine tool, such as the bed, columns and beams, etc. These structural parts are the foundation of the machine tool, and their rigidity and stability directly affect the processing accuracy and performance of the machine tool. Sub-structural parts are smaller units or components that constitute the above-mentioned structural parts. For example, the bed may be made of multiple steel plates welded or bolted together, and these steel plates or connecting parts can be regarded as sub-structural parts. In addition, the sub-structural parts are not completely rigidly connected. Due to factors such as assembly clearance, material deformation, and the elasticity of connecting parts (such as bolts and welding), there is a certain flexibility between the sub-structural parts. This flexible connection is particularly important in dynamic analysis.

[0027] The six degrees of freedom in space refer to the six basic degrees of freedom of motion that an object can translate along three coordinate axes (X, Y, Z) and rotate around these three axes in space. The stiffness matrix describes the ability of a structure to resist deformation when subjected to external forces. In the dynamic analysis of machine tools, the stiffness matrix reflects the response characteristics of each substructure and its connection when subjected to dynamic loads (such as cutting forces). The damping matrix describes the energy dissipation capacity of the structure during vibration. Damping is an important factor in reducing vibration amplitude and accelerating vibration attenuation. In machine tool design, reasonable damping design can effectively improve the stability and processing accuracy of the machine tool.

[0028] Based on the above concepts, the present invention constructs the mass matrix, stiffness matrix and damping matrix corresponding to the flexible joints between the sub-structures in each structural part, so as to perform dynamic modeling on the machine tool. The specific process is as follows: First, it is necessary to clarify which parts of the machine tool are substructures and how they are connected. Then, the flexibility and damping characteristics of the connection are estimated based on the connection type (such as bolt connection, welding, etc.) and material properties. In the present invention, the flexible joints between substructures are equivalent to flexible connection substructures with six degrees of freedom in space, and then a mathematical model corresponding to the flexible connection substructure is constructed, including a mass matrix, a stiffness matrix, and a damping matrix, so as to obtain the dynamic response of the machine tool under specific excitation, evaluate its performance, and optimize the design.

[0029] Step 103, based on the Lagrange equation, according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix, calculate and obtain the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized.

[0030] In the dynamic performance analysis of machine tools, six degrees of freedom usually refer to the six basic degrees of freedom of motion in which an object can translate along three coordinate axes and rotate around these three axes in space. The twelve-degree-of-freedom system may involve more complex motion patterns, such as considering the relative motion between two or more objects. The dynamic matrix, mass matrix, stiffness matrix and damping matrix are key parameters for describing the dynamic characteristics of machine tools. The dynamic matrix may include the mass, inertia and other properties of the structural parts; the mass matrix is ​​a 12th-order zero matrix; the stiffness matrix reflects the system's ability to resist deformation; and the damping matrix describes the system's energy dissipation capacity during vibration.

[0031] In the present invention, since the original dynamic matrix, mass matrix, stiffness matrix and damping matrix are constructed based on a six-degree-of-freedom system, and the subsequent machine tool dynamics simulation analysis needs to be expanded to a twelve-degree-of-freedom system, the present invention applies the Lagrange equations to establish the dynamic model of the system, which involves expressing the kinetic energy and potential energy of the system as functions of generalized coordinates and generalized velocities, and deriving the motion equations of the system based on these functions.

[0032] Furthermore, the present invention can calculate the dynamic responses of various structural parts of the machine tool in the twelve-degree-of-freedom system by solving the motion equations obtained by solving the Lagrange equations. These responses can be expressed in the form of various dynamic matrices, such as displacement matrix, velocity matrix, acceleration matrix, etc. Among them, the target structure dynamic matrix describes the comprehensive matrix of the dynamic responses of various structural parts of the machine tool under specific excitation, which includes the system's mass, stiffness, damping and other characteristic information.

[0033] Step 104 : determining the degree of freedom of the connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members.

[0034] In the present invention, the substructures are connected in series through a specific connection method (such as bolts) to form a "serial kinematic chain". The "serial kinematic chain" is a series of substructures arranged in a specific order and connection method to form a continuous path that can transmit motion and force. In this path, each substructure has its own local coordinate system and degree of freedom. The degree of freedom refers to the number of parameters that an object can move independently in space. For a rigid body, it usually includes three translational degrees of freedom and three rotational degrees of freedom (a total of six degrees of freedom).

[0035] Since the local coordinate system and degrees of freedom of each substructure are relative to itself, in order to realize the assembly and dynamic analysis of the whole machine structure, it is necessary to convert these local degrees of freedom into a unified global coordinate system. In order to realize this conversion, the present invention determines the connection point degrees of freedom according to the interface degrees of freedom of each substructure in the series kinematic chain, wherein the interface degrees of freedom refer to the motion parameters allowed on the connection interface between substructures, and these motion parameters may include translation, rotation angle, etc., which determine how the substructures move relative to each other.

[0036] Specifically, in the present invention, it is first determined which substructures in the machine tool constitute a serial kinematic chain and how they are connected. For each substructure in the serial kinematic chain, the connection interface between it and the adjacent substructure is analyzed to determine which movements are allowed (i.e., interface degrees of freedom). Then, based on the analysis of the interface degrees of freedom, the degrees of freedom of each connection point can be calculated. These degrees of freedom may include translational degrees of freedom and rotational degrees of freedom, which describe the relative movement capabilities between substructures at the connection points. Finally, these connection point degrees of freedom are used to realize the conversion from the local coordinate system to the global coordinate system to ensure that the entire machine tool structure is dynamically analyzed and optimized in a unified global coordinate system.

[0037] Step 105, constructing the dynamic equation of the ultra-precision vertical five-axis machining center according to the target structure dynamic matrix and the connection point degrees of freedom, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, performing dynamic simulation according to the topological structure parameters to be optimized of the machine tool to be optimized, and obtaining the dynamic parameter optimization result corresponding to the machine tool to be optimized.

[0038] In the present invention, the dynamic equation of the ultra-precision vertical five-axis machining center takes into account all important dynamic characteristics of the machine tool to be optimized, including the dynamic response of each structural part, the flexibility of the connection part, the friction and stiffness of the guide rail slider, etc. This equation is a set of differential equations containing multiple variables and parameters, which describes the dynamic behavior of the machine tool under different working conditions.

[0039] The topological structure parameters to be optimized are the adjustable parts in the machine tool design, and the purpose is to improve the dynamic performance of the machine tool by optimizing these parameters. In the present invention, the topological structure parameters to be optimized include at least the mass of the structural parts, the center of mass position of the structural parts, and the stiffness of the guide rail and slider joint. Among them, the mass of the structural parts affects the overall inertia and dynamic response speed of the machine tool; the center of mass position of the structural parts affects the balance and stability of the machine tool. The stiffness of the guide rail and slider joint affects the stiffness and precision of the machine tool.

[0040] Furthermore, based on the constructed dynamic equations and the topological parameters to be optimized, dynamic simulation software is used for simulation, including model building, parameter setting, simulation operation and result analysis. Through simulation, the dynamic performance of the machine tool under different working conditions, such as vibration, noise, accuracy, etc., can be predicted. Finally, based on the simulation results, the influence of different topological parameters on the dynamic performance of the machine tool can be evaluated, and the optimal parameter combination can be found. These optimization results will guide the further design and improvement of the machine tool to improve its overall performance and accuracy.

[0041] The method for optimizing the topological structure parameters of an ultra-precision vertical five-axis machining center provided by the present invention establishes a multi-rigid body dynamics model of the ultra-precision vertical five-axis machining center with a fixed beam structure, and uses the mass of structural parts, the center of mass position of structural parts, and the stiffness of the joint of the guide rail and slider as the topological structure parameters to be optimized of the machine tool, thereby optimizing the ultra-precision vertical five-axis machining center with a fixed beam structure, providing a guarantee for the successful development of high-performance machine tools, and enabling the ultra-precision vertical five-axis machining center to have higher machining accuracy.

[0042] Based on the above embodiment, the method further includes: According to the movement mode and structural component composition information of each of the structural components in the machine tool to be optimized, the sub-structural components in each of the structural components in the machine tool to be optimized are divided into fixed sub-structural components and feed shaft sub-structural components, wherein the fixed sub-structural components are sub-structural components in the machine tool to be optimized where no feed motion occurs; and the feed shaft sub-structural components include moving sub-structural components and feed transmission sub-structural components.

[0043] Figure 3 The schematic diagram of the classification of the machine tool structure types provided by the present invention can be referred to Figure 3 As shown, in the present invention, the machine tool structural parts are the basis for forming the overall frame of the machine tool and supporting various functional components. These structural parts can be divided into different types according to their movement mode and composition information.

[0044] Fixed substructures refer to those substructures that do not undergo feed motion (or only undergo feed motion in a smaller range) during the operation of the machine tool. They usually support, fix and connect other moving parts, including key components such as the machine tool bed, columns and beams. Their stability and rigidity directly affect the overall performance and machining accuracy of the machine tool.

[0045] Feed axis substructures refer to those substructures that undergo feed motion during the operation of the machine tool, including motion substructures and feed transmission substructures. Among them, motion substructures are components that directly participate in the feed motion, such as worktables, slides, spindle boxes, etc. These components need to have high motion accuracy and dynamic response capabilities to ensure the feed accuracy and efficiency of the machine tool during the processing process. Feed transmission substructures are components used to transmit the power and motion of the feed motion, such as motors, lead screws, guide rails, etc. These components need to have high transmission accuracy and rigidity to ensure the stability and accuracy of the machine tool during the feed process.

[0046] In the present invention, by analyzing the working principle of the machine tool and the functions of each structural part in detail, it is possible to determine which structural parts are fixed and which structural parts are involved in the feed motion. At the same time, it is also necessary to consider the composition information of the structural parts, such as material, shape, size, etc., to ensure the accuracy and rationality of the division. The present invention divides the various structural parts in the machine tool to be optimized into fixed sub-structural parts and feed shaft sub-structural parts (including motion sub-structural parts and feed transmission sub-structural parts), which helps to better understand the working principle and dynamic characteristics of the machine tool, and provides strong support for subsequent optimization design and performance improvement.

[0047] On the basis of the above embodiment, the method of taking the center of mass of the rigid hollow cuboid as the origin and constructing a dynamic matrix corresponding to the rigid hollow cuboid includes: Taking the center of mass of the rigid hollow cuboid as the origin, constructing a local coordinate system corresponding to the rigid hollow cuboid; Based on the local coordinate system, the dynamic matrix corresponding to the rigid hollow cuboid is constructed according to the mass information and moment of inertia of the rigid hollow cuboid, wherein the mass information is calculated based on the mass information of the solid outer cuboid and the mass information of the hollow inner cavity cuboid of the rigid hollow cuboid; and the moment of inertia is calculated based on the moment of inertia information of the solid outer cuboid and the moment of inertia information of the hollow inner cavity cuboid of the rigid hollow cuboid.

[0048] In the present invention, after the structural member is equivalent to a rigid hollow cuboid with six degrees of freedom in space (i.e., a rigid hollow cuboid), a local coordinate system is established with the center of mass of the rigid hollow cuboid with six degrees of freedom in space as the origin, and then a dynamic matrix of the rigid hollow cuboid with six degrees of freedom in space is constructed. : ; in, represents the mass of the i-th rigid hollow cuboid, in kg; They represent the principal moments of inertia of the i-th rigid hollow cuboid along the x-axis, y-axis, and z-axis respectively.

[0049] Specifically, in the present invention, the center of mass of the rigid hollow cuboid is taken as the origin. After the origin is selected, three mutually perpendicular coordinate axes (usually X, Y, and Z axes) are defined to form a local coordinate system. The mass information of the solid outer cuboid refers to the mass of the material constituting the external entity of the rigid hollow cuboid. This part of the mass can be obtained by measurement or calculation, and is related to the size of the cuboid and the density of the material. In the present invention, there is a cavity inside the rigid hollow cuboid, so the space occupied by these cavities will also have a "virtual" mass, but the "mass" here actually refers to the mass if this part of the space is filled with solid material. Therefore, in actual situations, it is necessary to subtract this part of the cavity mass from the total mass. In the present invention, the total mass of the rigid hollow cuboid is obtained by subtracting the "virtual" mass of the hollow inner cavity from the mass of the solid outer cuboid (if the material density is considered to be consistent, the cavity volume multiplied by the density is directly subtracted).

[0050] Furthermore, the moment of inertia is a physical quantity that describes the magnitude of inertia when a rigid body rotates around a certain axis, and is related to the mass distribution of the rigid body and the position of the rotation axis. In the present invention, for the outer cuboid portion of the solid, the moment of inertia around any axis can be calculated using known formulas (such as the parallel axis theorem or the integral method), which usually involve the size, mass and position of the rotation axis of the cuboid.

[0051] Similarly, for the hollow inner part, its moment of inertia about the same axis is calculated and then used as the part that needs to be subtracted from the total moment of inertia (considering that the material density and the moment of inertia density are the same). Finally, the total moment of inertia of the rigid hollow cuboid is obtained by subtracting the moment of inertia of the hollow inner part from the moment of inertia of the solid outer cuboid.

[0052] In the present invention, the dynamic matrix is ​​a matrix containing the dynamic characteristics of a rigid body (such as mass and moment of inertia). In mechanical analysis, it is used to describe the motion equations and force conditions of a rigid body. Based on the calculated mass and moment of inertia information, the present invention can construct a dynamic matrix. For a rigid hollow cuboid, the dynamic matrix is ​​a symmetric matrix containing six elements (three mass elements and three moment of inertia elements).

[0053] On the basis of the above embodiment, the mass matrix, stiffness matrix and damping matrix corresponding to the flexible joints between the sub-structures in each of the structural parts of the machine tool to be optimized are constructed based on the connection relationship between the sub-structures in each of the structural parts, including: Determining the flexible joints between the sub-structures in each of the structural members of the machine tool to be optimized based on the connection relationship between the sub-structures in each of the structural members; The flexible joint is equivalent to a six-way flexible connection substructure, wherein the six-way flexible connection substructure is composed of a six-degree-of-freedom spring damping unit, a first connection node and a second connection node; the first connection node and the second connection node are massless nodes, and the mass matrix corresponding to the six-way flexible connection substructure is a 12th-order zero matrix; The stiffness matrix and the damping matrix are constructed based on the translational stiffness, rotational stiffness, translational damping and rotational damping corresponding to the six-degree-of-freedom spring-damper unit.

[0054] In the present invention, the flexible joint in the machine tool to be optimized is equivalent to a six-way flexible connection substructure model. Figure 4 A schematic diagram of a six-way flexible connection substructure provided by the present invention, such as Figure 4 As shown, the six-way flexible connection substructure is composed of a six-degree-of-freedom spring damping unit and two massless nodes (i.e., the first connection node and the second connection node). Each massless node has six degrees of freedom in space, which are expressed as and .

[0055] Furthermore, according to the relative coordinate definition, is relative to the local coordinate system In the present invention, the generalized coordinates of the six-way flexible connection substructure are , corresponding to a 12-DOF dynamic system. Figure 4 As shown, node 1 (i.e., the first connection node) connects the rigid connection point on the low-order body structure, and node 2 (i.e., the second connection node) connects the rigid connection point on the high-order body structure. It should be noted that, in the present invention, the low-order body structure and the high-order body structure are determined based on the preset topological relationship number of the sub-structure.

[0056] Furthermore, the six-way flexible connection substructure has only two massless nodes, and the corresponding mass matrix is a 12th-order zero matrix, the stiffness matrix and the damping matrix for: ; ; in, They represent the translational stiffness of the six-degree-of-freedom spring-damper unit along the X-axis, Y-axis, and Z-axis respectively; They represent the rotational stiffness of the six-degree-of-freedom spring-damper unit around the X-axis, Y-axis, and Z-axis respectively; They represent the translational damping of the six-degree-of-freedom spring damping unit along the X-axis, Y-axis, and Z-axis respectively; Represents the rotational damping of the six-degree-of-freedom spring-damper unit around the X-axis, Y-axis, and Z-axis.

[0057] In the present invention, the connection relationship between the various structural parts of the machine tool to be optimized is analyzed, including identifying which structural parts are connected together by bolts, welding, riveting or other means, and how these connections affect the overall stiffness and damping characteristics of the machine tool. Based on the analysis of the connection relationship, it can be determined which connection parts are flexible, that is, they will produce certain deformation and energy dissipation when subjected to force.

[0058] In order to simplify the analysis, the present invention equates each flexible joint to a six-way flexible connection substructure. This substructure can simulate the flexibility and damping characteristics of the connection part in six degrees of freedom (three translational degrees of freedom and three rotational degrees of freedom). The six-way flexible connection substructure consists of a six-degree-of-freedom spring damping unit, a first connection node and a second connection node, wherein the two connection nodes are massless and are used to connect adjacent structural members. The six-degree-of-freedom spring damping unit is used to simulate the flexibility and damping characteristics of the connection part.

[0059] Since the connection nodes are massless, the mass matrix corresponding to the six-way flexible connection substructure is a 12th-order zero matrix, so there is no need to consider the impact of the mass of the connection part itself on the dynamic performance of the machine tool. The six-degree-of-freedom spring damping unit has translational stiffness and rotational stiffness, as well as translational damping and rotational damping. These characteristics determine the deformation and energy dissipation of the connection part when it is subjected to force.

[0060] Furthermore, based on the characteristics of the six-degree-of-freedom spring-damper unit, the stiffness matrix and damping matrix of the six-way flexible connection substructure are constructed. These two matrices are used to describe the deformation and energy dissipation of the connection parts when subjected to force. In the dynamic performance analysis of the machine tool, these matrices can be integrated into the overall dynamic model of the machine tool. By solving this model, the response of the machine tool under specific excitation can be obtained, and then the structure of the machine tool can be optimized.

[0061] On the basis of the above embodiment, the target structural dynamic matrix corresponding to each structural part of the machine tool to be optimized is calculated based on the Lagrange equation according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix, including: Obtaining the generalized coordinates corresponding to the flexible joint in a twelve-degree-of-freedom dynamic system; Based on the Lagrange equation, according to the deformation of the six-degree-of-freedom spring damping unit and the generalized coordinates, respectively calculate the target dynamic matrix corresponding to the dynamic matrix in the twelve-degree-of-freedom power system, the target mass matrix corresponding to the mass matrix in the twelve-degree-of-freedom power system, the target stiffness matrix corresponding to the stiffness matrix in the twelve-degree-of-freedom power system, and the target damping matrix corresponding to the damping matrix in the twelve-degree-of-freedom power system; The target structural dynamic matrix is ​​obtained according to the target dynamic matrix, the target mass matrix, the target stiffness matrix and the target damping matrix.

[0062] In the present invention, since the flexible joint model connects rigid bodies, the flexible joint included in each structural member can be equivalent to a connection node with six degrees of freedom in space, which can be expressed as The present invention is explained by taking the substructure of the fixed structure as an example, and the typical flexible joint in the fixed structure is the joint of the anchor and the bolt, which is equivalent to a three-way linear spring damping unit. Based on the above equivalent model, this type of joint structure is a 12-degree-of-freedom dynamic system, and its generalized coordinates are: ; According to the relative coordinate definition, For rigid body The displacement of the equivalent spring damping unit of the flexible joint for: ; in, Represents the position coordinates of the i-th spring-damper unit relative to the center of mass of the structural component.

[0063] Furthermore, using the Lagrange equation, the target structure dynamic matrix is ​​obtained as shown below; .

[0064] Specifically, in dynamic analysis, generalized coordinates are variables used to describe the state of a system. For a 12-DOF dynamic system with flexible joints, it is necessary to define the generalized coordinates of each flexible joint in the system. These coordinates may include the displacement (translation and rotation) of the connection and the related velocity, acceleration, etc.

[0065] Since the flexible joints may be located in different parts of the system and their motion may involve multiple degrees of freedom, it is necessary to transform these coordinates into a unified reference system for subsequent analysis and calculation. Accordingly, the dynamic matrix of the rigid hollow cuboid with six degrees of freedom in space also needs to calculate the corresponding target dynamic matrix. There is a direct relationship between the deformation of the six-degree-of-freedom spring damping unit (i.e., the relative displacement and rotation of the connection part) and the generalized coordinates. By measuring or calculating these deformations, they can be converted into functions of generalized coordinates.

[0066] Based on the Lagrange equation and the deformation of the six-degree-of-freedom spring damping unit, the present invention can respectively calculate the target matrices corresponding to the dynamic matrix, mass matrix, stiffness matrix and damping matrix in the twelve-degree-of-freedom dynamic system, and these target matrices describe the dynamic characteristics of the six-degree-of-freedom rigid hollow cuboid and the flexible joint in the system, including its stiffness, damping and interaction with other structural parts. After calculating the target dynamic matrix, target stiffness matrix and target damping matrix, these matrices need to be integrated into the overall dynamic model of the machine tool structure to form a complete matrix that describes the overall dynamic characteristics of the machine tool.

[0067] On the basis of the above embodiment, the step of determining the degrees of freedom of connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members includes: Acquire motion trajectory information of connection points between the sub-structures in the serial kinematic chain in the global coordinate system of the machine tool to be optimized; Based on the preset topological relationship sequence numbers of the sub-structures in the machine tool to be optimized, determining the target sub-structure and the rigid body degrees of freedom corresponding to the target sub-structure; wherein the target sub-structure is the first k sub-structures selected in ascending order based on the preset topological relationship sequence numbers; A relationship matrix between the rigid body degrees of freedom corresponding to the target sub-structure and the motion trajectory information is constructed, and the degrees of freedom of the connection points between the sub-structures in each of the structures are determined according to the rigid body degrees of freedom corresponding to the target sub-structure and the relationship matrix.

[0068] In the above embodiment, the degrees of freedom of the rigid hollow cuboid and the flexible joint are in the local coordinate system of the substructure. In order to realize the assembly of the whole structure, the present invention also needs to transform the rigid body degrees of freedom from the local coordinate system to the global coordinate system.

[0069] In the present invention, the first The interface degrees of freedom of the substructure are the connection point degrees of freedom , the motion of the connection point in the overall coordinate system of the machine tool (i.e., the motion trajectory information) is recorded as ,but The rigid body degrees of freedom of all low-order substructures in the series kinematic chain (the first k substructures selected in ascending order from the preset topological relationship number) Dependency, connection point degrees of freedom It can be written as: ; in, Indicates motion trajectory information Rigid body degrees of freedom The relationship matrix between them.

[0070] In one embodiment, taking the Y-axis as an example, the low-order structure of the Y-axis motion structure on the tool side motion chain is the base, so, for: ; in, , , They respectively represent the position coordinates of the center of mass of the Y-axis moving structure relative to the center of mass of the base at the initial position; , , They respectively represent the position coordinates of the rigid body mass center relative to the connection node in the Y-axis motion structural component substructure; Indicates the feed motion displacement of the Y axis.

[0071] On the basis of the above embodiment, the dynamic equation of the ultra-precision vertical five-axis machining center is constructed according to the target structure dynamic matrix and the connection point degrees of freedom, including: Based on the displacement coordination and force balance conditions, according to the connection relationship between the various structural parts, the various target dynamic matrices are connected through the connection matrix to obtain the connected target dynamic matrix; the various target mass matrices are connected through the connection matrix to obtain the connected target mass matrix; the various target stiffness matrices are connected through the connection matrix to obtain the connected target stiffness matrix; the various target damping matrices are connected through the connection matrix to obtain the connected target damping matrix; The dynamic equation of the ultra-precision vertical five-axis machining center is constructed according to the target dynamic matrix after connection, the target mass matrix after connection, the target stiffness matrix after connection, the target damping matrix after connection and the degree of freedom of the connection point; The method further comprises: The oil film joint portion between the guide rail and the slider is equivalent to a one-way spring damping unit, and a first stiffness value is obtained according to the one-way spring damping unit and historical test data; Equivalently treating the contact parts between the machine tool bed, the column and the crossbeam as a three-way spring unit, and obtaining a second stiffness value according to the three-way spring unit and the historical test data; Calculating a third stiffness value based on mass information of a machine tool component supported by the air-floating vibration isolation unit and a natural frequency of the air-floating vibration isolation unit; Equivalently converting the cross roller bearing between the machine tool cradle and the machine tool turntable into a six-way spring unit, and acquiring a fourth stiffness value according to the six-way spring unit and the historical test data; The topological structure parameters to be optimized of the machine tool to be optimized are constructed according to the mass information and the moment of inertia of the rigid hollow cuboid, and the first stiffness value, the second stiffness value, the third stiffness value, and the fourth stiffness value.

[0072] In the present invention, the connection matrix of the whole structure is constructed according to the displacement coordination and force balance conditions between the degrees of freedom. , and then connect the corresponding matrices through this connection matrix, as follows: ; ; ; The dynamic equation of the whole machine, that is, the dynamic equation of the ultra-precision vertical five-axis machining center, can be constructed through the above-mentioned related matrix after connection and the degree of freedom q of the connection point, which is specifically expressed as: .

[0073] In the present invention, for the machine tool to be optimized, there is usually a lubricating oil film between the guide rail and the slider in the machine tool to reduce friction and wear. In the dynamic simulation, in order to simplify the model, this oil film joint can be equivalent to a one-way spring damping unit. This unit has spring and damping characteristics only in one direction (usually the sliding direction of the guide rail), and can simulate the resistance and restoring force of the oil film on the movement of the slider. Furthermore, in order to obtain the first stiffness value of this one-way spring damping unit, historical test data can be used. These historical test data may include the motion response of the guide rail and the slider under different speeds and load conditions, such as displacement, velocity, acceleration, etc. By analyzing these data, the stiffness value of the equivalent spring, that is, the first stiffness value, can be calculated.

[0074] The contact parts between the bed, columns and beams of the machine tool are usually more complicated, involving interactions in multiple directions. In order to simplify the model, the present invention can equate these contact parts to three-way spring units. The three-way spring unit has spring characteristics in three orthogonal directions (usually X, Y, and Z directions), and can simulate the stiffness and damping of the contact parts in different directions. Similarly, in order to obtain the second stiffness value of this three-way spring unit, it is also necessary to use historical test data, including the overall deformation and vibration response of the machine tool under different working conditions. By analyzing these historical test data, the stiffness values ​​of the equivalent spring in each direction can be calculated, and the second stiffness value can be obtained comprehensively.

[0075] Some parts of the machine tool may be supported by air-floating vibration isolation units to reduce vibration and noise. In order to calculate the stiffness value (third stiffness value) of the air-floating vibration isolation unit, it is necessary to know the mass information of the component and the natural frequency of the air-floating vibration isolation unit. Among them, the natural frequency is the frequency of the air-floating vibration isolation unit during free vibration, which is related to the stiffness and mass of the unit. The natural frequency of the air-floating vibration isolation unit can be obtained by measuring or consulting relevant information. Then, using the mass information and natural frequency, the stiffness value of the air-floating vibration isolation unit, that is, the third stiffness value, can be calculated.

[0076] The cross roller bearing between the machine tool cradle and the machine tool turntable is a complex connection component involving interactions in multiple directions. In order to simplify the model, the present invention can equate this bearing to a six-way spring unit. This six-way spring unit has spring characteristics in six directions (three translation directions and three rotation directions), and can simulate the stiffness and damping of the bearing in different directions. In order to obtain the fourth stiffness value of this six-way spring unit, it is also necessary to use historical test data. These historical test data include the relative movement and deformation of the machine tool cradle and turntable under different working conditions. By analyzing these historical test data, the stiffness values ​​of the equivalent spring in each direction can be calculated, and the fourth stiffness value can be obtained comprehensively.

[0077] Figure 5 For the schematic diagram of the structural parts of the different direction axes provided by the present invention, please refer to Figure 5 As shown in the figure, in the machine tool coordinates, each structural part is equivalent to a rigid hollow cuboid, where the length of the rigid hollow cuboid equivalent to the i-th structural part along the X-axis direction is recorded as ,like Figure 5 As shown in (a) in the figure; the length along the Y axis is ,like Figure 5 (c) in the figure; the length along the Z axis is recorded as ,like Figure 5 As shown in (b) in .

[0078] Figure 6The schematic diagram of the equivalent hollow cuboid of the X-axis motion structural member provided by the present invention can be referred to Figure 6 As shown, the present invention takes the X-axis moving structural member equivalent hollow cuboid as an example to illustrate the idea of ​​selecting structural member optimization parameters. Specifically, the X-axis moves along the X direction. The length is the maximum value of the guaranteed stroke. , Take the minimum value to ensure the stiffness of the structural member ,when When it increases, the X-axis's ability to resist deformation around the X-axis increases, but the quality of the structural parts Increase, and then select As the X-axis quality-related parameter to be optimized, the span of the guide slider in the Y direction Also changed accordingly, specifically: ; in, Indicates the length of the structural member along the Y direction in the initial state Span with guide rail slider along Y direction ratio.

[0079] Similarly, choose As the quality-related parameter to be optimized in the Z axis, select As the parameters to be optimized related to the quality of the Y-axis, the quality information of each structural component is as follows: ; Therefore, the X-axis mass Is the length of the X-axis structural member along the Y direction Function of Z-axis mass Is the length of the Z-axis structural member along the X direction Function of Y-axis mass Is the length of the Y-axis structural member along the X direction function.

[0080] When optimizing the centroid position of the structural parts, the relative positions of the structural parts are kept unchanged. Figure 7 This is a schematic diagram of the relative positions of the various structural components provided by the present invention. For details, please refer to Figure 7 shown.

[0081] Figure 8 A schematic diagram of the structure of a hollow cuboid provided by the present invention can be referred to Figure 8 As shown, further, the calculation Figure 8 Coordinates of the center of mass of the hollow cuboid shown relative to the geometric center of the outer cuboid, where: The length, width, and height of the outer cuboid are: , , .

[0082] The length, width, and height of the inner cuboid are: , , .

[0083] The coordinates of the lower left corner of the bottom of the outer cuboid are: .

[0084] The coordinates of the lower left corner of the bottom of the inner cuboid are: .

[0085] The mass of the outer cuboid is: .

[0086] The mass of the inner cuboid is: .

[0087] Coordinates of the center of mass of the outer cuboid: ; Coordinates of the center of mass of the inner cuboid: ; The mass of the outer cuboid is: ; The mass of the inner cuboid is: ; The total mass of the hollow cuboid: ; Furthermore, the mass-weighted average method is used to calculate the centroid coordinates of the hollow cuboid: , which can be expressed as: ; Then we can get the coordinate offset of the center of mass of the hollow cuboid relative to the geometric center of the outer cuboid: ; Among them, the center of mass position coordinates Need to satisfy: .

[0088] In the present invention, for the moment of inertia of the uniform cuboid, the moment of inertia of the outer cuboid is: ; The moment of inertia of the inner cuboid is: ; According to the parallel axis theorem, the moment of inertia of the outer cuboid in the centroid coordinate system is: ; The moment of inertia of the inner cuboid in the mass center coordinate system: ; After the coordinates of the center of mass position change, the moment of inertia of the hollow cuboid is: .

[0089] In the present invention, the guide rail is a closed hydrostatic guide rail, so the oil film where the guide rail contacts the slider only bears normal force. The present invention treats the oil film joint as a one-way spring damping unit. Fig. 9 This is a schematic diagram of the structure of the one-way spring damping unit provided by the present invention. For details, please refer to Fig. 9 As shown, the calculated values ​​of the stiffness of the equivalent spring unit of each guide rail and slider joint (i.e., the first stiffness value) are shown in Table 1: Table 1 Calculated values ​​of equivalent one-way spring element stiffness

[0090] Furthermore, boundary conditions are set for the stiffness of the fixed joint between the bed and the column. Since the bed, the column and the crossbeam are all made of mineral materials, a three-way spring unit can be used for equivalent treatment at the contact part. In one embodiment, a total of 28 groups of springs are used. Fig.10 This is a schematic diagram of the structure of the three-way spring unit provided by the present invention. For details, please refer to Fig.10 As shown in Table 2, the stiffness value (i.e., the second stiffness value) of the equivalent three-way spring unit is as follows: Table 2 Calculated values ​​of equivalent single three-way spring element stiffness

[0091] Furthermore, the boundary conditions are set for the stiffness of the air-floating vibration isolation unit, and the stiffness value k of the air-floating vibration isolation unit is calculated by the following formula: ; in, is the natural frequency of the vibration isolation unit itself; is the overall mass of the components supported by the vibration isolation unit. The stiffness value of the air-floating vibration isolation unit (i.e., the third stiffness value) is shown in Table 3: Table 3 Stiffness values ​​of air-floating vibration isolation units

[0092] Furthermore, boundary conditions are set for the stiffness of the cradle and the turntable. In the present invention, the cradle and the turntable are fixed and constrained by cross roller bearings, and the cross roller bearings are equivalent to six-way spring units to constrain the freedom of the cradle and the turntable to translate along the X, Y, and Z axes and rotate around the X, Y, and Z axes. The stiffness value of the six-way spring unit (i.e., the fourth stiffness value) is shown in Table 4: Table 4 Calculated values ​​of equivalent six-way spring element stiffness

[0093] The mass information and moment of inertia of the rigid hollow cuboid of the machine tool obtained through the above embodiment, as well as the first stiffness value, the second stiffness value, the third stiffness value and the fourth stiffness value obtained, can be used to construct the topological structure parameters to be optimized of the machine tool to be optimized. These parameters describe the connection relationship and stiffness characteristics between the various components of the machine tool, and are the basis for machine tool structure optimization and dynamic simulation.

[0094] The topological structure parameter optimization system of the ultra-precision vertical five-axis machining center provided by the present invention is described below. The topological structure parameter optimization system of the ultra-precision vertical five-axis machining center described below and the topological structure parameter optimization method of the ultra-precision vertical five-axis machining center described above can be referenced to each other.

[0095] Fig.11 The schematic diagram of the topological structure parameter optimization system for the ultra-precision vertical five-axis machining center provided by the present invention is as follows: Fig.11 As shown, the present invention provides a topological structure parameter optimization system for an ultra-precision vertical five-axis machining center, comprising a first processing module 1101, a second processing module 1102, a structural dynamic matrix calculation module 1103, a third processing module 1104 and a dynamic simulation processing module 1105, wherein the first processing module 1101 is used to treat each structural member in the machine tool to be optimized as equivalent to a corresponding rigid hollow cuboid, and use the center of mass of the rigid hollow cuboid as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; the second processing module 1102 is used to construct a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structures in each of the structural members of the machine tool to be optimized based on the connection relationship between the sub-structures in the structural members, wherein the flexible The joint is a flexible connecting substructure with six degrees of freedom in space; the structural dynamic matrix calculation module 1103 is used to calculate the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized based on the Lagrange equation, according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; the third processing module 1104 is used to determine the connection point degrees of freedom between the substructures in each of the structural parts according to the series motion chain formed by the substructures in each of the structural parts; the dynamic simulation processing module 1105 is used to construct the dynamic equation of an ultra-precision vertical five-axis machining center according to the target structural dynamic matrix and the connection point degrees of freedom, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, perform dynamic simulation according to the optimized topological structure parameters of the machine tool to be optimized, and obtain the dynamic parameter optimization result corresponding to the machine tool to be optimized.

[0096] The topological structure parameter optimization system for an ultra-precision vertical five-axis machining center provided by the present invention establishes a whole-machine multi-rigid body dynamic model of an ultra-precision vertical five-axis machining center with a fixed beam structure, and uses the mass of structural parts, the center of mass position of structural parts, and the stiffness of the joint of the guide rail and slider as the topological structure parameters to be optimized of the machine tool, thereby optimizing the ultra-precision vertical five-axis machining center with a fixed beam structure, providing a guarantee for the successful development of high-performance machine tools, and enabling the ultra-precision vertical five-axis machining center to have higher machining accuracy.

[0097] The system provided in the embodiment of the present invention is used to execute the above-mentioned method embodiments. Please refer to the above-mentioned embodiments for the specific process and detailed contents, which will not be repeated here.

[0098] Fig.12 A schematic diagram of the structure of an electronic device provided by the present invention, such as Fig.12 As shown, the electronic device may include: a processor (Processor) 1201, a communication interface (Communications Interface) 1202, a memory (Memory) 1203 and a communication bus 1204, wherein the processor 1201, the communication interface 1202, and the memory 1203 communicate with each other through the communication bus 1204. The processor 1201 can call the logic instructions in the memory 1203 to execute the topological structure parameter optimization method of the ultra-precision vertical five-axis machining center, the method comprising: equating each structural member in the machine tool to be optimized to a corresponding rigid hollow cuboid, and taking the center of mass of the rigid hollow cuboid as the origin, constructing a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; based on the connection relationship between the sub-structural members in each of the structural members of the machine tool to be optimized, constructing a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joint between the sub-structural members in each of the structural members, wherein the flexible joint is a flexible joint with six degrees of freedom in space. connecting sub-structures; based on the Lagrange equation, according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix, calculating the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized; according to the serial motion chain formed by the sub-structures in each of the structural parts, determining the connection point degrees of freedom between the sub-structures in each of the structural parts; constructing the dynamic equation of an ultra-precision vertical five-axis machining center according to the target structural dynamic matrix and the connection point degrees of freedom, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, performing dynamic simulation according to the topological structure parameters to be optimized of the machine tool to be optimized, and obtaining the dynamic parameter optimization results corresponding to the machine tool to be optimized.

[0099] In addition, the logic instructions in the above-mentioned memory 1203 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the 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 several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk.

[0100] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the topological structure parameter optimization method of the ultra-precision vertical five-axis machining center provided by the above-mentioned methods, and the method includes: equating each structural member in the machine tool to be optimized to a corresponding rigid hollow cuboid, and taking the center of mass of the rigid hollow cuboid as the origin, constructing a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; based on the connection relationship between the sub-structural members in each of the structural members of the machine tool to be optimized, constructing the corresponding flexible joints between the sub-structural members in each of the structural members The mass matrix, stiffness matrix and damping matrix of the flexible joint are obtained, wherein the flexible joint is a flexible connection substructure with six degrees of freedom in space; based on the Lagrange equation, the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized is calculated according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; according to the series motion chain formed by the substructures in each of the structural parts, the degrees of freedom of the connection points between the substructures in each of the structural parts are determined; according to the target structural dynamic matrix and the degrees of freedom of the connection points, the dynamic equation of an ultra-precision vertical five-axis machining center is constructed, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, dynamic simulation is performed according to the topological structure parameters to be optimized of the machine tool to be optimized, and the optimization results of the dynamic parameters corresponding to the machine tool to be optimized are obtained.

[0101] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the topological structure parameter optimization method of the ultra-precision vertical five-axis machining center provided in the above-mentioned embodiments, the method comprising: equating each structural member in the machine tool to be optimized to a corresponding rigid hollow cuboid, and taking the center of mass of the rigid hollow cuboid as the origin, constructing a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; based on the connection relationship between the sub-structural members in each of the structural members of the machine tool to be optimized, constructing a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structural members in each of the structural members, wherein , the flexible joint is a flexible connection substructure with six degrees of freedom in space; based on the Lagrange equation, according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix, the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized is calculated; according to the series motion chain formed by the substructures in each of the structural parts, the connection point degrees of freedom between the substructures in each of the structural parts are determined; according to the target structural dynamic matrix and the connection point degrees of freedom, the dynamic equation of an ultra-precision vertical five-axis machining center is constructed, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, dynamic simulation is performed according to the topological structure parameters to be optimized of the machine tool to be optimized, and the dynamic parameter optimization result corresponding to the machine tool to be optimized is obtained.

[0102] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0103] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center, characterized in that: include: Each structural part in the machine tool to be optimized is equivalent to a corresponding rigid hollow cuboid, and the center of mass of the rigid hollow cuboid is used as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; Based on the connection relationship between the sub-structures in each of the structural parts of the machine tool to be optimized, a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structures in each of the structural parts are constructed, wherein the flexible joints are flexible connection sub-structures with six degrees of freedom in space; Based on the Lagrange equation, the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized is calculated according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; Determining the degrees of freedom of connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members; According to the target structure dynamic matrix and the connection point degrees of freedom, the dynamic equation of the ultra-precision vertical five-axis machining center is constructed, and based on the dynamic equation of the ultra-precision vertical five-axis machining center, dynamic simulation is performed according to the topological structure parameters to be optimized of the machine tool to be optimized, and the dynamic parameter optimization results corresponding to the machine tool to be optimized are obtained.

2. The topological structure parameter optimization method of the ultra-precision vertical five-axis machining center according to claim 1 is characterized in that: The method further comprises: According to the movement mode and structural component composition information of each of the structural components in the machine tool to be optimized, the sub-structural components in each of the structural components in the machine tool to be optimized are divided into fixed sub-structural components and feed shaft sub-structural components, wherein the fixed sub-structural components are sub-structural components in the machine tool to be optimized where no feed motion occurs; and the feed shaft sub-structural components include moving sub-structural components and feed transmission sub-structural components.

3. The topological structure parameter optimization method of the ultra-precision vertical five-axis machining center according to claim 1 or 2, characterized in that: The method of taking the center of mass of the rigid hollow cuboid as the origin and constructing a dynamic matrix corresponding to the rigid hollow cuboid comprises: Taking the center of mass of the rigid hollow cuboid as the origin, constructing a local coordinate system corresponding to the rigid hollow cuboid; Based on the local coordinate system, the dynamic matrix corresponding to the rigid hollow cuboid is constructed according to the mass information and moment of inertia of the rigid hollow cuboid, wherein the mass information is calculated based on the mass information of the solid outer cuboid and the mass information of the hollow inner cavity cuboid of the rigid hollow cuboid; and the moment of inertia is calculated based on the moment of inertia information of the solid outer cuboid and the moment of inertia information of the hollow inner cavity cuboid of the rigid hollow cuboid.

4. The method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center according to claim 3, characterized in that: The method of constructing a mass matrix, a stiffness matrix and a damping matrix corresponding to the flexible joints between the sub-structures in each of the structural parts of the machine tool to be optimized based on the connection relationship between the sub-structures in each of the structural parts includes: Determining the flexible joints between the sub-structures in each of the structural members of the machine tool to be optimized based on the connection relationship between the sub-structures in each of the structural members; The flexible joint is equivalent to a six-way flexible connection substructure, wherein the six-way flexible connection substructure is composed of a six-degree-of-freedom spring damping unit, a first connection node and a second connection node; the first connection node and the second connection node are massless nodes, and the mass matrix corresponding to the six-way flexible connection substructure is a 12th-order zero matrix; The stiffness matrix and the damping matrix are constructed based on the translational stiffness, rotational stiffness, translational damping and rotational damping corresponding to the six-degree-of-freedom spring-damper unit.

5. The method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center according to claim 4, characterized in that: The target structural dynamic matrix corresponding to each structural component of the machine tool to be optimized is calculated based on the Lagrange equation according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix, including: Obtaining the generalized coordinates corresponding to the flexible joint in a twelve-degree-of-freedom dynamic system; Based on the Lagrange equation, according to the deformation of the six-degree-of-freedom spring damping unit and the generalized coordinates, respectively calculate the target dynamic matrix corresponding to the dynamic matrix in the twelve-degree-of-freedom power system, the target mass matrix corresponding to the mass matrix in the twelve-degree-of-freedom power system, the target stiffness matrix corresponding to the stiffness matrix in the twelve-degree-of-freedom power system, and the target damping matrix corresponding to the damping matrix in the twelve-degree-of-freedom power system; The target structural dynamic matrix is ​​obtained according to the target dynamic matrix, the target mass matrix, the target stiffness matrix and the target damping matrix.

6. The method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center according to claim 5, characterized in that: Determining the degrees of freedom of connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members comprises: Acquire motion trajectory information of connection points between the sub-structures in the serial kinematic chain in the global coordinate system of the machine tool to be optimized; Based on the preset topological relationship sequence numbers of the sub-structures in the machine tool to be optimized, determining the target sub-structure and the rigid body degrees of freedom corresponding to the target sub-structure; wherein the target sub-structure is the first k sub-structures selected in ascending order based on the preset topological relationship sequence numbers; A relationship matrix between the rigid body degrees of freedom corresponding to the target sub-structure and the motion trajectory information is constructed, and the degrees of freedom of the connection points between the sub-structures in each of the structures are determined according to the rigid body degrees of freedom corresponding to the target sub-structure and the relationship matrix.

7. The method for optimizing topological structure parameters of an ultra-precision vertical five-axis machining center according to claim 6, characterized in that: The method of constructing the dynamic equation of the ultra-precision vertical five-axis machining center according to the target structure dynamic matrix and the connection point degrees of freedom includes: Based on the displacement coordination and force balance conditions, according to the connection relationship between the various structural parts, the various target dynamic matrices are connected through the connection matrix to obtain the connected target dynamic matrix; the various target mass matrices are connected through the connection matrix to obtain the connected target mass matrix; the various target stiffness matrices are connected through the connection matrix to obtain the connected target stiffness matrix; the various target damping matrices are connected through the connection matrix to obtain the connected target damping matrix; The dynamic equation of the ultra-precision vertical five-axis machining center is constructed according to the target dynamic matrix after connection, the target mass matrix after connection, the target stiffness matrix after connection, the target damping matrix after connection and the degree of freedom of the connection point; The method further comprises: The oil film joint portion between the guide rail and the slider is equivalent to a one-way spring damping unit, and a first stiffness value is obtained according to the one-way spring damping unit and historical test data; Equivalently treating the contact parts between the machine tool bed, the column and the crossbeam as a three-way spring unit, and obtaining a second stiffness value according to the three-way spring unit and the historical test data; Calculating a third stiffness value based on mass information of a machine tool component supported by the air-floating vibration isolation unit and a natural frequency of the air-floating vibration isolation unit; Equivalently converting the cross roller bearing between the machine tool cradle and the machine tool turntable into a six-way spring unit, and acquiring a fourth stiffness value according to the six-way spring unit and the historical test data; The topological structure parameters to be optimized of the machine tool to be optimized are constructed according to the mass information and the moment of inertia of the rigid hollow cuboid, and the first stiffness value, the second stiffness value, the third stiffness value, and the fourth stiffness value.

8. A topological structure parameter optimization system for an ultra-precision vertical five-axis machining center, characterized in that: include: The first processing module is used to convert each structural member in the machine tool to be optimized into a corresponding rigid hollow cuboid, and use the center of mass of the rigid hollow cuboid as the origin to construct a dynamic matrix corresponding to the rigid hollow cuboid, wherein the rigid hollow cuboid is a rigid hollow cuboid with six degrees of freedom in space; A second processing module is used to construct a mass matrix, a stiffness matrix and a damping matrix corresponding to a flexible joint between the substructures in each of the structural parts of the machine tool to be optimized based on the connection relationship between the substructures in each of the structural parts, wherein the flexible joint is a flexible connection substructure with six degrees of freedom in space; A structural dynamic matrix calculation module, used for calculating the target structural dynamic matrix corresponding to each of the structural parts of the machine tool to be optimized based on the Lagrange equation, according to the dynamic matrix, the mass matrix, the stiffness matrix and the damping matrix; A third processing module is used to determine the degree of freedom of the connection points between the sub-structures in each of the structural members according to the serial kinematic chains formed by the sub-structures in each of the structural members; A dynamics simulation processing module is used to construct a dynamics equation of an ultra-precision vertical five-axis machining center according to the target structure dynamic matrix and the connection point degrees of freedom, and based on the dynamics equation of the ultra-precision vertical five-axis machining center, perform dynamics simulation according to the topological structure parameters to be optimized of the machine tool to be optimized, so as to obtain the dynamics parameter optimization results corresponding to the machine tool to be optimized.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the method for optimizing the topological structure parameters of the ultra-precision vertical five-axis machining center as claimed in any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for optimizing the topological structure parameters of an ultra-precision vertical five-axis machining center as claimed in any one of claims 1 to 7 is implemented.

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