Quantitative description method and device for servo dynamic characteristic matching

Abstract

The application discloses a kind of servo dynamic characteristic matching quantitative description method and device, wherein, method includes: based on preset instruction trajectory, define servo dynamic characteristic matching error angle, based on preset time domain tracking error model definition servo dynamic characteristic matching eigenvalue, by servo dynamic characteristic matching error angle and servo dynamic characteristic matching eigenvalue Quantitative description servo dynamic characteristic matching degree, to obtain quantitative description result based on reflecting the influence of servo dynamic characteristic matching degree on trajectory profile error and the influence of the structural parameters of machine tool shaft system on servo dynamic characteristic matching error angle cosine value.The thus, in the related art, lack the specific mathematical description of servo dynamic characteristic matching degree, lead to difficult quantitative interpretation the mathematical relationship between each parameter in machine tool shaft system and servo dynamic characteristic matching degree, lead to technical problems such as unclear and low precision of evaluation and identification object.

Description

Technical Field

[0001] This application relates to the field of servo control technology for five-axis linkage machine tools, and in particular to a quantitative description method and apparatus for servo dynamic characteristic matching. Background Technology

[0002] The development of high-end manufacturing has led to increasingly higher requirements for the precision and efficiency of machining complex curved surfaces, resulting in a trend towards high-speed, high-precision, and multi-functional high-precision machine tools. Dynamic performance is a decisive factor in machine tool machining efficiency and precision, making its optimization crucial. The degree of servo dynamic characteristic matching is a vital component of the dynamic performance of multi-axis CNC machine tools. Optimizing the matching degree of machine tool servo dynamic characteristics offers advantages such as low optimization cost, simple optimization methods, and significant improvement in the machining precision of complex curved surfaces. Therefore, optimizing the matching degree of machine tool servo dynamic characteristics has become a key aspect of dynamic performance optimization for multi-axis CNC machine tools and is one of the most effective means of improving the machining precision of complex curved surfaces.

[0003] With the deepening research on the servo dynamic characteristics of multi-axis CNC machine tools, the relationship between various parameters in the machine tool servo control feed system and the degree of matching of servo dynamic characteristics has gradually become clear. Currently, related technologies can control the degree of servo dynamic characteristic matching by adjusting the proportional amplification coefficient of each axis position loop to explore the relationship between the degree of servo dynamic characteristic matching and machine tool machining accuracy. However, these technologies focus on the influence mechanism of the degree of servo dynamic characteristic matching on machine tool machining accuracy and the sensitivity of dynamic performance testing to the degree of servo dynamic characteristic matching, lacking a specific mathematical description of the degree of servo dynamic characteristic matching. This makes it difficult to quantitatively explain the mathematical relationship between various parameters in the machine tool axis system and the degree of servo dynamic characteristic matching, leading to problems such as unclear evaluation and identification objects and low accuracy, which need to be improved. Summary of the Invention

[0004] This application provides a quantitative description method and apparatus for servo dynamic characteristic matching, in order to solve the technical problems in related technologies, such as the lack of a specific mathematical description of the degree of servo dynamic characteristic matching, which makes it difficult to quantitatively explain the mathematical relationship between the parameters of the machine tool axis system and the degree of servo dynamic characteristic matching, resulting in unclear evaluation and identification objects and low accuracy.

[0005] The first aspect of this application provides a quantitative description method for servo dynamic characteristic matching, applied to a multi-axis linkage machine tool. The method includes the following steps: defining a servo dynamic characteristic matching error angle based on a preset command trajectory to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error; defining a servo dynamic characteristic matching feature value based on a preset time-domain tracking error model to reflect the influence of the machine tool axis system's structural parameters on the cosine value of the servo dynamic characteristic matching error angle; and quantitatively describing the degree of servo dynamic characteristic matching using the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature value, thereby obtaining a quantitative description result based on the reflection of the influence of the degree of servo dynamic characteristic matching on the trajectory contour error and the influence of the machine tool axis system's structural parameters on the cosine value of the servo dynamic characteristic matching error angle.

[0006] Optionally, in one embodiment of this application, defining the servo dynamic characteristic matching error angle based on the preset command trajectory includes: taking the command trajectory synthesized by the orthogonal motion of the machine tool end in two directions as a reference, and defining the angle between the tracking error and the trajectory tangent vector as the servo dynamic characteristic matching error angle, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0007] Optionally, in one embodiment of this application, the definition formula for the servo dynamic characteristic matching error angle is:

[0008]

[0009] Where the included angle θ is the tracking error vector ΔC u,t With tangent vector C′ u The angle between them, u is a parameter variable of the specified trajectory C(u), and t is any moment when the end of the machine tool moves along the command trajectory C(u).

[0010] Optionally, in one embodiment of this application, defining the servo dynamic characteristic matching feature value based on the preset time-domain tracking error model includes: establishing a tracking error model in the time domain of a single machine tool axis system based on a preset machine tool axis system model; substituting the tracking error model into the expression for the cosine value of the servo dynamic characteristic matching error angle, so as to define the expression reflecting the influence of the machine tool axis system structural parameters on the cosine value of the servo dynamic characteristic matching error angle as the servo dynamic characteristic matching feature value.

[0011] Optionally, in one embodiment of this application, the calculation formula for the servo dynamic characteristic matching feature value is:

[0012]

[0013] Where, ξ yx S is the eigenvalue for matching the servo dynamic characteristics of the x-axis to the y-axis.p (u,t) is the cosine value of the servo dynamic characteristic matching error angle, k 2 (u) is the ratio of the rate of change of the input command on the y-axis to the rate of change of the input command on the x-axis.

[0014] A second aspect of this application provides a quantitative description device for servo dynamic characteristic matching, applied to a multi-axis linkage machine tool. The device includes: a first definition module for defining a servo dynamic characteristic matching error angle based on a preset command trajectory to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error; a second definition module for defining servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model to reflect the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle; and a quantitative description module for quantitatively describing the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature values, thereby obtaining a quantitative description result based on the reflection of the influence of the degree of servo dynamic characteristic matching on the trajectory contour error and the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle.

[0015] Optionally, in one embodiment of this application, the first definition module includes: a definition unit, used to take the command trajectory synthesized by the orthogonal motion of the machine tool end in two directions as a reference, and define the angle between the tracking error and the trajectory tangent vector as the servo dynamic characteristic matching error angle, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0016] Optionally, in one embodiment of this application, the definition formula for the servo dynamic characteristic matching error angle is:

[0017]

[0018] Where the included angle θ is the tracking error vector ΔC u,t With tangent vector C′ u The angle between them, u is a parameter variable of the specified trajectory C(u), and t is any moment when the end of the machine tool moves along the command trajectory C(u).

[0019] Optionally, in one embodiment of this application, the second definition module includes: a modeling unit, used to establish a tracking error model of a single machine tool axis system in the time domain based on a preset machine tool axis system model; and a matching unit, used to substitute the tracking error model into the expression for the cosine value of the servo dynamic characteristic matching error angle, so as to define the expression reflecting the influence of the machine tool axis system structural parameters on the cosine value of the servo dynamic characteristic matching error angle as the servo dynamic characteristic matching feature value.

[0020] Optionally, in one embodiment of this application, the calculation formula for the servo dynamic characteristic matching feature value is:

[0021]

[0022] Where, ξ yx S is the eigenvalue for matching the servo dynamic characteristics of the x-axis to the y-axis. p (u,t) is the cosine value of the servo dynamic characteristic matching error angle, k 2 (u) is the ratio of the rate of change of the input command on the y-axis to the rate of change of the input command on the x-axis.

[0023] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the quantitative description method for servo dynamic characteristic matching as described in the above embodiments.

[0024] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for quantitative description of servo dynamic characteristic matching.

[0025] This application embodiment can define a servo dynamic characteristic matching error angle based on a preset command trajectory to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error, thereby quantitatively describing the influence of the degree of servo dynamic characteristic matching on machine tool accuracy. It also defines servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model to reflect the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle, thus quantitatively describing the relationship between the degree of servo dynamic characteristic matching and its various influencing factors. Furthermore, it can be applied to servo dynamic characteristic matching between translational axes, between rotational axes, and between translational and rotational axes. It unifies the mathematical representation form and provides a very concise expression, solving the problem of inconsistent descriptions of servo dynamic characteristic matching between various types of axes. Finally, it quantitatively describes the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature values, obtaining quantitative description results and clarifying the quality of the servo dynamic characteristic matching and the magnitude of its influence on machine tool dynamic accuracy. This solves the technical problems in related technologies, such as the lack of a specific mathematical description of the degree of matching of servo dynamic characteristics, which makes it difficult to quantitatively explain the mathematical relationship between the degree of matching of various parameters in the machine tool axis system and the degree of matching of servo dynamic characteristics, resulting in unclear evaluation and identification objects and low accuracy.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 This is a flowchart of a quantitative description method for servo dynamic characteristic matching provided according to an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the overall structure of an AC rotary table five-axis linkage CNC machine tool according to an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of a motor servo control system model according to an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of a translational shaft mechanical transmission system according to an embodiment of this application;

[0032] Figure 5 This is a block diagram of a translational shaft mechanical transmission system after Laplace transformation according to an embodiment of this application;

[0033] Figure 6 This is a schematic diagram of a rotating shaft mechanical transmission system according to an embodiment of this application;

[0034] Figure 7 This is a block diagram of a rotating shaft mechanical transmission system after Laplace transformation according to an embodiment of this application;

[0035] Figure 8 This is a schematic diagram of the servo dynamic characteristic matching error angle according to an embodiment of this application;

[0036] Figure 9 This is a schematic diagram illustrating a method for matching servo dynamic characteristics according to an embodiment of this application;

[0037] Figure 10 This is a schematic diagram of the contour error of a straight line trajectory with a slope of 0.5, based on a simplified simulation verification result using Simulink according to an embodiment of this application.

[0038] Figure 11 This is a schematic diagram of the contour error of a straight line trajectory with a slope of 1.5, based on a simplified simulation verification result using Simulink according to an embodiment of this application.

[0039] Figure 12 This is a schematic diagram illustrating the influence of servo dynamic characteristic matching feature values ​​on the servo dynamic characteristic matching error angle according to an embodiment of this application;

[0040] Figure 13This is a schematic diagram illustrating the influence of servo dynamic characteristic matching feature values ​​on the servo dynamic characteristic matching error angle according to another embodiment of this application;

[0041] Figure 14 This is a schematic diagram of a quantitative description device for servo dynamic characteristic matching provided in an embodiment of this application;

[0042] Figure 15 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0043] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0044] The following description, with reference to the accompanying drawings, describes a quantitative description method and apparatus for servo dynamic characteristic matching according to embodiments of this application. Addressing the aforementioned background art, which lacks a specific mathematical description of the degree of servo dynamic characteristic matching, leading to difficulties in quantitatively explaining the mathematical relationship between various parameters in a machine tool axis system and the degree of servo dynamic characteristic matching, resulting in unclear evaluation and identification objects and low accuracy, this application provides a quantitative description method for servo dynamic characteristic matching. In this method, a servo dynamic characteristic matching error angle can be defined based on a preset command trajectory to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error, thereby quantitatively describing the influence of the degree of servo dynamic characteristic matching on machine tool accuracy. Servo dynamic characteristic matching feature values ​​are defined based on a preset time-domain tracking error model to reflect the machine tool axis system... This study investigates the influence of structural parameters on the cosine value of the servo dynamic characteristic matching error angle, thereby quantitatively describing the relationship between the degree of servo dynamic characteristic matching and its various influencing factors. It can be applied to servo dynamic characteristic matching between translational axes, between rotary axes, and between translational and rotary axes. It unifies the mathematical representation and provides a concise expression, resolving inconsistencies in the description of servo dynamic characteristic matching across various axes. Furthermore, it quantitatively describes the degree of servo dynamic characteristic matching using the servo dynamic characteristic matching error angle and servo dynamic characteristic matching characteristic values, obtaining quantitative results and clarifying the quality of the servo dynamic characteristic matching and its impact on the dynamic accuracy of the machine tool. This addresses the technical problems in related technologies where the lack of a specific mathematical description of the degree of servo dynamic characteristic matching makes it difficult to quantitatively explain the mathematical relationship between various parameters in the machine tool axis system and the degree of servo dynamic characteristic matching, leading to unclear evaluation and identification objects and low accuracy.

[0045] Specifically, Figure 1This is a flowchart illustrating a quantitative description method for servo dynamic characteristic matching provided in an embodiment of this application.

[0046] like Figure 1 As shown, this quantitative description method for servo dynamic characteristic matching is applied to multi-axis linkage machine tools. The method includes the following steps:

[0047] In step S101, based on the preset command trajectory, a servo dynamic characteristic matching error angle is defined to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0048] It is understandable that servo dynamic characteristic matching refers to the synchronization and coordination of the movements of different machine tool axes under the control of the servo system during the multi-axis trajectory motion process of a five-axis CNC machine tool with orthogonal motion directions of each axis system. The machine tool axis system involved in the motion consists of two parts: a motor servo control system and a mechanical transmission system. Currently, there are various types of machine tool axis systems applied to multi-axis CNC machine tools, and the influencing factors on the degree of servo dynamic characteristic matching differ for different machine tool axis systems.

[0049] To quantitatively describe the degree of servo dynamic characteristic matching, embodiments of this application may first define a parameter to quantitatively describe the impact of the degree of servo dynamic characteristic matching on machine tool accuracy. Specifically, embodiments of this application may quantitatively describe the impact of the degree of servo dynamic characteristic matching on trajectory contour error based on the servo dynamic characteristic matching error angle of the machine tool's preset command trajectory.

[0050] Optionally, in one embodiment of this application, a servo dynamic characteristic matching error angle is defined based on a preset command trajectory, including: taking the command trajectory synthesized by the orthogonal motion of the machine tool end in two directions as a reference, and defining the angle between the tracking error and the trajectory tangent vector as the servo dynamic characteristic matching error angle, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0051] Specifically, in this embodiment, the command trajectory synthesized by the orthogonal motion of the end of the machine tool along two directions can be used as a reference. That is, with the preset command trajectory as a reference, the angle between the tracking error and the tangent vector of the trajectory curve at the target position, i.e. the trajectory tangent vector, is defined as the servo dynamic characteristic matching error angle, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0052] Optionally, in one embodiment of this application, the formula for defining the servo dynamic characteristic matching error angle is:

[0053]

[0054] Where the included angle θ is the tracking error vector ΔC u,t With tangent vector C′u The angle between them, u is a parameter variable of the specified trajectory C(u), and t is any moment when the end of the machine tool moves along the command trajectory C(u).

[0055] In some embodiments of this application, the tangent vector of the command trajectory curve at the target position can be set as C′. u =(x′(u),y′(u)), the tracking error vector ΔC u,t With tangent vector C′ u The included angle θ is defined as the servo dynamic characteristic matching error angle, and we have:

[0056]

[0057] Where θ is the tracking error vector ΔC u,t With tangent vector C′ u The angle between them, u is a parameter variable of the specified trajectory C(u), and t is any moment when the end of the machine tool moves along the command trajectory C(u).

[0058] In step S102, a servo dynamic characteristic matching feature value is defined based on a preset time-domain tracking error model to reflect the influence of the structural parameters of the machine tool axis system on the servo dynamic characteristic matching error angle cosine value.

[0059] Furthermore, embodiments of this application can also define servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model, thereby reflecting the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle, so as to further realize a quantitative description of the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching feature values ​​of the time-domain tracking error model.

[0060] The preset time-domain tracking error model can be a typical time-domain tracking error model, which will be described below.

[0061] Optionally, in one embodiment of this application, defining servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model includes: establishing a tracking error model for a single machine tool axis system in the time domain based on a preset machine tool axis system model; substituting the tracking error model into the expression for the cosine value of the servo dynamic characteristic matching error angle, so as to define the expression reflecting the influence of the machine tool axis system structural parameters on the cosine value of the servo dynamic characteristic matching error angle as the servo dynamic characteristic matching feature value.

[0062] In actual implementation, the embodiments of this application can establish a tracking error model of a single machine tool axis system in the time domain based on a typical machine tool axis system model, the transfer function between the input position command and the tracking error in the complex frequency domain, and when the machine tool input is regarded as a continuous step signal, it is transformed to the time domain through inverse pull transformation to obtain the time domain tracking error model. The time domain tracking error model is substituted into the expression of the cosine value of the servo dynamic characteristic matching error angle to obtain the mathematical definition of the servo dynamic characteristic matching feature value based on the time domain tracking error model.

[0063] Optionally, in one embodiment of this application, the formula for calculating the servo dynamic characteristic matching feature value is:

[0064]

[0065] Where, ξ yx S is the eigenvalue for matching the servo dynamic characteristics of the x-axis to the y-axis. p (u,t) is the cosine value of the servo dynamic characteristic matching error angle, k 2 (u) is the ratio of the rate of change of the input command on the y-axis to the rate of change of the input command on the x-axis.

[0066] Here, we will explain how to define the matching feature values ​​of servo dynamic characteristics using a preset time-domain tracking error model, such as a typical time-domain tracking error model.

[0067] Specifically, embodiments of this application can establish a tracking error model for a single machine tool axis system in the time domain based on a typical machine tool axis system model, and input position command X in the complex frequency domain. i The transfer function H(s) between E(s) and the tracking error E(s), simplified to its simplest fractional form, is:

[0068]

[0069] Where s is the parameter variable in the complex frequency domain, and G1(s) and G2(s) are respectively:

[0070]

[0071]

[0072] Among them, T ii Let T be the integral time constant of the current loop. iv J is the integral time constant of the velocity loop. e J1 is the equivalent rotational inertia of the motor and lead screw, J2 is the rotational inertia of the driven shaft, and L is the equivalent rotational inertia of the motor and lead screw. a For armature inductance, i h Here, i0 is the reduction ratio of the ball screw, i0 is the first-stage reduction ratio from the driving shaft to the driven shaft, and M is the reduction ratio. t D is the platform load mass, D2 is the driven shaft damping coefficient, Dt K is the load damping coefficient. pi K is the proportional gain coefficient of the current loop. pv K is the proportional gain coefficient of the velocity loop. e K is the back electromotive force constant of the motor. t R is the torque coefficient of the electric motor, K2 is the torsional stiffness coefficient of the driven shaft, and R is the torque coefficient of the electric motor. a This is the armature resistance.

[0073] When the machine tool input is considered as a continuous step signal, the embodiments of this application can be converted to the time domain using a reverse pull transform to obtain a time-domain tracking error model:

[0074]

[0075] Where e(t) is the tracking error in the time domain, L -1 (x) is the inverse pull transform function, s is the parameter variable in the complex frequency domain, t is any time, x is the input position command, and w(t) can be defined by the above formula.

[0076] Substituting the time-domain tracking error model into the expression for the cosine value of the servo dynamic characteristic matching error angle, and after simplification, the embodiment of this application yields:

[0077]

[0078] When τ is equal to w at the servo cycle y (τ) / w x The value of (τ) is defined as the servo dynamic characteristic matching feature value of the x-axis to the y-axis, denoted as ξ. yx After further simplification, we can obtain:

[0079]

[0080] Where, ξ yx S is the eigenvalue for matching the servo dynamic characteristics of the x-axis to the y-axis. p (u,t) is the cosine value of the servo dynamic characteristic matching error angle, k 2 (u) is the ratio of the rate of change of the input command on the y-axis to the rate of change of the input command on the x-axis.

[0081] In step S103, the degree of servo dynamic characteristic matching is quantitatively described by the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching characteristic value. The quantitative description result is obtained based on the influence of the degree of servo dynamic characteristic matching on the trajectory contour error and the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle.

[0082] As one possible implementation, embodiments of this application can quantitatively describe the degree of servo dynamic characteristic matching using the servo dynamic characteristic matching error angle and servo dynamic characteristic matching feature value. This quantitative description is based on the influence of the servo dynamic characteristic matching degree on the trajectory contour error and the influence of the machine tool axis system structural parameters on the cosine value of the servo dynamic characteristic matching error angle. Taking a five-axis machine tool as an example, when it is necessary to quantitatively describe the degree of servo dynamic characteristic matching of the machine tool, the four servo dynamic characteristic matching error angle cosine values ​​S, with the x-axis as the reference, are used. p,xy (u,τ),S p,xz (u,τ),S p,xa (u,τ),S p,xc (u,τ) quantitatively describes the impact of the degree of servo dynamic characteristic matching on the trajectory contour error under a certain command trajectory, and includes four servo dynamic characteristic matching feature values ​​ξ based on the x-axis. yx ,ξ zx ,ξ ax ,ξ cx This paper quantitatively describes the inherent attribute of the degree of servo dynamic characteristic matching between axes, which is determined by the structural parameters of the machine tool axis system. It describes the degree of servo dynamic characteristic matching from two aspects: the influence of the degree of servo dynamic characteristic matching and the formation principle. The description method is comprehensive and accurate. Moreover, the concept of the defined servo dynamic characteristic matching feature value can be applied to the servo dynamic characteristic matching between translational axes, between rotational axes, and between translational and rotational axes. It unifies the mathematical representation form and the expression is very concise, solving the problem of inconsistent description of servo dynamic characteristic matching between various types of axes.

[0083] Combination Figures 2 to 13 As shown, the working principle of the quantitative description method for servo dynamic characteristic matching of the present application is explained in detail with an embodiment.

[0084] It is understandable that servo dynamic characteristic matching refers to the synchronization and coordination of the different machine tool axes under the control of the servo system during the multi-axis trajectory motion of a five-axis CNC machine tool with orthogonal motion directions of each axis system. The machine tool axis system involved in the motion consists of two parts: a motor servo control system and a mechanical transmission system. Currently, various types of machine tool axis systems are applied to multi-axis CNC machine tools, and the influencing factors on the degree of servo dynamic characteristic matching differ for different machine tool axis systems. Therefore, this application embodiment can take a certain AC rotary table type five-axis CNC machine tool as an example, and the structural schematic diagram of the machine tool is shown below. Figure 2 As shown.

[0085] The motor servo control system in this machine tool axis system consists of a PMSM (permanent-magnet synchronous motor) and a classic PID (proportional, integral, and derivative) three-loop control, as shown in the specific structure below. Figure 3 As shown; the mechanical transmission system mainly uses lead screw and nut transmission or worm gear transmission, and the specific structure is as follows. Figures 4-7 As shown. The control mode of the machine tool axis system can be considered to be the most commonly used position command control mode.

[0086] Among them, K pp K is the position loop proportional gain coefficient. pv K is the proportional gain coefficient of the velocity loop. pi T is the proportional gain coefficient of the current loop. iv Let T be the integral time constant of the velocity loop. ii L is the integral time constant of the current loop. a R is the armature inductance. a K is the armature resistance. t K is the torque coefficient of the electric motor. e J is the back electromotive force constant of the motor. e This is the equivalent rotational inertia of the motor and the lead screw.

[0087] exist Figures 4-7 The physical meanings of the symbols in the diagram are as follows: J1 is the moment of inertia of the driving shaft, J2 is the moment of inertia of the driven shaft, and J... t T is the moment of inertia of the worm gear under load. m θ is the output torque of the motor. m T is the motor output angle, T2 is the driven torque of the driven shaft, and T h θ is the output torque transmitted from the driven shaft to the ball screw. h K2 is the output angle of the ball screw driven by the driven shaft, D2 is the torsional stiffness coefficient of the driven shaft, and M is the damping coefficient of the driven shaft. t For platform load quality, D t X is the load damping coefficient. t For the displacement output of the moving platform, f t Let i be the load resistance of the moving platform, and i be the reduction ratio of the first stage reduction gear from the drive shaft to the driven shaft. h For the ball screw reduction ratio, i is the number of reduction ratios for a single-start thread. h =2π / P h , where P h This refers to the pitch of the ball screw.

[0088] contrast Figure 5 and Figure 7It can be seen that the transfer function expressions of the mechanical transmission systems of the translational shaft and the rotational shaft are consistent. Therefore, this application embodiment is only described using the servo dynamic characteristic matching between translational shafts as an example. The conclusions of the servo dynamic characteristic matching between rotational shafts can be obtained by analogy and will not be repeated here.

[0089] Combination Figure 3 and Figure 5 The system block diagram can be used to obtain the complete system structure of the machine tool axis system for each axis of the five-axis linkage CNC machine tool.

[0090] First, embodiments of this application can propose a mathematical definition of the servo dynamic characteristic matching error angle between two different machine tool axis systems to specifically and quantitatively explain the concept of servo dynamic characteristic matching.

[0091] like Figure 8 As shown, in this embodiment of the application, the command trajectory curve C(u) synthesized by orthogonal motions along the X and Y directions can be assumed to be continuous and differentiable: x = x(u), y = y(u), u ∈ [0,1]. When the end effector of the machine tool moves along this trajectory, the tracking error vector of the end effector relative to the input target position C(u) at any time t is ΔC. u,t =(e x (t),e y (t)), the tangent vector of the command trajectory curve at the target position is C′. u =(x′(u),y′(u)). The tracking error vector ΔC u,t With tangent vector C′ u The included angle θ is defined as the servo dynamic characteristic matching error angle, and we have:

[0092]

[0093] The above equation gives the mathematical definition of the servo dynamic characteristic matching error angle θ, and the cosine value of θ is denoted as S. p When the interpolation distance within each servo cycle during machine tool movement is small, the trajectory normal profile error E(u) of the machine tool end relative to the target position at any given moment can be approximately calculated using the following formula:

[0094]

[0095] The above equation gives the mathematical relationship between the servo dynamic characteristic matching error angle θ and the trajectory normal profile error E(u). From this equation, it can be concluded that the servo dynamic characteristic error angle actually reflects the degree of influence of servo dynamic characteristic matching on the trajectory normal profile error. That is, when the tracking error is constant, the greater the mismatch in servo dynamic characteristics between the two machine tool axis systems, the larger the servo dynamic characteristic matching error angle θ, and the larger the trajectory normal profile error. It should be noted that in actual engineering applications, the tangent vector C′ of the command trajectory curve...u The direction is often not constant, therefore even if the servo dynamic characteristic matching state between the two machine tool axis systems remains unchanged, the servo dynamic characteristic matching error angle θ and the cosine value S p Its size is also constantly changing.

[0096] As shown in the aforementioned expression, the magnitude of the trajectory normal profile error E(u) depends on the magnitude of the tracking error and the degree of matching of the servo dynamic characteristics between the two machine tool axis systems. The worse the tracking performance of each machine tool axis, the larger the trajectory normal profile error; the more mismatched the servo dynamic characteristics between the two machine tool axis systems, the larger the trajectory normal profile error will be. In the process of optimizing machine tool dynamic performance, simply improving the machine tool tracking performance often leads to a greater mismatch in the servo dynamic characteristics between the two machine tool axis systems, resulting in an increase in the trajectory normal profile error. The conclusions drawn above are consistent with the prevailing view in the academic community, indirectly confirming that the defined servo dynamic characteristic matching error angle reasonably describes the influence of the degree of matching of the servo dynamic characteristics between the two machine tool axis systems on the trajectory normal profile error.

[0097] A mathematical model of the tracking error of the machine tool axis system in the time domain is established based on the established machine tool axis system model. The magnitude of the tracking error is determined by two inputs: the input position command and the external disturbance torque present at that time. In the actual machine tool operation process, the influence of the input position command on the tracking error is reflected in the contour error, while the influence of the disturbance torque (mainly composed of cutting force) on the tracking error is reflected in the surface roughness and waviness. Since this study focuses on the contour error, the influence of the disturbance torque is not considered when mathematically modeling the tracking error. From the machine tool axis system structure shown, the input position command X in the complex frequency domain can be obtained. i The transfer function H(s) between E(s) and the tracking error E(s), simplified to its simplest fractional form, is:

[0098]

[0099] Wherein, G1(s) and G2(s) are respectively:

[0100]

[0101]

[0102] Next, based on the minimum time interval servo cycle of the CNC machine tool position input command, the mathematical analytical expression of the tracking error in the time domain is analyzed using the delay theorem. Due to the existence of the servo cycle, the machine tool's position command input is discrete; however, this discrete input can be considered to have a zero-order hold characteristic, therefore, the machine tool's position command input can be regarded as a continuous step input. If x... i Treating (t) as a continuous step input, it can be written in the following form

[0103]

[0104] Among them, t i (i = 1, 2, 3, ..., n-2, n-1, n) represents the input time of the i-th position command of the machine tool, Δx i The increment of the position command input for each servo cycle of the machine tool.

[0105] From the delay theorem, we can obtain the expression for the tracking error E(s) in the complex frequency domain:

[0106]

[0107] Transforming to the time domain, we get:

[0108]

[0109] Thus, the above equation presents a mathematical model in the time domain for the tracking error of a machine tool axis affected by an input position command under position control mode, using a three-loop PID control system based on a P-PI-PI structure. For a machine tool axis system with two orthogonal motion directions: the x-axis and the y-axis, the tracking error e of the two axes can be obtained. x (t) and e y (t) are respectively:

[0110]

[0111]

[0112] Among them, w x (t)=L -1 [H x (s) / s]and w y (t)=L -1 [H y (s) / s].

[0113] Substituting the above time-domain tracking error model for the x-axis and y-axis into S p From the definition, we can obtain that when the end effector of the machine tool moves towards a point on the command trajectory curve C(u) at time t, S is... p The size of is related to t and u, and its expression is:

[0114]

[0115] S can be obtained p The first-order partial derivative expression of (u,t) with respect to q(t) is then obtained, and the second-order partial derivative expression is further derived:

[0116]

[0117]

[0118] From the partial derivative expression, we know that S = k(u) if and only if q(t) = k(u). p When (u,t) reaches its maximum value of 1, the trajectory normal profile error is zero. Therefore, focusing on the mathematical expression of q(t), expanding q(t) yields:

[0119]

[0120] Considering that five-axis CNC machine tools, as high-precision machining equipment, are generally equipped with high-precision position measurement systems, we can assume that the tracking error caused by the input in the first n-1 servo cycles is negligible in the nth servo cycle, the servo cycle is sufficiently small, and the interpolation distance in each servo cycle is sufficiently short. The specific mathematical expression of the above assumptions is as follows:

[0121]

[0122] tt n →0 + ,

[0123]

[0124] Under the conditions shown in the above equation, the expression for q(t) can be further simplified to:

[0125]

[0126] Let τ = tt n S can be obtained p The expression for (u,τ) is:

[0127]

[0128] When τ is equal to w at the servo cycle y (τ) / w x The value of (τ) is defined as the servo dynamic characteristic matching feature value of the x-axis to the y-axis, denoted as ξ. yx As can be seen from the above expression, the servo dynamic characteristic matching characteristic value ξ has the following two characteristics: First, its magnitude depends only on the values ​​of each parameter in the two machine tool axis systems, that is, this parameter reflects the degree of matching between the inherent servo dynamic characteristics of the two machine tool axis systems; Second, because the transfer function between the input position command and the tracking error in the machine tool axis system is usually a high-order fraction, the complete and accurate mathematical expression of ξ is often very complex. Therefore, reasonable simplification methods are essential for analyzing the relationship between ξ and the structural parameters of the machine tool axis system.

[0129] Figure 9The diagram illustrates the specific process of quantitatively describing the matching of servo dynamic characteristics between two axes using two parameters: error angle and eigenvalue. The servo dynamic characteristic matching eigenvalue is used to quantitatively describe the degree of matching between the servo dynamic characteristics of the two axes; the servo dynamic characteristic matching error angle is used to quantitatively describe the extent to which the trajectory normal profile error is affected by the degree of matching between the servo dynamic characteristics of the two axes when a given input command is received.

[0130] It should be noted that the method proposed in this application for quantitatively describing servo dynamic characteristic matching by using servo dynamic characteristic matching feature value ξ and dynamic characteristic matching error angle θ is not limited to five-axis linkage CNC machine tools, but is applicable to all multi-axis machine tools.

[0131] From the above conclusions, the cosine value S of the servo dynamic characteristic matching error angle θ can be determined. p The magnitude of (u,τ) is influenced by the |k(u)| of the command trajectory curve and the eigenvalue ξ of the servo dynamic characteristic matching between the two axes. When w x (τ)≠w y (τ) represents the servo dynamic characteristic matching feature value ξ of the x-axis relative to the y-axis. yx When S is not 1, p The magnitude of (u,τ) changes with the magnitude of |k(u)|. The corresponding physical meaning is that when the servo dynamic characteristics of the two axes differ, and if other error factors are not considered, when the machine tool executes the command trajectory, the sensitivity of different points on the command trajectory curve to |k(u)| varies, resulting in differences in the trajectory curve profile error. Analysis shows that if and only if w x (τ)=w y (τ) represents the servo dynamic characteristic matching feature value ξ of the x-axis relative to the y-axis. yx When S equals 1, p (u,τ)=1 holds true for any |k(u)|. Its corresponding physical meaning is that when the servo dynamic characteristics of the two axes are exactly the same, for any command trajectory curve, if the influence of other error factors is not considered, the trajectory profile error of the machine tool when executing the command trajectory is always zero.

[0132] Through such Figure 3 and Figures 4-7 The Simulink simulation model shown verifies the conclusions summarized in the above analysis. When the input command trajectories are straight lines with slopes of 0.5 and 1.5 respectively, i.e., |k(u)|=0.5 and |k(u)|=1.5, w is set... y (τ) / w x The magnitudes of (τ) are 0.5, 1, and 2, and the measured output motion trajectories are as follows. Figure 10 and Figure 11As shown in the simulation results, if and only if w y (τ) / w x When (τ)=1, the contour errors of both command trajectories are zero. This simulation result verifies the accuracy of the above conclusion and also indirectly verifies the correctness of the relationship between the servo dynamic characteristic error angle and the servo dynamic characteristic matching characteristic value obtained through approximation and simplification.

[0133] After completing the above simulation verification, ξ can be analyzed based on the relationship between the servo dynamic characteristic error angle and the servo dynamic characteristic matching characteristic value. yx For S p The influence of (u,τ) is as follows: Figure 12 and Figure 13 As shown. Figure 12 The following is given: S under linear command trajectories with different |k(u)|. p (u,τ) and ξ yx The relationship between them. As shown in the graph, when the value of |k(u)| of the straight-line command trajectory is too small, S... p (u,τ) for ξ yx The change is not sensitive, meaning that the change in the normal contour error of the command trajectory caused by the difference in the servo dynamic characteristics between the two axes is not significant; when the slope |k(u)| is near 1, S p (u,τ) for ξ yx The changes will be very sensitive; when |k(u)| is large, S p (u,τ) will only apply to ξ yx It is sensitive to variations within [0,1]. Figure 13 The following is given in ξ yx S takes different values p The relationship between (u,τ) and the value of |k(u)| at a point on the instruction trajectory curve C(u). Analysis shows that when |k(u)| is too large or too small, ξ... yx For S p The effect of (u,τ) will become very weak.

[0134] From the above analysis, it is easy to deduce that by comparing the command trajectory contour error E(u) generated by the machine tool moving under two different command trajectory curves of |k(u)|, it is possible to achieve the following for A. x (τ) / A y (τ) Preliminary identification of the magnitude. For example, when the machine tool moves along a command trajectory C1 with a slope k of 1, the normal profile error of the command trajectory curve is E1; when the machine tool moves along a command trajectory C2 with a slope k of 5, the normal profile error of the command trajectory curve is E2. If E1 > E2 and E2 ≈ 0, then ξ yx >1; If E1>E2 and E1>>0, E2>>0, then ξ yx <1.

[0135] Thus, the quantitative description of servo dynamic characteristic matching based on command trajectory and time-domain tracking error model has been completed, and the relationship between the two parameters defined for achieving quantitative description, namely the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching characteristic value, has been analyzed.

[0136] The quantitative description method for servo dynamic characteristic matching proposed in this application can define a servo dynamic characteristic matching error angle based on a preset command trajectory to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error, thereby quantitatively describing the influence of the degree of servo dynamic characteristic matching on machine tool accuracy. Based on a preset time-domain tracking error model, a servo dynamic characteristic matching feature value is defined to reflect the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle, thus quantitatively describing the relationship between the degree of servo dynamic characteristic matching and its various influencing factors. This method can be applied to servo dynamic characteristic matching between translational axes, between rotational axes, and between translational and rotational axes. It unifies the mathematical representation form and provides a very concise expression, solving the problem of inconsistent descriptions of servo dynamic characteristic matching between various types of axes. Furthermore, by quantitatively describing the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature value, a quantitative description result is obtained, clarifying the quality of the servo dynamic characteristic matching degree and the magnitude of its influence on the dynamic accuracy of the machine tool. This solves the technical problems in related technologies, such as the lack of a specific mathematical description of the degree of matching of servo dynamic characteristics, which makes it difficult to quantitatively explain the mathematical relationship between the degree of matching of various parameters in the machine tool axis system and the degree of matching of servo dynamic characteristics, resulting in unclear evaluation and identification objects and low accuracy.

[0137] Next, referring to the accompanying drawings, a quantitative description device for servo dynamic characteristic matching according to an embodiment of this application is described.

[0138] Figure 14 This is a block diagram of a quantitative description device for servo dynamic characteristic matching according to an embodiment of this application.

[0139] like Figure 14 As shown, the quantitative description device 10 for servo dynamic characteristic matching is applied to a multi-axis linkage machine tool, wherein the device 10 includes:

[0140] Specifically, the first definition module 100 is used to define the servo dynamic characteristic matching error angle based on the preset command trajectory, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0141] The second definition module 200 is used to define servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model, so as to reflect the influence of the structural parameters of the machine tool axis system on the servo dynamic characteristic matching error angle cosine value.

[0142] The quantitative description module 300 is used to quantitatively describe the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching characteristic value, so as to obtain the quantitative description result based on the influence of the degree of servo dynamic characteristic matching on the trajectory contour error and the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle.

[0143] Optionally, in one embodiment of this application, the first definition module 100 includes: a definition unit.

[0144] The definition unit is used to take the command trajectory synthesized by the orthogonal motion of the end of the machine tool along two directions as the reference, and the angle between the tracking error and the trajectory tangent vector is defined as the servo dynamic characteristic matching error angle to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error.

[0145] Optionally, in one embodiment of this application, the formula for defining the servo dynamic characteristic matching error angle is:

[0146]

[0147] Where the included angle θ is the tracking error vector ΔC u,t With tangent vector C′ u The angle between them, u is a parameter variable of the specified trajectory C(u), and t is any moment when the end of the machine tool moves along the command trajectory C(u).

[0148] Optionally, in one embodiment of this application, the second definition module 200 includes a modeling unit and a matching unit.

[0149] The modeling unit is used to establish a time-domain tracking error model for a single machine tool axis system based on a preset machine tool axis system model.

[0150] The matching unit is used to substitute the tracking error model into the expression for the cosine value of the servo dynamic characteristic matching error angle, so as to define the expression reflecting the influence of the machine tool axis system structural parameters on the cosine value of the servo dynamic characteristic matching error angle as the servo dynamic characteristic matching feature value.

[0151] Optionally, in one embodiment of this application, the formula for calculating the servo dynamic characteristic matching feature value is:

[0152]

[0153] Where, ξ yx S is the eigenvalue for matching the servo dynamic characteristics of the x-axis to the y-axis. p (u,t) is the cosine value of the servo dynamic characteristic matching error angle, k 2 (u) is the ratio of the rate of change of the input command on the y-axis to the rate of change of the input command on the x-axis.

[0154] It should be noted that the explanation of the aforementioned embodiment of the quantitative description method for servo dynamic characteristic matching also applies to the quantitative description device for servo dynamic characteristic matching in this embodiment, and will not be repeated here.

[0155] The quantitative description device for servo dynamic characteristic matching proposed in this application can define a servo dynamic characteristic matching error angle based on a preset command trajectory to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error, thereby quantitatively describing the influence of the degree of servo dynamic characteristic matching on machine tool accuracy. It also defines servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model to reflect the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle, thus quantitatively describing the relationship between the degree of servo dynamic characteristic matching and its various influencing factors. Furthermore, by quantitatively describing the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature values, a quantitative description result is obtained, clarifying the quality of the servo dynamic characteristic matching and the magnitude of its influence on the dynamic accuracy of the machine tool. This solves the technical problems in related technologies, such as the lack of a specific mathematical description of the degree of servo dynamic characteristic matching, which makes it difficult to quantitatively explain the mathematical relationship between various parameters in the machine tool axis system and the degree of servo dynamic characteristic matching, leading to unclear evaluation and identification objects and low accuracy.

[0156] Figure 15 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0157] The memory 1501, the processor 1502, and the computer program stored on the memory 1501 and executable on the processor 1502.

[0158] When the processor 1502 executes the program, it implements the quantitative description method of servo dynamic characteristic matching provided in the above embodiments.

[0159] Furthermore, electronic devices also include:

[0160] Communication interface 1503 is used for communication between memory 1501 and processor 1502.

[0161] The memory 1501 is used to store computer programs that can run on the processor 1502.

[0162] The memory 1501 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0163] If the memory 1501, processor 1502, and communication interface 1503 are implemented independently, then the communication interface 1503, memory 1501, and processor 1502 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 15 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0164] Optionally, in a specific implementation, if the memory 1501, processor 1502, and communication interface 1503 are integrated on a single chip, then the memory 1501, processor 1502, and communication interface 1503 can communicate with each other through an internal interface.

[0165] The processor 1502 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0166] This embodiment also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for quantitatively describing servo dynamic characteristic matching.

[0167] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0168] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0169] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0170] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0171] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0172] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0173] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0174] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for quantitatively describing servo dynamic characteristic matching, characterized by, Applied to multi-axis linkage machine tools, the method includes the following steps: Based on the preset command trajectory, a servo dynamic characteristic matching error angle is defined to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error. Based on a preset time-domain tracking error model, servo dynamic characteristic matching feature values ​​are defined to reflect the influence of the machine tool axis system's structural parameters on the servo dynamic characteristic matching error angle cosine value. The degree of servo dynamic characteristic matching is quantitatively described by the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature value. The quantitative description result is obtained based on the influence of the degree of servo dynamic characteristic matching on the trajectory contour error and the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle. The step of defining the servo dynamic characteristic matching error angle based on the preset command trajectory includes: taking the command trajectory synthesized by the orthogonal motion of the end of the machine tool along two directions as a reference, and defining the angle between the tracking error and the trajectory tangent vector as the servo dynamic characteristic matching error angle to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error. The step of defining servo dynamic characteristic matching feature value based on preset time-domain tracking error model includes: establishing a tracking error model of a single machine tool axis system in the time domain based on a preset machine tool axis system model; substituting the tracking error model into the expression of servo dynamic characteristic matching error angle cosine value, so as to define the expression reflecting the influence of machine tool axis system structural parameters on servo dynamic characteristic matching error angle cosine value as servo dynamic characteristic matching feature value; The formula for calculating the servo dynamic characteristic matching feature value is as follows: wherein, is a cosine value of a servo dynamic characteristic matching error angle, is a cosine value of a servo dynamic characteristic matching error angle, is a ratio of a y-axis input command change rate to an x-axis input command change rate.

2. The method according to claim 1, characterized in that, The formula for defining the servo dynamic characteristic matching error angle is: Among them, the included angle For tracking error vector tangent vector The angle between them u For the specified trajectory C( u The parameter variables of ) t For the end-effector of the machine tool, extend the command trajectory C( u Any moment during the movement.

3. A quantitative description device for servo dynamic characteristic matching, characterized in that, Applied to multi-axis linkage machine tools, wherein the device includes: The first definition module is used to define the servo dynamic characteristic matching error angle based on the preset command trajectory, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error. The second definition module is used to define servo dynamic characteristic matching feature values ​​based on a preset time-domain tracking error model, so as to reflect the influence of the structural parameters of the machine tool axis system on the servo dynamic characteristic matching error angle cosine value. The quantitative description module is used to quantitatively describe the degree of servo dynamic characteristic matching through the servo dynamic characteristic matching error angle and the servo dynamic characteristic matching feature value, so as to obtain the quantitative description result based on the influence of the degree of servo dynamic characteristic matching on the trajectory contour error and the influence of the structural parameters of the machine tool axis system on the cosine value of the servo dynamic characteristic matching error angle. The first definition module includes a definition unit, which uses the command trajectory synthesized by the orthogonal motion of the end of the machine tool along two directions as a reference, and defines the angle between the tracking error and the trajectory tangent vector as the servo dynamic characteristic matching error angle, so as to reflect the influence of the degree of servo dynamic characteristic matching on the trajectory contour error. The second definition module includes: a modeling unit, used to establish a tracking error model of a single machine tool axis system in the time domain based on a preset machine tool axis system model; and a matching unit, used to substitute the tracking error model into the expression for the cosine value of the servo dynamic characteristic matching error angle, so as to define the expression reflecting the influence of the machine tool axis system structural parameters on the cosine value of the servo dynamic characteristic matching error angle as the servo dynamic characteristic matching feature value. The formula for calculating the servo dynamic characteristic matching feature value is as follows: in, The characteristic values ​​are used to match the servo dynamic characteristics of the x-axis to the y-axis. To match the cosine value of the error angle for servo dynamic characteristics, This is the ratio of the rate of change of the input command on the y-axis to the rate of change of the input command on the x-axis.

4. The apparatus according to claim 3, characterized in that, The formula for defining the servo dynamic characteristic matching error angle is: Among them, the included angle For tracking error vector tangent vector The angle between them u For the specified trajectory C( u The parameter variables of ) t For the end-effector of the machine tool, extend the command trajectory C( u Any moment during the movement.

5. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the quantitative description method for servo dynamic characteristic matching as described in claim 1 or 2.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the quantitative description method of servo dynamic characteristic matching as described in claim 1 or 2.

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