Axial vibration double-position non-contact detection device and prediction method for five-axis machine tool workbench

文档序号:18593 发布日期:2021-09-21 浏览:42次 中文

阅读说明:本技术 五轴机床工作台轴向振动双位非接触检测装置及预测方法 (Axial vibration double-position non-contact detection device and prediction method for five-axis machine tool workbench ) 是由 吴石 刘涛瑞 刘献礼 于 2021-07-29 设计创作,主要内容包括:本发明提出了五轴机床工作台轴向振动双位非接触检测装置及预测方法。解决了现有机床加工过程中工作台振动不易测量,影响生产效率和加工质量的问题。分析计算包括设定工作台几何参数和材料参、建立回转工作台轴向振动模型,并通过回转工作台振动模型推导出动力学方程各项系数从而得到转台动力学方程。检测装置包括激光位移传感器电涡流传感器和磁力台架,磁力台架底座有一个磁力开关可将磁力台架牢固的吸附在机床摆台侧壁该结构利于拆装,台架有三个关节用于调节传感器位置该结构确保了传感器测量的精度,台架头部有弹簧卡槽该结构即可以固定传感器,同时关节连接处装有隔振装置据有好的减震性能。激光位移传感器与电涡流传感器放置于回转工作台上方并于工作台保持一定间隙,且间隙不应大于5mm,它主要用于双转台五轴机床回转工作台轴向振动的检测。(The invention provides an axial vibration double-position non-contact detection device and a prediction method for a five-axis machine tool workbench. The problem of among the current lathe course of working table vibration difficult measurement, influence production efficiency and processingquality is solved. The analysis and calculation comprises the steps of setting the geometric parameters and material parameters of the working table, establishing an axial vibration model of the rotary working table, and deducing each coefficient of a kinetic equation through the vibration model of the rotary working table so as to obtain a rotary table kinetic equation. The detection device comprises a laser displacement sensor and an eddy current sensor and a magnetic force rack, a magnetic force switch is arranged on a base of the magnetic force rack, the magnetic force rack can be firmly adsorbed on the side wall of the machine tool swing table through the magnetic force switch, the structure is favorable for disassembly and assembly, the rack is provided with three joints for adjusting the position of the sensor, the structure ensures the measuring precision of the sensor, the head of the rack is provided with a spring clamping groove, the structure can fix the sensor, and meanwhile, the joint connection part is provided with a vibration isolation device which has good vibration isolation performance. The laser displacement sensor and the eddy current sensor are arranged above the rotary worktable, a certain gap is kept between the rotary worktable and the laser displacement sensor, the gap is not larger than 5mm, and the laser displacement sensor and the eddy current sensor are mainly used for detecting the axial vibration of the rotary worktable of the five-axis machine tool with double rotary tables.)

1. Five-axis machine tool workstation axial vibration dibit non-contact detection device, its characterized in that: the detection device is provided with a magnetic rack, a laser displacement sensor, an eddy current sensor and a data acquisition system, wherein a magnetic rack base in the detection device is adsorbed on the side surface of a swing table at the lower end of a rotary working table through magnetic force, the magnetic rack of the detection device is composed of three joints, and the three joints can rotate at a large angle; the head of the vibration detection device can be provided with a laser displacement sensor and an eddy current sensor, a measuring head of the laser displacement sensor is right opposite to the surface of the workbench, a measuring head of the eddy current sensor is right opposite to the surface of the workbench, and a measuring mechanism is connected with the data acquisition system through an acquisition line; the vibration of the workbench is the axial vibration of the rotary workbench, and the innovation of the invention is that: the vibration mode of the axial vibration of the workbench can be rapidly detected and predicted by combining the workbench vibration detection device with the workbench vibration model; the test bench frame adopts vibration isolation devices at joints, so that the vibration damping performance of the test bench frame is improved, and the structure is simple; the test bench is composed of three joints, has the capability of multi-degree-of-freedom adjustment, and can enable the sensor to reach an optimal test position; the magnetic base is arranged at the lower end of the test bench and is provided with the magnetic switch, and when the test is needed, the bench can be fixed on the machine tool only by screwing the magnetic switch, so that the test bench is convenient to assemble and disassemble, and the test efficiency is improved; the top end interface of the test bench can be provided with various sensors and has the capability of changing the interface of the converter, and the test device has the vibration reduction performance, the multi-degree-of-freedom adjustment performance, the magnetic adsorption performance and the variable sensor interface.

2. The rotary table vibration detection apparatus according to claim 1, characterized in that: vibration detection mechanism includes magnetic base, magnetic switch is equipped with to magnetic base lower extreme, magnetic base adsorbs swing table side along with swing table swing magnetic force rack and swing table follow-up in the rotary worktable below, magnetic base is equipped with the vibration isolation device with magnetic force rack joint department, plays the effect that improves magnetic force rack stability when swing table swing magnetic force rack follow-up.

3. The table vibration detecting apparatus as set forth in claim 1, wherein: the magnetic force rack of the vibration detection mechanism is composed of three joints and a magnetic base, the three joints of the magnetic force rack can rotate at a large angle, the rotation of each joint of the magnetic force rack is controlled by a dividing plate, and vibration isolation devices are arranged at the joints of each joint of the magnetic force rack to prevent the joints from generating vibration to influence the measurement precision during rotation.

4. The table vibration detecting apparatus as set forth in claim 1, wherein: the utility model discloses a magnetic force rack, including magnetic force rack head, measuring head, work platform distance, magnetic force rack head is equipped with spring card groove and is convenient for the installation and the dismantlement of all kinds of sensors, but the mountable laser displacement sensor and current vortex sensor of magnetic force rack under the head condition not changed, laser displacement sensor's measuring head is fixed on the magnetic force rack while the measuring head is towards rotary table position, is 5mm with the work platform distance, current vortex sensor's measuring head is fixed on the magnetic force rack while the measuring head is towards rotary table position, is less than 5mm with the work platform distance.

5. The vibration detecting apparatus of a rotary table according to any one of claims 1 to 4, wherein: (1) the vibration mode of the axial vibration of the workbench can be rapidly detected and predicted by combining the workbench vibration detection device with the workbench vibration model; (2) the test bench frame adopts vibration isolation devices at joints, so that the vibration damping performance of the test bench frame is improved, and the structure is simple; (3) the test bench is composed of three joints, has the capability of multi-degree-of-freedom adjustment, and can enable the sensor to reach an optimal test position; (4) the magnetic base is arranged at the lower end of the test bench and is provided with the magnetic switch, and when the test is needed, the bench can be fixed on the machine tool only by screwing the magnetic switch, so that the test bench is convenient to assemble and disassemble, and the test efficiency is improved; (5) the top end interface of the test bench frame can be provided with various sensors, the test bench has the capacity of a variable converter interface, and the rotary workbench testing device has the characteristics of simple structure, high detection efficiency and strong feasibility.

6. The vibration detecting apparatus and analyzing method for a rotary table according to any one of claims 1 to 4, wherein: (1) establishing an initialization module, setting geometrical parameters of the rotary table by establishing a working space of the rotary table, setting initialization parameters of a laser displacement sensor and an eddy current sensor, selecting signals acquired by different sensors for the rotary table at different rotating speeds, adopting the signals acquired by the laser displacement sensor when the rotating speed of the rotary table is more than or equal to 500r/min, adopting the signals acquired by the eddy current sensor when the rotating speed of the rotary table is less than 500r/min, (2) adopting a self-adaptive control sensor and rotary table spacing for a magnetic rack, adjusting the sensor and rotary table spacing in real time according to the accuracy of measured axial vibration, controlling the rotation of each dividing disc of the rack by establishing a dynamic model of the magnetic rack, a rack motion planning algorithm and designing an angular motion control algorithm of each joint of the rack, and (3) comparing and analyzing vibration signals actually detected by the sensors with vibration signals obtained by theoretical analysis in combination with theoretical analysis, when the difference between the actually measured axial vibration signal and the theoretical analysis is more than 10%, the magnetic force rack automatically adjusts and resamples the vibration signal, when the difference between the actually measured axial vibration signal and the theoretical analysis is less than 10%, the vibration signal is input into the rotary table vibration model, (4) the processed vibration signal is transmitted into the rotary table vibration model, the analysis detection data establishes the rotary table axial vibration mathematical model, the rotary table axial vibration model is corrected according to the detection system, the nonlinear dynamics model of the rotary table axial vibration is established, the multidimensional data are fused, the rotary table vibration model is rebuilt, the system vibration bifurcation diagram is obtained, and the innovation point is that: different sensors can be adopted for combined measurement when the rotating speed of the workbench is different; when the difference between the actually measured axial vibration amplitude and frequency and the theoretical value is more than 10%, the distance between the sensor and the workbench can be adjusted in a self-adaptive manner; and (4) checking the correctness of the theoretical value model of the axial vibration of the rotary table according to the experimental value, and performing various nonlinear analyses and position working condition prediction on the axial vibration of the system by multi-data fusion.

Technical Field

The invention relates to a double-position non-contact detection device and a prediction method for axial vibration of a five-axis machine tool workbench, and belongs to the field of vibration detection of rigid rotating structures.

Background

With the wide application of high-precision machine tools in the industrial field, the situation of the precision reduction of the processed workpiece caused by the axial vibration of the rotary worktable is endless. The rotary worktable belongs to a basic rotary mechanical structure in industrial application, such as a turbine, a circular saw, a gyroscope and the like, and along with the reduction of the thickness and the increase of the rotating speed of the rotary worktable, the use performance of the machine can be influenced or limited due to the axial vibration caused by the eccentricity of a mounting shaft or external disturbance, the axial vibration is increased, the processing precision is reduced, and the quality of the processing surface of a workpiece is influenced. Therefore, the requirement on the axial stability of the structure of the rotary table is more and more strict. However, for a rotating structure, the installation of a wired sensor becomes a difficult problem, and the implementation of non-contact measurement and online axial vibration characteristic analysis are key links for predicting the axial vibration of the rotary table.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides the rotary table axial vibration detection device which can realize quick and stable detection, analysis and prediction of the rotary table axial vibration.

The invention also aims to provide a rotary table axial vibration detection and analysis prediction method.

The purpose of the invention can be achieved by adopting the following technical scheme:

the axial vibration detection device of the rotary worktable comprises a sensor, a magnetic force rack and a data processing mechanism, wherein the worktable is parallel to a horizontal plane; the vibration sensor comprises a laser displacement sensor and an eddy current sensor, the measuring head of the laser displacement sensor is 5mm away from the surface of the workbench, the measuring head of the eddy current sensor is less than 5mm away from the surface of the workbench, and the measuring head of the eddy current sensor is connected with a data acquisition box and a computer through a data acquisition line.

Further, the rotary table lower extreme is supported by the swing rack, and the magnetic base of magnetic force rack adsorbs and follow-up along with the swing of swing rack with the swing rack side, magnetic base is equipped with magnetic switch and is used for the loading and unloading of magnetic force rack, magnetic force magnetic base and magnetic force rack joint are equipped with vibration isolator and make the axial vibration that the rack produced when swinging along with the swing rack can not influence the signal appearance interference that the sensor gathered.

Furthermore, the device also comprises a measuring head, wherein the measuring head is composed of a laser displacement sensor and an eddy current sensor, the sensor can be selected randomly according to needs, the measuring head is convenient to replace, and the sensor only needs to be pulled out from a spring clamping groove in the head of the magnetic rack during replacement.

Further, axial vibration detection mechanism includes eddy current sensor, laser displacement sensor, eddy current sensor and laser displacement sensor install on two benches (two positions), and the magnetic force rack adsorbs in two sides of workstation lower extreme swing table, and the magnetic force rack symmetry is placed.

Furthermore, the magnetic force rack of the axial vibration detection mechanism is composed of three joints and a magnetic force base, each joint can rotate at a large angle, vibration isolation devices are arranged at joints of the joints, vibration caused by the joints in the rotation process is prevented from being transmitted to the sensor, the measurement precision is prevented from being reduced, and the rotation of the joints is controlled by the index plate.

Furthermore, the axial vibration detection mechanism is characterized in that axial vibration signals are collected by a sensor and then transmitted to a data collection box through a data collection line, the axial vibration signals are subjected to signal conversion and filtering processing through the collection box, the collected box transmits the processed signals to a computer, collection software is installed in the computer, the collection software can be developed secondarily, a rotary worktable dynamics equation is obtained by establishing a rotary worktable dynamics model, the equation is written into a python language and is embedded into the data collection software, the software after secondary development can perform error compensation and fitting on the actually measured axial vibration signals, and prediction analysis can be performed on the software after secondary development of some working conditions which are difficult to measure.

Furthermore, laser displacement sensor and current vortex sensor pass through spherical groove installation to be fixed on the magnetic force rack, laser displacement sensor and current vortex sensor gauge head all face the workstation and keep perpendicular in the workstation, laser displacement sensor and rotary worktable distance are 5mm, and current vortex sensor and rotary worktable distance are less than 5 mm.

Furthermore, the measuring heads of the laser displacement sensor and the eddy current sensor face the surface of the workbench, and a sensing module, a power supply module and an acquisition module are arranged in the measuring heads.

The detection device is provided with a magnetic rack, a laser displacement sensor, an eddy current sensor and a data acquisition system, wherein a magnetic rack base in the detection device is adsorbed on the side surface of a swing table at the lower end of a rotary working table through magnetic force, the magnetic rack of the detection device is composed of three joints, and the three joints can rotate at a large angle; the head of the axial vibration detection device can be provided with a laser displacement sensor and an eddy current sensor, a measuring head of the laser displacement sensor is right opposite to the surface of the workbench, a measuring head of the eddy current sensor is right opposite to the surface of the workbench, and a measuring mechanism is connected with the data acquisition system through an acquisition line; the worktable vibration is axial vibration of the rotary worktable. The axial vibration detection device of the workbench is combined with the axial vibration model of the workbench, so that the vibration mode of the axial vibration of the workbench can be rapidly detected and predicted; the test bench frame adopts vibration isolation devices at joints, so that the vibration damping performance of the test bench frame is improved, and the structure is simple; the test bench is composed of three joints, has the capability of multi-degree-of-freedom adjustment, and can enable the sensor to reach an optimal test position; the magnetic base is arranged at the lower end of the test bench and is provided with the magnetic switch, and when the test is needed, the bench can be fixed on the machine tool only by screwing the magnetic switch, so that the test bench is convenient to assemble and disassemble, and the test efficiency is improved; the test bed rack top port is capable of mounting a variety of sensors, with the capability of a variable transducer interface. The testing device has vibration damping performance, multi-degree-of-freedom adjusting performance, magnetic adsorption performance and a variable sensor interface.

Has the advantages that:

the invention mainly relates to a double-position non-contact detection device and a prediction method for axial vibration of a five-axis machine tool workbench, and mainly aims at the axial vibration of the rotary workbench in the machining process of the five-axis machine tool.

The invention extracts the axial vibration displacement value of the rotary worktable through the acquisition device by the axial vibration double-position non-contact detection device and prediction of the five-axis machine tool worktable, establishes a rotary worktable dynamic model by using a plate shell theory to calculate the displacement value of the rotary worktable, calculates a stable domain through Lyapunov stability calculation, finally guides the rotary worktable to select reasonable output torque, and can compensate the axial vibration of the rotary worktable through a machine tool rotary worktable compensation system in real time according to an axial vibration displacement bifurcation diagram, thereby reducing the axial vibration amplitude of the rotary worktable, avoiding the resonance of the rotary worktable and improving the precision of a processed workpiece.

For a five-axis machine tool rotary worktable, the axial vibration of the surface of the worktable is detected by using a laser displacement sensor and an eddy current sensor, the detected data is processed by a plurality of systems, and then the axial vibration near condition of the rotary worktable is analyzed and predicted by a function equation compiled in a computer.

Drawings

Fig. 1 is a schematic structural diagram of an axial vibration double-position non-contact detection device of a five-axis machine tool workbench.

Fig. 2 is a schematic view of the working structure of the axial vibration detection device system of the five-axis machine tool rotary table.

FIG. 3 is a schematic view of a connection structure of the laser displacement sensor, the eddy current sensor and the rack according to the present invention.

FIG. 4 is a schematic view of the magnetic base of the stand according to the present invention.

FIG. 5 is a flow chart of vibration reduction control of the axial vibration detection rack of the rotary table of the five-axis machine tool

FIG. 6 is a flow chart of the axial vibration detection system of the rotary table of the five-axis machine tool.

FIG. 7 is an axial vibration detection analysis prediction chaos bifurcation diagram of a rotary table of a five-axis machine tool.

The system comprises a 1-five-axis machine tool, a 2-data acquisition box, a 3-computer, a 4-first joint dividing disc, a 5-second joint dividing disc, a 6-third joint dividing disc, a 7-magnetic base switch, an 8-laser displacement sensor, a 9-eddy current sensor, a 10-first joint adjusting rod, an 11-pre-tightening bolt, a 12-joint protection shell, a 13-rotating shaft, a 14-second joint adjusting rod, a 15-horizontal rotating shaft, a 16-magnetic base shell, a 17-magnetic base adsorption surface, an 18-detachable rack head detaching hole, a 19-spring, a 20-small iron ball and a 21-spherical clamping groove.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely explained below with reference to the drawings in the embodiments of the present invention.

The present embodiment is explained with reference to fig. 1 to 7:

the rotary working axial vibration detection device is arranged on the side surface of a swing table of a five-axis machine tool 1 and swings along with the swing of the swing table in the machining process of the five-axis machine tool, and comprises a laser displacement sensor 8, an electric eddy current sensor 9, a data acquisition box 2, a computer 3 and then an axial vibration signal are analyzed and predicted after the acquired signal is transmitted to the computer 3 through the data acquisition box 2, the laser displacement sensor 8 and the electric eddy current sensor 9 are connected with a magnetic force rack through a spherical clamping groove 21 at the top end of the magnetic force rack, a small iron ball 20 and a spring 19 are arranged in the spherical clamping groove 21, the magnetic force rack is respectively provided with three joints, a first joint dividing disc 4 is arranged on the first joint, the first joint dividing disc 4 rotates a first joint adjusting rod 10 to adjust the rotation of the first joint, the first joint adjusting rod 10 is connected with a second joint, a second joint dividing disc 5 is arranged on the second joint, the second joint dividing disc 5 rotates the second joint adjusting rod 14, the second joint adjusting rod 14 is connected with a third joint, the third joint is provided with a third joint dividing disc 6, a magnetic base is connected below the third joint dividing disc 6 and protected by a magnetic base shell 16, and the lower end of the magnetic base is connected with a magnetic switch 7 for controlling the assembly and disassembly of the magnetic bench. The magnetic force rack is assembled and disassembled, and the magnetic force base adsorption surface 17 is attached to the side surface of the swing table.

As shown in fig. 1, the embodiment provides a rotary worktable axial vibration detection device, the device is installed on the side surface of a swinging table of a double-platform five-axis machine tool 1, and is connected with a data acquisition box 2 and a computer 3 through a data acquisition line, the detection device comprises a laser displacement sensor and an eddy current sensor, the detection device is fixed on the swinging table through a magnetic force rack, a spring clamping groove is used for fixing the laser displacement sensor and the eddy current sensor, and three joints of the magnetic force rack can rotate simultaneously to adjust the relative distance between the laser displacement sensor and the eddy current sensor to the worktable.

As shown in fig. 2, the present embodiment provides a rotary table axial vibration detection device, which is divided into two groups, and the two groups are symmetrically arranged at two ends of a five-axis machine tool table. The laser displacement sensor 8 and the eddy current sensor 9 are connected with the data acquisition box 2, the acquired signals are transmitted to the computer 3 through the data acquisition box 2, then axial vibration signals are analyzed and predicted, the laser displacement sensor 8 and the eddy current sensor 9 are connected with the magnetic force rack through a spherical clamping groove 21 at the top end of the magnetic force rack, a small iron ball 20 and a spring 19 are arranged in the spherical clamping groove 21, the magnetic force rack is respectively provided with three joints, a first joint dividing disc 4 is arranged on the first joint, the first joint dividing disc 4 rotates a first joint adjusting rod 10 to adjust the rotation of the first joint, the first joint adjusting rod 10 is connected with a second joint, the second joint dividing disc 5 is arranged on the second joint, the second joint dividing disc 5 rotates a second joint adjusting rod 14, the second joint adjusting rod 14 is connected with a third joint, the third joint dividing disc 6 is arranged on the third joint, a magnetic force base is connected below the third joint dividing disc 6, the magnetic base is protected by a magnetic base shell 16, and the lower end of the magnetic base is connected with a magnetic switch 7 for controlling the assembly and disassembly of the magnetic rack. The magnetic force rack is assembled and disassembled, and the magnetic force base adsorption surface 17 is attached to the side surface of the swing table.

As shown in figure 3, the top ends of the laser displacement sensor and the eddy current sensor are respectively provided with a spherical clamping groove, the head part of the magnetic force rack is provided with a spring clamping groove, and a small iron ball 20 and a spring 19 are arranged in the spherical clamping groove 21 to fix the sensors in the clamping grooves. And the sizes of the clamping grooves of the laser displacement sensor 8 and the eddy current sensor 9 are the same, so that the laser displacement sensor and the eddy current sensor can be conveniently replaced on the same magnetic rack.

As shown in fig. 4, a magnetic base switch 7 is installed on the magnetic base at the lower end of the magnetic rack to facilitate the assembly and disassembly of the magnetic rack. The magnetic base adsorption surface 17 is attached to the side face of the swing table during testing, the magnetic base adsorption surface is concave for improving stability, the magnetic base is shifted to an ON gear, and the magnetic table frame is firmly adsorbed to the side face of the swing table and follows up along with the swing of the swing table.

As shown in fig. 5, the control method of the magnetic force gantry is a flowchart, a dynamic model of the magnetic force gantry is established, a gantry motion planning algorithm is established, an angular motion control algorithm of each joint of the gantry is designed, a gantry position and power hybrid control system is designed, each index plate of the gantry is controlled to rotate, and vibration reduction control is performed on the whole gantry.

As shown in fig. 6, the geometrical material parameters of the rotary table are set by the working space of the rotary table constructed by the initialization module, the laser displacement sensor and the eddy current sensor are constructed, when the rotating speed of the rotary table is more than 500r/min, the axial vibration frequency of the rotary table is tested by the laser displacement sensor, and when the rotating speed of the rotary table is less than 500r/min, the axial vibration frequency of the rotary table is tested by the eddy current sensor. And when the difference between the test result and the theoretical calculation result is less than 10%, the test result is output to the computer to obtain a displacement bifurcation diagram of the axial vibration of the turntable.

As shown in fig. 7, the axial vibration bifurcation diagram is obtained by data processing. As well as vibration displacement diagrams, phase plane trajectory diagrams, poincare cross-sectional diagrams. The vibration bifurcation diagram can analyze the possible unstable working area of the rotary table. Theoretical guidance is provided for controlling unstable areas in the machining process, and the machining precision of workpieces is improved.

Writing an axial vibration dynamics model of a five-axis machine tool in a computer for analyzing and predicting the axial vibration rule of a rotary worktable, and calculating the model;

the stress analysis of the rotary worktable of the machine tool is carried out by taking the circular worktable as a columnar body, and the turning moment T of the rotary worktable of the machine tool rotating along the X axis of the machine tool can be seen from figure 11Rotational moment T about the Z axis2And meanwhile, the pressure q of the workpiece to the workbench, which is constantly changed in the machining process, is applied.

The external force applied to the rotary worktable of the machine tool is coupled with the self-generated internal stress of the rotary worktable, the rotary worktable is split into infinite units based on the plate-shell theory, the stress analysis of the units is shown in figure 2, and the unit is subjected to NrRadial force, NθCircumferential force, MrRadial bending moment, MθCircumferential bending moment, QrThe radial shear force, q (x, t), is the unit load of the workpiece with mass m on the rotary table.

Establishing a balance equation of the workbench, wherein c is a damping coefficient, rho is the material density of the rotary workbench, h is the thickness of the rotary workbench, and the rotary workbench is subjected to inertia forceDamping forceElastic restoring forceThe sum of the load and the applied external load-q (x, t) are equal to reach an equilibrium state. The equation is written as:

according to the Von Karman displacement strain relation, establishing a circumferential displacement strain equation and a radial displacement strain equation of the circular workbench:

in solving the planar problem in terms of stress,a complementary equation containing a stress component is derived from the geometric and physical equations, and therefore a compatible equation of strain and displacement is established as the solution stress function NrThe complementary equation of (1). Obtaining a compatibility equation from a displacement strain equation:

in which the displacement w of the rotary table in the Z direction, the radial length r, the radial displacement u, epsilon of the tablerAnd εhAre the radial and circumferential strain components. Young's modulus E, is Poisson's ratio v.

The response of a current continuous system to nonlinear free vibration can be assumed to be a dynamic displacement of the system in the modal direction ofTherefore, the Galerkin displacement equation is used for integrating the space, the space-time function is reduced in dimension to obtain a time-related function, and the following steps can be obtained:

only a differential function of time is left after space is integrated through a Galerkin displacement equation, so that a kinetic equation of the rotary worktable for time derivation can be obtained:

where τ is ω t, c1、c2、c3、c4Are kinetic equation coefficients.

Establishing an initialization module, setting the geometric parameters of the rotary table by establishing a working space of the rotary table, establishing a laser displacement sensor and an eddy current sensor to set initialization parameters, selecting signals acquired by different sensors for the rotary table at different rotating speeds, adopting the signals acquired by the laser displacement sensor when the rotating speed of the rotary table is more than or equal to 500r/min, and adopting the signals acquired by the eddy current sensor when the rotating speed of the rotary table is less than 500 r/min. The distance between the sensor and the rotary table is adjusted in real time according to the accuracy of measured axial vibration, and the rotation of each dividing plate of the table frame is controlled by establishing a dynamic model of the magnetic table frame, a table frame motion planning algorithm and a design control algorithm of the angular motion of each joint of the table frame. And comparing and analyzing the vibration signal actually measured by the sensor with the vibration signal obtained by theoretical analysis by combining theoretical analysis, automatically adjusting the magnetic rack to resample the vibration signal when the difference between the actually measured axial vibration signal and the theoretical analysis is more than 10%, and inputting the vibration signal into the rotary table vibration model when the difference between the actually measured axial vibration signal and the theoretical analysis is less than 10%. And transmitting the processed vibration signal to a rotary table vibration model, analyzing detection data to establish a rotary table axial vibration mathematical model, correcting the rotary table axial vibration model according to a detection system, establishing a nonlinear dynamic model of the rotary table axial vibration, fusing multidimensional data, and reconstructing the rotary table vibration model to obtain a system vibration bifurcation diagram. The innovation point is that: different sensors can be adopted for combined measurement when the rotating speed of the workbench is different; when the difference between the actually measured axial vibration amplitude and frequency and the theoretical value is more than 10%, the distance between the sensor and the workbench can be adjusted in a self-adaptive manner; and (4) checking the correctness of the theoretical value model of the axial vibration of the rotary table according to the experimental value, and performing various nonlinear analyses and position working condition prediction on the axial vibration of the system by multi-data fusion. And (3) measuring the axial vibration value of the rotary worktable according to the detection device, obtaining a rotary worktable kinetic equation based on a shell theory and a Von Karman displacement equation, substituting the measured value into the kinetic equation, and obtaining a chaotic bifurcation diagram so as to predict the axial vibration displacement condition of the rotary worktable. The vibration bifurcation diagram of the workbench under different working conditions can be obtained through a nonlinear dynamical equation, and a vibration displacement diagram, a phase plane trajectory diagram and a Poincare section diagram at a certain point can be generated according to the vibration bifurcation diagram. The vibration bifurcation diagram can analyze the possible unstable working area of the rotary table. Theoretical guidance is provided for controlling unstable areas in the machining process, and the machining precision of workpieces is improved.

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