A linear guide precision detection device based on a planar motor

Abstract

This invention discloses a linear guide rail accuracy testing device based on a planar motor, mainly composed of a probe, a spherical universal joint, a mounting bracket, a planar motor, and a data processing device. It enables high-precision measurement of the straightness, parallelism, and surface microstructure of linear guide rails. The invention uses a planar motor as the driving device, driving the probe to perform two-degree-of-freedom translation and deflection within the test plane, eliminating the influence of vibration and friction wear on the test data. By controlling the probe's pose change, the influence of installation errors on the test results is reduced, and the surface information of the guide rail is accurately acquired. The data processing device performs splicing and fitting calculations on the test data to complete the guide rail accuracy measurement. This invention has the advantages of strong anti-interference ability and high support stiffness, and is particularly suitable for measurement scenarios such as high-precision linear guide rails and ultra-long guide rails.

Description

Technical Field

[0001] This invention relates to the field of high-precision CNC machine tool guide rail accuracy measurement, and in particular to a linear guide rail accuracy detection device based on a planar motor. Background Technology

[0002] Precision CNC machine tools are widely used in precision manufacturing fields such as aviation, aerospace, and vehicle engineering, and their machining accuracy directly determines the level of a country's manufacturing industry. Linear guides, as key functional components of machine tools, are subject to external loads and temperature changes during machining, resulting in slight deformations, geometric errors, and reduced machine tool accuracy. Error compensation methods focusing on geometric errors are an effective means of improving machine tool machining accuracy. Software is used to cancel out the original geometric errors of the machine tool, thus correcting the errors. Accurate error measurement is a prerequisite for error compensation. Currently, the method of measuring machine tool errors using machine tool interferometers, interferometers, and plane mirror groups is commonly used. By placing the mirror group on the machine bed and using the CNC system to control the feed of the motion platform, the geometric error value of the guide rail can be directly obtained. However, this method requires the use of multiple instruments, increasing equipment installation errors. Furthermore, factors such as vibration and friction wear during machine tool operation reduce the accuracy of error detection. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a linear guide rail accuracy detection device based on a planar motor. This device eliminates the influence of friction, wear and vibration on the detection results and has the advantages of simple operation, strong anti-interference ability and high support stiffness. It is particularly suitable for high-precision, large-range linear guide rail error measurement.

[0004] The technical solution of this invention is: a linear guide accuracy testing device based on a planar motor, characterized in that it mainly consists of a probe, a spherical universal joint, a dial indicator frame, a planar motor, and a data processing device. The guide system, as the application object of the testing device, mainly includes a machine tool bed, a linear guide, and bolts. The probe is located at the upper end of the linear guide and connected to the spherical universal joint, ensuring perpendicular contact with the measured plane of the linear guide. The spherical universal joint is fixedly mounted on the dial indicator frame, which is located at the axial upper end of the planar motor and connected by magnetic attraction. The planar motor is located on the radial side of the machine tool bed and the linear guide, arranged in parallel. The data processing device is connected to the probe and analyzes and processes the data acquisition results.

[0005] The spherical universal joint can achieve 135° arbitrary angle deflection in the three spatial coordinate directions, and can complete the precision measurement of the top, end and side surfaces of the linear guide rail; the dial indicator frame adopts a telescopic hollow structure with embedded displacement sensors, which can acquire the position information of the dial indicator frame in real time; the data processing device uses a splicing algorithm to process data, and can complete the precision measurement of ultra-long linear guide rails.

[0006] The principle of the above scheme is as follows: This invention proposes a linear guide accuracy detection device based on a planar motor, which can realize the measurement of straightness error, parallelism error, and surface micro-morphology of a large-range linear guide. First, the planar motor is installed on one side of the machine tool bed, ensuring parallel installation. The dial indicator holder is fixed to the top of the planar motor's mover via magnetic attraction, and a spherical universal joint is vertically clamped to the end of the dial indicator holder's crossbeam, allowing the probe to rotate at any angle within 135° in the three spatial coordinate directions. The dial indicator holder adopts a telescopic structure with a hollow internal structure and embedded laser displacement sensor, which measures the position information of the dial indicator holder's column and crossbeam, and transmits the data to the planar motor controller. By adjusting the magnitude and direction of the winding current, the planar motor is controlled to generate a two-degree-of-freedom yaw, achieving probe pose control. Through the linkage of the planar motor and the dial indicator holder, the probe is ensured to be in contact with the linear guide plane. The planar motor drives the probe to complete radial two-degree-of-freedom translation, realizing the acquisition of linear guide straightness, surface morphology information, and parallelism data. The data processing device analyzes and calculates the information to complete the linear guide accuracy measurement. Meanwhile, the data processing device also has a built-in data stitching algorithm, which can realize high-precision measurement of ultra-long linear guide rails.

[0007] The advantages of this invention compared to existing technologies are as follows: This invention is a linear guide rail accuracy testing device based on a planar motor, which, compared to the laser interferometer measurement method, eliminates the influence of vibration and friction wear on measurement accuracy during the measurement process. By introducing magnetic levitation technology into the field of guide rail accuracy measurement and utilizing a planar motor to achieve probe posture control, the influence of installation errors on measurement results is reduced, thus improving measurement accuracy. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the technical solution structure of the present invention;

[0009] Figure 2 This is a partial sectional view of the spherical universal joint, which is the technical solution of this invention.

[0010] Figure 3 This is a diagram of the table frame component of the technical solution of the present invention;

[0011] Figure 4 This is a schematic diagram of a planar motor assembly, representing the technical solution of this invention.

[0012] Figure 5 This is a scenario diagram illustrating the accuracy measurement of linear guideways using the technical solution of this invention. Detailed Implementation

[0013] like Figure 1The diagram shows the structural principle of the technical solution of this invention, a linear guide accuracy testing device based on a planar motor. Its main features include a probe 4, a spherical universal joint 5, a dial indicator 6, a planar motor 7, and a data processing device 8. The guide system, as the application object of the testing device, mainly includes a machine tool bed 1, a linear guide, and bolts 3 (A, B, C, D). The probe 4 is located at the upper end of the linear guide 2 and connected to the spherical universal joint 5, ensuring perpendicular contact with the measured plane of the linear guide 2. The spherical universal joint 5 is fixedly mounted on the dial indicator 6, which is located at the axial upper end of the planar motor 7 and connected magnetically. The planar motor 7 is located on one radial side of the machine tool bed 1 and the linear guide 2, arranged in parallel. The data processing device 8 is connected to the probe 4 and analyzes and processes the data acquisition results.

[0014] like Figure 2 The figure shows a partial cross-sectional view of the spherical universal joint of the present invention. The spherical universal joint assembly consists of a clamping shaft 501, a spherical shell 502, and a rotating column 503. The clamping shaft 501 is vertically clamped on the instrument frame assembly and has no spatial degree of freedom of movement. The spherical shell 502 is fixed on the clamping shaft 501 and serves as a protective element. It has four circular holes along the direction of the clamping shaft 501 and the circumferential direction for mounting the probe 4. The rotating column 503 is installed on the upper end of the clamping shaft 501 and inside the spherical shell. Its end is connected to the probe 4 and can rotate within 145° of three degrees of freedom in space. It can be used to measure the micro-morphology, straightness error, and parallelism error of the guide rail end face and side surface. It can also be used for the accuracy measurement of flat bed and slant bed guide rails.

[0015] like Figure 3 The diagram shows the meter frame assembly of the technical solution of this invention. The meter frame 6 adopts a detachable structure and mainly includes a base 601, a column 602, a column sensor 603, a crossbeam 604, and a crossbeam sensor 605. The base 601 is located at the bottom and plays a role in stable fixation. The column 602 is installed on the upper axial end of the base 601 by threads and adopts a hollow structure. The column sensor 603 is embedded in the column 602. The crossbeam 604 adopts a hollow structure and is installed vertically on the column 602 by threads. The crossbeam sensor 605 is embedded in the crossbeam 604. The column 602 and the crossbeam 604 both adopt a splicing structure and have a telescopic function, which is suitable for different scenarios. The column sensor 603 and the crossbeam sensor 605 respectively detect the spatial position information of the center of the column and the crossbeam, and transmit the detected data to the planar motor controller. The controller outputs the corresponding current to the corresponding winding to generate precise angle compensation.

[0016] like Figure 4The diagram shown illustrates the planar motor assembly of the present invention. The planar motor assembly mainly includes: an axial stator guide rail 701, an axial mover 702, windings, a protective device, a front radial stator 705, a rear radial stator 706, and a radial mover 707. The stator guide rail 701 is located at the lower axial end of the axial mover 702, windings, counterweight device, front radial stator 705, rear radial stator 706, and radial mover 707. The axial mover 702 is located at the upper axial end of the stator guide rail 701. The left front winding 703A, right front winding 703B, right rear winding, and left rear winding are fixedly connected below the axial mover 702 and to the stator guide rail 707. There is a 0.5mm gap between 01. The left front protective device 704A, right front protective device 704B, right rear protective device 704C, and left rear protective device are located radially outside the left front winding 703A, right front winding 703B, right rear winding, and right rear winding. The front radial stator 705 is fixed to the axial upper end of the axial mover 702. The rear radial stator 706 is located at the axial rear end of the front radial stator 705. The radial mover 707 is located axially above the axial mover 702, the front radial stator 705, and the rear radial stator 706, and there is a 0.5mm gap between it and the front radial stator 705 and the rear radial stator 706.

[0017] like Figure 5 The diagram shows a scenario for measuring the accuracy of linear guides using the technical solution of this invention. It can be used to measure the straightness, surface micro-morphology, and parallelism of linear guides. Taking the accuracy detection process of the guide rail end face as an example, the probe 4 is driven by the planar motor 7 to move along the left linear guide 2 (A) from point a to point b, completing the straightness and surface micro-morphology measurements. Based on the straightness measurement data, the planar motor 7 and the crossbeam of the gauge frame 6 are controlled to extend and retract, moving the probe 4 from point a of the left linear guide 2 (A) to point c of the right linear guide 2 (B). The straightness measurement action is repeated, and the two sets of data are analyzed to complete the parallelism measurement.

[0018] The stitching algorithm integrated in the data processing device 8 is mainly the ICP (Iterative Closest Point) algorithm, also known as the nearest neighbor iteration algorithm, which records the location information of the previous measurement data point as M. i The next measurement data point is denoted as N. j By rotating the vector R(θ0, θ) x θ y θ z Translation vector T(q) x q y q z The motion description is performed, and the specific calculation steps are as follows:

[0019] First, initialize the coordinates, with the rotation vector and translation vector being R(0) and T(0) respectively.

[0020] Secondly, regarding the last data segment M{m i The nearest distance m between N data points is calculated using the formula | i=1,2,L,Np}. i (k) If the two data segments can correspond, the quaternion method is used to solve the problem, and the convergence of the calculation results is judged.

[0021] Finally, the optimal R and T are obtained, and the measurement data splicing is completed.

[0022] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A linear guide rail accuracy testing device based on a planar motor, wherein the guide rail system is the object of application of the testing device, including a machine tool bed (1), a linear guide rail, and bolts; characterized in that, The detection device consists of a probe (4), a spherical universal joint (5), a dial indicator (6), a planar motor (7), and a data processing device (8). The probe (4) is located at the upper end of the linear guide and is connected to the spherical universal joint (5) to ensure that it maintains perpendicular contact with the plane being measured on the linear guide. The spherical universal joint (5) is fixedly installed on the dial indicator (6), which is located at the upper axial end of the planar motor (7) and is connected by magnetic attraction. The planar motor (7) is located on the radial side of the machine tool bed (1) and the linear guide, arranged in parallel. The data processing device (8) is connected to the probe (4) and analyzes and processes the data acquisition results. The frame adopts a detachable structure, including a base, column, column sensor, crossbeam, and crossbeam sensor. The base is located at the bottom and serves to stabilize and fix the structure. The column is installed on the upper axial end of the base by threads and has a hollow structure. The column sensor is embedded in the column. The crossbeam has a hollow structure and is installed vertically on the column by threads. The crossbeam sensor is embedded in the crossbeam. Both the column and the crossbeam adopt a splicing structure. The column sensor and the crossbeam sensor respectively detect the spatial position information of the center of the column and the crossbeam and transmit the detected data to the planar motor controller. The controller outputs the corresponding current to the corresponding winding to generate precise angle compensation.

2. The linear guide accuracy detection device based on a planar motor according to claim 1, characterized in that: The spherical universal joint (5) can achieve arbitrary angle deflection of 135° in the three spatial coordinate directions, and complete the precision measurement of the top, end and side surfaces of the linear guide rail.

3. The linear guide accuracy detection device based on a planar motor according to claim 1, characterized in that: The aforementioned table frame (6) adopts a retractable hollow structure with an embedded displacement sensor to obtain the table frame position information in real time.

4. The linear guide accuracy detection device based on a planar motor according to claim 1, characterized in that: The data processing device (8) uses a splicing algorithm to process data and complete the precision measurement of ultra-long linear guide rails.

5. The linear guide accuracy detection device based on a planar motor according to claim 1, characterized in that: The stitching algorithm integrated in the data processing device is the ICP algorithm, also known as the nearest neighbor iterative algorithm, which records the location information of the previous measurement data points as M. i The next measurement data point is denoted as N. j By rotating the vector R(θ0, θ) x θ y θ z Translation vector T(q) x q y q z The motion description is performed, and the specific calculation steps are as follows: First, initialize the coordinates, with the rotation vector and translation vector being R(0) and T(0) respectively; Secondly, regarding the last data segment M{m i The nearest distance m between N data points is calculated using the formula | i=1,2,L,Np}. i (k), if the two data segments correspond, use the quaternion method to solve the problem and judge the convergence of the calculation results; Once the optimal R and T are obtained, the measurement data splicing is completed.

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