Three-coordinate measurement assisted five-axis machining compensation method and system and medium

Abstract

The invention provides a three-coordinate measurement assisted five-axis machining compensation method and system and a medium. The method comprises the following steps: detecting and determining the relative offset of a product coordinate system and a machine tool coordinate system by utilizing a leapfrogging function, processing a product to be processed, and acquiring space coordinate data of curved surface space points and feature point coordinate measurement data of an outline by utilizing a three-coordinate measuring instrument to analyze and process. The method comprises the following steps: acquiring a curved surface processing error and actual contour parameter data, acquiring a product image of a processed product for analysis and processing, generating a product digital model, and finally generating a five-axis processing compensation parameter according to the curved surface processing error, the actual contour parameter data and the product digital model; according to the method, the three-coordinate measurement assisted five-axis machining compensation is realized by configuring product machining basic parameters, initializing a tool path and a coordinate system, calibrating a workpiece and a machine tool coordinate system, collecting three-coordinate curved surface and contour dynamic data and analyzing and generating compensation parameters by utilizing an algorithm.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of five-axis precision manufacturing and precision three-coordinate programming control, in particular to a method, system and medium for three-coordinate measurement assisted five-axis machining compensation. BACKGROUND

[0002] In the field of five-axis precision machining, there has been a long-standing problem of precision control for machining complex curved surfaces, free contours, precision shapes and hole features. Due to the multi-axis linkage involved in five-axis machining, the error accumulation of spatial coordinates and theoretical design is significant. The traditional machining mode needs to correct the error through repeated machining and multiple debugging, resulting in high equipment occupancy, long machining cycle and low production efficiency, which is difficult to meet the demand of high precision and batch production. In the prior art, the machining parameter setting and measurement feedback are disconnected, and the actual size data of the part cannot be dynamically associated with the machining parameters in real time, resulting in lagging error compensation. Therefore, there is an urgent need for a collaborative technology that integrates three-coordinate measurement and five-axis machining to achieve accurate compensation and efficient control of the machining process.

[0003] In view of the above problems, an effective technical solution is urgently needed. SUMMARY

[0004] The purpose of the present application is to provide a method, system and medium for three-coordinate measurement assisted five-axis machining compensation, which can realize three-coordinate measurement assisted five-axis machining compensation by configuring product machining basic parameters, initializing tool path and coordinate system, calibrating workpiece and machine tool coordinate system, collecting three-coordinate curved surface and contour dynamic data, and using algorithm analysis and generating compensation parameters.

[0005] In the first aspect, the present application provides a method for three-coordinate measurement assisted five-axis machining compensation, comprising the following steps: Setting product machining basic parameters and product machining tool data in machine tool interface, database, variable program and model data; Detecting the initial edge coordinate data of the product to be machined according to the product machining basic parameters and product machining tool data through the skip function, and analyzing and processing to obtain the relative offset of the product coordinate system and the machine tool coordinate system; According to the product machining basic parameters and product machining tool data and the relative offset, the product to be machined is processed to obtain the machined product; Using a three-coordinate measuring instrument to collect the spatial coordinate data of the curved surface space point of the machined product, and comparing with the preset product model data to obtain the curved surface machining error; Using a three-coordinate measuring instrument to collect the feature point coordinate measurement data of the contour of the machined product, and analyzing and processing to obtain the actual contour parameter data of the machined product; Acquiring a product image of the machining product, and performing analysis and processing on the product image to generate a product digital model; According to the surface machining error, the actual contour parameter data, and the product digital model, a preset algorithm is used to perform analysis and processing to generate five-axis machining compensation parameters.

[0006] Optionally, in the method for three-coordinate measurement-assisted five-axis machining compensation, the product machining basic parameters and the product machining tool data are set in the machine tool interface, the database, the variable program, and the model data, including: The product machining basic parameters and the product machining tool data are set in the machine tool interface, the database, the variable program, and the model data; The product machining basic parameters include tool calling parameter data, rotary cycle parameter data, debugging parameter data, and feed rate. The product machining tool data includes tool compensation parameter data, tool initial position data, and coordinate system transformation parameter data.

[0007] Optionally, in the method for three-coordinate measurement-assisted five-axis machining compensation, the initial edge coordinate data of the product to be machined are detected by using a skip function according to the product machining basic parameters and the product machining tool data, and analysis and processing are performed to obtain the relative offset amount of the product coordinate system and the machine tool coordinate system, including: The initial edge coordinate data of the product to be machined in the machine tool coordinate system are acquired by triggering the probe to contact the edge of the product to be machined according to the product machining basic parameters and the product machining tool data by using a skip function; According to the initial coordinate data, preset machine tool mechanical coordinates, and preset probe compensation parameters, analysis and processing are performed to obtain actual edge coordinate data; According to the actual edge coordinate data, processing is performed to obtain the relative offset amount of the product coordinate system and the machine tool coordinate system.

[0008] Optionally, in the method for three-coordinate measurement-assisted five-axis machining compensation, the space coordinate data of the space points of the curved surface of the machining product are collected by using a three-coordinate measuring instrument, and are compared with preset product model data to obtain a surface machining error, including: The space coordinate data of the space points of the curved surface of the machining product are collected by using a three-coordinate measuring instrument to contact the machining product, and corresponding space coordinate data are obtained; The space coordinate data and the corresponding preset product model data are subjected to coordinate system alignment processing by using a least square method, and data preprocessing is performed to obtain optimized space coordinate data; The optimized space coordinate data and the theoretical space coordinate data of the corresponding space points in the preset product model data are compared to obtain a surface machining error in the normal direction.

[0009] Optionally, in the method for three-coordinate measurement assisted five-axis machining compensation, the feature point coordinate measurement data of the shape contour of the machining product is collected by using a three-coordinate measuring instrument, and is analyzed and processed to obtain actual contour parameter data of the machining product, including: collecting the feature point coordinate measurement data of the shape contour of the machining product by using a three-coordinate measuring instrument; calculating the feature point coordinate measurement data in combination with a preset probe radius value to obtain actual feature point coordinate data; processing the actual feature point coordinate data by using a preset triangulation calculation method to obtain actual contour parameter data of the machining product.

[0010] Optionally, in the method for three-coordinate measurement assisted five-axis machining compensation, the product image of the machining product is obtained, and the product digital model is generated by analyzing and processing the product image, including: collecting the product image by using a high-precision probe to obtain the product image; performing image preprocessing, contour edge detection and feature point recognition on the product image to obtain product geometric feature parameter data; processing the product geometric feature parameter data in combination with the surface machining error, the actual contour parameter data and the preset product model data by using a preset image matching and reconstruction method to generate the product digital model.

[0011] Optionally, in the method for three-coordinate measurement assisted five-axis machining compensation, the five-axis machining compensation parameters are generated by analyzing and processing the surface machining error, the actual contour parameter data and the product digital model by using a preset algorithm, including: performing error cluster analysis on the surface machining error, the actual contour parameter data and the product digital model in combination with the preset product model data to obtain machining system error, machining local error and machining surface quality error; processing the machining system error, the machining local error and the machining surface quality error by using a preset algorithm to generate the five-axis machining compensation parameters, including a tool length compensation correction value, a relative offset adjustment value and a feed rate optimization value.

[0012] In a second aspect, the application provides a system for three-coordinate measurement assisted five-axis machining compensation, which comprises a memory and a processor, the memory comprising a program of a method for three-coordinate measurement assisted five-axis machining compensation, and the program of the method for three-coordinate measurement assisted five-axis machining compensation is executed by the processor to realize the following steps: Setting product machining basic parameters and product machining tool data in machine tool interface, database, variable program and model data; Detecting initial edge coordinate data of the product to be machined according to the product machining basic parameters and the product machining tool data through a skip function, and performing analysis and processing to obtain a relative offset between a product coordinate system and a machine tool coordinate system; According to the product machining basic parameters and the product machining tool data and the relative offset, the product to be machined is machined to obtain a machined product; Using a three-coordinate measuring instrument to collect spatial coordinate data of a curved surface space point of the machined product, and comparing with preset product model data to obtain a curved surface machining error; Using a three-coordinate measuring instrument to collect feature point coordinate measurement data of an outline profile of the machined product, and performing analysis and processing to obtain actual outline parameter data of the machined product; Obtaining a product image of the machined product, and performing analysis and processing on the product image to generate a product digital model; According to the curved surface machining error, the actual outline parameter data and the product digital model, generating five-axis machining compensation parameters through a preset algorithm.

[0013] Optionally, in the three-coordinate measurement assisted five-axis machining compensation system, the setting of the product machining basic parameters and the product machining tool data in the machine tool interface, the database, the variable program and the model data comprises: Setting product machining basic parameters and product machining tool data in machine tool interface, database, variable program and model data; The product machining basic parameters comprise tool calling parameter data, rotary cycle parameter data, debugging parameter data and feed rate; The product machining tool data comprises tool compensation parameter data, tool initial position data and coordinate system transformation parameter data.

[0014] In a third aspect, the application further provides a computer readable storage medium, wherein a three-coordinate measurement assisted five-axis machining compensation method program is stored in the computer readable storage medium, and the three-coordinate measurement assisted five-axis machining compensation method program is executed by a processor to implement the steps of the three-coordinate measurement assisted five-axis machining compensation method according to any one of the above.

[0015] As can be seen from the above, the three-coordinate measurement assisted five-axis machining compensation method, system and medium provided by the application realize three-coordinate measurement assisted five-axis machining compensation by configuring product machining basic parameters, initializing tool path and coordinate system, calibrating workpiece and machine tool coordinate system, collecting three-coordinate curved surface and outline dynamic data, and generating compensation parameters through algorithm analysis.

[0016] Other features and advantages of the present application will be set forth in the following description, and in part will be apparent from the description, or can be learned by practice of the application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 A flow chart of a three-coordinate measurement auxiliary five-axis machining compensation method provided by the embodiments of the present application; Figure 2 A flow chart of obtaining a relative offset amount of a product coordinate system and a machine tool coordinate system of a three-coordinate measurement auxiliary five-axis machining compensation method provided by the embodiments of the present application; Figure 3 A flow chart of obtaining a curved surface machining error of a three-coordinate measurement auxiliary five-axis machining compensation method provided by the embodiments of the present application. DETAILED DESCRIPTION

[0019] The technical solutions of the embodiments of the present application will be described clearly and completely in the following with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0020] It should be noted that similar reference numerals and letters indicate similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0021] Reference will be made to Figure 1 , Figure 1is a flow chart of a method of three-coordinate measurement assisted five-axis machining compensation in some embodiments of the present application. The method of three-coordinate measurement assisted five-axis machining compensation is used in a terminal device, such as a computer, a mobile phone terminal, etc. The method of three-coordinate measurement assisted five-axis machining compensation comprises the following steps: S11, setting product machining basic parameters and product machining tool data in a machine tool interface, a database, a variable program and model data; S12, detecting initial edge coordinate data of a product to be machined according to the product machining basic parameters and the product machining tool data through a skip function, and performing analysis and processing to obtain a relative offset amount of a product coordinate system and a machine tool coordinate system; S13, performing product machining on the product to be machined according to the product machining basic parameters and the product machining tool data and the relative offset amount, and obtaining a machined product; S141, collecting spatial coordinate data of a curved surface space point of the machined product by using a three-coordinate measuring instrument, and comparing with preset product model data to obtain a curved surface machining error; S142, collecting feature point coordinate measurement data of an outline profile of the machined product by using the three-coordinate measuring instrument, and performing analysis and processing to obtain actual profile parameter data of the machined product; S143, obtaining a product image of the machined product, performing analysis and processing according to the product image, and generating a product digital model; S15, generating five-axis machining compensation parameters through preset algorithm analysis and processing according to the curved surface machining error, the actual profile parameter data and the product digital model.

[0022] It should be noted that the present application first sets machining basic parameters in a machine tool interface, and completes tool path initialization according to code instructions, then, through a skip program, a probe is allowed to touch a workpiece edge at a given feed rate, positive and negative edge coordinates are calculated, an offset amount of a workpiece origin in a machine tool coordinate system is determined, machining is performed on a product to be machined, after machining, spatial coordinate data of a curved surface space point and feature point coordinate measurement data of an outline profile are collected according to a planned path by using a three-coordinate measuring instrument, curved surface machining error and actual profile parameter data are generated after processing, finally, three-dimensional reconstruction of a machined product is performed, compensation parameters are output after comparison with preset product model data.

[0023] According to the embodiment of the present application, the setting of product machining basic parameters and product machining tool data in a machine tool interface, a database, a variable program and model data comprises: setting product machining basic parameters and product machining tool data in a machine tool interface, a database, a variable program and model data; The product processing basic parameters include tool calling parameter data, rotation cycle parameter data, tuning parameter data and feed rate; The product processing tool data includes tool compensation parameter data, tool initial position data and coordinate system transformation parameter data.

[0024] It should be noted that the tool calling parameter data is used to specify the tool type, number and basic attribute data of the tool used for processing, the rotation cycle parameter data defines the motion rules of the five-axis machine tool rotation axis (such as A axis, B axis), including rotation mode and set initial rotation angle, the tuning parameter data is used to control the auxiliary parameters of processing precision and process stability, including tolerance parameter and measurement and processing coordination mode, the feed rate refers to the feed rate of each axis of the machine tool; The tool compensation parameter data is used to correct the deviation between the actual size of the tool and the theoretical value, including length compensation value and radius compensation parameter, the tool initial position data defines the safe starting point and tool changing position of the tool, and the coordinate system transformation parameter data is used to adjust the relative coordinate system of the tool and the workpiece, which provides a unified and accurate reference for subsequent coordinate system calibration, processing execution and error compensation, and is the prerequisite to ensure the five-axis machining precision; Product processing basic parameter setting example: 37 TOOL CALL 8 Z S4356 38 TOOL DEF 2 39 CYCL DEF 10.0 ROTATION 40 CYCL DEF 10.1 ROT 0.0 41 CYCL DEF 332 Tuning Q395=0;Tuning Mode Q396=0;Tolerance Q397=0;TA 42 FN 0:Q1=456 ; XY FEED RATE 43 FN 0:Q2=456 ; Z FEED RATE Product processing tool data parameter setting example: G43.4 H4 G0 G90 X632.3223 Y211.3928 B26.099 C230.415 G0 X632.3223 Y211.3928 Z63.1065 B26.099 C230.415 G49 G68.2 X719.504 Y169.2225 Z-92.6305 I-39.585 J26.099 K-20.096 G53.1 P0 (B26.099 C230.415 ) G61.1 G0 G43 H4 X-104.7605 Y12.5778 Z150. M8 G0 Z26.5 G5P2.

[0025] Please refer to Figure 2 , Figure 2 This is a flow chart of obtaining the relative offset between the product coordinate system and the machine tool coordinate system in a method for three-coordinate measurement-assisted five-axis machining compensation in some embodiments of the present application. According to an embodiment of the present invention, the initial edge coordinate data of the product to be machined is detected by the skip function based on the basic product machining parameters and product machining tool data, and analyzed and processed to obtain the relative offset between the product coordinate system and the machine tool coordinate system, including: S21, triggering the probe to contact the edge of the product to be processed through the skip function according to the product processing basic parameters and product processing tool data, and obtaining initial edge coordinate data of the product to be processed in the machine tool coordinate system; S22, analyzing and processing the initial coordinate data in combination with preset machine tool mechanical coordinates and preset probe compensation parameters to obtain actual edge coordinate data; S23. Process the actual edge coordinate data to obtain a relative offset between the product coordinate system and the machine tool coordinate system.

[0026] It should be noted that when the probe touches the edge of the workpiece to generate a trigger signal, the machine tool system will record the preset machine tool mechanical coordinates at the moment of triggering. The preset machine tool mechanical coordinates are absolute coordinates in the machine tool's own reference coordinate system (such as the machine tool origin), reflecting the real-time position of the probe center in the machine tool space. The preset probe compensation parameters are combined for calculation to obtain actual edge coordinate data. The preset probe compensation parameters include probe length compensation parameters and probe radius compensation parameters. The actual edge coordinate data includes positive edge coordinate data and negative edge coordinate data. Taking the X direction as an example, the positive edge coordinate data is the sum of the initial X-direction edge coordinate data, the probe length compensation parameter, and the probe radius compensation parameter. The negative edge coordinate data is the sum of the initial X-direction edge coordinate data and the probe length compensation parameter minus the probe radius compensation parameter. The average of the positive edge coordinate data and the negative edge coordinate data is the relative offset between the product coordinate system and the machine tool coordinate system. Similarly, technicians can obtain the relative offset and angular offset in the Y and Z directions.

[0027] Referring to Figure 3 , Figure 3 is a flowchart of a method for obtaining a surface machining error in a three-coordinate measurement auxiliary five-axis machining compensation method in some embodiments of the present application. According to an embodiment of the present application, the spatial coordinate data of the surface space points of the machining product is collected by using a three-coordinate measuring instrument, and is compared with the preset product model data to obtain the surface machining error, comprising: S31, collecting data of a plurality of space points on the surface of the machining product by using a three-coordinate measuring instrument to obtain corresponding spatial coordinate data; S32, aligning the spatial coordinate data and the corresponding preset product model data in the coordinate system by using the least square method, and performing data preprocessing to obtain optimized spatial coordinate data; S33, comparing the optimized spatial coordinate data with the theoretical spatial coordinate data of the corresponding space points in the preset product model data to obtain the normal direction surface machining error.

[0028] It should be noted that, by comparing the spatial coordinate data of the surface obtained by the three-coordinate measurement with the theoretical data of the design model, the deviation value of each point of the surface is quantified by means of the algorithm operation of the measurement software, and finally the error data which can be used for machining compensation is formed. First, the spatial coordinate data and the corresponding preset product model data are aligned in the coordinate system by using the least square method, and the systematic deviation caused by the workpiece clamping and the coordinate system setting is eliminated. Then, it is converted into a format that can be recognized by the measurement software. For each measured point, its corresponding theoretical point on the theoretical surface is found, the distance deviation of the two points in the normal direction (perpendicular to the direction of the point on the theoretical surface) is calculated, and the normal direction surface machining error is obtained.

[0029] According to an embodiment of the present application, the feature point coordinate measurement data of the contour profile of the machining product is collected by using a three-coordinate measuring instrument, and is analyzed and processed to obtain the actual contour parameter data of the machining product, comprising: collecting the feature point coordinate measurement data of the contour profile of the machining product by using a three-coordinate measuring instrument; combining the feature point coordinate measurement data with a preset probe radius value to calculate the actual feature point coordinate data; processing the actual feature point coordinate data by using a preset triangulation calculation method to obtain the actual contour parameter data of the machining product.

[0030] It should be noted that, based on the profile discrete point coordinates obtained by three-coordinate measurement, the geometric relationship is restored through triangulation principle, and the actual profile parameter data of the processed product is finally calculated by combining the preset probe radius value. Firstly, the three-dimensional coordinates (X, Y, Z) of the effective measurement points are extracted from the feature point coordinate measurement data of the contour profile, and these points are distributed along the edge of the workpiece profile (such as the edge, the arc boundary, and the corner), and the key features (such as the starting point, the ending point, and the inflection point) of the profile are ensured to be covered. Then, the feature point coordinate measurement data of the three-coordinate measurement is the probe center coordinate. Since the probe is spherical, the measurement point when contacting the workpiece is the probe center position, and the preset probe radius value needs to be subtracted to obtain the actual surface coordinate of the workpiece. According to the normal direction (the direction perpendicular to the profile surface) of the profile point, the probe center coordinate is offset by the preset probe radius value (such as the probe ball diameter of 2mm, the radius of 1mm, and the offset amount of 1mm) along the normal direction to the inside of the workpiece, to obtain the actual data of the feature point coordinate of the workpiece profile. The feature point coordinate actual data is the difference between the feature point coordinate measurement data and the radius and normal vector multiplication machine, that is, the feature point coordinate actual data = feature point coordinate measurement data - radius x normal vector. Finally, the geometric parameters of the profile are restored by calculating the distance and angle of adjacent points through the coordinates of the profile points by using the geometric characteristics of three points determining a triangle, including the actual size, the actual angle, and the geometric shape error, and then compared with the preset product model data to obtain the geometric shape error, so as to generate the actual profile parameter data including the actual size, the actual angle, and the geometric shape error.

[0031] According to the embodiment of the present application, the product image of the processed product is obtained, and the product digital model is generated by analyzing and processing the product image, including: The image of the processed product is collected by a high-precision probe to obtain the processed product image. The processed product image is preprocessed, the contour edge is detected, and the feature points are recognized to obtain the product geometric feature parameter data. The product digital model is generated by processing the product geometric feature parameter data, the curved surface processing error, the actual profile parameter data, and the preset product model data through a preset image matching and reconstruction method.

[0032] It should be noted that the application converts two-dimensional image information into accurate three-dimensional digital model through feature extraction, matching reconstruction and error correction of image data, provides high-quality visual measurement data for subsequent processing compensation, first, the original image is preprocessed by noise reduction, contrast enhancement and binarization, edge detection algorithm (such as Canny operator, Sobel operator) is used to identify the pixel points with gray value mutation in the image, and the continuous edge line segments are connected, the edge line segments are morphologically processed (such as corrosion, expansion), burrs or fractures are removed, smooth and complete workpiece outer contour is obtained, then Harris corner point detection algorithm is used to identify the corner points (such as intersection angle of curved surface and plane, turning point of stepped contour) in the contour, mark the pixel coordinates, convert the extracted contour edge into mathematical parameters (such as slope of straight line, curvature of circular arc), convert the corner points into (x, y) pixel coordinates, finally, three-dimensional digital model is generated from two-dimensional image through image matching (including feature point matching and coordinate system alignment) and three-dimensional reconstruction, and product digital model is obtained.

[0033] According to the embodiment of the application, the five-axis machining compensation parameters are generated by preset algorithm analysis and processing according to the curved surface machining error, actual contour parameter data and product digital model, including: The curved surface machining error, actual contour parameter data and product digital model are combined with preset product model data to perform error clustering analysis, to obtain machining system error, machining local error and machining surface quality error; The five-axis machining compensation parameters are generated by preset algorithm processing according to the machining system error, machining local error and machining surface quality error, including tool length compensation correction value, relative offset adjustment value and feed rate optimization value.

[0034] It should be noted that, according to the surface machining error, the actual contour parameter data and the product digital model, the error source is determined by systematic analysis combined with the preset product model data, and finally converted into specific compensation parameters executable by the machine tool, wherein the machining system error is that the whole surface deviates to a certain direction (such as X axis +0.03mm), the local machining error is that the surface of a certain area is concave (deviation-0.04mm), and the machining surface quality error is that the surface appears periodic corrugation (deviation ±0.01mm). For different types of errors, the specific compensation value is determined combined with the error data. For example, the whole surface normal deviation ΔZ is +0.02mm, and the tool length compensation correction value is +ΔZ, that is, the corresponding compensation value is increased from the original 0.05mm to 0.07mm. The whole X, Y and Z axis deviation is directly used as the coordinate system adjustment value, and the offset parameter of the workpiece coordinate system is corrected. The X axis offset is adjusted from the original 0 to-0.03mm, which offsets the +0.03mm deviation measured. If the corrugation deviation is ±0.01mm, the feed rate is reduced according to the empirical formula (such as the positive correlation between the feed rate and the corrugation amplitude), and the feed rate is adjusted from 456mm / min to 400mm / min.

[0035] It is worth mentioning that, according to the embodiment of the application, further comprising: The environment measured temperature and probe wear compensation value when acquiring the product image of the machining product are acquired; The temperature drift compensation value is obtained according to the environment measured temperature combined with the preset nominal temperature and the preset product thermal expansion coefficient; The product geometric feature parameter data is corrected according to the temperature drift compensation value and the probe wear compensation value, and the product geometric feature parameter correction data is obtained.

[0036] It should be noted that the image measurement data may be affected by the environment temperature and the probe wear to produce deviation. The environment measured temperature is acquired first, and the temperature drift compensation value is obtained by calculating combined with the preset nominal temperature and the preset product thermal expansion coefficient, that is, (environment measured temperature-pre-set nominal temperature) x preset product thermal expansion coefficient x product geometric feature parameter data. If it is positive, it is corrected in the opposite direction, that is, the temperature drift compensation value is subtracted. If it is negative, it is corrected in the positive direction, that is, the temperature drift compensation value is added. The probe wear compensation value is obtained by recording the number of times of using the probe and the cumulative working time, and analyzing combined with the probe wear calibration curve. The feature size (such as the pixel distance of the contour edge) in the image based on the probe imaging is compensated, and the imaging error caused by the probe wear is corrected.

[0037] The application further discloses a system for three-coordinate measurement-assisted five-axis machining compensation, comprising a memory and a processor, the memory comprising a three-coordinate measurement-assisted five-axis machining compensation method program, and the three-coordinate measurement-assisted five-axis machining compensation method program is executed by the processor to realize the following steps: product machining basic parameters and product machining tool data are set in a machine tool interface, a database, a variable program and model data; initial edge coordinate data of a product to be machined are detected by a skip function according to the product machining basic parameters and the product machining tool data, and are analyzed and processed to obtain a relative offset between a product coordinate system and a machine tool coordinate system; the product to be machined is machined according to the product machining basic parameters, the product machining tool data and the relative offset to obtain a machined product; spatial coordinate data of a curved surface space point of the machined product are collected by a three-coordinate measuring instrument, and are compared with preset product model data to obtain a curved surface machining error; feature point coordinate measurement data of an outline profile of the machined product are collected by the three-coordinate measuring instrument, and are analyzed and processed to obtain actual profile parameter data of the machined product; a product image of the machined product is obtained, and the product image is analyzed and processed to generate a product digital model; five-axis machining compensation parameters are generated by preset algorithm analysis and processing according to the curved surface machining error, the actual profile parameter data and the product digital model.

[0038] It should be noted that the application firstly sets machining basic parameters in a machine tool interface, and initializes a tool path according to code instructions, then a probe is made to touch an edge of a workpiece at a given feed rate by a skip program, positive and negative edge coordinates are calculated, an offset of a workpiece origin in a machine tool coordinate system is determined, machining is implemented on a product to be machined, spatial coordinate data of a curved surface space point and feature point coordinate measurement data of an outline profile of the machined product are collected by a three-coordinate measuring instrument according to a planned path after machining, curved surface machining error and actual profile parameter data are generated after processing, finally, three-dimensional reconstruction of the machined product is performed, compensation parameters are output after comparison with preset product model data.

[0039] According to the embodiment of the application, the product machining basic parameters and the product machining tool data are set in the machine tool interface, the database, the variable program and the model data, comprising: product machining basic parameters and product machining tool data are set in a machine tool interface, a database, a variable program and model data; the product machining basic parameters comprise tool calling parameter data, rotary cycle parameter data, debugging parameter data and a feed rate; The product machining tool data includes tool compensation parameter data, tool initial position data and coordinate system transformation parameter data.

[0040] It should be noted that the tool call parameter data is used to specify the tool type, number and basic attribute data of the tool used for machining, the rotary cycle parameter data defines the motion rules of the rotary axis (such as A axis, B axis) of the five-axis machine tool, including rotary mode and set initial rotary angle, the debugging parameter data is used to control the auxiliary parameters of machining precision and process stability, including tolerance parameter and measurement and machining coordination mode, the feed rate refers to the feed rate of each axis of the machine tool; The tool compensation parameter data is used to correct the deviation between the actual size of the tool and the theoretical value, including length compensation value and radius compensation parameter, the tool initial position data defines the safe starting point and tool changing position of the tool, and the coordinate system transformation parameter data is used to adjust the relative coordinate system of the tool and the workpiece, which provides a unified and accurate reference for subsequent coordinate system calibration, machining execution and error compensation, and is the prerequisite to ensure the machining precision of five-axis machining; Product machining basic parameter setting example: 37 TOOL CALL 8 Z S4356 38 TOOL DEF 2 39 CYCL DEF 10.0 ROTATION 40 CYCL DEF 10.1 ROT 0.0 41 CYCL DEF 332 Tuning Q395=0;Tuning Mode Q396=0;Tolerance Q397=0;TA 42 FN 0:Q1=456 ; XY FEED RATE 43 FN 0:Q2=456 ; Z FEED RATE Product machining tool data parameter setting example: G43.4 H4 G0 G90 X632.3223 Y211.3928 B26.099 C230.415 G0 X632.3223 Y211.3928 Z63.1065 B26.099 C230.415 G49 G68.2 X719.504 Y169.2225 Z-92.6305 I-39.585 J26.099 K-20.096 G53.1 P0 (B26.099 C230.415 ) G61.1 G0 G43 H4 X-104.7605 Y12.5778 Z150. M8 G0 Z26.5 G5P2。

[0041] According to the embodiment of the present application, the initial edge coordinate data of the product to be processed is detected by the skip function according to the product processing basic parameters and product processing tool data, and is analyzed and processed to obtain the relative offset of the product coordinate system and the machine tool coordinate system, including: The initial edge coordinate data of the product to be processed in the machine tool coordinate system is obtained by triggering the probe to contact the edge of the product to be processed by the skip function according to the product processing basic parameters and product processing tool data; The actual edge coordinate data is obtained by analyzing and processing the initial coordinate data in combination with the preset machine tool mechanical coordinate and the preset probe compensation parameter; The relative offset of the product coordinate system and the machine tool coordinate system is obtained by processing the actual edge coordinate data.

[0042] It should be noted that the trigger signal is generated by the probe touching the edge of the workpiece, and at this time the machine tool system will record the preset machine tool mechanical coordinate at the triggering moment. The preset machine tool mechanical coordinate is the absolute coordinate under the machine tool itself reference coordinate system (such as the machine tool origin), which reflects the real-time position of the probe center in the machine tool space. The actual edge coordinate data is obtained by combining the preset probe compensation parameter for calculation, wherein the preset probe compensation parameter includes the probe length compensation parameter and the probe radius compensation parameter, and the actual edge coordinate data includes the positive edge coordinate data and the negative edge coordinate data. Taking the X direction as an example, the positive edge coordinate data is the sum of the initial edge coordinate data, the probe length compensation parameter and the probe radius compensation parameter in the X direction, and the negative edge coordinate data is the sum of the initial edge coordinate data and the probe length compensation parameter in the X direction minus the probe radius compensation parameter. The relative offset of the product coordinate system and the machine tool coordinate system is obtained by averaging the positive edge coordinate data and the negative edge coordinate data. Similarly, the relative offset in the Y and Z directions and the angle offset can be obtained by the skilled person.

[0043] According to the embodiment of the present application, the space coordinate data of the curved surface space points of the processed product is collected by the three-coordinate measuring instrument, and is compared with the preset product model data to obtain the curved surface processing error, including: The space coordinate data corresponding to the plurality of space points is obtained by collecting the data of the plurality of space points on the curved surface of the processed product by the three-coordinate measuring instrument; The space coordinate data is aligned with corresponding preset product model data through least square method for coordinate system alignment processing, and data preprocessing is performed to obtain optimized space coordinate data. The optimized space coordinate data is compared with theoretical space coordinate data of corresponding space points in the preset product model data to obtain the normal direction surface machining error.

[0044] It should be noted that, by comparing the space coordinate data of the surface obtained by three-coordinate measurement with the theoretical data of the design model, the deviation value of each point of the surface is quantified by means of the algorithm operation of the measurement software, and finally the error data which can be used for machining compensation is formed. Firstly, the space coordinate data is aligned with corresponding preset product model data through least square method for coordinate system alignment processing, and the systematic deviation caused by workpiece clamping and coordinate system setting is eliminated. Then, it is converted into a format that can be recognized by the measurement software. For each measured point, its corresponding theoretical point on the theoretical surface is found, the distance deviation of the two points in the normal direction (perpendicular to the direction of the point on the theoretical surface) is calculated, and the normal direction surface machining error is obtained.

[0045] According to the embodiment of the present application, the feature point coordinate measurement data of the shape contour of the machining product is collected by using a three-coordinate measuring instrument, and is analyzed and processed to obtain actual contour parameter data of the machining product, including: The feature point coordinate measurement data of the shape contour of the machining product is collected by using a three-coordinate measuring instrument; The feature point coordinate measurement data is combined with a preset probe radius value for calculation to obtain actual feature point coordinate data; The actual feature point coordinate data is processed through a preset triangulation calculation method to obtain actual contour parameter data of the machining product.

[0046] It should be noted that, based on the profile discrete point coordinates obtained by three-coordinate measurement, the geometric relationship is restored through triangulation principle, and the actual profile parameter data of the processed product is finally calculated by combining the preset probe radius value. Firstly, the three-dimensional coordinates (X, Y, Z) of the effective measurement points are extracted from the feature point coordinate measurement data of the contour profile, and these points are distributed along the edge of the workpiece profile (such as the edge, the arc boundary, and the corner), and the key features (such as the starting point, the ending point, and the inflection point) of the profile are ensured to be covered. Then, the feature point coordinate measurement data of the three-coordinate measurement is the probe center coordinate. Since the probe is spherical, the measurement point when contacting the workpiece is the probe center position, and the preset probe radius value needs to be subtracted to obtain the actual surface coordinate of the workpiece. According to the normal direction (the direction perpendicular to the profile surface) of the profile point, the probe center coordinate is offset by the preset probe radius value (such as the probe ball diameter of 2mm, the radius of 1mm, and the offset amount of 1mm) along the normal direction to the inside of the workpiece, to obtain the actual data of the feature point coordinate of the workpiece profile. The feature point coordinate actual data is the difference between the feature point coordinate measurement data and the radius and normal vector multiplication machine, that is, the feature point coordinate actual data = feature point coordinate measurement data - radius x normal vector. Finally, the geometric parameters of the profile are restored by calculating the distance and angle of adjacent points through the coordinates of the profile points by using the geometric characteristics of three points determining a triangle, including the actual size, the actual angle, and the geometric shape error, and then compared with the preset product model data to obtain the geometric shape error, so as to generate the actual profile parameter data including the actual size, the actual angle, and the geometric shape error.

[0047] According to the embodiment of the present application, the product image of the processed product is obtained, and the product digital model is generated by analyzing and processing the product image, including: The image of the processed product is collected by a high-precision probe to obtain the processed product image; The processed product image is preprocessed, the contour edge is detected, and the feature points are recognized to obtain the product geometric feature parameter data; The product digital model is generated by processing the product geometric feature parameter data, the curved surface processing error, the actual profile parameter data, and the preset product model data through a preset image matching and reconstruction method.

[0048] It should be noted that the application converts two-dimensional image information into accurate three-dimensional digital model through feature extraction, matching reconstruction and error correction of image data, provides high-quality visual measurement data for subsequent processing compensation, first, the original image is preprocessed by noise reduction, contrast enhancement and binarization, edge detection algorithm (such as Canny operator, Sobel operator) is used to identify the pixel points with gray value mutation in the image, and the continuous edge line segments are connected, the edge line segments are morphologically processed (such as corrosion, expansion), burrs or fractures are removed, smooth and complete workpiece outer contour is obtained, then Harris corner point detection algorithm is used to identify the corner points (such as intersection angle of curved surface and plane, turning point of stepped contour) in the contour, mark the pixel coordinates, convert the extracted contour edge into mathematical parameters (such as slope of straight line, curvature of circular arc), convert the corner points into (x, y) pixel coordinates, finally, three-dimensional digital model is generated from two-dimensional image through image matching (including feature point matching and coordinate system alignment) and three-dimensional reconstruction, and product digital model is obtained.

[0049] According to the embodiment of the application, the five-axis machining compensation parameters are generated by preset algorithm analysis and processing according to the curved surface machining error, actual contour parameter data and product digital model, including: The curved surface machining error, actual contour parameter data and product digital model are combined with preset product model data to perform error clustering analysis, and machining system error, machining local error and machining surface quality error are obtained; The five-axis machining compensation parameters are generated by preset algorithm processing according to the machining system error, machining local error and machining surface quality error, including tool length compensation correction value, relative offset adjustment value and feed rate optimization value.

[0050] It should be noted that, according to the surface machining error, the actual contour parameter data and the product digital model, the error source is determined by systematic analysis combined with the preset product model data, and finally converted into specific compensation parameters executable by the machine tool, wherein the machining system error is that the whole surface deviates to a certain direction (such as X axis +0.03mm), the local machining error is that the surface of a certain area is concave (deviation-0.04mm), and the machining surface quality error is that the surface appears periodic corrugation (deviation ±0.01mm). For different types of errors, the specific compensation value is determined combined with the error data. For example, the whole surface normal deviation ΔZ is +0.02mm, and the tool length compensation correction value is +ΔZ, that is, the corresponding compensation value is increased from the original 0.05mm to 0.07mm. The whole X, Y and Z axis deviation is directly used as the coordinate system adjustment value, and the offset parameter of the workpiece coordinate system is corrected. The X axis offset is adjusted from the original 0 to-0.03mm, which offsets the +0.03mm deviation measured. If the corrugation deviation is ±0.01mm, the feed rate is reduced according to the empirical formula (such as the positive correlation between the feed rate and the corrugation amplitude), and the feed rate is adjusted from 456mm / min to 400mm / min.

[0051] It is worth mentioning that, according to the embodiment of the application, further comprising: The environment measured temperature and probe wear compensation value when acquiring the product image of the machining product are acquired; The temperature drift compensation value is obtained according to the environment measured temperature combined with the preset nominal temperature and the preset product thermal expansion coefficient; The product geometric feature parameter data is corrected according to the temperature drift compensation value and the probe wear compensation value, and the product geometric feature parameter correction data is obtained.

[0052] It should be noted that the image measurement data may be affected by the environment temperature and the probe wear to produce deviation. The environment measured temperature is acquired first, and the temperature drift compensation value is obtained by calculating combined with the preset nominal temperature and the preset product thermal expansion coefficient, that is, (environment measured temperature-pre-set nominal temperature) x preset product thermal expansion coefficient x product geometric feature parameter data. If it is positive, it is corrected in the opposite direction, that is, the temperature drift compensation value is subtracted. If it is negative, it is corrected in the positive direction, that is, the temperature drift compensation value is added. The probe wear compensation value is obtained by recording the number of times of using the probe and the cumulative working time, and analyzing combined with the probe wear calibration curve. The feature size (such as the pixel distance of the contour edge) in the image based on the probe imaging is compensated, and the imaging error caused by the probe wear is corrected.

[0053] The third aspect of the present application provides a readable storage medium, wherein a three-coordinate measurement assisted five-axis machining compensation method program is stored in the readable storage medium, and the three-coordinate measurement assisted five-axis machining compensation method program is executed by a processor to realize the steps of the three-coordinate measurement assisted five-axis machining compensation method according to any one of the preceding aspects.

[0054] The present application discloses a three-coordinate measurement assisted five-axis machining compensation method, system and medium, which realizes three-coordinate measurement assisted five-axis machining compensation by configuring product machining basic parameters, initializing a tool path and a coordinate system, calibrating a workpiece and a machine tool coordinate system, collecting three-coordinate curved surface and contour dynamic data, and generating compensation parameters by using an algorithm.

[0055] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other manners. The above-described device embodiments are merely illustrative, for example, the division of the units is only a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the various components shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0056] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units; they can be located in one place, or distributed on multiple network units; and part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment.

[0057] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be realized in the form of hardware, or in the form of hardware plus software functional units.

[0058] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware, and the foregoing program can be stored in a readable storage medium, and the program is executed to perform the steps of the above-mentioned method embodiments; and the foregoing storage medium includes mobile storage devices, read-only memories (ROMs), random access memories (RAMs), magnetic discs or optical discs and various storage medium capable of storing program codes.

[0059] Alternatively, the above-mentioned integrated unit of the present application, if realized in the form of a software function module and sold or used as an independent product, can also be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: mobile storage devices, ROM, RAM, magnetic discs or optical discs, and various media capable of storing program codes.

Claims

1. A method for three-coordinate measurement-assisted five-axis machining compensation, characterized in that: The following steps are involved: Set product processing basic parameters and product processing tool data in the machine tool interface, database, variable program and model data; Detecting the initial edge coordinate data of the product to be processed through the skip function according to the product processing basic parameters and product processing tool data, and analyzing and processing the data to obtain the relative offset between the product coordinate system and the machine tool coordinate system; Processing the product to be processed according to the product processing basic parameters, product processing tool data and the relative offset to obtain a processed product; Collecting spatial coordinate data of surface spatial points of the processed product using a three-dimensional coordinate measuring machine, and comparing the data with preset product model data to obtain surface processing errors; Collecting coordinate measurement data of characteristic points of the outer contour of the processed product using a three-coordinate measuring machine, and analyzing and processing the data to obtain actual contour parameter data of the processed product; Acquire a product image of the processed product, analyze and process the product image, and generate a digital model of the product; The five-axis machining compensation parameters are generated based on the surface machining error, actual contour parameter data and product digital model through preset algorithm analysis and processing.

2. The method of three-coordinate measurement assisted five-axis machining compensation according to claim 1, characterized in that: The setting of product processing basic parameters and product processing tool data in the machine tool interface, database, variable program and model data includes: Set product processing basic parameters and product processing tool data in the machine tool interface, database, variable program and model data; The basic parameters for product processing include tool call parameter data, rotation cycle parameter data, debugging parameter data and feed rate; The product processing tool data includes tool compensation parameter data, tool initial position data and coordinate system transformation parameter data.

3. The method of three-coordinate measurement assisted five-axis machining compensation according to claim 2, characterized in that: The detecting of the initial edge coordinate data of the product to be processed by the skip function according to the product processing basic parameters and the product processing tool data, and performing analysis and processing to obtain the relative offset between the product coordinate system and the machine tool coordinate system includes: According to the basic product processing parameters and product processing tool data, the probe is triggered to contact the edge of the product to be processed through the skip function to obtain the initial edge coordinate data of the product to be processed in the machine tool coordinate system; Analyze and process the initial coordinate data in combination with preset machine tool mechanical coordinates and preset probe compensation parameters to obtain actual edge coordinate data; Processing is performed based on the actual edge coordinate data to obtain a relative offset between the product coordinate system and the machine tool coordinate system.

4. The method of three-coordinate measurement assisted five-axis machining compensation according to claim 3, characterized in that: The method of collecting spatial coordinate data of surface spatial points of the processed product using a three-dimensional coordinate measuring machine and comparing the data with preset product model data to obtain surface processing errors includes: The processed product is contacted with a three-dimensional coordinate measuring machine to collect data on a plurality of spatial points on the curved surface of the processed product to obtain corresponding spatial coordinate data; The spatial coordinate data and the corresponding preset product model data are aligned with each other using the least square method, and data preprocessing is performed to obtain optimized spatial coordinate data; The optimized spatial coordinate data is compared with the theoretical spatial coordinate data of the corresponding spatial point in the preset product model data to obtain the surface processing error in the normal direction.

5. The method of three-coordinate measurement assisted five-axis machining compensation according to claim 4, characterized in that: The method of collecting characteristic point coordinate measurement data of the outer contour of the processed product using a three-coordinate measuring machine and analyzing and processing the data to obtain actual contour parameter data of the processed product includes: Collecting coordinate measurement data of feature points of the outer contour of the processed product using a three-coordinate measuring machine; Calculate the feature point coordinate measurement data in combination with a preset probe radius value to obtain actual feature point coordinate data; The actual data of the feature point coordinates are processed using a preset triangulation calculation method to obtain actual contour parameter data of the processed product.

6. The method of three-coordinate measurement assisted five-axis machining compensation according to claim 5, characterized in that: The step of obtaining a product image of the processed product, analyzing and processing the product image, and generating a digital product model includes: Capturing images of the processed product using a high-precision probe to obtain images of the processed product; Performing image preprocessing, contour edge detection, and feature point recognition on the processed product image to obtain product geometric feature parameter data; The product geometric feature parameter data is combined with the surface processing error and actual contour parameter data and the preset product model data through a preset image matching and reconstruction method to generate a product digital model.

7. The method of three-coordinate measurement assisted five-axis machining compensation according to claim 6, characterized in that: The five-axis machining compensation parameters are generated by analyzing and processing the surface machining error, actual contour parameter data and the product digital model through a preset algorithm, including: The surface machining error, actual contour parameter data and product digital model are combined with preset product model data to perform error cluster analysis to obtain machining system error, machining local error and machining surface quality error; The machining system error, machining local error and machining surface quality error are processed by a preset algorithm to generate five-axis machining compensation parameters, including tool length compensation correction value, relative offset adjustment value and feed rate optimization value.

8. A system for three-coordinate measurement-assisted five-axis machining compensation, characterized in that: The system comprises a memory and a processor, wherein the memory comprises a program of a method for three-coordinate measurement-assisted five-axis machining compensation, and when the program of the method for three-coordinate measurement-assisted five-axis machining compensation is executed by the processor, the following steps are implemented: Set product processing basic parameters and product processing tool data in the machine tool interface, database, variable program and model data; Detecting the initial edge coordinate data of the product to be processed through the skip function according to the product processing basic parameters and product processing tool data, and analyzing and processing the data to obtain the relative offset between the product coordinate system and the machine tool coordinate system; Processing the product to be processed according to the product processing basic parameters, product processing tool data and the relative offset to obtain a processed product; Collecting spatial coordinate data of surface spatial points of the processed product using a three-dimensional coordinate measuring machine, and comparing the data with preset product model data to obtain surface processing errors; Collecting coordinate measurement data of characteristic points of the outer contour of the processed product using a three-coordinate measuring machine, and analyzing and processing the data to obtain actual contour parameter data of the processed product; Acquire a product image of the processed product, analyze and process the product image, and generate a digital model of the product; The five-axis machining compensation parameters are generated based on the surface machining error, actual contour parameter data and product digital model through preset algorithm analysis and processing.

9. The three-coordinate measurement assisted five-axis machining compensation system according to claim 8, characterized in that: The setting of product processing basic parameters and product processing tool data in the machine tool interface, database, variable program and model data includes: Set product processing basic parameters and product processing tool data in the machine tool interface, database, variable program and model data; The basic parameters for product processing include tool call parameter data, rotation cycle parameter data, debugging parameter data and feed rate; The product processing tool data includes tool compensation parameter data, tool initial position data and coordinate system transformation parameter data.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a method program for three-coordinate measurement-assisted five-axis machining compensation. When the method program for three-coordinate measurement-assisted five-axis machining compensation is executed by a processor, the steps of a method for three-coordinate measurement-assisted five-axis machining compensation as described in any one of claims 1 to 7 are implemented.

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