On-machine measurement calibration device and calibration method of non-standard five-axis machine tool

Abstract

The invention provides an on-machine measurement calibration device and calibration method for a non-standard five-axis machine tool, and the method comprises the steps: S1, setting a coordinate system of the non-standard five-axis machine tool, and installing a cutter handle on a main shaft; s2, configuring a calibration device which comprises a first reference plane and a plurality of positioning spheres; s3, keeping the initial positions of the rotating shafts unchanged; a probe is arranged at the tail end of the knife handle; s4, three-dimensional coordinate values of sphere centers of a plurality of positioning spheres under the coordinate system are obtained through contact measurement of the probe; s5, the probe is removed, a surface structured light three-dimensional scanner is installed at the tail end of the cutter handle, and three-dimensional coordinate values of the centers of the multiple positioning spheres are obtained; and S6, solving the three-dimensional coordinate value of the sphere center, and establishing a corresponding relation between the coordinate system of the surface structured light three-dimensional scanner and the coordinate system of the non-standard five-axis machine tool without moving the machine tool for many times to obtain data of the calibration device. According to the method, the feature point positioning and calibration process can be realized only by matching single measurement of the surface result light sensor on the calibration device with four-point measurement of the probe.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional measurement calibration methods, and in particular to an on-machine measurement calibration device and calibration method for a non-standard five-axis machine tool. Background Art

[0002] On-machine measurement technology, with its advantages of low cost and process detectability, is widely used to measure various complex curved parts. Currently, on-machine measurement technologies are primarily categorized into contact and non-contact methods. Contact on-machine measurement primarily relies on contact probes, while non-contact methods primarily utilize non-contact sensors such as laser probes. While contact on-machine measurement offers high accuracy, it is limited by its single-point touch acquisition mode, and its efficiency cannot meet the requirements for full-scale inspection of industrial parts. With the continuous advancement of industrial technology, non-contact on-machine measurement has become the mainstream development direction, offering advantages such as high speed, simple path planning, and low interference.

[0003] Chinese invention patent publication number CN105404238A discloses a linear calibration method for probe position in on-machine laser measurement. This method uses point structured light in conjunction with a standard five-axis machine tool for on-machine measurement. By fixing the offset and the direction of the point laser's light, the surface of a standard sphere is scanned at multiple angles and the center of the sphere is fitted. However, this calibration method is complex to operate. Limited by the point laser, it can only capture one three-dimensional point at a time. Furthermore, the information contained in a point laser is one dimension less than that of a line laser or a surface laser. Multiple movements of the machine tool are required for multi-angle fitting, resulting in low measurement accuracy and large errors. Therefore, a calibration method for an on-machine measurement system for a non-standard five-axis machine tool is proposed to quickly and accurately establish a calibration relationship between the surface structured light sensor and the non-standard machine tool coordinate system. Summary of the Invention

[0004] In view of this, the present invention proposes an on-machine measurement calibration device and calibration method for a non-standard five-axis machine tool, providing a calibration method for an on-machine measurement system of a non-standard five-axis machine tool with a high degree of automation, which does not require the machine tool to be moved multiple times to obtain three-dimensional data of the calibration device and can simplify the calibration process.

[0005] According to a first aspect of the present invention, the present invention provides an on-machine measurement and calibration device for a non-standard five-axis machine tool, comprising: a spindle, a body, a first reference plane, and a positioning sphere; wherein, The body is arranged facing the spindle of the non-standard five-axis machine tool, and a boss is provided at one end of the body close to the ground, one end of the boss is fixedly connected to the body, and the other end of the boss extends toward the spindle direction of the non-standard five-axis machine tool; The end surface of the body facing the main axis is the first reference plane, the side surface of the body at the non-boss portion is the second reference plane, and the end surface of the boss close to the ground is the third reference plane. The first reference plane, the second reference plane, and the third reference plane are arranged perpendicular to each other. A plurality of positioning balls are arranged on the outer side of the main body close to the main shaft, and a positioning hole is arranged through the main body; the positioning balls are fixedly arranged relative to the main body.

[0006] Preferably, the diameters of the positioning spheres and the distances to the first reference plane are not equal, and the line connecting the center of any positioning sphere and the center of the adjacent positioning sphere or the central axis of the positioning hole is set at an angle to the first reference plane, the second reference plane and the third reference plane.

[0007] Preferably, the positioning sphere and the positioning hole are respectively close to the vertex positions of the first reference plane of the main body, and the first reference plane is perpendicular to the extension direction of the spindle of the non-standard five-axis machine tool; the positioning sphere is arranged on the outside of the spindle of the non-standard five-axis machine tool close to the first reference plane, and is fixed to the first reference plane.

[0008] According to a second aspect of the present invention, a method for calibrating an on-machine measurement of a non-standard five-axis machine tool is provided, which is used for the on-machine measurement calibration device of the non-standard five-axis machine tool described above, comprising the following steps: S1: Set the coordinate system of the non-standard five-axis machine tool and install the tool holder on the spindle of the non-standard five-axis machine tool; S2: Configuring a calibration device, including a first reference plane and a plurality of positioning spheres; S3: Keeping each rotation axis of the non-standard five-axis machine tool unchanged at the initial position, a probe is arranged at the end of the tool holder to obtain a first offset value of the tool holder end relative to the spindle and a second offset value of the probe end relative to the tool holder end; S4: Move the non-standard five-axis machine tool to the calibration device, call the motion geometry calibration cycle instruction, correct the influence of the first offset value and the second offset value, and calculate the three-dimensional coordinate value of the center of the positioning sphere in the coordinate system of the non-standard five-axis machine tool; S5: Remove the probe and install a surface structured light sensor at the end of the tool handle; obtain the three-dimensional coordinate value of the center of the positioning sphere in the coordinate system of the surface structured light sensor through the surface structured light sensor; S6: Solve the three-dimensional coordinate value of the center of the sphere, establish the correspondence between the coordinate system of the surface structured light sensor and the coordinate system of the non-standard five-axis machine tool, calculate the rotation matrix and translation matrix, and complete the calibration process.

[0009] Preferably, in the coordinate system of the non-standard five-axis machine tool, the X, Y, Z and W axes are movable axes, and A, B and C are rotation axes; the horizontal radial direction of the main shaft is the X-axis direction, the vertical upward direction is the Y-axis direction, the horizontal axial direction of the main shaft is the Z-axis direction, and the W axis and the Z axis are arranged in the same direction; the rotation direction along the X axis is the A axis direction, the rotation direction along the Y axis is the B axis direction, and the rotation direction along the Z axis is the C axis direction.

[0010] Preferably, the three-dimensional coordinate value of the center of the positioning sphere in the coordinate system of the non-standard five-axis machine tool is calculated and obtained, including: Through the CNC instruction CYCLE997 and the NC code of the CNC machine tool, the non-standard five-axis machine tool main shaft is moved so that the probe extended on the main shaft is against the surface of the positioning sphere. The four-point method based on Cramer's law is performed on each positioning sphere to obtain the three-dimensional coordinates of the center of each positioning sphere in the XYZWABC coordinate system of the non-standard five-axis machine tool.

[0011] Preferably, the removing the probe and installing the surface structured light sensor at the end of the handle comprises: After removing the probe, the tool holder is retained, and a surface structured light sensor is installed at the end of the tool holder. The spindle of the non-standard five-axis machine tool is moved so that several positioning spheres are all within the field of view of the surface structured light sensor. The projector of the surface structured light sensor projects a stripe grating onto the surface of the calibration device. The cameras on both sides of the surface structured light sensor synchronously capture the image of the stripe grating, analyze the phase constraints of the stripe grating image and the epipolar constraints between the cameras, determine the depth information of each pixel point, and complete the three-dimensional reconstruction of the calibration device.

[0012] Preferably, the step of obtaining the three-dimensional coordinate value of the center of the positioning sphere in the coordinate system where the surface structured light sensor is located by using the surface structured light sensor includes: The sphere center fitting formula in space is used to solve the 3D coordinates of the sphere center; The distance from the point to be fitted to the sphere is used as the cost function to construct a residual calculation model: Solve the result that meets the conditions and calculate the coordinates of the center of the sphere.

[0013] Preferably, the process of obtaining the three-dimensional coordinate value of the center of the positioning sphere in the coordinate system of the surface structured light sensor by the surface structured light sensor further includes: initial data segmentation and final data segmentation; wherein, The initial data segmentation uses Euclidean distance clustering, which includes: searching for neighboring points for a certain point P in the image point cloud, setting a distance pre-threshold, and clustering all point clouds with a distance less than the threshold into a set Q. If the number of elements in Q does not increase, the clustering process ends; otherwise, select points other than P and search for neighboring points again and add them to the set Q until the number of elements in the set Q does not increase. The final data segmentation is based on a percentage segmentation method, a maximum segmentation ratio and a minimum segmentation ratio are set, and the final set after screening is set within the range of the maximum segmentation ratio and the minimum segmentation ratio.

[0014] Preferably, the process of solving the three-dimensional coordinate value of the sphere center, establishing the correspondence between the coordinate system of the surface structured light sensor and the coordinate system of the non-standard five-axis machine tool, and calculating the rotation matrix and the translation matrix to complete the calibration process includes: Ignoring the A, B, C, and W axes of the XYZWABC coordinate system of the non-standard five-axis machine tool, the conversion relationship between the non-standard five-axis machine tool and the coordinate system of the surface structured light sensor is established, as shown below;

[0015] Among them, x Mj 、y Mj 、z Mj Represents the machine tool coordinates, X cj 、Y cj 、Z cj Represent visual coordinates respectively; is the first offset value of the tool holder end relative to the spindle, is the second offset value of the probe end relative to the tool holder end, and It is the rotation matrix and translation matrix between the coordinate system of the surface structured light sensor and the coordinate system of the non-standard five-axis machine tool.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides an on-machine measurement calibration device and calibration method for a non-standard five-axis machine tool, provides a calibration process for on-machine measurement of a non-standard five-axis machine tool, realizes the conversion relationship between the surface result light sensor and the machine tool coordinate system, and aims to solve the problems existing in the existing on-machine measurement, such as inaccurate calibration accuracy, complex calibration process, and no available mathematical model for application in the calibration of non-standard five-axis machine tools and surface structure light sensors in this system. Only a single measurement of the surface result light sensor on the calibration device combined with four-point measurement of the probe is required to realize the feature point positioning and calibration process. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 A schematic structural diagram of an on-machine measurement and calibration device for a non-standard five-axis machine tool provided by an embodiment of the present invention; Figure 2 A three-dimensional diagram of the combined state of the spindle and the surface structured light sensor of an on-machine measurement and calibration device for a non-standard five-axis machine tool provided by an embodiment of the present invention; Figure 3 A three-dimensional diagram of an on-machine measurement and calibration device for a non-standard five-axis machine tool provided in an embodiment of the present invention.

[0019] Figure numerals: 1. spindle; 2. calibration device; 20. body; 21. positioning sphere; 22. positioning hole; 23. first reference plane; 24. second reference plane; 25. third reference plane; 100. boss; 3. surface structured light sensor. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] An embodiment of the present invention provides an on-machine measurement and calibration device for a non-standard five-axis machine tool, comprising: a body 20, a first reference plane 23, and a plurality of positioning spheres 21; wherein the first reference plane 23 of the calibration device 2 is perpendicular to the extension direction of the spindle 1 of the non-standard five-axis machine tool; the plurality of positioning spheres 21 are arranged on the outside of the first reference plane 23 near the spindle 1 of the non-standard five-axis machine tool, and are fixed relative to the first reference plane 23; like Figures 1 to 3 As shown, the main body 20 is arranged facing the spindle 1 of the non-standard five-axis machine tool, and a boss 100 is provided at one end of the main body 20 close to the ground. One end of the boss 100 is fixedly connected to the main body 20, and the other end of the boss 100 also extends toward the spindle 1 of the non-standard five-axis machine tool; the end face of the main body 20 facing the spindle 1 is a first reference plane 23, the side surface of the main body 20 where the boss 100 is not located is a second reference plane 24, and the end face of the boss 100 close to the ground is a third reference plane 25. The first reference plane 23, the second reference plane 24 and the third reference plane 25 are arranged perpendicular to each other; three positioning balls 21 are provided on the outer side of the main body 20 close to the spindle 1, and a positioning hole 22 is provided through the main body 20; the three positioning balls 21 are fixedly arranged relative to the main body 20. Figure 1 To ensure that the first reference plane 23 is aligned with the spindle 1, a base is often further provided below the boss 100 to raise the height of the calibration device 2. When the calibration device 2 is placed, one end of the boss 100 is positioned close to the bottom surface, and the body 20 extends vertically upward in the vertical direction. To ensure that the third reference plane 25 is horizontal, a base can be provided between the base and the third reference plane. The diameters of the three positioning spheres 21 and the distances to the first reference plane 23 are not equal to each other. The line connecting the center of any positioning sphere 21 and the center of the adjacent positioning sphere 21 or the central axis of the positioning hole 22 is set at an angle to the first reference plane 23, the second reference plane 24 and the third reference plane 25.

[0022] Three positioning spheres 21 and positioning holes 22 are respectively arranged near the vertex positions of the first reference plane 23 of the body 20; the diameter of the positioning sphere 21 is not greater than 52 mm; and the diameter of the positioning hole 22 is 30 mm. The surface of the three positioning spheres 21 is supported and fixed by the support rod and the body 20. The distribution mode of the positioning spheres is to ensure that any internal angle of the triangle formed by the sphere centers is not less than 15°, and is as uniformly distributed as possible, which is beneficial to improve the measurement accuracy.

[0023] Additionally, the embodiment of the present application further provides a calibration method of an on-machine measurement system of a non-standard five-axis machine tool, which is applied to the on-machine measurement calibration device of the non-standard five-axis machine tool. S1: setting an XYZWABC coordinate system of the non-standard five-axis machine tool, and installing a tool holder on the main shaft 1 of the non-standard five-axis machine tool; the tool holder is arranged in an axial extension mode along the main shaft; In the present embodiment step, the XYZWABC coordinate system of the non-standard five-axis machine tool is set, that is, the X, Y, Z and W axes are moving axes, and the A, B and C axes are rotating axes; the horizontal radial direction of the main shaft 1 is the X axis direction, the vertical upward direction is the Y axis direction, the axial direction of the horizontal extension of the main shaft 1 is the Z axis direction, and the W axis is arranged in the same direction as the Z axis; the rotating direction along the X axis is the A axis direction, the rotating direction along the Y axis is the B axis direction, and the rotating direction along the Z axis is the C axis direction. The B axis is the rotating shaft of the rotary table of the machine tool, and the B axis is kept unchanged at the initial position in the present application. The counterclockwise direction of the rotating axes A, B and C is the positive rotating direction, and the clockwise direction is the reverse rotating direction.

[0024] S2: configuring the calibration device 2; the calibration device 2 comprises a first reference plane 23 and a plurality of positioning spheres 21; wherein the first reference plane 23 of the calibration device 2 is perpendicular to the extension direction of the main shaft 1 of the non-standard five-axis machine tool; the plurality of positioning spheres 21 are arranged on the outer side of the first reference plane 23 close to the main shaft 1 of the non-standard five-axis machine tool, and are fixedly arranged opposite to the first reference plane 23; S3: keeping the rotating axes of the non-standard five-axis machine tool unchanged at the initial position, and keeping the W axis unchanged at a fixed value; configuring a probe at the end of the tool holder, and respectively acquiring a first offset value of the tool holder end relative to the main shaft 1 and a second offset value of the probe end relative to the tool holder end; Let the first offset value of the tool holder end relative to the main shaft 1 be , and the second offset value of the probe end relative to the tool holder end be .

[0025] S4: moving the non-standard five-axis machine tool to the vicinity of the calibration device 2, calling a motion geometry calibration cycle instruction, correcting the influence of the first offset value and the second offset value according to the four-point method, and calculating the three-dimensional coordinate values of the sphere centers of the plurality of positioning spheres 21 under the XYZWABC coordinate system of the non-standard five-axis machine tool; In this implementation step, the non-standard five-axis machine tool spindle 1 is moved through the CNC instruction CYCLE997 and the CNC machine tool NC code, so that the probe extending from the spindle 1 is in contact with the surface of the positioning sphere 21, and each positioning sphere 21 is measured by the four-point method based on Cramer's law to obtain the three-dimensional coordinates of the center of each positioning sphere 21 in the XYZWABC coordinate system of the non-standard five-axis machine tool.

[0026] , .

[0027] Where, P mj Expressed as the coordinate of the sphere center in the machine tool coordinate system; X Mj 、Y Mj , Z Mj They represent the three-dimensional coordinates of the sphere center in the machine tool coordinate system; J represents the positioning ball number.

[0028] The coordinates of the centers of the three positioning spheres in the XYZWABC coordinate system of the non-standard five-axis machine tool are obtained for the first time through the command. The measuring points can be given as arcs along the surfaces of the positioning spheres.

[0029] S5: Remove the probe and install a surface structured light sensor 3 at the end of the tool handle; obtain the three-dimensional coordinate values ​​of the centers of the positioning spheres 21 in the coordinate system of the surface structured light sensor again through the surface structured light sensor 3; In this embodiment, removing the probe and installing the surface structured light sensor 3 at the end of the tool handle specifically includes: after removing the probe, retaining the tool handle, installing the surface structured light sensor 3 at the end of the tool handle, moving the non-standard five-axis machine tool spindle 1 so that the plurality of positioning spheres 21 are all within the field of view of the surface structured light sensor 3; the projector of the surface structured light sensor 3 projects a fringe grating onto the surface of the calibration device 2; the left and right cameras of the surface structured light sensor 3 synchronously capture images of the fringe grating, and by analyzing the phase constraints of the fringe grating image and the epipolar constraints between the cameras, the depth information of each pixel is determined, thereby completing the three-dimensional reconstruction of the calibration device 2. Subsequently, the fringe grating will be distorted when it lands on the positioning sphere or positioning hole, which has a different radius than the positioning sphere 21 and is convex, and the positioning hole is concave. The three axial directions of the coordinate system of the surface structured light sensor can be parallel to the three axial directions of the non-standard five-axis machine tool (X, Y, and Z), or of course, the axial directions can be redefined. By analyzing the distorted form of the fringe grating, the depth of the corresponding pixel or the height in the Z direction is obtained.

[0030] Assuming that the image of the fringe grating is a standard sinusoidal image, the total number of phase-shifted images of the fringe grating is N , No. n Light intensity distribution function of the phase-shifted image of a fringe grating for: ,in is the background light intensity, is the modulation depth of the fringes, is the phase shift of the image, is the phase difference: Through the principle of multi-frequency heterodyne, the phase difference value of the left and right cameras of the surface structured light sensor 3 for the same pixel is expanded into a continuously changing absolute phase value , according to the formula Calculate the depth of a pixel, where 、 and These are the parameters determined during the initial self-calibration of the surface structured light sensor 3 and the stripe grating encoding, and the three-dimensional information of each pixel is obtained.

[0031] The process of obtaining the three-dimensional coordinates of the center of the positioning sphere 21 in the coordinate system of the surface structured light sensor 3 by the surface structured light sensor specifically includes: The sphere center fitting formula in space is used to solve the sphere center's three-dimensional coordinates; the sphere center fitting formula in space is expressed as: ; Where, For the final set The points to be fitted in; is the coordinate of the center of the fitted sphere; is the radius of the fitted sphere center.

[0032] The distance from the point to be fitted to the sphere is used as the cost function to construct a residual calculation model: In order to ensure that the position of the fitted sphere center meets the requirements, the distance from the point to be fitted to the sphere surface is used as the cost function to construct a residual calculation model: , By solving the The result of the conditions is to calculate the coordinates of the center of the sphere .

[0033] This is a robust kernel function that directly optimizes model parameters. It artificially reduces the weights of points that do not conform to the sphere center's coordinates, minimizing the impact of erroneous data on the residual calculation. When the residual is small, the original cost function remains unchanged. The coordinates of the sphere center can be obtained using the QR decomposition method. This method is a common technique in this field and will not be discussed further here.

[0034] In order to screen the pixels and reduce the scale of subsequent fitting calculations, step S5 also includes: initial data segmentation and final data segmentation; wherein, The initial data segmentation adopts Euclidean distance clustering. The criterion of Euclidean distance clustering is based on the resolution of the image point cloud. For a certain point P in the image point cloud, the nearest neighbor points are searched, and a distance pre-threshold is set. The point clouds with a distance less than the distance threshold are clustered into a set Q. If the number of elements in Q does not increase, the clustering process ends; otherwise, points other than P are selected to search for nearest neighbor points again and added to the set Q until the number of elements in the set Q does not increase. Among them, the distance threshold , is the point cloud resolution, , is the number of all elements in the set Q, is any element in the set Q, For all corresponding Neighboring points; After the initial data segmentation step, the image point cloud is divided into several sets Q. Further final data segmentation is required, including: using a percentage-based segmentation method, setting the maximum and minimum segmentation ratios, and meeting the following criteria:

[0035] in, is the minimum split ratio, is the maximum split ratio, This is the final set after filtering.

[0036] S6: By solving the three-dimensional coordinate values ​​of the sphere center twice, the corresponding relationship between the coordinate system of the surface structured light sensor 3 and the coordinate system of the non-standard five-axis machine tool is established, the rotation matrix and the translation matrix are calculated, and the calibration process is completed.

[0037] In this implementation step, the A, B, C, and W axes of the XYZWABC coordinate system of the non-standard five-axis machine tool are ignored, and the conversion relationship between the non-standard five-axis machine tool and the coordinate system of the surface structured light sensor 3 is established:

[0038] in, and is the rotation matrix and translation matrix between the coordinate system of the surface structured light sensor 3 and the coordinate system of the non-standard five-axis machine tool. Since the XYZWABC coordinate system of the non-standard five-axis machine tool is simplified to a three-axis coordinate system, it has the same dimension as the coordinate system of the surface structured light sensor 3. and It has been obtained in advance, and the rotation matrix and translation matrix are obtained by calculation, so as to obtain the calibration relationship between the coordinate system of the surface structured light sensor 3 and the coordinate system of the non-standard five-axis machine tool.

[0039] Solving the rotation matrix The SVD decomposition method can be used, which is a conventional technique in the art and will not be described here.

[0040] The following is a verification process of the scheme of the embodiment of the application, the calibration process can be completed in a short time, and the cumbersome calibration process of the non-standard five-axis machine tool in-machine measurement system is solved.

[0041] The coordinates of the ball center in the non-standard five-axis machine tool coordinate system obtained by calibration are: Table 1 Ball center coordinates in the non-standard five-axis machine tool coordinate system

[0042] Table 2 Ball center coordinates in the coordinate system of the surface structure light sensor

[0043] The first offset value is: The second offset value is: ; The rotation matrix obtained by calculation is: The translation matrix obtained by calculation is: .

[0044] In summary, the embodiment of the application provides a calibration process of in-machine measurement of a non-standard five-axis machine tool, realizes the conversion relationship between the surface structure light sensor and the machine tool coordinate system, and aims to solve the problems in the prior art, such as inaccurate calibration accuracy, complex calibration process, and no available mathematical model applied in the calibration of the non-standard five-axis machine tool and the surface structure light sensor, and only one-time measurement of the calibration device by the surface structure light sensor and four-point measurement by the probe can realize feature point positioning and the calibration process.

[0045] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application fall within the scope of the claims of the application and their equivalents, the application also intends to include these modifications and variations.

[0046] Finally, it should be noted that: the above only describes the preferred embodiments of the application, and is not intended to limit the application, although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some technical features, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. An on-machine measurement and calibration device for a non-standard five-axis machine tool, characterized in that: include: A main shaft (1), a main body (20), a first reference plane (23) and a positioning sphere (21); wherein, The body (20) is arranged facing the main shaft (1) of the non-standard five-axis machine tool, and a boss (100) is provided at one end of the body (20) close to the ground, one end of the boss (100) is fixedly connected to the body (20), and the other end of the boss (100) extends toward the main shaft (1) of the non-standard five-axis machine tool; The end surface of the body (20) facing the main shaft (1) is a first reference plane (23), the side surface of the body (20) at a position other than the boss (100) is a second reference plane (24), and the end surface of the boss (100) close to the ground is a third reference plane (25); the first reference plane (23), the second reference plane (24), and the third reference plane (25) are arranged perpendicular to each other; A plurality of positioning balls (21) are provided on the outer side of the main body (20) close to the main shaft (1), a positioning hole (22) is provided through the main body (20), and the positioning balls (21) are fixed to the main body (20).

2. The on-machine measurement and calibration device for a non-standard five-axis machine tool according to claim 1, characterized in that: The diameters of the positioning spheres (21) and the distances to the first reference plane (23) are not equal to each other, and the line connecting the center of any positioning sphere (21) and the center of an adjacent positioning sphere (21) or the central axis of the positioning hole (22) is set at an angle to the first reference plane (23), the second reference plane (24) and the third reference plane (25).

3. The on-machine measurement and calibration device for a non-standard five-axis machine tool according to claim 1, characterized in that: The positioning sphere (21) and the positioning hole (22) are respectively close to the vertex positions of the first reference plane (23) of the body (20), and the first reference plane (23) is perpendicular to the extension direction of the main shaft (1) of the non-standard five-axis machine tool; the positioning sphere (21) is arranged on the first reference plane (23) close to the outside of the main shaft (1) of the non-standard five-axis machine tool, and is fixed to the first reference plane (23).

4. An on-machine measurement and calibration method for a non-standard five-axis machine tool, used for an on-machine measurement and calibration device for a non-standard five-axis machine tool according to any one of claims 1 to 3, characterized in that: The calibration comprises the following steps: S1: Set the coordinate system of the non-standard five-axis machine tool and install the tool holder on the spindle (1) of the non-standard five-axis machine tool; S2: Configuring a calibration device (2); comprising a first reference plane (23) and a plurality of positioning spheres (21); S3: Keeping the various rotation axes of the non-standard five-axis machine tool unchanged at their initial positions, arranging a probe at the end of the tool holder, and obtaining a first offset value of the tool holder end relative to the spindle (1) and a second offset value of the probe end relative to the tool holder end; S4: Move the non-standard five-axis machine tool to the side of the calibration device (2), call the motion geometry calibration cycle instruction, correct the influence of the first offset value and the second offset value, and calculate the three-dimensional coordinate value of the center of the positioning sphere (21) in the coordinate system of the non-standard five-axis machine tool; S5: Remove the probe and install a surface structured light sensor (3) at the end of the tool handle; obtain the three-dimensional coordinate value of the center of the positioning sphere (21) in the coordinate system where the surface structured light sensor is located through the surface structured light sensor (3); S6: Solve the three-dimensional coordinate value of the center of the sphere, establish the corresponding relationship between the coordinate system of the surface structured light sensor (3) and the coordinate system of the non-standard five-axis machine tool, calculate the rotation matrix and translation matrix, and complete the calibration process.

5. The on-machine measurement and calibration method for a non-standard five-axis machine tool according to claim 4, characterized in that: In the coordinate system of the non-standard five-axis machine tool, the X, Y, Z and W axes are movable axes, and A, B and C are rotation axes; the horizontal radial direction of the main shaft (1) is the X-axis direction, the vertical upward direction is the Y-axis direction, the horizontal axial direction of the main shaft (1) is the Z-axis direction, and the W axis and the Z axis are arranged in the same direction; the rotation direction along the X axis is the A axis direction, the rotation direction along the Y axis is the B axis direction, and the rotation direction along the Z axis is the C axis direction.

6. The on-machine measurement and calibration method for a non-standard five-axis machine tool according to claim 4, characterized in that: The three-dimensional coordinate values ​​of the center of the positioning sphere (21) in the coordinate system of the non-standard five-axis machine tool are calculated and obtained, including: By using the numerical control instruction CYCLE997 and the numerical control machine tool NC code, the non-standard five-axis machine tool spindle (1) is moved so that the probe extending from the spindle (1) is in contact with the surface of the positioning sphere (21), and each positioning sphere (21) is measured using the four-point method based on Cramer's law to obtain the three-dimensional coordinates of the center of each positioning sphere in the XYZWABC coordinate system of the non-standard five-axis machine tool.

7. The on-machine measurement and calibration method for a non-standard five-axis machine tool according to claim 4, characterized in that: The probe is removed and a surface structured light sensor (3) is installed at the end of the tool handle, including: After removing the probe, the tool handle is retained, and a surface structured light sensor (3) is installed at the end of the tool handle. The non-standard five-axis machine tool spindle (1) is moved so that the plurality of positioning spheres (21) are all located within the field of view of the surface structured light sensor (3); the projector of the surface structured light sensor (3) projects a stripe grating onto the surface of the calibration device (2); the cameras on both sides of the surface structured light sensor (3) synchronously capture an image of the stripe grating, analyze the phase constraint of the image of the stripe grating and the polar constraint between the cameras, determine the depth information of each pixel point, and complete the three-dimensional reconstruction of the calibration device (2).

8. The on-machine measurement and calibration method for a non-standard five-axis machine tool according to claim 4, characterized in that: The method of obtaining the three-dimensional coordinate values ​​of the center of the positioning sphere (21) in the coordinate system where the surface structured light sensor is located by the surface structured light sensor (3) includes: The sphere center fitting formula in space is used to solve the 3D coordinates of the sphere center; The distance from the point to be fitted to the sphere is used as the cost function to construct a residual calculation model: Solve the result that meets the conditions and calculate the coordinates of the center of the sphere.

9. The on-machine measurement and calibration method for a non-standard five-axis machine tool according to claim 4, characterized in that: The method of obtaining the three-dimensional coordinate value of the center of the positioning sphere (21) in the coordinate system of the surface structured light sensor (3) further includes: initial data segmentation and final data segmentation; wherein, The initial data segmentation adopts Euclidean distance clustering, which includes: searching for neighboring points for a certain point P in the image point cloud, setting a distance pre-threshold, and clustering all point clouds with a distance less than the distance threshold into a set Q. If the number of elements in Q does not increase, the clustering process ends; otherwise, selecting points other than P and re-searching for neighboring points and adding them to the set Q until the number of elements in the set Q does not increase. The final data segmentation is based on a percentage segmentation method, a maximum segmentation ratio and a minimum segmentation ratio are set, and the final set after screening is set within the range of the maximum segmentation ratio and the minimum segmentation ratio.

10. The on-machine measurement and calibration method for a non-standard five-axis machine tool according to claim 4, characterized in that: The three-dimensional coordinate value of the center of the sphere is solved, the corresponding relationship between the coordinate system of the surface structured light sensor (3) and the coordinate system of the non-standard five-axis machine tool is established, the rotation matrix and the translation matrix are obtained, and the calibration process is completed, including: Ignoring the A, B, C and W axes of the XYZWABC coordinate system of the non-standard five-axis machine tool, the conversion relationship between the non-standard five-axis machine tool and the coordinate system where the surface structured light sensor (3) is located is established, which is expressed as follows; Among them, x Mj 、y Mj 、z Mj Represents the machine tool coordinates, X cj 、Y cj , Z cj Represent visual coordinates respectively; is the first offset value of the tool holder end relative to the spindle (1), is the second offset value of the probe end relative to the tool holder end, and are the rotation matrix and translation matrix between the coordinate system of the surface structured light sensor (3) and the coordinate system of the non-standard five-axis machine tool.

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