Calibration device of on-machine measurement system

Abstract

The utility model discloses a calibration device of an on-machine measurement system, which belongs to the technical field of three-dimensional measurement, and comprises a base, the top end of the base is fixedly connected with a supporting base, the top end of the supporting base is bolted with a fixing frame, the top end of the fixing frame is provided with a scanner calibration plate, the inner cavity of the fixing frame is provided with a calibration block, and the inner cavity of the fixing frame is provided with the scanner calibration plate. The bottom end of the calibration block is fixedly connected with a calibration base, the bottom end of the calibration base is provided with an adjusting structure used for adjusting the height of the calibration block, the surface of the calibration block is provided with a round hole, the surface of the calibration block is further provided with three sets of calibration balls, and the heights of the three sets of calibration balls are different. The calibration block is provided with three groups of planes which are perpendicular to one another, and the three groups of planes are respectively a first reference plane, a second reference plane and a third reference plane, so that the calibration precision is improved, and the calibration process is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of three-dimensional measurement, in particular to a calibration device for an on-machine measurement system. Background Art

[0002] Optical measurement has a wide range of applications in aerospace, reverse engineering, reality, industrial automatic inspection, cultural and creative fields, product quality control, automotive, and other fields. With the continuous development of industrial measurement and CNC technology, more and more on-machine measurement technologies that combine sensors with machining centers are being used. On-machine measurement technologies can be divided into contact and non-contact types. Contact mainly relies on contact probes to touch the object, while non-contact currently mainly uses point structured light or line structured light for detection. At the same time, this method is mainly combined with standard three-axis or higher machine tools for execution.

[0003] The solution with publication number: CN114061459A provides a calibration device and method for non-contact photogrammetry. The device includes a base, a mounting platform, a calibration component, and an illumination compensator. The mounting platform is arranged on the base, and the calibration component is arranged on the mounting platform. During the calibration process, the base drives the mounting platform to rotate about the Z axis, thereby driving the calibration component to rotate about the Z axis. The mounting platform simultaneously drives the calibration component to rotate about the X axis. The illumination compensator is used to provide fill light to the camera during the camera shooting process. The camera system analyzes and calculates the images of the obtained projections of the circular contours of several calibration spheres, thereby ultimately achieving calibration of the connection hole.

[0004] The calibration device described above presents challenges in calibrating standard machine tools with more than three axes and point lasers or line structured light systems, including inaccurate calibration accuracy and a complex calibration process caused by the extensive computational effort and instability of the nonlinear optimization solution. Furthermore, the simple structure of the calibration device and the limited reference information it provides make the calibration process cumbersome. Therefore, a calibration device for on-machine measurement systems is needed. Utility Model Content

[0005] The purpose of the utility model is to provide a calibration device for an on-machine measurement system, which is used to simultaneously provide information of multiple dimensions such as verticality and flatness benchmarks, thereby simplifying the calibration process.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a calibration device for an on-machine measurement system, comprising:

[0007] base;

[0008] A support base is provided at an end of the base away from the bottom surface and is fixedly connected to the base;

[0009] A fixing frame, fixedly arranged on an end of the support base away from the ground;

[0010] A scanner calibration plate is arranged at an end of the fixing frame away from the bottom surface;

[0011] The calibration block is arranged at a non-end position of the fixing frame; the position of the calibration block relative to the fixing frame is adjustable.

[0012] Preferably, the calibration block includes a body and a boss, a boss is provided at one end of the body close to the ground, and the boss is connected to the fixing frame; a first reference plane is provided on the body, the side surface of the body on the non-boss side is a second reference plane, and the end surface of the boss close to the fixing frame is a third reference plane; the first reference plane, the second reference plane and the third reference plane are perpendicular to each other; a through circular hole is provided on the body; a plurality of calibration balls are also provided on the outside of the calibration block, and some of the calibration balls are fixed relative to the body; the radii of some of the calibration balls and the distances from the calibration balls to the first reference plane are not equal to each other.

[0013] Preferably, there are three groups of the calibration balls, which are fixedly connected to the first reference plane of the main body through connecting rods; the projections of the calibration balls on the first reference plane and the circular holes are respectively arranged close to different vertices of the main body.

[0014] Preferably, the centers of the three groups of calibration spheres form a virtual triangle, and any internal angle of the virtual triangle is not less than 15°.

[0015] Preferably, a calibration base and an adjustment structure are provided between the calibration block and the fixing frame; the adjustment structure includes a support plate, the support plate is located inside the fixing frame, a first threaded hole is provided at the end of the support plate, an adjustment slot is provided on the fixing frame, the support plate is fixedly connected to the adjustment slot by bolts, a mounting plate is provided on the outer side of the support plate, the top of the mounting plate is fixedly connected to the bottom end of the calibration base, and the calibration base is used to place the calibration block; the adjustment structure is used to change the position of the calibration base and the calibration block on the fixing frame.

[0016] Preferably, the mounting plate is L-shaped, and a second threaded hole is provided on the surface of the mounting plate. The second threaded hole is fixedly connected to the adjustment slot and the support plate respectively through bolts.

[0017] Preferably, a reinforcing block is provided on the inner side wall of the mounting plate, both ends of the reinforcing block are fixedly connected to the surface of the mounting plate, the reinforcing block is triangular in shape, and several groups of the reinforcing blocks are provided.

[0018] Preferably, the inner cavity of the fixing frame is provided with support columns, and the support columns are provided in two groups, and the adjacent ends of the two groups of support columns are arranged at an angle.

[0019] Preferably, a reinforcing plate is provided at the bottom end of the base, and the cross-sectional size of the reinforcing plate is inversely proportional to the height from the ground.

[0020] Preferably, a reinforcing rod is provided on the base, and the base includes a plurality of columns, which are arranged in a rectangular array and extend along the vertical direction; the two ends of the reinforcing rod are respectively fixedly connected to the surfaces of two different columns, and the end of the reinforcing rod is arranged at an inclined angle to the column.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This utility model provides a calibration device for an on-machine measurement system. Three calibration spheres are provided, and their center coordinates are acquired through blue light scanning. Precision-machined circular holes serve as the center of the local workpiece coordinate system. The first datum plane is perpendicular to the machine tool's Z axis and is also mutually perpendicular to the second and third datum planes. Machining ensures perpendicularity and flatness accuracy, providing reliable calibration information and simplifying the calibration process.

[0023] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be achieved and obtained by the structures indicated in the description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the utility model from a side view;

[0026] Figure 3 This is a schematic diagram of the structure of the adjustment structure and calibration block of the utility model;

[0027] Figure 4 This is a structural diagram of the calibration block of the utility model.

[0028] In the figure: 1. Base; 2. Support base; 3. Fixing bracket; 4. Scanner calibration plate; 5. Calibration block; 6. Calibration base; 7. Adjustment structure; 71. Support plate; 72. First threaded hole; 73. Adjustment slot; 74. Mounting plate; 8. Round hole; 9. Calibration ball; 10. First reference plane; 11. Second reference plane; 12. Third reference plane; 13. Second threaded hole; 14. Reinforcement block; 15. Support column; 16. Reinforcement plate; 17. Mounting block; 18. Reinforcement rod. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in 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.

[0030] See also Figure 1-4 The present invention provides a technical solution: a calibration device for an on-machine measurement system, comprising: a base 1; a support base 2, disposed at an end of the base 1 away from the bottom surface and fixedly connected to the base 1; a fixing frame 3, fixedly disposed at an end of the support base 2 away from the surface; and a scanner calibration plate 4, disposed at an end of the fixing frame 3 away from the bottom surface. A calibration block 5 is disposed at a non-end position of the fixing frame 3; and the position of the calibration block 5 relative to the fixing frame 3 is adjustable.

[0031] In this embodiment, the calibration block 5 includes a body and a boss. The boss is provided at one end of the body close to the ground, and the boss is connected to the fixing frame 3 .

[0032] In a further preferred embodiment of the present invention, a first reference plane 10 is provided on the main body, the side surface of the main body on the non-boss side is a second reference plane 11, and the end surface of the boss close to the fixing frame 3 is a third reference plane 12; the first reference plane 10, the second reference plane 11 and the third reference plane 12 are perpendicular to each other.

[0033] The body is provided with a through circular hole 8; the outer side of the calibration block 5 is also provided with a plurality of calibration balls 9, which are fixed relative to the body; the radius of the plurality of calibration balls 9 and the distance from the calibration ball 9 to the first reference plane 10 are not equal.

[0034] Furthermore, there are three groups of calibration balls 9, and the three groups of calibration balls 9 are fixedly connected to the first reference plane 11 of the main body through a connecting rod; the projections of the calibration balls 9 on the first reference plane 11 and the circular hole 8 are respectively arranged near different vertices of the main body; the centers of the three groups of calibration balls 9 form a virtual triangle, and any internal angle of the virtual triangle is not less than 15°;

[0035] During calibration, the coordinates of the sphere centers of the three calibration spheres 9 are acquired through blue light scanning. The circular hole 8 is precisely machined to serve as the center of the local workpiece coordinate system. The first datum plane 10 is perpendicular to the machine's Z axis and mutually perpendicular to the second and third datum planes 11 and 12. Machining ensures perpendicularity and flatness, improving calibration accuracy and simplifying the process.

[0036] In this embodiment, a calibration base 6 and an adjustment structure 7 are provided between the calibration block and the fixing frame.

[0037] Specifically, the adjustment structure 7 includes a support plate 71, which is located inside the fixing frame 3. A first threaded hole 72 is provided at the end of the support plate 71, and an adjustment slot 73 is provided on the fixing frame 3. The support plate 71 is fixedly connected to the adjustment slot 73 by bolts. A mounting plate 74 is provided on the outer side of the support plate 71. The top of the mounting plate 74 is fixedly connected to the bottom end of the calibration base 6, and the calibration base 6 is used to place the calibration block 5.

[0038] The adjustment structure 7 is used to change the position of the calibration base 6 and the calibration block 5 on the fixing frame 3. Loosen the bolts to cancel the positioning between the calibration base 6 and the inner cavity of the adjustment groove 73, and push the support plate 71 to move in the inner cavity of the fixing frame 3. After adjusting the position, tighten the bolts to position the position in the adjustment groove 73, so that the position of the calibration block 5 on the support plate 71 can be adjusted.

[0039] In this embodiment, the mounting plate 74 is L-shaped, and a second threaded hole 13 is provided on the surface of the mounting plate 74. The second threaded hole 13 is fixedly connected to the adjustment groove 73 and the support plate 71 by bolts respectively. Through the setting of the mounting plate 74, the support plate 71 can be assisted in positioning on the fixing frame 3, thereby assisting in increasing the supporting force of the calibration block 5 and improving the stability of the calibration block 5.

[0040] Preferably, a reinforcing block 14 is provided on the inner side wall of the mounting plate 74, and both ends of the reinforcing block 14 are fixedly connected to the surface of the mounting plate 74. The reinforcing block 14 is triangular in shape, and several groups of reinforcing blocks 14 are provided. Through the setting of the reinforcing blocks 14, the inner cavity of the mounting plate 74 is supported to prevent the mounting plate 74 from being deformed due to long-term use.

[0041] Furthermore, the inner cavity of the fixing frame 3 is provided with support columns 15, and there are two groups of support columns 15. The adjacent ends of the two groups of support columns 15 are set at an angle. Through the setting of the support columns 15, the bottom end of the fixing frame 3 is reinforced, thereby improving the stability of the fixing frame 3.

[0042] In addition, a reinforcing plate 16 is provided at the bottom end of the base 1. The cross-sectional dimensions of the reinforcing plate 16 are inversely proportional to the height from the ground. The provision of the reinforcing plate 16 supports the bottom end of the base 1 and enhances the stability of the bottom end of the base 1. The reinforcing plate 16 acts like a reinforcing rib, which can improve the overall strength of the base 1.

[0043] In a further preferred embodiment of the present invention, mounting blocks 17 are fixedly connected on both sides of the base 1, and lifting rings are provided on the surface of the mounting blocks 17. There are two groups of mounting blocks 17. Through the provision of lifting rings, it is convenient for a crane to lift the calibration device during transfer, thereby providing convenience for the transfer of the calibration device.

[0044] In addition, a reinforcing rod 18 is provided on the base 1, and the base 1 includes a plurality of columns, which are arranged in a rectangular array and extend along the vertical direction; the two ends of the reinforcing rod 18 are respectively fixedly connected to the surfaces of two different columns, and the end of the reinforcing rod 18 is set at an inclined angle to the column. Through the setting of the reinforcing rod 18, the interior of the base 1 is supported and the stability of the base 1 is reinforced.

[0045] During specific use: During calibration, the three calibration balls 9 can obtain the coordinates of the sphere center through blue light surface scanning. Three-dimensional blue light scanning to obtain the coordinates of the sphere center is a common technical means in this field. The present invention does not involve technical improvements to blue light scanning, but only uses existing equipment to achieve this function. The circular hole 8 is precisely machined and serves as the center of the local workpiece coordinate system. The first reference plane 10 is perpendicular to the Z axis of the machine tool, and is also perpendicular to the second reference plane 11 and the third reference plane 12. The verticality and flatness accuracy are ensured through machining. The blue light surface structured light 3D scanner is fixed to the end of the machine tool. According to the preset program, the machine tool drives the scanner to the calibration point, triggering a single measurement. The calibration process is completed by combining the pre-obtained coordinates of the sphere center in the machine tool coordinate system. The whole process takes a very short time and is easy to operate. The calibration can be completed in one time without moving the machine tool multiple times. It has been verified in practice that the calibration accuracy is high and the efficiency is high, meeting the actual needs of the on-machine measurement system, thereby improving the calibration accuracy and simplifying the calibration process.

[0046] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A calibration device for an on-machine measurement system, characterized in that: include: Base (1); A support base (2) is arranged at an end of the base (1) away from the bottom surface and is fixedly connected to the base (1); A fixing frame (3) is fixedly arranged on an end of the support base (2) away from the ground; A scanner calibration plate (4) is arranged at an end of the fixing frame (3) away from the bottom surface; A calibration block (5) is arranged at a non-end position of the fixing frame (3); the position of the calibration block (5) relative to the fixing frame (3) is adjustable; The calibration block (5) comprises a body and a boss, wherein the boss is provided at one end of the body close to the ground, and the boss is connected to the fixing frame (3); a first reference plane (10) is provided on the body, a side surface of the body on the non-boss side is a second reference plane (11), and an end surface of the boss close to the fixing frame (3) is a third reference plane (12); the first reference plane (10), the second reference plane (11) and the third reference plane (12) are perpendicular to each other; a through circular hole (8) is provided on the body; a plurality of calibration balls (9) are also provided on the outer side of the calibration block (5), and the plurality of calibration balls (9) are fixedly arranged relative to the body; the radii of the plurality of calibration balls (9) and the distances from the calibration balls to the first reference plane are not equal to each other.

2. The calibration device for an on-machine measurement system according to claim 1, characterized in that: There are three groups of the calibration balls (9), and the three groups of calibration balls (9) are fixedly connected to the first reference plane (11) of the main body through connecting rods; the projections of the calibration balls (9) on the first reference plane (11) and the circular holes (8) are respectively arranged close to different vertices of the main body.

3. The calibration device for an on-machine measurement system according to claim 2, characterized in that: The centers of the three groups of calibration balls (9) form a virtual triangle, and any internal angle of the virtual triangle is not less than 15 degrees.

4. The calibration device for an on-machine measurement system according to claim 1, characterized in that: A calibration base (6) and an adjustment structure (7) are provided between the calibration block and the fixing frame; the adjustment structure (7) comprises a support plate (71), the support plate (71) is located inside the fixing frame (3), a first threaded hole (72) is provided at the end of the support plate (71), an adjustment slot (73) is provided on the fixing frame (3), the support plate (71) is fixedly connected to the adjustment slot (73) by bolts, a mounting plate (74) is provided on the outer side surface of the support plate (71), the top end of the mounting plate (74) is fixedly connected to the bottom end of the calibration base (6), and the calibration base (6) is used to place the calibration block (5); the adjustment structure (7) is used to change the position of the calibration base (6) and the calibration block (5) on the fixing frame (3).

5. The calibration device for an on-machine measurement system according to claim 4, characterized in that: The mounting plate (74) is L-shaped, and a second threaded hole (13) is provided on the surface of the mounting plate (74). The second threaded hole (13) is fixedly connected to the adjustment slot (73) and the support plate (71) respectively through bolts.

6. The calibration device for an on-machine measurement system according to claim 5, characterized in that: A reinforcing block (14) is provided on the inner side wall of the mounting plate (74), both ends of the reinforcing block (14) are fixedly connected to the surface of the mounting plate (74), the reinforcing block (14) is triangular in shape, and several groups of the reinforcing blocks (14) are provided.

7. The calibration device for an on-machine measurement system according to claim 1, characterized in that: The inner cavity of the fixing frame (3) is provided with support columns (15), and the support columns (15) are provided in two groups, and the adjacent ends of the two groups of support columns (15) are arranged at an angle.

8. The calibration device for an on-machine measurement system according to claim 1, characterized in that: A reinforcing plate (16) is provided at the bottom end of the base (1), and the cross-sectional size of the reinforcing plate (16) is inversely proportional to the height from the ground.

9. The calibration device for an on-machine measurement system according to claim 1, characterized in that: A reinforcing rod (18) is provided on the base (1), and the base (1) includes a plurality of columns, which are arranged in a rectangular array and extend along the vertical direction; the two ends of the reinforcing rod (18) are respectively fixedly connected to the surfaces of two different columns, and the end of the reinforcing rod (18) is arranged at an inclined angle to the column.

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