A general-purpose center of gravity coordinate measuring device and method

Abstract

The application provides a universal center of gravity coordinate measuring device and method, a base, a support assembly, a controller, a workpiece, a computer, a scanner and a connecting line, the support assembly is fixed on the base through a screw, the workpiece is placed on a support standard ball of the support assembly, the scanner is connected with the computer through the connecting line, a three-way stress sensor is installed on the support assembly, and the three-way stress sensor is connected with the controller and the computer through the connecting line. The workpiece is placed on the support standard ball of the support assembly, and the support standard ball is in point contact with the workpiece. Point cloud data of the workpiece and the support standard ball is obtained through scanning, the support standard ball and the contact part of the workpiece are fitted through the point cloud, the center of gravity coordinate and the contact point position are obtained, the stress of each support ball is obtained in combination with the three-way stress sensor, and then the center of gravity coordinate of the workpiece is calculated. The device has the advantages of simple structure, good universality and high calculation precision.

Description

Technical Field

[0001] This invention relates to the field of center of gravity measurement technology, and in particular to a universal center of gravity coordinate measuring device and method. Background Technology

[0002] In the production of aircraft, drones, rockets, ships, automobiles, and other electronic devices, the position of the center of gravity has a significant impact on the dynamic performance of the product. Therefore, during product manufacturing and before shipment, it is often necessary to measure and adjust the center of gravity to meet performance requirements. Moreover, as these devices operate at increasingly faster speeds and require more stringent environmental adaptability, the accuracy of the measured center of gravity is constantly increasing. For example, patent CN10544855A proposes an aircraft center of gravity measurement and adjustment device. This scheme uses three points to support the aircraft, then adjusts the height of the support points, and obtains the aircraft's center of gravity based on the change in pressure on the supporting parts. This device is designed for a specific aircraft model, and the contact position is surface contact, which changes during the lifting process, resulting in large errors, a cumbersome testing process, and a risk of the aircraft tipping over. Patent CN112304408A discloses an automated aircraft weight and center of gravity measurement device. This device uses a special support device, has a complex structure, and can only be used for measuring the center of gravity of certain aircraft models. CN212409960U discloses a scanning-based center of gravity measurement device, which theoretically possesses excellent accuracy and versatility, and has a simple structure. However, it requires the product to be suspended, making it unsuitable for measuring the center of gravity of large products or products that cannot be suspended. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a universal center of gravity coordinate measuring device. By combining it with a scanning method, it can measure the center of gravity coordinates of various products such as airplanes, drones, ships, automobiles, and mannequins. It is versatile, has a simple structure, flexible support position selection, and offers advantages such as high efficiency, high precision, low cost, and universality.

[0004] The present invention provides the following technical solution:

[0005] A general-purpose center of gravity coordinate measuring device includes a base, a support assembly, a controller, a workpiece, a computer, a scanner, and connecting cables. The support assembly is fixed to the base by screws. The workpiece is placed on a support standard sphere of the support assembly, and the contact between the workpiece and the support standard sphere is point contact. The scanner is connected to the computer via connecting cables. A triaxial stress sensor is installed on the support assembly to obtain the triaxial stress when each support standard sphere supports the workpiece. The triaxial stress sensor is connected to the controller and the computer via connecting cables. The computer contains installed software.

[0006] The support assembly includes positioning pins for engaging with a set of pin holes on the base; the positioning pins are fixed to a lower fixing plate, on which a lifting mechanism is mounted; an upper fixing plate is mounted on the lifting mechanism, and a triaxial stress sensor is fixed on the upper fixing plate; a support standard ball is fixed on the triaxial stress sensor, and the height of the support standard ball can be adjusted by an upgrading mechanism so that the support standard ball supports the workpiece and bears the weight of part of the workpiece, with the support standard ball in point contact with the workpiece; the surface contour error of the support standard ball is less than 0.1mm.

[0007] The base has a set of pin holes and screw holes. Three or more support components can be distributed on the base according to the size of the workpiece being measured and the strength of the support position to ensure that the workpiece is stably supported. The pin holes are used to position the support components, and the screw holes are used to fix the support components.

[0008] The workpiece is marked with markers to stitch together data during data acquisition using a scanner, ensuring smooth scanning and obtaining point cloud data of the spatial position of the workpiece and the supporting standard sphere.

[0009] The lifting mechanism is equipped with a crank handle to adjust the height of the standard support ball, so that the standard support ball bears part of the weight of the workpiece.

[0010] A measurement method for a general-purpose centroid coordinate measuring device includes the following steps:

[0011] 1) Fix three or more support components to the base with screws, and adjust the height of the fixed support standard ball by cranking the handle so that the workpiece with the attached markings is stably supported on the support standard ball, and the support standard ball is in point contact with the workpiece.

[0012] 2) Connect the computer to the scanner and controller;

[0013] 3) Use a scanner to scan the workpiece and the supporting standard sphere to obtain point cloud data of the workpiece and the supporting standard sphere;

[0014] 4) Fit the point cloud data of each support standard sphere and the contact position of the workpiece to obtain the coordinates of the center point of each set of support standard spheres; assuming there are three support components, the three center points O A O B O c and the contact point J of the workpiece A (X) A Y A Z A J B (X) B Y B Z B J C (X)C Y C Z C ), calculate O A J A O B J B O C J C Angles α, β, and γ relative to the vertical direction;

[0015] 5) The resultant force of the workpiece exerting on the support assembly on the triaxial stress sensor is read by computer, which is F A F B F C ;

[0016] 6) Calculate F based on angles α, β, and γ. A F B F C The vertical component of gravity: G A G B G C ;

[0017] 7) Multiply the gravitational component of each supporting standard ball by the coordinates of the three corresponding contact points, sum them, and divide by the total weight of the corresponding workpiece to obtain the coordinate value of the corresponding center of gravity.

[0018] This invention discloses a universal center of gravity coordinate measuring device and method, applicable to the measurement of center of gravity coordinates of objects of various shapes and sizes, including but not limited to airplane models, drones, mannequin models, ship hulls, and model aircraft. It boasts excellent versatility and fast measurement speed, saving significant costs and time. Particularly for irregularly shaped and difficult-to-measure parts, no specialized device is required; simply adjusting the number of support components, their installation positions, and the height of the standard support ball is sufficient to measure workpieces with significant shape variations. This invention features strong applicability, simple operation, low cost, and high accuracy, meeting the requirements for measuring the center of gravity coordinates of workpieces with complex structures, materials, and diverse shapes. Attached Figure Description

[0019] Figure 1 This is an overall structural diagram of the invention;

[0020] Figure 2 This is a structural diagram of the supporting components;

[0021] Figure 3 This is a schematic diagram for calculating the center of gravity of the contact support point.

[0022] In the diagram: 1-base, 2-pin hole, 3-screw hole, 4-screw, 5-support assembly, 6-workpiece, 7-marker point, 8-scanner, 9-controller, 10-connecting cable, 11-computer, 5.1-pin, 5.2-lower fixing plate, 5.3-lifting mechanism, 5.4-upper fixing plate, 5.5-triaxial stress sensor, 5.6-support standard ball, 5.7-crank handle. Detailed Implementation

[0023] The present invention provides a scanning-based centroid coordinate measuring device and method in detail below with reference to embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0024] like Figure 1 and Figure 2 As shown, a general-purpose center of gravity coordinate measuring device includes a base 1, a support component 5, a controller 9, a workpiece 6, a computer 11, a scanner 8, and a connecting line 10. The support component 5 is fixed on the base 1 by screws 4. The workpiece 6 is placed on the support standard ball 5.6 of the support component 5. The scanner 8 is connected to the computer 11 by the connecting line (10). A triaxial stress sensor 5.6 is installed on the support component 5. The triaxial stress sensor 5.6 is connected to the controller 9 and the computer 11 by the connecting line 10.

[0025] like Figure 2 As shown, the support component 5 includes a positioning pin 5.1, which is fixed on a lower fixing plate 5.2. A lifting mechanism 5.3 is installed on the lower fixing plate 5.2, and an upper fixing plate 5.4 is installed on the lifting mechanism 5.3. A triaxial stress sensor 5.5 is fixed on the upper fixing plate 5.4, and a support standard ball 5.6 is fixed on the triaxial stress sensor 5.5. The spherical contour error of the support standard ball 5.6 is required to be less than 0.1 mm.

[0026] like Figure 1 As shown, the base 1 has a set of pin holes 2 and screw holes 3. The pin holes 2 are used to cooperate with the pins 5.1 of the support component 5 to position the support component. The screw holes 3 are used to fix the support component 5 with screws 4.

[0027] like Figure 1 and Figure 2 As shown, three or more support components 5 are fixedly distributed on the base 1.

[0028] like Figure 1 As shown, the workpiece 6 is affixed with marker points 7 so that the scanner 8 can obtain point cloud data of the workpiece 6 and the standard support ball 5.6 during scanning.

[0029] like Figure 2As shown, the lifting mechanism 5.3 is equipped with a crank handle 5.7. Cranking the crank handle 5.7 can adjust the height of the standard support ball 5.6 so that it can bear part of the weight of the workpiece 6.

[0030] The method for measuring the universal center of gravity coordinates includes the following steps:

[0031] 1) Fix three or more support components 5 to the base 1 with screws 4, and adjust the height of the fixed support standard ball 5.6 by crank handle 5.7 so that the workpiece 6 with the attached mark point 7 is stably supported on the support standard ball 5.6;

[0032] 2) Connect the computer 11 to the scanner 8 and the controller 9;

[0033] 3) Scanner 8 is used to scan workpiece 6 and supporting standard ball 5.6 to obtain point cloud data;

[0034] 4) such as Figure 3 As shown, by fitting the point cloud data of each support standard sphere 5.6 and the contact position of the workpiece 6, the coordinates O of the center point of each support standard sphere 5.6 are obtained. A O B O c and the contact point J of the workpiece 6 A (X) A， Y A， Z A J B (X) B， Y B， Z B J C (X) C， Y C， Z C ), calculate O A J A、 O B J B O C J C Angles α, β, and γ relative to the vertical direction;

[0035] 5) The resultant force of the workpiece 6 on the support component 5 on the triaxial stress sensor 5.5 is read by computer 11, which is F A F B F C ;

[0036] 6) Calculate F based on angles α, β, and γ. A F B F C The vertical component of gravity: G A G B G C ;

[0037] 7) Centroid coordinates (X) z Y z Z z The formula for calculating ) is:

[0038] .

[0039] The support component 5 is supported at different positions on the workpiece 6. Repeating steps 1)-7) and taking the average value of multiple measurements can improve the measurement accuracy.

[0040] The present invention provides a general-purpose centroid coordinate measuring device and method, which has the advantages of simple device, strong versatility, simple operation and high measurement accuracy.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Those skilled in the art can adapt and vary the invention depending on the object being measured. Any modifications, substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A measurement method for a general-purpose centroid coordinate measuring device, characterized in that... The device includes a base (1), a support assembly (5), a controller (9), a workpiece (6), a computer (11), a scanner (8), and a connecting line (10). The base (1) has a set of pin holes (2) and screw holes (3) for dispersing and fixing three or more support assemblies (5). Each support assembly (5) includes a positioning pin (5.1), a lower fixing plate (5.2), a lifting mechanism (5.3), an upper fixing plate (5.4), a triaxial stress sensor (5.5), and a support standard ball (5.6). The lifting mechanism (5.3) is equipped with a crank handle (5.7). The support standard ball (5.6) is in point contact with the workpiece (6). The scanner (8) is used to acquire point cloud data of the workpiece (6) and the support standard ball (5.6). The computer (11) is used to fit the point cloud data, calculate the contact point coordinates and force direction angle, and, combined with the force data measured by the triaxial stress sensor (5.5), calculate the workpiece's center of gravity coordinates. The measurement method of the measuring device includes the following steps: 1) Fix three or more support components (5) to the base (1) with screws (4), and adjust the height of the fixed support standard ball (5.6) by the crank (5.7) so that the workpiece (6) with the attached mark (7) is stably supported on the support standard ball (5.6); 2) Connect the computer (11) to the scanner (8) and the controller (9); 3) Use a scanner (8) to scan the workpiece (6) and the supporting standard ball (5.6) to obtain point cloud data; 4) Fit the point cloud data of the contact positions of each support standard sphere (5.6) and the workpiece (6) to obtain the coordinates O of the center point of each support standard sphere (5.6). A O B O C and the contact point J of the workpiece (6) A (X) A Y A Z A ), J B (X) B Y B Z B ), J C (X) C Y C Z C ), calculate O A J A O B J B O C J C Angles α, β, and γ relative to the vertical direction; 5) The resultant force of the workpiece (6) on the support assembly (5) on the triaxial stress sensor (5.5) is read by the computer (11), which is F A F B F C ; 6) Calculate F based on angles α, β, and γ. A F B F C The vertical component of gravity: G A G B G C ; 7) Substitute the results from steps 4 and 6 into the following formula to calculate the centroid coordinates (Xz, Yz, Zz): 。 2. The measurement method of the universal centroid coordinate measuring device according to claim 1, characterized in that, The support component (5) includes a positioning pin (5.1), which is fixed on a lower fixing plate (5.2). A lifting mechanism (5.3) is installed on the lower fixing plate (5.2), and an upper fixing plate (5.4) is installed on the lifting mechanism (5.3). A triaxial stress sensor (5.5) is fixed on the upper fixing plate (5.4), and a support standard ball (5.6) is fixed on the triaxial stress sensor (5.5).

3. The measurement method of the universal centroid coordinate measuring device according to claim 2, characterized in that, The spherical profile error of the supporting standard sphere (5.6) is less than 0.1 mm.

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