Workpiece mass center measuring device, method, computer equipment and system

Abstract

The invention discloses a workpiece mass center measuring device, method, computer equipment and system. The workpiece mass center measuring device comprises a horizontal workbench, a supporting frame set, a cross beam, a calibration sphere and a suspension assembly. The supporting frame set is arranged on the horizontal workbench and comprises two supporting frames which are oppositely arranged. The cross beam is erected on the two supporting frames; the calibration ball body is arranged on the support frame along the Z-axis direction; the suspension assembly is arranged on the cross beam, and a suspension point is arranged on the suspension assembly and used for suspending a workpiece to be detected. According to the embodiment of the invention, the to-be-measured workpiece is suspended by erecting the workpiece centroid measuring device, and the centroid coordinates of the to-be-measured workpiece are calculated in the computer equipment according to the position information measured by the measuring equipment, so that the centroid coordinates of the to-be-measured workpiece can be accurately measured; the problem that the mass center coordinates of the workpiece in three directions are difficult to accurately measure by the existing weighing measurement method is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of workpiece centroid measurement, and in particular to a workpiece centroid measurement device, method, computer equipment and system. Background Art

[0002] In the R&D and manufacturing process of complete vehicles and aircraft, the center of mass parameters are key parameters, which have a direct impact on the motion performance and safety performance. Therefore, the calibration and measurement of the center of mass parameters are crucial tasks, and are also essential key measurements in the R&D and manufacturing process.

[0003] At present, in the process of measuring the centroid of workpieces, due to the large volume and weight of some workpieces to be measured, the weighing calculation method is often used for centroid measurement. The weighing calculation method refers to using multiple scales to hold the workpiece to be measured, and using the weight indication to weight and calculate the approximate position of the centroid. This method can only roughly calculate the centroid coordinate values ​​of the workpiece to be measured in the horizontal x and y directions, and it is difficult to calculate the centroid coordinate values ​​of the workpiece to be measured in the vertical z direction. There is a problem that the centroid measurement is not accurate enough. Summary of the invention

[0004] The embodiments of the present invention provide a workpiece centroid measurement device, method, computer equipment and system to solve the problem of inaccurate centroid measurement of large workpieces.

[0005] The embodiment of the present invention provides a workpiece centroid measuring device, comprising a horizontal workbench, a support frame group, a crossbeam, a calibration sphere group and a suspension assembly;

[0006] The support frame group is arranged on the horizontal workbench, and includes two support frames arranged opposite to each other;

[0007] The crossbeam is mounted on the two support frames;

[0008] The calibration sphere group includes at least three calibration spheres, and the calibration spheres are arranged on the support frame along the Z-axis direction;

[0009] The suspension assembly is arranged on the crossbeam, and a suspension point is arranged on the suspension assembly for suspending the workpiece to be measured.

[0010] Preferably, an X-axis coordinate grating is provided on any of the support frames, and a Y-axis coordinate grating is provided on the crossbeam.

[0011] Preferably, the suspension assembly comprises a suspension ring and a workpiece suspension rope;

[0012] The lifting ring is sleeved on the crossbeam, and the hanging point is arranged on the lifting ring;

[0013] One end of the workpiece hanging rope is assembled on the hanging point, and the other end is used to fix the workpiece to be measured.

[0014] The embodiment of the present invention also provides a method for measuring the centroid of a workpiece, comprising:

[0015] Based on the workpiece centroid measuring device, a platform coordinate system is constructed to obtain the plane normal vector and the suspension point coordinates of the horizontal workbench in the platform coordinate system;

[0016] Assembling the workpiece to be measured on a suspension assembly, and obtaining a vertical line corresponding to the workpiece to be measured;

[0017] When the workpiece to be measured is in a first suspension posture and a second suspension posture, coordinate transformation is performed on the vertical line to obtain a first space straight line corresponding to the first suspension posture and a second space straight line corresponding to the second suspension posture;

[0018] The coordinates of the intersection of the first spatial straight line and the second spatial straight line are determined as the coordinates of the center of mass of the workpiece to be measured.

[0019] Preferably, the platform coordinate system is constructed based on the workpiece centroid measuring device, and the plane normal vector and the suspension point coordinates of the horizontal workbench in the platform coordinate system are obtained, including:

[0020] Based on the horizontal workbench and calibration sphere group in the workpiece centroid measuring device, a platform coordinate system is constructed;

[0021] Based on the platform coordinate system, the plane normal vector of the horizontal workbench and the suspension point coordinates corresponding to the suspension point are obtained.

[0022] Preferably, when the workpiece to be measured is in the first suspension posture and the second suspension posture, coordinate transformation is performed on the vertical line to obtain a first space straight line corresponding to the first suspension posture and a second space straight line corresponding to the second suspension posture, respectively, including:

[0023] Select three fixed points that are not on the same straight line from the workpiece to be measured as target measurement points;

[0024] When the workpiece to be measured is in a first suspension posture, a first workpiece coordinate system corresponding to the first suspension posture is constructed based on the target measurement point, a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system is obtained, and a coordinate transformation is performed on the perpendicular line vector based on the first coordinate transformation matrix to obtain a first space straight line in the first workpiece coordinate system;

[0025] When the workpiece to be measured is in the second suspension posture, a second workpiece coordinate system corresponding to the second suspension posture is constructed based on the target measurement point, and a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system is obtained. The coordinate transformation of the perpendicular line vector is performed based on the second coordinate transformation matrix to obtain a second spatial straight line in the second workpiece coordinate system.

[0026] Preferably, constructing a first workpiece coordinate system corresponding to the first suspension posture based on the target measurement point, acquiring a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system, performing coordinate transformation on the perpendicular line vector based on the first coordinate transformation matrix, and acquiring a first space straight line in the first workpiece coordinate system, includes:

[0027] Based on the target measurement point, a first workpiece coordinate system is acquired by fitting using a best fitting method;

[0028] Acquire a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system according to the coordinates of the target measurement point in the first workpiece coordinate system and the coordinates of the platform coordinate system;

[0029] Select any two points on the vertical line in the platform coordinate system as first coordinate transformation points, input the two first coordinate transformation points into the first coordinate transformation matrix, obtain two first space straight line coordinates in the first workpiece coordinate system, and obtain the first space straight line equation according to the first space straight line coordinates;

[0030] The method of constructing a second workpiece coordinate system corresponding to the second suspension posture based on the target measurement point, acquiring a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system, and performing coordinate transformation on the perpendicular line vector based on the second coordinate transformation matrix to acquire a second space straight line in the second workpiece coordinate system includes:

[0031] Based on the target measurement point, a second workpiece coordinate system is acquired by fitting using a best fitting method;

[0032] Acquire a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system according to the coordinates of the target measurement point in the second workpiece coordinate system and the coordinates of the platform coordinate system;

[0033] Select any two points on the vertical line in the platform coordinate system as second coordinate transformation points, input the two second coordinate transformation points into the second coordinate transformation matrix, obtain two second space straight line coordinates in the second workpiece coordinate system, and obtain the second space straight line equation according to the second space straight line coordinates.

[0034] Preferably, determining the coordinates of the intersection of the first space straight line and the second space straight line as the coordinates of the centroid of the workpiece to be measured comprises:

[0035] The first spatial straight line equation and the second spatial straight line equation are solved together to obtain the coordinates of the intersection of the first spatial straight line and the second spatial straight line, and the coordinates of the intersection are determined as the coordinates of the center of mass of the workpiece to be measured.

[0036] An embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer device implements the above-mentioned workpiece centroid measurement method when executing the computer program.

[0037] The embodiment of the present invention further provides a workpiece centroid measurement system, comprising the workpiece centroid measurement device, the computer device, the measuring instrument and the coordinate digital display;

[0038] The measuring instrument is used to measure the position information of the horizontal workbench, the calibration sphere group, the suspension assembly and the workpiece to be measured, and transmit the position information to the computer device, so that the computer device calculates the centroid coordinates of the workpiece to be measured according to the position information;

[0039] The coordinate digital display is used to measure the plane coordinates of the suspension component and transmit the plane coordinates to the computer device so that the computer device determines the coordinates of the suspension point according to the plane coordinates;

[0040] The computer device is used to calculate the centroid coordinates of the workpiece to be measured according to the position information.

[0041] Preferably, the measuring instrument is arranged on one side of the workpiece centroid measuring device to perform non-contact measurement of the position information of the horizontal workbench, the calibration sphere group, the suspension assembly and the workpiece to be measured;

[0042] The coordinate digital display is electrically connected to the X-axis coordinate grating and the Y-axis coordinate grating on the support frame;

[0043] The computer device is electrically connected to the measuring instrument.

[0044] The workpiece center of mass measuring device, method, computer equipment and system provided in the embodiments of the present invention, by setting up a workpiece center of mass measuring device to suspend the workpiece to be measured, using a measuring instrument to measure and transmit position information, establishing a platform coordinate system in the computer equipment, and calculating the coordinates of the intersection of the first spatial straight line and the second spatial straight line in the workpiece coordinate system when the workpiece to be measured is in a first suspension posture and a second suspension posture, to obtain the center of mass coordinates of the workpiece to be measured. The center of mass coordinate parameters of the workpiece to be measured in the x, y, and z directions can be accurately measured, solving the problem that the existing weighing measurement method is difficult to accurately measure the center of mass coordinates of the workpiece in three directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0046] Figure 1 is a schematic diagram of the overall structure of a workpiece centroid measuring device in one embodiment of the present invention;

[0047] Figure 2 is a flow chart of a method for measuring the centroid of a workpiece in one embodiment of the present invention;

[0048] Figure 3 is another flow chart of a method for measuring the centroid of a workpiece in one embodiment of the present invention;

[0049] Figure 4 is another flow chart of a method for measuring the centroid of a workpiece in one embodiment of the present invention;

[0050] Figure 5 is another flow chart of a method for measuring the centroid of a workpiece in one embodiment of the present invention;

[0051] Figure 6 is another flow chart of a method for measuring the centroid of a workpiece in one embodiment of the present invention.

[0052] In the figure: 1. horizontal workbench; 2. support frame assembly; 21. support frame; 22. column; 3. crossbeam; 4. calibration sphere; 5. suspension assembly; 51. lifting ring; 52. workpiece lifting rope. DETAILED DESCRIPTION

[0053] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0055] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] The embodiment of the present invention provides a workpiece centroid measuring device, such as Figure 1 As shown, the workpiece centroid measuring device includes a horizontal workbench 1, a support frame group 2, a crossbeam 3, a calibration sphere group 4 and a suspension assembly 5; the support frame group 2 is arranged on the horizontal workbench 1, and includes two support frames 21 arranged opposite to each other, and an X-axis coordinate grating is provided on any support frame 21; the crossbeam 3 is mounted on the two support frames 21, and a Y-axis coordinate grating is provided on the crossbeam 3; the calibration sphere group includes at least three calibration spheres 4, and the calibration spheres 4 are arranged on the support frame 21 along the Z-axis direction; the suspension assembly 5 is arranged on the crossbeam 3, and a suspension point is provided on the suspension assembly for suspending the workpiece to be measured.

[0057] The horizontal workbench 1 is a cast iron platform with precise flatness and levelness.

[0058] The support frame group 2 includes two U-shaped metal frames mounted on the horizontal workbench 1, each square metal frame includes two columns 22 perpendicular to the horizontal workbench 1 and a support frame 21 mounted between the two columns 22, the support frame 21 is parallel to the horizontal workbench 1, the columns 22 of the two U-shaped metal frames are parallel to each other, and the support frames 21 of the two U-shaped metal frames are parallel to each other. In this example, an X-axis coordinate grating is inlaid on any one of the support frames 21 to accurately position the workpiece to be measured in the X-axis direction.

[0059] The crossbeam 3 is a metal square rod, which is mounted on two support frames 21 and is perpendicular to the two support frames 21. The crossbeam 3 can be translated on the support frames 21 to facilitate adjustment of the X-axis coordinate value of the workpiece to be measured suspended by the suspension assembly 5. The crossbeam 3 is inlaid with a Y-axis coordinate grating to accurately position the workpiece to be measured in the Y-axis direction.

[0060] The calibration sphere 4 is a metal sphere or hemisphere. As an example, the calibration sphere 4 is embedded in the column of the support frame group 2, and the Z-axis coordinate can be determined according to its position on the column. In this example, the number of calibration spheres 4 can be 16, and each column of the support frame group 2 is provided with 4 calibration spheres 4, so that the platform coordinate system can be constructed in the computer device based on the calibration sphere group.

[0061] As an example, the workpiece centroid measuring device includes a horizontal workbench 1, a support frame group 2, a calibration sphere group and a suspension assembly 5. As a cast iron platform with precise flatness and horizontality, the horizontal workbench 1 can provide a horizontal reference for establishing a platform coordinate system, and can also provide a stable support for the hoisting of the workpiece to be measured, ensuring that the vertical line of the workpiece to be measured is strictly perpendicular to the horizontal workbench 1 when suspended, thereby ensuring the accuracy of subsequent measurements. The support frame group 2 mounted on the horizontal workbench 1 is used as a hoisting support structure for the workpiece to be measured, so that the workpiece to be measured can be hoisted in the workpiece centroid measuring device, and the hoisting position can be flexibly moved in the workpiece centroid measuring device. The support frame group 2 can include two square metal frames mounted on the horizontal workbench 1, each square metal frame includes two columns perpendicular to the horizontal workbench 1 and a support frame 21 mounted between the two columns and parallel to the plane of the horizontal workbench 1, the columns of the two square metal frames are parallel to each other, and the support frames 21 of the two square metal frames are parallel to each other. The crossbeam 3 is a metal square bar, which is mounted on two support frames 21 and is perpendicular to the two support frames 21. The crossbeam 3 can translate on the support frames 21. The suspension assembly 5 is mounted on the crossbeam 3 and is used to suspend the workpiece to be measured. The suspension assembly 5 can translate on the crossbeam 3. An X-axis coordinate grating is inlaid on any one of the support frames 21, and a Y-axis coordinate grating is inlaid on the crossbeam 3. By making the suspension assembly 5 suspend the workpiece to be measured and translate on the crossbeam 3, and the crossbeam 3 translates on the two support frames 21, the suspension position of the workpiece to be measured in the workpiece centroid measuring device can be changed, and at the same time, the X-axis coordinate grating can detect the X-axis coordinate value of the workpiece to be measured in the workpiece centroid measuring device, and the Y-axis coordinate grating can detect the Y-axis coordinate value of the workpiece to be measured in the workpiece centroid measuring device. The calibration sphere 4 is a metal sphere or hemisphere, which is inlaid on the column of the support frame group 2 and is used as a measurement reference to determine the direction of the Z axis in the workpiece centroid measuring device.

[0062] In one embodiment, the suspension assembly 5 includes a lifting ring 51 and a workpiece lifting rope 52; the lifting ring 51 is mounted on the beam 3, and a hanging point is provided on the lifting ring 51; one end of the workpiece lifting rope 52 is assembled on the hanging point, and the other end is used to fix the workpiece to be measured.

[0063] As an example, the suspension assembly 5 includes a lifting ring 51 and at least two workpiece lifting ropes 52. The lifting ring 51 is mounted on the crossbeam 3 and can be translated on the crossbeam 3. A hanging point is provided below the lifting ring 51, and the height of the hanging point in the workpiece centroid measuring device is always constant. The workpiece hanging rope 52 can be used to hang the workpiece to be measured due to the different shapes and sizes of the workpiece to be measured. The upper ends of the multiple workpiece hanging ropes 52 are combined into a single point and fixed at the hanging point, and the lower ends are respectively fixed on the workpiece to be measured, so that the hanging point can be always fixed, and the position of the hanging point will not be changed due to the change of the hanging posture of the workpiece to be measured, thereby reducing the measurement error.

[0064] In one embodiment, a method for measuring the centroid of a workpiece is provided, and the method is described by taking the application of the method in a computer device as an example. Figure 2 As shown, the workpiece centroid measurement method includes:

[0065] S201: constructing a platform coordinate system based on the workpiece centroid measuring device, and obtaining the plane normal vector and the suspension point coordinates of the horizontal workbench in the platform coordinate system;

[0066] S202: Assembling the workpiece to be measured on the suspension assembly, and obtaining a vertical line corresponding to the workpiece to be measured;

[0067] S203: When the workpiece to be measured is in a first suspension posture and a second suspension posture, coordinate transformation is performed on the vertical line to obtain a first space straight line corresponding to the first suspension posture and a second space straight line corresponding to the second suspension posture;

[0068] S204: Determine the coordinates of the intersection of the first spatial straight line and the second spatial straight line as the coordinates of the centroid of the workpiece to be measured.

[0069] Among them, the platform coordinate system is a coordinate system established with the horizontal workbench 1 as the vector reference in the x-axis direction and the y-axis direction, and the calibration sphere group as the vector reference in the z-axis direction. During the coordinate system establishment process, the computer device receives the position information of the calibration sphere group and the horizontal workbench 1 sent by the measuring instrument, and the computer device calculates the platform coordinate system by establishing a conversion matrix between the digital-analog coordinate system and the horizontal workbench 1. The plane normal vector includes the plane normal vector i corresponding to the x-axis direction, the plane normal vector j corresponding to the y-axis direction, and the plane normal vector k corresponding to the z-axis direction. The coordinates of the suspension point are (x0, y0, z0), and the computer device can obtain the coordinates of the suspension point by receiving the coordinate data sent by the coordinate digital display.

[0070] As an example, in step S201, the measuring instrument performs non-contact measurement on the calibration sphere group and the horizontal workbench 1, and transmits the position information to the computer device for calculation to obtain a platform coordinate system based on the horizontal workbench 1 and the calibration sphere group. In the platform coordinate system, the plane normal vector includes the plane normal vector i corresponding to the x-axis direction, the plane normal vector j corresponding to the y-axis direction, and the plane normal vector k corresponding to the z-axis direction. The suspension point coordinates (x0, y0, z0) of the workpiece to be measured are detected by the coordinate digital display and the coordinate data is transmitted to the computer device.

[0071] As an example, in step S202, in the platform coordinate system, the vertical line can be expressed by the vertical line equation as follows: Wherein i, j and k are the plane normal vectors of the platform coordinate system, x0 is the x-axis coordinate of the suspension point of the workpiece to be measured in the platform coordinate system, y0 is the y-axis coordinate of the suspension point of the workpiece to be measured, and z0 is the z-axis coordinate of the suspension point of the workpiece to be measured.

[0072] Among them, the first suspension posture is the suspension posture of the workpiece to be measured at any time of suspension, and the second suspension posture is the suspension posture of the workpiece to be measured after obtaining the first spatial straight line by adjusting the length of the workpiece suspension rope 52 or fixing the position of the workpiece to be measured.

[0073] The first spatial straight line is the representation of the vertical line in the workpiece coordinate system when the workpiece is in the first suspension posture; the second spatial straight line is the representation of the vertical line in the workpiece coordinate system when the workpiece is in the second suspension posture. The workpiece coordinate system is associated with the workpiece to be measured. When the suspension posture changes, the relative position of the workpiece to be measured in the platform coordinate system moves, and the relative position of the workpiece coordinate system in the platform coordinate system also moves with the workpiece to be measured.

[0074] As an example, in step S203, when the workpiece to be measured is in the first suspension posture, the computer device performs coordinate transformation on the vertical line, and converts the linear equation of the vertical line in the platform coordinate system into Transformed into the first space straight line equation in the workpiece coordinate system Among them, i1, j1 and k1 are the plane normal vectors of the workpiece coordinate system in the first suspension posture, x1 is the x-axis coordinate of the suspension point of the workpiece to be measured in the workpiece coordinate system, y1 is the y-axis coordinate of the suspension point of the workpiece to be measured in the workpiece coordinate system, and z1 is the z-axis coordinate of the suspension point of the workpiece to be measured in the workpiece coordinate system.

[0075] Accordingly, when the workpiece to be measured is in the second suspension posture, the computer device performs coordinate transformation on the vertical line, and converts the linear equation of the vertical line in the platform coordinate system into Transformed into the second space straight line equation in the workpiece coordinate system Among them, i2, j2 and k2 are the plane normal vectors of the workpiece coordinate system in the second suspension posture, x2 is the x-axis coordinate of the suspension point of the workpiece to be measured in the workpiece coordinate system, y2 is the y-axis coordinate of the suspension point of the workpiece to be measured in the workpiece coordinate system, and z2 is the z-axis coordinate of the suspension point of the workpiece to be measured in the workpiece coordinate system.

[0076] As an example, since the vertical line of gravity of an object always passes through the center of gravity, the coordinates of the intersection of the first spatial straight line and the second spatial straight line in the workpiece coordinate system are obtained before and after the suspension posture of the workpiece to be measured is changed, and determined as the center of gravity coordinates of the workpiece to be measured. In a uniform gravitational field, the center of gravity and the center of mass of an object are usually at the same imaginary point, so the center of gravity coordinates of the workpiece to be measured can be approximately determined as the center of mass coordinates.

[0077] In this example, by establishing a platform coordinate system, obtaining the vertical line of gravity corresponding to the workpiece to be measured in the platform coordinate system, and performing coordinate transformation on the vertical line of gravity when the workpiece to be measured is in the first suspension posture and the second suspension posture, respectively, calculating and obtaining the first spatial straight line and the second spatial straight line, and using the coordinates of the intersection of the first spatial straight line and the second spatial straight line as the center of mass coordinates, the coordinate parameters of the center of mass of the workpiece to be measured in the x, y, and z directions can be accurately measured, which solves the problem that the existing weighing measurement method is difficult to accurately measure the center of mass coordinate parameters of the workpiece in three directions.

[0078] In one embodiment, if Figure 3 As shown, step S201, i.e. building a platform coordinate system based on the workpiece centroid measuring device, obtaining the plane normal vector and suspension point coordinates of the horizontal workbench 1 in the platform coordinate system includes:

[0079] S301: constructing a platform coordinate system based on the horizontal worktable 1 and the calibration sphere group in the workpiece centroid measurement device;

[0080] S302: Based on the platform coordinate system, obtain the plane normal vector of the horizontal workbench and the suspension point coordinates corresponding to the suspension point.

[0081] As an example, in step S301, the measuring instrument simultaneously performs non-contact measurement on the calibration sphere group and the horizontal worktable 1, and transmits the relative position information of the calibration sphere group and the horizontal worktable 1 to the computer device for calculation. Specifically, the point information of the calibration sphere group and the point information of several fixed points on the horizontal worktable 1 can be transmitted to the computer device, and the computer device performs coordinate conversion according to the acquired point information to establish a platform coordinate system.

[0082] As an example, in step S302, the computer device obtains the plane normal vectors i, j, k of the horizontal workbench 1 according to the relative position information of the horizontal workbench 1 and the calibration sphere group sent by the measuring instrument. The coordinate digital display can be used to obtain the coordinate values ​​of the suspension component 5 detected at the X-axis coordinate grating and the Y-axis coordinate grating, and because the height of the suspension point of the suspension component 5 in the workpiece centroid measuring device is always constant and the actual height data is easy to measure, the coordinate digital display can obtain the coordinate position of the suspension point of the suspension component 5 in the platform coordinate system as (x0, y0, z0). The coordinate digital display transmits the obtained coordinate position to the computer device.

[0083] In one embodiment, if Figure 4 As shown, step S203, i.e., when the workpiece to be measured is in the first suspension posture and the second suspension posture, coordinate transformation is performed on the vertical line respectively to obtain a first space straight line corresponding to the first suspension posture and a second space straight line corresponding to the second suspension posture, including:

[0084] S401: selecting three fixed points that are not on the same straight line from the workpiece to be measured as target measurement points;

[0085] S402: When the workpiece to be measured is in a first suspension posture, a first workpiece coordinate system corresponding to the first suspension posture is constructed based on the target measurement point, a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system is obtained, and a coordinate transformation is performed on the vertical line based on the first coordinate transformation matrix to obtain a first space straight line in the first workpiece coordinate system;

[0086] S403: When the workpiece to be measured is in the second suspension posture, a second workpiece coordinate system corresponding to the second suspension posture is constructed based on the target measurement point, a second coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system is obtained, and the coordinate transformation of the vertical line is performed based on the second coordinate transformation matrix to obtain a second spatial straight line in the second workpiece coordinate system.

[0087] Among them, the target measurement points are points related to the workpiece to be measured in six directions. These points can be: the center point of the circle measured by the sample point, the piercing point of the cylinder and the plane, the corner point of the intersection of three planes, the intersection point of two spatial cylinder axes, the center point of the sphere, the vertex of the cone, etc.

[0088] As an example, in S401, three fixed points related to the workpiece to be measured in six directions are selected as target measurement points, and the position information of the target measurement points is measured by a measuring instrument and transmitted to a computer device.

[0089] The first workpiece coordinate system is a workpiece coordinate system established when the workpiece to be measured is in the first suspension posture according to the position information of the three target measurement points measured by the current measuring instrument. The first coordinate conversion matrix is ​​a conversion matrix that can convert the coordinate value of a certain point in the platform coordinate system into the coordinate value in the first workpiece coordinate system.

[0090] As an example, in step S402, when the workpiece to be measured is in the first suspension posture, firstly, the first workpiece coordinate system corresponding to the first suspension posture is constructed according to the position information of the three target measurement points measured by the measuring instrument. Then, according to the coordinates of the target measurement points in the platform coordinate system and the first workpiece coordinate system, the first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system is obtained. Then, based on the first coordinate transformation matrix, the coordinate transformation of the vertical line is performed, and the straight line equation of the vertical line in the platform coordinate system is converted to Transformed into the first space straight line equation in the first workpiece coordinate system Among them, i1, j1 and k1 are the plane normal vectors of the first workpiece coordinate system, x1 is the x-axis coordinate of the suspension point of the workpiece to be measured in the first workpiece coordinate system, y1 is the y-axis coordinate of the suspension point of the workpiece to be measured in the first workpiece coordinate system, and z1 is the z-axis coordinate of the suspension point of the workpiece to be measured in the first workpiece coordinate system.

[0091] Among them, similar to the first workpiece coordinate system, the second workpiece coordinate system is a workpiece coordinate system established according to the position information of the three target measurement points measured by the current measuring instrument when the workpiece to be measured is in the second suspension posture. The second coordinate transformation matrix is ​​a transformation matrix that can transform the coordinate value of a certain point in the platform coordinate system into the coordinate value in the second workpiece coordinate system.

[0092] As an example, in step S403, when the workpiece to be measured is in the second suspension posture, firstly, the second workpiece coordinate system corresponding to the second suspension posture is constructed according to the position information of the three target measurement points measured by the measuring instrument. Then, according to the coordinates of the target measurement points in the platform coordinate system and the second workpiece coordinate system, the second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system is obtained. Then, based on the second coordinate transformation matrix, the coordinate transformation of the vertical line is performed, and the straight line equation of the vertical line in the platform coordinate system is converted to Transformed into the second space straight line equation in the second workpiece coordinate system Among them, i2, j2 and k2 are the plane normal vectors of the second workpiece coordinate system under the second suspension posture, x2 is the x-axis coordinate of the suspension point of the workpiece to be measured in the second workpiece coordinate system, y2 is the y-axis coordinate of the suspension point of the workpiece to be measured in the second workpiece coordinate system, and z2 is the z-axis coordinate of the suspension point of the workpiece to be measured in the second workpiece coordinate system.

[0093] In one embodiment, if Figure 5As shown, step S402, i.e., constructing a first workpiece coordinate system corresponding to the first suspension posture based on the target measurement point, obtaining a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system, performing coordinate transformation on the vertical line vector based on the first coordinate transformation matrix, and obtaining a first space straight line in the first workpiece coordinate system includes:

[0094] S501: Based on the target measurement point, a first workpiece coordinate system is obtained by fitting using a best fitting method;

[0095] S502: acquiring a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system according to the coordinates of the target measurement point in the first workpiece coordinate system and the coordinates of the platform coordinate system;

[0096] S503: Select any two points on the vertical line in the platform coordinate system as the first coordinate transformation points, input the two first coordinate transformation points into the first coordinate transformation matrix, obtain two first space straight line coordinates in the first workpiece coordinate system, and obtain the first space straight line equation according to the first space straight line coordinates.

[0097] Among them, the best fit method is one of the commonly used methods to establish a spatial coordinate system. Specifically, the workpiece coordinate system is calculated by establishing a transformation matrix between the digital-analog coordinate system and the workpiece to be measured. It is suitable for parts with features that can be measured or constructed, and the evaluation method of the parts must be in the original digital-analog coordinate system, or the digital-analog coordinate system is relatively complex and it is difficult to fit directly using the 3-2-1 method.

[0098] As an example, in step S501, when the workpiece to be measured is in a first suspension posture, firstly, a first workpiece coordinate system corresponding to the first suspension posture is constructed using a best fitting method according to position information of three target measurement points measured by a measuring instrument.

[0099] As an example, in step S502, when the workpiece to be measured is in the first suspension posture, according to the position information of the three target measurement points measured by the measuring instrument, the coordinates of the three target measurement points in the platform working system (marked as A) are obtained and set as the set P A , and the coordinates of the three target measurement points in the first workpiece coordinate system (marked as B) are set as set P B , then the coordinate transformation process of the target measurement point coordinates in the platform coordinate system and the first workpiece coordinate system using the first workpiece coordinate system can be expressed by the formula P B =R1*P A +T1 represents, where R1 is the first coordinate transformation matrix and T1 is the first displacement transformation vector. The first coordinate transformation matrix and the first displacement transformation vector can be obtained by solving the formula using Singular Value Decomposition (SVD).

[0100] As an example, in step S503, the coordinates (x0, y0, z0) of the suspension point in the platform coordinate system and the coordinates of any point on the vertical line are selected as the coordinates of the first coordinate conversion point in the platform coordinate system, and the coordinates of the first coordinate conversion point are taken as P A Substitute into the formula P B =R1*P A +T1, obtain the coordinates of the two first coordinate transformation points in the first workpiece coordinate system when the first suspension posture is obtained. A straight line can be determined based on the two points, and the first space straight line equation can be obtained based on the coordinates of the two first coordinate transformation points in the first workpiece coordinate system.

[0101] In one embodiment, if Figure 6 As shown, step S403, i.e., based on the target measurement point, constructing a second workpiece coordinate system corresponding to the second suspension posture, obtaining a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system, performing coordinate transformation on the vertical line vector based on the second coordinate transformation matrix, and obtaining a second space straight line in the second workpiece coordinate system includes:

[0102] S601: Based on the target measurement point, a second workpiece coordinate system is obtained by fitting using the best fitting method;

[0103] S602: Acquire a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system according to the coordinates of the target measurement point in the second workpiece coordinate system and the coordinates of the platform coordinate system;

[0104] S603: Select any two points on the vertical line in the platform coordinate system as second coordinate transformation points, input the two second coordinate transformation points into the second coordinate transformation matrix, obtain two second space straight line coordinates in the second workpiece coordinate system, and obtain the second space straight line equation according to the second space straight line coordinates.

[0105] The second workpiece coordinate system and the first workpiece coordinate system are established based on the same three target measurement points. The first workpiece coordinate system and the second workpiece coordinate system are only related to the workpiece to be measured, and are distinguished into the first workpiece coordinate system and the second workpiece coordinate system only because of their different positions in the platform coordinate system.

[0106] As an example, in step S601, when the workpiece to be measured is in the second suspension posture, firstly, the first workpiece coordinate system corresponding to the first suspension posture is constructed by using the best fitting method according to the position information of the three target measurement points measured by the measuring instrument.

[0107] As an example, in step S602, when the workpiece to be measured is in the second suspension posture, according to the current position information of the three target measurement points measured by the measuring instrument, the coordinates of the three target measurement points in the platform working system (marked as A) are obtained and set as set P′ A, and the coordinates of the three target measurement points in the second workpiece coordinate system (marked as B) are set to set P′ B , then the coordinate transformation process of the target measurement point coordinates in the platform coordinate system and the second workpiece coordinate system using the second workpiece coordinate system can be expressed by the formula P′ B =R2*P′ A +T2 represents, where R2 is the second coordinate transformation matrix, and T2 is the second displacement transformation vector. The second coordinate transformation matrix and the second displacement transformation vector can be obtained by solving the formula using Singular Value Decomposition (SVD).

[0108] As an example, in step S603, the coordinates of the suspension point in the platform coordinate system (x0, y0, z0) and the coordinates of any point on the vertical line are selected as the coordinates of the second coordinate conversion point in the platform coordinate system, and the coordinates of the second coordinate conversion point are taken as P′ A Substitute into the formula P′ B =R2*P′ A +T2, obtain the coordinates of the two second coordinate transformation points in the second workpiece coordinate system when the second suspension posture is obtained. A straight line can be determined based on the two points, and the second space straight line equation can be obtained based on the coordinates of the two second coordinate transformation points in the second workpiece coordinate system.

[0109] In one embodiment, step S204, i.e. determining the coordinates of the intersection of the first spatial straight line and the second spatial straight line as the coordinates of the centroid of the workpiece to be measured, comprises:

[0110] The first spatial straight line equation and the second spatial straight line equation are solved together to obtain the coordinates of the intersection of the first spatial straight line and the second spatial straight line, and the coordinates of the intersection are determined as the coordinates of the center of mass of the workpiece to be measured.

[0111] As an example, the first space straight line equation is and the second space line equation Get the system of equations Solving the equations, we can get the coordinates of the intersection of the first space line and the second space line. Since the vertical line of the object always passes through the center of gravity, after changing the suspension posture of the workpiece to be measured, we can calculate the coordinates of the intersection of the first space line in the first workpiece coordinate system at the first suspension posture and the second space line in the second workpiece coordinate system at the second suspension posture, and get the coordinates of the center of gravity of the workpiece to be measured. In a uniform gravitational field, the center of gravity and center of mass of an object are usually at the same imaginary point, so the coordinates of the center of gravity of the workpiece to be measured can be approximated as its center of mass coordinates.

[0112] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0113] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the computer device executes the computer program, the workpiece centroid measurement method in any of the above embodiments is implemented. Figure 2 S201-S204 as shown, or Figures 3 to 6 To avoid repetition, it will not be described here.

[0114] In one embodiment, a workpiece centroid measurement system is provided, including the workpiece centroid measurement device in the above embodiment, the computer equipment in the above embodiment, a measuring instrument and a coordinate digital display; the measuring instrument is used to measure the position information of the horizontal workbench 1, the calibration sphere group, the suspension component 5 and the workpiece to be measured, and transmit the position information to the computer equipment; the coordinate digital display is used to display the plane coordinates of the suspension component 5; the computer equipment is used to calculate the centroid coordinates of the workpiece to be measured based on the position information.

[0115] The measuring instrument can be a laser measuring instrument or a depth camera, which can perform non-contact measurement on the coordinate sphere, the horizontal workbench 1 and the workpiece to be measured, collect the position information of the horizontal workbench 1, the calibration sphere group and the suspension component 5 and transmit it to the computer device, collect the position information of the workpiece to be measured in the first suspension posture and the second suspension posture and transmit it to the computer device. The coordinate digital display is used to collect the coordinates of the suspension point in real time, display the coordinates of the suspension point, and transmit the coordinates of the suspension point to the computer device.

[0116] As an example, the computer device receives the position information of the horizontal worktable 1, the calibration sphere group and the suspension component 5 sent by the measuring instrument, and performs coordinate conversion according to the acquired position information, establishes the platform coordinate system, and obtains the plane normal vectors i, j, k of the horizontal worktable 1. When the workpiece to be measured is in the first suspension posture, the computer device receives the position information of the workpiece to be measured sent by the measuring instrument, and establishes the first workpiece coordinate system according to the acquired position information, and then converts the vertical line of the workpiece to be measured in the platform coordinate system into the first space line in the first workpiece coordinate system; when the workpiece to be measured is in the second suspension posture, the computer device receives the position information of the workpiece to be measured sent by the measuring instrument, and establishes the second workpiece coordinate system according to the acquired position information, and then converts the vertical line of the workpiece to be measured in the platform coordinate system into the second space line in the second workpiece coordinate system. The computer device calculates the intersection of the first space line and the second space line, and uses the intersection as the center of mass of the workpiece to be measured.

[0117] In this example, a workpiece centroid measuring device is set up to suspend the workpiece to be measured, and the position information is measured and transmitted using a measuring instrument. A platform coordinate system is established in a computer device, and the coordinates of the intersection of the first spatial straight line and the second spatial straight line in the workpiece coordinate system are calculated when the workpiece to be measured is in a first suspension posture and a second suspension posture to obtain the centroid coordinates of the workpiece to be measured. The coordinate parameters of the workpiece to be measured in the x, y, and z directions can be accurately measured, which solves the problem that the existing weighing measurement method is difficult to accurately measure the centroid coordinate parameters of the workpiece in three directions.

[0118] In one embodiment, the measuring instrument is arranged on one side of the workpiece centroid measuring device to perform non-contact measurement on the horizontal workbench 1, the calibration sphere group, the suspension assembly 5 and the workpiece to be measured; the coordinate digital display is electrically connected to the X-axis coordinate grating and the Y-axis coordinate grating.

[0119] As an example, the measuring instrument and the workpiece centroid measuring device are placed in the same space, and the measuring instrument is placed on one side of the workpiece centroid measuring device, without direct contact with the workpiece centroid measuring device, and non-contact measurement is performed on the horizontal workbench 1, the calibration sphere group, the suspension assembly 5 and the workpiece to be measured, and the measured position information is sent to the computer device. During the measurement process, the relative position of the measuring instrument and the workpiece centroid measuring device does not change. The coordinate digital display is electrically connected to the X-axis coordinate grating and the Y-axis coordinate grating, receives the coordinate data returned by the X-axis coordinate grating and the Y-axis coordinate grating, and displays the coordinate data in real time, and sends the coordinate data to the computer device.

[0120] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0121] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0122] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A workpiece centroid measuring device, characterized in that: It includes a horizontal workbench, a support frame group, a crossbeam, a calibration sphere group and a suspension assembly; The support frame group is arranged on the horizontal workbench, and includes two support frames arranged opposite to each other; The crossbeam is mounted on the two support frames; The calibration sphere group includes at least three calibration spheres, and the calibration spheres are arranged on the support frame along the Z-axis direction; The suspension assembly is arranged on the crossbeam, and a suspension point is arranged on the suspension assembly for suspending the workpiece to be measured.

2. The workpiece centroid measuring device according to claim 1, characterized in that: Any of the support frames is provided with an X-axis coordinate grating, and the crossbeam is provided with a Y-axis coordinate grating.

3. The workpiece centroid measuring device according to claim 1, characterized in that: The suspension assembly includes a lifting ring and a workpiece lifting rope; The lifting ring is sleeved on the crossbeam, and the hanging point is arranged on the lifting ring; One end of the workpiece hanging rope is assembled on the hanging point, and the other end is used to fix the workpiece to be measured.

4. A method for measuring the centroid of a workpiece, characterized in that: include: Construct a platform coordinate system based on the workpiece centroid measuring device according to any one of claims 1 to 3, and obtain the plane normal vector and suspension point coordinates of the horizontal workbench in the platform coordinate system; Assembling the workpiece to be measured on a suspension assembly, and obtaining a vertical line corresponding to the workpiece to be measured; When the workpiece to be measured is in a first suspension posture and a second suspension posture, coordinate transformation is performed on the vertical line to obtain a first space straight line corresponding to the first suspension posture and a second space straight line corresponding to the second suspension posture; The coordinates of the intersection of the first spatial straight line and the second spatial straight line are determined as the coordinates of the center of mass of the workpiece to be measured.

5. The method for measuring the centroid of a workpiece according to claim 4, characterized in that: The device for measuring the centroid of a workpiece according to any one of claims 1 to 3 is used to construct a platform coordinate system, and obtain the plane normal vector and the suspension point coordinates of the horizontal workbench in the platform coordinate system, including: Based on the horizontal workbench and the calibration sphere group in the workpiece centroid measuring device according to any one of claims 1 to 3, construct a platform coordinate system; Based on the platform coordinate system, the plane normal vector of the horizontal workbench and the suspension point coordinates corresponding to the suspension point are obtained.

6. The method for measuring the centroid of a workpiece according to claim 4, characterized in that: When the workpiece to be measured is in the first suspension posture and the second suspension posture, respectively performing coordinate transformation on the vertical line to obtain a first space straight line corresponding to the first suspension posture and a second space straight line corresponding to the second suspension posture comprises: Select three fixed points that are not on the same straight line from the workpiece to be measured as target measurement points; When the workpiece to be measured is in a first suspension posture, a first workpiece coordinate system corresponding to the first suspension posture is constructed based on the target measurement point, a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system is obtained, and a coordinate transformation is performed on the perpendicular line vector based on the first coordinate transformation matrix to obtain a first space straight line in the first workpiece coordinate system; When the workpiece to be measured is in the second suspension posture, a second workpiece coordinate system corresponding to the second suspension posture is constructed based on the target measurement point, and a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system is obtained. The coordinate transformation of the perpendicular line vector is performed based on the second coordinate transformation matrix to obtain a second spatial straight line in the second workpiece coordinate system.

7. The method for measuring the centroid of a workpiece according to claim 6, characterized in that: The method of constructing a first workpiece coordinate system corresponding to the first suspension posture based on the target measurement point, acquiring a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system, and performing coordinate transformation on the perpendicular line vector based on the first coordinate transformation matrix to acquire a first space straight line in the first workpiece coordinate system includes: Based on the target measurement point, a first workpiece coordinate system is acquired by fitting using a best fitting method; Acquire a first coordinate transformation matrix between the platform coordinate system and the first workpiece coordinate system according to the coordinates of the target measurement point in the first workpiece coordinate system and the coordinates of the platform coordinate system; Select any two points on the vertical line in the platform coordinate system as first coordinate transformation points, input the two first coordinate transformation points into the first coordinate transformation matrix, obtain two first space straight line coordinates in the first workpiece coordinate system, and obtain the first space straight line equation according to the first space straight line coordinates; The method of constructing a second workpiece coordinate system corresponding to the second suspension posture based on the target measurement point, acquiring a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system, and performing coordinate transformation on the perpendicular line vector based on the second coordinate transformation matrix to acquire a second space straight line in the second workpiece coordinate system includes: Based on the target measurement point, a second workpiece coordinate system is acquired by fitting using a best fitting method; Acquire a second coordinate transformation matrix between the platform coordinate system and the second workpiece coordinate system according to the coordinates of the target measurement point in the second workpiece coordinate system and the coordinates of the platform coordinate system; Select any two points on the vertical line in the platform coordinate system as second coordinate transformation points, input the two second coordinate transformation points into the second coordinate transformation matrix, obtain two second space straight line coordinates in the second workpiece coordinate system, and obtain the second space straight line equation according to the second space straight line coordinates.

8. The method for measuring the centroid of a workpiece according to claim 7, characterized in that: Determining the coordinates of the intersection of the first space straight line and the second space straight line as the coordinates of the center of mass of the workpiece to be measured includes: The first spatial straight line equation and the second spatial straight line equation are solved together to obtain the coordinates of the intersection of the first spatial straight line and the second spatial straight line, and the coordinates of the intersection are determined as the coordinates of the center of mass of the workpiece to be measured.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the computer device executes the computer program, the workpiece center of mass measurement method according to any one of claims 4 to 8 is implemented.

10. A workpiece centroid measurement system, characterized in that: It comprises the workpiece centroid measuring device according to any one of claims 1 to 3, the computer equipment, measuring instrument and coordinate digital display according to claim 9; The measuring instrument is used to measure the position information of the horizontal workbench, the calibration sphere group, the suspension assembly and the workpiece to be measured, and transmit the position information to the computer device, so that the computer device calculates the centroid coordinates of the workpiece to be measured according to the position information; The coordinate digital display is used to measure the plane coordinates of the suspension component and transmit the plane coordinates to the computer device so that the computer device determines the coordinates of the suspension point according to the plane coordinates; The computer device is used to calculate the centroid coordinates of the workpiece to be measured according to the position information.

11. The workpiece centroid measurement system according to claim 10, characterized in that: The measuring instrument is arranged on one side of the workpiece centroid measuring device, and performs non-contact measurement of the position information of the horizontal workbench, the calibration sphere group, the suspension assembly and the workpiece to be measured; The coordinate digital display is electrically connected to the X-axis coordinate grating and the Y-axis coordinate grating on the support frame; The computer device is electrically connected to the measuring instrument.

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