A dual sensor measuring system and a measuring method for ring-shaped thin-walled workpieces

Abstract

The present application belongs to the field of high-precision measurement technology, and particularly relates to a double-sensor measurement system and a measurement method for a ring-shaped thin-wall workpiece. The system comprises an XY positioning platform, an X-direction driving platform for X-direction movement, a Y-direction driving platform for Y-direction movement, a rotary table arranged on the XY positioning platform for Z-direction rotation, a manual adjustment table arranged on the rotary table and having a workpiece carrier for clamping the ring-shaped thin-wall workpiece, a Z-direction driving platform for Z-direction movement, two sensor adjusting devices mounted on the Z-direction driving platform, and two displacement sensors mounted on the sensor adjusting devices and having their optical paths aligned with each other. The present application measures the offset distance and the offset angle between the center line of the ring-shaped thin-wall workpiece and the axis of the rotary table by means of the two displacement sensors, and eliminates the offset by means of the manual adjustment table, thereby improving the measurement accuracy of the workpiece.

Description

Technical Field

[0001] This invention belongs to the field of high-precision measurement technology, specifically referring to a dual-sensor measurement system and method for annular thin-walled workpieces. Background Technology

[0002] Annular thin-walled workpieces are indispensable components in defense, aerospace, information electronics, and optical systems. The cylindricity, wall thickness variation, and morphological errors of these workpieces significantly affect system performance. Achieving accurate and stable measurement of the wall surface of annular thin-walled workpieces, thereby improving their machining precision, is a crucial means to enhance system performance.

[0003] In a single-sensor measurement system for a ring-shaped thin-walled workpiece, the positioning error of the rotary table is a significant source of error. The positioning error of the rotary table directly leads to splicing errors in the measurement data of the inner and outer walls of the ring-shaped thin-walled workpiece, making the measurement data unable to accurately reflect the wall thickness difference.

[0004] Furthermore, in a dual-sensor measurement system, the eccentricity and tilting errors of the workpiece under test, as well as the deviation of the measurement optical path of the dual sensors, directly lead to the measurement error of the annular thin-walled workpiece. This error is even more significant and critical in precision measurement systems. Therefore, effectively suppressing and resolving the eccentricity and tilting errors of the annular thin-walled workpiece, as well as the deviation of the measurement optical path of the dual sensors, through the use of dual-sensor measurement is of paramount importance for the precision measurement of annular thin-walled workpieces. Summary of the Invention

[0005] The purpose of this invention is to provide a simple and highly accurate dual-sensor measurement system and method.

[0006] The objective of this invention is achieved as follows:

[0007] A dual-sensor measurement system for annular thin-walled workpieces, comprising:

[0008] The XY positioning platform has an X-direction drive platform for movement in the X direction and a Y-direction drive platform for movement in the Y direction.

[0009] A rotary table, set on an XY positioning platform, is used for rotation in the Z direction;

[0010] A manual adjustment table, set on a rotary table, has a workpiece carrier for clamping annular thin-walled workpieces, used for fine-tuning the position of the annular thin-walled workpieces;

[0011] Z-axis drive platform, used for movement in the Z direction;

[0012] Two sensor adjustment devices, mounted on the Z-axis drive platform, are used to adjust the position of the displacement sensor; and

[0013] Two displacement sensors are mounted on the sensor adjustment device, and the optical paths of the displacement sensors are aligned with each other, for measuring the distance from the displacement sensors to the inner and outer walls of the annular thin-walled workpiece.

[0014] Preferably, the displacement sensors are chromatic confocal sensors.

[0015] Preferably, a standard ball is further included, which can be mounted on the hand adjustment table, for aligning the optical paths of the two displacement sensors.

[0016] Preferably, the hand adjustment table includes an X-direction translation fine adjustment assembly for X-direction movement, a Y-direction translation fine adjustment assembly for Y-direction movement, an X-direction tilt table for X-direction rotation, and a Y-direction tilt table for Y-direction rotation.

[0017] Preferably, the sensor adjustment device includes a Z-direction translation fine adjustment assembly for Z-direction movement, an X-direction translation fine adjustment assembly for X-direction movement, a Z-direction angle fine adjustment assembly for Z-direction rotation, and a Y-direction angle fine adjustment assembly for Y-direction rotation.

[0018] A double-sensor measurement method for an annular thin-walled workpiece, based on the above-mentioned double-sensor measurement system for an annular thin-walled workpiece, includes the following steps:

[0019] Step 1: Mount the annular thin-walled workpiece to the workpiece carrier;

[0020] Step 2: Move the XY positioning platform to move the annular thin-walled workpiece below the two displacement sensors; move the Z-direction drive platform to move the two displacement sensors to the thin wall where the horizontal section a of the annular thin-walled workpiece is located;

[0021] Step 3: Measure the annular thin-walled workpiece by controlling the rotation of the rotation table and the translation of the X-direction drive platform, and record the readings of the displacement sensors, and calculate the eccentric coordinates of the center of the annular thin-walled workpiece at the horizontal section a relative to the rotation axis of the rotation table according to the geometric relationship ( );

[0022] Step 4: Move the Z-direction drive platform to move the two displacement sensors to the thin wall where the horizontal section b of the annular thin-walled workpiece is located;

[0023] Step 5: Measure the annular thin-walled workpiece by controlling the rotation of the rotation table and the translation of the X-direction drive platform, and record the readings of the displacement sensors, and calculate the eccentric coordinates of the center of the annular thin-walled workpiece at the horizontal section b relative to the rotation axis of the rotation table according to the geometric relationship ( );

[0024] Step 6: According to the eccentric coordinates of the center of the circle at the horizontal section a and the horizontal section b, the inclination angle α of the central axis of the ring thin-walled workpiece in the YZ plane and the inclination angle β in the XZ plane are calculated, and the formula is as follows:

[0025] (1)

[0026] (2)

[0027] Step 7: According to the inclination angles α and β, the freedom of rotation of the hand-adjusting table around the X-axis and the Y-axis is adjusted respectively, so that the central axis of the ring thin-walled workpiece 106 is parallel to the rotation axis of the rotating table, and the inclination adjustment of the ring thin-walled workpiece is realized.

[0028] Step 8: The rotating table is controlled to rotate and the X-direction driving platform is controlled to translate to measure the ring thin-walled workpiece, and the chromatic confocal sensor readings are recorded, and the eccentric coordinates of the center of the circle at the horizontal section b relative to the rotation axis of the ring thin-walled workpiece are calculated according to the geometric relationship as follows: );Then, according to and the hand-adjusting table is adjusted to eliminate the eccentric distance in the X and Y directions, so that the central axis of the ring thin-walled workpiece coincides with the rotation axis of the rotating table, and the centering is realized.

[0029] Step 9: The Z-direction driving platform is controlled to translate and the rotating table is controlled to rotate to realize the spiral scanning measurement of the ring thin-walled workpiece by the double displacement sensors.

[0030] Preferably, before measuring the ring thin-walled workpiece, the light path alignment operation of the two displacement sensors is first performed:

[0031] Firstly, the standard ball is installed on the hand-adjusting table, and the standard ball is moved between the two displacement sensors by moving the X-direction driving platform, the Y-direction driving platform and the Z-direction driving platform;

[0032] Secondly, the light paths of the two displacement sensors are aligned with the center of the standard ball by adjusting the sensor adjusting device;

[0033] Finally, the standard ball is removed.

[0034] The present application has the following outstanding and beneficial technical effects compared with the prior art:

[0035] 1. The present application measures the offset distance and the offset angle between the center line of the ring thin-walled workpiece and the rotation axis of the rotating table by the two displacement sensors, and eliminates the offset distance by the hand-adjusting table, thereby improving the measurement accuracy of the workpiece.

[0036] 2, The present application uses two dispersion confocal sensors to measure the inner and outer walls of the annular thin-walled workpiece, which can improve the measurement efficiency, overcome the splicing error of the inner and outer wall measurement data in single sensor measurement, has very high measurement accuracy, and is suitable for the measurement of high-precision parts.

[0037] 3, The present application can reduce the inclination angle between the center line of the annular thin-walled workpiece and the axis of the rotating table rotating shaft to ±0.1° through the hand adjustment table, and can also reduce the eccentricity between the center line of the annular thin-walled workpiece and the axis of the rotating table rotating shaft to sub-micron level.

[0038] 4, The present application can reduce the deviation of the double-sensor measurement light path to microns through the standard ball and the sensor adjusting device, effectively improve the alignment accuracy of the detection light path, and further improve the measurement accuracy of the displacement sensor. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is the structure schematic diagram of the double-sensor measurement system of the present application.

[0040] Figure 2 It is the structure schematic diagram of the double-sensor light path alignment of the present application.

[0041] Figure 3 It is the principle schematic diagram of the centering of the annular thin-walled workpiece.

[0042] Figure 4 It is the schematic diagram of the double displacement sensor moving to the thin wall of the annular thin-walled workpiece.

[0043] Figure 5 It is the schematic diagram of the double displacement sensor for spiral scanning measurement of the annular thin-walled workpiece.

[0044] The meaning represented by the reference signs in the figure:

[0045] 101-Y direction driving mechanism;102-X direction driving mechanism;103-rotating table;104-hand adjustment installation position;105-hand adjustment table;106-annular thin-walled workpiece;107-displacement sensor;108-sensor mounting rack;109-Z direction driving platform;110-X direction inclination table;111-Y direction inclination table;112-Z direction translational fine adjustment assembly;113-X direction translational fine adjustment assembly;114-Z direction angle fine adjustment assembly;115-Y direction angle fine adjustment assembly;116-standard ball. DETAILED DESCRIPTION

[0046] The present application will be further described below in combination with specific embodiments:

[0047] For example, Figure 1As shown, a double-sensor measurement system for a ring-shaped thin-walled workpiece comprises an XY positioning platform, a rotating table 103, a manual adjustment table 105, a Z-direction driving platform 109, two sensor adjustment devices, and two displacement sensors 107.

[0048] The XY positioning platform has an X-direction driving platform 102 for X-direction movement and a Y-direction driving platform 101 for Y-direction movement, which are mainly used for the movement and positioning of the ring-shaped thin-walled workpiece. A rotating table 103 for Z-direction rotation is arranged on the XY positioning platform. The rotating table 103 is provided with a manual adjustment mounting position 104, and the manual adjustment mounting position 104 is installed with the manual adjustment table 105. The manual adjustment table 105 is provided with a workpiece carrier for clamping the ring-shaped thin-walled workpiece 106, and the manual adjustment table 105 is used for fine adjustment of the position of the ring-shaped thin-walled workpiece 106. In this embodiment, the manual adjustment table 105 is mainly used for the movement and rotation adjustment of the ring-shaped thin-walled workpiece in the X / Y direction.

[0049] The manual adjustment table 105 comprises an X-direction translation fine adjustment assembly for X-direction movement, a Y-direction translation fine adjustment assembly for Y-direction movement, an X-direction tilt table 110 for rotation around the X direction, and a Y-direction tilt table 111 for rotation around the Y direction. When the displacement sensor 107 measures the offset amount of the center axis of the ring-shaped thin-walled workpiece and the axis of the rotating table 103, this structure not only eliminates the X-direction offset amount through the X-direction translation fine adjustment assembly and the Y-direction offset amount through the Y-direction translation fine adjustment assembly, but also eliminates the spatial tilt angle of the ring-shaped thin-walled workpiece 106 through the X-direction tilt table 110 and the Y-direction tilt table 111, which is suitable for ring-shaped thin-walled workpieces 106 whose center axis is not perpendicular to the bottom surface, and ensures that the center axis of the ring-shaped thin-walled workpiece 106 coincides with the rotation axis of the rotating table 103 before measurement, so as to improve the measurement accuracy.

[0050] In this embodiment, the manual adjustment mounting position 104 is a mounting plate fixed to the bottom of the manual adjustment table 105, and the mounting plate is fixed to the rotating table 103 by screws. The workpiece carrier is a ring-shaped seat, and the bottom of the ring-shaped thin-walled workpiece 106 is installed in the inner circle of the ring-shaped seat and clamped by fasteners.

[0051] The Z-direction driving platform 109 is used for the movement and positioning of the displacement sensor 107 in the Z direction, and two sensor adjustment devices for adjusting the position of the displacement sensor 107 are symmetrically arranged on the Z-direction driving platform 109 through a sensor mounting rack 108. Each sensor adjustment device is correspondingly installed with one displacement sensor 107.

[0052] In the embodiment, the displacement sensor 107 is a chromatic confocal sensor, vertically arranged on the sensor adjusting device, and has a light source with 90° light emission. The light paths of the displacement sensor 107 are aligned with each other, for measuring the distance from the displacement sensor 107 to the inner and outer walls of the annular thin-walled workpiece 106, and for measuring the surface shape, roundness, cylindricity, etc. of the annular thin-walled workpiece 106, with the precision of nm level.

[0053] Specifically, the Z-direction driving platform 109 is symmetrically provided with a sensor adjusting device for adjusting the position of the displacement sensor 107, which includes a Z-direction translational fine adjustment assembly 112 for Z-direction movement, an X-direction translational fine adjustment assembly 113 for X-direction movement, a Z-direction angle fine adjustment assembly 114 for Z-direction rotation, and a Y-direction angle fine adjustment assembly 115 for Y-direction rotation. The sensor adjusting device can adjust the position of the displacement sensor 107 in the Z / X direction and the angle of the displacement sensor 107 in the Z / Y direction, facilitating the adjustment of the light path of the displacement sensor 107.

[0054] The embodiment is also provided with a standard ball 116 with a diameter of 8 mm and a machining precision of 30 nm, which is detachably installed on the hand adjustment table 105.

[0055] Before measurement, the standard ball 116 is installed on the hand adjustment table 105, the position of the standard ball 116 is adjusted by the X-direction driving platform 102, the Y-direction driving platform 101 and the Z-direction driving platform 109, and the light path position of the displacement sensor 107 is adjusted by the sensor adjusting device. When the light path of the displacement sensor 107 is aligned with the center of the standard ball 116, the light path is aligned. After the light path is aligned, the standard ball 116 is removed.

[0056] In the embodiment, the X-direction driving platform 102, the Y-direction driving platform 101 and the Z-direction driving platform 109 each include a servo motor, a screw transmission structure and a sliding table. The servo motor drives the sliding table to move linearly through the screw transmission structure. Generally, the stroke is within 1000 mm, and the precision is in the order of μm.

[0057] The structures of the X-direction translational fine adjustment assembly, the Y-direction translational fine adjustment assembly, the Z-direction translational fine adjustment assembly 112 and the X-direction translational fine adjustment assembly 113 are similar to those of the driving platform. Generally, the hand control screw transmission structure drives the sliding table to move linearly, with the stroke in the order of mm and the adjustment precision in the order of μm.

[0058] The structures of the X-direction tilt table 110, the Y-direction tilt table 111, the Z-direction angle fine adjustment assembly 114, and the Y-direction angle fine adjustment assembly 115 are similar, and each includes a mounting seat provided with an arc-shaped groove, a rotating block provided with an arc-shaped bottom surface, and a fine adjustment assembly. The rotating block is rotatably arranged on the mounting seat through the fine adjustment assembly, so that the rotating block can rotate around the axis of the arc-shaped groove, thereby realizing angle adjustment. The angle adjustment range is ±10°, and the adjustment accuracy is 0.01°.

[0059] A double-sensor measurement method for a ring-shaped thin-walled workpiece, based on the above-mentioned double-sensor measurement system for a ring-shaped thin-walled workpiece.

[0060] Before measuring the ring-shaped thin-walled workpiece 106, first, the light path alignment operation of the two displacement sensors 107 is performed:

[0061] First, install the standard ball 116 on the hand adjustment table 105, and move the standard ball 116 between the two displacement sensors by moving the X-direction driving platform 102, the Y-direction driving platform 101, and the Z-direction driving platform 109. Second, adjust the Y-direction freedom of the sensor adjustment device so that the standard ball 116 is within the range of the two displacement sensors; then adjust the X and Z direction freedom of the sensor adjustment device so that the light paths of the two displacement sensors 107 are aligned with the center of the standard ball 116. As shown in Figure 2 , the light path alignment of the two displacement sensors 107 is realized, and the standard ball 116 is removed at this time.

[0062] Then the centering and detection of the ring-shaped thin-walled workpiece are started, which includes the following steps:

[0063] First step: install the ring-shaped thin-walled workpiece 106 to the workpiece carrier;

[0064] Second step: move the XY positioning platform to move the ring-shaped thin-walled workpiece 106 to the bottom of the two displacement sensors 107; then move the Z-direction driving platform 109 to move the two displacement sensors 107 to the thin wall where the horizontal cross section a of the bottom ring-shaped thin-walled workpiece 106 is located, as shown in Figure 3 ;

[0065] Third step: measure the ring-shaped thin-walled workpiece 106 by controlling the rotation of the rotating table 103 and the translation of the X-direction driving platform 102, and record the readings of the displacement sensors 107, and calculate the eccentric coordinates of the center of the ring-shaped thin-walled workpiece 106 at the horizontal cross section a relative to the rotation axis of the rotating table 103 according to the geometric relationship ;

[0066] Fourth step: move the Z-direction driving platform 109 to move the two displacement sensors 107 to the thin wall where the horizontal cross section b of the top ring-shaped thin-walled workpiece 106 is located.​

[0067] Fifth step: measure the ring thin-walled workpiece 106 by controlling the rotation of the rotating table 103 and the translation of the X-direction driving platform 102, and record the reading of the displacement sensor 107, and calculate the eccentricity coordinate of the center of the ring thin-walled workpiece 106 at the horizontal section b relative to the rotation axis of the rotating table 103 according to the geometric relationship

[0068] Sixth step: calculate the inclination angle α of the central axis of the ring thin-walled workpiece 106 in the YZ plane and the inclination angle β in the XZ plane according to the eccentricity coordinates of the center of the ring thin-walled workpiece 106 at the horizontal section a and the horizontal section b, and the formulas are as follows:

[0069] (1)

[0070] (2)

[0071] Seventh step: adjust the freedom of the hand-adjusting table 105 rotating around the X-axis and the Y-axis respectively according to the inclination angles α and β, so that the central axis of the ring thin-walled workpiece 106 is parallel to the rotation axis of the rotating table 103, and realize the inclination angle adjustment of the ring thin-walled workpiece 106.

[0072] Eighth step: measure the ring thin-walled workpiece 106 by controlling the rotation of the rotating table 103 and the translation of the X-direction driving platform 102, and record the reading of the chromatic confocal sensor 108, and calculate the eccentricity coordinate of the center of the ring thin-walled workpiece 106 at the horizontal section b relative to the rotation axis according to the geometric relationship ; the rotation axis of the rotating table 103 is the reference system of the X / Y origin, so according to and adjust the hand-adjusting table 105, which can eliminate the eccentric distance in the X and Y directions, and further make the central axis of the ring thin-walled workpiece 106 coincide with the rotation axis of the rotating table 103, and realize the centering.

[0073] Ninth step: as shown in Figure 4 , move the double displacement sensors to the thin-walled measurement starting point of the ring thin-walled workpiece 106; as shown in Figure 5 , control the translation of the Z-direction driving platform 109 and the rotation of the rotating table 103 to realize the spiral scanning measurement of the double displacement sensors on the ring thin-walled workpiece 106.

[0074] The above embodiments are only the preferred embodiments of the present application, and do not limit the protection scope of the present application, so: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.​​

Claims

1. A double sensor measurement method for a thin-walled annular workpiece, characterized in that, a double sensor measurement system for a thin-walled annular workpiece, the double sensor measurement system comprising: an XY positioning platform having an X-direction driving platform (102) for X-direction movement and a Y-direction driving platform (101) for Y-direction movement; a rotary table (103) disposed on the XY positioning platform for Z-direction rotation; a manual adjustment table (105) disposed on the rotary table (103) and having a workpiece carrier clamping the thin-walled annular workpiece (106) for fine adjustment of the position of the thin-walled annular workpiece (106); a Z-direction driving platform (109) for Z-direction movement; two sensor adjustment devices mounted on the Z-direction driving platform (109) for adjusting the position of the displacement sensors (107); and two displacement sensors (107) mounted on the sensor adjustment devices and having their optical paths aligned with each other for measuring the distance from the displacement sensors (107) to the inner and outer walls of the thin-walled annular workpiece (106); wherein the manual adjustment table (105) comprises an X-direction translational fine adjustment assembly for X-direction movement, a Y-direction translational fine adjustment assembly for Y-direction movement, an X-direction tilt table (110) for rotation about the X-direction, and a Y-direction tilt table (111) for rotation about the Y-direction; wherein the sensor adjustment devices comprise a Z-direction translational fine adjustment assembly (112) for Z-direction movement, an X-direction translational fine adjustment assembly (113) for X-direction movement, a Z-direction angular fine adjustment assembly (114) for rotation about the Z-direction, and a Y-direction angular fine adjustment assembly (115) for rotation about the Y-direction; the double sensor measurement method comprising the following steps: first step: mounting the thin-walled annular workpiece (106) to the workpiece carrier; second step: moving the XY positioning platform to move the thin-walled annular workpiece (106) below the two displacement sensors (107); moving the Z-direction driving platform (109) to move the two displacement sensors (107) to the thin wall where the horizontal section a of the thin-walled annular workpiece (106) is located; Third step: measure the ring-shaped thin-walled workpiece (106) by controlling the rotation of the rotating table (103) and the translation of the X-direction driving platform (102), and record the reading of the displacement sensor (107), and calculate the eccentric coordinates of the center of the ring-shaped thin-walled workpiece (106) at the horizontal section a relative to the rotation axis of the rotating table (103) according to the geometric relationship ( ) fourth step: moving the Z-direction driving platform (109) to move the two displacement sensors (107) to the thin wall where the horizontal section b of the thin-walled annular workpiece (106) is located; Fifth step: measure the annular thin-walled workpiece (106) by controlling the rotation of the rotating table (103) and the translation of the X-direction driving platform (102), and record the reading of the displacement sensor (107), and calculate the eccentric coordinates of the center of the annular thin-walled workpiece (106) at the horizontal section b relative to the rotation axis of the rotating table (103) according to the geometric relationship ( ) sixth step: calculating the inclination angle a of the central axis of the thin-walled annular workpiece (106) in the YZ plane and the inclination angle β in the XZ plane according to the eccentric coordinates of the center of the horizontal sections a and b, as follows: （1） （2） seventh step: adjusting the degrees of freedom of the manual adjustment table (105) for rotation about the X-axis and Y-axis according to the inclination angles a and β, so that the central axis of the thin-walled annular workpiece (106) is parallel to the rotation axis of the rotary table (103), and the inclination adjustment of the thin-walled annular workpiece (106) is realized; The eighth step: control the rotation of the rotating table (103) and the translation of the X-direction driving platform (102) to measure the annular thin-walled workpiece (106), and record the reading of the displacement sensor (107), and calculate the eccentricity coordinate of the center of the annular thin-walled workpiece (106) at the horizontal section b relative to the rotation axis as ); then adjust the manual adjustment table (105) according to and , so as to eliminate the eccentric distance in the X and Y directions, and then make the center axis of the annular thin-walled workpiece (106) coincide with the rotation axis of the rotating table (103), and realize the centering.

2. A method for measuring a ring-shaped thin-walled workpiece with two sensors according to claim 1, characterized in that: the displacement sensors (107) are dispersive confocal sensors.

3. A method for measuring a ring-shaped thin-walled workpiece with two sensors according to claim 1, characterized in that: a standard sphere (116) is further included and can be mounted on the manual adjustment table (105) for alignment of the optical paths of the two displacement sensors (107).

4. A method for measuring a double sensor for a ring-shaped thin-walled workpiece according to claim 1, characterized in that, Also includes the ninth step: the need to control the Z direction drive platform (109) translation and rotation platform (103) to achieve two displacement sensor ring thin wall workpiece (106) spiral scanning measurement.

5. A method for measuring a ring-shaped thin-walled workpiece according to claim 1, wherein Before measuring the ring thin wall workpiece (106), first of all, the two displacement sensor (107) light path alignment operation: First, the standard ball (116) is installed on the hand table (105), by moving the X direction drive platform (102), Y direction drive platform (101) and Z direction drive platform (109), so that the standard ball (116) moves to the two displacement sensor (107) between; Second, by adjusting the sensor adjusting device, the light path of the two displacement sensor (107) is aligned with the center of the standard ball (116); Finally, remove the standard ball (116).

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