A method for measuring the linear repeat positioning accuracy of a filament winding machine

Abstract

The present invention provides a method for measuring the linear repeat positioning accuracy of a fiber winding machine. The steps include: drawing a winding trajectory, installing a calibration hemisphere on the winding trajectory, obtaining the maximum height difference h1 of the indication of the dial indicator during the first crossing of the calibration hemisphere and the maximum height difference h2 of the indication of the dial indicator during the Nth crossing of the calibration hemisphere, and calculating the horizontal distance S between the center of the measuring ball of the dial indicator corresponding to the maximum height difference h1 and the center of the measuring ball of the dial indicator corresponding to the maximum height difference h2, which is the linear repeat positioning accuracy. The present invention can accurately, quickly and simply achieve the measurement of the linear repeat positioning accuracy. The operation process is simple and easy to implement. Ordinary operators can operate smoothly. It can be applied to measure the linear repeat positioning accuracy in processes such as fiber placement, fiber tape laying, and 3D printing.

Description

Technical Field

[0001] The present invention relates to the technical field of debugging of fiber winding composite material manufacturing equipment, and particularly relates to a method for measuring the linear repeat positioning accuracy of a fiber winding machine. Background Art

[0002] Continuous fiber reinforced composites have the advantages of high specific strength, low specific gravity, and in-situ curing, etc., and are increasingly widely used in the fields of aerospace, weaponry, etc., and are gradually becoming new materials to replace traditional polymers, thermosetting composites, and metals. The fiber winding process has cost and efficiency advantages that cannot be compared with other composite material forming methods in the preparation of various pipelines, pressure vessels, etc. Its forming process is mainly divided into two steps: guiding the yarn and heating and winding. The fiber yarn is fed into the yarn guiding device by the yarn feeding roller, led out from the nozzle, and finally the movement of the nozzle drives the fiber to be arranged on the mandrel according to the set trajectory to complete the winding process. The linear repeat positioning accuracy determines the forming accuracy of the winding trajectory, directly affects the performance of the wound parts, and too low accuracy will lead to uncontrollable spacing between adjacent fiber bundles, resulting in fiber stacking or gap arrangement. Only when the linear repeat positioning accuracy is high can products with high surface quality, high strength, and high fatigue resistance be produced.

[0003] At present, the measurement of the linear repeat positioning accuracy of fiber winding machines is mainly carried out by scribing inspection. The first method is to install a fine scriber on the winding trolley. After the winding program starts, the scriber scribes on the surface of the mold to check the deviation of the scribing position during repeated winding. The second method is to lay paper on the surface and use a ballpoint pen with a flexible reverse fixture to scribe lines to check the deviation of the handwriting position during repeated winding. The first method belongs to a destructive test, which will damage the surface of the mold and is not applicable to high-precision molds with high costs. The handwriting width of the second method generally exceeds 0.5 mm, while the general linear accuracy of winding is 0.1 mm, which is not applicable to winding forming that requires high linear accuracy. In addition, the above two methods have common drawbacks, that is, they cannot accurately and low-costly measure the linear repeat positioning accuracy using existing fiber winding machines, and the existing methods seriously rely on the skill level of operators, with disadvantages such as large measurement errors and low measurement efficiency. Summary of the Invention

[0004] To at least solve one or more of the problems mentioned in the background art, the object of the present invention is to provide a method for measuring the linear repeat positioning accuracy of a fiber winding machine.

[0005] To achieve the above object, the present invention adopts the following technical solutions.

[0006] A method for measuring the linear repeat positioning accuracy of a fiber winding machine, the steps include:

[0007] Step 1: Draw a winding trajectory according to the actual winding path. All subsequent windings shall be carried out based on this winding trajectory. Completing one layer of winding means running from the starting point to the ending point of the winding trajectory.

[0008] Step 2: Install a calibration hemisphere at the center line of a specified position on the winding trajectory.

[0009] Step 3: Fix a dial indicator with a probe radius of r at the wire outlet of the fiber winding machine. Run the fiber winding machine to complete a single-layer winding for the first time, and obtain the maximum height difference Δh1 of the dial indicator reading during the first crossing of the calibration hemisphere.

[0010] Step 4: Continue to run the fiber winding machine, wind again or continuously for multiple times, and obtain the maximum height difference Δh2 of the dial indicator reading during the Nth crossing of the calibration hemisphere.

[0011] Step 5: Calculate the horizontal distance S between the center of the dial indicator probe corresponding to the maximum height difference Δh1 and the center of the dial indicator probe corresponding to the maximum height difference Δh2. This horizontal distance S is the linear repeat positioning accuracy.

[0012] Preferably, Step 1 specifically includes: first set the winding path program, then fix a marker pen on the wire outlet of the winding carriage, and then run the winding path program to draw the winding trajectory on the surface of the mandrel with the marker pen.

[0013] To further improve the accuracy of the measurement result of the linear repeat positioning accuracy, Step 2 specifically includes: select a suitable calibration hemisphere with a radius of R, fix the calibration hemisphere at a specified position on the winding trajectory, and ensure that the center of the calibration hemisphere coincides with the center line of the specified position on the winding trajectory.

[0014] To further improve the accuracy of the measurement result of the linear repeat positioning accuracy, Step 3 specifically includes: first replace the marker pen with a dial indicator, then adjust the position of the dial indicator so that the probe of the dial indicator is located at the junction of the edge of the calibration hemisphere and the mandrel and contacts the surface of the mandrel, and then perform a zeroing operation on the dial indicator; then run the fiber winding machine to complete a single-layer winding, and record the maximum height difference Δh1 of the dial indicator reading during the first crossing of the calibration hemisphere.

[0015] Preferably, in Step 4, wind continuously for 3 - 5 times, and use the average value or the maximum value of the maximum height difference of the readings as the maximum height difference Δh2.

[0016] Preferably, fix the calibration hemisphere at the center line of a specified position on the winding trajectory by means of bonding or threaded connection.

[0017] Preferably, the radius of the calibration hemisphere is not greater than 10 mm. More preferably, the radius of the calibration hemisphere is 1 mm - 2 mm.

[0018] In the present invention:

[0019] When the maximum height difference -h1 corresponds to the vertex and is inside or outside relative to the maximum height difference -h2, the linear repeat positioning accuracy is calculated using Equation (Ⅰ). ;

[0020] …………… (Ⅰ)

[0021] When the maximum height difference -h2 corresponds to the vertex and is inside or outside relative to the maximum height difference -h1, the linear repeat positioning accuracy is calculated using Equation (Ⅱ). ;

[0022] …………… (Ⅱ)

[0023] When both the maximum height difference -h1 and the maximum height difference -h2 correspond to the same side of the vertex, the linear repeat positioning accuracy AD is calculated using Equation (Ⅲ);

[0024] ……… (Ⅲ)

[0025] When both the maximum height difference -h1 and the maximum height difference -h2 correspond to both sides / different sides (opposite sides) of the vertex, the linear repeat positioning accuracy AD' is calculated using Equation (Ⅳ);

[0026] ……… (Ⅳ)

[0027] In the formula, R represents the radius of the calibration hemisphere, and r represents the radius of the probe of the dial indicator.

[0028] In order to more accurately, quickly, and simply achieve the measurement of the linear repeat positioning accuracy, a controller is further included. The controller is connected to the fiber optic amplifier and the vision system. The vision system is used to identify the reading of the dial indicator. A fiber optic sensor adapted to the fiber optic amplifier is installed on the side of the calibration hemisphere. And when the probe of the dial indicator moves to the plane of the central cross-section of the calibration hemisphere perpendicular to the center line, the sensing light emitted by the fiber optic sensor just acts on the rod body of the dial indicator; The controller includes a memory, a processor, and a program stored on the memory and executable on the processor. When the processor executes the program, the following steps / functions are implemented:

[0029] S1, when the probe of the dial indicator moves to the plane of the central cross-section of the calibration hemisphere perpendicular to the center line, the fiber optic sensor senses the rod body of the dial indicator and feeds the sensing signal back to the controller through the fiber optic amplifier;

[0030] S2. At the moment when the controller receives the induction signal, obtain the reading of the dial indicator through the vision system;

[0031] S3. Determine the relative position of the dial indicator rod according to the obtained induction signal (substantially the horizontal distance / value corresponding to the induction signal);

[0032] S4. Call the corresponding calculation model according to the obtained reading and relative position, calculate and output the linear repeat positioning accuracy.

[0033] Furthermore, in step S3: Define the horizontal distance corresponding to the induction signal obtained when the calibration hemispherical probe is located at the vertex of the calibration hemisphere as the preset threshold; (1) When the fiber optic amplifier is installed on the right side of the calibration hemisphere, if the horizontal distance corresponding to the obtained induction signal is greater than the preset threshold, it means that the dial indicator rod is located on the left side of the vertex of the calibration hemisphere, and if the horizontal distance corresponding to the obtained induction signal is less than the preset threshold, it means that the dial indicator rod is located on the right side of the vertex of the calibration hemisphere; or, (2) When the fiber optic amplifier is installed on the left side of the calibration hemisphere, if the horizontal distance corresponding to the obtained induction signal is greater than the preset threshold, it means that the dial indicator rod is located on the right side of the vertex of the calibration hemisphere, and if the horizontal distance corresponding to the obtained induction signal is less than the preset threshold, it means that the dial indicator rod is located on the left side of the vertex of the calibration hemisphere.

[0034] Beneficial effects: The present invention measures the linear repeat positioning accuracy by means of the calibration hemisphere and the dial indicator, which belongs to non-destructive measurement, and can effectively avoid the deficiencies such as large measurement errors and low measurement efficiency existing in the existing manual scribing inspection method, and can greatly improve the measurement accuracy of the linear repeat positioning accuracy; The present invention uses the calibration hemisphere as the measurement reference, and its size can be flexibly changed according to the size of the mandrel, and the measurement position can be flexibly set, expanding the application scope of the present invention; The present invention can accurately, quickly and simply realize the measurement of the linear repeat positioning accuracy, the operation process is simple, easy to implement, and ordinary operators can operate smoothly; The present invention can be applied to measure the linear repeat positioning accuracy in processes such as fiber placement, fiber tape laying, and 3D printing. Description of the Drawings

[0035] Figure 1 is a schematic diagram of the winding trajectory drawn in the embodiment;

[0036] Figure 2 is a schematic diagram of the installation position of the calibration hemisphere in the embodiment, and the cross-sectional position in the figure represents the plane where the central cross-section of the calibration hemisphere perpendicular to the center line of the specified position on the winding trajectory is located;

[0037] Figure 3Schematic diagrams of three different relative position relationships of the dial indicator in the embodiments: (a) vertex position, (b) same-side position, (c) different-side position. In the figures, the three dial indicator rods (from left to right) respectively represent the zero-adjusted state of the dial indicator, the state when the maximum height difference -h1 occurs during the first crossing of the calibration hemisphere 3 by the dial indicator, and the state when the maximum height difference -h2 occurs during the Nth crossing of the calibration hemisphere 3 by the dial indicator;

[0038] Figure 4 It is the state in the embodiment where the maximum height difference -h1 corresponds to the vertex and is on the outer side (the right side in the figure) relative to the maximum height difference -h2;

[0039] Figure 5 It is the state in the embodiment where the maximum height difference -h1 corresponds to the vertex and is on the inner side relative to the maximum height difference -h2;

[0040] Figure 6 It is the state in the embodiment where the maximum height difference -h2 corresponds to the vertex and is on the outer side relative to the maximum height difference -h1;

[0041] Figure 7 It is the state in the embodiment where the maximum height difference -h2 corresponds to the vertex and is on the inner side relative to the maximum height difference -h1;

[0042] Figure 8 It is the state in the embodiment where both the maximum height difference -h1 and the maximum height difference -h2 correspond to the same side of the vertex;

[0043] Figure 9 It is the state in the embodiment where the maximum height difference -h1 and the maximum height difference -h2 correspond to different sides (opposite sides) of the vertex;

[0044] Figures 10 - 12 It is the state in Embodiment 2 where the sensing light emitted by the fiber optic sensor just acts on the rod body of the dial indicator. Detailed implementation manners

[0045] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. However, the description of the following embodiments is only used to help understand the principle and core idea of the present invention, and does not limit the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, improvements made to the present invention without departing from the principle of the present invention also fall within the protection scope of the claims of the present invention.

[0046] Embodiment 1

[0047] A method for measuring the linear repetitive positioning accuracy of a fiber winding machine, the steps including:

[0048] Step 1, draw the winding trajectory 2 according to the actual winding path;

[0049] Specifically: First, set the winding path program. Then, fix the marker pen on the wire outlet of the winding trolley. Next, run the winding path program, and use the marker pen to draw the winding trajectory 2 on the surface of the mandrel 1, as Figure 1 shown;

[0050] Subsequent winding is carried out according to this winding trajectory 2. Completing one layer of winding means running from the starting point to the end point of the winding trajectory 2;

[0051] Step 2: Install the calibration hemisphere 3 at the center line of the specified position on the winding trajectory 2;

[0052] Specifically: Select a suitable calibration hemisphere 3 according to the size of the mandrel 1. The radius of the calibration hemisphere 3 is R. Fix (bond) the calibration hemisphere 3 at the specified position on the winding trajectory 2, as Figure 2 shown, and ensure that the center of the calibration hemisphere 3 coincides with the center line of the specified position on the winding trajectory 2, and the bottom surface of the calibration hemisphere 3 is completely attached to the surface of the mandrel 1;

[0053] Step 3: Fix the dial indicator with a radius of r at the wire outlet of the filament winding machine. Run the filament winding machine to complete the first single-layer winding for the first time, that is, simulate winding a layer of wire along the winding trajectory 2, and obtain the maximum height difference -h1 of the dial indicator reading during the first crossing of the calibration hemisphere 3;

[0054] Specifically: First, replace the marker pen with the dial indicator, then adjust the position of the dial indicator so that the measuring head 4 of the dial indicator is located at the intersection of the edge of the calibration hemisphere 3 and the mandrel 1 and contacts the surface of the mandrel 1, and then perform a zeroing operation on the dial indicator; then run the filament winding machine to complete the single-layer winding, and record the maximum height difference -h1 of the dial indicator reading during the first crossing of the calibration hemisphere 3.

[0055] Step 4: Continue to run the filament winding machine, perform winding again, and obtain the maximum height difference -h2 of the dial indicator reading during the second crossing of the calibration hemisphere 3;

[0056] Step 5: Calculate the horizontal distance S between the center of the measuring head 4 of the dial indicator corresponding to the maximum height difference -h1 and the center of the measuring head 4 of the dial indicator corresponding to the maximum height difference -h2. This horizontal distance S is the linear repeat positioning accuracy;

[0057] As Figure 3 shown, it represents a schematic diagram of three different positional relationships of the dial indicator when the height differences are h1 and h2 respectively, Figure 3Part (a) shows that the dial indicator probe 4 is located at the vertex. At this time, h1 = R or h2 = R or h1 = h2 = R. The dial indicator probe 4 passes through the vertex of the calibration hemisphere 3. This situation is called the vertex position. Part (b) shows that the dial indicator probe 4 is located on the same side of the vertex. Part (c) shows that the dial indicator probe 4 is located on the opposite side of the vertex; during the measurement process, when the dial indicator probe 4 moves to the plane of the central cross-section of the calibration hemisphere 3 perpendicular to the center line (the center line at the specified position on the winding track 2, that is, the center line of the winding track 2 where the calibration hemisphere 3 is installed), the readings are h1 and h2 respectively. At this time, h1, h2 and the vertex are in the same plane; Figure 2 the interface position in

[0058] Next, the calculation models for several situations will be described respectively. R represents the radius of the calibration hemisphere 3, and r represents the radius of the dial indicator probe 4, as follows: (1)

[0060] When the maximum height difference - h1 corresponds to the vertex and is outside relative to the maximum height difference - h2, as Figure 4 shown, in this case, the center distance between the calibration hemisphere 3 and the dial indicator probe 4 at height differences h1 and h2 is O2O 32 = R + r. The vertical distance between the dial indicator probe 4 not at the vertex position of the calibration hemisphere 3 and the zero position of the dial indicator is DO 32 = r + h2; then the horizontal distance between the dial indicator probes 4 at height differences h1 and h2 is , and this formula is defined as formula (Ⅰ) or calculation model (Ⅰ);

[0061] When the maximum height difference - h1 corresponds to the vertex and is inside relative to the maximum height difference - h2, as Figure 5 shown, in this case, the center distance between the calibration hemisphere 3 and the dial indicator probe 4 at height differences h1 and h2 is O2O 32 = R + r. The vertical distance between the dial indicator probe 4 not at the vertex position of the calibration hemisphere 3 and the zero position of the dial indicator is DO 32 = r + h2; then the horizontal distance between the dial indicator probes 4 at height differences h1 and h2 is , and this formula is defined as formula (Ⅰ) or calculation model (Ⅰ);

[0062] When the maximum height difference - h2 corresponds to the vertex and is outside relative to the maximum height difference - h1, as Figure 6 shown, in this case, the center distance between the calibration hemisphere 3 and the dial indicator probe 4 at height differences h1 and h2 is O2O 31 = R + r. The vertical distance between the dial indicator probe 4 not at the vertex position of the calibration hemisphere 3 and the zero position of the dial indicator is AO 31= r + h1; then the horizontal distance between the dial gauge probes 4 when the height differences are h1 and h2 respectively is , and this equation is defined as Equation (II) or calculation model (II);

[0063] When the maximum height difference h2 corresponds to the vertex and is inside relative to the maximum height difference h1, as Figure 7 shown, in this case, the center distance between the calibration hemisphere 3 and the dial gauge probes 4 when the height differences are h1 and h2 respectively is O2O 31 = R + r, and the vertical distance between the dial gauge probe 4 not at the vertex position of the calibration hemisphere 3 and the dial gauge zero position is AO 31 = r + h1; then the horizontal distance between the dial gauge probes 4 when the height differences are h1 and h2 respectively is , and this equation is defined as Equation (II) or calculation model (II); (2)

[0065] When both the maximum height difference h1 and the maximum height difference h2 correspond to the same side of the vertex, as Figure 8 shown, in this case, the center distance between the calibration hemisphere 3 and the dial gauge probes 4 when the height differences are h1 and h2 respectively is O2O 31 = R + r, O2O 32 = R + r, and the vertical distance between the dial gauge probe 4 not at the vertex position of the calibration hemisphere 3 and the dial gauge zero position is AO 31 = r + h1, DO 32 = r + h2; then the horizontal distance between the dial gauge probes 4 when the height differences are h1 and h2 respectively and the center O2 of the calibration hemisphere 3 is , ;

[0066] Then the horizontal distance between the dial gauge probes 4 when the height differences are h1 and h2 respectively is , and this equation is defined as Equation (III) or calculation model (III); (3)

[0068] When both the maximum height difference h1 and the maximum height difference h2 correspond to different sides of the vertex (on different sides), as Figure 9 shown, in this case, the center distance between the calibration hemisphere 3 and the dial gauge probes 4 when the height differences are h1 and h2 respectively is O2O 31 = R + r, O2O 32 = R + r, and the vertical distance between the dial gauge probe 4 not at the vertex position of the calibration hemisphere 3 and the dial gauge zero position is AO 31 = r + h1, DO 32 = r + h2; then the horizontal distance between the dial gauge probes 4 when the height differences are h1 and h2 respectively and the center O2 of the calibration hemisphere 3 is , When the height differences are h1 and h2 respectively, the horizontal distance between the dial indicator probes 4 is , and this formula is defined as formula (IV) or calculation model (IV); for the convenience of distinguishing from the horizontal distance in item (3) which is , in this item is defined as AD’, that is, AD’ .

[0069] In an application case, the diameter of the core mold 1 is 3000 mm. A calibration hemisphere 3 with a suitable size is made according to the size of the core mold 1 so that it completely fits the surface of the core mold 1. The radius R of the calibration hemisphere 3 is 2 mm, and the radius r of the dial indicator probe 4 used is 1 mm. When implementing step 3, the maximum height difference -h1 during the dial indicator moving forward across the calibration hemisphere 3 is 0.12 mm; when implementing step 4, the measured maximum height difference two h2 is 0.26 mm.

[0070] Combined with the observation of the operator, it is known that the relative position relationship of the dial indicator when the readings are h1 and h2 respectively is the same side position as shown in Figure 8 . In this case, the spherical center distance between the calibration hemisphere 3 and the dial indicator probes 4 when the height differences are h1 and h2 respectively is O2O 31 =R + r = 2 + 1 = 3 mm, O2O 32 =R + r = 2 + 1 = 3 mm. The vertical distance between the dial indicator probe 4 not at the vertex position of the calibration hemisphere 3 and the zero position of the dial indicator is AO 31 =r + h 1= 1 + 0.12 = 1.12 mm, DO 32 =r + h2 = 1 + 0.26 = 1.26 mm; then the horizontal distance between the dial indicator probes 4 and the spherical center O2 of the calibration hemisphere 3 when the height differences are h1 and h2 respectively is

[0071] = ,

[0072] = ;

[0073] Then the horizontal distance between the dial indicator probes 4 when the height differences are h1 and h2 respectively is = , that is, the linear repeat positioning accuracy in this test case is 0.0605 mm.

[0074] Example 2

[0075] A method for measuring the linear repeat positioning accuracy of a fiber winding machine, the steps include:

[0076] Step 1: Draw the winding trajectory 2 according to the actual winding path;

[0077] Specifically: First, set the winding path program, then fix a marker pen on the wire outlet of the winding trolley, and then run the winding path program. Use the marker pen to draw the winding trajectory 2 on the surface of the mandrel 1, as Figure 1 shown;

[0078] Subsequent winding is carried out according to this winding trajectory 2. Completing one layer of winding means running from the starting point to the end point of the winding trajectory 2;

[0079] Step 2: Install the calibration hemisphere 3 at the center line of the specified position on the winding trajectory 2;

[0080] Specifically: Select a suitable calibration hemisphere 3 according to the size of the mandrel 1. The radius of the calibration hemisphere 3 is R. Fix (bond) the calibration hemisphere 3 at the specified position on the winding trajectory 2, as Figure 2 shown, and ensure that the center of the calibration hemisphere 3 coincides with the center line of the specified position on the winding trajectory 2, and the bottom surface of the calibration hemisphere 3 completely fits the surface of the mandrel 1;

[0081] Step 3: Fix a micrometer with a radius of r at the wire outlet of the filament winding machine, run the filament winding machine to complete the first single-layer winding for the first time, that is, simulate winding a layer of silk along the winding trajectory 2, and obtain the maximum height difference Δh1 of the micrometer reading during the first crossing of the calibration hemisphere 3;

[0082] Specifically: First, replace the marker pen with a micrometer, then adjust the position of the micrometer so that the measuring head 4 of the micrometer is located at the intersection of the edge of the calibration hemisphere 3 and the mandrel 1 and contacts the surface of the mandrel 1, and then perform a zeroing operation on the micrometer; then run the filament winding machine to complete the single-layer winding, and record the maximum height difference Δh1 of the micrometer reading during the first crossing of the calibration hemisphere 3.

[0083] Step 4: Continue to run the filament winding machine, wind again, and obtain the maximum height difference Δh2 of the micrometer reading during the second crossing of the calibration hemisphere 3;

[0084] Step 5: Calculate the horizontal distance S between the center of the ball of the micrometer measuring head 4 corresponding to the maximum height difference Δh1 and the center of the ball of the micrometer measuring head 4 corresponding to the maximum height difference Δh2. This horizontal distance S is the linear repeat positioning accuracy;

[0085] As Figure 3 shown, it represents a schematic diagram of three different positional relationships of the micrometer when the height differences are Δh1 and Δh2 respectively, Figure 3Part (a) therein indicates that the dial indicator probe 4 is located at the vertex. At this time, h1 = R or h2 = R or h1 = h2 = R. The dial indicator probe 4 passes through the vertex of the calibration hemisphere 3. This situation is called the vertex position. Part (b) indicates that the dial indicator probe 4 is located on the same side of the vertex. Part (c) indicates that the dial indicator probe 4 is located on the opposite side of the vertex. During the measurement process, when the dial indicator probe 4 moves to the plane of the central cross-section of the calibration hemisphere 3 perpendicular to the center line (the center line at the specified position on the winding track 2, that is, the center line of the winding track 2 where the calibration hemisphere 3 is installed), the readings are h1 and h2 respectively. At this time, h1, h2 and the vertex are in one plane.

[0086] In this embodiment, a controller is also provided. The controller is connected to the fiber optic amplifier and the vision system (the image acquisition end of the vision system uses a high-precision camera, and the lens of the high-precision camera is directly facing the dial of the dial indicator). The vision system is used to identify the reading of the dial indicator. The fiber optic sensor adapted to the fiber optic amplifier is installed on the side of the calibration hemisphere 3. Specifically, the fiber optic sensor is installed at Figure 2 the cross-section position in and makes the induction light emitted by the fiber optic sensor coincide with this cross-section. And when the dial indicator probe 4 moves to the plane of the central cross-section of the calibration hemisphere 3 perpendicular to the center line (the center line at the specified position on the winding track 2, that is, the center line of the winding track 2 where the calibration hemisphere 3 is installed), the induction light emitted by the fiber optic sensor ( Figures 10 - 12 indicated by labels ① and ② in) just acts on the rod body of the dial indicator. More precisely, the induction light just acts on the axis of the rod body of the dial indicator. The controller includes a memory, a processor, and a program stored on the memory and executable on the processor. When the processor executes the program, the following steps / functions are realized:

[0087] S1, when the dial indicator probe 4 moves to the plane of the central cross-section of the calibration hemisphere 3 perpendicular to the center line, the fiber optic sensor senses the rod body of the dial indicator, that is, the induction light emitted by the fiber optic sensor just enters the rod body of the dial indicator, and feeds the induction signal back to the controller through the fiber optic amplifier.

[0088] S2, at the moment when the controller receives the induction signal, it obtains the reading of the dial indicator through the vision system.

[0089] S3, determine the relative position of the rod body of the dial indicator according to the obtained induction signal.

[0090] By defining the horizontal distance corresponding to the induction signal obtained when the dial indicator probe 4 is just located at the vertex of the calibration hemisphere 3 as the preset threshold value (represented by the symbol P). At this time, the distance between the fiber optic sensor and the rod body of the dial indicator is a constant value L. That is, the distance value L between the fiber optic sensor and the rod body of the dial indicator in this state is set as the preset threshold value.

[0091] (1) When the fiber optic amplifier is installed on the right side of the calibration hemisphere 3, if the horizontal distance corresponding to the obtained induction signal is greater than the preset threshold, it indicates that the dial indicator rod body is on the left side of the vertex of the calibration hemisphere 3; if the horizontal distance corresponding to the obtained induction signal is less than the preset threshold, it indicates that the dial indicator rod body is on the right side of the vertex of the calibration hemisphere 3;

[0092] More specifically,

[0093] Taking Figure 11 part (a) as an example, when the maximum height difference -h1 of the dial indicator reading occurs during the first crossing of the calibration hemisphere 3, the induction light ray ① emitted by the fiber optic sensor just acts on the dial indicator rod body. At this time, the fiber optic sensor senses signal A and feeds it back to the controller through the fiber optic amplifier. The horizontal distance corresponding to this signal A is represented by P1; when the maximum height difference -h2 of the dial indicator reading occurs during the second crossing of the calibration hemisphere 3, the induction light ray ② emitted by the fiber optic sensor just acts on the dial indicator rod body. At this time, the fiber optic sensor senses signal B and feeds it back to the controller through the fiber optic amplifier. The data corresponding to this signal B is represented by P2; since the distance L1 between the fiber optic sensor and the dial indicator rod body at -h1 is greater than the distance L2 between the fiber optic sensor and the dial indicator rod body at -h2, and both L1 and L2 are greater than L, therefore, it can be considered that P1 > P2 > P, corresponding to the dial indicator rod body being on the left side of the vertex of the calibration hemisphere 3, and both the maximum height difference -h1 and the maximum height difference -h2 correspond to the same side (left side) of the vertex; similarly, taking Figure 11 part (b) as an example, it can be considered that P < P1 < P2, corresponding to the dial indicator rod body being on the left side of the vertex of the calibration hemisphere 3, and both the maximum height difference -h1 and the maximum height difference -h2 correspond to the same side (left side) of the vertex; in these two cases, the calculation model formula (Ⅲ) can be called in step S4;

[0094] Among them, P, P1, and P2 represent the readings of the computer / controller, L, L1, and L2 represent the horizontal distance values, P corresponds to L, P1 corresponds to L1, and P2 corresponds to L2;

[0095] Taking Figure 12Taking part (a) as an example, when the maximum height difference -h1 is shown on the dial indicator during the first crossing of the calibration hemisphere 3, the induction ray ① emitted by the fiber optic sensor just acts on the rod body of the dial indicator. At this time, the fiber optic sensor senses signal A and feeds it back to the controller through the fiber optic amplifier. The horizontal distance corresponding to this signal A is represented by P1. When the maximum height difference -h2 is shown on the dial indicator during the second crossing of the calibration hemisphere 3, the induction ray ② emitted by the fiber optic sensor just acts on the rod body of the dial indicator. At this time, the fiber optic sensor senses signal B and feeds it back to the controller through the fiber optic amplifier. The data corresponding to this signal B is represented by P2. Since the distance L1 between the fiber optic sensor and the rod body of the dial indicator at -h1 is greater than the distance L2 between the fiber optic sensor and the rod body of the dial indicator at -h2, and L1 is greater than L while L2 is less than L, therefore, it can be considered that P1 > P > P2. Corresponding to the maximum height difference -h1, the rod body of the dial indicator is located on the left side of the vertex of the calibration hemisphere 3, and corresponding to the maximum height difference -h2, the rod body of the dial indicator is located on the right side of the vertex of the calibration hemisphere 3, that is, both the maximum height difference -h1 and the maximum height difference -h2 correspond to different sides of the vertex; similarly, taking Figure 12 Taking part (b) as an example, it can be considered that P1 < P < P2. Corresponding to the maximum height difference -h1, the rod body of the dial indicator is located on the right side of the vertex of the calibration hemisphere 3, and corresponding to the maximum height difference -h2, the rod body of the dial indicator is located on the left side of the vertex of the calibration hemisphere 3, that is, both the maximum height difference -h1 and the maximum height difference -h2 correspond to different sides of the vertex. In these two cases, the calculation model formula (Ⅳ) can be called in step S4;

[0096] Similarly, in Figure 11 the state shown, the relative position of the rod body of the dial indicator can also be determined according to the obtained induction signal;

[0097] Or,

[0098] (2) Referring to the judgment principle in part (1) of this step, when the fiber optic amplifier is installed on the left side of the calibration hemisphere 3, if the horizontal distance corresponding to the obtained induction signal is greater than the preset threshold, it means that the rod body of the dial indicator is located on the right side of the vertex of the calibration hemisphere 3. If the horizontal distance corresponding to the obtained induction signal is less than the preset threshold, it means that the rod body of the dial indicator is located on the left side of the vertex of the calibration hemisphere 3;

[0099] S4. Call the corresponding calculation model according to the obtained readings and relative positions, and calculate and output the linear repeat positioning accuracy.

[0100] In the solution of this example, compared with Embodiment 1, the functions of the fiber optic sensor and the vision system are to facilitate the realization of linear repeat positioning accuracy measurement more quickly, accurately and simply. The linear repeat positioning accuracy measurement can be completed in less than ten minutes (excluding the time for writing the winding path program), greatly reducing the operation process of the operator. With the help of the fiber optic sensor, the relative position of the dial indicator rod body is determined, and with the help of the vision system, the maximum height difference h1 and the maximum height difference h2 are obtained. Then, the linear repeat positioning accuracy value is obtained by calling the calculation model through the control system, thus realizing the more rapid, accurate and simple linear repeat positioning and accuracy measurement, and the measurement error can reach the micron level.

[0101] In the present invention, the linear repeat positioning accuracy is measured by means of the calibration hemisphere and the dial indicator, which belongs to non-destructive measurement, and can effectively avoid the deficiencies of the existing manual scribing inspection method, such as large measurement error and low measurement efficiency, and can greatly improve the measurement accuracy of the linear repeat positioning accuracy; the calibration hemisphere used as the measurement reference has a size that can be flexibly changed according to the core mold size, and the measurement position can be flexibly set, expanding the application range of the present invention; it can accurately, quickly and simply realize the measurement of the linear repeat positioning accuracy, with a simple operation process, easy to implement, and ordinary operators can operate smoothly; it can be applied to measure the linear repeat positioning accuracy in processes such as fiber placement, fiber tape laying, and 3D printing.

Claims

1. A method for measuring the linear repetitive positioning accuracy of a fiber winding machine, characterized in that the steps Including: Step 1: Draw a winding trajectory according to the actual winding path; Step 2: Install a calibration hemisphere at the center line of a specified position on the winding trajectory; Step 3: Fix a micrometer with a radius of r at the wire outlet of the fiber winding machine, run the fiber winding machine to complete a single-layer winding, and obtain the maximum height difference -h1 of the micrometer reading during the first crossing of the calibration hemisphere; Step 4: Continue to run the fiber winding machine, wind again or continuously for multiple times, and obtain the maximum height difference -h2 of the micrometer reading during the Nth crossing of the calibration hemisphere; Step 5: Calculate the horizontal distance S between the center of the micrometer probe corresponding to the maximum height difference -h1 and the center of the micrometer probe corresponding to the maximum height difference -h2. This horizontal distance S is the linear repeat positioning accuracy; When the maximum height difference -h1 corresponds to the vertex and is inside or outside relative to the maximum height difference -h2, the linear repeat positioning accuracy D02 is calculated using Equation (Ⅰ); When the maximum height difference -h2 corresponds to the vertex and is inside or outside relative to the maximum height difference -h1, the linear repeat positioning accuracy A02 is calculated using Equation (Ⅱ); When the maximum height differences -h1 and -h2 both correspond to the same side of the vertex, the linear repeat positioning accuracy AD is calculated using Equation (Ⅲ); When the maximum height differences -h1 and -h2 both correspond to both sides / different sides (different sides) of the vertex, the linear repeat positioning accuracy AD' is calculated using Equation (Ⅳ); In the formula, R represents the radius of the calibration hemisphere, and r represents the radius of the micrometer probe head.

2. The method according to claim 1, characterized in that The specific content of Step 1 includes: First, set the winding path program, then fix a marker pen on the wire outlet of the winding carriage, and then run the winding path program to draw a winding trajectory on the surface of the mandrel using the marker pen.

3. The method according to claim 1, characterized in that The specific content of Step 2 includes: Select a suitable calibration hemisphere with a radius of R, fix the calibration hemisphere at a specified position on the winding trajectory, and ensure that the center of the calibration hemisphere coincides with the center line of the specified position on the winding trajectory.

4. The method according to claim 1, characterized in that The specific content of Step 3 includes: First, replace the marker pen with a micrometer, then adjust the position of the micrometer so that the micrometer probe head is located at the junction of the edge of the calibration hemisphere and the mandrel and contacts the surface of the mandrel, and then perform a zeroing operation on the micrometer; then run the fiber winding machine to complete a single-layer winding, and record the maximum height difference -h1 of the micrometer reading during the first crossing of the calibration hemisphere.

5. The method according to claim 4, characterized in that: In Step 4, wind continuously 3 - 5 times, and use the average value or the maximum value of the maximum height difference of the readings as the maximum height difference -h2.

6. The method according to claim 1, characterized in that: Fix the calibration hemisphere at the center line of a specified position on the winding trajectory by means of bonding or threaded connection.

7. The method according to claim 1, characterized in that: The radius of the calibration hemisphere is not greater than 10 mm.

8. The method according to claim 1, characterized in that It further includes a controller which is connected to the fiber amplifier and the vision system. The vision system is used to identify the reading of the micrometer. The fiber sensor adapted to the fiber amplifier is installed on the side of the calibration hemisphere. When the micrometer probe moves to the plane of the central cross-section of the calibration hemisphere perpendicular to the center line, the sensing light emitted by the fiber sensor just acts on the rod body of the micrometer. The controller includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps / functions are realized: S1. When the micrometer probe moves to the plane of the central cross-section of the calibration hemisphere perpendicular to the center line, the fiber sensor senses the rod body of the micrometer and feeds back the sensing signal to the controller through the fiber amplifier; S2. At the moment when the controller receives the sensing signal, it obtains the reading of the micrometer through the vision system; S3. Determine the relative position of the rod body of the micrometer according to the obtained sensing signal; S4. Call the corresponding calculation model according to the obtained reading and relative position, calculate and output the linear repeat positioning accuracy.

9. The method according to claim 8, characterized in that In step S3: Define the horizontal distance corresponding to the sensing signal obtained when the calibration hemisphere probe is at the vertex of the calibration hemisphere as the preset threshold; (1) When the fiber amplifier is installed on the right side of the calibration hemisphere, if the horizontal distance corresponding to the obtained sensing signal is greater than the preset threshold, it means that the rod body of the micrometer is on the left side of the vertex of the calibration hemisphere; if the horizontal distance corresponding to the obtained sensing signal is less than the preset threshold, it means that the rod body of the micrometer is on the right side of the vertex of the calibration hemisphere; Or, (2) When the fiber amplifier is installed on the left side of the calibration hemisphere, if the horizontal distance corresponding to the obtained sensing signal is greater than the preset threshold, it means that the rod body of the micrometer is on the right side of the vertex of the calibration hemisphere; if the horizontal distance corresponding to the obtained sensing signal is less than the preset threshold, it means that the rod body of the micrometer is on the left side of the vertex of the calibration hemisphere.

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