Method for Obtaining VAD Guide Bar Offset Trend, Deposition Method and Deposition Equipment

Abstract

The present application relates to a method for obtaining a VAD guide rod offset trend, a deposition method, and a deposition apparatus, comprising: driving a guide rod from a starting position toward an end position along the Z direction; measuring the offset of the guide rod in the X and Y directions at multiple set positions between the starting and end positions; and obtaining a mapping relationship between the guide rod's X-direction offset velocity and growth time, and a mapping relationship between the guide rod's Y-direction offset velocity and growth time based on the set positions, growth rate, X-direction offset, and Y-direction offset. This application addresses the problem in related art that methods can only detect the deviation range of the guide rod but cannot detect the changing trend of the guide rod offset.

Description

Technical Field

[0001] The present application relates to the technical field of optical fiber preform manufacturing, and in particular to a method for obtaining a VAD guide rod deviation trend, a deposition method, and a deposition device. Background Art

[0002] The VAD method is currently the mainstream core rod preparation process. The equipment used to prepare optical fiber preform soot primarily consists of a deposition chamber, a raw material control cabinet, a blowtorch, a lifting system, and an exhaust system. The guide rods in the lifting system are a key component of the entire deposition system, and their stability directly impacts the quality of the deposited soot. During deposition, as the guide rods are gradually lifted, minute variations in the guide rail surface can affect the position of the lower end of the guide rods, thereby impacting the quality of the preform soot.

[0003] The traditional detection method is laser beam measurement. During the lifting process of the guide rod, the laser beam at the lower end of the guide rod will produce some points on the bottom plate of the deposition chamber. Through continuous collection, these points will form a point beam and are all concentrated in a certain circle. The diameter of the circle is the deviation range of the guide rod during the lifting process.

[0004] The aforementioned laser beam measurement method can produce offset errors exceeding ±2mm. By continuously adjusting the verticality of the guide rods, the deviation can be controlled to approximately ±1mm, but this is time-consuming. Furthermore, the typical deviation requirement for VAD processes is ±0.5mm, which in most cases does not meet process requirements.

[0005] In addition, this method can only detect the deviation range of the guide rod, but cannot detect the changing trend of the guide rod offset.

[0006] Therefore, the laser beam measurement method cannot provide good guidance for the VAD deposition process, and the need for the development of new technologies is urgent. Summary of the Invention

[0007] The embodiments of the present application provide a method for obtaining the VAD guide rod offset trend, a deposition method, and a deposition device to solve the problem that the methods in the related art can only detect the deviation range of the guide rod but cannot detect the changing trend of the guide rod offset.

[0008] In a first aspect, a method for obtaining a VAD guide rod deviation trend is provided, comprising:

[0009] Drive the guide rod from the starting position to the end position along the Z direction;

[0010] At multiple set positions between the starting position and the end position, the offset of the guide rod in the X direction and the Y direction is measured;

[0011] Based on the set position, growth rate, X-direction offset and Y-direction offset, a mapping relationship between the X-direction offset speed and the growth time of the guide rod and a mapping relationship between the Y-direction offset speed and the growth time are obtained.

[0012] In some embodiments, based on the set position, the offset in the X direction, and the offset in the Y direction, obtaining a mapping relationship between the offset speed in the X direction and the growth time of the guide rod and a mapping relationship between the offset speed in the Y direction and the growth time includes the following steps:

[0013] Perform curve fitting on the set position and the offset in the X direction to obtain a mapping relationship between the offset in the X direction and the position of the guide rod in the Z direction;

[0014] Perform curve fitting on the set position and the offset in the Y direction to obtain a mapping relationship between the offset in the Y direction and the position of the guide rod in the Z direction;

[0015] Based on the position of the guide rod in the Z direction, the growth rate, the growth time, and the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction, a mapping relationship between the X-direction offset speed and the growth time is obtained;

[0016] Based on the Z-direction position, growth rate, growth time, and the mapping relationship between the Y-direction offset and the Z-direction position of the guide rod, the mapping relationship between the Y-direction offset speed and the growth time is obtained.

[0017] In some embodiments, based on the mapping relationship between the position of the guide rod in the Z direction, the growth rate, the growth time, and the X-direction offset and the position of the guide rod in the Z direction, a mapping relationship between the X-direction offset speed and the growth time is obtained, specifically including:

[0018] Substituting the position of the guide rod in the Z direction as the product of the growth rate and the growth time into the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction, a mapping relationship between the X-direction offset and the growth time is obtained;

[0019] The mapping relationship between the X-direction offset and the growth time is derived once to obtain the mapping relationship between the X-direction offset speed and the growth time;

[0020] In some embodiments, based on the mapping relationship between the position of the guide rod in the Z direction, the growth rate, the growth time, and the Y-direction offset and the position of the guide rod in the Z direction, a mapping relationship between the Y-direction offset speed and the growth time is obtained, specifically including:

[0021] Substituting the position of the guide rod in the Z direction as the product of the growth rate and the growth time into the mapping relationship between the Y direction offset and the position of the guide rod in the Z direction, the mapping relationship between the Y direction offset and the growth time is obtained;

[0022] The mapping relationship between the Y-direction offset and the growth time is derived once to obtain the mapping relationship between the Y-direction offset speed and the growth time.

[0023] In some embodiments, the target rod is mounted on the guide rod;

[0024] Drive the guide rod and the nozzle to move simultaneously;

[0025] Among them, the speed of the nozzle movement meets the following conditions:

[0026] The movement speed of the nozzle in the X direction is equal to the X direction offset speed of the guide rod calculated from the mapping relationship between the X direction offset speed of the guide rod and the growth time;

[0027] The moving speed of the nozzle in the Y direction is equal to the Y direction offset speed of the guide rod calculated from the mapping relationship between the Y direction offset speed of the guide rod and the growth time.

[0028] In some embodiments, driving the nozzle to move specifically includes:

[0029] Based on the mapping relationship between the X-direction servo motor speed of the printhead and the growth time, the X-direction servo motor is driven to rotate so that the printhead moves in the X-direction;

[0030] Based on the mapping relationship between the Y-direction servo motor speed of the print head and the growth time, the Y-direction servo motor is driven to rotate so that the print head moves in the Y direction;

[0031] The mapping relationship between the X-direction servo motor speed of the printhead and the growth time is obtained based on the mapping relationship between the X-direction servo motor reduction ratio of the printhead, the X-direction lead screw, and the X-direction offset speed of the guide rod and the growth time.

[0032] Based on the mapping relationship between the Y-direction servo motor reduction ratio of the printhead, the Y-direction lead screw, and the Y-direction offset speed of the guide rod and the growth time, the mapping relationship between the Y-direction servo motor speed of the printhead and the growth time is obtained.

[0033] In a second aspect, a method for depositing an optical fiber preform is provided, comprising the following steps:

[0034] Install the target rod on the guide rod;

[0035] Drive the guide rod and the nozzle to move simultaneously;

[0036] The speed of the nozzle movement is obtained by the following method:

[0037] Based on the mapping relationship between the X-direction offset speed of the guide rod and the growth time, the mapping relationship between the X-direction offset of the guide rod and the growth time is inversely calculated;

[0038] Based on the mapping relationship between the Y-direction offset speed of the guide rod and the growth time, the mapping relationship between the Y-direction offset of the guide rod and the growth time is inversely calculated;

[0039] Based on the mapping relationship between the preform rod soot body length, growth rate, the number of time intervals in which the total deposition time is evenly divided, the X-direction servo motor reduction ratio of the nozzle, the X-direction lead screw, and the X-direction offset of the guide rod with respect to the growth time, the X-direction servo motor speed of the nozzle in each time interval is obtained;

[0040] Based on the mapping relationship between the preform rod loose body length, growth rate, the number of time intervals divided into the total deposition time, the Y-direction servo motor reduction ratio of the nozzle, the Y-direction screw lead, and the Y-direction offset of the guide rod with respect to the growth time, the Y-direction servo motor speed of the nozzle in each time interval is obtained.

[0041] In some embodiments, based on the mapping relationship between the preform soot length, the growth rate, the number of time intervals into which the total deposition time is divided, the reduction ratio of the X-direction servo motor of the nozzle, the X-direction lead of the lead screw, and the X-direction offset of the guide rod and the growth time, the X-direction servo motor speed of the nozzle in each time interval is obtained, specifically including:

[0042] The duration of each time interval is obtained based on the length of the preform soot body, the growth rate, and the number of time intervals evenly divided by the total deposition time;

[0043] Based on the mapping relationship between each time interval, the X-direction offset of the guide rod and the growth time, the X-direction offset of the nozzle in each time interval is obtained;

[0044] Based on the X-direction offset of the printhead, the duration of the corresponding time interval, the reduction ratio of the X-direction servo motor of the printhead, and the X-direction lead of the screw, the X-direction servo motor speed of the printhead in each time interval is obtained;

[0045] In some embodiments, based on the mapping relationship between the preform soot length, the growth rate, the number of time intervals into which the total deposition time is divided, the Y-direction servo motor reduction ratio of the nozzle, the Y-direction lead of the lead screw, and the Y-direction offset of the guide rod and the growth time, the Y-direction servo motor speed of the nozzle in each time interval is obtained, specifically including:

[0046] The duration of each time interval is obtained based on the length of the preform soot body, the growth rate, and the number of time intervals evenly divided by the total deposition time;

[0047] Based on the mapping relationship between each time interval, the Y-direction offset of the guide rod and the growth time, the Y-direction offset of the nozzle in each time interval is obtained;

[0048] Based on the Y-direction offset of the printhead, the duration of the corresponding time interval, the Y-direction servo motor reduction ratio of the printhead, and the Y-direction lead of the screw, the Y-direction servo motor speed of the printhead in each time interval is obtained.

[0049] In a third aspect, a deposition apparatus for an optical fiber preform is provided, comprising:

[0050] A deposition device includes a guide rod movable in the Z direction, wherein the bottom end of the guide rod is provided with a mounting port adapted to the target rod;

[0051] A spraying system including a spray head, an X-direction servo motor for driving the spray head to move in the X direction, and a Y-direction servo motor for driving the spray head to move in the Y direction;

[0052] The control system stores a mapping relationship between an X-direction offset speed of the guide rod and a growth time and a mapping relationship between an X-direction offset speed and a growth time. The control system is used to calculate the movement speed of the nozzle in the X direction and the movement speed in the Y direction based on the mapping relationship between the X-direction offset speed and the growth time, and drive the nozzle to move in the X direction and the Y direction through the X-direction servo motor and the Y-direction servo motor.

[0053] The beneficial effects of the technical solution provided by this application include:

[0054] Embodiments of the present application provide a method for obtaining a VAD guide rod offset trend, a deposition method, and a deposition apparatus. Based on a determined growth rate, specific values of each set position, and the offset in the X direction and the offset in the Y direction at each set position, curve fitting can be performed to obtain a mapping relationship between the guide rod's X-direction offset velocity and the growth time, and a mapping relationship between the guide rod's Y-direction offset velocity and the growth time.

[0055] The mapping relationship between the above-mentioned offset speed and the growth time can reflect the offset variation trend of the guide rod in the X and Y directions during the entire deposition process, rather than the deviation range during the guide rod lifting process.

[0056] By using this offset variation as a driving force, the VAD deposition process can be well guided to reduce the impact of the guide rod offset on the quality of the preform loose body, thereby improving product quality.

[0057] Specifically, based on the condition that the position from the nozzle to the deposition point during the deposition process is "constant", the mapping relationship between the offset speed and the growth time can be used to guide the movement direction and amount of the nozzle, so as to make the position from the nozzle to the deposition point "constant" as much as possible, thereby improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0059] Figure 1 A schematic diagram of a deposition apparatus provided in an embodiment of the present application;

[0060] Figure 2 A flow chart of a method for obtaining a VAD guide rod deviation trend provided in an embodiment of the present application;

[0061] Figure 3 Schematic diagram of the deposition equipment for optical fiber preform provided in an embodiment of the present application.

[0062] In the figure: 1. Tower; 2. Guide rail slider; 3. Motion platform; 4. Guide rod; 5. Detection tool rod; 6. Deposition chamber; 7. X-direction offset detector; 8. Y-direction offset detector; 9. Detector fixing rod; 10. Target rod; 11. Core layer nozzle; 12. Cladding nozzle; 13. Control system. DETAILED DESCRIPTION

[0063] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0064] See also Figure 1 As shown, in order to obtain the VAD guide rod offset trend, a deposition device is provided, which includes a tower 1, a guide rail slider 2, a moving platform 3, a guide rod 4, a detection tool rod 5, a deposition chamber 6, an X-direction offset detector 7, a Y-direction offset detector 8, and a detector fixing rod 9.

[0065] The guide rail slider 2 is installed on the tower 1, the moving platform 3 is movably installed on the guide rail slider 2, the guide rod 4 is fixed on the moving platform 3, the detection tooling rod 5 is installed at the bottom end of the guide rod 4 and is located in the deposition chamber 6, the X-direction offset detector 7 and the Y-direction offset detector 8 are both installed on the detector fixing rod 9, and measure the offset of the detection tooling rod 5 in the X direction and the offset in the Y direction respectively, thereby obtaining the offset of the guide rod 4 in the X direction and the offset in the Y direction.

[0066] The X-direction offset detector 7 and the Y-direction offset detector 8 can adopt a dial indicator, the dial indicator head is installed on the detection fixture rod 5, and the dial indicator is installed on the detector fixing rod 9.

[0067] The Z direction is a vertical direction, and the X direction and the Y direction are perpendicular to each other and are both perpendicular to the Z direction.

[0068] Combine Figure 1 and Figure 2 As shown, the embodiment of the present application provides a method for obtaining a VAD guide rod deviation trend, which includes the following steps:

[0069] 101: Drive the guide rod from the starting position to the end position along the Z direction.

[0070] The starting position can be set as 0, and the end position can be determined according to the length of the preform loose body. For example, as an example, the end position can be set as 1800 mm.

[0071] The movement speed of the guide rod can be determined according to the actual deposition needs, for example, the movement speed can be controlled at 200-600 mm / min.

[0072] 102: measuring the offset of the guide rod in the X direction and the Y direction at multiple set positions between the starting position and the end position;

[0073] The number of setting positions can be determined according to actual needs. For example, a setting position is determined at every 20-40mm interval. As an example, a setting position is determined at a 30mm interval. The total movement distance is 1800mm, so there are 60 setting positions.

[0074] When the guide rod reaches a set position, the offset detector can detect the offset of the guide rod in the X direction and the Y direction.

[0075] The entire detection process can be recorded in a video format for data recording and organization.

[0076] 103: Based on the set position, growth rate, X-direction offset and Y-direction offset, obtain a mapping relationship between the X-direction offset speed and the growth time of the guide rod and a mapping relationship between the Y-direction offset speed and the growth time.

[0077] The growth rate is also the lifting speed of the guide rod, and the unit is mm / min. The value is generally 0.8-2 mm / min. In the actual deposition process, under a certain process, the growth rate is generally a constant value.

[0078] Based on the determined growth rate, the specific values of each set position, and the offset in the X direction and the offset in the Y direction at each set position, curve fitting can be performed to obtain the mapping relationship between the X-direction offset speed of the guide rod and the growth time, and the mapping relationship between the Y-direction offset speed and the growth time.

[0079] The mapping relationship between the above-mentioned offset speed and the growth time can reflect the offset variation trend of the guide rod in the X and Y directions during the entire deposition process, rather than the deviation range during the guide rod lifting process.

[0080] By using this offset variation as a driving force, the VAD deposition process can be well guided to reduce the impact of the guide rod offset on the quality of the preform loose body, thereby improving product quality.

[0081] Specifically, based on the condition that the position from the nozzle to the deposition point during the deposition process is "constant", the mapping relationship between the offset speed and the growth time can be used to guide the movement direction and amount of the nozzle, so as to make the position from the nozzle to the deposition point "constant" as much as possible, thereby improving product quality.

[0082] In step 103, based on the set position, the offset in the X direction, and the offset in the Y direction, a mapping relationship between the offset speed in the X direction and the growth time of the guide rod and a mapping relationship between the offset speed in the Y direction and the growth time are obtained, which specifically includes the following steps:

[0083] 201: performing curve fitting on the set position and the offset in the X direction to obtain a mapping relationship between the offset in the X direction and the position of the guide rod in the Z direction;

[0084] Curve fitting is performed on the set position and the offset in the Y direction to obtain a mapping relationship between the offset in the Y direction and the position of the guide rod in the Z direction.

[0085] In step 201, the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction is as follows:

[0086] D x (z) = a n z n +a n-1 z n-1 +...+a4z 4 +a3z 3 +a2z 2 +a1z+a0 (1)

[0087] In step 201, the mapping relationship between the Y-direction offset and the position of the guide rod in the Z direction is as follows:

[0088] D y (z) = b nz n +b n-1 z n-1 +...+b4z 4 +b3z 3 +b2z 2 +b1z+b0 (2)

[0089] Where z is the position of the guide rod in the Z direction, in mm.

[0090] a i , b i are the fitting coefficients of the corresponding terms of the polynomial, i = 0, 1, 2, 3, ..., n.

[0091] 202: Based on the position of the guide rod in the Z direction, the growth rate, the growth time, and the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction, obtain a mapping relationship between the X-direction offset speed and the growth time;

[0092] Based on the Z-direction position, growth rate, growth time, and the mapping relationship between the Y-direction offset and the Z-direction position of the guide rod, the mapping relationship between the Y-direction offset speed and the growth time is obtained.

[0093] In step 202, the mapping relationship between the X-direction offset speed and the growth time is as follows:

[0094] D′ x (t) = nc n t n-1 +(n-1)c n-1 t n-2 +...+4c4t 3 +3c3t 2 +2c2t+c1 (3)

[0095] In step 202, the mapping relationship between the Y-direction offset speed and the growth time is as follows:

[0096] D′ y (t) = nd n t n-1 +(n-1)d n-1 t n-2 +...+4d4t 3 +3d3t 2 +2d2t+d1 (4)

[0097] in,

[0098]

[0099] z=v z t;v zis the growth rate; t is the growth time, that is, the lifting time of the guide rod, in minutes.

[0100] In step 202, based on the position of the guide pin in the Z direction, the growth rate, the growth time, and the mapping relationship between the X-direction offset and the position of the guide pin in the Z direction, a mapping relationship between the X-direction offset speed and the growth time is obtained, which specifically includes the following steps:

[0101] 301: Substituting the position of the guide rod in the Z direction as the product of the growth rate and the growth time into the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction, to obtain a mapping relationship between the X-direction offset and the growth time.

[0102] Specifically, z=v z Substituting t into the above formula (1), we can obtain the mapping relationship between the X-direction offset and the growth time, namely:

[0103] D x (t) = c n t n +c n-1 t n-1 +...+c4t 4 +c3t 3 +c2t 2 +c1t+c0 (5)

[0104] in,

[0105] 302: Derivative the mapping relationship between the X-direction offset and the growth time to obtain the mapping relationship between the X-direction offset speed and the growth time, which is the above formula (3).

[0106] In step 202, based on the position of the guide rod in the Z direction, the growth rate, the growth time, and the mapping relationship between the Y direction offset and the position of the guide rod in the Z direction, a mapping relationship between the Y direction offset speed and the growth time is obtained, which specifically includes the following steps:

[0107] 401: Substitute the position of the guide rod in the Z direction as the product of the growth rate and the growth time into the mapping relationship between the Y direction offset and the position of the guide rod in the Z direction to obtain the mapping relationship between the Y direction offset and the growth time.

[0108] Specifically, z=v z Substituting t into the above formula (2), we can obtain the mapping relationship between the Y-direction offset and the growth time, namely:

[0109] D y (t) = d n t n +d n-1 tn-1 +...+d4t 4 +d3t 3 +d2t 2 +d1t+d0 (6)

[0110] in,

[0111] 402: Derivative the mapping relationship between the Y-direction offset and the growth time to obtain the mapping relationship between the Y-direction offset speed and the growth time, which is the above formula (4).

[0112] The present invention also provides a method for depositing an optical fiber preform, which comprises the following steps:

[0113] 501: Install the target rod on the guide rod.

[0114] 502: Driving the guide rod and the nozzle to move simultaneously; wherein the speed of the nozzle movement satisfies the following conditions:

[0115] The movement speed of the nozzle in the X direction is equal to the X direction offset speed of the guide rod calculated from the mapping relationship between the X direction offset speed of the guide rod and the growth time;

[0116] The moving speed of the nozzle in the Y direction is equal to the Y direction offset speed of the guide rod calculated from the mapping relationship between the Y direction offset speed of the guide rod and the growth time.

[0117] By keeping the movement speed of the nozzle consistent with the offset speed of the guide rod at all times, the position from the nozzle to the deposition point can be guaranteed to be "constant" during the deposition process. This can well guide the VAD deposition process to reduce the impact of the guide rod offset on the quality of the preform rod loose body, thereby improving product quality.

[0118] It should be noted that in step 502 , the mapping relationship between the X-direction offset speed of the guide rod and the growth time and the mapping relationship between the Y-direction offset speed and the growth time can be obtained using the method for obtaining the VAD guide rod offset trend provided in the above embodiment.

[0119] It should be noted that, since the offset of the guide rods is different in different deposition devices, the deposition device used to obtain the mapping relationship between the X-direction offset speed of the guide rod and the growth time and the mapping relationship between the Y-direction offset speed and the growth time in step 502 should theoretically be the same deposition device as the deposition device used to deposit the preform rod loose body in steps 501 and 502.

[0120] Usually, the nozzle is driven by a servo motor, and the movement speed of the nozzle can ultimately be reflected by the rotation speed of the servo motor. Therefore, further, the movement of the nozzle can be converted into controlling the rotation speed of the servo motor, and then only the rotation speed of the servo motor needs to be controlled.

[0121] Specifically, in step 502, driving the nozzle to move includes the following steps:

[0122] 601: Based on a mapping relationship between the X-direction servo motor speed of the printhead and the growth time, drive the X-direction servo motor to rotate so as to move the printhead in the X-direction; wherein, based on a mapping relationship between the X-direction servo motor speed of the printhead, the X-direction lead screw, and the X-direction offset speed of the guide rod and the growth time, the mapping relationship between the X-direction servo motor speed of the printhead and the growth time is obtained.

[0123] 602: Based on the mapping relationship between the Y-direction servo motor speed of the nozzle and the growth time, the Y-direction servo motor is driven to rotate so that the nozzle moves in the Y-direction; wherein, based on the mapping relationship between the Y-direction servo motor reduction ratio of the nozzle, the Y-direction lead screw, and the Y-direction offset speed of the guide rod and the growth time, the mapping relationship between the Y-direction servo motor speed of the nozzle and the growth time is obtained.

[0124] Because the moving speed of the nozzle is always consistent with the offset speed of the guide rod.

[0125] Therefore, the mapping relationship between the X-direction offset speed of the guide rod and the growth time, and the mapping relationship between the X-direction servo motor reduction ratio of the printhead, the X-direction screw lead, and the X-direction servo motor speed and the growth time are as follows:

[0126] D′ x (t) = n x (t)p x / r x (7)

[0127] Therefore, the mapping relationship between the Y-direction offset speed of the guide rod and the growth time, and the mapping relationship between the Y-direction servo motor reduction ratio of the printhead, the Y-direction screw lead, and the Y-direction servo motor speed and the growth time are as follows:

[0128] D′ y (t) = n y (t)p y / r y (8)

[0129] Among them, n x (t), n y(t) are the mapping relationship between the X-direction servo motor speed and the growth time, and the Y-direction servo motor speed and the growth time, in r / min;

[0130] p x , p y They are the X-direction lead of the screw and the Y-direction lead of the screw, in mm:

[0131] r x , r y They are the reduction ratio of the servo motor in the X direction and the reduction ratio of the servo motor in the Y direction respectively.

[0132] Combining formulas (3) and (4), we can obtain the following mapping relationship between the X-direction servo motor speed and the growth time:

[0133] n x (t) = e n t n-1 +e n-1 t n-2 +...+e4t 3 +e3t 2 +e2t+e1 (9)

[0134] The mapping relationship between the Y-direction servo motor speed and the growth time is:

[0135] n y (t) = f n t n-1 +f n-1 t n-2 +...+f4t 3 +f3t 2 +f2t+f1 (10)

[0136] in,

[0137]

[0138] The mapping between the printhead's servo motor speed and growth time is identical to the mapping between the offset and growth time. When the polynomial fitted in the mapping is first degree, the servo motor uses constant speed control. When the polynomial is second degree, the servo motor speed follows a linear equation, which is more complex. When the polynomial is third degree or greater, the servo motor speed changes very complexly.

[0139] When the degree of the fitting curve polynomial is large, it will make it difficult to adjust the servo motor speed in a short time, or even impossible to adjust it in time. At this time, optimization processing can be performed.

[0140] Therefore, an embodiment of the present application further provides a method for depositing an optimized optical fiber preform, which comprises the following steps:

[0141] 701: Install the target rod on the guide rod.

[0142] 702: driving the guide rod and the nozzle to move simultaneously;

[0143] The speed of the nozzle movement is obtained by the following method:

[0144] 801: Based on the mapping relationship between the X-direction offset speed of the guide rod and the growth time, the mapping relationship between the X-direction offset of the guide rod and the growth time is inversely calculated, that is, based on the above formula (3), formula (5) is inversely calculated;

[0145] Based on the mapping relationship between the Y-direction offset speed of the guide rod and the growth time, the mapping relationship between the Y-direction offset of the guide rod and the growth time is inversely calculated, that is, based on the above formula (4), formula (6) is inversely calculated.

[0146] 802: Based on the mapping relationship between the preform soot length, the growth rate, the number of time intervals divided into the total deposition time, the X-direction servo motor reduction ratio of the nozzle, the X-direction lead screw, and the X-direction offset of the guide rod and the growth time, the X-direction servo motor speed of the nozzle in each time interval is obtained;

[0147] Based on the mapping relationship between the preform rod loose body length, growth rate, the number of time intervals divided into the total deposition time, the Y-direction servo motor reduction ratio of the nozzle, the Y-direction screw lead, and the Y-direction offset of the guide rod with respect to the growth time, the Y-direction servo motor speed of the nozzle in each time interval is obtained.

[0148] In this embodiment, the total deposition time is divided into multiple time intervals. Within each time interval, the servo motor is operated at a constant speed. This allows the servo motor to output at a constant speed within a small time interval to maintain approximate position control of the printhead. This allows the position of the printhead and the deposition point to vary within a very small range. Even if there is a deviation, the deviation can be controlled within ±0.5mm, significantly improving product quality.

[0149] In step 802, based on the mapping relationship between the preform soot length, the growth rate, the number of time intervals divided into the total deposition time, the reduction ratio of the X-direction servo motor of the nozzle, the X-direction lead of the lead screw, and the X-direction offset of the guide rod and the growth time, the X-direction servo motor speed of the nozzle in each time interval is obtained, which specifically includes the following steps:

[0150] 901: Based on the length of the preform rod soot body, the growth rate, and the number of time intervals evenly divided into the total deposition time, the length of each time interval is obtained.

[0151] Specifically, the total deposition time T:

[0152] Wherein, L is the length of the preform loose body, which is known in advance.

[0153] The duration of the time interval ΔT:

[0154] Where N is the number of time intervals divided into the total deposition time.

[0155] 902: Based on the mapping relationship between each time interval, the X-direction offset of the guide rod and the growth time, obtain the X-direction offset of the nozzle in each time interval;

[0156] In the jth time interval, the X-direction offset of the nozzle is as follows:

[0157] S xj =D x (jΔT)-D x [(j-1)ΔT], j=1,2,3,…,N

[0158] 903: Based on the X-direction offset of the printhead, the duration of the corresponding time interval, the reduction ratio of the X-direction servo motor of the printhead, and the X-direction lead of the screw, the X-direction servo motor speed of the printhead in each time interval is obtained;

[0159] The X-direction servo motor speed of the printhead is as follows:

[0160]

[0161] In step 802, based on the mapping relationship between the preform soot length, the growth rate, the number of time intervals divided into the total deposition time, the Y-direction servo motor reduction ratio of the nozzle, the Y-direction lead of the lead screw, and the Y-direction offset of the guide rod and the growth time, the Y-direction servo motor speed of the nozzle in each time interval is obtained, which specifically includes the following steps:

[0162] 1001: Based on the length of the preform rod soot body, the growth rate, and the number of time intervals evenly divided into the total deposition time, the length of each time interval is obtained.

[0163] Specifically, the total deposition time T:

[0164] Wherein, L is the length of the preform loose body, which is known in advance.

[0165] The duration of the time interval ΔT:

[0166] Where N is the number of time intervals divided into the total deposition time.

[0167] 1002: Based on the mapping relationship between each time interval, the Y-direction offset of the guide rod and the growth time, obtain the Y-direction offset of the nozzle in each time interval;

[0168] In the jth time interval, the Y-direction offset of the nozzle is as follows:

[0169] S yj =D y (jΔT)-D y [(j-1)ΔT],j=1,2,3,…,N

[0170] 1003: Based on the Y-direction offset of the printhead, the duration of the corresponding time interval, the Y-direction servo motor reduction ratio of the printhead, and the Y-direction lead of the lead screw, the Y-direction servo motor speed of the printhead in each time interval is obtained.

[0171] The Y-direction servo motor speed of the printhead is as follows:

[0172]

[0173] See also Figure 3 As shown, an embodiment of the present application further provides a deposition device for an optical fiber preform, which includes a deposition device, a spraying system, and a control system 13, wherein the deposition device includes a guide rod 4 movable in the Z direction, and a mounting port adapted for a target rod 10 is provided at the bottom end of the guide rod; the spraying system includes a nozzle, an X-direction servo motor for driving the nozzle to move in the X direction, and a Y-direction servo motor for driving the nozzle to move in the Y direction, the nozzle including a core nozzle 11 and a cladding nozzle 12; the control system 13 stores a mapping relationship between the X-direction offset speed of the guide rod and the growth time and a mapping relationship between the Y-direction offset speed and the growth time, and the control system 13 is used to calculate the movement speed of the nozzle in the X direction and the movement speed in the Y direction based on the mapping relationship between the X-direction offset speed and the growth time, and drive the nozzle to move in the X direction and the Y direction through the X-direction servo motor and the Y-direction servo motor.

[0174] It should be noted that the mapping relationship between the X-direction offset speed of the guide rod and the growth time and the mapping relationship between the Y-direction offset speed and the growth time can be obtained by using the method for obtaining the VAD guide rod offset trend provided in the above embodiment.

[0175] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply 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 a limitation on this application. 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 an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0176] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0177] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for obtaining a VAD guide rod deviation trend, characterized in that: It includes: Drive the guide rod from the starting position to the end position along the Z direction; At multiple set positions between the starting position and the end position, the offset of the guide rod in the X direction and the Y direction is measured; Based on the set position, growth rate, X-direction offset and Y-direction offset, a mapping relationship between the X-direction offset speed and the growth time of the guide rod and a mapping relationship between the Y-direction offset speed and the growth time are obtained.

2. The method for obtaining the VAD guide rod deviation trend according to claim 1, characterized in that: Based on the set position, the offset in the X direction, and the offset in the Y direction, a mapping relationship between the offset speed in the X direction and the growth time of the guide rod and a mapping relationship between the offset speed in the Y direction and the growth time are obtained, including the following steps: Perform curve fitting on the set position and the offset in the X direction to obtain a mapping relationship between the offset in the X direction and the position of the guide rod in the Z direction; Perform curve fitting on the set position and the offset in the Y direction to obtain a mapping relationship between the offset in the Y direction and the position of the guide rod in the Z direction; Based on the position of the guide rod in the Z direction, the growth rate, the growth time, and the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction, a mapping relationship between the X-direction offset speed and the growth time is obtained; Based on the Z-direction position, growth rate, growth time, and the mapping relationship between the Y-direction offset and the Z-direction position of the guide rod, the mapping relationship between the Y-direction offset speed and the growth time is obtained.

3. The method for obtaining the VAD guide rod deviation trend according to claim 2, characterized in that: Based on the mapping relationship between the position of the guide rod in the Z direction, the growth rate, the growth time, and the X-direction offset amount with respect to the position of the guide rod in the Z direction, the mapping relationship between the X-direction offset speed and the growth time is obtained, specifically including: Substituting the position of the guide rod in the Z direction as the product of the growth rate and the growth time into the mapping relationship between the X-direction offset and the position of the guide rod in the Z direction, a mapping relationship between the X-direction offset and the growth time is obtained; The mapping relationship between the X-direction offset and the growth time is derived once to obtain the mapping relationship between the X-direction offset speed and the growth time.

4. The method for obtaining the VAD guide rod deviation trend according to claim 2, wherein: Based on the mapping relationship between the position of the guide rod in the Z direction, the growth rate, the growth time, and the Y direction offset relative to the position of the guide rod in the Z direction, the mapping relationship between the Y direction offset speed and the growth time is obtained, specifically including: Substituting the position of the guide rod in the Z direction as the product of the growth rate and the growth time into the mapping relationship between the Y direction offset and the position of the guide rod in the Z direction, the mapping relationship between the Y direction offset and the growth time is obtained; The mapping relationship between the Y-direction offset and the growth time is derived once to obtain the mapping relationship between the Y-direction offset speed and the growth time.

5. A method for depositing an optical fiber preform, characterized in that: It includes the following steps: Install the target rod on the guide rod; Drive the guide rod and the nozzle to move simultaneously; Among them, the speed of the nozzle movement meets the following conditions: The movement speed of the nozzle in the X direction is equal to the X direction offset speed of the guide rod calculated from the mapping relationship between the X direction offset speed of the guide rod and the growth time; The moving speed of the nozzle in the Y direction is equal to the Y direction offset speed of the guide rod calculated from the mapping relationship between the Y direction offset speed of the guide rod and the growth time; Driving the nozzle to move, including: Based on the mapping relationship between the X-direction servo motor speed of the print head and the growth time, the X-direction servo motor is driven to rotate so that the print head moves in the X-direction; Based on the mapping relationship between the Y-direction servo motor speed of the print head and the growth time, the Y-direction servo motor is driven to rotate so that the print head moves in the Y direction; The mapping relationship between the X-direction servo motor speed of the printhead and the growth time is obtained based on the mapping relationship between the X-direction servo motor reduction ratio of the printhead, the X-direction lead screw, and the X-direction offset speed of the guide rod and the growth time. Based on the mapping relationship between the Y-direction servo motor reduction ratio of the printhead, the Y-direction lead screw, and the Y-direction offset speed of the guide rod and the growth time, the mapping relationship between the Y-direction servo motor speed of the printhead and the growth time is obtained.

6. A method for depositing an optical fiber preform, characterized in that: It includes the following steps: Install the target rod on the guide rod; Drive the guide rod and the nozzle to move simultaneously; The speed of the nozzle movement is obtained by the following method: Based on the mapping relationship between the X-direction offset speed of the guide rod and the growth time, the mapping relationship between the X-direction offset of the guide rod and the growth time is inversely calculated; Based on the mapping relationship between the Y-direction offset speed of the guide rod and the growth time, the mapping relationship between the Y-direction offset of the guide rod and the growth time is inversely calculated; Based on the mapping relationship between the preform rod soot body length, growth rate, the number of time intervals in which the total deposition time is evenly divided, the X-direction servo motor reduction ratio of the nozzle, the X-direction lead screw, and the X-direction offset of the guide rod with respect to the growth time, the X-direction servo motor speed of the nozzle in each time interval is obtained; Based on the mapping relationship between the preform rod loose body length, growth rate, the number of time intervals divided into the total deposition time, the Y-direction servo motor reduction ratio of the nozzle, the Y-direction screw lead, and the Y-direction offset of the guide rod with respect to the growth time, the Y-direction servo motor speed of the nozzle in each time interval is obtained.

7. The optical fiber preform deposition method according to claim 6, wherein: Based on the mapping relationship between the preform rod soot body length, growth rate, the number of time intervals in which the total deposition time is divided, the X-direction servo motor reduction ratio of the nozzle, the X-direction lead screw, and the X-direction offset of the guide rod with respect to the growth time, the X-direction servo motor speed of the nozzle in each time interval is obtained, specifically including: The duration of each time interval is obtained based on the length of the preform soot body, the growth rate, and the number of time intervals evenly divided by the total deposition time; Based on the mapping relationship between each time interval, the X-direction offset of the guide rod and the growth time, the X-direction offset of the nozzle in each time interval is obtained; Based on the X-direction offset of the printhead, the duration of the corresponding time interval, the reduction ratio of the X-direction servo motor of the printhead, and the X-direction lead of the screw, the X-direction servo motor speed of the printhead in each time interval is obtained.

8. The optical fiber preform deposition method according to claim 6, wherein: Based on the mapping relationship between the preform rod soot body length, growth rate, the number of time intervals in which the total deposition time is divided, the Y-direction servo motor reduction ratio of the nozzle, the Y-direction lead screw, and the Y-direction offset of the guide rod with respect to the growth time, the Y-direction servo motor speed of the nozzle in each time interval is obtained, specifically including: The duration of each time interval is obtained based on the length of the preform soot body, the growth rate, and the number of time intervals evenly divided by the total deposition time; Based on the mapping relationship between each time interval, the Y-direction offset of the guide rod and the growth time, the Y-direction offset of the nozzle in each time interval is obtained; Based on the Y-direction offset of the printhead, the duration of the corresponding time interval, the Y-direction servo motor reduction ratio of the printhead, and the Y-direction lead of the screw, the Y-direction servo motor speed of the printhead in each time interval is obtained.

9. An optical fiber preform deposition device, characterized in that: It includes: A deposition device includes a guide rod movable in the Z direction, wherein the bottom end of the guide rod is provided with a mounting port adapted to the target rod; A spraying system including a spray head, an X-direction servo motor for driving the spray head to move in the X direction, and a Y-direction servo motor for driving the spray head to move in the Y direction; The control system stores a mapping relationship between an X-direction offset speed of the guide rod and a growth time and a mapping relationship between an X-direction offset speed and a growth time. The control system is used to calculate the movement speed of the nozzle in the X direction and the movement speed in the Y direction based on the mapping relationship between the X-direction offset speed and the growth time, and drive the nozzle to move in the X direction and the Y direction through the X-direction servo motor and the Y-direction servo motor.

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