A scanning bed height calibration method
Patent Information
- Application Number
- CN202611061057.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-16
- Publication Date
- 2026-10-30
AI Technical Summary
[0003]然而，现有标定方法中，在安装编码器时，需要反复调整编码器使编码器的位置与水平方向对准，对准过程需要反复拆装编码器，并且无法直接测量编码器的输出角度与水平方向的角度
本申请利用旋转编码器与四轴连杆升降结构中指定轴可动连接的结构特征，获取待标定扫描床在第一极限位置、第二极限位置各自的高度值 、水平位置值，并记录所述旋转编码器在所述第二极限位置输出的角度值，以计算确定所述待标定扫描床的主动摆杆的长度、及角度标定值，能够自动计算出主动摆杆的长度（包含了机械加工误差的补偿），利用所计算的计算角度标定值直接调整旋转编码器相对于第一水平定杆的位置，有效避免了旋转编码器的多次安装、拆卸，解决了旋转编辑器安装时对准水平线找零困难的问题，进而提高了待标定扫描床的标定过程；根据所计算的角度标定值、所述主动摆杆的长度所确定的关联关系，能够计算得到所述待标定扫描床在当前时间的高度，能够有效使原本需要反复安装和反复测试才能完成的扫描床标定过程简化为一次安装和两次测量即可完成待标定扫描床的标定过程，由此，大大缩减了调试所需的人工成本，同时还有效增加了待标定扫描床的高度准确性。
Smart Images
Figure CN122997732A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of medical device technology, specifically to a method for calibrating the height of a scanning bed. Background Technology
[0002] The scanning bed is one of the core components of a CT scanner, and its structural design directly affects patient comfort, scanning accuracy, and system stability. Currently, the main structural types are scissor-type and parallelogram-type.
[0003] However, existing calibration methods require repeated adjustments to the encoder during installation to align its position with the horizontal direction. This alignment process necessitates repeated disassembly and reassembly of the encoder, and it is impossible to directly measure the encoder's output angle relative to the horizontal direction. Due to factors such as machining and installation errors, the entire process of aligning the encoder horizontally for height calibration of the scanning bed is particularly cumbersome, and the results obtained are of low accuracy.
[0004] Therefore, it is necessary to provide a scanning bed height calibration method to solve the above-mentioned technical problems. Summary of the Invention
[0005] The purpose of this application is to provide a scanning bed height calibration method that can solve at least one of the aforementioned technical problems. The specific solution is as follows: According to a specific embodiment of this application, this application provides a scanning bed height calibration method, comprising: adjusting the scanning bed to be calibrated to a first extreme position, obtaining a first height value and a first horizontal position value of the scanning bed to be calibrated, and recording a first angle value output by a rotary encoder at the first extreme position; adjusting the scanning bed to be calibrated to a second extreme position, obtaining a second height value and a second horizontal position value of the scanning bed to be calibrated, and recording a second angle value output by the rotary encoder at the second extreme position; determining the length of the active swing arm and the angle calibration value of the scanning bed to be calibrated based on the first height value, the first horizontal position value, the first angle value, the second height value, the second horizontal position value, and the second angle value; calculating the height of the scanning bed to be calibrated at the current time according to the correlation determined by the calculated angle calibration value and the length of the active swing arm, wherein the scanning bed to be calibrated includes a four-axis linkage lifting structure and a rotary encoder connected to a designated shaft in the four-axis linkage lifting structure.
[0006] Compared with the prior art, the above-described solutions of this application have at least the following beneficial effects: This application utilizes the structural feature of a rotary encoder and a four-axis linkage lifting structure with a movable connection to a specified shaft to obtain the height and horizontal position values of the scanning bed to be calibrated at the first and second extreme positions, and records the angle value output by the rotary encoder at the second extreme position. This allows for the calculation and determination of the length and angle calibration value of the active swing arm of the scanning bed to be calibrated. The length of the active swing arm (including compensation for machining errors) can be automatically calculated. The calculated angle calibration value is used to directly adjust the position of the rotary encoder relative to the first horizontal fixed rod, effectively avoiding multiple installations and disassemblies of the rotary encoder and solving the problem of difficulty in aligning with the horizontal line during rotary editor installation, thus improving the calibration process of the scanning bed to be calibrated. Based on the correlation determined by the calculated angle calibration value and the length of the active swing arm, the height of the scanning bed to be calibrated at the current time can be calculated. This effectively simplifies the scanning bed calibration process, which originally required repeated installations and tests, to a single installation and two measurements, significantly reducing the labor costs required for debugging and effectively increasing the height accuracy of the scanning bed to be calibrated. Attached Figure Description
[0007] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 This is a schematic flowchart of the scanning bed height calibration method according to an embodiment of this application; Figure 2 This is a schematic diagram illustrating an application example of the scanning bed height calibration method according to an embodiment of this application; Figure 3 This is a schematic diagram illustrating the principle of a scanning bed height calibration method according to an embodiment of this application.
[0008] Figure label: 10: Scanning bed to be calibrated; 20: Four-axis linkage lifting structure; 30: Rotary encoder; 40: Base; AD: Active swing arm; BC: Driven swing arm; AB: First horizontal fixed rod; CD: Second horizontal fixed rod; A: Designated axis; B: Base axis; D: First bed axis; C: Second bed axis. Detailed Implementation
[0009] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0010] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.
[0011] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0012] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of this application for description, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of this application, and similarly, second may also be referred to as first.
[0013] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.
[0014] The purpose of this application is to provide a method for calibrating the height of a scanning bed. This method involves obtaining a first height value and a first horizontal position value of the scanning bed to be calibrated at a first extreme position, and recording a first angle value output by a rotary encoder at the first extreme position; obtaining a second height value and a second horizontal position value of the scanning bed to be calibrated at a second extreme position, and recording a second angle value output by the rotary encoder at the second extreme position; determining the length of the active swing arm and the angle calibration value of the scanning bed to be calibrated based on the first height value, the first horizontal position value, the first angle value, the second height value, the second horizontal position value, and the second angle value; and calculating the height of the scanning bed to be calibrated at the current time based on the correlation determined by the calculated angle calibration value and the length of the active swing arm. The scanning bed to be calibrated includes a four-axis linkage lifting structure and a rotary encoder connected to a designated axis in the four-axis linkage lifting structure.
[0015] It should be noted that this application is particularly applicable to calibrating scanning beds with a parallelogram structure.
[0016] The following is in conjunction with the appendix Figure 1 , Figure 2 , Figure 3 Detailed description of optional embodiments of the method of this application.
[0017] like Figure 1 As shown, this application provides a scanning bed height calibration method, which includes the following steps.
[0018] First, in step S101, the scanning bed to be calibrated is adjusted to the first limit position, the first height value and the first horizontal position value of the scanning bed to be calibrated are obtained, and the first angle value output by the rotary encoder at the first limit position is recorded. The scanning bed to be calibrated includes a four-axis linkage lifting structure and a rotary encoder connected to a specified shaft in the four-axis linkage lifting structure.
[0019] exist Figure 2 In the application example diagram, the scanning bed 10 to be calibrated includes a four-axis linkage lifting structure 20 and a rotary encoder 30 connected to a specified axis A in the four-axis linkage lifting structure 20.
[0020] In this example, a four-axis linkage lifting structure 20 is used to drive the lifting process of the scanning bed 10 to be calibrated. A rotary encoder 30 is used to measure the angle formed by the active swing arm AD of the four-axis linkage lifting structure 20 and the first horizontal fixed rod AB.
[0021] It should be noted that in this application, the horizontal direction is defined as the left-right direction of the attached drawing paper, and the vertical direction is defined as the up-down direction of the attached drawing paper, that is, the direction perpendicular to the horizontal direction.
[0022] Specifically Figure 2 The scanning bed to be calibrated 10, the four-axis linkage lifting structure 20, and the rotary encoder 30 are simplified as follows: Figure 3 The geometric relationships shown.
[0023] Specifically, the four-axis linkage lifting structure 20 includes an active swing arm AD, a driven swing arm BC linked to the active swing arm AD, and a first horizontal fixed rod AB and a second horizontal fixed rod CD for connecting the active swing arm AD and the driven swing arm BC. The first horizontal fixed rod AB is closer to the ground than the second horizontal fixed rod CD. The active swing arm AD includes a designated axis A and a first bed axis D. The driven swing arm BC includes a base axis B and a second bed axis C. The first bed axis D and the second bed axis C are rotatably connected to the ground of the scanning bed 10 to be calibrated. The designated axis A and the first bed axis D are rotatably connected to a base 40 fixed to the ground. In other words, the designated axis A, the first bed axis D, the base axis B, and the second bed axis C are all rotatable axes.
[0024] Furthermore, the first horizontal fixed rod AB includes a designated axis A and a base axis B that are movably connected to the rotary editor 30; the second horizontal fixed rod CD includes a first bed axis D and a second bed axis C of the scanning bed 10 to be calibrated.
[0025] The first extreme position of the scanning bed 10 to be calibrated is the highest mechanical point of the scanning bed (see details). Figure 3 The height of the scanning bed to be calibrated is H1), and the second extreme position is the lowest mechanical point of the scanning bed 10 to be calibrated.
[0026] During the calibration of the scanning bed, first adjust the scanning bed 10 to the first limit position (see details). Figure 3 The rotary encoder 30 obtains the first height value and the first horizontal position value of the scanning bed 10 to be calibrated, and records the first angle value output by the rotary encoder 30 at the first extreme position. The first height value is the vertical distance between the bottom surface of the scanning bed to be calibrated and the first horizontal fixed rod AB, for example, H1. The first horizontal position value is, for example, the spatial position value of the bottom surface of the scanning bed to be calibrated relative to the first horizontal fixed rod AB. For example, a three-dimensional coordinate system is established with a specified axis as the origin, where the first horizontal position value is the spatial position value in the three-dimensional coordinate system, for example, represented by S1. The first angle value is the angle value output by the rotary encoder 30 at the first extreme position of the scanning bed 10 to be calibrated (i.e., the angle formed by the active swing arm AD and the first horizontal fixed rod AB), for example, using... .
[0027] To improve the height measurement accuracy of the machine to be calibrated, the transmission ratio between the rotary encoder 30 and the specified shaft A is selected to be 1:5.
[0028] When the transmission ratio between the rotary encoder 30 and the designated shaft A is 1:5, the required rotational stroke accounts for 70% of the total stroke of the rotary encoder. After the transmission ratio is amplified, the stroke range on the rotary encoder side is approximately 350°, which is close to one revolution (i.e., 360°).
[0029] Because the rotary encoder needs to be repeatedly adjusted during installation so that its 0° position is approximately parallel to AB, this process requires repeated disassembly and reassembly of the encoder to ensure that the angle between the rotary encoder and the ground and the first horizontal fixed rod is zero. This achieves the physical position for aligning the rotary encoder with the horizontal line during installation.
[0030] The rotary encoder outputs encoded values in Gray code format, using values from 0 to 1024 to represent angles from 0 to 360°. When the rotary encoder rotates clockwise, the encoded value starts counting from 0, and restarts counting from 0 after exceeding the maximum value of 1024. When the encoder rotates counterclockwise, the encoded value starts counting from 1024, and starts counting from 1024 after falling below the minimum value of 0.
[0031] The current output value of the rotary encoder is represented by the following expression: in, This represents the current output value of the rotary encoder, i.e., the current angle formed by the active swing arm AD and the first horizontal fixed arm AB; This indicates the transmission ratio between the rotary encoder 30 and the specified shaft A; Indicates the current lap number; Indicates the current reading of the rotary encoder; This represents the angle calibration value calculated based on the first included angle of the scanning bed to be calibrated at the first defined position and the second included angle of the scanning bed to be calibrated at the second defined position.
[0032] Optionally, a single-turn absolute encoder is used to perform multi-turn counting to record the first angle value output by the rotary encoder 30 at the first extreme position.
[0033] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.
[0034] Next, in step S102, the scanning bed to be calibrated is adjusted to the second limit position, and the second height value and second horizontal position value of the scanning bed to be calibrated are obtained, and the second angle value output by the rotary encoder at the second limit position is recorded. Specifically, the scanning bed 10 to be calibrated is adjusted to the second limit position, that is, the lowest mechanical point of the scanning bed 10 to be calibrated, and the second height value and second horizontal position value of the scanning bed 10 to be calibrated are obtained, and the second angle value output by the rotary encoder 30 at the second limit position is recorded.
[0035] Optionally, the number of revolutions of the rotary encoder is determined for the first angle value and the second angle value to determine the first angle value and the second angle value by a multi-revolution counting method.
[0036] During the descent from the first extreme position to the second extreme position, the current value of the rotary encoder is determined to be in the first or second half of a revolution. If the current value is in the second half of a revolution and the reading suddenly decreases (optionally, from above 900 to below 100, for example, from 1024 to 0), it indicates that the rotary encoder has rotated more than one revolution in the forward direction, and the current revolution count is incremented by 1. Conversely, if the current value is in the first half of a revolution and the reading suddenly increases (optionally, from below 100 to above 900, for example, from 0 to 1024), it indicates that the rotary encoder has rotated more than one revolution in the reverse direction, and the current revolution count is incremented by 1. By counting the current revolutions and obtaining precise angles, and in conjunction with height compensation, the bed height and horizontal position of the bed to be calibrated at the current time can be accurately calculated.
[0037] It should be noted that the rotary encoder counts from 0 to 1024, and restarts the count from zero after each full rotation. The increment of the count is determined by detecting abrupt changes in the count value (from 1024 to 0 or from 0 to 1024).
[0038] The above are merely optional examples and should not be construed as limiting this application.
[0039] Next, in step S103, based on the first height value, the first horizontal position value, the first angle value, the second height value, the second horizontal position value, and the second angle value, the length of the active swing arm of the scanning bed to be calibrated and the angle calibration value are determined.
[0040] Based on the first height value, first horizontal position value, and first angle value obtained in step S101, and the second height value, second horizontal position value, and second angle value obtained in step S102, the length of the active swing arm of the scanning bed to be calibrated and the angle calibration value are calculated and determined.
[0041] The length of the active pendulum is calculated using the following expression: Where L represents the calculated length of the active swing arm in the four-axis linkage lifting structure; This represents the first height value of the scanning bed to be calibrated at the first extreme position; This represents the first horizontal position value of the scanning bed to be calibrated at its first extreme position; This represents the second height value of the scanning bed to be calibrated at the second extreme position; This represents the second horizontal position value of the scanning bed to be calibrated at its second extreme position; This represents the first angle value output by the rotary encoder at the first extreme position; This represents the second angle value output by the rotary encoder at the second extreme position.
[0042] It should be noted that, in this example, the length of the active swing arm of the scanning bed to be calibrated is expressed as the axial distance between the specified axis and the first bed axis D. The above is only an optional example and should not be construed as a limitation of this application.
[0043] To avoid the tedious operation of installing the rotary editor multiple times, and to obtain more accurate angle values output by the rotary encoder at different positions, it is necessary to make the angle between the rotary encoder and the ground and the first horizontal fixed rod zero, thus realizing the physical position of aligning with the horizontal line for zeroing during the installation of the rotary editor.
[0044] This application calculates an angle calibration value to directly adjust the position of the rotary encoder relative to the first horizontal fixed rod, effectively avoiding multiple installations and disassemblies of the rotary encoder. This improves the calibration process of the scanning bed to be calibrated.
[0045] The angle calibration value refers to the angle between the active swing arm and the first horizontal fixed arm near the ground in the four-axis linkage lifting structure when the output value of the rotary encoder is zero.
[0046] Based on the calculated length of the active pendulum, the angle calibration value is calculated using the following expression: in, This represents the angle calibration value calculated based on the first included angle of the scanning bed to be calibrated at the first defined position and the second included angle of the scanning bed to be calibrated at the second defined position; This represents the first included angle between the active swing arm and the horizontal fixed axis in the four-axis linkage lifting structure when the scanning bed to be calibrated is in its first extreme position; The angle between the active swing arm and the horizontal fixed axis in the four-axis linkage lifting structure is indicated when the scanning bed to be calibrated is in the second limit position; L represents the calculated length of the active swing arm in the four-axis linkage lifting structure. This represents the first height value of the scanning bed to be calibrated at the first extreme position; This represents the second height value of the scanning bed to be calibrated at the second extreme position.
[0047] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.
[0048] Next, in step S104, the height of the scanning bed to be calibrated at the current time is calculated based on the correlation determined by the calculated angle calibration value and the length of the active swing arm.
[0049] The height of the scanning bed to be calibrated at the current time is calculated using the following expression: in, The height of the scanning bed to be calibrated is indicated at the current time; L represents the calculated length of the active swing arm in the four-axis linkage lifting structure. This indicates the transmission ratio between the rotary encoder and the active swing arm in the four-axis linkage lifting structure; This indicates the current output value of the rotary encoder at the current time; This represents the angle calibration value calculated based on the first included angle of the scanning bed to be calibrated at the first defined position and the second included angle of the scanning bed to be calibrated at the second defined position; This indicates the vertical distance between the designated axis of the active swing arm near the ground and the ground in the four-axis linkage lifting structure, which can be obtained, for example, by measurement.
[0050] It should be noted that the above is only an optional example and should not be construed as a limitation of this application.
[0051] Compared with existing technologies, this application utilizes the structural feature of a rotary encoder and a four-axis linkage lifting structure with a movable connection to a specified shaft to obtain the height and horizontal position values of the scanning bed to be calibrated at the first and second extreme positions, and records the angle value output by the rotary encoder at the second extreme position. This allows for the calculation and determination of the length and angle calibration value of the active swing arm of the scanning bed to be calibrated. The length of the active swing arm (including compensation for machining errors) can be automatically calculated, and the calculated angle calibration value is used to directly adjust the position of the rotary encoder relative to the first horizontal fixed rod, effectively avoiding rotational errors. The repeated installation and removal of the encoder solves the problem of difficulty in aligning with the horizontal line during the installation of the rotary editor, thereby improving the calibration process of the scanning bed to be calibrated. Based on the correlation determined by the calculated angle calibration value and the length of the active swing arm, the height of the scanning bed to be calibrated at the current time can be calculated. This effectively simplifies the scanning bed calibration process, which originally required repeated installation and testing, to a single installation and two measurements. As a result, the labor cost required for debugging is greatly reduced, while also effectively increasing the height accuracy of the scanning bed to be calibrated.
[0052] Furthermore, by optimizing the algorithm for calculating the length and angle calibration value of the active swing arm of the scanning bed to be calibrated, more accurate angle calibration values and the length of the active swing arm can be obtained.
Claims
1. A method for calibrating the height of a scanning bed, characterized in that, include: The scanning bed to be calibrated is adjusted to a first extreme position, and a first height value and a first horizontal position value of the scanning bed to be calibrated are obtained. A first angle value output by the rotary encoder at the first extreme position is recorded. The scanning bed to be calibrated includes a four-axis linkage lifting structure and a rotary encoder connected to a designated shaft in the four-axis linkage lifting structure. The scanning bed to be calibrated is adjusted to a second extreme position, and a second height value and a second horizontal position value of the scanning bed to be calibrated are obtained. A second angle value output by the rotary encoder at the second extreme position is recorded. Based on the first height value, the first horizontal position value, the first angle value, the second height value, the second horizontal position value, and the second angle value, the length of the active swing arm of the scanning bed to be calibrated and its angle calibration value are determined. Based on the correlation determined by the calculated angle calibration value and the length of the active swing arm, the height of the scanning bed to be calibrated at the current time is calculated.
2. The scanning bed height calibration method according to claim 1, characterized in that, The length of the active pendulum is calculated using the following expression: Where L represents the calculated length of the active swing arm in the four-axis linkage lifting structure; This represents the first height value of the scanning bed to be calibrated at the first extreme position; This represents the first horizontal position value of the scanning bed to be calibrated at its first extreme position; This represents the second height value of the scanning bed to be calibrated at the second extreme position; This represents the second horizontal position value of the scanning bed to be calibrated at its second extreme position; This represents the first angle value output by the rotary encoder at the first extreme position; This represents the second angle value output by the rotary encoder at the second extreme position.
3. The scanning bed height calibration method according to claim 1 or 2, characterized in that, include: The angle calibration value is calculated using the following expression: in, This represents the angle calibration value calculated based on the first included angle of the scanning bed to be calibrated at the first defined position and the second included angle of the scanning bed to be calibrated at the second defined position; This represents the first included angle between the active swing arm and the horizontal fixed axis in the four-axis linkage lifting structure when the scanning bed to be calibrated is in its first extreme position; The angle between the active swing arm and the horizontal fixed axis in the four-axis linkage lifting structure is indicated when the scanning bed to be calibrated is in the second limit position; L represents the calculated length of the active swing arm in the four-axis linkage lifting structure. This represents the first height value of the scanning bed to be calibrated at the first extreme position; This represents the second height value of the scanning bed to be calibrated at the second extreme position.
4. The scanning bed height calibration method according to claim 1 or 2, characterized in that, include: The angle calibration value refers to the angle between the active swing arm and the first horizontal fixed arm near the ground in the four-axis linkage lifting structure when the output value of the rotary encoder is zero.
5. The scanning bed height calibration method according to claim 1, characterized in that, The step of calculating the height of the scanning bed to be calibrated at the current time based on the correlation determined by the calculated angle calibration value and the length of the active swing arm includes: The height of the scanning bed to be calibrated at the current time is calculated using the following expression: in, The height of the scanning bed to be calibrated is indicated at the current time; L represents the calculated length of the active swing arm in the four-axis linkage lifting structure. This indicates the transmission ratio between the rotary encoder and the active swing arm in the four-axis linkage lifting structure; This indicates the current output value of the rotary encoder at the current time; This represents the angle calibration value calculated based on the first included angle of the scanning bed to be calibrated at the first defined position and the second included angle of the scanning bed to be calibrated at the second defined position; This indicates the vertical distance between the designated axis of the active swing arm near the ground and the ground in the four-axis linkage lifting structure.
6. The scanning bed height calibration method according to claim 1, characterized in that, include The first angle value and the second angle value are used to determine the number of revolutions of the rotary encoder, so as to determine the first angle value and the second angle value by a multi-revolution counting method.
7. The scanning bed height calibration method according to claim 1, characterized in that, include: The first extreme position is the highest mechanical point of the scanning bed to be calibrated, and the second extreme position is the lowest mechanical point of the scanning bed to be calibrated.
8. The scanning bed height calibration method according to claim 1, characterized in that, The four-axis linkage lifting structure also includes a driven swing arm that is linked with the active swing arm, and a first horizontal fixed rod and a second horizontal fixed rod for connecting the active swing arm and the driven swing arm, wherein the first horizontal fixed rod is closer to the ground than the second horizontal fixed rod.
9. The scanning bed height calibration method according to claim 8, characterized in that, The first horizontal fixed rod includes a designated axis and a base axis that are movably connected to the rotary editor; the second horizontal fixed rod includes a first bed axis and a second bed axis of the scanning bed to be calibrated.
10. The scanning bed height calibration method according to claim 8, characterized in that, Based on the calculated angle calibration value and the calculated length of the active swing arm in the four-axis linkage lifting structure, the angle formed between the bottom surface of the rotary encoder and the first horizontal fixed rod can be zero.